Method of producing at least one end product via partial oxidation and/or oxidation of propylene in ammonia medium

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing at least one product from acrolein and acrylic acid via partial oxidation of propylene, where a) purified propane is converted at the first reaction step in the presence and/or absence of molecular oxygen, at least one dehydrogenation from a group comprising homogeneous dehydrogenation, heterogeneous catalytic dehydrogenation, homogeneous oxydehydrogenation and heterogeneous catalytic oxydehydrogenation, wherein a gaseous mixture 1 is obtained, which contains unconverted propane and the formed propylene, and b) optional separation from the total amount or partial amount of the gaseous mixture 1 of a partial amount of components other than propane and propylene contained therein, e.g., hydrogen, carbon monoxide, water vapour and/or optional conversion thereof to other compounds, e.g., water and carbon dioxide, and where a gaseous mixture 1' is obtained, which contains propane and propylene, and on at least one of the following reaction steps, c) the gaseous mixture 1 or gaseous mixture 1' or a mixture from the formed gaseous mixture 1' and the remaining gaseous mixture 1 as a component of a gaseous mixture 2 are subjected to heterogeneous catalytic gas-phase partial oxidation of propylene contained in gaseous mixture 1 and/or gaseous mixture 1', wherein a gaseous mixture 3 is obtained, which contains at least one product, d) on at least one separation step, the product is separated from gaseous mixture 3 and from the remaining residual gas, at least propane is returned to the first reaction step, where purified propane is obtained from crude propane which contains ≥90 wt % propane, ≤99 wt % propane and propylene, ≥100 ppm hydrocarbons, having 2 carbon atoms, and ≥100 ppm hydrocarbons, having 4 carbon atoms, under the condition that crude propane is fed into the fractionation column and purified propane is obtained higher than the feeding point under the condition that content of hydrocarbons having 2 carbon atoms, in wt %, in terms of the contained propane, in the purified propane is more than 100% of the corresponding content in crude propane and content of hydrocarbons having 4 carbon atoms, in wt %, in terms of content of propane, in the purified propane is at most 50% of the corresponding content in crude propane.

EFFECT: method enables to cut design expenses owing to no separation of C2-hydrocarbons during distillation.

48 cl, 1 ex

 

The proposed invention relates to a method for obtaining at least one target product by partial oxidation and/or ammonium oxidation in the environment of propylene, in which

a) pre-purified propane turn on the first stage of the reaction in the presence of and/or with the exclusion of molecular oxygen, at least one dehydrogenation of the group, including homogeneous dehydrogenation, heterogeneous catalytic dehydrogenation, homogeneous oxidisation and heterogeneous catalytic oxidisation, and get gas mixture 1 containing not converted propane and educated propylene, and

b) if necessary, of the total amount or a partial amount of the gas mixture 1, it contains components that differ from propane and propylene, separating the partial or total number and/or converted into other compounds, and moreover get the gas mixture 1'containing propane and propylene, and at least one following stage reaction

c) the gas mixture 1, or gas mixture 1', or a mixture formed from the gas mixture 1' and the remaining gas mixture 1 as a component of the gas mixture 2 is subjected to heterogeneous catalytic partial oxidation in the gas phase and/or partial oxidation in an ammoniacal medium in the gas phase propylene, soteriades is camping in the gas mixture 1 and/or gas mixture 1', and get gas mixture 3 containing at least one target product,

d) at least one stage of separation from the gas mixture 3 separate target product and with the remaining residual gas, at least, propane back to the first stage reaction.

Acrylic acid is an important monomer as a product of partial oxidation of propylene, which is used as such or in the form of its complex Olkiluoto ether to obtain, for example, polymers that are suitable as adhesives or super absorbent water (cf., for example, international patent application WO 02/055469 and WO 03/078378). Basically, the products of partial oxidation and/or oxidation in the ammonia environment propylene are important intermediate products for polymers and other products of partial oxidation or partial oxidation in an ammonia environment propylene (e.g., acrolein, Acrylonitrile, propylene oxide).

Obtaining acrylic acid and other products of partial oxidation of propylene as described in the beginning, it is known (cf., for example, German patent application DE-A 10245585 and DE-A 10246119).

Of the above documents is also known that the gas mixture 2 in such a process should be substantially free from hydrocarbons having 4 carbon atoms (abbreviated as4-Is) (including in this document, understand all the connections, built with 4 atoms of carbon and hydrogen; these include n-butane, ISO-butane, TRANS-butene-2, CIS-butene-2, butene-1, ISO-butene, butadiene-1,3, butadiene 1,2, 1-butyn and 2-butyn; in a corresponding way a hydrocarbon having 2 carbon atoms, are compounds built of 2 atoms of carbon and hydrogen (abbreviated as2-HC); they belong, in particular, ethane and ethylene; rather, the slave value is acetylene, as it unlike ethane and ethylene is usually in rather a scornful quantities than the admixture of propane), because the data connection, usually poison the catalysts required for partial oxidation. As a possible supporting measures for this in both documents recommend, if necessary, to carry out distillation pre-treatment of hydrocarbons having 4 carbon atoms contained in the crude propane.

In addition, from the above-mentioned documents, it is known that hydrocarbon having 2 carbon atoms, not forming any such catalytic poisons, why German patent application DE-A 10245585 and DE-A 10246119 have no similar specifications for hydrocarbon having 2 carbon atoms, in the gas mixture 2. On the contrary, in the above documents come from the fact that hydrocarbon having 2 carbon atoms (in particular, ethane, but also ethylene) when part of the nom oxidation behave as an inert gas for dilution. However, inert behavior is more likely in this respect, the lack of framework as initially described ways to control the circulating gas propane, when the circulation With3-HC necessary method requires a release (i.e. branches With2-HC from C3-HC) for such inert components, as in the framework of the method of controlling the circulation of their otherwise unlimited. The crude propane along with4-HC at the same time contains2-Hydrocarbons as impurities (what usually happens), so usually connect at least one issue With2-HC (in particular, in the case of ethane and ethylene as raw dirt propane With2-HC) with preliminary distillation of the Department With the4-Hydrocarbons from hydrocarbons having 4 carbon atoms contained in the raw propane as a raw stream of propane compared to all of the gas flows within the carrying out of circulation, as regards both its chemical composition and its volume is gas flow, adjustable relatively easily and with little cost.

Conversely, then, if possible, largely refuse such a preliminary separation With2if the relevant process from propane natural way of passing the circulation has the release With2-HC (so the first release in a natural way at first sight exists solely for at least one target product P). This is not least because the distillation of mixtures, from2-HC to C4-HC, in principle, be carried out at increased pressure. Otherwise require especially low temperature to obtain phlegmy required within the distillation column. The more theoretical plates required in a distillation column, the more, however, will be constructive costs generated during the column pressure (for example, all on the grounds reliable statics).

According to the invention now, in an unexpected way found that, in particular, hydrocarbons having 2 carbon atoms, ethane and ethylene as laboratory contaminants propane in the crude propane under conditions of heterogeneous catalyzed partial oxidation and/or ammonium oxidation in the environment of propylene to obtain, for example, acrolein, acrylic acid, propylene oxide and/or Acrylonitrile, usually only in this volume are inert under way for circulation provides a natural release2-Hydrocarbons contained in the gas mixture 2. As ethane and ethylene under normal conditions, the partial oxidation of propylene and/or ammonium oxidation in the environment sufficient way oxidize to obtain acetonitrile, ia a product is IDA and/or acetic acid, that goes with the separation of the target product, as a rule, sufficient way of issue of C2-HC in the form of acetonitrile, acetic acid and/or acetaldehyde (which are all more similar to the target product than its predecessors With2-HC).

Thus, according to the invention provide a method of obtaining at least one target product P by partial oxidation and/or ammonium oxidation in the environment of propylene, in which

a) pre-purified propane turn on the first stage of the reaction in the presence of and/or with the exclusion of molecular oxygen, at least one dehydrogenation of the group, including homogeneous dehydrogenation, heterogeneous catalytic dehydrogenation, homogeneous oxidisation and heterogeneous catalytic oxidisation, and get gas mixture 1 containing not converted propane and educated propylene, and

b) if necessary, of the total amount or a partial amount of the gas mixture 1, it contains components that differ from propane and propylene, separating the partial or total number and/or converted into other compounds, and moreover get the gas mixture 1'containing propane and propylene, and at least one following stage reaction

c) the gas mixture 1, or gas mixture 1', or a mixture of obrazovan the th gas mixture 1' and the remaining gas mixture 1 as a component of the gas mixture 2 is subjected to heterogeneous catalytic gas-phase partial oxidation and/or partial gas-phase oxidation in an ammonia environment propylene contained in the gas mixture 1 and/or gas mixture 1', and get gas mixture 3 containing at least one target product P,

d) at least one stage of separation from the gas mixture 3 separate target product and with the remaining residual gas, at least, propane back to the first stage reaction, which differs

that cleared propane from raw propane, which contains

≥90% of the mass. propane,

≤99% of the mass. propane and propylene (often ≤98 wt. -%, or ≤97 wt. -%, or ≤96 wt. -%, or ≤95% mass.),

≥100 mass. ppm hydrocarbon having 2 carbon atoms, and

≤100 mass. ppm of hydrocarbons having 4 carbon atoms,

get under the condition that the raw propane is transferred to distillation column (as a rule, have effectively separated built-in items) and above the place of filing take the purified propane provided that the content of hydrocarbons having 2 carbon atoms, in wt. -%, in the calculation contained propane, purified propane is not less than 80% of the relevant content in the raw propane, and the content of hydrocarbons having 4 carbon atoms, in wt. -%, in the calculation contained propane, purified propane is at most 50% of the relevant content in the raw propane.

In PR Dagenham according to the invention method, the raw propane, as a rule, contains ≥200 mass. ppm2-HC, often ≥300 mass. ppm2-HC, repeatedly ≥400 mass. ppm2-HC, or ≥500 masses. ppm2-HC, often ≥600 masses. ppm2-HC, or ≥700 mass. ppm2-HC and, if necessary, ≥800 masses. ppm2-HC, or ≥900 mass. ppm2-HC, or ≥1000 mass. ppm2-HC.

Of course, as proposed according to the invention method, the crude propane may also contain ≥1200 mass. ppm2-HC, or ≥1400 mass. ppm2-HC, or ≥1600 mass. ppm2-HC, or ≥1800 mass. ppm2-HC, or ≥2000 mass. ppm2-HC. Possible content2-Hydrocarbon used according to the invention the crude propane can also be ≥3000 mass. ppm, or ≥5000 mass. ppm, or ≥7000 mass. ppm, or ≥10000 mass. ppm. According to the definition of the content With2-HC in applied according to the invention the crude propane necessary way is below 10 wt. -%, often, when values of ≤8% wt., many times, when values of ≤7% wt., or ≤6 wt. -%, or ≤5% of the mass.

Typically, at least 90 wt. -%, many times, at least 92 wt. -%, or, at least 94 wt. -%, or, at least 96 wt. -%, or at least 98 wt. -%, or, at least, 99% of the mass. content2-HC in raw fall on propane ethane and ethylene. The content of the acetylene is calculated on the total number of2-The, contained in the crude propane, often with values ≤1 wt. -%, many times, when values of ≤0.5% wt., and often, when values of ≤0.3% wt., or ≤0.1% of the mass.

Often found in raw propane total number With2-HC, at least 50 wt. -%, many times, at least 60 wt. -%, often, at least 70 wt. -%, often, at least 80 wt. -%, and partially, at least 90 wt. -%, falls on ethane.

The ethylene content in the crude propane in many cases, based on the total number of the contained hydrocarbon may be, however, up to 50% of the mass.

As a rule, as proposed according to the invention method, the crude propane contains ≥200 mass. ppm4-HC, often ≥300 mass. ppm4-HC, repeatedly ≥400 mass. ppm4-HC, or ≥500 masses. ppm4-HC, often ≥600 masses. ppm4-HC, or ≥700 mass. ppm4-HC and, if necessary, ≥800 masses. ppm4-HC, or ≥900 mass. ppm4-HC, or ≥1000 mass. ppm4-HC.

Of course, as proposed according to the invention method, the raw propane may also contain ≥1200 mass. ppm4-HC, or ≥1400 mass. ppm4-HC, or ≥1600 mass. ppm4-HC, or ≥1800 mass. ppm4-HC, or ≥2000 mass. ppm4-HC.

Possible content4-HC in applied according to the invention the crude propane can also be ≥3000 mass. ppm, or the 5000 mass. ppm, or ≥7000 mass. ppm, or ≥10000 mass. ppm. According to the definition of the content With4-HC in applied according to the invention the raw propane necessary way is below 10 wt. -%, often, when values of ≤8% wt., many times, when values of ≤7% wt., or ≤6 wt. -%, or ≤5% of the mass.

In many cases, at least 80 wt. -%, many times, at least 90 wt. -%, or, at least 92 wt. -%, or, at least 94 wt. -%, or, at least 96% of the mass. content4-Hydrocarbons in the crude propane falls on butane (n-butane and ISO-butane). Contained in the crude propane, butane, usually ≥50 wt. -%, often ≥60 wt. -%, repeatedly ≥70% of the mass. falls on ISO-butane. Accordingly, concerning the content of n-butane in most cases is when ≥10% of the mass.

The total content of butenes, based on the total number of4-Hydrocarbons contained in the crude propane is often at values ≤1 wt. -%, many times, when values of ≤0.5% wt., and often, when values of ≤0.3% of the mass. or ≤0.1% of the mass.

Typically, however, the crude propane contains ≥10% of the mass. ppm of butenes.

The content of pre-purified propane to ISO-butane is ≤1000 mass. parts per million, in particular ≤100 mass. parts per million

The crude propane also contains hydrocarbons having five or more carbon atoms, so that, while proposed according to which obreteniyu distillation pre-treatment is separated together with hydrocarbons, having 4 carbon atoms. Typically, the total content of C≥5-Hydrocarbons in the crude propane is characterized by higher content4crude propane (usually less than 50 wt%. content4-HC or even less). Such is also suitable for methane, optionally contained in the crude propane. However, with the difference that his fate is essentially equal to2-HC (i.e. according to the invention edition2-HC, as a rule, in an appropriate way is also the issue of C1-HC).

Often the total content of C≥5-HC and methane (but also both the individual content in the raw propane is at values of ≤0.5% wt., or ≤0.3% wt., or ≤0.1% of the mass.

According to the invention preferably is proposed according to the invention the method is carried out in such a way that related to any propane content of hydrocarbons having 4 carbon atoms, in % of the mass. in purified propane is a maximum of 40%, preferably a maximum of 30%, even better at most 20%, particularly preferably up to 10% and highly preferably a maximum of 5% or a maximum of 1% of the corresponding content in the crude propane.

In addition, the assumption according to the invention the method is carried out preferably in such a way that related to contained the propane content of hydrocarbons having 2 carbon atom is kind, in % of the mass. in purified propane is not less than 85%, preferably not less than 90%, especially preferably not less than 95 wt. -%, better yet, not less than 100% and highly preferably more than 100% (typically not more than 110% and in most cases not more than 105%) of the corresponding content in the crude propane. That is, in the highest degree preferably proposed according to the invention the method is carried out in such a way that the purified propane enriched hydrocarbon having 2 carbon atoms, based on the contained propane, compared to similarly related content hydrocarbon having 2 carbon atoms, in the crude propane. According to the invention reason for the above is already described the natural release for C2-HC in the framework proposed according to the invention the circulation method.

According to the invention is further beneficial if the proposed according to the invention of the distillation pre-treatment of crude propane is conducted in such a way that withdrawn from the distillation column purified propane has as content of ISO-butane and content With4-HC ≤1000 mass. cnnnn, or ≤900 mass. cnnnn, or ≤ 800 masses. cnnnn, or ≤700 mass. cnnnn, or preferably ≤600 masses. cnnnn better yet ≤500 masses. cnnnn, or ≤ 400 mass. CN is ln., or ≤300 mass. cnnnn and better yet ≤200 mass. cnnnn In many cases, the content proposed according to the invention is pre-purified propane to ISO-butane is, however, ≥100 mass. cnnnn

Within the distillation column used for the proposed according to the invention prior to separation, bring together the descending liquid phase (phlegm) and the ascending vapour phase in countercurrent. Due to temperature and concentration gradients arising between the flows of substances, there is a heat exchange and mass transfer, which causes the desired separation of substances. As a rule, to increase the surface mass transfer in distillation column are effectively separated by the built-in elements. As such embedded elements for proposed according to the invention, a method is used, in principle, effectively separated built-in items of any kind. This can be, for example, nozzles, filling fillers and/or plates for mass transfer of any kind. Plates for mass transfer, in which the equilibrium prevailing between the liquid and an ascending vapor, is designated as a theoretical plate. This concept can be transferred to all other appropriate for rectificate in a counter, effectively separated the built-in elements (for example, nozzles and filling Napo is the distributors). Therefore, in this document a reasonable way at all to say about theoretical separation stages. Moreover, as a theoretical separation stages define the unit of volume, which contributes to the enrichment or depletion, respectively thermodynamic equilibrium.

According to the invention preferably effectively divided inline elements are plates for mass transfer. As such for proposed according to the invention, a method is used sieve trays (such forced conducting fluid and such without forced conducting fluid (e.g., all described in the German patent application DE-A 10347664)), and particularly preferably the valve plates. Under the valve in this document should be understood plates with cross-flow, which have holes on the plate with Poppet valves, ballast valves or lifting valves with limited lifting (float valves), that fit the size of the transition hole pair to the corresponding load of the column. The upward gas flow is rejected, flows parallel to the plate in saprogenous the phlegm and forms a flowing layer. Reinforced drain pipes are phlegm from plate to plate. They often presents a two-line. But they also mo is ut to be represented three-flow and multi-threaded (e.g., out four-flow).

The heat required for proposed according to the invention rectification, is suitable manner, for example, through located inside and/or outside the heat exchanger of conventional design, and/or by using double-walled heating. Often used located outside the circulation evaporation apparatus with natural or forced circulation.

According to the invention it is possible to use several in series or connected in parallel evaporators. As the heat can be applied, for example, water vapor, which occurs within the heat transfer by partial oxidation in the gas phase is usually in a natural way.

As a rule, proposed according to the invention the formulation of the problem in the framework proposed according to the invention pre-treatment of raw propane is achieved using only a single distillation column, which has at least 5 theoretical stages of separation, often at least 8 theoretical stages divisions, many times, at least 10 theoretical stages of separation and often at least 14 theoretical stages of separation. However, usually need no more than 25 theoretical stages of separation, often not more than 23 theoretical stage split the times and not more than 21 theoretical separation stage. In many cases, the number of theoretical stages of separation is at 15-20, such as at 18.

Based on the relatively low number of separation stages (raw propane contains other than propane, With3-HC as components (e.g., propylene), within3-HC in the framework proposed according to the invention pre-treatment basically there is no separation; it is also not required, since propylene is required reagent in the gas mixture 2; cyclopropane is usually, at least in negligible quantities of raw components propane), proposed according to the invention method can be carried out without excessive structural expenditure under the pressure of the upper part (in a distillation column) ≥5 bar. That is, according to the invention the pressure in the upper part can be ≥7 bar, or ≥9 bar, or ≥11 bar, or ≥13 bar, or ≥15 bar. Typically, however, the pressure in the upper part is when the values are ≤25 bar, or ≤23 bar, or ≤21 bar.

Based on the above ratios, the pressure in proposed according to the invention method, the temperature in the lower part of the column is typically at values of ≤100°C. According to the invention favourable temperature in the lower part of the column ranges from 40 to 90°C., preferably from 50 to 90°C. and especially preferred is sustained fashion from 60 to 80°C. Thus, a relatively low temperature in the lower part of the column are relatively low amount of deposition or formation of the crystalline crust (sediment, polymers) in the lower region of the column.

Pre-purified propane can be removed as in the upper part of the distillation column, and through the side fences of the distillation column. Often these fences occur liquid (for example, through the bottom of the pipe for exhaust gases). In the case of the side fences above the fence is usually at most before 2 theoretical stages of separation.

Based on the above ratios, the pressure in proposed according to the invention the method is usually sufficient cooling water of the condenser, the upper part (including produces phlegm). Thus according to the invention it is expedient we are talking about indirect shell-and-tube heat exchanger or a plate heat exchanger, which put on a distillation column, or you can embed in a distillation column. In the conventional method, the temperature of cooling water through the heat exchanger (added to the capacitor upper part)is ≥0°C and ≤40°C. That is, the normal temperature of the cooling water at ≥5°C and ≤35°C or ≥10°C and ≤30°C. Frequently used cooling water temperature of 20°is.

Typically, the capacitor upper part has ventilation, which helps to release with great difficulty able to condensation of the components of the raw propane, such as, for example, N2, CO2etc.

The ratio of the amount (kg/h) phlegmy returned in the upper part of the column, the number of unprocessed propane added to the distillation column at proposed according to the invention the method of pre-cleaning in the usual way is from 1 to 2.5, often from 1.5 to 2.5 and often from 1.5 to 2.0.

According to the invention particularly preferably education phlegmy carried out in such a way that a partial quantity relative to this condensation from the gas phase remains gaseous, so that the cleared propane required for proposed according to the invention of the method in the first stage, you can add directly withdrawn from the distillation column in a gaseous form (gaseous top or side fence).

The supply of raw propane into the distillation column at proposed according to the invention the method is technologically appropriate in all cases carried out in such a way that at least one theoretical stage of separation is above the inlet, and at least one theoretical stage of separation is below the filing. As ravelo, the number of theoretical stages of separation above the inlet (ZOshould be greater than the number of theoretical stages of separation below the inlet (ZU).

Often the ratio of ZOto ZUwhen proposed according to the invention the method is from 1.1 to 2, often from 1.1 to 1.5 and repeatedly from 1.1 to 1.3.

Mostly of4-HC (primarily n-butane and ISO-butane) consisting of the lower part of the column is continuously removed from the distillation column and technologically expedient to add to the material following application (for example, to obtain the synthesis gas, partial oxidation, combustion). In the most simple way such material following the application looks, for example, so that the waste liquid in the form of a joint submission (paraffinic hydrocarbons) lead to the cracking furnace (e.g., steam cracking unit and/or the cracking unit for refining), which by thermal cleavage of paraffin hydrocarbons receive lower saturated and unsaturated hydrocarbons (for example, C3-HC and4-HC) and separate distillation method in the so-called columns with divisor (cf., for example, U.S. patent 3392216). In this way, the cubic liquid used hereinafter, can be proposed according to the invention of the distillation prior Department is of particularly simple way with comparatively in this respect, a slight sharpness, what waste liquid contains up to 30% of the mass. With3-HC (usually the contents of this3-HC is ≤20 ≤10 wt. -%). If you are seeking an alternative material for the next use, the waste liquid, usually more strongly depleted With3-HC. This depletion may occur, if necessary, by distillation processing of the bottom liquid of the second distillation column, as described in the German patent application DE-A 2413463. You get the following according to the invention applied pre-purified propane.

Preferably used according to the invention of the distillation column, including effectively divided plates for mass, preferably made of stainless steel. Suitable distillation column you can insulate on the outside materials, such as, for example, glass wool or mineral wool, rigid foam, cork or Armaflex®.

If in a distillation column used nozzles and/or backfill fillers as effectively divided inline elements, they can be composed, for example, rings, spirals, saddles, Raschig rings, rings INTAS or rings PAL, saddles the Burleigh or Intalox, top-Pak or braids. Of course, the distillation column can contain all named in this document is ente possible column integrated in mixed form.

The pressure loss through the distillation column is typically at values ≤1 bar. The supply of crude propane distillation column is a technologically expedient in such a way that the crude propane is a liquid to at least 95 wt. -%, preferably up to at least 97 wt. -%, or to at least 99% of the mass. The temperature of the molten crude propane may correspond to the temperature which occurs at the place of submission within the distillation column (temperature control can occur, for example, by heat exchange with ambient air). But they can also be within this temperature. Usually the supply of crude propane distillation column occurs through the device to reduce the pressure (e.g., throttle).

As a rule, in the framework proposed according to the invention pre-treatment getting used according to the invention pre-purified propane, which usually consists of up to at least 99 wt. -%, preferably to at least 99.5% of the mass, and especially preferably to at least 99.7% of mass., highly preferably to at least 99.9% of the mass. and it is best to at least 99.95% of the mass. or to at least 99.99% of the mass. of propane, propylene, ethane and ethylene. In the usual method of part C2-What is ≤5 wt. -%, often ≤3 wt. -%, repeatedly ≤2 wt. -%, often ≤1% of the mass. and sometimes ≤0.5% mass. (in most cases it is, however, with ≥0.1% of mass). As a rule, ≥50% wt., often ≥60 wt. -%, often ≥80 wt. -%, or ≥90 wt. -%, or ≥95 wt. -%, or ≥98 wt. -%, or ≥99% of the mass. falls on ethane.

This pre-purified propane can then be used according to the invention. This may occur, for example, as described in documents of German patent application DE-A 10245585, German patent application DE-A 10246119, international patent application WO 01/96270, U.S. patent 3161670, German patent application DE-A 3313873, international patent application WO 01/96271, international patent application WO 03/011804, international patent application WO 03/076370, German patent application DE-A 10316039, German patent application DE-A 102004032129, European patent application EP-A 117146, international patent application WO 04/031106, German patent application DE-A 10316039, German patent application DE-A 19508558, German patent application DE-A 19837520, German patent application DE-A 19837519, German patent application DE-A 19837517, international patent application WO 97/36849, European patent application EP-A 1106598, European patent application EP-A 274681, European patent application EP-A 731077, German patent application DE-A 102005009885, German patent application DE-A 102005009891 and German patent application DE-A 102004003212.

Under oxidase what risovaniem propane in this document to understand the dehydrogenation, which cause the audience oxygen and in which the intermediate is not formed no free hydrogen or is provable. Unlike conventional dehydrogenation, which is endothermically, thermal effect of oxidisation is exothermic. Oxidisation propane can also be carried out when exposed to elevated temperature as homogeneous (i.e. without the presence of, for example, the solid catalyst; cf., for example, U.S. patent 3798283)and heterogeneous catalytic (e.g., solid catalysts; cf., for example, German patent application DE-A 2058054 and DE-A 19530494). Often both reactions proceed in parallel. Such matters essentially for conventional dehydrogenation, at which stage dehydrogenation occurs without total active oxygen (cf., for example, European patent application EP-A 731077 and international patent application WO 01/96270). That is, a primary by-product, there is a hydrogen, not water, as in the case of oxidisation. In the secondary reaction of the formed molecular hydrogen can, of course, partially or completely burned.

Under the complete oxidation of propylene in this document understand that the carbon contained in the whole propylene is converted into carbon oxides (CO, CO2). All of this great prevremeni the propylene reactive effect of molecular oxygen combine in this document with the notion of partial oxidation. Additional reactive effects of ammonia means the oxidation of ammonia to the environment. Under suitable ammonia are parallel layering partial oxidation and oxidation in the ammonia environment (compare German patent application DE-A 10245585). In this document, the preferred products of the partial oxidation of propylene and/or oxidation of propylene in the ammonia environment are acrolein, acrylic acid, propylene oxide and Acrylonitrile.

As the oxidant gas mixture 2 contains molecular oxygen which may be present in the gas mixture 2, for example, in pure form or in mixtures with gases (such as air), remaining essentially inert relative to the partial oxidation/oxidation in an ammonia environment. Often the reagents in the gas mixture 2 is also on the grounds of the heat sink and on the grounds reliable the reaction is diluted with at least one inert gas (for example, N2H2O, CO, CO2rich, for example, hydrocarbons having from 1 to 5 carbon atoms (for example, according to the German patent application DE-A 1924431 and European patent application EP-A 293224), and/or AG and so on).

All the implementation in this document, then, in particular, confirmed, if partial oxidation of propylene contained in the gas mixture 2 is a partial oxidation is ropylene to acrolein and/or acrylic acid.

When this gas mixture 2 preferably has the following contents:

from 6 to 9% of the mass. propylene,

from 8 to 18% of the mass. molecular oxygen,

from 6 to 35% of the mass. propane and

from 32 to 72% of the mass. molecular nitrogen.

The molar ratio of V1propane contained in the gas mixture 2, the propylene contained in the gas mixture 2 is thus according to the invention favorably from 1 to 4. The molar ratio of V2molecular nitrogen contained in the gas mixture 2, to molecular oxygen contained in the gas mixture 2 is thus according to the invention suitable from 2 to 6. The molar ratio of V3molecular oxygen contained in the gas mixture 2, the propylene contained in the gas mixture 2 is thus according to the invention is preferably from 1.3 to 2.4.

In addition, it is known that in the sense of preventing unwanted complete combustion of propylene partial oxidation and/or the oxidation of ammonia to the environment are mostly favourable, if the content of propane in the gas mixture 2 is relatively limited. According to the invention, preferably the content of propane in the gas mixture 2≤60% of the mass. or ≤50% of the mass. Particularly favorable are the content of propane in the gas mixture 2 from 20 to 40 wt. -%, for example, approximately 30% of the mass.

If auscultation ammonia, jointly applied to produce the nitrile (i.e. it does not take into account the basis of the relationship for wt. -%), for proposed according to the invention, a method is generally suitable gas mixture 2, which contain:

from 7 to 15% of the mass. O2,

from 5 to 10% of the mass. propylene,

from 15 to 40% of the mass. propane, often from 25 to 35 wt. -%,

from 25 to 60% of the mass. nitrogen, often from 40 to 60 wt. -%,

from 1 to 5% of the mass. the amount of CO, CO2and H2O and

from 0 to 5% of the mass. other components (e.g., H2).

However, it is proposed according to the invention the method can be various main options described in the prior art (cf., in particular, the German patent application DE-A 10245585). That is, in the simplest case, all the reaction stages is proposed according to the invention the method is carried out in one (single) reaction zone and within it, the catalyst loading, as described in European patent applications EP-A 608838, EP-A 529853, German patent applications DE-A 19835248, DE-A 10145958 and DE-A 10145958, and also DE-A 10245585 and are included in these documents, such as retrieving acrolein and/or acrylic acid.

When applied to the active mass loading of the catalyst used for this preferred mass of oxides multimetallic that contain the following combinations of elements in the stoichiometry I:

,

where

M1= Te and/or Sb,

M2= at least one element from the group including Nb, TA, W, Ti, Al, Zr, Cr, Mn, Ga, Fe, Ru, Co, Rh, Ni, Pd, Pt, La, Bi, Ce, Sn, Zn, Si, Na, Li, K, Mg, Ag, Au and In,

b = from 0.01 to 1,

with = > from 0 to 1, and

d = > from 0 to 1,

or consist of this combination of elements in oxide form.

Then they are, in particular, the active mass of oxides multimetallic overall stoichiometry II

,

moreover, the variables have the meaning given relative to the stoichiometry of I, and n = the number that is determined through the valence and a lot different from the oxygen elements in (II).

According to the invention, it is preferable to M1=Te and M2=Nb, TA, W and/or Ti.

Preferably M2=Nb. The stoichiometric coefficient b is preferably from 0.1 to 0.6. In a corresponding way, the preferred region for the stoichiometric coefficients is from 0.01 to 1, or from 0.05 to 0.4 and favorable values for d are from 0.01 to 1 or from 0.1 to 0.6.

Preferably the active mass of the oxides of multimetallic stoichiometry II has a crystalline structure and surface properties, described in the German patent application DE-A 10245585. Described active mass of oxides multimetallic can be formed as such (i.e. in powder form) or to the appropriate geometries (with the Avni, for example, shell catalysts German patent application DE-A 10051419 and apply geometric variants of German patent application DE-A 10122027) for one zone of the form proposed according to the invention method (excluding phase separation). They are suitable, in particular, to obtain acrolein and/or acrylic acid, as well as to obtain Acrylonitrile. The basis for this alarm mode of action is that the used catalysts can catalyze all the reaction stages is proposed according to the invention method.

According to the invention is substantially that described in the alarm mode of action of ethane and ethylene is partially oxidized and/or oxidized in an ammonia environment, as proposed according to the invention method to acetonitrile, acetaldehyde and/or acetic acid.

Described single-band method steps can be performed in a fixed bed of catalyst in the fluidized bed of the catalyst or the movable layer (moving layer). Corresponding descriptions of the method are found in the documents of the prior art. If a proposed according to the invention the method is carried out, for example, to obtain acrylic acid in the alarm mode of action as a reaction in a fixed bed, it is expedient way conduction occurs in a shell-and-tube reactor, whose contact t the UBA loaded catalyst. Around the contact tube is normally conducting liquid as a coolant, usually molten salt. Alternative you can also apply thermoplasticity the reactor, and the catalyst loading is in the form of smooth layout between the cooling plates.

The reaction gas mixture is carried out, watching through the reactor in contact tubes either in co-current or counter-current to the salt bath. Salt bath itself can make pure parallel and over the contact tubes. But also, of course, can be layered cross over. In General, the salt bath can also perform flow around the contact tube, which is carried out only watching through the reactor in co-current or countercurrent to the reaction gas mixture. Shell-and-tube reactors suitable for the proposed according to the invention method, describe, for example, in the documents of the European patent applications EP-A 700714 and EP-A 700893.

Various possible compositions of the initial mixtures of the reaction gases for the single-band version proposed according to the invention method can be gathered from the prior art described in connection with this option. To obtain the acrylic acid composition of the starting reaction gas mixture in the usual way moves within the following framework (molar ratios):

P is open:oxygen:H 2O:other components (especially inert gases for diluting)=1:(0,1-10):(>0-50):(>0-50).

Preferably, the above ratio is 1:(0.5 to 5):(1-30):(1-30).

The above areas have value, particularly when the quality of the other components used primarily of molecular nitrogen. The reaction temperature is usually from 250 to 550°C (conditions for the oxidation of ammonia to the environment compared refuse from the fact that the reaction gas mixture comprises more ammonia (cf., for example, European patent application EP-A 529853)).

Load load catalyst fixed bed catalyst propane can be when two mono version proposed according to the invention method, for example, from 10 to 500 Nl/l (fixed layer)*including Load the original mixture, the reaction gas is often in the range from 100 to 10000 Nl/l·h, frequently in the range from 500 to 5000 Nl/l·h

Recommended for single-band image of the effective mass of oxides multimetallic as proposed according to the invention the method can be applied, of course, also in the form, diluted with finely ground, for example, colloidal materials, such as silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide and niobium oxide.

When this mass ratio for dilution may be the about 9 (diluent):1 (active mass). That is, the possible mass ratio for dilution is, for example, 6 (diluent):1 (active mass) and 3 (diluent):1 (active mass). While the introduction of the diluent may occur according to the German patent application DE-A 10122027 before or after the calcination. Of course, for proposed according to the invention single-band image of the steps can also be applied to other systems of catalysts, such as, for example, described in Japanese patent application JP-A 3170445. If a proposed according to the invention the method is carried out in the reaction zone, there is one case in which the gas mixture 1 and the gas mixture 2 are identical.

According to the invention preferably is proposed according to the invention the method is carried out in more than one reaction zone, as described in European patent applications EP-A 938463, EP-A 117146, German patent application DE-A 3313573, British patent application GB-A 2118939, U.S. patent 3161670, international patent application WO 01/96270, European patent application EP-A 731077, German patent applications DE-A 19837520, DE-A 19837517, DE-A 19837519, DE-A 19837518, DE-A 19837520, DE-A 10131297 and DE-A 10211275.

When more than one reaction zone has in mind, first of all, they spend at least one reaction stage is proposed according to the invention the method and conditions that can be selected, n is at least partially independently from the at least one other reaction stage within proposed according to the invention method, or, however, only in the second place, within the same reaction stages along the reaction path are at least partially independently of each reaction conditions (the latter happens, for example, when one of the reaction stages use the so-called multi-band images of action (independently of each adjustable temperature zones), as, for example, described in German patent applications DE-A 19948241, DE-A 19927624, DE-A 19910508, DE-A 19910506 and DE-A 19948248). To have proposed according to the invention the method includes, for example, two reaction stages, so for the first reaction stage is used, for example, one other catalyst or a different catalyst loading than for the second reaction stage. Or it is possible to approach so that the application of identical catalysts or download catalysts for both reaction stages you can choose and regulate the reaction temperature for both reaction stages independently of each other. Of course, both can also be used layered.

The advantage of a multi-band image action is based on the fact that he basically promotes improved proposable what the reaction conditions to the requirements of the individual reaction stages is proposed according to the invention method.

This advantage is well known from heterogeneous catalyzed partial oxidation in the gas phase propylene to acrylic acid with molecular oxygen.

It proceeds along the reaction coordinate, following each other along the reaction coordinate, in principle, in two stages, the first of which results in acrolein and the second from acrolein to obtain acrylic acid.

This over reaction in a known manner opens the possibility to implement proposed according to the invention the partial oxidation of propylene contained in the gas mixture, in two sequentially located oxidation zone, and in each of the two zones of oxidation can be coordinated by an optimization method used oxidation catalyst (this option negotiation also allows to stop the partial oxidation of propylene level acrolein and to separate acrolein). Thus, for the first oxidation zone (propylene→acrolein), as a rule, the preferred catalyst is based on a combination of elements Mo-Bi-Fe-containing oxide multimetallic, while for the second oxidation zone (acrolein→acrylic acid) are preferred conventional catalysts based on combinations of the elements Mo-V containing oxides of multimetallic (such as those recommended in this document on the I single-band image). In principle, these two reaction stages can also be carried out in a single reaction zone and on the sole catalyst.

Quite versatile when proposed according to the invention the method is suitable, the first reaction stage is carried out in a separate reaction zone.

If oxidisation propane it can be in the form of homogeneous and/or heterogeneous catalyzed oxidisation propane to propylene with molecular oxygen in the gas phase. Moreover, as the source of molecular oxygen can be used air, pure molecular oxygen or air enriched with molecular oxygen (within oxidisation is usually partial oxidation With2-HC; this facilitates the appropriate release after oxidisation).

A reaction zone is formed in the form of a homogeneous oxidisation thus, it can, in principle, be carried out, as described, for example, in documents U.S. patent 3798283, CN-A 1105352, Applied Catalysis, 70(2)1991, C-187, Catalysis Today 13, 1992, s-678 and in the application at the German patent DE-A 19622331. Suitable source of oxygen is air. The temperature of the homogeneous oxidisation choose lying expedient in the region from 300 to 700°C., preferably in the region from 400 to 600°C., particularly preferably in the region from 400 to 50°C. The operating pressure may be from 0.5 to 100 bar, in particular from 1 to 10 bar. Processing time is usually at 0.1, respectively, from 0.5 to 20 seconds, preferably at 0.1, respectively, from 0.5 to 5 seconds.

As the reactor can be used, for example, a tube furnace or a shell and tube reactor, as, for example, countercurrent tubular furnace with flue gas as a coolant or a shell and tube reactor with salt melt as the heat carrier. The ratio of propane to oxygen in the mixture is preferably from 0.5:1 to 40:1, in particular between 1:1 to 6:1, even more preferably between from 0:1 to 5:1. The initial mixture may also include the following, preferably inert (under inert ingredients in this document it is necessary to understand in General preferably such components, which are converted at the relative reaction stage to less than 5 wt. -%, preferably to less than 3% of the mass. and especially preferably to less than 1 wt. -%; highly preferably they do not turn) components, such as water, carbon dioxide, carbon monoxide, nitrogen, noble gases, other hydrocarbons (e.g., side components contained in the raw propane)and/or propylene, etc. and it can also be returned (the circulating gas is) components.

Dehydrogenation of propane formed in the form of heterogeneous catalyzed oxidisation thus, it can, in principle, be carried out, as described, for example, in documents U.S. patent 4788371, CN-A 1073893, Catalysis Letters 23 (1994), 103-106, W. Zhang, Gaodeng Xuexiao Huaxue Xuebao, 14 (1993) 566, Z. Huang, Shiyou Huagong, 21 (1992) 592, international patent application WO 97/36849, German patent application DE-A 19753817, U.S. patents 3862256, 3887631, German patent application DE-A 19530454, U.S. patent 4341664, J. of Catalysis 167, 560-569 (1997), J. of Catalysis 167, 550-559 (1997), Topics in Catalysis 3 (1996) 265-275, U.S. patent 5086032, Catalysis Letters 10 (1991), 181-192, Ind. Eng. Chem. Res. 1996, 35, 14-18, U.S. patent 4255284, Applied Catalysis A: General, 100 (1993), 111-130, J. of Catalysis 148, 56-67 (1994), V. Cortes Cor-beran, S. Vic Bell6n (Ed.), New Developments in Selective Oxidation II, 1994, Elsevier Science B.V., p. 305-313, 3rdWorld Congress on Oxidation Catalysis, R.K. Grasselli, S.T. Oyama, A. M. Gaffney and J.E. Lyons (Ed.), 1997, Elsevier Science B.V., p. 375 FF. Or in the German patent applications DE-A 19837520, DE-A 19837517, DE-A 19837519 and DE-A 19837518. Moreover, as the source of oxygen you can also use the air. However, often the source of oxygen has at least 90% of the mass. molecular oxygen, and repeatedly, at least 95% of the mass. the oxygen.

Catalysts suitable for heterogeneous catalyzed oxidisation, not subject to any particular limitations. Suitable are all catalysts for oxidisation known to the person skilled in the art that in the first the second turn oxidize propane to propylene. In particular, it is possible to use all catalysts for oksigenirovannym named in the above-mentioned documents. Suitable catalysts are, for example, catalysts for oxidisation, which include oxides of Mo-V-Nb or pyrophosphate of vanadia, optionally with a promoter. Favorable catalyst for oxidisation is, for example, the catalyst, which is also recommended for single-band image of action, which contains a mixed oxide of the metals Mo, V, Te, O and X as the most important components, and X is at least one element selected from niobium, tantalum, tungsten, titanium, aluminum, zirconium, chromium, manganese, gallium, iron, ruthenium, cobalt, rhodium, Nickel, palladium, platinum, antimony, bismuth, boron, indium, silicon, lanthanum, sodium, lithium, potassium, manganese, silver, gold and cerium (also compare European application EP-A 938463 and EP-A 167109). In addition, particularly suitable catalysts for oxidisation are mass of oxides multimetallic or catalysts And German patent application DE-A 19753817 and catalysts German patent application DE-A 19838312, and in the highest degree favourable mass of oxides multimetallic or catalysts And named as preferred in the first document. That is, as the active mass can be used in h is particularly mass of oxides multimetallic General formula III

and

M1=Co, Ni, Mg, Zn, Mn and/or si,

M2=W, V, Te, Mb, P, Cr, Fe, Sb, Ce, Sn and/or La,

a=0.5 to 1.5,

b=0-0,5,

and

x = the number that is determined through the valence and a lot different from the oxygen elements in (III).

Receiving and shaping can occur, as described in the German patent application DE-A 10245585.

For heterogeneous catalyzed oxidisation propane, the reaction temperature is preferably in the range from 200 to 600°C., in particular in the region from 250 to 500°C., more preferably in the range of 350 to 440°C. the Operating pressure is preferably in the range from 0.5 to 10 bar, in particular from 1 to 10 bar, more preferably from 1 to 5 bar. As especially preferred is working pressures above 1 bar, for example, from 1.5 to 10 bar. Typically, heterogeneous catalyzed oxidisation propane occurs on the fixed catalyst bed. The latter expedient is poured into the tube shell-and-tube reactor, as described, for example, in European patent applications EP-A 700893 and EP-A 700714, as well as the references cited in these papers. Average processing time of the reaction gas mixture in the catalyst loading is appropriate when from 0.5 to 20 seconds. The ratio disappear to who and to oxygen varies with the desired conversion and selectivity of the catalyst. It is advisable in the range from 0.5:1 to 40:1, in particular from 1:1 to 6:1, more preferably from 2:1 to 5:1. Typically, the propylene selectivity decreases with increasing conversion of propane. Therefore, preferably the reaction of propane to propylene is conducted in such a way that achieve relatively low conversions of propane at high selectively propylene. Particularly preferably, the conversion of propane is in the range from 5 to 40 mol%, often in the field from 10 to 30 mol%. The term "transformation of propane" means a portion of the added propane (the amount of propane contained in the pre-purified propane and, if necessary, return the circulating gas, which turns with the simple passage). Typically, the selectivity of the formation of propylene is from 50 to 98 mol%, more preferably from 80 to 98 mol%, moreover, the term "selectivity" means mol of propylene, which get turned mol of propane, expressed in molar percent.

Typically, the initial mixture used in the oxidative dehydrogenation of propane contains from 5 to 95 mol%. propane (per 100 mol%. the original mix). In addition to propane and oxygen, the initial mixture for heterogeneous catalyzed oxidisation may also include the following, in particular, inert components, that is their as carbon dioxide, carbon monoxide, nitrogen, noble gases, other hydrocarbons, such as side components contained in the crude propane and/or propylene. Heterogeneous oxidisation can also be carried out in the presence of diluents, such as, for example, water vapor.

Every any sequence of reactors can be used for carrying out a homogeneous oxidisation or heterogeneous catalyzed oxidisation propane, which is known to the person skilled in the art. Oxidisation can be, for example, in a single reactor or in a cascade of two or more reactors, between which, if necessary, introducing oxygen. There is also the opportunity to practice heterogeneous catalytic oxidisation in combination with each other.

Mainly propane dehydrogenation can be performed in the first reaction zone as well as heterogeneous catalytic dehydrogenation of propane at substantial exclusion of oxygen, as, for example, described in German patent application DE-A 3313573, international patent application WO 01/96270, German patent applications DE-A 10131297 or DE-A 10211275, or as specified below.

As heterogeneous catalytic dehydrogenation reaction takes place at the growth, transformation can be improved by lowering the partial pressure of the product. This is ostiguy simple way, for example, by dehydrogenation under reduced pressure and/or by blending in a mostly inert gas for dilution, such as, for example, water vapor, which is usually an inert gas for the reaction of dehydrogenation. The addition of water is preferred, you can also apply, in particular, in order to protect those parts of the reaction apparatus, which interact with a strongly reducing atmosphere (especially at high temperature), from the corrosive damage, for example, by "metal cleaning". Dilution with water causes as the next preference, as a rule, reducing coking of the used catalyst, as water vapor interacts with an educated coke on the principle of coal gasification. In addition, the water vapor can be used as a gas for dilution in the following, at least one zone for partial oxidation and/or ammonium oxidation in the environment (in this document as an abbreviation also, at least one partial area). But water vapor can be separated and also easy way to fully or partially from the mixture of products of dehydrogenation (for example, by condensing), which opens up the opportunity, the next time the application is received, thus modified, a mixture of products in at least one partial the tion zone to increase the gas for dilution N 2. Other diluents suitable for heterogeneous catalyzed propane dehydrogenation are, for example, CO, methane, ethane, CO2, nitrogen and noble gases such as No, Ne and ar. All of these diluents can be used, or for themselves, or in the form of various mixtures. It is advantageous that called thinners, as a rule, are diluents, suitable, at least one partial area. Basically, as already mentioned, in the respective reaction zone preferred inert diluents (this means to less than 5 wt. -%, preferably to less than 3% of the mass. and better yet, to less than 1% of the mass. chemically changing). In principle, heterogeneous catalyzed dehydrogenation of propane used all dehydrogenation catalysts known in the prior art. They can be roughly divided into 2 groups. Namely, those that are oxidative in nature (for example, chromium oxide and/or aluminum oxide), and those which consist of at least the selected one, as a rule, oxidizing media, as a rule, relatively noble metal (e.g. platinum).

In particular, this way you can apply all dehydrogenation catalysts, which are described in the international patent application WO 01/96270, European patent application EP-A 731077, German applications paten the DE-A 10211275, DE-A 10131297, international patent application WO 99/46039, U.S. patent 4788371, European patent application EP-A 705136, international patent application WO 99/29420, U.S. patent 4220091, U.S. patent 5430220, U.S. patent 5877369, European patent application EP-A 117148, German patent application DE-A 19937196, German patent application DE-A 19937105, as well as the German patent application DE-A 19937107. In particular, can be used as a catalyst according to example 1, example 2, example 3 and example 4 of German patent application DE-A 19937107.

And we are talking about the dehydrogenation catalysts which contain from 10 to 99.9% of the mass. zirconium dioxide, from 0 to 60% of the mass. aluminum oxide, silicon dioxide and/or titanium dioxide and from 0.1 to 10 wt. -%, at least one element of the first or second main group, the element of the third subgroup, the element of the eighth subgroup of the Periodic system of the elements, lanthanum and/or tin, provided that the sum of the percents is equal to 100% of the mass.

For carrying out heterogeneous catalyzed dehydrogenation of propane can be applied, in principle, all reactor types and variants of the methods known in the art. Description of these options methods include, for example, all relative to the dehydrogenation catalysts, as well as on proposed according to the invention the application of pre-purified propane reference documents technical is I.

A relatively detailed description according to the invention suitable ways dehydrogenation contains also "Catalytica® Studies Division, Oxidative Dehydrogenation and Alternative Dehydrogenation Processes, Study Number 4192OD, 1993, 430 Ferguson Drive, Mountain View, California, 94043-5272 USA.

Typical partial heterogeneous catalyzed dehydrogenation of propane is that it is endothermically. That is, the heat (energy)required to establish the desired reaction temperature, you can add or initial mixture of the reaction gases pre-and/or within a heterogeneous catalyzed dehydrogenation.

In addition, in particular for heterogeneous catalyzed degidrirovanii propane on the basis of the necessary high reaction temperatures normal is that in small quantities produces high boiling, high molecular weight organic compounds to carbon, which are allocated on the catalyst surface and the same is deactivated. To minimize this negative side effect, can be diluted with water vapor, the reaction gas mixture containing propane, conducted through the surface of the catalyst for heterogeneous catalyzed dehydrogenation at a higher temperature. Released carbon is partially or completely removed with these conditions by the principle of coal gasification

Another possibility to remove deposited carbon compounds is that from time to time through the dehydrogenation catalyst at a high temperature flowing a gas containing oxygen, and thus, so to speak, to burn off the deposited carbon. Therefore, but also and perhaps significant suppression of the formation of layers of carbon that from heterogeneous catalyzed to digidrirovannoe propane add molecular hydrogen before at a high temperature is conducted through the dehydrogenation catalyst.

Of course, it is also possible to add to from heterogeneous catalyzed to digidrirovannoe propane water vapor and molecular hydrogen in the mixture. Adding molecular hydrogen to the heterogeneous catalyzed the dehydrogenation of propane reduces unwanted education Allen (PROPADIENE), propene and acetylene as by-products.

Therefore, according to the invention may be appropriate, (so to speak) adiabatic conducting propane dehydrogenation (for example, with relatively minor conversion of propane). That is, the initial mixture of the reaction gases, as a rule, initially heated to a temperature from 500 to 700°C (comparatively from 550 to 650°C) (for example, by direct heating of the surrounding wall). In normal mode then it DOS is enough single adiabatic passage through the catalyst bed, to obtain the desired conversion, the mixture of the reaction gases are cooled to approximately 30°C to 200°C (depending on conversion and dilution). The presence of water vapor as the heat draws the attention when aspect adiabatic regime. Lower reaction temperature contributes to a longer service life of the used catalyst layer.

The principal is heterogeneous catalyzed dehydrogenation of propane with relatively minor conversion of propane, do o adiabatically or isothermal, carried out in a reactor with a fixed bed and in the reactor with a moving bed or fluidized bed.

To implement the proposed according to the invention method, it is notable that, in particular, in the adiabatic mode, just single reactor with the shaft furnace as a reactor with a fixed bed, through which axially and/or radially flowing the mixture of the reaction gases.

And in the most simple case we are talking about a single closed reaction volume, such as capacity, whose internal diameter is from 0.1 to 10 m, it is also possible from 0.5 to 5 m, and in which the fixed catalyst bed is applied to the support device (for example, the grate). The reaction volume, the loaded catalyst is m, which is insulated in the adiabatic regime, with axial flow round hot containing propane, the reaction gas. The geometry of the catalyst may be either spherical, or circular or in the form of Strakhov. As in this case, the reaction volume is performed via a very cost effective machine, are all preferred geometry catalysts, which have a particularly low pressure loss. This is primarily geometry catalysts that lead to large cavities or built-structured, such as monoliths or elements made in the form of cells. For the implementation of the radial flow of the reaction gas containing propane, the reactor may consist of, for example, two located in the outer shell, arranged concentrically one within another cylindrical grate and catalyst loading is in their annular gap. In the adiabatic case the outer shell, if necessary, again thermally insulate.

In the capacity of a catalyst for heterogeneous catalyzed propane dehydrogenation with comparatively low conversion of propane at a single pass is suitable, in particular, the catalysts described in the German patent application DE-A 19937107, first of all, for example, described.

After a long time of work what s the above-mentioned catalysts in a simple way, for example, you can restore using the fact that when the outlet temperature from 300 to 600°C., frequently at a temperature of from 400 to 550°C, beginning on the first stage of recovery the air (preferably) diluted with nitrogen and/or steam, is conducted through the catalyst bed. The load of the catalyst regenerating gas can be, for example, from 50 to 10000 h-1and the oxygen content of reducing gas from 0.5 to 20% vol.

The following further stages of recovery when otherwise equal conditions recovery as a reducing gas can be applied to the air. Technologically appropriate, it is recommended to wash the catalyst before it is recovered inert gas (for example, N2).

Then, as a rule, it is recommended to restore even when at rest is equal to the scheme of conditions of pure molecular hydrogen (hydrogen content should be ≥1% vol.) or molecular hydrogen diluted with an inert gas (preferably steam).

Heterogeneous catalyzed dehydrogenation of propane can be done with relatively low conversion of propane (≤30 mol%.) in all cases with equal loadings of catalyst (as the reaction gas in General and concerning the same that is contained propane), as at high conversion of propane (>30% mol.). This for Ruska the reaction gas may be, for example, from 100 to 10000 h-1often from 300 to 5000 h-1i.e. repeatedly from about 500 to 3000 h-1.

In particular, graceful way heterogeneous catalytic dehydrogenation of propane (especially at low conversion of propane) can be done in lattice reactor.

It contains spatial serial more than one layer of catalyst that catalyzes the dehydrogenation. The number of layers of catalyst may be from 1 to 20, suitable from 2 to 8, but also from 3 to 6. The catalyst layers are sequentially preferably radially or axially. Technologically appropriate in this lattice reactor used type of stationary catalyst layer.

In the simplest case, the fixed layers of catalyst in the reactor with the shaft furnace are axial or cylindrical grates are located in the annular gaps of the Central standing one to another. However, it is also possible to arrange the annular gaps in the segments one above the other, and the gas is conducted through a radial passage in the segment of the next overlying or underlying segment.

Expedient way the mixture of the reaction gases on its way from the catalyst bed to the next catalyst layer, for example, through translation over the edges of the heat exchanger heated by the hot gases, or through the Prov is giving through pipes, heated combustible gases, lattice reactor is subjected to the intermediate heat.

However, if the lattice, the reactor operates in the adiabatic regime, then this is sufficient for transformation of propane ≤30 wt. -%, in particular, when using the catalysts described in the German patent application DE-A 19937107, in particular, exemplary embodiments, the mixture of reaction gas lead to a reactor for dehydrogenation preheated at a temperature of from 450 to 550°C. and support within the lattice of the reactor at this temperature region. That is, the total propane dehydrogenation is carried out, therefore, when in the highest degree low temperatures, which is very favorable for the lifetime of the fixed layers of the catalyst between the two restorations.

Another is appropriate to carry out the catalytic autothermal dehydrogenation, i.e. for example, the above described intermediate is heated by direct (autothermal mode of action). To this mixture to the reaction gas limited add molecular oxygen or already before passing through the first catalyst layer and/or between the following layers of the catalyst. Depending on the dehydrogenation catalyst, thereby causing a limited combustion of hydrocarbons, soderjaschihsya mixture of the reaction gases (thus, also happens systematic partial oxidation With2-HC), if necessary, already on the catalyst surface deposited carbon or prepodobnykh compounds and/or hydrogen formed during the heterogeneous catalyzed propane dehydrogenation and/or added to the mixture of the reaction gases can also be technologically appropriate introduction to lattice reactor catalyst layers, which are loaded with catalyst which specifically (selectively) catalyzes the combustion of hydrogen and/or hydrocarbon) (as such catalysts are used, such as in documents U.S. patents 4788371, 4886928, 5430209, 5530171, 5527979 and 5563314; for example, such layers catalysts can to be placed in the lattice reactor alternative way to layers containing the catalyst). Released in this reaction heat, thus, to a certain extent autothermal way contributes nearly isothermal operation of heterogeneous catalyzed dehydrogenation of propane. When growing the selected processing time of the reaction gas in the catalyst bed may thus dehydrogenation of propane when falling or substantially constant temperature, which contributes to an especially long stage of time between the two restorations.

Generally, the above feeds the oxygen must be carried out so that the oxygen content of the reaction gas mixture, based on the contained amount of propane and propylene is from 0.5 to 30 wt%. At the same time as the oxygen source can be used as pure molecular oxygen or oxygen diluted with an inert gas, such as CO, CO2N2the noble gases, in particular, but also the air. The resulting gases of combustion are, as a rule, optionally diluted, and consequently contribute to heterogeneous catalyzed the dehydrogenation of propane.

Isotherm heterogeneous catalyzed dehydrogenation of propane can be improved further by the fact that in lattice reactor in the spaces between catalyst install closed before filling favorably, but not necessarily drained, the built-in elements (for example, in the form of tubes). These built-in elements can be placed in the corresponding layer of the catalyst. These embedded elements contain suitable solids or liquids that evaporate or melt above a certain temperature, and that consume heat and where the temperature is reduced, again condense and release heat.

The possibility of heating the initial mixture of a reactive gas for heterogeneous catalyzed dehydrogenation of propanda necessary reaction temperature is also what part of the contained propane and/or H2burn using molecular oxygen (for example, on suitable specific existing combustion catalysts, for example, by simple translation or transmission) and using the thus released heat of combustion contribute to heating to the desired reaction temperature (in this case, as a rule, is also partial oxidation With2-HC). The resulting products of combustion, such as CO2N2O, and also necessary for combustion with molecular oxygen, optionally associated with N2form a preferably inert gas for dilution.

Especially gracefully above the combustion of hydrogen is carried out, as described in German patent application DE-A 10211275. That is, in the method of continuous catalyzed partial dehydrogenation of propane in the gas phase, in which

in the reaction zone continuously served the reaction gas containing digidrirovanny propane,

- the reaction gas is carried out in a reaction zone through at least one fixed catalyst bed, which by the catalytic dehydrogenation is formed molecular hydrogen and at least partially propylene,

to the reaction gas before and/or after entry into the reaction zone add gas containing at least one molecule the hydrated oxygen

molecular oxygen in the reaction zone are oxidized by hydrogen contained in the reaction gas, partly to water vapor, and from the reaction zone, withdrawing the produced gas which contains molecular hydrogen, water vapor, propylene and propane,

which differs in that the gas produced is withdrawn from the reaction zone is divided into two partial quantities of identical composition and one of both partial quantities as circulating gas return to the reaction dehydrogenation zone, and another partial quantity according to the invention is again used as the gas mixture 1.

In principle, lattice reactor can also be a combination of heterogeneous catalyzed oxidative and classical dehydrogenation. For example, every second layer of the catalyst may be coated with a catalyst for oxidisation, and other layers of the catalyst - classic catalyst for dehydrogenation. Between the layers is an intermediate oxygen flow. Exothermic oxidisation in this case can be used an alternative to the combustion of hydrogen to heat the mixture of the reaction gases.

Following documents to the European patent application EP-A 117146, German patent application DE-A 3313573 and U.S. patent 3161670, you can apply the gas mixture 1 as a mixture to get the gas mixture 2. If necessary, you can also from the gas mixture 1 before using to obtain a gas mixture 2 from propane and propylene partially separate the various components. The latter may occur, for example, due to the fact that the gas mixture 1, if necessary, after it is pre-cooled in indirect Teploobmennik, conducted through the membrane, is formed, usually in the form of a pipe, which is exclusively permeable to molecular hydrogen. Thus, the separated molecular hydrogen can optionally be partially return in heterogeneous catalyzed degidrirovanie propane or add to other application. Partial or total amount of water vapor contained in the gas mixture 1, also can be separated from the gas mixture 1 before applying the gas mixture 1 for the gas mixture 2.

Alternatively, you can connect (for example, by simple transmission) is preferably cooled (preferably at temperatures from 10 to 70°C) gas mixture 1, for example, at a pressure of from 0.1 to 50 ATM and a temperature of 0 to 100°C, with a (preferably high-boiling organic solvent (preferably hydrophobic), in which preferably absorbed propane and propene. Thanks to the following desorption, rectification and/or Stripping gas, which is inert relative to the nutrient heterogeneous catalyzed partial oxidation in the gas phase and/or partial oxidation of ammonia to the environment and/or necessary in this reaction zone as a reagent (for example, air, propane and propene in the mixture in purified form and return it is used for receiving the gas mixture 2 (in the case of steam with air resulting gas mixture 1' may be identical gas mixture 2, that is, as such, can be applied directly to download the heterogeneous catalyzed partial oxidation in the gas phase and/or ammonium oxidation in the environment). Alternatively to the described phase separation through the absorption is also possible to apply a variable absorption under pressure or rectification under pressure. However, with the so-called stages of separation can also be associated exhaust With2. However, it can be significantly easier to observe on the basis of proposed according to the invention of the jet exhaust C2.

As the absorber for the above adsorption branch is suitable, in principle, all the sinks, which, primarily, are propane and propene. When the absorber it is preferably of an organic solvent, which preferably is hydrophobic and/or storable. Preferably the solvent has a boiling point (at normal pressure (1 ATM)at least 120°C, preferably at least 180°C., preferably from 200 to 350°C., in particular from 250 to 300°C., more preferably from 260 to 290°C. C is LeSabre flash point (at normal pressure (1 ATM) is above 110°C. Usually suitable as absorber are relatively non-polar organic solvents, such as, for example, aliphatic hydrocarbons, which preferably do not contain any valid outside the polar group, but also aromatic hydrocarbons. Usually it is desirable that the absorber has the highest possible boiling temperature at simultaneous high solubility of propane and propene. As absorbant as, for example, aliphatic hydrocarbons, such as alkanes having from 8 to 20 carbon atoms, or alkenes having from 8 to 20 carbon atoms, or aromatic hydrocarbons, such as middle oil fractions from the distillation of paraffin or ethers with voluminous (requiring steritest) groups on the atom, Oh, or mixtures thereof, and can be added to these polar solvents, such as 1,2-dimethylphthalate described in the German patent application DE-A 4308087. Also suitable are esters of benzoic acid and phthalic acid with alkanols containing straight chains containing from 1 to 8 carbon atoms, as a complex n-butyl ester of benzoic acid, methyl ester benzoic acid, complex ethyl ester of benzoic acid, a complex of dimethyl ester of phthalic acid, diethyl ether complex phthalic acid, and the so-called talones the existing oil, as diphenyl, simple diphenyl ether and mixtures of diphenyl and simple diphenyl ether or derivatives thereof chlorine and triarylamine, for example 4-methyl-4'-benzylethanolamine and its isomers 2-methyl-2'-benzyl-diphenyl-methane, 2-methyl-4'-benzylbiphenyl and 4-methyl-2'-benzyl-difenilmetana and mixtures of such isomers. Suitable absorber is a solvent mixture of diphenyl and simple diphenyl ether, preferably in the azeotropic composition, in particular from approximately 25% of the mass. of diphenyl (biphenyl) and approximately 75% of the mass. simple diphenyl ether, for example, commercially available Diphyl® (for example, firms Voeg Aktiengesellschaft). Often this solvent mixture contains a solvent, such as dimethylphthalate, in the amount of from 0.1 to 25 wt. -%, in the calculation of the whole mixture of solvents. Especially preferred solvents are also octane, nonanes, decanes, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane and octadecane, particularly suitable are, in particular, tetradecane. Is favorable, if applicable absorber, on the one hand, performs the above-mentioned boiling point, on the other hand, also does not have a very high molecular weight. The molecular mass of the absorber is preferably ≤300 g/mol. Also suitable are paraffin m is s'la, described in the German patent application DE-A 3313573 having from 8 to 6 carbon atoms. Suitable trade products are products sold by the company Haltermann, such as Halpasole i, as Halpasol 250/340 i and Halpasol 250/275 i, as well as oil printing inks under the names PKWF and Printosol. Preferred among the aromatic compounds are available commercial products, for example, type PKWFaf. The following are suitable trade products are n-paraffin (C13-C17or Mihagol®5 firms Erdöl-Raffinerie-Emsland GmbH, LIN-PAR®14-17 firm CONDEA Augusta S.p.A. (Italy) or SASOL Italy S.p.A., normal paraffin (heavy) C14-C18company SLOVNAFT in Slovakia.

Content (specified in the surface percentage of gas chromatographic analysis of the above products in a linear hydrocarbons is usually:

Sum9-C13: less than 1%; (C14: 30-40%; C15: 20-33%; C16: 18-26%; C17: up 18%;≥18: <2%.

The normal composition of the products of the company SASOL:

C13: 0.48 per cent; C14: 39,8%; C15: 20,8%; C16: 18,9%; C17: 17,3%, C18: 0,91%; C19:0,21%.

The normal composition of the products of the company Haltermann:

C13: 0,58%; C14: 33,4%; C15: 32,8%; C16: 25,5%; C17: 6,8%,≥18: <0.2 percent.

Conducting absorption is not subject to any special restrictions. You can use all the methods and conditions available to the person skilled in the art, as already described is whether the prior art, described in this document. Preferably, the gas mixture is mixed with the absorbent at a pressure of from 1 to 50 bar, preferably from 2 to 20 bar, more preferably from 5 to 10 bar and temperatures from 0 to 100°C., in particular from 30 to 50°C. the Absorbance can be conducted in the columns and shell and tube heat exchangers. You can work in a co-current or counter-current. Suitable columns for absorption are, for example, column trays (with cap plates and/or sieve plates), columns with structured packings (for example, tin packings with a specific surface of from 100 to 1000 or up to 750 m2/m3such as Mellapak® 250 Y) and Packed columns (for example, filled with tips process). But you can also use scrubbers and spray columns, absorbers with graphite block, surface absorbers, as thick-film and thin-film absorbers absorbers, as well as disc scrubbers, horizontal scrubbers with mechanical stirring and rotating scrubbers. In addition, it may be favorably the possibility of absorption in bubble columns with or without built-in elements.

The separation of propane and propene from the absorbent may occur by steaming, evaporating under reduced pressure (balloon) and/or distillation.

Department of disappear to the a and propene from the absorbent is preferably by evaporation and/or desorption. Desorption can occur in the usual way by changing the pressure and/or temperature, preferably at a pressure of from 0.1 to 10 bar, in particular from 1 to 5 bar, more preferably from 1 to 3 bar and a temperature of 0 to 200°C., in particular from 20 to 100°C., more preferably from 30 to 70°C., particularly preferably from 40 to 60°C. Gas suitable for steam is water vapor, however, are preferred in particular a mixture of oxygen, nitrogen, such as air. When using air or mixtures of oxygen/nitrogen, in which the oxygen content is more than 10 wt. -%, can be rationally add gas before or during the process of steaming, which reduces the area of the explosion. Particularly suitable for this is pre-purified propane. Especially suitable for steaming are distillation columns with or without built-in elements.

The separation of propane and propene from the absorbent can also occur by distillation or rectification, and you can apply available to the person skilled in the art columns with gaskets, fillers or relevant built-in elements. The preferred conditions for distillation or rectification are a pressure of from 0.01 to 5 bar, in particular from 0.1 to 4 bar, more preferably from 1 to 3 bar and the temperature (in the sump) from 50 to 300°C., in particular from 15 to 250°C.

Gas mixture 1'obtained by Stripping from the absorber, prior to its application to download at least one partial area can bring to even the next stage of the method, for example, to reduce the loss together otvarennogo absorber (for example, a branch in kapitbisig or deep filters) and thus also protect the at least one partial area of the absorber or to improve the separating action between a hydrocarbon having 3 carbon atoms, and other components. This separation of the absorber can occur at all stages of the method known to the person skilled in the art. The embodiment of such branch, preferred in the framework proposed in accordance with the invention a method is, for example, a sudden cooling water source stream from the device for steaming. In this case, the absorber is washed from such a loaded source of stream water and the original thread at a time is loaded with water. Such flushing or quenching can occur, for example, in the upper part of the distillation column above the plate, collecting the liquid through the backwash water or in its own device.

To maintain the effect of the separation in space for rapid cooling can install built-in items, increase the s surface to sudden cooling as known to the specialist rectification, removals and desorbtion.

In this respect, water is the preferred detergent because it usually does not interfere in the next heterogeneous catalyzed partial oxidation in the gas phase and/or the oxidation of ammonia to the environment. After the water washes away the absorber from the original thread, loaded with propane and propene, the mixture of water/absorber can lead to separation of the phases, and downloaded the original thread in favorable cases, as a gas mixture 1' = gas mixture 2 lead to heterogeneous catalyzed partial oxidation in the gas phase and/or the oxidation of ammonia to the environment.

How free 3 carbon atoms, otmerenny absorber, and the absorber is returned to the separation of the phases, you can re-apply for the purposes of the takeover.

In General, the gas mixture 1 and/or obtained from the same gas mixture 1' loaded with a gas mixture 2 can be applied in a known manner in at least one of the next reaction zone to download the heterogeneous catalyzed oxidation in the gas phase and/or ammonium oxidation in the environment of propene to obtain acrolein and/or acrylic acid and/or Acrylonitrile. At the same time as the oxidant to the gas mixture 1 and/or gas mixture 1', you can add pure molecular the initial oxygen air, air enriched with oxygen, or any other mixture of oxygen and inert gas. If partial oxidation talking about the conversion of propylene to propylene oxide, it is possible to do, as described in European patent application EP-A 372 972.

If we are talking about partial oxidation in an ammonia environment to Acrylonitrile, you can enter, for example, according to the German patent application DE-A 2351151. In the case of partial oxidation of propylene to acrolein and/or acrylic acid are suggested according to the invention method, composition of the gas mixture 2 with the General application of the gas mixture 1 and/or 1' (you can also use a mixture of both; that is, one part is not separated other) regulate, for example, in such a way that it performs the following molar ratios:

Propane:propene:N2:O2:H2O:other = from 0.5 to 20:1:0.1 to 40:0.1 to 10:0 to 20:0 to 1.

According to the invention is preferably the above-mentioned molar ratio is from 2 to 10:1:0.5 to 20:0.5 to 5:0.01 to 10:0 to 1.

Well, if the above-mentioned molar ratio according to the invention is from 3 to 6:1:1 to 10:1 to 3:0.1 to 2:0 to 0.5.

According to the invention are favorable gas mixture 2, which contain >0 to 30 wt. -%, often ≥ 0.5 to 25 wt. -%, repeatedly ≥ 1 to 20 wt. -%, often ≥ 3 to 15 wt. -%, it is advisable ≥ 5 to 10% of the mass. in Django pair, as such, the content of water vapor contributes according to the invention based on the exhaust C2. This is primarily the case if you use the following recommended system catalysts for heterogeneous catalyzed partial oxidation in the gas phase and/or ammonium oxidation in the environment (in particular, in the case of partial oxidation of propylene to acrolein and/or acrylic acid).

In particular, in combination with the above situation (but, in principle, in General) the proposed invention relates to proposed development proposed in accordance with the invention, a method in which pre-purified propane required for proposed according to the invention method, add directly to the first stage reaction is proposed according to the invention method.

But also the proposed invention also relates to preferred developments proposed according to the invention, a method in which pre-purified propane required for the method, the maximum partial (for example, only up to 75%, or only up to 50%, or only up to 25%) are added to the starting reaction gas mixture for the first reaction stage and, at least partially (as a rule, the residual quantity, if necessary, the total number) directly heterogeneous catalyzed casticin the th oxidation in the gas phase and/or ammonium oxidation in the environment (for example, the gas mixture 2).

Heterogeneous catalyzed partial oxidation in the gas phase and/or the oxidation of ammonia environment includes several reaction stages, so that each this reaction stage may occur directly flow (partial amount or the total number cleared propane) pre-purified propane.

Direct submission of pre-purified propane (for example, at least 25 wt. -%, or at least 50 wt. -%, or, at least 75 wt. -%, or 100% of the mass. total requirements proposed according to the invention method in a pre-cleaned propane) at least one reaction stage heterogeneous catalyzed partial oxidation in the gas phase and/or ammonium oxidation in the environment especially suited as a consequence according to the invention, an automatic release of the first reaction stage from2-HC. As a rule, it also reduces the risk of explosion.

As already mentioned above, heterogeneous catalyzed partial oxidation in the gas phase propylene to acrylic acid with molecular oxygen is, in principle, in two reaction stages, the following sequentially along the reaction coordinate, of which the first results acrolein and the other from crole is on to acrylic acid.

This over reaction on two time following stages sequentially in a known manner opens the possibility to interrupt proposed according to the invention the method at the stage of acrolein (stage predominant formation of acrolein) and to carry out the separation of the target product at this stage, or is proposed according to the invention the method continues to the predominant formation of acrylic acid and only then carry out the separation of the target product.

If a proposed according to the invention, the method leads to the predominant formation of acrylic acid according to the invention is preferably a process in two stages, that is, two consecutive stages of oxidation, but it is desirable for each of the two stages of oxidation used fixed bed of catalyst and preferably also other reaction conditions, such as, for example, the temperature of the fixed catalyst layer, more favorably aligned in relation to the proposed invention.

Although according to the invention is particularly suitable catalysts for the first stage of oxidation (propylene→acrolein) as the active mass of the oxides multimetallic containing the elements Mo, Fe, Bi, to a certain extent also catalyze the second stage of oxidation (acrolein→acrylic is the first acid), yet for the second stage of oxidation according to the invention the preferred catalysts whose active material is at least one oxide multimetallic containing the elements Mo and V. the Above and all following as according to the invention is favorable described active mass of oxides of multimetallic differ in that they contribute according to the invention relative to the exhaust C2especially pronounced way.

Thus, the method of heterogeneous catalyzed partial oxidation of propylene on layers of catalysts (e.g., fluidized layer or the fixed layer whose catalysts as active masses have at least one oxide multimetall containing the elements Mo, Fe and Bi, is suitable, in particular, as suggested according to the invention one method for obtaining acrolein (and, if necessary, acrylic acid) or as the first reaction stage for proposed according to the invention the two-stage obtain acrylic acid.

While the implementation of single-stage heterogeneous catalyzed partial oxidation of propylene to acrolein, and optionally acrylic acid or the two-stage heterogeneous catalyzed partial oxidation of propylene to acrylic acid when n is izlozenom according to the invention using the gas mixture 2 can be in particular, as described in European patent application EP-A 700714 (first reaction stage; as there describe, but also in the corresponding counter-current procedure in the salt bath and the mixture of the reaction gases through a shell and tube reactor), European patent application EP-A 700893 (second reaction stage; as there describe, but also in the corresponding counter-current way of doing things), international patent application WO 04/085369 (in particular, this document is considered as a single component of this document) (as a two-stage method), the international application patent WO 04/85363, German patent application DE-A 10313212 (first reaction stage), European patent application EP-A 1159248 (as a two-stage method), European patent application EP-A 1159246 (second reaction stage), European patent application EP-A 1159247 (as a two-stage method), German patent application DE-A 19948248 (as a two-stage method), German patent application DE-A 10101695 (single-stage or two-stage), the international patent application WO 04/085368 ( as the two-stage method), German patent application DE-A 102004021764 (two-stage), the international patent application WO 04/085362 (first reaction stage), the international patent application WO 04/085370 (second reaction stage), the international patent application WO 04085365 (second reaction stage), international patent application WO 04/085367 (two-stage), European patent applications EP-A 990636, EP-A 1007007 and EP-A 1106598.

This applies to all embodiments contained in these documents. They can be carried out, as described in these documents, but with the difference that as a starting reaction gas mixture for the first reaction stage (from propylene to acrolein) proposed use according to the invention the gas mixture 2. Concerning the other parameters, proceed as in the examples of implementation of these documents (in particular, relative to the fixed layers of the catalyst and load reagents fixed catalyst). If in the above-mentioned embodiments of the prior art do the two-stage and between the two reaction stages is filing secondary oxygen (secondary air), so if it is the appropriate method, adapted to their number, however, in the sense that the molar ratio of molecular oxygen to acrolein loaded in the gas mixture of the second reaction stage corresponds to the documents mentioned in the examples of implementation.

For the corresponding reaction stages, particularly suitable catalysts of the oxide multimetallic repeatedly described and fully known to the specialist in this region the STI. For example, in European patent application EP-A 253409 on page 5 refer to the corresponding U.S. patent.

According to the invention is favorable catalysts for the respective stages of oxidation describe also in the German patent applications DE-A 4431957, DE-A 102004025445 and DE-A 4431949. It really is, in particular, to the General formula I in both of the above documents. According to the invention particularly preferred catalysts for the appropriate stage of the oxidation describe in documents of German patent applications DE-A 10325488, DE-A 10325487, DE-A 10353954, DE-A 10344149, DE-A 10351269, DE-A 10350812 and DE-A 10350822.

For proposed according to the invention the reaction of heterogeneous catalyzed partial oxidation in the gas phase propylene to acrolein or acrylic acid or mixtures thereof are used, as already mentioned, as the active mass, in principle, all the mass of the oxides multimetallic containing Mo, Bi and Fe.

They are, in particular, the active mass of oxides multimetallic General formula I of the German patent application DE-A 19955176, active mass of oxides multimetallic General formula I of the German patent application DE-A 19948523, active mass of oxides multimetallic General formulas I, II and III of the German patent application DE-A 10101695, active mass of oxides multimetallic General formulas I, II and III of the German patent application DE-A 19948248 and active mass of the oxides multimetall is in General formula I, II and III of the German patent application DE-A 19955168 and active mass of oxides multimetallic named in European patent application EP-A.

Also suitable for this stage of the reaction are the catalysts of the oxide multimetallic containing Mo, Bi and Fe, which are described in the German patent applications DE-A 10046957, DE-A 10063162, DE-C 3338380, DE-A 19902562, European patent application EP-A 015565, German patent application DE-C 2380765, European patent applications EP-A 807465, EP-A 279374, German patent application DE-A 3300044, European patent application EP-A 575897, U.S. patent 4438217, German patent application DE-A 19855913, international patent application WO 98/24746, German patent application DE-A 19746210 (those of General formula (II), Japanese patent application JP-A 91/294239, European patent applications EP-A 293224 and EP-A 700714. It really is, in particular, for the exemplary embodiments in these documents, among which according to the invention particularly preferred are the European patent application EP-A 015565, EP-A 575897, German patent application DE-A 19746210 and DE-A 19855913. Especially underlined in this regard are the catalyst according to example 1C from European patent application EP-A 015565, and the catalyst obtained in an appropriate way, whose active mass, however, has a composition Mo12Ni6,5Zn2Fe2Bi1P0,0065K0,06Ox·1SiO 2. In addition, emphasize the example with the current No. 3 of the German patent application DE-A 19855913 (stoichiometry: Mo12Co7Fe3Bifor 0.6To0,08Si1,6Aboutx) as a solid catalyst with a hollow cylinder geometry 5 mm × 3 mm × 2 mm (external diameter × height × internal diameter)and a solid catalyst oxide multimetallic II according to example 1 of German patent application DE-A 19746210. Also referred to as the catalyst of oxides multimetallic of U.S. patent 4438217. The last really, in particular, if the hollow cylinder has the geometry of 5.5 mm × 3 mm × 3.5 mm, or 5 mm × 2 mm × 2 mm, or 5 mm × 3 mm × 2 mm, or 6 mm × 3 mm × 3 mm, or 7 mm × 3 mm × 4 mm (external diameter × height × internal diameter). The following possible geometry catalysts are in this respect strangle (for example, 7.7 mm in length and 7 mm in diameter; or 6.4 mm in length and 5.7 mm in diameter).

A large number of active mass of oxides multimetallic suitable for the stage from propylene to acrolein and, if necessary, acrylic acid, is carried under the General formula IV

in which the variables have the following meanings:

X1= Nickel and/or cobalt,

X2= thallium, an alkali metal and/or alkaline earth metal,

X3= zinc, phosphorus, arsenic, boron, antimony, tin, CERI is, lead and/or tungsten,

X4= silicon, aluminum, titanium and/or zirconium,

a = from 0.5 to 5,

b = from 0.01 to 5, preferably from 2 to 4

C = from 0 to 10, preferably from 3 to 10,

d = from 0 to 2, preferably from 0.02 to 2,

e = from 0 to 8, preferably from 0 to 5,

f = from 0 to 10 and

n = number, which is set through the valence and a lot different from the oxygen elements in the IV.

Get them in a known manner (see, for example, German patent application DE-A 4023239) and usually in the form of the substance to receive the balls, rings or cylinders or used in the form of a shell catalyst, i.e. molded inert carriers coated active mass. But of course, they can also be used in powder form as catalysts.

Suitable geometries of solid catalysts are, for example, a solid cylinder or a hollow cylinder with an external diameter and a length of from 2 to 10 mm In the case of the hollow cylinder is suitable wall thickness 1 to 3 mm of Course, the solid catalyst also has a spherical geometry, the diameter of the balls can vary from 2 to 10 mm

Particularly favorable geometry of the hollow cylinder is 5 mm × 3 mm × 2 mm (external diameter × length × internal diameter), in particular in the case of solid catalysts.

Of course, the formation of powdery active the mass or powder, not yet and/or partially calcined prior to masses also occur by coating formed on an inert catalyst carrier. The coating media to produce a shell catalysts, as a rule, is carried out in a suitable rotatable container, as is known from German patent application DE-A 2909671, European patent applications EP-A 293859 or EP-A 714700. Suitable for coating medium applied powder mass moisturize and after application, for example, with hot air, then dried. The thickness of the layer of powdered material is applied to the carrier, choose the appropriate in the field, lying from 10 to 1000 μm, preferably in the range from 50 to 500 μm and particularly preferably in the range from 150 to 250 microns.

As materials of media use may be made of conventional porous or nonporous aluminum oxide, silicon dioxide, thorium dioxide, zirconium dioxide, silicon carbide or silicates such as magnesium silicate or aluminum silicate. They behave, as a rule, mostly inert relative to the target reaction subordinated proposed according to the invention method. The media can be molded regularly or not regularly and systematically preferred molded media obviously formed by the surface roughness, for example balls or hollow cylinder. Approaching them is the use of mostly non-porous, with a rough surface, spherical media of steatite, whose diameter is from 1 to 10 mm or 8 mm, preferably from 4 to 5 mm. But also suitable is the use of cylinders as carriers whose length is from 2 to 10 mm and whose external diameter is from 4 to 10 mm, hence in the case of proposed according to the invention suitable rings as media wall thickness is usually from 1 to 4 mm, According to the invention preferably applied annular carriers have a length of from 2 to 6 mm, an external diameter of from 4 to 8 m and wall thickness from 1 to 2 mm According to the invention are primarily suitable as carriers are also rings of geometry 7 mm × 3 mm × 4 mm (external diameter × length × internal diameter). The dispersion of the catalytically active oxide mass deposited on the surface of the carrier, of course, consistent with the desired shell thickness (compare European patent application EP-A 714700).

For the stage from propylene to acrolein (and, if necessary, acrylic acid) according to the invention is preferably applied to the active mass of oxides multimetallic are, in addition, the masses of the General formula V

in which the variables have the following meaning:

Y1= only bismuth or bismuth and at least one element of t is llur, antimony, tin and copper,

Y2= molybdenum or molybdenum and tungsten,

Y3= alkali metal, thallium and/or samarium,

Y4= alkaline earth metal, Nickel, cobalt, copper, manganese, zinc, tin, cadmium and/or mercury,

Y5= iron or iron and at least one of the elements chromium or cerium,

Y6= phosphorus, arsenic, boron and/or antimony,

Y7= rare earth metals, titanium, zirconium, niobium, tantalum, rhenium, ruthenium, rhodium, silver, gold, aluminum, gallium, indium, silicon, germanium, lead, thorium and/or uranium,

a' = from 0.1 to 8,

b' = from 0.1 to 30,

with' = from 0 to 4,

d' = from 0 to 20,

e' > from 0 to 20,

f' = from 0 to 6,

g' = from 0 to 15,

h' = 8 to 16,

x', y' = numbers which are determined through the valence and a lot different from the oxygen elements in V and

p, q = numbers whose ratio p/q is from 0.1 to 10,

containing in three dimensions, from their local environment on the basis of their composition differing from their local environment, the limited field of chemical composition Y1a, Y2bOx'whose maximum diameter (longest through the center of gravity of the region going direct segment connecting two points located on the surface (boundary surface) of the region) is from 1 nm to 100 μm, frequently from 10 nm to 500 nm or from 1 μm to 50 or 25 μm.

Especially before occhialini proposed according to the invention the mass of the oxides multimetallic V are such in which Y1is only bismuth.

Among them preferred are those which correspond to the General formula VI

in which the variables have the following meanings:

Z2= molybdenum or molybdenum and tungsten,

Z3= Nickel and/or cobalt,

Z4= thallium, an alkali metal and/or alkaline earth metal,

Z5= phosphorus, arsenic, boron, antimony, tin, cerium and/or lead,

Z6= silicon, aluminum, titanium and/or zirconium,

Z7= copper, silver and/or gold,

and" = 0.1 to 1,

b" = from 0.2 to 2,

with" = 3 to 10,

d = from 0.02 to 2,

e" > from 0.01 to 5, preferably from 0.1 to 3,

f = from 0 to 5,

g = from 0 to 10,

h = from 0 to 1,

x", y" = numbers which are determined through the valence and a lot different from the oxygen elements in VI and

p", q" = numbers whose ratio p/q is from 0.1 to 5, preferably from 0.5 to 2,

moreover, in highly preferred those mass VI, in which Z2b=(tungsten)band Z212=(molybdenum)12.

In addition, preferably, if at least 25% of the mass. (preferably at least 50 wt%. and especially preferably at least 100% of the mass.) General part [Y1a'Y2b'Ox']p([BiaZ2bOx"]p) the agreement is but the invention of suitable mass of oxides multimetallic V (mass of oxides multimetallic VI) according to the invention suitable mass of oxides multimetallic V (mass of oxides multimetallic VI) present in the form of three-dimensional measurements from their local environment on the basis of their composition differing from their local environment, the limited field of chemical composition Y1a'Y2b'Ox'[BiaZ2bOx"]whose maximum diameter is in the range from 1 nm to 100 μm.

Regarding the formation relative to the catalysts of the mass of oxides multimetallic V, really said for catalysts of the mass of oxides multimetallic IV.

The active mass of the mass of oxides multimetallic V describe, for example, in European patent application EP-A 575897, as well as in the German patent application DE-A 19855913.

The above featured inert materials, media can also be used, including as inert materials for dilution and/or separation of the respective fixed layers of catalysts or as their protecting and/or gas mixture heating load.

At this point mention that all the catalysts and the mass of the oxides multimetallic, which according to the invention is recommended as suitable for the stage from propane to acrolein, in principle, also suitable for partial oxidation in an ammonia environment of propylene to Acrylonitrile.

For the second stage (second reaction stage) heterogeneous catalyzed partial oxidation in the gas phase of acrolein what about the acrylic acid according to the invention as the active mass is applied preferably as already mentioned, in principle, all the mass of the oxides multimetallic containing Mo and V to the required catalysts, for example, from German patent application DE-A 10046928.

A large number of them, for instance from German patent application DE-A 19815281, we can summarize the General formula VII

in which the variables have the following meanings:

X1= W, Nb, TA, CR and/or CE,

X2= Cu, Ni, Co, Fe, Mn and/or Zn,

X3= Sb and/or Bi,

X4= one or more alkali metals,

X5= one or more alkaline earth metals

X6= Si, Al, Ti and/or Zr,

a = 1 to 6,

b = from 0.02 to 4

from = from 0.5 to 18,

d = from 0 to 40,

e = from 0 to 2,

f = from 0 to 4,

g = from 0 to 40 and

n = number, which is set through the valence and a lot different from the oxygen elements in VII.

According to the invention preferred embodiments of within the active oxide multimetallic VII are those covered by the following values of the variables of the General formula VII:

X1= W, Nb and/or CR,

X2= Cu, Ni, Co and/or Fe,

X3= Sb,

X4= Na and/or K,

X5= CA, Sr and/or BA,

X6= Si, Al and/or Ti,

a = from 1.5 to 5,

b = 0.5 to 2,

with a = 0.5 to 3,

d = from 0 to 2,

e = from 0 to 0.2,

f = from 0 to 1, and

n = the number that is determined through the valence and the many different the t oxygen elements in VII.

According to the invention in a highly preferred oxides multimetallic VII are, however, those of General formula VIII

where

Y1= W and/or Nb,

Y2= Cu and/or Ni,

Y3= CA and/or Sr,

Y4= Si and/or Al,

a' = 2 to 4,

b' = from 1 to 1.5,

with' = 1 to 3,

f' = from 0 to 0.5,

g' = from 0 to 8, and

n' = number, which is set through the valence and a lot different from the oxygen elements in VIII.

According to the invention suitable active mass of oxides multimetallic (VII) are obtained by a known method described, for example, in German patent application DE-A 4335973 or in European patent application EP-A 714700.

In principle, the active mass of oxides multimetallic suitable for the reaction of partial oxidation "acrolein→acrylic acid", in particular the following General formula VII can be obtained in a simple way (as active material suitable for the first stage partial oxidation) by the fact that from suitable sources of their elemental constituents receive opportunities dense, preferably finely minced, prepared according to their stoichiometry dry mixture and its calicivirus at temperatures from 350 to 600°C. the Calcification can be conducted under an inert gas and an oxidizing atmosphere, such as, for example, the air (a mixture of nechego gas and oxygen), and in a reducing atmosphere (for example, a mixture of inert gas and reducing gases such as H2, NH3, CO, methane and/or acrolein or the named gases from the regenerating for action). The duration of calcination can vary from several minutes to several hours and usually decreases with temperature. As sources for the elemental constituents of the active mass of oxides multimetallic VII apply such compounds, in which we are talking about the oxides and/or of such compounds, which are converted into oxides by heating, at least in the presence of oxygen.

Intensive mixing of the starting compounds to obtain the mass of oxides multimetallic VII may occur in dry or in wet form. It occurs in dry form as the parent compound expediently used in the form of a fine powder, and after mixing and, if necessary, subjected to thickening of calcification. Preferably the wet mixing occurs, however, in wet form.

Usually the parent compound are mixed with each other in the form of an aqueous solution and/or suspension. Especially dense dry mixture obtained when the described method is mixing if emanate solely from being in dissolved form springs elementary with the other commercial. The solvent preferably used water. Then, the resulting water mass is dried, and the drying process takes place preferably by spray drying the aqueous mixture with the temperature at the outlet from 100 to 150°C.

The resulting mass of oxides multimetallic, in particular those of the General formula VII, can be used for oxidation of acrolein formed as in the form of powder, and to a certain geometry catalysts, and the shaping may occur before or after the final calcination. For example, of the active mass in the form of powder or not calcined prior mass through evaporation to the desired geometry catalysts (e.g., by tabletting, extrusion or extrusion), it is possible to obtain a solid catalyst, in this case, if necessary, you can add auxiliary means, such as, for example, graphite or stearic acid as an external lubricant and/or supporting means for the form, and reinforcing agents, such as microfibers of glass, asbestos, silicon carbide or potassium titanate. Suitable geometries of solid catalysts are, for example, solid cylinders or hollow cylinders having an external diameter and a length of from 2 to 10 mm In the case of the hollow cylinder is suitable wall thickness 1 to 3 mm of Course, the whole cat is the lyst may also have spherical geometry, the diameter of the balls can vary from 2 to 10 mm (e.g., 8.2 mm or 5.1 mm).

Of course, forming a powder of the active mass or powder, have not calcined, of an earlier mass can also occur by coating on a molded inert catalyst carrier. The coating media to produce a shell catalysts, as a rule, is carried out in a suitable rotatable container, as, for example, known from German patent application DE-A 2909671, European patent applications EP-A 293859 or from EP-A 714700.

It is advisable applied powder mass to cover media moisturize and after application, for example using hot air again dried. The thickness of the layers of powdered material is applied to the medium, it is advisable to choose lying in the range from 10 to 1000 μm, preferably in the range from 50 to 500 μm and particularly preferably in the range from 150 to 250 microns.

The materials of the media, you can apply the usual porous or nonporous aluminum oxide, silicon dioxide, thorium dioxide, zirconium dioxide, silicon carbide or silicates such as magnesium silicate or aluminum. The media can be molded regularly or not regularly and systematically preferred molded media obviously formed by the surface roughness, for example the ball is or hollow cylinder with a substrate of fine gravel. Suitable is the use of mostly non-porous, rough surface, spherical media of steatite, whose diameter is from 1 to 10 mm or 8 mm, preferably from 4 to 5 mm That is suitable spherical geometry can have a diameter of 8.2 mm and 5.1 mm, But also suitable as carriers is the use of cylinders whose length is from 2 to 10 mm and whose external diameter is from 4 to 10 mm In the case of proposed according to the invention suitable rings as media wall thickness is on this basis usually from 1 to 4 mm. Preferably applied annular carriers have a length of from 2 to 6 mm, an external diameter of from 4 to 8 m and a wall thickness of from 1 to 2 mm According to the invention, especially suitable as carriers are also rings of geometry 7 mm × 3 mm × 4 mm (external diameter × length × internal diameter). The dispersion of the catalytically active oxide mass deposited on the surface of the carrier, of course, consistent with the desired shell thickness (compare European patent application EP-A 714700).

Favorable for the reaction "acrolein→acrylic acid" used by the active mass of oxides multimetallic are, in addition, mass General formula IX

in which the variables have the following meanings:

D = Mo12Va' Z1bZ2c"Z3dZ4eZ5fZ6gOx",

E = Z712CuhHjOy,

Z1= W, Nb, TA, CR and/or CE,

Z2= Cu, Ni, Co, Fe, Mn and/or Zn,

Z3= Sb and/or Bi,

Z4= Li, Na, K, Rb, Cs and/or N,

Z5= Mg, Ca, Sr and/or BA,

X6= Si, Al, Ti and/or Zr,

X7= Mo, W, V, Nb and/or TA, preferably Mo and/or W,

a" = from 1 to 8

b" = 0, 2 to 5,

with" = 0 to 23

d = from 0 to 50,

e = from 0 to 2,

f = from 0 to 5,

g = from 0 to 50,

h" = 4 to 30,

l" = from 0 to 20 and

x", y" = numbers which are determined through the valence and a lot different from the oxygen elements in IX and

p, q = numbers other than zero whose ratio p/q is from 160:1 to 1:1,

and get through that mass of oxides multimetallic E

separated prepare in micronized form (initial weight of 1) and then prepared by solid source mass 1 in aqueous solution, aqueous suspension or in finely ground dry mixture of sources of the elements Mo, V, Z1, Z2, Z3, Z4, Z5, Z6which contain the abovementioned elements in the stoichiometry D

(original mix 2), enter in the desired quantitative ratio p:q, if necessary the tis the resulting aqueous mixture is dried, and thus this dry prior to mass calicivirus before or after drying to the desired geometry of the catalyst at temperatures of from 250 to 600°C.

Preferred are the mass of the oxides multimetallic IX, in which the introduction prepared by solid source mass 1 in the water source mass 2 occurs at a temperature of <70°C. a Detailed description of the preparation of catalysts of the mass of oxides multimetallic VI contain, for example, European patent application EP-A 668104, German patent application DE-A 19736105, DE-A 10046928, DE-A 19740493 and DE-19528646.

Regarding the formation relative to the catalysts of the mass of oxides multimetallic IX really said for catalysts of the mass of oxides multimetallic VII.

For the stage "acrolein→acrylic acid" is exclusively suitable catalysts oxides multimetallic are also those of the German patent application DE-A 19815281, in particular with the active mass of oxides multimetallic General formula I of this document.

For the stage from propylene to acrolein preferably used ring solid catalyst and for the stage from acrolein to acrylic acid - rings of shell catalyst.

Conduct proposed according to the invention method, from propylene to acrolein (and, if necessary, acrylic acid), can occur is arranged with the described catalysts, for example, in a reactor with a fixed layer having a single zone and multi-pipe, as described in the German patent application DE-A 4431957. When this gas mixture 2 and the coolant (heat exchange medium) can be performed in a co-current or countercurrent, watching through the reactor.

The reaction pressure is usually in the range from 1 to 3 bar and the loading shared space fixed catalyst layer (source) of the reaction gas mixture 2 is preferably from 1500 to 4000 or 6000 Nl/l·h or more. Load propylene (download propylene fixed catalyst layer) is usually from 90 to 200 Nl/l·h, or up to 300 Nl/l·h or more. According to the invention particularly preferred load propylene above 120, or 130, or 135 Nl/l·h or ≥140 Nl/l·h, or ≥150 Nl/l·h or ≥160 Nl/l·h, because a high load of propylene cause elevated point of overheating and thus increased partial oxidation With2-HC (all the above are valid regardless of the special choice of the reactor with a fixed bed).

Preferably the reactor with a porous layer having a single zone and multi-pipe, loaded with a gas mixture flows from the top. As the heat exchange means, it is advisable to apply a salt melt, preferably consisting of 60% of the mass. potassium nitrate (KPO3and 40% of the mass. neither is Rita sodium (NaNO 2), or 53% of the mass. potassium nitrate (KPO3), 40% sodium nitrite (NaNO2and 7% of the mass. sodium nitrate (NaNO3).

Through the reactor can be observed, as already mentioned, as the salt melt and reaction gas mixture 2 is conducted in the co-current and counter-current. Salt melts carried out preferably in a winding form around the contact tubes.

If you contact the pipes run from the top down, it is advisable to download the contact tube catalyst from the bottom up (for inflow of bottom-up boot sequence expedient manner overturn):

first length from 40 to 80 or 60% of the length of the contact tube or catalysts, or a mixture of catalyst and inert material, the latter, based on the mixture, is mass fraction of up to 20% of the mass. (segment);

is it then at length from 20 to 50 or up to 40% of the mass. the total length of the pipe or only a catalyst, or a mixture of catalyst and inert material, the latter, based on the mixture, is mass fraction of up to 40% of the mass. (cut In); and

- then at length from 10 to 20% of the total length of the pipe the filling of inert material (segment a), which preferably is chosen so that it is possible negligible pressure loss.

Preferably a segment is undiluted.

The above options download the appropriate key, in particular, in the case when the catalysts are used such according to example 1 of German patent application DE-A 10046957 or according to example 3 of German patent application DE-A 10046957 and as inert material steatite rings of geometry 7 mm × 7 mm × 4 mm (external diameter × height × internal diameter). Relative temperature salt baths really said in the German patent application DE-A 4431957.

Conduct proposed according to the invention, partial oxidation, from propylene to acrolein (and, if necessary, acrylic acid), can occur with the described catalysts, for example, in a reactor with a fixed bed with two zones and multi-pipe, as described in the German patent application DE-A 19910506 or in European patent application EP-A 1106598. In both the above cases (and in General with proposed according to the invention the method, the achieved conversion of propene with a simple pass is usually at values ≥90% wt., or ≥95% of the mass. and selectivity of the formation of acrolein at values ≥90% of the mass. According to the invention preferably is proposed according to the invention the partial oxidation of propene to acrolein or acrylic acid or mixtures thereof is as described in European patent application EP-A 1159244 and highly preferably as in the international patent application WO 04/085363, as well as in the international patent application WO 04/085362, but with the difference that as a starting reaction gas mixture used is proposed according to the invention the gas mixture 2. In particular, all examples of the implementation of these documents can be conducted as described in these documents, however, when applying the gas mixture 2 as downloadable gas mixture. In particular, when using gas mixtures 2, described in this document as especially preferred, as examples.

The documents of the European patent application EP-A 1159244, international patent application WO 04/085363 and WO 04/085362 considered as a single component of this document.

The preferred implementation is proposed according to the invention the partial oxidation of propylene to acrolein, or acrylic acid, or their mixtures is proposed according to the invention by a method in which the gas mixture is conducted through the filling of the catalyst fixed bed whose active material is at least one oxide multimetall containing the elements Mo, Fe and Bi, provided that

- filling the fixed catalyst layer come in two spatially successive temperature zones a, b,

as the temperature of temperature zone a and the temperature of temperature zone b is a is a temperature in the range from 290 to 380°C,

- download the fixed catalyst layer consists of at least two spatially one behind the other in the following areas loading of the catalyst fixed bed, and the specific volume activity within the zone loading of the catalyst fixed bed is basically constant and increases in the direction of flow of the gas mixture 2 in the transition from the loading zone of the catalyst fixed bed to another loading area of the catalyst fixed bed (suitable abruptly),

- temperature zone And continues until the conversion of propene from 40 to 80 wt. -%,

- in a single passage of the gas mixture 2 through the common load of the catalyst fixed bed conversion of propene is ≥90% of the mass. and selectivity of the formation of acrolein is ≥90% of the mass, calculated on converted propene,

- the temporal sequence in which the gas mixture 2 flows through temperature zones a, b, corresponds to the alphabetic sequence of temperature zones,

- load loading of the catalyst with a porous layer of the propene contained in the gas mixture 2 is ≥90 Nl of propene/l loading of the catalyst fixed bed·h, and

- the difference between the Tmax-Tmaxvformed from the maximum temperature Tmaxthat is, the gas mixture 2 within the temperature the nuclear biological chemical (NBC zone And, and maximum temperature Tmaxvthat is, the gas mixture 2 within the temperature zone is ≥0°C,

and which preferably additionally differs in that the transition from temperature zone a to temperature zone In the catalyst loading with a fixed layer does not coincide with the transition from the loading zone of the catalyst fixed bed to another loading area of the catalyst fixed bed.

More detailed data for this image are in the international patent application WO 04/085362, which is a single component of this document, and following the completion of this document when describing a particularly preferred two-stage partial oxidation of propylene to acrylic acid.

The second stage in the case of the two-stage partial oxidation from propylene to acrolein, namely partial oxidation from acrolein to acrylic acid can occur with the described catalysts, for example, in a reactor with a fixed layer having a single zone and multi-pipe, as described in the German patent application DE-A 4431949. The mixture of reaction gas and the coolant can pass under observation through the reactor in cocurrent flows. Typically, a mixture gas obtained according to the preceding invention, the partial oxidation impregnated the Jena to acrolein, in principle, conduct such as (optionally followed after intermediate cooling (this may occur directly or indirectly through, for example, the additive secondary air)), i.e. without separation of the side components, in the second stage of the reaction, i.e. partial oxidation of acrolein.

Molecular oxygen is required for the second stage partial oxidation of acrolein, (and) may already be contained in the gas mixture 2 to be proposed according to the invention the partial oxidation of propylene to acrolein. But it is also possible to directly add partially or completely to a mixture gas obtained in the first stage of reaction, it is proposed according to the invention the partial oxidation of propylene to acrolein (this preferably is in the form of (secondary) air, but can also occur in the form of pure oxygen or mixtures of inert gas or oxygen). Regardless of how come loaded gas mixture such partial oxidation of acrolein to acrylic acid preferably has the following contents:

From 4.5 to 8% of the mass.acrolein,
From 2.25 or 4.5 to 9% of the mass.molecular oxygen
From 6 to 30% of the mass.propane,
From 32 to 72% of the mass.molecular nitrogen and
From 5 to 15% of the mass. or up to 30% of the mass.water vapour.

The above downloadable gas mixture preferably has the following contents:

From 5.5 to 8% of the mass.acrolein,
From a 2.75 or 5.5 to 9% of the mass.molecular oxygen
From 10 to 25% of the mass.propane,
From 40 to 70% of the mass.molecular nitrogen and
From 5 to 15% of the mass.water vapour.

The above downloadable gas mixture in the highest degree preferably has the following contents:

From 6 to 8% of the mass.acrolein (preferably from 6 to 7 wt. -%),
3 or 6 to 9% of the mass.molecular oxygen
From 10 to 20 wt. -%is Rapana (preferably from 10 to 16 wt. -%),
From 50 to 65% of the mass.molecular nitrogen and
From 7 to 13% of the mass.water vapour.

preferably the field is valid independently from each other, however, preferably carried out simultaneously.

In addition to the above-mentioned loaded gas mixtures preferably, if the molar ratio of V4molecular oxygen contained in the download of the gas mixture, to acrolein contained in the downloadable mixture is ≥0.5 and ≤2, preferably ≥1 and ≤1,75, particularly preferably ≥1 and ≤1.5 and highly preferably ≥1 and ≤1,25.

In addition to the above-mentioned loaded gas mixtures is preferably, if the molar ratio of V5propane contained in the download of the gas mixture, for in it is contained acrolein is from 1 to 4, mainly from 1.5 to 3.5, particularly preferably from 1.5 to 3 and highly preferably from 1.5 or 2 to 2.5.

As in the first stage reaction and the second reaction stage, the reaction pressure is usually in the range from 1 to 3 bar, and download shared space fixed catalyst layer loaded gas mixture is preferably from 1500 to 4000 or 6000 Nl/l·h or more. Naked is narrow acrolein (load acrolein fixed catalyst layer) is usually from 90 to 190 Nl/l·l, or to 290 Nl/l·h or more. Load acrolein is particularly preferably above 110, or 120, or 130, or 135 Nl/l·h, or ≥140 Nl/l·h, or ≥150 Nl/l·h, ≥160 Nl/l·h, as the high point of overheating causes increased proposed according to the invention the exhaust With2-HC.

Turning acrolein, based on a single passage of the loaded gas mixture through the fixed catalyst bed is usually advisable ≥90% of the mass. and yet reaching the selectivity of the formation of acrylic acid ≥90% of the mass.

Preferably the reactor with a porous layer having a single zone and multi-pipe, loaded with a gas mixture also flows down from the top. As a means for heat transfer to the second stage appropriate way to use salt melt, preferably consisting of 60% of the mass. potassium nitrate (KPO3and 40% of the mass. sodium nitrite (NaNO2) or 53% of the mass. potassium nitrate (kno3), 40% of the mass. sodium nitrite (NaNO2and 7% of the mass. sodium nitrate (NaNO3). You can, watching through the reactor, as already mentioned, to hold the salt melts and loaded gas mixture as in the co-current and counter-current. The salt melt is preferably carried out in a meandering shape around the contact tubes.

If you contact the pipes run from the top down, it is advisable to download contact t the UBA from the bottom up, as follows:

first length from 50 to 80 or 70% of the length of the contact tube or only a catalyst, or a mixture of catalyst and inert material, the latter, based on the mixture, is mass fraction of up to 20% of the mass. (segment);

is it then at length from 20 to 40% of the mass. the total length of the pipe or only a catalyst, or a mixture of catalyst and inert material, the latter, based on the mixture, is mass fraction of up to 50 or up to 40% of the mass. (cut In); and

- then at length from 5 to 20% of the total length of the pipe the filling of inert material (segment a), which preferably is chosen so that it is possible negligible pressure loss.

Preferably a segment is undiluted. In General, when heterogeneous catalyzed partial oxidation in the gas phase from acrolein to acrylic acid (in particular, at high loads acrolein catalyst layer and a high water vapor content downloaded the gas mixture), a line segment may also consist of two successive dilutions of a catalyst (for the purpose of minimizing the temperature of the hot-spots and sensitive point temperature overheating). From the bottom up first up to 20% of the mass. inert material and then > 20% of the mass. up to 50 or 40% of the mass. inert material. In this case, the segment With the two which is preferably undiluted.

To wrap pin tubes from the bottom up loading of the contact tube is turned accordingly.

The above boot options are, in particular, is appropriate in the case, if the catalysts used according to such example of getting 5 of German patent application DE-A 10046928 or according to the German patent application DE-A 19815281 and as inert material steatite rings of geometry 7 mm × 7 mm × 4 mm or 7 mm × 7 mm × 3 mm (external diameter × height × internal diameter). Regarding temperature salt baths really said in the German patent application DE-A 4431949. It usually is chosen so that the achieved conversion of acrolein with a simple single pass is usually ≥90 wt. -%, or ≥95% of the mass. or ≥99% of the mass.

Carrying out partial oxidation from acrolein to acrylic acid can occur with the described catalysts, for example, in a reactor with a fixed bed with two zones and multi-pipe, as described in the German patent application DE-A 19910508. For turning acrolein really said above. Also in the case of the above-described partial oxidation of acrolein in the second reaction stage two-stage oxidation of propylene to obtain acrylic acid in a reactor with a fixed bed with two zones and multi-pipe, for a downloadable gas mixture for the partial oxidation of acrolein it is advisable to apply directly the obtained gas mixture of the partial oxidation directed to the first stage (if necessary, after following its indirect or direct intermediate cooling (for example, by adding secondary air) (as already described above). The oxygen required for the partial oxidation of acrolein, preferably added in the form of air (if necessary, but also in the form of pure molecular oxygen or a mixture of molecular oxygen and inert gas) and, for example, directly add to the mixture obtained gas of the first stage dostato4nogo partial oxidation (propylene-acrolein). However, it can also, as already described, already contained in the gas mixture for the first reaction stage.

When the two-stage partial oxidation of propylene to acrylic acid with the immediate subsequent use of the obtained gas mixture of the first stage partial oxidation to load the second stage partial oxidation consistently connect, as a rule, two reactor with a porous layer having a single zone and multi-pipe (with high load reagents catalyst layer, as, in General, favorably, the method steps of the parallel between reaction the m gas and salt bath (coolant) is preferably see through the shell-and-tube reactor or two reactors with a fixed layer, having two zones and multi-pipe. It is also possible partial mesh serial connection (one zone or two zones or Vice versa).

Between the reactors may be an intermediate cooler, which, if necessary, may contain inert backfill that can perform the filtering function. The temperature of the salt bath reactors with multi-pipes for the first stage of two-stage partial oxidation of propylene to acrylic acid is generally from 300 to 400°C. the temperature of the salt bath reactors with multi-pipe for the second stage partial oxidation of propylene to acrylic acid, partial oxidation from acrolein to acrylic acid is in most cases from 200 to 350°C. in Addition, a means for heat exchange (preferably salt melts) are usually through relevant reactors with a fixed multi-layer pipes in such quantities that the difference between incoming and outgoing temperature, typically is ≤5°C. As already mentioned, the two-stage partial oxidation of propylene to acrylic acid occur in the reactor loading, however, also as described in the German patent application DE-A 10121592.

Also again mention that part of the gas mixture 2 for the first stage ("propylene→acrolein) can be oxidizing cirkuliruyusiy gas (residual gas), coming from partial oxidation.

In this case we are talking about gas containing molecular oxygen, which remains after the separation of the target product (Department of acrolein and/or acrylic acid from the mixture obtained gas partial oxidation and may be partially returned as an inert gas for dilution in the download for the first and/or, if necessary, the second stage partial oxidation of propylene to acrolein and/or acrylic acid.

Preferably such propane, molecular oxygen and, if necessary, oxidizing the circulating gas containing neprevyshenie propane return, but preferably only in heterogeneous catalyzed dehydrogenation of propane acting, if necessary, as a source of propylene.

In General formed within the reactor catalyst loading along individual contact tubes at the end of the first stage of the reaction accordingly modifies the simplest form of the two-stage oxidation for both stages of the partial oxidation of propylene to acrylic acid (such two-stage partial oxidation of propylene in the so-called "single reactor describe, for example, in European patent applications EP-A 1106598, EP-A 911313, EP-A 979813, EP-A 990636 and German patent application DE-A 2830765). Moreover, if necessary,the loading of the contact tubes catalyst interrupted by filling inert material.

However, preferably both phase oxidation is carried out in the form of two serially connected sections of pipe. They can be present in the reactor, forming a transition from one section of pipe to another pipe sections are placed in contact with the pipe (suitable available) filling of inert material. While the contact tube, as a rule, washed with brine, he reaches one, as described above, placed backfill with inert material. Therefore, preferably, both of the contact pipe sections are placed in a spatially separated from each other reactors. And, as a rule, between the two shell-and-tube reactors is an intermediate cooler to reduce, if necessary, the following secondary oxidation acrolein in a mixture of produced gas, which leaves the first zone of oxidation. The reaction temperature in the first reaction stage (propylene → acrolein) is in General, as a rule, at from 300 to 450°C., preferably at from 320 to 390°C. the Reaction temperature in the second reaction stage (acrolein→acrylic acid) is a common, usually at a temperature of from 200 to 370°C., often from 220 to 330°C. the Reaction pressure in both zones of oxidation is expediently from 0.5 to 5, preferably from 1 to 3 bar. Load (Nl/l·h) oxidizing catalysts of reactions is authorized gas at both stages of the reaction is frequently from 1500 to 2500 Nl/l·h, or up to 4000 Nl/l·h Load propylene may be from 100 to 200 or 300 and more Nl/l·h

In principle, both oxidation steps in the proposed according to the invention the method can be carried out in such a way as describe, for example, in German patent applications DE-A 19837517, DE-A 19910506, DE-A 19910508, and also DE-A 19837519.

At both stages of the reaction the excess of molecular oxygen relative to the reaction is stoichiometrically necessary quantity, as a rule, preferably affects the kinetics of the corresponding partial oxidation in the gas phase.

In principle, proposed according to the invention heterogeneous catalyzed partial oxidation in the gas phase propylene to acrylic acid is carried out in only one zone shell-and-tube reactor as described below. Both stages of the reaction occurring in the reactor for oxidation, loaded with one or more catalysts whose active material is an oxide multimetall containing the elements Mo, Fe and Bi, which can catalyze the transformation of both reaction stages. Of course, such a catalyst loading along the reaction coordinate can be continuously or periodically change. Of course, in the embodiment proposed according to the invention the two-stage partial oxidation of propylene to acrylic acid is in the form of two successive stages of oxidation can be partially or completely separated from a mixture of gas produced, left the first stage of oxidation in the same contained, emerged in the first stage of oxidation as a by-product carbon monoxide and water vapor, if necessary, before carrying out the second stage of oxidation. Preferably according to the invention chosen by way of action, which does not provide for such a separation.

As sources for intermediate injection of oxygen, carried out between the two stages of oxidation, is used as already said, along with air (preferably) as a pure molecular oxygen and inert gas, such as CO2, CO, noble gases, N2and/or molecular oxygen diluted with saturated hydrocarbons.

By means of dispensing, for example, cold air to the mixture gas produced in the first reaction stage (propylene→acrolein) in the framework proposed in accordance with the invention, a method is also on the direct path can contribute to cooling before you apply hereinafter referred to as a downloadable component of the gas mixture for the second stage reaction.

According to the invention the partial oxidation of acrolein to acrylic acid is preferably as described in European patent application EP-A 1159246, and highly preferably, as in the international patent applications WO 04/085365, as well as the WO 04/085370. However, according to the invention preferably as a downloadable gas mixture containing acrolein, apply the loaded gas mixture (this can be, in particular, the mixture of gas produced is proposed according to the invention, the partial oxidation in the first phase of propylene to acrolein), which, if necessary, can be supplemented with secondary air so that the ratio of molecular oxygen to acrolein in downloaded to the gas mixture in each case ranged from 0.5 to 1.5. In particular, all examples of the implementation of the aforementioned documents is conducted in such a way as describe in these documents, however, the application loaded gas mixture according to the document. In particular, loaded with a gas mixture for the partial oxidation of acrolein described in this document as a particularly preferable example. The documents of the European patent application EP-A 1159246, international patent application WO 04/085365 and WO 04/085370 considered as one of the components of this document.

It is proposed according to the invention the partial oxidation of acrolein to acrylic acid can be preferably in a fixed bed of catalyst with increased loading acrolein, which has at least two temperature zones, as icyhot in European patent application EP-A 1159246.

That is, the preferred implementation is proposed according to the invention the partial oxidation of acrolein to acrylic acid is proposed according to the invention in such a way that the loaded gas mixture containing acrolein, carried out through the filling of the catalyst fixed bed whose active material is an oxide multimetall containing the elements Mo and V, provided that

- the filling of the catalyst fixed bed come in two spatially successive temperature zones C, D,

as the temperature of temperature zone, and the temperature of temperature zone D is a temperature in the range from 230 to 320°C,

- filling of the catalyst fixed bed consists of at least two spatially successive zones fillings catalyst fixed bed, and the specific volume of activity within the zone backfill catalyst fixed bed is mostly constant and increases in the direction of flow of the loaded gas mixture containing acrolein, the transition from one zone backfill catalyst fixed bed in another zone backfill catalyst fixed bed (suitable abruptly),

- temperature zone is continued until a conversion of acrolein from 45 to 85 wt. -%,

- when only about the ode loaded gas mixture, containing acrolein, through the filling of the catalyst fixed bed turning acrolein is ≥90% of the mass. and selectivity of the formation of acrylic acid, based on converted acrolein, ≥ 90% of the mass.,

- the temporal sequence in which the loaded gas mixture containing acrolein, flows through temperature zones C, D, corresponds to the alphabetic sequence of temperature zones,

- load filling of the catalyst fixed bed by acrolein contained in the download of the gas mixture is ≥70 Nl acrolein/l backfill catalyst fixed bed · h, and

- the difference between the Tmaxs-TDformed from the maximum temperature Tmaxswhich has loaded the gas mixture within the temperature zone C and the maximum temperature TDthat has downloaded the gas mixture within the temperature zone D is ≥0°C,

and which preferably additionally differs in that the transition from temperature zone in the temperature zone D in the filling of the catalyst with a porous layer does not coincide with the transition from the zone backfill catalyst fixed bed in another zone backfill catalyst fixed bed.

More detailed data for this image are in the international patent application WO 04/085370, which is only a single component of this document, and in the next passage of this document when describing a particularly preferred two-stage partial oxidation of propylene to acrylic acid.

This preferred two-stage partial oxidation of propylene to acrylic acid can be preferably as described in European patent application EP-A 1159248, as well as in the international patent application WO 04/085367, but with the difference that as a starting reaction gas mixture for the first stage oxidation of propylene to acrolein) apply proposed according to the invention the gas mixture 2 (in particular, in the examples of implementation of the European patent application EP-A 1159248, as well as international patent application WO 04/085367, both of which form a single component of this document).

Particularly preferably, however, the partial oxidation is carried out according to the international patent application WO 04/085369, which is a single component of this document, but with the difference that as a starting reaction gas mixture for the first stage oxidation of propylene to acrolein) apply proposed according to the invention the gas mixture 2 (in particular, in the examples of implementation of the international patent application WO 04/085369).

That is, initially proposed gas mixture 2 in the first stage reaction is conducted through the acipco catalyst fixed bed 1, whose active material is an oxide multimetall containing at least one of the elements Mo, Fe and Bi, provided that

- the filling of the catalyst fixed bed 1 come in two spatially successive temperature zones a, b,

as the temperature of temperature zone a and the temperature of temperature zone b is a temperature in the range from 290 to 380°C,

the catalyst loading with a fixed layer 1 consists of at least two spatially successive zones backfill catalyst fixed bed, and the specific volume activity within the zone backfill catalyst fixed bed is basically constant and increases in the direction of flow of the gas mixture 2 in the transition zone backfill catalyst fixed bed in another zone backfill catalyst fixed bed (suitable abruptly),

- temperature zone And continues until the conversion of propene from 40 to 80 wt. -%,

- in a single passage of the gas mixture 2 by filling the catalyst fixed bed 1 conversion of propene is ≥90% of the mass. and selectivity of the formation of acrolein is ≥90% of the mass, calculated on converted propene,

- the temporal sequence in which the gas mixture 2 flows through temperature zones a, b, corresponding to the alphabetical sequence of temperature zones A, In,

- load filling of the catalyst fixed bed 1-propene contained in the gas mixture 2 is ≥90 Nl of propene/l of filling the catalyst fixed bed · h, and

- the difference between the Tmax-Tmaxvformed from the maximum temperature Tmaxthat is, the gas mixture 2 within the temperature zone a, and the maximum temperature Tmaxvthat is, the gas mixture 2 within the temperature zone is ≥ 0°C,

then the temperature of the mixture produced gas leaving the first stage of the reaction, if necessary, reduced by cooling, to the mixture produced gas, if necessary, add molecular oxygen and/or inert gas, preferably optionally, the air, and then as acrolein, molecular oxygen and loaded gas mixture containing at least one inert gas which contains molecular oxygen and the acrolein in a molar ratio of O2:C3H4O≥0.5, and in the second stage reaction is carried out through the filling of the catalyst fixed bed 2 whose active material is an oxide multimetall containing at least one of the elements Mo and V, provided that

- filling of the catalyst fixed bed 2 is in two spatially successive temperature zones C, D,

as the temperature temperature zone, and the temperature of temperature zone D is a temperature in the range from 230 to 320°C,

- filling of the catalyst fixed bed 2 consists of at least two spatially successive zones fillings catalyst fixed bed, and the specific volume of activity within the zone backfill catalyst fixed bed is mostly constant and increases in the direction of flow of the loaded gas mixture containing acrolein, the transition from one zone backfill catalyst fixed bed in another zone backfill catalyst fixed bed (suitable way irregular),

- temperature zone is continued until a conversion of acrolein from 45 to 85 wt. -%,

- when only the passage of the loaded gas mixture containing acrolein, through the filling of the catalyst fixed bed 2 turning acrolein is ≥90% of the mass. and selectivity of the formation of acrylic acid, based on converted acrolein, ≥80 wt. -%,

- the temporal sequence in which the loaded gas mixture containing acrolein, flows through temperature zones C, D, corresponds to the alphabetic sequence of temperature zones C, D,

- load filling of the catalyst fixed bed 2 acrolein contained in the download of the gas mixture is ≥70 IO and is of rolein/l backfill catalyst fixed bed 2·h, and

- the difference between the Tmaxs-TDformed from the maximum temperature Tmaxsthat has downloaded the gas mixture within the temperature zone C and the maximum temperature TDthat has downloaded the gas mixture within the temperature zone D is ≥0°C,

if preferred, provided that the method preferably additionally differs by the fact that the transition from temperature zone a to temperature zone in the filling of the catalyst fixed bed 1 or the transition from temperature zone in the temperature zone D in the filling of the catalyst fixed bed 2 does not coincide with the transition from the zone backfill catalyst fixed bed in another zone backfill catalyst fixed bed.

In this case, the temperature of temperature zone understand the temperature in temperature zone a part of the filling of the catalyst fixed bed for the proposed according to the invention method, however, in the presence of chemical reaction. If this temperature is not constant within the temperature zone, the concept of temperature temperature zones implies (numeric) the average temperature of the filling of the catalyst fixed bed along the reaction zone. It is essential that maintaining a uniform temperature is otdelnyh temperature zones occurs largely independently of each other.

As heterogeneous catalyzed partial oxidation in the gas phase of propene to acrylic acid and heterogeneous catalyzed partial oxidation in the gas phase of acrolein to acrylic acid is expressed by an exothermic reaction, the temperature of the mixture of the reaction gases in a jet passing through the filling of the catalyst fixed bed 1 or the filling of the catalyst fixed bed 2, as a rule, differs from the temperature of temperature zone. Usually it is higher than the temperature of temperature zone and flows within temperature zone, as a rule, the maximum (the maximum point of overheating) or falls on the basis of the maximum value.

When proposed according to the invention method, as a rule, the difference between the Tmax-Tmaxvis not more than 80°C. According to the invention preferably Tmax-Tmaxvis ≥3°C and ≤70°C. At the highest degree, preferably Tmax-Tmaxvas proposed according to the invention the method is ≥20°C and ≤60°C.

According to the invention the necessary difference Tmax-Tmaxvregulated by the implementation of proposed according to the invention method in a case from rather low (≥90 Nl/l·h and ≤160 Nl/l·h) loads of propene backfill catalyst with a porous layer 1 is generally then, when the, on the one hand, as the temperature of the reaction zone a and the temperature of the reaction zone is in the range from 290 to 380°C. and, on the other hand, the difference between the temperature of the reaction zone In (TBand the temperature of the reaction zone And (TA), that is, TB-TA, ≤0°C and ≥-20°C or ≥-10°C ≤0°C and ≥-5°C, or often ≤0°C and ≥-3°C.

In the implementation proposed in accordance with the invention, a method (according to the invention preferably) higher propene loadings (≥160 Nl/l·h and ≤300 Nl/l·h, or ≤600 Nl/l·h) required according to the invention the difference of the Tmax-Tmaxvregulated usually when, on the one hand, as the temperature of the reaction zone a and the temperature of the reaction zone is in the range from 290 to 380°C and TB-TAis ≥0°C and ≤50°C or ≥5°C and ≤45°C or ≥10°C and ≤40°C or ≥15°C and ≤30°C ≤35°C (e.g., 20°C or 25°C).

The above content is about the differences between the temperatures TB-TAindeed systematically when the temperature of the reaction zone And is in the preferred range from 305 to 365°C. or in your preferred area from 310 to 340°C.

As proposed according to the invention the method load propene backfill catalyst fixed bed 1 can thus be, for example, ≥90 Nl/l·h and ≤300 Nl/l·h, or ≥nl/l·h and ≤280 Nl/l·h or ≥130 Nl/l·h and ≤260 Nl/l·h, or ≥150 Nl/l·h and ≤240 Nl/l·h, or ≥170 Nl/l·h and ≤220 Nl/l·h, or ≥190 Nl/l·h and ≤200 Nl/l·h

According to the invention preferably the temperature zone And continues until the conversion of propene from 50 to 70% of the mass. or from 60 to 70% of the mass.

When proposed according to the invention method, as a rule, the difference between the Tmaxs-TDis not more than 75°C. According to the invention preferably Tmaxs-TDis ≥3°C and ≤60°C. At the highest degree, preferably Tmaxs-TDas proposed according to the invention the method is ≥5°C and ≤40°C.

According to the invention the necessary difference Tmaxs-TDregulated by the implementation of proposed according to the invention method in a case from rather low (≥70 Nl/l·h and ≤150 Nl/l·h) loads acrolein backfill catalyst with a porous layer 2 is usually when, on the one hand, as the temperature of the reaction zone and the temperature of the reaction zone D is in the range from 230 to 320°C and, on the other hand, the difference between the temperature of the reaction zone D (TDand the temperature of the reaction zone (TC), that is, TD-TC, ≤0°C and ≥-20°C or ≥-10°C ≤0°C and ≥-5°C, or often ≤0°C and ≥-3°C.

In the implementation proposed in accordance with the invention, a method (according to the invention preferably) high load is Oh with propene (≥150 Nl/l·h and ≤300 Nl/l·h, or ≤600 Nl/l·h) is required, when according to the invention the difference of the Tmaxs-TDregulated usually when, on the one hand, as the temperature of the reaction zone and the temperature of the reaction zone D is in the range from 230 to 320°C and TD-TCis ≥0°C and ≤40°C or ≥5°C or ≤35°C or 30°C and ≤10°C, ≤25°C or ≤20°C or ≤15°C.

The above content is about the differences between the temperatures TD-TCindeed systematically when the temperature of the reaction zone is preferred region from 250 to 300°C or in the preferred region from 260 to 280°C.

As proposed according to the invention the method load acrolein backfill catalyst fixed bed 2 can thus be, for example, ≥70 Nl/l·h or ≥90 Nl/l·h and ≤300 Nl/l·h, or ≥110 Nl/l·h and ≤280 Nl/l·h or ≥130 Nl/l·h and ≤260 Nl/l·h, or ≥150 Nl/l·h and ≤240 Nl/l·h, or ≥170 Nl/l·h and ≤220 Nl/l·h, or ≥190 Nl/l·h and ≤200 Nl/l·h

According to the invention preferably temperature zone lasts until the conversion of propene from 50 to 85 mol%. or from 60 to 85 mol%.

With pressure on both stages of the reaction may be located below the normal pressure (for example up to 0.5 bar)or above normal pressure. Usually working pressure at both stages of the reaction is when the values from 1 to 5 bar, h is a hundred from 1 to 3 bar.

Typically, the working pressure in any of the two reaction stages does not exceed 100 bar.

When you described the way the conversion of propene, based on a simple pass backfill catalyst fixed bed 1, as a rule, is ≥92 mol%. or ≥94 mol%. Selectivity multiplying the values (the amount of education acrolein and formation of by-products of acrylic acid) in a suitable known method selection (see in this document the recommended catalysts) backfill catalyst with a porous layer 1 is systematically ≥92% mol., or ≥94 mol%, often ≥95 mol%, or ≥96 mol%, or ≥97 mol%.

When the above-described method, as a rule, the load acrolein backfill catalyst fixed bed 2, in addition, about 10 Nl/l·h, frequently about 20 or 25 Nl/l·h is below the load propene backfill catalyst fixed bed 1. This is initially due to the fact that at the initial stage of the reaction, conversion of propene and selectivity of the formation of acrolein, as a rule, do not reach any 100%. An additional part may occur from secondary feed of oxygen.

When you described the way the transformation of acrolein, based on a simple pass backfill catalyst fixed bed 2, as a rule, is ≥92 mol%. or ≥94 mol%, or ≥ 98 mol%. and often even ≥99 mol%. or the more.

When a suitable known method the choice of fillings catalyst with a porous layer 1 and 2 (see in this document the recommended catalysts) the selectivity of the formation of acrylic acid, balanced with the above-described method steps through both stages of the reaction, based on converted propene, is at values ≥83% of the mass, often with ≥85% wt., or ≥88 wt. -%, often when ≥90% wt., or ≥93% of the mass.

Also mention that the proposed according to the invention, partial oxidation and/or oxidation of ammonia to the environment can be performed so that the first through the catalyst loading conducting the reaction gas mixture, which contains no oxygen. In this case, required for the partial oxidation of the oxygen provide in the form of the oxygen lattice. The next phase of the recovery gas containing oxygen (e.g. air, oxygen-enriched air or air depleted in oxygen), restores the fixed catalyst bed, in order then to obtain a mixture of the reaction gases free from oxygen, etc.

In General, the catalyst layers within the proposed according to the invention, partial oxidation and/or ammonium oxidation in the environment is chosen so (for example, by dilution with inert material)that the difference of temperatures between the maximum point pen is grave mixture of the reaction gases in a separate reaction zones and the corresponding temperature of the reaction zone does not exceed, typically 80°C. In most cases, this difference of temperature is ≤ 70°C., frequently from 20 to 70°C. in Addition, the catalyst layers for security reasons known to the specialist way is chosen so (for example, by dilution, for example, inert material)that "peak-to-salt-temperature sensitivity (sensitivity temperature) according to the definition in the European patent application EP-A 1106598 is ≤9°C or ≤7°C or ≤5°C or ≤3°C.

Under load the layer of catalyst that catalyzes one step of the reaction, the reaction gas in this document to understand the amount of reaction gas in normality (= IO; the volume in liters, which is the corresponding amount of reaction gas at normal conditions (0°C, 1 bar), which takes place in one hour through one liter of catalyst). Load in the corresponding method may also include only one component of the reaction gas.

The separation of the target product P produced from a mixture of gas (gas mixture 3), obtained by heterogeneous catalyzed partial oxidation in the gas phase and/or partial oxidation of ammonia to the environment can occur at at least one stage of separation in a known manner. And usually, at least one target product P on one main stage of separation is transferred from the gas to the new phase in the liquid phase (pre-gas mixture 3, if necessary, cool). This may occur, for example, by partial or complete, and, if necessary, fractionation condensation of the target product P (e.g., acrolein and/or acrylic acid) and/or through the absorption of at least one target product P from the gas mixture 3 in water or an organic solvent (that is, it is also possible layers to apply fractionation condensation and/or absorption of water or aqueous solutions). According to the invention as the main stage of separation are mostly preferred fractionation condensation and/or absorption in water or aqueous solutions, as happens to them, particularly characteristic of the exhaust With2-HC. In the case of acrylic acid and/or acrolein as the target product is used all suitable absorbers, such as water, aqueous solutions of lower carboxylic acids, and hydrophobic organic solvents such as a mixture of diphenyl and simple diphenyl ether (for example, Diphyl®) or a mixture of Diphyl (from 75 to 99.9 wt. -%) and dimethylphthalate (from 0.1 to 25 wt. -%). In the case of acrylic acid mixture produced gas (gas mixture 3)containing the target product P, preferably by fractional condensation. Main compartment (in particular, in the case of acrylic acid) can occur, for example, as described in the following documents (cf., for example, European patent application EP-A 1388533, EP-A 1388532, German patent application DE-A 10235847, European patent application EP-A 792867, international patent application WO 98/01415, European patent application EP-A 1015411, EP-A 1015410, international patent application WO 99/50219, WO 00/53560, WO 02/09839, German patent application DE-A 10235847, international patent application WO 03/041833, German patent application DE-A 10223058, DE-A 10243625, DE-A 10336386, European patent application EP-A 854129, U.S. patent 4317926, German patent application DE-A 19837520, DE-A 19606877, DE-A 190501325, DE-A 10247240, DE-A 19740253, European patent application EP-A 695736, EP-A 982287, EP-A 1041062, EP-A 117146, German patent application DE-A 4308087, DE-A 4335172, DE-A 4436243, DE-A 19924532, DE-A 10332758 a DE-A 19924533). Department of acrylic acid can be performed as well as in European patent applications EP-A 982287, EP-A 982289, German patent applications DE-A 10336386, DE-A 10115277, DE-A 19606877, DE-A 19740252, DE-A 19627847, European patent applications EP-A 920408, EP-A 1068174, EP-A 1066239, EP-A 1066240, international patent applications WO 00/53560, WO 00/53561, German patent application DE-A 10053086 and European patent application EP And 982288. Preferably the branch, as in figure 7 of the international patent application WO/0196271 or as described in the German patent application DE-A 102004032129 and equivalent patents. Favorable methods of separation are also the methods described in international patent applications WO 2004/063138, WO 2004/035514,DE-A 10243625 and DE-A 10235847. Following processing with the resulting crude acrylic acid can be, for example, as described in the documents of international patent applications WO 01/77056, WO 03/041832, WO 02/05469, WO 03/078378 and WO 03/041833.

Translated at least one target product P in the condensed phase now according to the invention it is important, as a rule, also within the target response educated serial products C2-HC contained as side components in a mixture of reactive gases, such as acetic acid, acetaldehyde and/or acetonitrile, transfer in the condensed phase.

That is, separation of the target product are suggested according to the invention method, the exhaust C2goes out of circulation.

For example, by steaming air or nitrogen and/or by desorption is possible to separate these components C2relatively simply from the condensed phase containing at least one target product P. If necessary, in addition to this the Department may then either exclusively rectificate.

A common feature of the previously mentioned methods section is that, for example, on the surface of the separation column containing, for example, respectively effectively divided in elements, in the lower part of which serves, at least, the mixture produced g is for, containing at least one target product, usually after preliminary direct and/or indirect cooling, usually remains the flow of residual gas, which mainly contains the components of the mixture produced gas (gas mixture 3), whose boiling point at normal pressure (1 bar) is ≤-30°C (i.e. trudnosorbiruemye or volatile components).

In the lower part of the separation columns typically occur volatile ingredients the ingredients of the mixture produced gas, including respectively at least one target product P and volatile side components that are similar to the target product P, in the condensed phase.

Components of the residual gas in the first place, are propane, optionally, propylene, not turned into a partial oxidation and/or oxidation in the ammonia phase, molecular oxygen, and often other inert diluting gases used in partial oxidation, such as, for example, nitrogen and carbon dioxide. The residual gas may contain water vapor, depending on the applied method of separation only in trace quantities or in quantities from 20% of the mass. or more.

From the rest of the main gas according to the invention preferably return (oxidative circulating gas), at least one (before occhialino with the composition of the residual gas) propane, molecular oxygen and, if appropriate, converted propylene, and a partial quantity containing acrolein (preferably the total amount, if necessary, but only half, or two thirds, or three-thirds of this total), the feed stream contained as propane in the first stage reaction (dehydrogenation). A partial amount of residual gas, however, you can also return one or both phase partial oxidation and/or burned for energy recovery.

When processing the condensed phase for separation of the target product), we can obtain the following residual gases, as they usually try to return the number is not converted propane, generally contained in the mixture gas produced at the first stage reaction and get back in the Department of the target product. They contain, as a rule, even though propane and, if appropriate, propylene and under circumstances acrolein, often, however, no molecular oxygen. They are usually together with the main residual gas combined into a common residual gas is returned to the dehydrogenation of propane and/or oxidisation propane serving as a source of propylene. But it is also possible, and a separate application following such residual gases.

Thanks predpochtite the flax total return total residual gases in a continuous mode of operation can thus occur continuous conversion of propane to acrylic acid and/or acrolein or other target products R.

Thus it is essential that described by returning to the dehydrogenation used as a source of propylene, in the last reach of the conversion of propane to propylene with almost complete selectivity.

The advantage of this method is given both at low (≤30% mass.), and high (≥30% of the mass.) transformations dehydrogenation (based on single pass of fresh pre-purified propane through dehydration). In General, it is beneficial if such return oxidative circulating gas if the hydrogen content in the initial mixture of the reaction gases to the classical heterogeneous catalyzed dehydrogenation is in at least the stoichiometric ratio (in relation to the combustion of oxygen to water) for the amount of oxygen that is returned through the oxidation of circulating the gas in this source the reaction gas mixture.

Of course, before returning circulating oxidative gas or other residual gases to the first stage reaction can be partially or substantially completely separated from the same propane and propylene various components (they can be, for example, O2, CO, CO2H2O, N2noble gases, lower aldehydes, alcancarao acid, maleic acid anhydride, benzaldehyde, and so on). With this separation can also be bound exhaust With 2. Application of the proposed according to the invention pre-separation can be made, however, simpler and/or less.

For example, this separation With3-HC, as already described, can occur by absorption with subsequent desorption and/or Stripping (and also repeated use of sinks) in the high-boiling hydrophobic organic solvent. The following features of the Department are adsorption, distillation, membrane method and partial condensation. Preferably such methods of separation is carried out at increased pressure.

When the use of dehydrogenation catalysts, which are relatively sensitive to oxygen or compounds containing oxygen, before returning the circulating gas data oxygenates is separated from the circulating gas in the first reaction stage.

This separation of oxygen can also be performed consciously, to the first stage reaction by partial combustion of propane to raise the reaction gas mixture to the desired temperature dehydrogenation.

The above way of circulating gas is used appropriately, if partial oxidation is the partial oxidation of ammonia to the environment of propylene to Acrylonitrile or partial oxidation of propylene to propylene oxide. Then it is also according to the respectively applicable, if the dehydrogenation of propane replace the isobutane and isobutene in the appropriate way to partially oxidize partial oxidation to methacrolein and/or methacrylic acid.

At this place again recorded that the main compartment of acrylic acid from the obtained according to the invention of acrylic acid as the target product contained a mixture of produced gas (gas mixture 3) preferably occurs in such a way that, if necessary, by direct and/or indirect cooling of the cooled mixture gas produced in the column containing effectively divided in elements, in side output of crude acrylic acid (e.g., to itself) condense in an ascending fractionation and/or absorb water or aqueous solution, as described, for example, in international application WO 2004/035514 and German application patent DE-A 10243625. Taken raw acrylic acid is then preferably cast suspension crystallization and educated in this suspension crystallized acrylic acid is separated preferably by washing the column from the remaining mother liquor. This is preferable as the washing liquid used melts pre-separated in the wash column Chris who allow acrylic acid. In addition, wash columns are preferably columns with forced transport of the crystal layer. Particularly preferably it is about hydraulic (e.g., TNO wash column) or a mechanical wash column. In particular, it is possible to follow the description of the international patent applications WO 01/77056, WO 03/041832 and WO 03/041833. That is, preferably the remaining mother liquor in return fractionation condensation (see also European patent application EP-A 1015410). The exhaust side components is usually lower side output raw acrylic acid than pure stream.

When applying exclusively stage of crystallization of the thus obtained acrylic acid with a purity of ≥99.8% of the mass, and which is exclusively suitable for superabsorbers based on poly-Pas-acrylate. Also recorded that the benefit is proposed according to the invention of the method steps, in principle, is that in all places in this document, including examples of implementation, describe where and/or occur backfill catalyst diluted with an inert material, it is possible to use (apply) the corresponding catalysts for a similar length of the layers is also not diluted.

However, for proposed according to the invention, a method is also valid profile the requirements established in the German patent applications DE-A 10245585, as well as in DE-A 10246119.

Example

A) preliminary distillation separation of raw propane

Distillation column has an internal diameter of 50 mm and contains 40 equally spaced located bubble cap trays (with respectively caps). The distance between two directly consecutive plates is 50 mm. Distillation column, including the cap plate, made of stainless steel. Outside distillation column insulated shell of Armaflex® (25 mm thickness). Heating the bottom of the clones is using evaporators with natural circulation (evaporator Robert), to which the coolant, add hot water at a temperature of 85°C.

Feeding raw propane distillation column occurs at the seventeenth cap plate from below.

Raw propane has the following contents:

95% of the mass. propane,

0,10% of the mass. of propene,

of 1.00% of the mass. n-butene,

for 3.28% of the mass. ISO-butane,

0,60% of the mass. ethane,

86 mass. ppm ethylene and

96 masses. ppm 1-butene.

In the calculation contained propane content2-HC is 0,640% of the mass.

The number of theoretical stages of separation above the place of supply is 10. The number of theoretical stages of separation following months the and submission is 8.

Raw propane supplied to a distillation column in the amount of 300 kg/H. It has a pressure of 18 bar and a temperature of 16°C. Through the throttle device in a distillation column relieve tension. The temperature of the bottom of the column is 72°C at the pressure of the bottom of the columns (the upper boundary of the liquid phase) to 14.10 bar. The temperature of the top of the column is located at 41°C. on Top of the latest cap plates (looking from below) the cooling coil is inserted into the distillation column. It serves a cooling water temperature of 20°Scares the bottom of the pipe for exhaust gases in the upper part of the distillation column output 0,82 kg/h pre-purified propane with a temperature of 40°C in a liquid state.

Pre-purified propane has the following contents:

99,20% of the mass. propane,

0,10% of the mass. of propene,

9 mass. castle n-butene,

600 masses. castle ISO-butane,

0.63 masses. ethane,

91 mass. Casta million of ethylene and

1 mass. castle 1-butene.

In the calculation contained in the propane content of C2-hydrocarbons is 0,644% of the mass. 0.53 kg/h of liquid withdrawn pre-purified propane with a temperature of 40°C return in the form of a circulating liquid on the top tray of the distillation column.

From the bottom of the column 15.9 g/h bottom liquid is continuously removed. It has the following contents:

61,00% of the mass. the AOR-butane,

18,81% of the mass. n-butane,

19,98% of the mass. propane,

269 mass. frequent. nmln of propene and

0.18% mass. 1-butene.

From the bottom liquid of the second distillation column can be separated following the cleared propane, as described in the German patent application DE-A 2413461. Waste liquid of the above composition is suitable, but also in an unexpected way in co-feed to the cracking furnace for paraffin hydrocarbons.

C) two-stage partial oxidation of propane to acrylic acid in the presence of a2-HC

I. Download the gas mixture to the first reactor with a porous layer has the following contents:

wt. -%
nitrogen46,69
oxygen11,84
propane32,53
propenefor 6.81
Ethan0,07
n-butane0,08
ISO-butane0,12
n-butene0,05
ISO-butene/td> 0,13
hydrogen0,07
carbon dioxide0,61
water1,00
ethylene0,00
carbon monoxide0,00

When 2128 Nl/l·h and when the inlet pressure of 2.1 bar so download the first reactor with a fixed bed.

1. The first reactor with a fixed bed stage partial oxidation of propene (propylene) to acrolein

Primerjava means for heat transfer:salt melt consisting of
53% of the mass. potassium nitrate
40% of the mass. sodium nitrite and
7% of the mass. sodium nitrate.
The dimensions of the contact tube:4200 mm total length,
26 mm inner diameter,
30 mm outer diameter,
2 mm wall thickness.

The reactor consists of a cylinder with dual sadami stainless steel (cylindrical feed tube surrounded by a cylindrical external tank). The thickness of the walls everywhere is from 2 to 5 mm.

Inside the deposits of the outer diameter of the cylinder is 168 mm The internal diameter of the feed pipe is about 60 mm

The top and bottom of the cylinder with double walls is closed by a lid or plate.

The contact tube is inserted through a cylindrical feed tube in a cylindrical container, is placed so that the upper or lower end it is derived (uplatnena) through the lid or plate, respectively, about 250 mm

Means for heat transfer locked in a cylindrical tank. To the total length of the contact tube (3700 mm), placed in a cylindrical tank, to ensure as uniform as possible, thermal boundary conditions on the outer wall of the contact tube, a means for heat exchange flows through the bubbling of nitrogen in a cylindrical container.

With rising nitrogen means for heat transfer in a cylindrical feed tube is moved upward, then in the intermediate space between the cylindrical feed tube and a cylindrical external tank again flow down (circulation of such material can also be achieved by pumping (e.g., propeller pump)). Thanks deposited on the outer shell of the electric heat can control the temperature of the means for heat exchange to the desired level. However, there is a cooling of the air.

Download reactor: watching through the reactor, in against the current injected salt melts and the reaction mixture. The reaction gas mixture enters the reactor from the top. In the reaction tube of its type, respectively, at a temperature of 250°C.

The salt melt is injected from below at the inlet temperature of 320°C in the cylindrical feed tube and the top when the temperature at the outlet of the cylindrical feed pipe. The difference between the inlet temperature and the outlet temperature is about 2°C. Average temperature = (temperature at the inlet + outlet temperature)/2.

Download contact tubes: (top to bottom) segment a: 50 cm length

Pre-filling of the rings soapstone (steatite C 220 firms Seham Tec) geometry 7 mm × 7 mm × 4 mm (external diameter × length × internal diameter).

Length: 100 cm length Loading contact pipe homogeneous mixture of 30% of the mass. rings soapstone (steatite C 220 firms Seham TES) geometry 5 mm × 3 mm × 2 mm (external diameter × length × internal diameter) and 70% of the mass. solid catalyst of the segment C.

Section: 170 cm length

Catalyst loading circle solid catalyst (5 mm × 3 mm × 2 mm = external diameter × length × internal diameter) according to example 1 of German patent application DE-A 10046957.

Section D: 50 cm length

Additional filling of the rings soapstone (steatite C 220 firms Seham TES) geometry 7 mm × 7 mm × 4 mm (external diameter × length × internal diameter).

2. Intermediate cooling Prohm and the weft supply of oxygen

The mixture produced gas leaving the first reactor with a fixed bed, with the aim of the intermediate cooling (indirectly via air) down through the connecting pipe (length = 400 mm, inner diameter = 26 mm, wall thickness = 2 mm, material = stainless steel), which is placed centered on the length of 200 mm, load inert filling of beads of steatite (soapstone company Sagem TEC) with a diameter of 5 to 6 mm and directly preventiviauto to the contact tube of the first reactor with a fixed bed.

The gas mixture is injected with a temperature of more than 310°C in the connecting pipe and remove with a temperature of about 140°C. Then to the gas mixture as the source of oxygen mixed with 290 Nl/h of complex air.

The obtained mixed in the static mixer, loaded gas mixture added to the reactor with a fixed bed at a temperature of 220°C. DL-stage partial oxidation of acrolein to acrylic acid.

3. The second reactor with a fixed bed stage partial oxidation of acrolein to acrylic acid.

If you employ one reactor with a fixed bed, which is structurally identical to the reactor for the first stage. Salt melt and reaction gas mixture is introduced into the counter, watching through the reactor. The salt melt is injected from the bottom, the mixture of reaction gases is also

Download the contact tube (bottom to top):

Segment a: 20 cm length

Pre-filling of the rings soapstone (steatite C 220 firms Ceram Tec) geometry 7 mm × 7 mm × 4 mm (external diameter × length × internal diameter).

Length: 100 cm length

Catalyst loading homogeneous mixture of 30% of the mass. rings soapstone (steatite C 220 firms Ceram TEC) geometry 7 mm × 3 mm × 4 mm (external diameter × length × internal diameter) and 70% of the mass. shell catalyst of the segment C.

Cut To: 200 cm length

Catalyst loading annular shell catalyst (7 mm × 3 mm × 4 mm = external diameter × length × internal diameter) according to the example of getting 5 of German patent application DE-A 10046928 (here you can also use similar or corresponding means of the obtained shell catalysts whose active mass, however, has a stoichiometry Mo12V2,8W1,2Cu2,4Oxor Mo12V3,5W1,3Cu2,4Ox).

Segment D: 50 cm length

Additional filling of the rings soapstone (steatite C 220 firms Ceram Tec) geometry 7 mm × 7 mm × 4 mm (external diameter × length × internal diameter).

The second reactor load of about 3850 g/h loaded gas mixture. The average temperature is defined as for the first reactor with a fixed bed, and she is about 274°C.

The conversion of propene in the first the second reactor or 97.7% of the mass. and the transformation of acrolein in the second reactor was 99.4% of the mass.

The content of the mixture produced gas leaving the second reactor with a fixed bed at a temperature of 283°C and a pressure of 1.8 bar:

wt. -%
Nitrogen52,87
Oxygen3,03
Propane27,48
Propene0,14
Methane0
Ethan0,07
N-butane0,08
ISO-butane0,34
N-butene0
ISO-butene0
1,3-butadiene0
Hydrogen0,03
Carbon monoxide0,42
Carbon dioxide1,85
Water a 7.92
Acrolein0,03
Acrylic acid5,3
Acetic acid0,18
Formic acid0,01
Formaldehyde0,17
Benzaldehyde0
The anhydride of maleic acid0,04
Eten0,02

II. Example I is repeated with the following differences:

Download gas mixture in the first reaction stage contains only 44.6% of the mass. nitrogen, but 2.1% of the mass. ethane.

The mixture produced gas leaving the second reactor with a fixed bed, now contains 0,29% of the mass. acetic acid.

III. Example I is repeated with the following differences:

Download gas mixture in the first reaction stage contains only 44.7 per cent of the mass. nitrogen, but only 2.0% of mass. of ethylene.

The mixture produced gas leaving the second reactor with a fixed bed, now contains 0,38% of the mass. acetic acid.

Application for U.S. patent No. 60/679971 filed 12.05.2005 included in the proposed invention as the reference literature.

Concerned with the into account the above-mentioned description, there are numerous changes and deviations from the proposed invention. Therefore, it can be expected that the invention can be implemented in the framework of the attached claims, other than here particularly describe.

1. The method of obtaining at least one of the products of acrolein and acrylic acid by the partial oxidation of propylene, in which
a) pre-purified propane turn on the first stage of the reaction in the presence of and/or with the exclusion of molecular oxygen, at least one dehydrogenation of the group, including homogeneous dehydrogenation, heterogeneous catalytic dehydrogenation, homogeneous oxidisation and heterogeneous catalytic oxidisation, and get gas mixture 1 containing not converted propane and educated propylene, and
b) if necessary, of the total amount or a partial amount of the gas mixture 1 is separated partial quantity contained therein other than propane and propylene components, such as hydrogen, carbon monoxide, water vapor, and/or, if necessary, convert it into other compounds, such as water and carbon dioxide, and get the gas mixture 1'containing propane and propylene, and at least one following stage reaction
c) the gas mixture 1, or gas is th mixture, 1' or the mixture formed from the gas mixture 1' and the remaining gas mixture 1 as a component of the gas mixture 2 is subjected to heterogeneous catalytic gas-phase partial oxidation of propylene contained in the gas mixture 1 and/or gas mixture 1', and get gas mixture 3 containing at least one product,
d) at least one stage of separation from the gas mixture 3 separate product and with the remaining residual gas, at least, propane back to the first stage reaction, wherein the pre-purified propane from a crude propane, which contains
≥90 wt.% propane,
≤99 wt.% propane and propylene,
≥100 parts by weight per million hydrocarbon having 2 carbon atoms, and
≥100 parts by weight per million of hydrocarbons having 4 carbon atom,
get under the condition that the crude propane is sent to distillation column and above the place of filing take pre-purified propane provided that the content of hydrocarbons having 2 carbon atoms, in wt.% in the calculation contained propane into the cleared propane is more than 100% relevant content in the crude propane and hydrocarbons having 4 carbon atoms, in wt.% in the calculation contained propane into the cleared propane is at most 50% of the corresponding with what the actual content in the crude propane.

2. The method according to claim 1, wherein the crude propane contains ≥200 parts by weight per million hydrocarbon having 2 carbon atoms.

3. The method according to claim 1, wherein the crude propane contains ≥800 parts by weight per million hydrocarbon having 2 carbon atoms.

4. The method according to claim 1, characterized in that the hydrocarbon having 2 carbon atoms contained in the crude propane, up to at least 90 wt.% consist of ethane and ethylene.

5. The method according to claim 1, characterized in that the hydrocarbon having 2 carbon atoms contained in the crude propane, up to at least 50 wt.% consist of ethane.

6. The method according to claim 1, characterized in that the hydrocarbon having 2 carbon atoms contained in the crude propane, up to at least 70 wt.% consist of ethane.

7. The method according to claim 1, wherein the crude propane contains ≥200 parts by weight per million of hydrocarbons having 4 carbon atoms.

8. The method according to claim 1, wherein the crude propane contains ≥500 parts by weight per million of hydrocarbons having 4 carbon atoms.

9. The method according to claim 1, characterized in that the hydrocarbons having 4 carbon atoms contained in the crude propane, up to at least 80 wt.% consist of Bhutan.

10. The method according to claim 9, characterized in that the butane contained in the crude propane, up to ≥50 wt.% is ISO-butane.

11. The method according to claim 1, characterized in that the calculation contained in the propane content of carbohydrate is birth, having 4 carbon atoms, in wt.% in the pre-purified propane is a maximum of 30% of the relevant content in the crude propane.

12. The method according to claim 1, characterized in that the calculation contained in the propane content of hydrocarbons having 4 carbon atoms, in wt.% in the pre-purified propane is a maximum of 1% of the corresponding content in the crude propane.

13. The method according to claim 1, characterized in that the calculation contained in the propane content of hydrocarbons having 2 carbon atoms, in wt.% in the pre-purified propane is not less than 85% of the corresponding content in the crude propane.

14. The method according to claim 1, characterized in that the calculation contained in the propane content of hydrocarbons having 2 carbon atoms, in wt.% in the pre-purified propane is not less than 90% of the relevant content in the crude propane.

15. The method according to claim 10, characterized in that the content of pre-purified propane to ISO-butane is ≤1000 parts by weight per million

16. The method according to claim 10, characterized in that the content of pre-purified propane to ISO-butane is ≤100 parts by weight per million

17. The method according to claim 1, characterized in that the distillation column as efficiently separated embedded elements includes a plate for mass transfer.

18. The method according to claim 1, characterized t is m, what distillation column as efficiently separated embedded elements includes valve plates.

19. The method according to claim 1, wherein the distillation column has from 5 to 25 theoretical stages of separation.

20. The method according to claim 1, characterized in that the pressure of the upper part of the distillation column is ≥5 bar and ≤25 bar.

21. The method according to claim 1, characterized in that the temperature of the bottom of the distillation column is ≤100°C.

22. The method according to claim 1, characterized in that the supply of crude propane distillation column occurs in such a way that the number of theoretical stages of separation above the place of supply is greater than the number of theoretical stages of separation below the feed.

23. The method according to claim 1, wherein the pre-purified propane is extracted in the upper part of the distillation column.

24. The method according to claim 1, wherein the pre-purified propane is extracted from the distillation column in a gaseous form.

25. The method according to claim 1, wherein the distillation column has a condenser top, water cooled.

26. The method according A.25, wherein water is fed to the capacitor upper part at temperatures ≥0°C and ≤40°C.

27. The method according to claim 1, wherein the pre-purified propane is extracted from rect Picatinny columns in liquid form.

28. The method according to claim 1, wherein the pre-purified propane to at least 99 wt.% consists of propane, propylene, ethane and ethylene.

29. The method according to claim 1, wherein all of the reaction stage is carried out in the reaction zone and the catalyst loading there.

30. The method according to claim 1, characterized in that the first reaction stage is heterogeneous catalytic oxidisation.

31. The method according to claim 1, characterized in that the first reaction stage is heterogeneous catalytic dehydrogenation.

32. The method according to p, characterized in that the heterogeneous catalytic dehydrogenation spend the adiabatic method.

33. The method according to p, characterized in that the heterogeneous catalytic dehydrogenation is conducted autothermal method.

34. The method according to p, characterized in that the heterogeneous catalytic dehydrogenation is carried out in a lattice reactor.

35. The method according to claim 1, characterized in that the gas mixture contains from 2 ≥0 to 30% vol. water vapour.

36. The method according to claim 1, characterized in that at least one reaction stage heterogeneous catalytic gas-phase partial oxidation of propylene is immediate supply of pre-purified propane.

37. The method according to p, wherein at least 25 wt.% General is rebnosci in pre-cleaned propane directly add to, at least one reaction stage heterogeneous catalytic gas-phase partial oxidation of propylene.

38. The method according to claim 1, characterized in that the gas mixture 2 is subjected to two-phase heterogeneous catalytic partial oxidation contained propylene to obtain acrylic acid.

39. The method according to § 38, characterized in that the load propylene catalyst in the first reaction stage is ≥120 Nl/l·h

40. The method according to § 38 or 39, characterized in that the load acrolein fixed catalyst in the second reaction stage is ≥110 Nl/l·h

41. The method according to claim 1, characterized in that at least one stage of separation includes the main stage of separation, in which at least one product is transferred from the gas mixture 3 in the liquid phase.

42. The method according to paragraph 41, wherein the stage main compartment includes a fractional condensation of the gas mixture 3 and/or absorption of the product gas mixture 3 in water or in aqueous solution.

43. The method according to § 42, characterized in that the product is acrylic acid and the main stage separation is carried out in a column containing effectively divided in elements, when the lateral withdrawal of the crude acrylic acid and the crude acrylic acid is subjected to suspension crystallization.

44. The way is about p.43, characterized in that the suspension crystallized acrylic acid, obtained by suspension crystallization, separated with washing the column from the remaining mother liquor.

45. The method according to item 44, wherein the wash column is a wash column with forced transport of the crystal layer.

46. The method according to item 45, wherein the wash column is a hydraulic wash column.

47. The method according to item 46, wherein as the washing liquid used melts crystals of acrylic acid, previously separated in the wash column.

48. The method according to claim 1, characterized in that the distillation column is continuously extract the cubic liquid, which is subjected to an additional distillation process.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method for long-term heterogeneous catalytic partial gas-phase oxidation of an organic starting compound selected from propylene, isobutene, acrolein, methacrolein, propane or isobutane, to the desired organic compound, where the starting gaseous reaction mixture, containing the organic starting compound and molecular oxygen, is first passed through a freshly loaded sold catalyst layer which is filled with separation into two temperature zones A and B, lying in space one behind the other, temperature TA of which is such that the difference ΔTBA between temperature TB of zone B and temperature TA of zone A, which is calculated by taking the greater of the two values as the minuend, is greater than 0°C, such that the starting reaction mixture of gases successively flows through temperature zones A, B, first through A and then B, where temperature zone A extends until conversion of the organic starting compound UA = 15-85 mol %, and in temperature zone B conversion of the organic starting compound increases to a value UB ≥ 90 mol %, and as the operating life increases, temperature of zones A, B is changed in order to compensate for deterioration of quality of the solid catalyst layer, where as the duration of operation increases, temperature of that temperature zone which initially had a lower value, is raised, and the difference ΔTBA between temperature values of both zones is lowered, such that when calculating the difference, temperature of that zone which was initially the higher value, remains as the minuend.

EFFECT: compensating for the deterioration of quality of the solid catalyst layer with long operating life.

21 cl, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method for heterogeneous catalytic gas-phase partial oxidation of at least one initial organic compound selected from propylene, isobutene, acrolein, methacrolein, propane or isobutane with molecular oxygen on a fixed catalyst bed freshly put into a reaction space, in which, for partial oxidation, a reaction gaseous mixture containing at least one initial organic compound and molecular oxygen is passed through the fixed catalyst bed, and reaction heat is removed via indirect heat exchange with a liquid heat carrier directed outside the reaction space, and as the quality of the fixed catalyst bed falls with operation time, not all, but part of the fixed catalyst bed is replaced with part of a replacement fixed catalyst bed in order to restore the quality of the fixed catalyst bed, where the specific volume activity of the replacement part of the fixed catalyst bed is lower than that of the replaced part of the fixed catalyst bed in its fresh state.

EFFECT: deterioration of the quality of the fixed catalyst bed with operation time is compensated for by replacing part of the fixed catalyst bed with a replacement part of the fixed catalyst bed, where the rate of deactivation of the catalyst is lowest in the disclosed method.

10 cl, 2 ex

FIELD: chemistry.

SUBSTANCE: method involves: a) heterogeneously catalysed vapour-phase partial oxidation of a starting organic compound selected from propylene, propane, isobutylene, isobutane, acrolein or methacrolein with molecular oxygen in a parallel-functioning system of oxidation reactors containing catalysts, which results in formation of two gas streams respectively containing the desired compound and respectively formed in one of two systems of oxidation reactors, and b) subsequent extraction of the desired product from two streams of the obtained gas to form at least one stream of crude desired product according to which c) before extraction of two from two streams, the obtained gas is mixed with each other into a mixed stream. In case of change in selectivity of formation of the desired product and/or by-products during operation the entire amount or partial amount of catalyst is replaced in parallel with fresh catalyst not in all parallel-functioning systems of oxidation reactors in which end products contained in the mixed stream are formed.

EFFECT: improved method of obtaining acrolein, acrylic acid, methacrolein or methacrylic acid as the desired product.

2 cl, 4 tbl, 2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of conducting a continuous process of producing acrolein, acrylic acid or mixture thereof from propane in a stable operating mode, according to which: A) propane in a first reaction zone A undergoes heterogeneously catalysed dehydrogenation in the presence of molecular oxygen to obtain a gaseous mixture of products A containing propane and propylene, B) the gaseous mixture of products A, if needed, is fed into a first separation zone A in which a portion or more of components different from propane and propylene is separated therefrom and a gaseous mixture of products A' containing propane and propylene remaining after separation is obtained, C) the gaseous mixture of products A or gaseous mixture of products A' is fed into at least one oxidation reactor of the second reaction zone B, in which propylene contained therein undergoes partial selective heterogeneously catalysed gas-phase oxidation with molecular oxygen to obtain a gaseous mixture of products B, which contains acrolein, acrylic acid or mixture thereof as the desired product, unconverted propane, excess molecular oxygen and, if needed, unconverted propylene, D) in the second separation zone B, the desired product contained therein is separated from the gaseous mixture of products B, and at least a portion of the remaining gas containing propane, molecular oxygen and, if needed, unconverted propylene is returned to the reaction zone A as circulation gas 1 containing molecular oxygen, E) fresh propane is fed into at least one continuous flow process zone selected from a group comprising reaction zone A, separation zone A, reaction zone B and separation zone B, where the said fresh propane is fed at a rate characterised by a given stationary value when realising the process in a stable operating mode, and F) content of molecular oxygen in the gaseous mixture of products B is continuously determined and said value is compared with the desired stationary value needed to realise the process in stable operating mode, characterised by that if at a certain moment in time, content of molecular oxygen in the gaseous mixture of products B exceeds the given desired stationary value, fresh propane is fed into the process right away at feed rate higher than its stationary value, and if at a certain moment in time, content of molecular oxygen in the gaseous mixture of products B is lower than the corresponding given desired stationary value, fresh propane is fed into the process right away at feed rate lower than its stationary value.

EFFECT: used of present method reduces heat loss and prevents a drop in degree of dehydrogenation when producing acrolein, acrylic acid or mixture thereof from propane.

13 cl, 2 ex, 1 dwg

FIELD: chemistry.

SUBSTANCE: according to method A) an input stream of the reaction gaseous mixture A is fed into the input of the first reaction zone A, where the input stream is obtained by merging at least four different gaseous initial streams 1, 2, 3 and 4, where the gaseous initial streams 1 and 2 contain propane, gaseous initial stream 4 is molecular hydrogen and gaseous initial stream 3 is fresh propane, the input stream of the reaction gaseous mixture A is passed at least through one catalyst layer of the first reaction zone A on which, if needed, when feeding other gaseous streams, as a result of heterogeneous catalytic partial dehydrogenation of propane, a stream of products of gaseous mixture A forms, which contains propane and propylene, the stream of products of gaseous mixture A comes out of the first reaction zone A through the corresponding outlet, while splitting said stream into two partial streams 1 and 2 of products of the gaseous mixture A with identical composition, and the partial stream 1 of products of the gaseous mixture A is returned to the first reaction zone A as the gaseous initial stream 1, the partial stream 2 of products of the gaseous mixture A, if needed, is directed to the first separation zone A, in which a portion or more of components contained therein, which are different from propane and propylene, are separated, as a result of which a stream of products of gaseous mixture A' which contains propane and propylene, B) partial stream 2 of products of the gaseous mixture A or a stream of products of gaseous mixture A' is used in a second reaction zone B for supplying at least one oxidation reactor, in which propylene contained in the partial stream 2 of products of gaseous mixture A or in the stream of products of gaseous mixture A' undergoes selective heterogeneously catalysed partial gas-phase oxidation with molecular oxygen to obtain a stream of products of a gaseous mixture B, which contains acrolein, acrylic acid or mixture thereof as the desired product, unconverted propane and, if needed, unconverted propylene, as well as molecular oxygen, the stream of products of gaseous mixture B comes out of reaction zone B, the desired product contained in separation zone B is separated in said separation zone B and at least a portion of residual gas formed after separation and containing unconverted propane, molecular oxygen and, if needed, unconverted propylene, is returned to reaction zone A as gaseous initial stream 2. Gaseous initial streams 2, 3 and 4 as well as, if needed, additional gaseous initial streams different from the gaseous initial stream 1, are merged into a gaseous stream of the working mixture, after which, using this gaseous stream of the working mixture as the working stream, a jet pump is activated, said pump having a nozzle, a mixing section, a diffuser and a suction inlet. Movement of the working stream which is throttled through the nozzle, the mixing section and the diffuser to the input of the first reaction zone A, as well as the suction effect of the suction inlet takes place in the direction of outlet of the stream of products of gaseous mixture A from the first reaction zone A. The pressure drop created in the suction nozzle with splitting of the stream of products of the gaseous mixture A into two partial streams 1 and 2 results in suction of the partial stream 1 of products of the gaseous mixture A, its movement through the diffuser with simultaneous mixture with the working stream on the mixing section and inlet of the formed reaction stream of gaseous mixture A at its inlet point into the first reaction zone A, characterised by that a gaseous initial mixed stream is formed first by merging in random sequence gaseous initial streams 2 and 3, as well as, if needed, additional gaseous initial streams different from gaseous initial streams 1 and 4, and only after that the gaseous initial stream 4 is added to the formed gaseous initial mixed stream to obtain a gaseous mixed working stream.

EFFECT: used of present method reduces heat loss and prevents a drop in degree of dehydrogenation when producing acrolein, acrylic acid or mixture thereof from propane.

7 cl, 4 ex, 4 dwg

FIELD: chemistry.

SUBSTANCE: initial mixture 2 of the reaction gas which contains propylene and molecular oxygen, as well as molecular nitrogen and propane as inert gases - diluents, in which molar ratio of molecular oxygen to propylene O2:C3H6≥1, at high temperature is passed through a fixed catalyst bed, the active mass of which is at least one polymetallic oxide containing Mo, Fe and Bi, in which the initial mixture 2 of the reaction gas, per total volume, contains 7-9 vol. % propylene, 9.8-15.5 vol. % molecular oxygen, 10.5-15.5 vol. % propane and 40-60 vol. % molecular nitrogen, provided that the molar ratio V1 of propane contained in the initial mixture 2 of the reaction gas to propylene contained in the initial mixture 2 of the reaction gas is between 1.5 and 2.2, molar ratio V2 of molecular nitrogen contained in the initial mixture 2 of the reaction gas to molecular oxygen contained in the initial mixture 2 of the reaction gas is between 3.5 and 4.5, and molar ratio V3 of molecular oxygen contained in the initial mixture 2 of the reaction gas to propylene contained in the initial mixture 2 of the reaction gas is between 1.4 and 2.14.

EFFECT: improved method of lowering flash point temperature of a fixed catalyst bed during synthesis of acrolein or acrylic acid or mixture thereof through heterogeneously catalysed gas-phase partial oxidation of propene.

27 cl, 1 dwg, 3 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of lowering the flash point temperature of a fixed catalyst bed during synthesis of acrylic acid through heterogeneously catalysed gas-phase partial oxidation of propylene, in which a) at the first reaction step, propane undergoes heterogeneously catalysed dehydrogenation to obtain a product gas mixture 1, b) a partial amount of components in the formed product mixture 1 which are different from propane and propylene are converted to other compounds if needed and if needed a partial amount of components of the product gas mixture 1 formed at the first reaction step which are different from propane and propylene are separated, wherein a product gas mixture 1', which contains propane and propylene, as well as compounds different from oxygen, propane and propylene, is obtained from the product gas mixture 1, and c) as a component of the initial reaction gas mixture 2 at the second reaction step, the product gas mixture 1 or 1' undergoes heterogeneously catalysed partial oxidation in the gas phase of propylene contained in the product gas mixture 1 or 1' to acrolein, where the product gas mixture 2 is obtained, and d) temperature of the product gas mixture leaving the second reaction step, if needed, is lowered through direct and/or indirect cooling and molecular oxygen and/or inert gas is added to the said mixture 2 if needed, and e) further, as an initial reaction gas mixture 3 at the third reaction step, acrolein contained in the initial reaction gas mixture 3 undergoes heterogeneously catalysed gas-phase partial oxidation to acrylic acid, where the product gas mixture 3 is obtained, and f) acrylic acid and at least unreacted propane and propylene contained in the product gas mixture 3 are separated from the product gas mixture 3 in a separation zone A an then returned to at least the first of three reaction steps, where i) the second reaction step is carried out until achieving propylene degree of conversion Up ≤99 mol % for one-time passage through the zone, and ii) the third reaction step is carried out until achieving acrolein degree of conversion UA ≥96 mol % for one-time passage through the zone. The method involves at least one separate selection for components different from propane and propylene, which contains propane and propylene in amount ≤5 vol %.

EFFECT: low temperature.

39 cl, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing acrylic acid from propylene, involving a first step where propylene is oxidised to acrolein and a second step where acrolein is oxidised to acrylic acid, as well as a step for dehydrating glycerin to acrolein in the presence of a propylene-containing gas. The said step for dehydrating glycerin is carried out before catalytic oxidation of propylene to acrolein in the presence of the supplied propylene-containing gas, or after catalytic oxidation of propylene to acrolein in the presence of a gaseous mixture coming out after oxidation of propylene to acrolein.

EFFECT: method enables partial use of renewable material, while increasing output of acrylic acid.

8 cl, 5 dwg, 6 ex

FIELD: chemistry.

SUBSTANCE: in accordance with the method A) at least two propane-containing gas supply streams are fed into the first reaction zone A, where at least one of the said streams contains fresh propane, and propane fed into this reaction zone undergoes heterogeneous catalytic dehydrogenation with a fixed bed catalyst, obtaining a propane- and propylene-containing gaseous mixture of products A, B) which is extracted from reaction zone A, in the first separation zone, A is separated from at least a portion of components contained in it, which are different from propane and propylene, and the remaining gaseous mixture of products A' which contains propane and propylene C) is used in the second reaction zone B for supplying at least one oxidation reactor, and propylene contained in the gaseous mixture of products A' in at least one oxidation reactor undergoes heterogeneous catalytic two-step gas-phase partial oxidation with molecular oxygen to acrylic acid or a mixture of acrolein and acrylic acid as an end product, as well as to an excess molecular oxygen-containing gaseous mixture of products B, D) which is extracted from the reaction zone B, in the second separation zone B, the end product contained in it is extracted through absorption or fractional condensation, and at least a portion of the remaining residual gas which contains unconverted propane, molecular oxygen, and also if necessary, unconverted propylene are recycled into the reaction zone A as at least one of two propane-containing supply streams, where the said recycling into the reaction zone A is done along the path of the heterogeneous catalysed dehydrogation of propane in that reaction zone such that, at the point for feeding the recycled gas into reaction zone A at least 5 mol % of propane has already undergone dehydrogenation, where the said propane is fed into this reaction zone with other supply streams, where molar ratio of the propylene contained in the reaction gaseous mixture to molecular hydrogen contained in the said mixture within the reaction zone A does not exceed 10.

EFFECT: design of an improved method of obtaining acrolein, acrylic acid or their mixture from propane.

41 cl, 3 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of continuous, heterogeneous, catalytic, partial gas-phase oxidation of at least one organic compound selected from a group comprising propene, acrolein, isobutene, methacrolein, isobutene and propane, in an oxidation reactor loaded with a gas mixture which, along with at least one compound to undergo partial oxidation and molecular oxygen as an oxidation agent, includes at least one diluent gas which is essentially inert in conditions of heterogeneous, catalytic, gas-phase partial oxidation, where the source of oxygen and inert gas for the loaded gas mixture is air which is compressed in a compressor beforehand from a low initial pressure value to a high final pressure value, where before entering the compressor, the air undergoes at least one mechanical separation procedure through which particles of solid substance dispersed in the air can be separated.

EFFECT: method prevents negative effect of solid particles on the air compression stage, undesirable increase in pressure loss and reduction of activity or selectivity of the catalyst.

21 cl, 2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method for long-term heterogeneous catalytic partial gas-phase oxidation of an organic starting compound selected from propylene, isobutene, acrolein, methacrolein, propane or isobutane, to the desired organic compound, where the starting gaseous reaction mixture, containing the organic starting compound and molecular oxygen, is first passed through a freshly loaded sold catalyst layer which is filled with separation into two temperature zones A and B, lying in space one behind the other, temperature TA of which is such that the difference ΔTBA between temperature TB of zone B and temperature TA of zone A, which is calculated by taking the greater of the two values as the minuend, is greater than 0°C, such that the starting reaction mixture of gases successively flows through temperature zones A, B, first through A and then B, where temperature zone A extends until conversion of the organic starting compound UA = 15-85 mol %, and in temperature zone B conversion of the organic starting compound increases to a value UB ≥ 90 mol %, and as the operating life increases, temperature of zones A, B is changed in order to compensate for deterioration of quality of the solid catalyst layer, where as the duration of operation increases, temperature of that temperature zone which initially had a lower value, is raised, and the difference ΔTBA between temperature values of both zones is lowered, such that when calculating the difference, temperature of that zone which was initially the higher value, remains as the minuend.

EFFECT: compensating for the deterioration of quality of the solid catalyst layer with long operating life.

21 cl, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method for heterogeneous catalytic gas-phase partial oxidation of at least one initial organic compound selected from propylene, isobutene, acrolein, methacrolein, propane or isobutane with molecular oxygen on a fixed catalyst bed freshly put into a reaction space, in which, for partial oxidation, a reaction gaseous mixture containing at least one initial organic compound and molecular oxygen is passed through the fixed catalyst bed, and reaction heat is removed via indirect heat exchange with a liquid heat carrier directed outside the reaction space, and as the quality of the fixed catalyst bed falls with operation time, not all, but part of the fixed catalyst bed is replaced with part of a replacement fixed catalyst bed in order to restore the quality of the fixed catalyst bed, where the specific volume activity of the replacement part of the fixed catalyst bed is lower than that of the replaced part of the fixed catalyst bed in its fresh state.

EFFECT: deterioration of the quality of the fixed catalyst bed with operation time is compensated for by replacing part of the fixed catalyst bed with a replacement part of the fixed catalyst bed, where the rate of deactivation of the catalyst is lowest in the disclosed method.

10 cl, 2 ex

FIELD: chemistry.

SUBSTANCE: according to the method: A) at least two initial gas streams containing propane, which form the reaction gas A, are fed into a reaction zone A, where one of said gas streams contains fresh propane; the reaction gas A is passed through at least one catalyst layer in reaction zone A in which partial heterogeneously catalysed dehydrogenation of propane results in formation of molecular hydrogen and propylene; molecular oxygen is fed into reaction zone A and oxidises molecular hydrogen in the reaction gas A to water vapour, and a gaseous product A is collected from reaction zone A, said product containing molecular hydrogen, water vapour, propylene and propane; B) the gaseous product A collected from the reaction zone A, while feeding molecular oxygen, is used in reaction zone B to supply at least one oxidation reactor with reaction gas B which contains molecular hydrogen, water vapour, propane, propylene and molecular oxygen, and propylene contained in reaction gas B undergoes two-step heterogeneously catalysed partial gas-phase oxidation in reaction zone B to obtain a gaseous product B containing acrylic acid as the end product, unconverted propane, molecular hydrogen, water vapour and carbon dioxide as by-products, as well as other secondary components with boiling point lower or higher the boiling point of water; C) gaseous product B is output from the reaction zone B and acrylic acid, water and secondary components with boiling point higher than that of water contained therein are separated in a first separation zone I through fractional condensation or absorption, wherein the residual gas I contains unconverted propane, carbon dioxide, molecular hydrogen, secondary components with boiling point lower than that of water, as well as, if necessary, propylene and molecular oxygen not converted in reaction zone B; D) residual gas I undergoes further treatment by washing carbon dioxide contained therein, separation of a partial amount of residual gas I, as well as, if necessary, separation of molecular hydrogen contained in the residual gas I using a separating membrane; E) after further treatment, unconverted propane-containing residual gas I is returned to reaction zone A as at least one of at least two propane-containing initial streams, where in reaction zone A, a certain amount (M) of molecular hydrogen is oxidised to water vapour, which makes up at least 35 mol % but not more than 65 mol % of the total amount of molecular hydrogen produced in reaction zone A and, if necessary, fed into said reaction zone A.

EFFECT: improved method of producing acrylic acid from propane.

22 cl, 1 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a method of conducting a continuous process of producing acrolein, acrylic acid or mixture thereof from propane in a stable operating mode, according to which: A) propane in a first reaction zone A undergoes heterogeneously catalysed dehydrogenation in the presence of molecular oxygen to obtain a gaseous mixture of products A containing propane and propylene, B) the gaseous mixture of products A, if needed, is fed into a first separation zone A in which a portion or more of components different from propane and propylene is separated therefrom and a gaseous mixture of products A' containing propane and propylene remaining after separation is obtained, C) the gaseous mixture of products A or gaseous mixture of products A' is fed into at least one oxidation reactor of the second reaction zone B, in which propylene contained therein undergoes partial selective heterogeneously catalysed gas-phase oxidation with molecular oxygen to obtain a gaseous mixture of products B, which contains acrolein, acrylic acid or mixture thereof as the desired product, unconverted propane, excess molecular oxygen and, if needed, unconverted propylene, D) in the second separation zone B, the desired product contained therein is separated from the gaseous mixture of products B, and at least a portion of the remaining gas containing propane, molecular oxygen and, if needed, unconverted propylene is returned to the reaction zone A as circulation gas 1 containing molecular oxygen, E) fresh propane is fed into at least one continuous flow process zone selected from a group comprising reaction zone A, separation zone A, reaction zone B and separation zone B, where the said fresh propane is fed at a rate characterised by a given stationary value when realising the process in a stable operating mode, and F) content of molecular oxygen in the gaseous mixture of products B is continuously determined and said value is compared with the desired stationary value needed to realise the process in stable operating mode, characterised by that if at a certain moment in time, content of molecular oxygen in the gaseous mixture of products B exceeds the given desired stationary value, fresh propane is fed into the process right away at feed rate higher than its stationary value, and if at a certain moment in time, content of molecular oxygen in the gaseous mixture of products B is lower than the corresponding given desired stationary value, fresh propane is fed into the process right away at feed rate lower than its stationary value.

EFFECT: used of present method reduces heat loss and prevents a drop in degree of dehydrogenation when producing acrolein, acrylic acid or mixture thereof from propane.

13 cl, 2 ex, 1 dwg

FIELD: chemistry.

SUBSTANCE: according to method A) an input stream of the reaction gaseous mixture A is fed into the input of the first reaction zone A, where the input stream is obtained by merging at least four different gaseous initial streams 1, 2, 3 and 4, where the gaseous initial streams 1 and 2 contain propane, gaseous initial stream 4 is molecular hydrogen and gaseous initial stream 3 is fresh propane, the input stream of the reaction gaseous mixture A is passed at least through one catalyst layer of the first reaction zone A on which, if needed, when feeding other gaseous streams, as a result of heterogeneous catalytic partial dehydrogenation of propane, a stream of products of gaseous mixture A forms, which contains propane and propylene, the stream of products of gaseous mixture A comes out of the first reaction zone A through the corresponding outlet, while splitting said stream into two partial streams 1 and 2 of products of the gaseous mixture A with identical composition, and the partial stream 1 of products of the gaseous mixture A is returned to the first reaction zone A as the gaseous initial stream 1, the partial stream 2 of products of the gaseous mixture A, if needed, is directed to the first separation zone A, in which a portion or more of components contained therein, which are different from propane and propylene, are separated, as a result of which a stream of products of gaseous mixture A' which contains propane and propylene, B) partial stream 2 of products of the gaseous mixture A or a stream of products of gaseous mixture A' is used in a second reaction zone B for supplying at least one oxidation reactor, in which propylene contained in the partial stream 2 of products of gaseous mixture A or in the stream of products of gaseous mixture A' undergoes selective heterogeneously catalysed partial gas-phase oxidation with molecular oxygen to obtain a stream of products of a gaseous mixture B, which contains acrolein, acrylic acid or mixture thereof as the desired product, unconverted propane and, if needed, unconverted propylene, as well as molecular oxygen, the stream of products of gaseous mixture B comes out of reaction zone B, the desired product contained in separation zone B is separated in said separation zone B and at least a portion of residual gas formed after separation and containing unconverted propane, molecular oxygen and, if needed, unconverted propylene, is returned to reaction zone A as gaseous initial stream 2. Gaseous initial streams 2, 3 and 4 as well as, if needed, additional gaseous initial streams different from the gaseous initial stream 1, are merged into a gaseous stream of the working mixture, after which, using this gaseous stream of the working mixture as the working stream, a jet pump is activated, said pump having a nozzle, a mixing section, a diffuser and a suction inlet. Movement of the working stream which is throttled through the nozzle, the mixing section and the diffuser to the input of the first reaction zone A, as well as the suction effect of the suction inlet takes place in the direction of outlet of the stream of products of gaseous mixture A from the first reaction zone A. The pressure drop created in the suction nozzle with splitting of the stream of products of the gaseous mixture A into two partial streams 1 and 2 results in suction of the partial stream 1 of products of the gaseous mixture A, its movement through the diffuser with simultaneous mixture with the working stream on the mixing section and inlet of the formed reaction stream of gaseous mixture A at its inlet point into the first reaction zone A, characterised by that a gaseous initial mixed stream is formed first by merging in random sequence gaseous initial streams 2 and 3, as well as, if needed, additional gaseous initial streams different from gaseous initial streams 1 and 4, and only after that the gaseous initial stream 4 is added to the formed gaseous initial mixed stream to obtain a gaseous mixed working stream.

EFFECT: used of present method reduces heat loss and prevents a drop in degree of dehydrogenation when producing acrolein, acrylic acid or mixture thereof from propane.

7 cl, 4 ex, 4 dwg

FIELD: chemistry.

SUBSTANCE: initial mixture 2 of the reaction gas which contains propylene and molecular oxygen, as well as molecular nitrogen and propane as inert gases - diluents, in which molar ratio of molecular oxygen to propylene O2:C3H6≥1, at high temperature is passed through a fixed catalyst bed, the active mass of which is at least one polymetallic oxide containing Mo, Fe and Bi, in which the initial mixture 2 of the reaction gas, per total volume, contains 7-9 vol. % propylene, 9.8-15.5 vol. % molecular oxygen, 10.5-15.5 vol. % propane and 40-60 vol. % molecular nitrogen, provided that the molar ratio V1 of propane contained in the initial mixture 2 of the reaction gas to propylene contained in the initial mixture 2 of the reaction gas is between 1.5 and 2.2, molar ratio V2 of molecular nitrogen contained in the initial mixture 2 of the reaction gas to molecular oxygen contained in the initial mixture 2 of the reaction gas is between 3.5 and 4.5, and molar ratio V3 of molecular oxygen contained in the initial mixture 2 of the reaction gas to propylene contained in the initial mixture 2 of the reaction gas is between 1.4 and 2.14.

EFFECT: improved method of lowering flash point temperature of a fixed catalyst bed during synthesis of acrolein or acrylic acid or mixture thereof through heterogeneously catalysed gas-phase partial oxidation of propene.

27 cl, 1 dwg, 3 tbl, 3 ex

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of lowering the flash point temperature of a fixed catalyst bed during synthesis of acrylic acid through heterogeneously catalysed gas-phase partial oxidation of propylene, in which a) at the first reaction step, propane undergoes heterogeneously catalysed dehydrogenation to obtain a product gas mixture 1, b) a partial amount of components in the formed product mixture 1 which are different from propane and propylene are converted to other compounds if needed and if needed a partial amount of components of the product gas mixture 1 formed at the first reaction step which are different from propane and propylene are separated, wherein a product gas mixture 1', which contains propane and propylene, as well as compounds different from oxygen, propane and propylene, is obtained from the product gas mixture 1, and c) as a component of the initial reaction gas mixture 2 at the second reaction step, the product gas mixture 1 or 1' undergoes heterogeneously catalysed partial oxidation in the gas phase of propylene contained in the product gas mixture 1 or 1' to acrolein, where the product gas mixture 2 is obtained, and d) temperature of the product gas mixture leaving the second reaction step, if needed, is lowered through direct and/or indirect cooling and molecular oxygen and/or inert gas is added to the said mixture 2 if needed, and e) further, as an initial reaction gas mixture 3 at the third reaction step, acrolein contained in the initial reaction gas mixture 3 undergoes heterogeneously catalysed gas-phase partial oxidation to acrylic acid, where the product gas mixture 3 is obtained, and f) acrylic acid and at least unreacted propane and propylene contained in the product gas mixture 3 are separated from the product gas mixture 3 in a separation zone A an then returned to at least the first of three reaction steps, where i) the second reaction step is carried out until achieving propylene degree of conversion Up ≤99 mol % for one-time passage through the zone, and ii) the third reaction step is carried out until achieving acrolein degree of conversion UA ≥96 mol % for one-time passage through the zone. The method involves at least one separate selection for components different from propane and propylene, which contains propane and propylene in amount ≤5 vol %.

EFFECT: low temperature.

39 cl, 1 ex

FIELD: chemistry.

SUBSTANCE: invention discloses a method for safe continuous heterogeneous catalysed gas-phase partial oxidation of at least one organic starting compound in a reactor, whose stream of loaded gas mixture along with at least one partially oxidisable organic starting compound and molecular oxygen as an oxidising agent contains at least one diluting gas which remains essentially inert under heterogeneous catalysed gas-phase partial oxidation conditions,and is obtained by merging at least two different initial streams, where through online measurement of concentration of one or more selected components in the stream of the loaded gas mixture in one or more initial streams which form the stream of the loaded gas mixture and/or stream of gas mixture of the product, loading of an uncontrolled stream of gas mixture in terms of explosion risk or other is prevented, wherein for online measurement of the partial stream, the analysed gas stream is accordingly continuously fed into the measurement cell of an analysing device and during measurement, said stream comes out of the measurement cell into the free atmosphere, where the analysed gas stream and/or free atmosphere are subject to pressure fluctuations, where the effect of pressure fluctuation of the analysed gas stream and/or free atmosphere on the measured pressure in the measurement cell in the analysing device and therefore on the measurement resulta) is corrected through calculation, based on properties capable of correlation with the gas in the measurement cell and/or b) is minimised based on that the measured in the measurement cell of the analysing device is kept constant or controlled to a constant value using a pressure regulator, independent of the pressure of the analysed gas stream and/or free atmosphere.

EFFECT: high reliability and safety of the process.

18 cl, 4 ex, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to improved combined methods of producing acetic acid and vinyl acetate involving the following steps: (a) obtaining a first stream of product from the first reaction zone containing acetic acid, where the acetic acid is obtained via an exothermic carbonylation reaction, and where at least part of the heat obtained from the acetic acid is tapped from the first reaction zone and at least part of the heat tapped during production of acetic acid is transferred to a heat exchange system; (b) bringing the reaction stream of acetic acid containing at least a portion of acetic acid from the first stream of product into contact an oxygen-containing gas in a second reaction zone in the presence of a catalyst to obtain a second stream of product which contains vinyl acetate monomer; (c) directing at least a portion of the second stream of product to purification section for purification of at least a portion of vinyl acetate in the second stream of product; and either (d) tapping at least part of heat transferred to the heat exchange system, and delivering at least part of the heat tapped from the heat exchange system to at least one reaction stream of acetic acid and the vinyl acetate purification section, and where the heat exchange system contains a stream of a steam condensate, and where at least part of the heat tapped during production of acetic acid is delivered to the stream of steam condensate which is used to provide at least one reaction stream of acetic acid and the vinyl acetate purification section with heat tapped during production of acetic acid, where the stream of steam condensate containing heat from production of acetic acid is directed to a low-pressure evaporation vessel kept at pressure between 4.0 kg/cm2 and 5.3 kg/cm2, or (d) tapping at least part of the heat transferred to the heat exchange system, and delivering at least part of heat tapped from the heat exchange system to at least one reaction stream of acetic acid and the vinyl acetate purification section, in which a loop is used to cycle the condensate in order to remove most of the heat from production of acetic acid by directing a stream of a hot reaction solution through the heat exchanger for transferring heat to the stream of steam condensate, where the stream of steam condensate which contains heat from production of acetic acid is directed to the low-pressure evaporation vessel kept at pressure between 4.0 kg/cm2 and 5.3 kg/cm2.

EFFECT: proposed methods are useful for lowering expenses and reducing power consumption during vinyl acetate production.

10 cl, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: invention refers to mixed oxide catalysts for catalytic oxidation of olefins and methylated aromatic compounds in gas phase, to a method for preparing such catalysts and a method for making aldehydes and carboxylic acids. There are described mixed oxide catalysts of general formula I (Mo12BiaCb(Co+Ni)cDdEeFfGgHh)Ox (I), where C means iron, D means P, E means at least one of elements of the group including Li, K, Na, Rb, Cs, F means Mn, G means at least one of elements of the group including Sm, Gd, La, H means at least one of elements of the group including Si, Al, and a means a number 0 to 5.0, b means a number 0.5 to 5.0, c means a number 2 to 15, d means a number 0.01 to 5.0, e means a number 0.001 to 2, f means a number 0.001 to 5, g means a number 0 to 1.5, h means a number 0 to 800, and h means a number determined by the valence and concentration of the elements differing from oxygen. There is described a method for preparing a catalysts of formula (1), where solutions of the compounds found in mixed oxide catalysts of formula of I metals are mixed; cosediment are prepared; a formed solid substance is recovered, dried, baked and if necessary processed to shape as required. There is also described a method for making aldehydes and acids by air or oxygen oxidation of olefins or methylated aromatic compounds in the inert gas, steam or end reaction gas medium at higher temperatures with using described catalyst of general formula (1).

EFFECT: higher activity and selectivity of the catalyst.

25 cl, 14 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method for long-term heterogeneous catalytic partial gas-phase oxidation of an organic starting compound selected from propylene, isobutene, acrolein, methacrolein, propane or isobutane, to the desired organic compound, where the starting gaseous reaction mixture, containing the organic starting compound and molecular oxygen, is first passed through a freshly loaded sold catalyst layer which is filled with separation into two temperature zones A and B, lying in space one behind the other, temperature TA of which is such that the difference ΔTBA between temperature TB of zone B and temperature TA of zone A, which is calculated by taking the greater of the two values as the minuend, is greater than 0°C, such that the starting reaction mixture of gases successively flows through temperature zones A, B, first through A and then B, where temperature zone A extends until conversion of the organic starting compound UA = 15-85 mol %, and in temperature zone B conversion of the organic starting compound increases to a value UB ≥ 90 mol %, and as the operating life increases, temperature of zones A, B is changed in order to compensate for deterioration of quality of the solid catalyst layer, where as the duration of operation increases, temperature of that temperature zone which initially had a lower value, is raised, and the difference ΔTBA between temperature values of both zones is lowered, such that when calculating the difference, temperature of that zone which was initially the higher value, remains as the minuend.

EFFECT: compensating for the deterioration of quality of the solid catalyst layer with long operating life.

21 cl, 1 tbl

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