Method of continuous heterogeneously catalyzed partial dehydrogenation

FIELD: petrochemical process catalysts.

SUBSTANCE: reaction gas is passed in reaction zone through at least one fixed catalyst bed wherein reaction gas is subjected to dehydrogenation to produce molecular hydrogen and at least one dehydrogenated hydrocarbon. Reaction gas, before and/or after entering reaction zone, is supplemented by at least one molecular oxygen-containing gas, which partially oxidizes molecular hydrogen contained in reaction gas to form water steam. Gas product containing molecular hydrogen, water steam, at least one dehydrogenated hydrocarbon, and at least one hydrocarbon to be dehydrogenated is withdrawn from reaction zone, and divided into two parts, one of which is recycled into reaction zone.

EFFECT: simplified process and increased propylene formation selectivity.

12 cl, 2 dwg, 3 tbl, 4 ex

 

The invention relates to a continuous partial dehydrogenation in the heterogeneous catalysis of at least one subject to dehydrogenation of the hydrocarbon in the gas phase, in which

in the reaction zone continuously served the reaction gas, which contains at least one subject dehydrogenating a hydrocarbon,

- the reaction gas in the reaction zone is passed through at least one fixed catalyst bed, through catalytic dehydrogenation is formed molecular hydrogen and partially, at least one digidrirovanny hydrocarbon,

- in the reaction gas before and/or after introduction into the reaction zone serves at least one gas containing molecular oxygen,

- in the reaction zone with molecular oxygen partially oxidizes part of the reaction gas molecular hydrogen to water vapor and

- get a gas which contains molecular hydrogen, water vapor, at least one digidrirovanny hydrocarbon and at least one subject dehydrogenating hydrocarbons, is removed from the reaction zone.

In addition, the invention concerns a device for implementing the method according to the invention.

Used in this application the term "dehydrogenated hydrocarbons include acyclic and cyclic, aliphatic is such hydrocarbons with one or more C,C - double bonds in the molecule. Examples of such aliphatic hydrocarbon is propene, ISO-butene, 1-butene, 2-butene and butadiene. In other words to digidrirovanny hydrocarbons include, in particular, unsaturated linear (n-alkenes) or branched aliphatic hydrocarbons (for example, ISO-alkenes), as well as cycloalkene. In addition, dehydrogenated hydrocarbons also cover alopolaty (for example, diene or triene), the molecule of which has more than one double carbon-carbon linkages. They also include hydrocarbon compounds derived from alkyl aromatic hydrocarbons, such as atulananda or isopropylbenzene the dehydrogenation of alkyl substituents. They belong, for example, such compounds as styrene or α-methylsterol.

In General dehydrogenated hydrocarbons form a valuable starting compounds for the synthesis of, for example, amenable to radical polymerization compounds with functional groups (for example, acrylic acid from propene or methacrylic acid from isobutane) and their polymerization products. They are also suitable for the production of compounds such as simple methyl tert-butyl ether (product obtained from isobutene, which, for example, as a fuel additive can be used to increase the octane number). Degidio is installed hydrocarbons as such may also be used for polymerization.

It is well known that the dehydrogenated hydrocarbons receive continuous partial dehydration under heterogeneous catalysis to be the dehydrogenation of hydrocarbons in the gas phase (see, for example, DE-A 10028582, DE-AND 10047642, DE-A 19937107 and cited in these documents literary sources).

Thus as subject to dehydrogenation of hydrocarbons suitable in particular acyclic and cyclic alkanes and olefins (including C,C - double bonds which is necessary to enlarge) (an example is heterogeneously-catalyzed partial dehydrogenation of n-butenes to butadiene).

Thus, the notion of "subject to dehydrogenation of hydrocarbons" in this application includes features2-C16-alkanes, such as ethane, propane, n-butane, ISO-butane, n-pentane, ISO-pentane, n-hexane, n-heptane, n-octane, n-nonan, n-decane, n-undecane, n-dodecane, n-tridecane, n-tetradecane, n-pentadecane and n-hexadecane.

In particular, all available in this context statements relate to C2-C8-alkanes as eligible for the dehydrogenation of hydrocarbons and particularly preferably2-C4-hydrocarbons as eligible for the dehydrogenation of hydrocarbons.

In other words, subject to the dehydrogenation of hydrocarbons in this context are primarily ethane, propane, n-butane and ISO-butane and 1-butene and 2-the bout is called

Heterogeneously-catalyzed partial dehydrogenation subject to dehydrogenation of hydrocarbons requires a relatively high temperature reactions. Thus attainable degree of transformation, as a rule, is limited by thermodynamic equilibrium. Typical reaction temperatures are from 300 to 700°S. molecule negidrirovannogo hydrocarbon, usually get at least one hydrogen molecule.

In addition, typical for heterogeneously-catalyzed partial dehydrogenation subject to dehydrogenation of hydrocarbons is that it proceed endothermically. Therefore, the heat required to achieve the desired degree of conversion, you must submit to the reaction gas before and/or during the catalytic dehydrogenation.

In many known ways heterogeneously-catalyzed partial dehydrogenation subject to dehydrogenation of hydrocarbons to produce heat outside of the reactor and from the outside it is served in the reaction gas. But this process requires time-consuming concepts of reactor design and implementation of the method and, in particular, at high degrees of conversion leads to a sharp increase of the temperature gradients in the reactor, the disadvantage of which is the increase in the number of formed products.

Alternative heat of dehydrogenation m which can also be produced directly in the reaction gas by exothermic combustion is additionally supplied hydrogen or hydrogen, formed during the dehydrogenation, the supply of molecular oxygen with obtaining water vapor. To do this, in the reaction gas before and/or after introduction into the reaction zone of the catalyst dehydrogenation add oxygen-containing gas and, if necessary, hydrogen. Or the dehydrogenation catalyst (this applies to most of the dehydrogenation catalysts) and/or introduced additional oxidation catalysts generally facilitate the desired implementation of hydrogen oxidation (see DE-A 10028582). Released this hydrogen burning heat of reaction in favorable conditions provides the opportunity to completely abandon indirect heating of the reactor and, thus, to develop a relatively simple concept, the method and, if a high degree of conversion, to limit the formation of temperature gradients in the reactor.

Lack of means to directly generate heat by burning hydrogen in the reaction gas is, however, that they require the use of large quantities of additionally supplied molecular hydrogen, which is relatively expensive, or that the selectivity of the formation of negidrirovannogo hydrocarbon is not entirely satisfactory, since in used molecular oxygen only when in the moznosti access to hydrogen, which is formed during the heterogeneously-catalyzed partial dehydrogenation, constantly burns not only this molecular hydrogen, but also some amount subject to dehydration and/or already negidrirovannogo hydrocarbon, which is disadvantageous way lowers the selectivity of the target product.

The objective of the invention is to develop the first described method for continuous heterogeneously-catalyzed partial dehydrogenation of at least one subject to dehydrogenation of the hydrocarbon in the gas phase, which would no longer displayed and/or slightly showed the disadvantages indicated above.

According to this, developed a method for continuous heterogeneously-catalyzed partial dehydrogenation of at least one subject to dehydrogenation of the hydrocarbon in the gas phase, in which

in the reaction zone continuously served the reaction gas, which contains at least one subject dehydrogenating a hydrocarbon,

- the reaction gas in the reaction zone is passed through at least one fixed catalyst bed, through catalytic dehydrogenation is formed molecular hydrogen and partially, at least one digidrirovanny hydrocarbon,

- in the reaction gas before and/or after the introduction of in re Klenow area served, at least one gas containing molecular oxygen,

- in the reaction zone with molecular oxygen to partially oxidize molecular hydrogen, which is part of the reaction gas to produce steam and

- get a gas which contains molecular hydrogen, water vapor, at least one digidrirovanny hydrocarbon and at least one subject dehydrogenating hydrocarbons, is removed from the reaction zone, which is characterized by the fact that derived from the reaction zone, the product gas is divided into two portions of identical composition and one of the two parts as circulating gas recycle to the reaction zone.

The method according to the invention is particularly suitable for heterogeneously-catalyzed partial dehydrogenation of propane to obtain propene, butane to butene and/or butadiene, and butenes to obtain butadiene.

It differs from the catalytic oxidisation hydrocarbons in particular the fact that when the catalytic oxidisation does not form hydrogen. Instead, the hydrogen, which otscheplaut from subject to dehydrogenation of the hydrocarbon otscheplaut directly as water (H2About). This usually requires different reaction conditions, and other catalysts.

Mainly for implementing the method according to the invention can be COI is used all dehydrogenation catalysts, it was recommended in the prior art for implementing heterogeneous-catalyzed partial dehydrogenation subject to dehydrogenation of hydrocarbons in the gas phase in the formation of molecular hydrogen.

Roughly they can be divided into two groups. Namely, the oxide catalysts of the character (for example, chromium oxide and/or aluminum oxide) and those which consist of at least one, usually a relatively noble metal (e.g. platinum)deposited on typically the oxide carrier. According to the invention is preferred dehydrogenation catalyst based Lewis acids, which generally do not have the acidity Branstad described in DE-A 10047642.

Thus, suitable are in particular all dehydrogenation catalysts described in DE-A 10060099 (sample run), WO 99/46039, US-A 4788371, EP-A, der WO 99/29420, US-A 5220091, US-A 5,430,220, US-A 5877369, EP-A 117146, DE-A 19937106, DE-A 19937105, DE-A 10047642, and also DE-A 19937107.

In particular, for the implementation of all the methods described in this text variants of the method according to the invention can be used as catalysts of example 1 and example 2, and example 3 and example 4 of the application DE-A 19937107.

When it comes to the dehydrogenation catalysts which contain from 10 to 99.9 wt.% zirconium dioxide, from 0 to 60 wt.% aluminum oxide, silicon oxide and/and the and of titanium dioxide and from 0.1 to 10 wt.%, at least one element of the first or second main group, one element of the third subgroup, one element of the eighth subgroup of the Periodic system of the elements, lanthanum and/or tin, provided that the sum of the weight percent amounts to 100 wt.%.

The implementation of the method according to the invention which is in a solid state catalyst selective effect is due to the fact that the dehydrogenation (cleavage of C-H) compared with cracking (splitting of C-C) is kinetically unfavorable. Due catalysts selective actions with the exclusion of oxygen at temperatures from 300 to 700°With (for example, when 600° (C) demonstrate considerable dehydration (in the case of propane as subject to dehydrogenation of the hydrocarbon yield of propylene with the catalyst loading propane, for example, 1000 hours-1is at least 30 mol-% for a single pass (in terms of used propane)), produces by-products such as methane, ethylene and ethane in only trace amounts.

At least one required according to the invention a stationary catalyst bed may contain a catalyst for the dehydrogenation of various geometric shapes. For implementing the method according to the invention are suitable, for example, such geometric shapes as small y is Ben, tablets, monoliths, spherical bodies or extrudates (harnesses, wheels, stars, rings). In the case of extrudates their length is from 2 to 15 mm, frequently from 2 to 10 mm, usually from 6 to 10 mm, the diameter of the cross-section of the extrudate is from 1 to 5 mm, frequently from 1 to 3 mm In the case of rings, the thickness is preferably from 0.3 to 2.5 mm, their length is from 2 to 15 mm, frequently from 5 to 15 mm, and the diameter of the cross section from 3 to 10 mm. Suitable method of molding is described, for example, in DE-A 10047642, and also in DE-A 19937107. It is based on the fact that the native oxide, mixed with a concentrated mineral acid (e.g. concentrated nitric acid), relatively well molded and using the extruder or plunger of the press can be converted into the corresponding molded product.

Thereafter, the molded product is dried, calicivirus, and then in sequence pour salt solutions. In closing them again dried and calicivirus.

In further describing in detail the preferred method of dehydrogenation of propane. The described method is likewise suitable for other subject to dehydrogenation of hydrocarbons.

Important for implementing the method according to the invention, the reaction zone can be implemented in all the C of the prior art types of reactors for heterogeneously-catalyzed partial dehydrogenation of hydrocarbons in the gas phase to the stationary layers of catalysts. Typical reaction temperatures are in the range from 200 to 800°and it is from 400 to 650°C. the Working pressure is generally from 0.5 to 10 bar. A typical load of catalyst, the reaction gas is from 300 to 16,000 hours.-1.

Detail appropriate types of catalysts are described, for example, in the publication "Catalytica® Studies Division, Oxidative Dehydrogenation and Alternative Dehydrogenation Processes, Study Number 4192 OD, 1993, 430 Ferguson Drive, Mountain View, California, 94043-5272 U.S.A.".

A suitable form of the reactor is a tubular reactor with a stationary layer or shell-and-tube reactor. When using these reactors, the catalyst dehydrogenation (and, if necessary, a specific catalyst for the oxidation of hydrogen, for example described in documents US-A 4788371, US-A 4886928, US-A 5430209, US-A 55530171, US-A 5527979, US-A 5563314 and EP-A 832056) as a stationary layer is in the reaction tube or in reaction sections. Reaction tubes, usually heated by burning gas, for example, hydrocarbons, such as methane, in the space surrounding the reaction tubes. Best was the use of such forms of indirect heating around the first 20-30% of the backfill stationary layer and heating the remainder of the backfill to a certain reaction temperature released within the combustion radiant warmth. Indirect heating of the reaction gas according to the invention advantageous the way combined with direct heating by combustion with molecular oxygen in the reaction gas.

Thanks to this combination of direct introduction of heat according to the invention with indirect introduction of heat in a relatively simple form, you can achieve isothermal implementation of the response.

The normal inner diameter of the reaction tubes is approximately 10 to 15 cm of a Typical shell-and-tube reactor for the dehydrogenation contains from about 300 to 1000 reaction tubes. The temperature inside the reaction pipe ranges from 300 to 700°C, preferably from 400 to 700°C. the Working pressure is usually from 0.5 to 8 bar, frequently from 1 to 2 bar or 3 to 8 bar. As a rule, at the outlet of the reaction tube and the reaction zone the temperature of the reaction gas is different (higher or lower) from the temperature at the inlet (see also US-A 4902849, US-A 4996387 and US-A 5389342). Typical loading of the catalyst is subjected to a dehydrogenating a hydrocarbon, such as propane, range from 500 to 2000 h-1(=nl/l of catalyst/hour).

Of course, the method according to the invention can be carried out in a reactor with a moving bed (unlike fluidized bed moving layer in this text should also be considered as a stationary layer). Such a moving layer of the dehydrogenation catalyst may be, for example, placed in the reactor with radial movement of the thread. In it the catalyst moves slowly from the top down, that is W hen the reaction gas flows radially. It is reasonable to exploit several serially connected reactors, moving bed. In this case, before each reactor in the reaction gas supply gas containing molecular oxygen, the combustion of which heats the appropriate reactor to the reaction temperature.

Depending on which of leaving one of the serially connected reactors, the gas flow according to the invention is divided into two parts, and in which the reactor recycle one of the parts corresponding to the reaction zone according to the invention may include all or only a portion (for example, each reactor itself) serially connected reactors. If, for example, use four serially connected reactor and received from the fourth reactor gas according to the invention is divided into two parts and one of the two parts recycle in the first of connected reactors, the reaction zone according to the invention includes all four reactors. If according to the invention in two parts divide only the gas obtained from one of the first serially connected reactors, and one of the two parts recycle in the first reactor, the reaction zone according to the invention includes only the first reactor.

The dehydrogenation catalysts used according to the invention for the reactor is moving layer, it is advisable to have a spherical shape. Working pressure typically ranges from 2 to 5 bar. The reaction temperature usually ranges from 550 to 660°C. In this case, as in the case of other suitable reactors for the implementation described in this application means according to the invention, the catalyst may be filled with a mixture of catalysts for dehydrogenation and H2-oxidation, as described, for example, in EP-A 832056.

According to another form of execution of the method according to the invention heterogeneously-catalyzed dehydrogenation is carried out in a lattice reactor. It contains one or more consecutive layers of catalyst. The number of layers can be from 1 to 20, preferably from 2 to 8, in particular from 4 to 6. The reaction gas flows through the catalyst bed preferably radially or axially.

In the simplest case, the fixed catalyst layers placed axially in the reactor in the form of a shaft furnace or in the annular gaps of concentric spaced each other cylindrical grate. Thus, the method according to the invention may be carried out in a separate reactor in the form of a shaft furnace.

If in the process according to the invention in the reaction gas before and/or after entry into the reaction zone did not add gas containing mole is ularly oxygen, the reaction gas is distributed within the reactor on the way from one catalyst to another should be subjected to intermediate heating, for example, by passing through heated by hot gases fin heat exchangers or by passing through the heated hot combustible gases pipe.

In the framework of the method according to the invention described above, the intermediate heating is carried out, at least partially, direct way. With this objective, the reaction gas immediately before passing through the first catalyst bed and/or between subsequent catalyst layers in a limited number of add gas containing molecular oxygen.

At least one, if necessary, on all layers of the catalyst is burned filed in limited quantities before the reaction gas and/or formed during dehydrogenation of molecular hydrogen. The heat which is thus freed, provides autothermal implementation of heterogeneously-catalyzed dehydrogenation of a hydrocarbon according to the invention.

According to another form of execution of the invention produce an intermediate supply of oxygen-containing gas, if necessary, before each lattice lattice reactor. The following form of the method according to the invention under the Chu oxygen-containing gas is carried out before each lattice except the first. In another form of the method according to the invention for each oxygen is backfilling of specific suitable for the oxidation of H2oxidation catalyst, which is the filling of the dehydrogenation catalyst. If necessary, before each grille can additionally present the external molecular hydrogen.

Essential according to the invention is that when carrying out the method there is no need to supply external molecular hydrogen (under it should be understood molecular hydrogen, which is not part recycled to the reaction zone of the circulating gas and of itself is not formed in the reaction zone).

The temperature of the dehydrogenation in lattice reactor is generally from 400 to 800°With pressure - mainly from 0.2 to 10 bar, preferably from 0.5 to 4 bar and particularly preferably from 1 to 2 bar. Total load gas is generally from 500 to 2000 h-1under high load also up to 16000 h-1mainly from 4000 to 16000 h-1.

In the process according to the invention due to the dehydrogenation of hydrocarbons should not be pure substances. Moreover, be used for the dehydrogenation of raw hydrocarbon may contain other daydreamy gases. In case the e use of propane they can be methane, ethane, ethylene, propene, butane, butenes, acetylene, H2S or pentane.

The gas, which in the framework of the method according to the invention must be submitted in the reaction gas before and/or after introduction into the reaction zone and which contains molecular oxygen, can be a pure molecular oxygen or a mixture with inert gases, such as CO2N2or noble gases. As a gas containing molecular oxygen, mainly use the air.

Accordingly, in the framework of the method according to the invention in the reaction zone serves, if necessary, external molecular hydrogen in pure form or in a form diluted with an inert gas.

Because the partial dehydrogenation in the heterogeneous catalysis of at least one subject to dehydrogenation of a hydrocarbon according to the invention occurs with increasing volume, the degree of conversion can be increased by reducing the partial pressure of the reactants. This can be achieved in a simple way, for example, by dehydrogenation under reduced pressure and/or by contact with an inert gas, that is why the above inert gases are desirable in the implementation of the method according to the invention.

As mentioned above, suitable for implementing the method according to the invention is the tsya inert gases, for example, nitrogen, water vapor, carbon dioxide and noble gases such as No, Ne or Ar. Preferred inert diluents are those which under the reaction conditions in the process according to the invention are subjected to chemical change by less than 5 mol-%, preferably less than 3 mol-% and more preferably less than 1 mol-%. All of these diluents when carrying out the method according to the invention can be used in pure form or in the form of various mixtures. As gaseous diluents can also be used gases, which under the above boundary conditions quickly become exothermic reaction with molecular oxygen than at least one digidrirovanny and/or subject to dehydrogenation of hydrocarbons.

In principle, the method according to the invention can also be carried out without the presence of an inert, current dilution gases. In other words, the methods according to the invention are also those in which the reaction gas supplied to the reaction zone, consists exclusively of at least one subject to dehydrogenation of hydrocarbons. In this case, the required gas, which according to the invention contains molecular oxygen, first served along the reaction path reaction zone. According to the invention of his mo is but also to serve until the introduction of the reaction gas in the reaction zone. In these cases, the reaction gas may comprise at least one subject dehydrogenating hydrocarbon and only molecular oxygen or molecular oxygen and one or more inert gases. Of course, in the implementation of the method according to the invention, a gas containing molecular oxygen, can be fed into the reaction gas to the inlet of the reaction gas in the reaction zone, and along the reaction path reaction zone.

According to the invention preference is given to the way in which the total amount of gas containing molecular oxygen, is fed into the reaction gas before entry into the reaction zone. When this has set, what is the best method according to the invention, in the exercise of which, either before entry into the reaction zone, or along the reaction path does not serve external molecular hydrogen.

Typically, the amount of molecular oxygen supplied to the reaction gas before entry into the reaction zone, is (in terms of the total number subject to dehydrogenation of a hydrocarbon, such as propane) from 0.001 to 0.5 mol/mol, preferably 0.005 to 0.2 mol/mol and particularly preferably from 0.05 to 0.2 mol/mol. A higher ratio is used preferably for large quantities of propane. According to the invention the number entered in reacts the traditional gas molecular oxygen is calculated based on the production amount of heat, required along the reaction path for heterogeneously-catalyzed dehydrogenation of at least one hydrocarbon, through the combustion of molecular hydrogen. In a special form of heat obtained from the combustion of molecular hydrogen, molecular oxygen may be greater or less than the heat required for the dehydrogenation of hydrocarbons.

According to the invention in the reaction gas is fed total number of required inert gas (excluding inert gas formed in the reaction zone when carrying out chemical reactions) before entering the reaction zone. In other words, according to the invention the intermediate feeding an inert gas is not carried out.

In the process according to the invention in an inert gas diluent use water vapor. Water vapor in addition to the activity of the diluent reduces the coking used in the method according to the invention catalysts, because water vapor is usually reacts with the thus formed coke on the principle of coal gasification.

According to the invention preferably does not perform an interim supply of water vapor and the reaction gas before entry into the reaction zone at one time served the required amount of water vapor. The ratio of water vapor and at least one subject of digid is the licensing of hydrocarbon in the reaction gas before entry into the reaction zone is generally from 0 to 10 mol/mol, often from 0.1 to 10 mol/mol, and preferably from 0.1 to 5 mol/mol.

Because the necessary molecular oxygen in the framework of the method according to the invention is usually served as part of the air, the reaction gas before entry into the reaction zone in an inert gas diluent is usually also contains molecular nitrogen.

In other words, by implementing the method according to the invention is supplied into the reaction zone of the reaction gas, which typically contains water vapour and nitrogen as the inert gaseous diluents.

A distinctive feature of the method according to the invention is that derived from the reaction zone resulting gas containing molecular hydrogen, water vapor, at least one subject dehydrogenating a hydrocarbon and at least one digidrirovanny hydrocarbon, is divided into two portions of identical composition and one of the two parts of the reaction gas recycle to the reaction zone. Such recirculation may be effected in the form of interim supply, and with the introduction of the reaction gas in the reaction zone. Preferably according to the invention the feed is carried out exclusively with the introduction of the reaction gas in the reaction zone. Himself the reaction gas is usually injected into the reaction zone in one place, instead of using additional interim filings.

The amount of p is given in the reaction zone of the reaction gas and recycle gas, recirculated to the inlet of the reaction gas in the reaction zone, in this context, it should be marked as bootable gas.

The advantage of the method according to the invention is that the gas flow is recirculated to the reaction zone contains an educated already in the process of heterogeneous-catalyzed partial dehydrogenation of molecular hydrogen, which allows for the implementation of the method according to the invention to completely abandon the use of external hydrogen and still achieve the advantages of burning hydrogen. Especially if the circulation gas is returned to the reaction zone, is part of the boot gas loading the gas from the outset contains required for combustion of molecular hydrogen, originating from expensive external source.

Combustion in a circulating gas of molecular hydrogen leads to the removal of hydrogen from the equilibrium dehydrogenation that under similar conditions promotes thermodynamically possible transformations. In addition, using the circulating gas recirculation according to the invention increases the selectivity of the formation of negidrirovannogo hydrocarbon. This especially occurs when the subject under dehydrogenating hydrocarbon imply propane Reason for this selectivity enhancement should be the fact, what is recycled into the reaction zone in the composition of the circulating gas once digidrirovanny hydrocarbon unexpectedly behaves inertly with respect to the desired relatively specific process for the catalytic dehydrogenation, as well as the relatively hydrogen burning.

According to the invention in the reaction zone usually recycle at least 10% or 20% taken from the reaction zone of the gas. Preferably the amount withdrawn from the reaction zone of the gas recycled to the reaction zone as a circulating gas is not more than 90% or 80%. In other words, the amount returned to the reaction zone as a circulating gas, withdrawn from the reaction zone of the gas in the process according to the invention can be, for example, from 20 to 80%, or from 30 to 70%, or from 40 to 60% or 50% of the quantity of gas taken. Particular preference is given to quantitative indicators from 50 to 70%.

If in the method according to the invention, the reaction gas and the circulating gas supplied to the reaction zone only in one place so that the boot gas contains filed in the reaction zone, the amount of molecular oxygen and molecular hydrogen, the choice of a suitable molar ratio of molecular oxygen to molecular hydrogen in the boot g the se according to the invention it is possible to perform the process heterogeneously-catalyzed partial dehydrogenation, at least one subject to dehydrogenation of a hydrocarbon, in terms of a single passage of the mixture bootable gas through the reaction zone, as endothermic, autothermal (total reaction enthalpy of the reaction zone is basically zero)and exothermic by. Preferred autothermal or slightly exothermic process. In this case, the best molar ratio in the boot gas molecular oxygen in the boot gas molecular hydrogen is 1:1 or less, preferably 1:2 or less. If this ratio is more than 1:2, and the number extracted from the reaction zone of the gas used as the circulating gas is over 90%, thermodynamic control of heterogeneously-catalyzed partial dehydrogenation according to the invention mainly will be removed and you can achieve a conversion of from 80 to 90 mol-%, in terms of a single pass of the reaction gas. The overall reaction, as a rule, carry out exothermic by.

If necessary, prior to introduction into the reaction zone of the boot, the gas can be preheated.

Without special measures, the method according to the invention can be implemented in such a way that in a single pass of the reaction gas through react the traditional zone conversion subject to dehydrogenation of a hydrocarbon (for example, propane or butane) is ≥5 mol-% to ≤70 mol-%.

The choice of conversion depends especially on the further application of the part extracted from the reaction zone a gas that does not recycle to the reaction zone as a circulating gas. This product can be recycled, for example, in a known manner: the contained non-hydrocarbon components are separated, for example by selective absorption of hydrocarbons in the organic solvent, as described, for example, in DE-a 10028582, and/or by distillation, and the remaining mixture from the subject to the dehydrogenation of hydrocarbons and negidrirovannogo hydrocarbons are separated in the separator (for example, in the case of propane, used as subject dehydrogenating hydrocarbon), and the part subject to the dehydrogenation of hydrocarbons as an integral part of the reaction gas is again fed to the dehydrogenation, while separated digidrirovanny hydrocarbon is subjected to further transformation. In this case, the method according to the invention it is expedient to perform at a higher conversion of hydrocarbons (typically from 35 to 60 mol-%).

Often the method according to the invention is combined with the method of obtaining the products of partial oxidation and/or products of partial Immokalee or the method of obtaining the products of alkylation, Addu is tov the Diels-alder reaction, products oxychlorination process and products of the metathesis of at least one extracted from the reaction zone, obtained according to the invention gas containing digidrirovanny hydrocarbon (e.g. propane or ISO-butene), as recommended in US-A 3161670, EP-A, DE-AND 3313573, DE-A 10028582, as well as in DE-a 10131297 or in DE-a 10148575, DE-A 10148577, DE-A 10206954, DE-A 10159615, DE-A 10118634, DE-AND 10130958 and DE-A 10160726. In these cases, the conversion in the process of dehydrogenation according to the invention ranges from ≥5 mol-% to ≤30 mol-% or ≤25 mol-%, often about 20 mol-%. Under the "ammatillinen" refers to the reaction of oxidative ammonolysis in the presence of ammonia and oxygen.

For this purpose, a certain number (a mixture gas obtained And extracted from the reaction zone in the process according to the invention the gas that is not recycled into the reaction zone, and a certain number of contained components that is different from at least one subject dehydrogenating hydrocarbons (such as propane, n-butane or ISO-butane) and from at least one negidrirovannogo hydrocarbons (such as propane, n-butene or ISO-butene), if necessary, in the separation zone to separate a part or the whole mass in the mixture the obtained gas And' and the mixture obtained gas or a mixture gas obtained As' COI is lsout to download one of these subsequent reactions, and also, for example, heterogeneously-catalyzed oxidation zone and/or Immokalee, which contained at least one digidrirovanny hydrocarbon, for example, is subjected to partial oxidation and/or amoxiline molecular oxygen in the formation of a mixture gas obtained In which both the target product contains at least one oxidation product and/or amoxiline (for example, acrylic acid, methacrylic acid, acrolein, Acrylonitrile, etc.)at least one negidrirovannogo hydrocarbon.

Then in the treatment area With a mixture of the obtained product is separated target product and at least one part of at least one not converted, subject to dehydrogenation of a hydrocarbon, which is part of the residual mixture obtained gas as a component of the second circulating gas recycle to the reaction zone dehydrogenation according to the invention as a source of reactive gas.

This second circulating gas, usually along with the subject dehydrogenating hydrocarbons often also contains inert and/or aenertia gases

- thinners, such as methane, ethane, ethylene, and higher hydrocarbons, water vapor, N2, CO, CO2and, if necessary, molecular oxygen.

With this combining method according to the invention heterogene-catalyzed partial oxidation and/or amoxilina, at least one negidrirovannogo hydrocarbon preferably, the method of oxidation and/or amoxiline carried out with the use of excessive amounts of molecular oxygen in terms of the stoichiometry of the oxidation and/or Immokalee. In the area of work so that an excessive amount of molecular oxygen in the second circulation gas mainly remains. The second circulating gas containing the molecular oxygen as a component of the reaction gas in the process according to the invention can be a source (preferably only source) is required molecular oxygen. The above is particularly the case if you want to dehydrogenation of the hydrocarbon is propane and the product of the partial oxidation negidrirovannogo hydrocarbon of propene - acrolein and/or acrylic acid.

If the second circulating gas is returned to the reaction zone according to the invention and containing molecular oxygen, also contains CO, oxidizing agents, such as, for example, acrolein, acrylic acid, formaldehyde, acetic acid and/or ethylene oxide, to entry into the reaction zone and/or in the reaction zone, also in the heterogeneous catalysis, can be subjected to oxidation by molecular oxygen with the receipt, such as CO 2and H2O. Freed when this heat can be used for heating the reaction gas.

The reaction zone method according to the invention preferably includes only a single filling of the catalyst, and the catalyst used, the catalyst according to example 1 or according to example 2 or according to example 3 or according to example 4 of the application DE-A 19937107, or according to the exemplary embodiment of the application DE-A 10060099.

If as subject to dehydrogenation of hydrocarbons using propane, and as negidrirovannogo hydrocarbon - propene, the mixture bootable gas may have the following composition:

a) 50-70% extracted from the reaction zone (dehydrogenation) of gas (the first circulating gas).

This gas usually consists of the following components:

0-1% vol. methane0-60% vol. H2O
0-1% vol. ethane,0-1% vol. With4+-carbon
0-1% vol. Atena,0-2% vol. CO2,
1-10 vol.% H2,0-2% vol. O2,
1-20 vol.% of propene,10-40 vol.% propane,
0-1% vol. WITH,the remainder to 100%: mainly nitrogen.

b) the second circulating gas, which is produced by heterogeneously-catalyzed partial oxidation to and the of rolein and/or acrylic acid part of the gas, containing propene, extracted from the reaction dehydrogenation zone and returned it in an indirect way; this second circulating gas usually consists of the following components:

0-1% vol. methane0-1% vol. WITH,
0-5% vol. H2O0-3 vol.% CO2,
0-1% vol. Atena,0-10% vol. O2,
0-1% vol. ethane,10-40 vol.% propane,
0-1% vol. hydrogen0-1% vol. With4+hydrocarbons
0-1% vol. of propene,the remainder to 100%: mainly nitrogen.

C) fresh propane and fresh water vapor.

According to the invention the supply of other gases in the reaction zone is not required.

The ratio of the volumes are:

the first circulating gas:the second circulating gas:fresh propane:fresh water vapor =10-30:10-30:1:0.1 to 5.

Preferably, the specified ratio is 20:20:1:1. Thus heterogeneously-catalyzed dehydrogenation carried out mainly by autothermal at a temperature of from 450°650°and a pressure of from 1 bar to 3 bar. Load dehydrogenation catalyst loading gas ranges from 2000 to 20000 nl/l cat./hour.

The preferred forms of the catalysts are the wiring length from 2 to 10 mm and diam is the centre of the cross section from 1 mm to 4 mm

The used catalyst may be regenerated, as described in DE-a 10028582. When expressed decontamination process of regeneration can be performed several times to restore the initial performance. The regeneration process includes a step of regeneration of pure molecular hydrogen or molecular hydrogen diluted with an inert gas. To limit the amount of hydrogen required for the implementation of this stage of regeneration, regenerating the hydrogen is advisable to run in a loop or the preferred way for a long time to leave over the deactivated catalyst. As the dehydrogenation reactor may be used a simple shaft reactor. Partial oxidation can be carried out by the methods described in the documents cited in the prior art (in particular DE-A 10311297 and DE-10028582). When obtained from a mixture of gas And before it can be used for partial oxidation is preferably emit all other than propane and propene components.

In the method according to the invention the return of the circulating gas in the reaction zone is carried out using the compressor outside the reaction zone.

In a particularly preferred form of the circulating gas is carried out in a reactor with circulation of the reaction mixture containing jets the first pump.

This reactor contains a catalyst loading and at least one jet pump (figure 1 schematically shows the jet pump). The latter consists of a jet nozzle (1), the mixing tube (2), diffuser (3) and a suction pipe (4). The numbers in brackets refer to figure 1.

Using the jet nozzle in the direction of flow in the mixing tube direct the jet stream. Consequently, in the suction nozzle establishes a low pressure, which absorbed the surrounding pipe gas while mixing with the jet stream is transported through the mixing tube through the diffuser and is available. Jet-stream in the process according to the invention is formed using supplied into the reaction zone of the reaction gas. For the diffuser flow direction change in the opposite direction and the catalyst loading, the reaction gas. Part of leaving the catalyst reaction gas is partially absorbed suction inlet in the mixing pipe is mixed with the reaction gas and as a mixture of boot gas is released through the diffuser. The residual amount of gas discharged from the reactor. Used in this context, the concept of the jet pump also includes an ejector jet nozzle. An example of a reactor design with circulatie the reaction mixture, containing the jet pump shown in figure 2. In the figure 2 digital positions have the following meanings:

1 means the layer of catalyst; 2 means, for example, propane; 3 means, for example, air; 4 means, for example, water vapor; 5 - obtained gas; 6 - jet pump.

When it comes to the reactor with circulation of the reaction mixture containing the jet pump of this type, in which on one side of the loading of the catalyst is suction nozzle, and on the other side of the cone. When using jet pumps located inside the reactor, the pump suction is performed with the possibility of locking. It may be of advantage particularly in the case of regenerations of the catalyst. With the regenerating gas jet stream is formed, at that time, as the suction nozzle is in the closed state. It can also be opened. Needless to say, at least one jet pump reactor with circulation of the reaction mixture may also be located outside of the reactor containing the catalyst loading. Another advantage of the method according to the invention consists in increasing the duration of the loading of the catalyst compared to a method without implementation of the recirculation circulating gas in the reaction zone.

Examples and comparative approx the market

1. Preparation of a dehydrogenation reactor

1000 g of crushed mixed oxide ZrO2/SiO2pour the solution 11,993 g SnCl2/2H2O and 7,886 g H2PtCl6/6H2O in 600 ml of ethanol.

The ratio of ZrO2/SiO2in the mixed oxide is 95:5. The manufacturer of the mixed oxide firm Norton (USA).

Mixed oxide has the following characteristics: type AXZ 311070306, series No. 2000160042, mesh fraction: 1.6 to 2 mm, WET-surface: 86 m2/g, pore volume: of 0.28 ml/g (measured Parametrii mercury).

Located on top of the ethanol is removed by rotation in a rotary evaporator in a water-jet pump vacuum (20 mbar) at a temperature of the water bath 40°C. Then the reaction mixture is dried in still air at a temperature of 100°C for 15 hours and then at a temperature of 560°calicivirus for 3 hours. After this dried solid is watered with a solution 7,71 g CsNO3, 13,559 g KNO3and 98,33 g La(NO3)3/6H2O in 2500 ml of H2O. above the amount of water removed by rotation in a rotary evaporator in a water-jet pump vacuum (20 mbar) at a water temperature of 85°C. Then the reaction mixture is dried in still air at a temperature of 100°C for 15 hours and then at a temperature of 560°calicivirus within 3 hours.

Obtained is in this way, the catalyst precursor has a composition Pt for 0.3Snfor 0.6Cs0,5To0,5La3,0(weight ratio) (ZrO2)95/(SiO2)5(weight ratio).

Vertically positioned tubular reactor load 20 ml of the obtained formatilization (the length of the reactor: 800 mm; wall thickness: 2 mm; inner diameter: 20 mm; the material of reactor: aluminized inside (that is covered with aluminum oxide) steel pipe; heating: electric (stove company NTM Reetz, LOBA 1100-28-650-2) on the axial length of 650 mm; length backfill catalyst: 75 mm; the position of the filling of the catalyst: in the center of the axial length of the tubular reactor; filling the remaining portion of the reactor up and down steatite spherical shape (inert material) with a diameter of 4-5 mm from the bottom heating at the contact of the intermediate support).

Then in the reaction tube when the temperature of the outer wall along the heating zone 500°With (in terms of tube through which flows a stream of identical inert gas) within 30 minutes load of 9.3 nl/h of hydrogen. Thereafter, the flow of hydrogen at constant wall temperature for 30 minutes to replace 23,6 nl/h flow of 80% vol. nitrogen and 20% vol. air, then within 30 minutes - identical stream of clean air. At the same temperature of the wall is washed for 15 minutes in the same thread N2and then again within 30 minutes vosstanovlyu who have 9,3 nl/h of hydrogen. This completes the activation of the catalyst precursor.

2. Comparative example 1

Prepared as described in example 1, the dehydrogenation reactor at the same temperature control (500°With the wall temperature in terms of flowing inert gas as the reaction gas serves a mixture of 20 nl/h of raw propane and 20 g/h of water vapor. This crude propane type with flow regulator company Brooks, while water using HPLC pump 420 company Kontron first in liquid form is fed into the evaporator, it is vaporized and then mixed with the crude propane. The temperature of the reaction gas is 150°C.

Via the reactor outlet pressure regulator (REKO) set the output pressure of the rector, which is 1.5 abs. bar.

The resulting gas is cooled by reducing the pressure to normal, and the contained water vapor condense. The unfused residue gas analyzed by chromatography GC (HP 6890 with chem-station detectors: FID, WLD, separation columns: Al2About3/KCl (Chrompack), Car-boxen 1010 (Supeico)). Accordingly analyze also the reaction gas.

In the following table 1 shows some results depending on the duration of the reaction. Indicators in% vol. refer to "dry" the calculated gas is, that is, the amount of water vapor contained in all cases not taken into account.

Table 1
The reaction gas, vol.%The resulting gas (after 1 hour), vol.%The resulting gas (9 hours), vol.%
Propane99,9964,2562,81
Propene0,009616,6116,49
H2018,7420,33
O2000
N200,0680,065
Methane00,0400,033
Ethan0,0017amount of 0.118to 0.108
Eten00,0190,019
CO00,0190,014
CO200,1290,124

These indicators corresponds to 20.8 mol-% conversion of propane conversion on single pass of the reaction gas and the selectivity of the formation of propene of 99.1 mol-%.

Comparative example 2

While respecting the boundary conditions will compare the high of example 1 into the reaction gas is fed additional 7.5 nl/h of air and conduct the test. Download catalyst layer propane corresponds to the load of the comparative example 1. In the following table 2 shows some results depending on the duration of response (time from the transition to the new reaction conditions). Indicators in% vol. refer to "dry" it is estimated gas.

Table 2
The reaction gas, vol.%The resulting gas (after 3 hours), vol.%The resulting gas (20 hours), vol.%
Propane73,1645,4346,49
Propene0,00714,4014,03
H2017,5617,01
O25,3400
N221,5019,2818,97
Methane00,160,24
Ethan0,00120,200,22
Eten00,050,07
CO00,160,16
CO202,772,81

Comparison with what ublica 1 shows the presence of atmospheric oxygen contributes to a higher level of education COxand increase the formation of cracking products (methane, ethane and Aten). Both indicators are saying about the reduced selectivity of formation of propene. When the conversion of propane to 24.6 mol-%, in terms of a single pass of the reaction gas, the selectivity is 91,4 mol-%.

An example implementation

While respecting the boundary conditions of comparative example 2 422 l/h cooled to 150°With the reaction gas is returned back to the reactor inlet (using a membrane compressor company KNF Neuberger, press. 1.5 bar) and there is mixed with a reaction gas of comparative example 2 to obtain supplied to the catalyst filling the boot of gas. The adjustment of the quantity of the circulating gas is realized by means connected with the membrane compressor diaphragm (Rosemount, iris diameter: 1.3 mm). To avoid condensation of water diaphragm compressor, the aperture and the pipeline for circulating gas through the ribbon heater is heated to 150°C. Load propane corresponds to the load according to comparative example 2. A portion of the gas that is not recycled into the reaction zone, analyzed as described above. Table 3 shows the results obtained depending on the duration of the reaction is AI (the time from the transition to the new reaction conditions). Indicators in% vol. touch dry counted" gas.

Table 3
Boot gas, vol.%The resulting gas (after 3 hours), vol.%The resulting gas (20 hours), vol.%
Propane73,0860,1557,97
Propene0,00713,1014,51
H20are 5.366,94
O2are 5.3600
N221,5520,7319.93 per
Methane00,040,04
Ethan0,00090,120,13
Eten00,120,11
CO00,010,02
CO200,370,36

Comparing table 3 with table 2 shows that when the process with a circulating gas according to the invention increase the level of education COxdue to the air flow, and the formation of cracking products (methane, ethane and eaten) in terms of namolocheny propane approaching level the appropriate level of comparative example 1, which is carried out without oxygen. This indicates an increase of the selectivity of formation of propene compared with comparative example 2. In addition, the numeric values of hydrogen content compared with table 2 indicate that the recycled hydrogen is selectively oxidized with oxygen in the air. When the conversion of propane 20.3 mol-%, in terms of a single passage of the gas, the selectivity of the formation of propene was 98.0 mol-%.

1. Method for continuous heterogeneously-catalyzed partial dehydrogenation of at least one subject to dehydrogenation of the hydrocarbon in the gas phase, in which

in the reaction zone continuously served the reaction gas, which contains at least one subject dehydrogenating a hydrocarbon,

the reaction gas in the reaction zone is passed through at least one fixed catalyst bed, through catalytic dehydrogenation is formed molecular hydrogen and partially, at least one digidrirovanny hydrocarbon,

in the reaction gas before and/or after entry into the reaction zone serves at least one gas containing molecular oxygen,

in the reaction zone with molecular oxygen partially oxidizes in odasi in the composition of the reaction gas molecular hydrogen to water vapor and

gas product, which contains molecular hydrogen, water vapor, at least one digidrirovanny hydrocarbon and at least one subject dehydrogenating hydrocarbons, is removed from the reaction zone, characterized in that the output from the reaction zone of the gas product is divided into two parts of equal composition, one of which as a circulating gas recycle to the reaction zone.

2. The method according to claim 1, wherein forming at least one fixed catalyst bed of dehydrogenation, which contains from 10 to 99.9 wt.% zirconium dioxide, from 0 to 60 wt.% 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, one element of the third subgroup, one element of the eighth subgroup of the Periodic system of the elements, lanthanum and/or tin, provided that the sum of the weight percent amounts to 100 wt.%.

3. The method according to claim 1 or 2, characterized in that a stationary catalyst bed includes the wiring and/or rings of the catalyst.

4. The method according to claim 1 or 2, characterized in that subject dehydrogenating the hydrocarbon is propane and/or butane.

5. The method according to claim 1 or 2, characterized in that the reaction gas exclusively before his entrance into the reaction zone, introducing at least one ha is, containing molecular oxygen.

6. The method according to claim 1 or 2, characterized in that at least one gas containing molecular oxygen, serves the air.

7. The method according to claim 1 or 2, characterized in that in the reaction zone in addition to the circulating gas is not available other gas containing molecular hydrogen.

8. The method according to claim 1 or 2, characterized in that fed into the reaction zone of the reaction gas contains water vapor.

9. The method according to claim 1 or 2, characterized in that the recirculated to the reaction zone as part of the circulating gas withdrawn from the reaction zone of the gas product is from 20 to 80% of the total output of the gas product.

10. The method according to claim 1 or 2, characterized in that a portion of the gaseous product from the reaction zone, not recycled into the reaction zone as a circulating gas, if necessary, after partial separation therein that is different from at least one subject to dehydrogenation of the hydrocarbon components are used with the purpose of partial oxidation and/or amoxiline negidrirovannogo carbon.

11. The method according to claim 1 or 2, characterized in that the reaction gas contains as an additive a second circulating gas obtained by partial oxidation and/or amoxiline negidrirovannogo hydrocarbon containing at least one subject dehydrogenating hydrocarbons.

12. The method according to claim 1 or 2, characterized in that the second circulating gas obtained by partial oxidation and/or amoxiline negidrirovannogo hydrocarbons recycled to the reaction zone, is the only oxygen-containing gas supplied into the reaction zone.

13. The method of claim 1 or 2, characterized in that it is carried out in a reactor with circulation of the reaction mixture containing the jet pump.



 

Same patents:

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1 dwg

FIELD: petrochemical processes.

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FIELD: petrochemical processes.

SUBSTANCE: branched olefins are obtained via dehydrogenation of isoparaffin composition containing 0.5% or less quaternary aliphatic carbon atoms in presence of suitable catalyst. Isoparaffin composition is prepared via hydrocracking and hydroisomerization of paraffin wax and contains paraffins with 7 to 18 carbon atoms, these paraffins or at least a part of them are branched with average number of branches between 0.5 and 2.5 per paraffin molecule, the branches including methyl and optionally ethyl ones. Original paraffin wax is prepared using Fischer-Tropsch reaction. Resulting branched olefins are characterized by content of quaternary aliphatic structures 0.5% or less. Branched aromatic hydrocarbon and compositions of branched olefins, branched aromatic hydrocarbon, and branched alkylarenesulfonates are also disclosed.

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10 cl, 19 ex

FIELD: petrochemical processes.

SUBSTANCE: branched olefins are obtained via catalytic dehydration of isoparaffin composition including 0.5% or less of quaternary aliphatic carbon atoms. This isoparaffin composition comprises paraffins with number of carbons within a range of 7 to 35, said paraffins or at least a part thereof being branched with average number of branches from 0.7 to 2.5 and said branches including methyl and optionally ethyl branches. Indicated isoparaffin composition with is obtained via hydrocracking and hydroisomerization of wax. Thus obtained branched olefins contain 0.5% or less of quaternary aliphatic carbon atoms.

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8 cl, 4 tbl, 11 ex

FIELD: industrial organic synthesis.

SUBSTANCE: ethylbenzene blend obtained through blending fresh ethylbenzene and recycled ethylbenzene with styrene content not above 0.1 wt % is subjected to catalytic dehydrogenation in presence of water steam at feed-to-steam weight ratio 1:2, temperature 600°C, ethylbenzene blend supply space velocity 0.5-1.0 h-1, and reactor pressure maintained within a range of 45 to 80 kPa absolute. Multistep rectification gives rectified styrene with concentration of desired product at least 99.8% and phenylacetylene impurity level not higher than 0.01 wt %. Recycled ethylbenzene is blended with fresh ethylbenzene and resulting ethylbenzene blend containing no more than 0.1 wt % styrene is supplied to dehydrogenation unit.

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5 tbl

FIELD: petrochemical industry; methods of production of styrene.

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EFFECT: the invention ensures the increased purity of the produced styrene without reduction of productivity of the whole process of the marketable styrene.

1 tbl, 8 ex

FIELD: organic chemistry, chemical technology, catalysts.

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EFFECT: improved and valuable properties of catalyst.

12 cl, 2 tbl

FIELD: hydrogenation-dehydrogenation catalysts.

SUBSTANCE: invention provides catalytic composition for dehydration of alkylaromatic hydrocarbons optionally combined with ethane comprising: carrier consisting of alumina in δ phase or in θ phase, or in mixed δ+θ or θ+α, or δ+θ+α phase, modified with silicon oxide and having surface area less than 150 m2/g as measured by BET method; 0.1-35% gallium in the form of Ca2O3; 0.01-5% manganese in the form of Mn2O3; 0-100 ppm platinum; and 0.05-4% alkali or alkali-earth metal oxide, all percentages being based on the total weight of composition. Other variants of composition are also covered by invention. Methods of preparing such catalytic composition (options) envisage use of alumina-based carrier in the form of particles corresponding to group A of the Geldart Classification. Process of dehydration of alkylaromatic hydrocarbons optionally combined with ethane comprises: (i) dehydration of hydrocarbon stream optionally mixed with inert gas in fluidized-bed reactor in presence of catalytic composition consisted of alumina-supported and silica-modified gallium and manganese at temperature within a range of 400 to 700°C, total pressure within a range of 0.1 to 3 atmospheres, and gas hourly space velocity from 50 to 10000 h-1; and (ii) regeneration and heating of catalyst caused by catalytic oxidation of fuel in fluidized-bed reactor at temperature above 400°C.

EFFECT: increased activity of catalytic composition and prolonged lifetime thereof.

22 cl, 2 tbl, 16 ex

FIELD: petroleum chemistry, organic chemistry, chemical technology.

SUBSTANCE: method involves contacting the parent raw flow in the flow-type reactor with oxygen-free gas flow at increased temperature with a catalyst comprising a precious metal of VII group of the periodic system of elements. The industrial isomerization platinum-containing catalyst SI-1 or industrial hydrogenation catalyst "palladium on active aluminum oxide in sulfured form" is used as a catalyst. Contact of the parent raw with catalyst is carried out by its feeding in inert gas flow, for example, nitrogen at the volume rate 1-2 h-1 at temperature 320-370°C in the presence of the additive representing a solution of hydroquinone or p-benzoquinone in isopropyl alcohol and taken in the concentration 0.01-0.5 mole/l wherein the additive is fed to the parent raw flow in the amount 5-30 vol.%. Invention provides carrying out the highly selective isomerization and cyclization of light petroleum fractions in on industrial Pt- and/or Pd-containing catalysts with the high yield of the end products no containing aromatic compounds and not requiring the presence of hydrogen or hydrogen-containing gas for its realization and regeneration of the catalyst.

EFFECT: improved method for isomerization.

4 cl, 2 tbl, 2 ex

FIELD: chemistry of aromatic compounds, chemical technology.

SUBSTANCE: process involves the following stages: feeding (C2-C5)-alkane, for example, ethane and (C2-C5)-alkyl-substituted aromatic compound, for example, ethylbenzene into dehydrogenation reactor for the simultaneous dehydrogenation to (C2-C5)-alkene, for example, to ethylene, and (C2-C5)-alkenyl-substituted aromatic compound, for example, styrene; separation of the outlet dehydrogenation flow for extraction of gaseous flow containing alkene, hydrogen and alkane, and for extraction of aromatic compounds with the high effectiveness by cooling and compression; feeding a gaseous flow and (C6-C12)-aromatic compound into the alkylation reactor for preparing the corresponding (C2-C5)-alkyl-substituted aromatic compound that is recirculated into the dehydrogenation reactor; feeding the blowing flow from the alkylation unit containing alkane and hydrogen for the separation stage by using cryogenic separator for extraction of alkane that is recirculated into the dehydrogenation reactor, and hydrogen that is extracted with the purity value 99%. Invention provides the development of economic and highly effective process for preparing alkenyl-substituted aromatic compounds.

EFFECT: improved preparing method.

61 cl, 2 tbl, 2 dwg, 2 ex

FIELD: hydrogenation-dehydrogenation catalysts.

SUBSTANCE: invention relates to production of olefin or diolefin hydrocarbons via dehydrogenation of corresponding paraffinic C3-C5-hydrocarbons carried out in presence of catalyst comprising chromium oxide and alkali metal deposited on composite material including alumina and aluminum wherein percentage of pores larger than 0.1 μm is 10.0-88.5% based on the total volume of open pores equal to 0.10-0.88 cm3/g. Preparation of catalyst involves treatment of carrier with chromium compound solution and solution of modifying metal, preferably sodium or sodium and cerium. Carrier is prepared by from product resulting from thermochemical activation of amorphous hydrargillite depicted by formula Al2O3·nH2O, where 0.25<n<2.0, added to homogenous mass in amount 1.0 to 99.0% using, as additional material, powdered aluminum metal, which is partly oxidized in hydrothermal treatment and calcination stages. Hydrocarbon dehydrogenation process in presence of the above-defined catalyst is also described.

EFFECT: increased activity and selectivity of catalyst.

3 cl, 2 dwg, 4 tbl, 7 ex

FIELD: petrochemical processes.

SUBSTANCE: simultaneous dehydrogenation of mixture containing alkyl and alkylaromatic hydrocarbons is followed by separating thus obtained dehydrogenated alkyl hydrocarbon and recycling it to alkylation unit. Dehydrogenation reactor-regenerator employs C2-C5-alkyl hydrocarbon as catalyst-transportation carrying medium.

EFFECT: increased process flexibility and extended choice of catalysts.

36 cl

FIELD: petrochemical processes.

SUBSTANCE: 1,3-butadiene is obtained via catalytic dehydrogenation of n-butylenes at 580-640°C and essentially atmospheric pressure while diluting butylenes with water steam at molar ratio 1:(10-12) and supplying butylenes at space velocity 500-750 h-1. Catalyst is composed of, wt %: K2O 10-20, rare-earth elements (on conversion to CeO2) 2-6, CaO and/or MgO 5-10. MoO3 0.5-5, Co2O3 0.01-0.1, V2O5 0.01-0.1, and F2O3 the balance. Once steady condition is attained, dehydrogenation is carried out continuously during all service period of catalyst.

EFFECT: increased yield of 1,3-butadiene and process efficiency.

2 ex

FIELD: hydrogenation-dehydrogenation catalysts.

SUBSTANCE: invention concerns catalysts for dehydrogenation of C2-C5-alkanes into corresponding olefin hydrocarbons. Alumina-supported catalyst of invention contains 10-20% chromium oxide, 1-2% alkali metal compound, 0.5-2% zirconium oxide, and 0.03-2% promoter oxide selected from zinc, copper, and iron. Precursor of alumina support is aluminum oxide hydrate of formula Al2O3·nH2O, where n varies from 0.3 to 1.5.

EFFECT: increased mechanical strength and stability in paraffin dehydrogenation process.

9 cl, 1 dwg, 3 tbl, 7 ex

FIELD: petroleum chemistry, chemical technology.

SUBSTANCE: invention relates to dehydrogenation of isoamylenes to isoprene on iron oxide self-regenerating catalysts. Method involves addition of piperylenes in the concentration up to 4 wt.-% representing a by-side product in manufacturing process of isoprene by the indicated method to the parent isoamylenes before their dehydrogenation. Method provides enhancing selectivity of method for isoamylenes dehydrogenation to isoprene in the presence of iron oxide self-regenerating catalysts.

EFFECT: improved preparing method.

1 tbl, 6 ex

FIELD: chemistry of aromatic compounds, chemical technology.

SUBSTANCE: process involves the following stages: feeding (C2-C5)-alkane, for example, ethane and (C2-C5)-alkyl-substituted aromatic compound, for example, ethylbenzene into dehydrogenation reactor for the simultaneous dehydrogenation to (C2-C5)-alkene, for example, to ethylene, and (C2-C5)-alkenyl-substituted aromatic compound, for example, styrene; separation of the outlet dehydrogenation flow for extraction of gaseous flow containing alkene, hydrogen and alkane, and for extraction of aromatic compounds with the high effectiveness by cooling and compression; feeding a gaseous flow and (C6-C12)-aromatic compound into the alkylation reactor for preparing the corresponding (C2-C5)-alkyl-substituted aromatic compound that is recirculated into the dehydrogenation reactor; feeding the blowing flow from the alkylation unit containing alkane and hydrogen for the separation stage by using cryogenic separator for extraction of alkane that is recirculated into the dehydrogenation reactor, and hydrogen that is extracted with the purity value 99%. Invention provides the development of economic and highly effective process for preparing alkenyl-substituted aromatic compounds.

EFFECT: improved preparing method.

61 cl, 2 tbl, 2 dwg, 2 ex

FIELD: petroleum chemistry, organic chemistry, chemical technology.

SUBSTANCE: method involves contacting the parent raw flow in the flow-type reactor with oxygen-free gas flow at increased temperature with a catalyst comprising a precious metal of VII group of the periodic system of elements. The industrial isomerization platinum-containing catalyst SI-1 or industrial hydrogenation catalyst "palladium on active aluminum oxide in sulfured form" is used as a catalyst. Contact of the parent raw with catalyst is carried out by its feeding in inert gas flow, for example, nitrogen at the volume rate 1-2 h-1 at temperature 320-370°C in the presence of the additive representing a solution of hydroquinone or p-benzoquinone in isopropyl alcohol and taken in the concentration 0.01-0.5 mole/l wherein the additive is fed to the parent raw flow in the amount 5-30 vol.%. Invention provides carrying out the highly selective isomerization and cyclization of light petroleum fractions in on industrial Pt- and/or Pd-containing catalysts with the high yield of the end products no containing aromatic compounds and not requiring the presence of hydrogen or hydrogen-containing gas for its realization and regeneration of the catalyst.

EFFECT: improved method for isomerization.

4 cl, 2 tbl, 2 ex

FIELD: hydrogenation-dehydrogenation catalysts.

SUBSTANCE: invention provides catalytic composition for dehydration of alkylaromatic hydrocarbons optionally combined with ethane comprising: carrier consisting of alumina in δ phase or in θ phase, or in mixed δ+θ or θ+α, or δ+θ+α phase, modified with silicon oxide and having surface area less than 150 m2/g as measured by BET method; 0.1-35% gallium in the form of Ca2O3; 0.01-5% manganese in the form of Mn2O3; 0-100 ppm platinum; and 0.05-4% alkali or alkali-earth metal oxide, all percentages being based on the total weight of composition. Other variants of composition are also covered by invention. Methods of preparing such catalytic composition (options) envisage use of alumina-based carrier in the form of particles corresponding to group A of the Geldart Classification. Process of dehydration of alkylaromatic hydrocarbons optionally combined with ethane comprises: (i) dehydration of hydrocarbon stream optionally mixed with inert gas in fluidized-bed reactor in presence of catalytic composition consisted of alumina-supported and silica-modified gallium and manganese at temperature within a range of 400 to 700°C, total pressure within a range of 0.1 to 3 atmospheres, and gas hourly space velocity from 50 to 10000 h-1; and (ii) regeneration and heating of catalyst caused by catalytic oxidation of fuel in fluidized-bed reactor at temperature above 400°C.

EFFECT: increased activity of catalytic composition and prolonged lifetime thereof.

22 cl, 2 tbl, 16 ex

FIELD: organic chemistry, chemical technology, catalysts.

SUBSTANCE: invention describes a catalyst for dehydrogenation of (C2-C5)-hydrocarbons that comprises aluminum, chrome oxides, compound of modifying metal, alkaline and/or alkaline-earth metal. Catalyst comprises additionally silicon and/or boron compounds and as a modifying agent the proposed catalyst comprises at least one compound chosen from the following group: zirconium, titanium, iron, gallium, cobalt, molybdenum, manganese, tin. The catalyst is formed in the process of thermal treatment of aluminum compound of the formula Al2O3. n H2O wherein n = 0.3-1.5 and in common with compounds of abovementioned elements and shows the following composition, wt.-% (as measure for oxide): chrome oxide as measured for Cr2O3, 12-23; compound of a modifying metal from the group: Zr, Ti, Ga, Co, Sn, Mo and Mn, 0.1-1.5; silicon and/or boron compound, 0.1-10.0; alkaline and/or alkaline-earth metal compound, 0.5-3.5, and aluminum oxide, the balance. Catalyst shows the specific surface value 50-150 m2/g, the pore volume value 0.15-0.4 cm3/g and particles size 40-200 mcm. Also, invention describes a method for preparing this catalyst. Invention provides preparing the catalyst showing the enhanced strength and catalytic activity.

EFFECT: improved and valuable properties of catalyst.

12 cl, 2 tbl

FIELD: petrochemical industry; methods of production of styrene.

SUBSTANCE: the invention is pertaining to the field of petrochemical industry, in particular, to the method of production of styrene. The invention provides for dehydrogenation of the ethylbenzene charge gained after mixing of the fresh ethylbenzene with the recycled ethylbenzene on the ferrioxide catalytic agent at presence of the steam at the mass ratio of the raw to the steam of no less than 1:2, at the temperature of 580-640°С and the volumetric speed of feeding of the ethylbenzene charge of 0.23-0.45 m3/h. The hydrocarbon condensate (the product of the dehydrogenation) containing styrene, the unreacted ethylbenzene, the by-products including the phenyl acetylene impurity before the stage of the rectification is hydrogenated using the palladium-containing catalytic agents at the temperature of 20-30°С, the volumetric speed of 4.5-5.0 m3/h-1 and at the volumetric ratio of the hydrogen : raw - 35-45. The technical result of the invention is the increased purity of the produced styrene without reduction of productivity of the whole process of the marketable styrene.

EFFECT: the invention ensures the increased purity of the produced styrene without reduction of productivity of the whole process of the marketable styrene.

1 tbl, 8 ex

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