Method of producing maleic anhydride and catalyst used therein (versions)

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing maleic anhydride in a fluidised bed by oxidising material which contains C4 hydrocarbons with molecular oxygen or oxygen-containing gas in a reactor with a fluidised bed at reactor temperature 325-500°C in the presence of a catalyst capable of working in the fluidised bed, containing mixed oxides of vanadium and phosphorus, wherein the catalyst is prepared as follows: (a) preparation of a catalyst precursor containing mixed vanadium and phosphorus oxide; (b) packing the catalyst precursor; (c) crushing the catalyst precursor to particles whose average size is less than one micrometre in diametre; (d) moulding particles which are capable of working in the fluidised bed, with bulk density greater than or equal to 0.75 g/cm3 from the packed crushed catalyst precursor; and (e) annealing said particles in boiling conditions, where output of the maleic anhydride is increased by adding a compensating catalyst into the reactor with the fluidised bed, wherein said compensating catalyst contains alkyl ether of orthophosphoric acid of formula (RO)3P=O, where R is hydrogen or C1-C4 alkyl and at least one R is C1-C4 alkyl, where the compensating catalyst is prepared by saturating the catalyst obtained according to steps (a) to (e) with alkyl ether of orthophosphoric aid. The invention also discloses a method of improving operation of the mixed vanadium-phosphorus oxide catalyst for producing maleic anhydride from butane in a fluidised bed. The invention also relates to a catalyst capable of working in the fluidised bed, for producing maleic acid by oxidising material which contains C4 hydrocarbons.

EFFECT: invention ensures high output of the end product at low working temperatures.

31 cl, 2 tbl, 2 ex

 

The technical field

The present invention relates to a method for producing a fluidized bed of maleic acid or maleic anhydride from chetyrehrjadnyh hydrocarbons in the presence of a vanadium-phosphorus oxide catalyst (VPO), and loss of phosphorus from the catalyst during operation are compensated by impregnation of a VPO catalyst alkilany ether orthophosphoric acid, such as triethyl phosphate (TER), and addition of the catalyst is impregnated alkilany ether, boiling layer of catalyst that increases the activity of the catalyst.

The level of technology

Annually in the world get maleic anhydride in large amounts as maleic anhydride can be used as a multifunctional intermediate compounds in chemical synthesis and is often used in the production of alkyl resins. Maleic acid is a precursor of maleic anhydride and can also be used as the starting material for obtaining 1,4-butanediol (DO).

Maleic anhydride can be obtained vapor-phase oxidation of n-butane in air in the presence of a vanadium-phosphorus-oxide (VPO) catalyst in a fixed bed or fluidized bed.

Advantages ways oxidation of hydrocarbons in a fluidized layer in comparison with the methods of oxidation of hydrocarbons in a fixed bed well-known specialist who, because include the possibility of temperature control and heat transfer during the oxidation reaction.

Still the catalysts containing the oxides of vanadium and phosphorus, were used to produce maleic anhydride by oxidation chetyrehrjadnyh hydrocarbons such as n-butane, n-butenes, 1,3-butadiene or mixtures thereof with molecular oxygen or oxygen-containing gas. Traditional methods of preparing such catalysts include the reduction of compound of pentavalent vanadium and combining it with the compound of phosphorus and optionally compounds promoters in the conditions under which the valency of vanadium is less than +5, with the formation of the catalyst precursor, capable of being converted into oxide of vanadium-phosphorus. Then oxide catalyst precursor is isolated and converted into an active catalyst before or after the formation of the desired catalyst particles or for stationary layer or fluidized bed.

In U.S. patent 3888886, 3905914, 3931046, 3932305 and 3975300 disclosed checked vanadium-phosphorus oxide catalysts for the synthesis of maleic anhydride from butane in the reactor with a diameter of one inch fluidized bed. In most examples, the catalysts were prepared by forming a catalyst precursor in aqueous media (patent 2975300 predecessor received in the form of paste, vanadium compounds, link the phosphorus and organic reductant), drying and then grinding and sifting predecessor with the formation of a powder with a particle size of about 74-250 microns. However, this method does not allow to obtain abrasion-resistant catalyst particles, which is necessary for successful work in a fluidized bed.

Industrial catalysts for fluidized bed mainly represent microspheroidal particles with an average diameter of about 20-300 microns, preferably containing about 80% of particles with diameter in the range of about 30-80 microns. Most preferably, about 25-40% of the particles had an average diameter less than 45 microns.

In U.S. patent 4647673 disclosed a method of preparation of abrasion resistant microspheroidal catalysts for fluidized bed containing mixed oxides of vanadium and phosphorus, in which the precursor of vanadium-phosphorus mixed oxide catalyst compacted, crushed, formed into particles to the fluidized bed and calcined at conditions close to the conditions of the fluidized bed.

As in the case of other vanadium phosphate catalysts used for the oxidation of butane in a fluidized or fixed bed, the catalyst is lost phosphorus. These losses can lead to reduced yield of maleic anhydride. This loss has a negative impact on the performance and Economics of production. So have developed the means of introducing phosphorus to compensate for the losses of phosphorus and consequently, partial or full replacement of reduced output. Continuous addition of phosphorus also gives the advantage that the yield of maleic anhydride is maintained at economical and stable.

In the description of the British patent 1464198 disclosed reactivation or regeneration of some vanadium-phosphorus-oxygen catalyst complexes promoted zirconium, hafnium, chromium, iron, lanthanum or cerium, by contact during vapor-phase oxidation with alkilany ether orthophosphoric acid of the formula (RO)3P=O, where R is hydrogen or alkyl (C1-C4and at least one R is alkyl (C1-C4.

In U.S. patent 4701433, Edwards and others, disclosed a method for the production of maleic anhydride from butane in the presence of a vanadium-phosphorus-oxygen catalyst or a vanadium-phosphorus-oxygen catalyst containing additional metal; when using this catalyst in the reaction system, water is added and the compound of phosphorus for reversible deactivation of part of the catalyst layer, in which there is local overheating, before adding phosphorus compounds, and the addition of phosphorus compounds shifts the area of local overheating in the downstream catalyst bed, which allows you to get an improved catalyst bed due to partial reagent is catalyst AI in the original area of local overheating and provides more izotermicznym the catalyst bed.

Although Edwards and others have proposed to use to improve yield more izotermicznym the catalyst bed, They had reached the desired temperature more isotherming catalyst layer by shifting the initial zone of local overheating in the new location and then reactivate the old zones. Edwards showed that the yield can be improved, because there is a sufficient layer of catalyst, whereby the area of local overheating can move. Edwards did not consider that the constant movement of the zone of local overheating is inherently unstable and not suitable for continuous operation.

In U.S. patent 4780548, Edwards and others, proposed a continuous vapor-phase oxidation of n-butane to maleic anhydride, in which n-butane and molecular oxygen or air is brought into contact with an hourly volume rate of about 100-4000 cm3materials on cm3of catalyst per hour with a vanadium-phosphorus-oxygen catalyst; the catalyst regenerate continuously or intermittently in contact during vapor-phase oxidation with alkilany ether orthophosphoric acid of the formula (RO)3P=O, where R is hydrogen or alkyl (C1-C4and at least one R is alkyl (C1-C4and in the gas flow of the raw materials fed to the reactor, add about 1000-40000 parts per million by weight of water. The gas flow is Aria in the reactor will contain about 0.2-1.7 mol.% n-butane, and for optimal output in the proposed method is the content of n-butane of about 0.8-1.5 mol.%. Edwards showed that it is possible to use higher concentrations, but it is necessary to consider the possibility of an explosion. Although Edwards has shown that it is possible to apply an explosive mixture with the content of n-butane above 1.5-1.7 mol, Edwards did not understand what isothermal reaction at higher concentrations of n-butane can provide a high output for a long time, despite the danger of an explosion.

Becker and others, U.S. patent 4795818, opened the way to optimize output on vanadium-phosphorus catalyst during the oxidation of n-butane to maleic anhydride, which is constantly added volatile compound of phosphorus with the speed required to maintain maximum output at a constant working temperature and the working temperature is preferably monitored at the gas outlet. Becker and others have shown that the amount of added phosphorus compounds should be sufficient in order to avoid reduction of the working temperature. Becker and others did not suggest the introduction of water into the reaction, and studied only the addition of volatile phosphorus compounds.

In U.S. patent 4515899, Click, etc. shown that the service life of the vanadium-phosphorus-oxygen catalyst in the reactor with a porous layer can be increased by treating a compound of phosphorus with PEFC is blowing the steam processing and use of data on the movement area of local overheating on the layer of catalyst.

In U.S. patent 5117007 revealed a continuous way to obtain maleic anhydride by the partial oxidation of a hydrocarbon feedstock containing n-butane at a concentration of at least 1.8 mole%, in which the mixture of feedstock and oxidant is brought into contact with a vanadium-phosphorus-oxygen catalyst, and an aqueous solution Olkiluoto ether phosphoric acid is continuously added to the raw material, and the ratio of water and elemental phosphorus in the specified Akilova ether is in the range from about 6500:1 by weight up to 50,000:1 by weight (water to phosphorus) and the temperature difference between the reaction throughout the reaction zone is less than about 45°C (80°F).

The reaction of partial oxidation of n-butane to maleic anhydride is highly exothermic and the temperature zone of local overheating of the catalyst can be increased, if possible, the yield of the reaction under control, and then completely stop product education. This rise in the temperature zone of local overheating in the reactor with a fixed bed can very adversely affect the oxidation reaction. High-temperature area local overheating can easily occur during oxidation, and it is very sensitive to changes in the concentration of hydrocarbons in the feedstock. A small increase in the concentration of hydrocarbons in the raw materials can lead to large changes in temperature zone IU the private overheating and reduce the selectivity and yield. In addition, the high temperature zone local overheating can shorten the life of the used catalyst. Therefore, to obtain high output and long service life it is necessary to avoid excessively high temperature in the area of local overheating and to maintain the catalyst in the isothermal mode, the entire length of the reaction zone. Also for consistently high product yield, you must have a stable process parameters.

In U.S. patent 5117007 revealed that the positive effect of adding an aqueous solution of phosphorus compounds in a concentration range for the regulation of the temperature profile of the reaction of oxidation of n-butane to maleic anhydride can be obtained throughout the reaction zone of the reactor with fixed bed. A positive effect is achieved throughout the reaction zone, including the area of local overheating, but the positive effect is also achieved for the temperature profile of the reaction, despite working in the area of ignition, which is determined by the concentration of n-butane feedstock from about 1.7 mol.% or higher, when using air as the oxygen source. The desired ratio of water to phosphorus compound of phosphorus depends on the concentration of n-butane, as well as the size and shape of the reactor. Thus the isothermal mode in zones of the reaction, moreover, the temperature gradient in the reaction zone is at a maximum interval of approximately 45°C (80°F), which is accompanied by an increase in the total output.

As shown above, one way in technology, the introduction of phosphorus based on the addition of phosphorus in the vapor phase to the catalyst in a fixed bed or fluidized bed. Another way of introducing phosphorus phosphorus type, such as triethyl phosphate (TER) in the vapor phase. This technology has a positive effect on the stabilization of output and prevents the loss of the catalyst; however, the undesirable effect of adding phosphorus to the VPO-catalyst in a fluidized bed used for the oxidation of butane to maleic acid or maleic anhydride, is to increase the operating temperature. Increased temperature causes undesirable consequences, such as limiting the performance of the reactor and an accelerated decline of physical properties of the catalyst, in particular values of the surface and pore volume, which are important for good performance of the catalyst. It is therefore necessary to find a way of introducing phosphorus in the oxidation reaction of butane, which can increase the yield of maleic anhydride without increasing the operating temperature, which affects the state of the catalyst.

The authors found that the impregnation VPO-catalyst alkilany ether orthophosphate type Tr is ethylphosphate (TER) the TER-soaked VPO catalyst can be used for introduction of phosphorus in the reaction of oxidation of butane in the fluidized bed, which leads to the desired increase in the yield of maleic anhydride at a lower operating temperature and in addition significantly lower concentration TER compared with the method of introduction TER in the vapor phase.

Thus, the present invention has the advantages that allows you to add phosphorus, not vasavya temperature increase, which would harm the catalyst, and enables you to use fewer TER to compensate for losses of phosphorus, which provides economic benefits.

The invention

The present invention relates to a method for producing a fluidized bed of maleic anhydride by the oxidation of a feedstock containing hydrocarbons With4molecular oxygen or oxygen-containing gas in a fluidized bed reactor at a reactor temperature of about 325-500°C in the presence of abrasion-resistant, able to work in a fluidized mode microspheroidal catalyst containing mixed oxides of vanadium and phosphorus, in which the catalyst is prepared in the following way:

(a) preparation of catalyst precursor containing mixed oxides of vanadium and phosphorus;

(b) sealing catalyst precursor;

(c) crushing of the catalyst precursor to the average particle size diameter of less than about one micron;

(d) forming particles, capable of R is to work in the boiling mode, with a bulk density of more than or equal to 0.75 g/cm3of compacted crushed catalyst precursor; and

(e) annealing under boiling particles suitable for use in a fluidized mode in which the catalyst activity increases when added to the catalyst Olkiluoto ether orthophosphoric acid of the formula (RO)3P=O, where R is hydrogen or alkyl (C1-C4and at least one R is alkyl (C1-C4in a quantity sufficient to achieve a concentration of approximately 0.000002-1.0 pounds Olkiluoto ester of orthophosphoric acid per 100 pounds of total catalyst per day.

The present invention also relates to a method for producing maleic anhydride in a fluidized bed oxidation of a raw material containing a hydrocarbon, C4molecular oxygen or oxygen-containing gas in a fluidized bed reactor at a reactor temperature of about 325-500°C in the presence of abrasion-resistant, suitable for use in a fluidized mode microspheroidal catalyst containing mixed oxides of vanadium and phosphorus, in which the catalyst is prepared in the following way:

(a) preparation of catalyst precursor containing a mixed oxide of vanadium and phosphorus;

(b) sealing catalyst precursor;

(c) crushing of the catalyst precursor is about average particle size diameter of less than about one micron;

(d) forming particles, able to work in a fluidized mode, with a bulk density greater than or equal to 0.75 g/cm3of compacted crushed catalyst precursor; and

(e) annealing under boiling particles suitable for use in a fluidized mode in which the catalyst activity increases with the addition of a catalyst containing about 1-25 parts by weight Olkiluoto ether orthophosphoric acid of the formula (RO)3P=O, where R is hydrogen or alkyl (C1-C4and at least one R is alkyl (C1-C4on 100 parts by weight of the catalyst.

Preferred alkylamino esters of phosphoric acid are triethyl phosphate and trimethylphosphate.

In the present invention VPO catalyst for fluidized bed mixed with alkilany ether orthophosphoric acid, such as triethyl phosphate, alkilany ether phosphoric acid absorbed in the pores of the catalyst and the catalyst becomes saturated alkilany ether orthophosphoric acid. When soaked TER catalyst is introduced into the fluidized bed reactor, alkilany ether orthophosphoric acid stands out and is a source of phosphorus to improve the activity of the catalyst. The catalyst impregnated alkilany ether phosphoric acid, can be introduced into the reactor one or it can be mixed with cat what lyst which was not impregnated alkilany ether phosphoric acid, with the education suitable for work in a fluidized mode mixture, providing essential for catalysis of a reaction amount Olkiluoto ether orthophosphoric acid.

The present invention also relates to abrasion resistant and capable of boiling microspheroidal catalyst containing mixed oxides of vanadium and phosphorus, the catalyst is prepared as follows:

(a) preparation of catalyst precursor containing a mixed oxide of vanadium and phosphorus;

(b) sealing catalyst precursor;

(c) crushing of the catalyst precursor to the average particle size diameter of less than about one micron;

(d) forming particles, able to work in a fluidized bed, with a bulk density of more than or equal to 0.75 g/cm3of compacted crushed catalyst precursor; and

(e) annealing under boiling particles, able to work in a fluidized mode, and

(f) a mixture suitable for use in fluidized-bed catalyst, obtained in stage (e), with alkilany ether orthophosphoric acid of the formula (RO)3P=O, where R is hydrogen or alkyl (C1-C4and at least one R is alkyl (C1-C4from education to work in the boiling mode, the cat who lyst containing about 1-25 parts by weight Olkiluoto ester of orthophosphoric acid per 100 parts by weight of catalyst, preferably about 7-23 parts by weight Olkiluoto ester of orthophosphoric acid per 100 parts by weight of the catalyst, more preferably about 8-21 parts by weight Olkiluoto ester of orthophosphoric acid per 100 parts by weight of the catalyst and more preferably about 16 to 19 parts by weight Olkiluoto ester of orthophosphoric acid per 100 parts by weight of the catalyst.

Preferred alkylamino esters of phosphoric acid are triethyl phosphate and trimethylphosphate.

Further, the present invention relates to abrasion-resistant, suitable for use in a fluidized mode microspheroidal catalyst containing mixed oxides of vanadium and phosphorus, the catalyst is prepared as follows:

(a) preparation of catalyst precursor containing a mixed oxide of vanadium and phosphorus;

(b) sealing catalyst precursor;

(c) crushing of the catalyst precursor to particles of average size less than about one micron in diameter;

(d) forming particles, able to work in a fluidized bed, with a bulk density greater than or equal to 0.75 g/cm3of compacted crushed catalyst precursor; and

(e) annealing in which the conditions of evaporating particles, able to work in a fluidized mode, and

(f) a mixture suitable for use in fluidized-bed catalyst, obtained in stage (e), triethyl phosphate with the formation able to work in a fluidized mode catalyst containing about 1-25 parts by weight of triethyl phosphate to 100 parts by weight of catalyst, preferably about 7-23 parts by weight of triethyl phosphate to 100 parts by weight of the catalyst; more preferably about 8-21 parts by weight of triethyl phosphate to 100 parts by weight of the catalyst and more preferably about 16 to 19 parts by weight of triethyl phosphate to 100 parts by weight of the catalyst.

Description of the preferred options

The present invention relates to a method for producing a fluidized bed of maleic acid or maleic anhydride from raw materials containing hydrocarbons with 4 carbon atoms, in the presence of a vanadium-phosphorus-oxide (VPO) catalyst, in which the phosphorus lost by the catalyst during the reaction, filled impregnation VPO-catalyst alkilany ether orthophosphoric acid of the formula (RO)3P=O, where R is hydrogen or alkyl (C1-C4and at least one R is alkyl (C1-C4such as triethyl phosphate (TER), and the introduction of impregnated TER catalyst in a fluidized bed of catalyst. This improves the catalyst and leads to the isenau output of maleic anhydride at lower operating temperatures.

The old ways of introducing phosphorus included a method of simultaneous introduction of triethyl phosphate (TER) in the vapor phase;

however, undesirable way increased operating temperature. In the result it is obvious that you need an alternative way of introducing phosphorus, which would lead to the same increase in output as the introduction TER, but without increasing operating temperature.

The authors found that the prepared catalyst enriched alkilany ether orthophosphoric acid, such as TER, can be used for the introduction of the necessary phosphorus and increase output without accompanying undesirable growth of operating temperature.

Maleic anhydride receive a vapor-phase oxidation of n-butane in air using a vanadium-phosphorus-oxygen catalyst (VPO) in a fluidized bed. As in the case of other vanadium phosphate catalysts for the oxidation of butane in a fluidized bed or a fixed bed, during operation of the catalyst is lost phosphorus. This loss can lead to reduction of the yield of maleic anhydride. This loss has a negative impact on plant performance and Economics of production. So have developed ways of introducing phosphorus to compensate for the loss of phosphorus and, therefore, reduction of part or all of the output. Continuous addition of phosphorus also gives the advantage that the output m is leinbaugh anhydride is stored on economical and stable.

To compensate for the loss of phosphorus was previously applied technology introduction of phosphorus, based on the introduction into the catalyst in a fixed or fluidized bed of triethyl phosphate (TER) in the vapor phase. This technology was very effective in achieving the desired effect of stabilizing and preventing the reduction of the yield of maleic anhydride in the way fluidized bed; however, an undesirable consequence of the introduction of phosphorus into the fluidized bed VPO-catalyst is increased operating temperatures. High temperature causes negative effects, for example, limits the performance of the reactor and leads to accelerated deterioration of the physical properties of the catalyst, including the values of the surface and pore volume, which are important for good performance of the catalyst.

The authors found that by impregnation VPO-catalyst alkilany ether phosphoric acid type triethyl phosphate and periodic add propiano catalyst in fluidized bed VPO-catalyst can enter phosphorus in VPO-way catalyst in a fluidized bed to increase the yield of maleic anhydride at a lower operating temperature. An additional advantage is the fact that it takes significantly fewer Olkiluoto ether phosphoric acid than the introduction of Olkiluoto ester of orthophosphoric acid in the vapor phase is in the previous practice. When mixed VPO-catalyst with alkilany ether orthophosphoric acid, such as TER, liquid TER is absorbed in the pores of the catalyst. Adding a catalyst to the fluidized bed reactor through a supply tube catalyst TER evaporates and is involved in the way that leads to increased activity of the catalyst as a result of replacement of phosphorus and higher outputs of maleic anhydride at lower temperatures.

The preferred alkylphosphate is alkilany ether orthophosphoric acid of the formula (RO)3P=O, where R is hydrogen or alkyl (C1-C4and at least one R is alkyl (C1-C4. The preferred phosphorus compounds are triethyl phosphate (TER) or trimethylphosphate.

For example, VPO catalyst impregnated with triethyl phosphate, can be used for introduction of phosphorus into the fluidized bed VPO-catalyst and as a result to increase the yield of maleic anhydride at a lower operating temperature and much lower concentrations of triethyl phosphate in comparison with the number of triethyl phosphate, which was required in previous methods, the introduction of triethyl phosphate in the vapor phase.

Usually alkilany ether phosphoric acid added to fluidized bed of catalyst in an amount of about 1-25 parts by weight Olkiluoto ether phosphoric acid Ala mass demotivational catalyst, preferably about 7-23 parts by weight Olkiluoto ester of orthophosphoric acid per 100 parts by weight of the catalyst; preferably about 8-21 parts by weight Olkiluoto ester of orthophosphoric acid per 100 parts by weight of the catalyst and more preferably about 16 to 19 parts by weight Olkiluoto ester of orthophosphoric acid per 100 parts by weight of the catalyst.

Abrasion resistant VPO-catalyst receiving maleic acid or maleic anhydride from hydrocarbons with 4 carbon atoms, such as n-butane, n-butenes, 1,3-butadiene or mixtures thereof, can be prepared as described in U.S. patent 4647673.

The catalyst may contain metal promoters. Metals such as Ti, Cr, W, TA, U, Co, Mo, Fe, Zn, Hf, Zr, Mn, As, Sb, Te, Bi, Sn, Ge, Nb, Ni, Cu, Cd, Th, CE, rare earths or mixtures thereof, can be added in the form of their compounds with vanadium or be entered separately in the solution. Metal promoters can be introduced into the catalyst in the form of soluble or insoluble metals, oxides, hydroxides, carbonates, or salts, such as halides, nitrates, acetates, formate, butyrate, benzilate, oxalates and tpet promoters can be introduced in the catalyst precursor by any means known in the art, such as flow through a liquid reaction medium before or after the recovery of vanadium or during one or more stages in which otopleniya catalyst for fluidized bed.

Predecessors of mixed vanadium-phosphorus oxide catalysts for oxidation of hydrocarbons can be prepared by methods known to experts in this field.

In U.S. patent 4002650 disclosed the preparation of catalysts containing mixed oxides of vanadium and phosphorus, the reaction of the compounds of vanadium and phosphorus in aqueous solution using Hcl as solvotrode reagent and a reducing agent for vanadium. Such methods of preparation are described in European patent application 3431, which revealed additional crushing vanadium-phosphate precursor to a particle size of 500-700 microns (0.5-0.7 mm).

In U.S. patent 4043943 disclosed the preparation of catalyst precursor in a liquid organic medium, preferably anhydrous, in which the connection of the vanadium is recovered and collaterals gaseous Hcl with subsequent reaction with a compound of phosphorus.

Preparation of catalysts oxylene containing mixed oxides of vanadium and phosphorus, are disclosed in U.S. patent 4244879, in which the connection of the vanadium is at least partially dissolved in the organic liquid medium capable of restoring at least a portion of the vanadium to the degree of oxidation of +4, and not dissolved vanadium in the form of particles of diameter greater than about 0.1 mm are removed from the reaction medium prior to the introduction of phosphate is about connection. The preparation of such catalysts are disclosed in U.S. patent 4333853, where reconnection of pentavalent vanadium effectively influenced by the presence of phosphorus compounds in a liquid organic medium, is able to recover vanadium.

The catalyst precursor can be isolated from the liquid reaction medium in which it was prepared (preferably remaining anhydrous organic liquid medium) by conventional methods such as evaporation, filtration, centrifugation, decantation and the like, it is Preferable that the precursor was dried by heating. Alternatively, the selected predecessor, which is still moist organic liquid, you can handle the low-boiling solvent such as petroleum ether. In another embodiment, excess reaction medium can be almost completely removed by vacuum filtration. In yet another embodiment, the precursor containing organic liquid reaction medium, water can be added, to give an organic layer to separate from the aqueous layer and then select the catalyst precursor by drying.

After separating the catalyst precursor is compacted and milled. The order in which the catalyst precursor is compacted and crushed, depends on the selected method. For example, the catalyst precursor can be sealed tablete what Finance, then crush or grind the concentration of the substance for the preparation of its formation microspheroidal particles. Alternatively, the catalyst precursor can be distinguished by drying or spray drying, and then grind in a ball mill with simultaneous compaction and crushing substances predecessor to particles with an average diameter of less than about 1 μm. Stage compaction and pulverization of the catalyst precursor can be repeated, so that the particles of the obtained catalyst for fluidized bed had a bulk density equal to or greater than about 0.75 g/cm3preferably greater than or equal to 1 g/cm3.

Compacted crushed catalyst precursor is then formed into microspheroidal particles, able to work in a fluidized mode. Shaping is possible by way of "a drop in oil" (oil drop), in which an aqueous solution of the catalyst precursor is added dropwise into a hot oil bath with the formation of spheroidal particles. It is preferable to obtain microspheroidal particles, able to work in the boiling mode, the spray drying of the aqueous slurry of the catalyst precursor.

A method of producing particles, able to work in a fluidized mode, crushing and sieving to obtain fractions suitable for use in the boiling mode is not suitable for obtaining the of utilizatorul, resistant to abrasion, because the particles are easily abraded when boiling primarily due to an irregular surface texture. For the same reason, the catalysts resulting from the crushing and sieving, also more susceptible to cracking.

When using spray drying preferably, the catalyst precursor with the introduction of water with the formation of the aqueous slurry was ' green'. When contacting the calcined mixed vanadium-phosphorus oxides with water (at a temperature below 100°C) the activity of the catalyst decreases, especially if it was progulivali in the air.

The solids content in the catalyst precursor, which is an aqueous suspension should be brought to about 25-60 wt.%, preferably above about 40 wt.%. The aqueous suspension containing the catalyst precursor, and then dried with raspisanie with the formation of a homogeneous microspheroidal particle size of about 20-300 μm, usually 20-240 μm. Spray drying can be carried out by methods known in this field.

The catalyst for fluidized bed can be added inert diluents or carriers prior to or during any stage of compaction, crushing and education microspheroidal particles, able to work in a fluidized mode. Such inert diluents and and carriers may include silicon oxide, aluminium oxide, aluminium silicate, titanium oxide, niobium oxide, silicon carbide, etc.

This method of making abrasion-resistant catalyst, however, is not limited only to add abrasion resistant media for imparting catalyst abrasion resistance. A special combination of stages of the present invention leads to the formation of abrasion-resistant catalyst, in which the content of the inert carriers can be extremely low or they will be missing. Typically, the catalysts of the present invention include at least 70% of the active substance. The catalyst is resistant to abrasion and is suitable for operation in a fluidized bed, which is preferably used in the present invention contains at least 80% active ingredient and most preferably at least 90% of the active substance.

Prepared as described above, particles, able to work in a fluidized mode, calcined under conditions of boiling regime. Specialists in this field can easily determine the conditions of the boiling regime, which include the submission of a gas flow in the vessel fluidized bed containing catalyst sufficient to "raise" the catalyst layer and the contact almost all of the catalyst particles from gaseous raw materials while maintaining isothermal temperature regime. The other is their method of calcination, such as cascade annealing, which, as the calcination in a fluidized mode, includes uniform contacting of the catalyst particles with a gas and maintaining a relatively isothermal temperature regime, can also be used in the present invention, and they lead to the boil, enough to give a calcined catalyst of resistance to abrasion. However, the calcination in a fluidized bed still preferable.

The catalyst was calcined in air or in oxygen-containing gas at conditions close to the boiling point in the temperature range of about 300-450°C. Optionally, the catalyst can be calcined in the presence of hydrocarbon, inert gas, water vapor or both. It is preferable to gradually increase the temperature of annealing from about 300°C to about 325°C., then to about 400-425°C, preferably at about 0.5-5°C per minute. The time of annealing depends on the method of preparation of the catalyst composition and quantity of catalyst, but usually, the calcination is carried out in a period of time greater than 1 hour.

The catalyst precursor may contain promoters, including, but not limited to, alkali metals, alkaline earth metals, Ti, Cr, W, TA, U, Co, Mo, Fe, Zn, Hf, Zr, Mn, As, Sb, Te, Bi, Sn, Ge, Nb, Ni, Cu, Cd, CE, rare earths or mixtures thereof. You can enter them in the predecessor rolled atora by any means, known in this field, such as the introduction through the liquid reaction medium before or after the recovery of vanadium or during one or more stages of the preparation of the catalyst to the fluidized bed. Promoters can be introduced into the catalyst in the form of soluble or insoluble metals, oxides, hydroxides, carbonates, or salts, such as halides, nitrates, acetates, formate, butyrate, benzilate, oxalates, etc. These promoters can be introduced in the catalyst precursor by any means known in this field, such as the introduction through the liquid reaction medium before or after the recovery of vanadium or during one or more stages of the preparation of the catalyst to the fluidized bed. The molar ratio of promoter and vanadium is typically from about 0.0001:1 to about 1:1, preferably from about 0.001:1 to about 0.2:1.

The catalysts of receipt of maleic anhydride from hydrocarbons with 4 carbon atoms characterized by the ratio of phosphorus to vanadium is from about 2:1 to about 0.5:1, preferably from about 0.8:1 to about 1.3:1. Most preferred is a ratio P/V, from about 1:1 to about 1.25:1. In these catalysts, the average valence of the vanadium is in the range from +3.5 to +4.6, preferably about +4.

The catalyst for fluidized bed used in this izaberete the AI, can be used in the oxidation reactors fixed bed, well-known in this field.

Hydrocarbons, which can turn into maleic anhydride, include n-butane, n-butenes, 1,3-butadiene or a mixture thereof. It is preferable to use n-butane or a mixture of hydrocarbons contained in the process flows of oil. Traditionally, air quality add molecular oxygen, but can be applied to the threads of the synthesis containing molecular oxygen. In addition to the hydrocarbon and molecular oxygen can be added to raw materials other gases. For example, reagents can be added water vapor or nitrogen.

The ratio of reactants can vary widely and is not critical. The preferred ratio of oxygen/hydrocarbon raw materials for reactor are approximately 4-20 moles of oxygen per mole of hydrocarbon.

The reaction temperature may be within wide limits and depends on the hydrocarbon and catalyst. Usually the preferred temperature of about 325-500°C and above, the preferred temperature is about 360-460°C. the Reaction can be conducted at atmospheric pressure, at pressures above and below atmospheric, although it is preferable to work at a pressure above atmospheric. Usually the raw material contains about 0.2-5.0 mol.% butane, preferably the use is but 1.0-4.0 mol.% butane mass flow rate of butane (wwh) is about 0.005-0.2 pounds of butane per pound of catalyst per hour, preferably about 0.01-0.1 pounds of butane per pound of catalyst per hour.

Advantages ways oxidation of hydrocarbons in a fluidized layer in comparison with the methods of oxidation of hydrocarbons in a fixed bed is well known to specialists in this field and include better temperature control and heat transfer in the oxidation reactions. However, the catalysts which can be used in methods with a fixed layer, not necessarily suitable ways fluidized bed. Catalysts suitable for methods with a fixed layer which are slightly worn due to abrasion, can be too soft to withstand the wear when working in a fluidized bed.

Catalyst attrition when working in a fluidized bed, i.e. removing the outer layer of the catalyst particles as a result of friction or fracture or cracking caused by particles in the fluidized layer at each other, the walls of the vessel fluidized bed, especially in the reactor cyclone type, which capture particles fluidized catalyst before they leave the reactor, and return the particles in the catalyst layer.

Catalysts containing the oxides of vanadium and phosphorus, used in the oxidation of hydrocarbons with 4 carbon atoms, such as n-butane, n-butenes, 1,3-butadiene or mixtures thereof with molecular oxygen or oxygen-containing gas with the formation of the maleic anhydride. Traditional methods of preparing such catalysts include the reduction of compound of pentavalent vanadium and combining it with a compound of phosphorus and optionally compounds of promoters under conditions that lead to vanadium in a valence state below +5 with the formation of precursors of catalysts, capable of being converted into oxide. Oxide catalyst precursor is then isolated and converted into an active catalyst before or after formation of the catalyst particles of the desired size for either the fixed layer or fluidized bed.

In U.S. patent 3888886; 3905914; 3931046; 3932305 and 3975300 disclosed checked oxide promoted vanadium-phosphorus catalysts receipt of maleic anhydride from butane in the reactor with a diameter of one inch with a fixed catalyst bed. In many cases, the catalysts were prepared by forming a catalyst precursor in aqueous media (3975300 predecessor received in the form of paste, vanadium compounds, phosphorus compounds and organic reductant), drying and then grinding and sieving predecessor to powder with a particle size of about 74-250 μm. This method, however, does not allow to obtain the abrasion resistant particles of catalyst required for the successful operation of fluidized bed.

Preferably, when Islandia catalysts for fluidized bed are microspheroidal particles with an average diameter of about 20-300 μm, preferably containing about 80% of particles with diameter in the range of about 30-80 μm. Most preferably, about 25-40% of the particles had an average diameter less than 45 microns.

While preferred are catalysts that are resistant to abrasion, in the present invention to obtain a maleic acid or maleic anhydride from hydrocarbons with 4 carbon atoms can be used any vanadium-phosphorus oxide catalyst suitable for operation in a fluidized bed, with the addition of phosphorus to the catalyst during the reaction. VPO catalyst is saturated alkilany the orthophosphate ester such as triethyl phosphate, and then add in the boiling layer parts, which are necessary for a quantitative introduction of phosphorus.

Therefore, the aim of the invention is to provide a method of making abrasion-resistant oxidation catalysts in a fluidized bed containing mixed oxides of vanadium and phosphorus, which are enriched alkilany the orthophosphate ester such as triethyl phosphate.

VPO-obtain catalysts in a fluidized bed of maleic anhydride from hydrocarbons with 4 carbon atoms can be activated by contacting the catalysts containing mixed oxides of vanadium and phosphorus, in a fluidized bed with oxygen and gas-reducing agent, which at least partially can burn under the action of the oxygen at elevated temperatures, enough for combustion, and the molar ratio of a reducing gas and oxygen in a stoichiometric ratio required for complete combustion of a reducing gas as described in U.S. patent 4748140.

The catalyst can be activated before loading into the reactor or after loading into the reactor.

The present invention has the advantage that allows you to precisely adjust the amount of added phosphorus. Using the present invention, it is possible to add phosphorus quantitatively.

Description of the method

1. TER-enriched VPO catalyst is prepared by impregnation at room temperature powder catalyst by triethyl phosphate at concentrations in the range of about 1-25 parts by weight per 100 parts by weight of raw catalyst, preferably about 7-23 parts by weight per 100 parts by weight of the catalyst, more preferably about 8-21 parts by weight per 100 parts by weight of the catalyst and even more preferably about 16 to 19 parts by weight per 100 parts by weight of the catalyst.

Although it is possible to obtain a concentration higher than 25 parts by weight per 100 parts by weight of raw catalyst powder enriched TER VPO catalyst may be too wet, which will complicate the handling and processing; however, if the treatment can be carried out, can be used and the concentration of the emission above 25 parts by weight per 100 parts by weight of raw catalyst.

2. TER-enriched catalyst add parts to the catalyst in the fluidized bed reactor. In industrial reactors with a fluidized bed catalyst is usually added through a tube for supplying catalyst to the bottom of the reactor. The stream of fluidized catalyst is directed upwards, and TER-enriched catalyst introduced through the catalyst tube is drawn into the stream and is mixed with the catalyst in a fluidized bed.

3. It was found that among the studied several ways of introducing TER-enriched catalyst is the most effective direct introduction of the powder catalyst under operating conditions.

4. On the basis of laboratory studies of the effect of temperature and time loss TER of the powder catalyst enriched TER, it is estimated that in the pilot reactor is only about 75% TER emitted from enriched TER catalyst may enter into the composition of the catalyst, as TER-enriched catalyst is added when the catalyst stream is stopped. I believe that the remaining number of available TER is lost with the exhaust gas flow.

The number of TER, which impose a TER-enriched catalyst for increasing the activity of the catalyst may vary depending on the number of TER absorbed VPO-catalyst. Regardless of the concentration TER in TER-enriched kata is isatori to improve catalytic activity, it is important to add enough TER. Therefore, to improve catalytic activity to highlight the TER in sufficient quantities it is necessary to add a sufficient amount of saturated TER catalyst. The number of TER suitable for increasing the activity VPO-catalyst shown in the following intervals TER, expressed in pounds TER 100 pounds just a layer of catalyst per night: from about 0.000002 to about 1.0, more preferably about from about 0.00002 to about 0.2, and most preferably from about 0.0002 to about 0.04 pounds.

Thus, TER-soaked VPO catalyst added to the reactor to allocate approximately 0.000002-1.0 pounds TER 100 pounds just a layer of catalyst per day, preferably about 0.00002-0.2 pounds TER 100 pounds just a layer of catalyst per day and more preferably about 0.0002-0.04 pounds TER 100 pounds just a layer of catalyst per day.

For example, in the case when the powder enriched TER catalyst is mixed with powder of a catalyst which has not been impregnated TER (i.e. designated as catalyst without TER or unenriched catalyst) prior to the filing of the mixture in the reactor, the powder TER-enriched catalyst used in the mixture of catalysts can be soaked more than 25 parts TER mass. In this embodiment, TER-enriched catalyst is impregnated with so many TER, which is quite the La achieve a concentration of approximately 0.000002-1.0 pounds TER 100 pounds just a layer of catalyst per day, when boiling a mixture of TER-enriched catalyst and catalyst without TER is added to the reactor. When feeding to the reactor a mixture of TER-enriched catalyst and catalyst without TER contains approximately 0.00002-0.2 pounds TER 100 pounds just a layer of catalyst per day and most preferably about 0.0002-0.04 pounds TER 100 pounds just a layer of catalyst per day.

Maleic anhydride can be distinguished in many ways, well known to specialists in this field. For example, it is possible to allocate direct condensation or by absorption in suitable media and purification of maleic anhydride.

EXAMPLES

It must be borne in mind that this invention is not limited to the following examples. They are given only to demonstrate the fitness for use, and from open General descriptions you can choose the catalysts, sources of metals, coal carriers, concentrations, contact times, loading of solid substances, raw materials, reaction conditions, and products, if you do not deviate from the spirit and scope of the disclosed and the invention including modifications and variations that fall within the scope of the claims.

The experiments in Example 1 were carried out in 1.5-inch pilot fluidized bed reactor. Due to the logistical constraints on pilot plant fluidized bed when the content of butane in raw materials in the amount of 0.2-5 m the l% and the mass flow rate of butane 0.005-0.2 parts by weight of butane to 1 part by weight of catalyst per hour, you need to add enriched catalyst portions on top of the deposited layer of the catalyst at high operating temperature. Because the flow of the air/butane in the reactor is directed upwards, the authors expected that part of the TER will evaporate from the TER-enriched catalyst and, therefore, will not be able to interact with the catalyst bed. The authors found that in the reactor pilot plant approximately 25% TER is lost when the catalyst is added on top of the settled catalyst layer. Therefore, in the layer of catalyst for this reaction can get about 75% TER out TER-enriched catalyst.

In larger industrial reactor no logistical constraints when adding TER-enriched catalyst and it can be added either continuously or in portions. Moreover, in larger scale industrial reactor TER-enriched catalyst can be served in the lower part of the catalyst layer and, therefore, all TER enters the catalyst bed. TER-enriched catalyst can be added continuously in the form of one or more portions per day. For example, if you want to add 400 pounds TER-enriched catalyst to the catalyst in a fluidized bed, 400 pounds TER-enriched catalyst can be added continuously for 24 hours at a given speed, or 400 pounds TER-enriched catalyst can be added in one aliquot in a short period of time, say, for 20 minutes Alternative, 400 pounds on Ogadenia TER-enriched can be added in several portions during for example, one or more hours or during the day.

The number of pounds TER 100 pounds of catalyst per day, which is used in the practice of this invention, approximately 0.000002-1.0 pounds TER 100 pounds of catalyst per day, preferably about 0.00002-0.2 pounds TER 100 pounds of catalyst per day, more preferably about 0.0002-0.04 pounds TER 100 pounds of catalyst per day.

In one embodiment of the invention the catalyst fluidized bed containing alkilany ether phosphoric acid, is added in a quantity sufficient to limit the total lifting of the working temperature is not more than about 20°C. Preferably, the catalyst fluidized bed containing alkilany ether orthophosphoric acid was added in a quantity sufficient to limit the total lifting of the working temperature is not more than about 15°C., and more preferably, the catalyst fluidized bed containing alkilany ether orthophosphoric acid was added in a quantity sufficient to limit the total lifting of the working temperature is not more than about 10°C.

EXAMPLE 1

Adding TER-enriched catalyst

A. Adding triethyl phosphate (TER) for catalyst

Prepared two samples TER-enriched catalyst with nominal concentrations of 10 and 15 wt.% accordingly the public. For the sample with a nominal concentration of 10 wt.% added 20 parts by weight of liquid triethyl phosphate to 200 parts by mass, VPO-catalyst. For the sample with a nominal concentration of 15 wt.% added 30 parts by weight of liquid triethyl phosphate to 200 parts by mass, VPO-catalyst. After adding triethyl phosphate powder catalyst was stirred for several minutes to achieve a uniform distribution of triethyl phosphate in the catalyst.

C. Testing activity

The influence of additives TER-enriched catalyst was studied in a 1.5-inch pilot reactor under the following conditions: the ratio of the air/butane 30/1, mass feed rate (wwh) of 0.05 and a pressure of 10 pounds per square inch. Before adding TER-enriched catalyst reactor worked with the loaded catalyst for several days without adding TER in order to make sure that the catalyst removed all the excess phosphorus. Then the layer of catalyst at 370 g for 2 days added two portions 4 g powder, enriched with 10% TER. TER-obogashenii powder was added to the settled catalyst layer when air supply is shut off/butane gas at the reaction temperature. The powder is pneumatically transferred from the vessel for the introduction of solids under pressure, which was associated with entrance into the upper part of the reactor. According to our assumption that the pilot Rea the Torah 25% TER is lost without contact with the catalyst, this would be consistent with the effective introduction of 3 g/day (0.81% of the total layer) this enriched powder.

Data on the yield of maleic anhydride and the temperature dependence of the activity as a result of the addition of phosphorus with the introduction of TER-soaked VPO catalyst are shown in table 1. Output in the presence of the catalyst increased from 43.7 mol.% to about 51 mol.% or, the increase amounted to about 7 mol.%. Although the temperature was raised once a day at 11°F (6.1°C), the temperature was rapidly decreased as the number of added phosphorus began to decline. After 5 days of work output decreased to 46.7 mol.%, but still remained above the initial output 43.6 mol.%. The experience continued, periodically adding powder TER-enriched VPO catalyst, within the next 14 days. The data clearly show that the output remained at the level of 51 mol.% or more during the entire period when the total increase in operating temperature by approximately 10°F (approximately 5.6°C) from the starting point.

Table 1
The influence of additives TER-soaked VPO catalyst on the catalyst activity
the
LayerLayerEnriched with 10% TEREnriched with 15% TER
TimeTemperatureMANTemperatureThe additive catalystThe additive catalyst
hour°COutput %°Fgramsgrams
245648.5853
7544944.5840
14444943.6840
148 4
16845248.1846
1724
18745650.8853
21545049.0842
26545146.9844
30944845.2838
3133
33945448.1849
3431.5
35945552.2851
3631.5
38145452.4849
3852
40845652.4853
44045150.8 844
45845449.2849
4621.5
47945650.3853
4833
53045952.5858
53445253.4846
5381.5
55344553.7833
5571.5
57744652.3835
5811.5
60144652.8835
6052
62644653.2835
630 1.5
6541.5
674 45551.5851

Comparative example a

Standard test introduction TER-vapor introduction of triethyl phosphate in raw materials for reactor

The influence of continuous introduction into the reactor additives TER in the form of steam to the gas of the raw material studied in 1.5-inch pilot fluidized bed reactor under the following conditions: the ratio of the air/butane 30/1, wwh Bhutan 0.05 and a pressure of 10 pounds per square inch. TER served continuously in the form of 0.33 wt.% TER aqueous solution in an air-line feed with a speed of 1.8 g/hour to achieve a constant steam concentration of 20 ppm TER in gaseous raw materials for the reactor. The air line feeding the feedstock into the reactor pre-warmed up to reactor temperature until complete evaporation of the aqueous solution of TER. Before the introduction of 20 ppm, a pair of TER in the reactor the catalyst was tested without TER for 150 hours for removal of the catalyst of excess phosphorus. Then began filing TER in the amount of 20 ppm and continued for about 200 h the with to determine its effect on the catalyst.

Table 2
The influence of the vapor of the introduction of 20 ppm TER for the active VPO-catalyst
LayerLayer
TimeTemperatureMANTemperature
(Watch)°COutput %°F
2644647.3835
7244847.4838
12044246.3828
14744346.3829
19144848.7838
215449 48.6840
23945547.7851
26145547.8851
28745947.1858
31245950.4858
35745948.1858

Table 2 shows the data of comparative example A, which was introduced a standard additive TER in the vapor phase in air flow MAN fluidized bed reactor. The data in table 2 show that odnovremenno introduction TER in the vapor phase has resulted only in increasing the yield of the MAN about 3-4 mol.% and caused a significantly greater increase in temperature of about 30°F (16.7°C) compared to the initial temperature.

It is obvious that the introduction of TER by adding TER-impregnated catalyst VPO provides more advantages than the former practice of adding TER in the vapor phase in air flow in MAN-fluidized bed reactor.

1. The method of obtaining maleic anhydride is a fluidized bed oxidation of raw materials, containing hydrocarbons With4molecular oxygen or oxygen-containing gas in a fluidized bed reactor at a temperature of reactor 325-500°C in the presence able to work in a fluidized-bed catalyst containing mixed oxides of vanadium and phosphorus, the catalyst is prepared as follows:
(a) preparation of catalyst precursor containing a mixed oxide of vanadium and phosphorus;
(b) sealing catalyst precursor;
(c) crushing of the catalyst precursor to particles of average size less than one micron in diameter;
(d) forming particles, able to work in a fluidized bed, with a bulk density greater than or equal to 0.75 g/cm3of compacted crushed catalyst precursor; and
(e) calcination in a fluidized mode particles, able to work in a fluidized bed,
in which the output of maleic anhydride increases by adding the compensating catalyst in a fluidized bed reactor, and this compensates the catalyst contains alkilany ether orthophosphoric acid of the formula (RO)3P=O, where R is hydrogen or alkyl With1-C4and at least one R is alkyl (C1-C4and compensating the catalyst is prepared by impregnation of the catalyst obtained in accordance with the stages (a) through (e) alkylbis firom orthophosphoric acid.

2. The method according to claim 1, in which alkilany ester is triethyl phosphate.

3. The method according to claim 1, in which alkilany ether is trimethylphosphate.

4. The method according to claim 1, in which able to work under boiling catalyst additionally contains at least one promoter selected from the group consisting of alkali metals, alkaline earth metals, Ti, Cr, W, TA, U, Co, Mo, Fe, Zn, Hf, Zr, Mn, As, Sb, Te, Bi, Sn, Ge, Nb, Ni, Cu, Cd, Th, CE, rare earth elements, or mixtures thereof.

5. The method according to claim 1, wherein the reaction temperature is 360-460°C.

6. The method according to claim 1, wherein compensating the catalyst containing alkilany ether phosphoric acid, is added in a quantity sufficient to limit the total rise of the working temperature is not more than 20°C.

7. The method according to claim 1, wherein compensating the catalyst containing alkilany ether phosphoric acid, is added in a quantity sufficient to limit the total rise operating temperature not more than 15°C.

8. The method according to claim 1, wherein compensating the catalyst containing alkilany ether phosphoric acid, is added in a quantity sufficient to limit the total rise of the working temperature is not more than 10°C.

9. The method according to claim 1, in which alkilany ester of orthophosphoric acid is triethyl phosphate, and to compensate for yuushi catalyst, containing triethyl phosphate, is added in a quantity sufficient to limit the total rise of the working temperature is not more than 20°C.

10. The method of obtaining maleic anhydride in a fluidized bed oxidation of a feedstock containing hydrocarbons With4molecular oxygen or oxygen-containing gas in a fluidized bed reactor at a temperature of reactor 325-500°C in the presence able to work in a fluidized-bed catalyst containing mixed oxides of vanadium and phosphorus, the catalyst is prepared as follows:
(a) preparation of catalyst precursor containing a mixed oxide of vanadium and phosphorus;
(b) sealing catalyst precursor;
(c) crushing of the catalyst precursor to particles of average size less than one micron in diameter;
(d) forming particles, able to work in a fluidized bed, with a bulk density greater than or equal to 0.75 g/cm3of compacted crushed catalyst precursor; and
(e) annealing under conditions of boiling mode particles, able to work in a fluidized bed, in which the output of maleic anhydride with this method improve when adding the compensating catalyst in a fluidized bed reactor, and compensating the catalyst contains 1-25 parts by weight Olkiluoto ether orthophosphoric acid of the formula (O) 3P=O, where R is hydrogen or alkyl (C1-C4and at least one R is alkyl (C1-C4on 100 parts by weight of the catalyst, and compensating the catalyst is prepared by impregnation of the catalyst obtained in accordance with the stages (a) through (e) alkylbis ether orthophosphoric acid.

11. The method according to claim 10, in which alkilany ester is triethyl phosphate.

12. The method according to claim 10, in which alkilany ether is trimethylphosphate.

13. The method according to claim 10, in which the raw material contains 0.2 to 5.0 mol.% butane and mass hourly space velocity of Bhutan is from 0.005 to 0.2 parts by weight of butane to 1 part by weight of catalyst per hour.

14. The method according to item 13, in which alkilany ester is triethyl phosphate, and compensating the catalyst contains 7-23 parts by weight of triethyl phosphate to 100 parts by weight of the catalyst.

15. The method according to claim 10, in which alkilany ester is triethyl phosphate, and compensating the catalyst contains from 16 to 19 parts by weight of triethyl phosphate to 100 parts by weight of the catalyst.

16. The method according to claim 10, in which is able to work in the boiling mode, the catalyst additionally contains at least one promoter selected from the group consisting of alkali metals, alkaline earth metals, Ti, CR, W, TA, U, Co, Mo, Fe, Zn, Hf, Zr, Mn, As, Sb, Te, Bi, Sn, Ge, Nb, Ni, Cu, Cd, Th, CE, rare earth element is at or mixtures thereof.

17. The method according to claim 10, in which the reaction temperature is 360-460°C.

18. The method according to claim 10, in which the compensating catalyst containing 1-25 parts by weight Olkiluoto ester of orthophosphoric acid per 100 parts by weight of the catalyst, is added in a quantity sufficient to limit the total rise of the working temperature is not more than 20°C.

19. The method according to p, which compensates the catalyst contains 1-25 parts by weight of triethyl phosphate to 100 parts by weight of the catalyst.

20. The method according to claim 19, in which the compensating catalyst containing 1-25 parts by weight of triethyl phosphate to 100 parts by weight of the catalyst, is added in a quantity sufficient to limit the total rise operating temperature not more than 15°C.

21. The method according to claim 19, in which the compensating catalyst containing 1-25 parts by weight of triethyl phosphate to 100 parts by weight of the catalyst, is added in a quantity sufficient to limit the total rise of the working temperature is not more than 10°C.

22. Able to work in a fluidized mode catalyst to obtain a maleic anhydride by oxidation of a raw material containing a hydrocarbon, C4with molecular oxygen or oxygen containing gas in a fluidized bed reactor at a temperature of reactor 325-500°C, containing mixed oxides is Anadia and phosphorus, moreover, the catalyst is prepared as follows:
(a) preparation of catalyst precursor containing a mixed oxide of vanadium and phosphorus;
(b) sealing catalyst precursor;
(c) crushing of the catalyst precursor to particles of average size less than one micron in diameter;
(d) forming particles, able to work in a fluidized bed, with a bulk density greater than or equal to 0.75 g/cm3of compacted crushed catalyst precursor; and
(e) annealing under conditions of boiling mode particles, able to work in a fluidized bed, and
(f) mixing calcinatory able to work in a fluidized mode particles obtained in stage (e), with alkilany ether orthophosphoric acid of the formula (RO)3P=O, where R is hydrogen or alkyl With1-C4and at least one R is alkyl (C1-C4with the formation of the catalyst containing 1-25 parts by weight Olkiluoto ester of orthophosphoric acid per 100 parts by weight of the catalyst.

23. The catalyst according to item 22, containing 7-23 parts by weight Olkiluoto ester of orthophosphoric acid per 100 parts by weight of the catalyst.

24. The catalyst according to item 22, containing 8-21 parts by weight Olkiluoto ester of orthophosphoric acid per 100 parts by weight of the catalyst.

25. The catalyst according to item 22, containing 16 to 19 parts by weight Alki the new ester of orthophosphoric acid per 100 parts by weight of the catalyst.

26. The catalyst according to item 22, additionally containing at least one promoter selected from the group consisting of alkali metals, alkaline earth metals, Ti, Cr, W, TA, U, Co, Mo, Fe, Zn, Hf, Zr, Mn, As, Sb, Te, Bi, Sn, Ge, Nb, Ni, Cu, Cd, Th, CE, rare earth elements, or mixtures thereof.

27. Able to work in a fluidized bed of catalyst to obtain a maleic anhydride by oxidation of a feedstock containing hydrocarbons With4with molecular oxygen or oxygen containing gas in a fluidized bed reactor at a temperature of reactor 325-500°C, containing mixed oxides of vanadium and phosphorus, the catalyst is prepared as follows:
(a) preparation of catalyst precursor containing a mixed oxide of vanadium and phosphorus;
(b) sealing catalyst precursor;
(c) crushing of the catalyst precursor to particles of average size less than one micron in diameter;
(d) forming particles, able to work in a fluidized bed, with a bulk density greater than or equal to 0.75 g/cm3of compacted crushed catalyst precursor; and
(e) annealing under conditions of boiling mode particles, able to work in a fluidized bed, and
(f) mixing calcinatory able to work in a fluidized mode particles obtained in stage (e), triethyl phosphate with the formation able to work in a fluidized with the second catalyst, containing 1-25 parts by weight of triethyl phosphate to 100 parts by weight of the catalyst.

28. The catalyst according to item 27, containing 7-23 parts by weight of triethyl phosphate to 100 parts by weight of the catalyst.

29. The catalyst according to item 27, containing 8-21 parts by weight of triethyl phosphate to 100 parts by weight of the catalyst.

30. The catalyst according to item 27, containing 16 to 19 parts by weight of triethyl phosphate to 100 parts by weight of the catalyst.

31. The catalyst according to clause 29, additionally containing at least one promoter selected from the group consisting of alkali metals, alkaline earth metals, Ti, Cr, W, TA, U, Co, Mo, Fe, Zn, Hf, Zr, Mn, As, Sb, Te, Bi, Sn, Ge, Nb, Ni, Cu, Cd, Th, CE, rare earth elements, or mixtures thereof.



 

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13 cl, 1 tbl, 9 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a single-step method for vapour-phase oxidation of an alkane such as propane which leads to production of unsaturated caboxylic acid such as acrylic or methacrylic acid in the presence of a mixed metal oxide catalyst and excess alkane with respect to amount of oxygen. The method of producing unsaturated carboxylic acid involves: (a) reacting alkane and oxygen-containing gas in a reaction zone with a catalyst which contains mixed metal oxide under conditions which enable production of a gaseous product containing unsaturated carboxylic acid, unreacted alkane and an alkene by-product; (b) extraction of unreacted alkane and alkene by-product from the gaseous product; and (c) recycling the mixture of the extracted unreacted alkane and alkene by-product to the reaction zone without separating components; in which the mixed metal oxide consists of material with general formula MoVvAaBbCcOx where Mo is molybdenum, V is vanadium, each of A, B and C represents niobium, antimony, tellurium, silver, tantalum, titanium, aluminium, zirconium, chromium, manganese, iron, ruthenium, cobalt, rhodium, nickel, platinum, bismuth, boron, indium, arsenic, germanium, tin, lithium, sodium, potassium, rubidium, caesium, francium, beryllium, magnesium, calcium, stronium, barium, hafnium, lead, phosphorus, promethium, europium, gadolinium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, gold, selenium, palladium, gallium, zinc, praseodymium, rhenium, iridium, neodymium, yttrium, samarium and terbium, v equals 0.1-0.5, a equals 0.01-0.2, b equals 0.0-0.5, c equals 0.0-0.5, value of x is determined by valency of other components, in which alkane is propane or isobutane; where the alkane is in excess relative oxygen and molar ratio alkane: oxygen ranges from 3:1 to 1:1; and in which amount of alkene recycled to the reactor corresponds to the molar ratio alkane: alkene equal to 1:0.03-1:0.1.

EFFECT: improved method.

14 cl, 3 tbl, 1 dwg, 23 ex

FIELD: chemistry.

SUBSTANCE: invention relates to a thermal separation method using fractional condensation of a product-gas mixture, obtained through heterogeneous catalysed partial oxidation of propene and/or propane in gaseous phase to acrylic acid, for separating at least one mass flow, concentrated with acrylic acid, from a product-gas mixture containing acrylic acid, which involves continuous static operation of at least one device for thermal separation, containing at least one effective separation chamber with a fractionation column which has mass-transfer trays as built-in separating elements, in which the product-gas mixture is loaded, containing acrylic acid as at least one mass flow, and from which at least one mass flow containing acrylic acid is unloaded under the condition that, the overall mass flow loaded into the effective separation chamber and obtained from combining separate mass flows loaded into the separating chamber, contains X wt % components distinct from acrylic acid, the mass flow which is unloaded from the effective separation chamber with the largest content of acrylic acid, contains Y wt % components distinct from acrylic acid, ratio X:Y is ≥5, effective separation chamber, except the loading and unloading place, is bordered by a solid phase and contains, besides the mass-exchange trays as built-in separating elements in the fractionation column, at least one circulating heat exchanger, and total volume of the chamber, filled with liquid phase, is ≥1 m3, wherein temperature of the liquid phase is at least partially ≥80°C, when the effective separation chamber is divided into n separate volume elements, wherein the highest and lowest temperature of liquid phase in a separate volume element differ by not more than 2°C, and the volume element in the effective separation chamber is solid, total dwell time ttotal.

≤20 h, where A = (Ti-To)/10°C, To= 100°C, Ti = arithmetic mean value of the highest and lowest temperature of the ith volume element in the liquid phase in °C, msi = total mass of acrylic acid in the volume of the liquid phase of the ith volume element, mi = total liquid phase mass unloaded from the ith volume element, and is the sum of all volume elements i, under the condition that, volume elements i with liquid phase mass mi and as volume elements with a dead zone are also not included in the sum of all volume elements i, as well as volume elements i, which do not contain liquid phase, and total amount of liquid phase contained in volume elements with a dead zone is not more than 5 wt % of the total amount of liquid phase contained in the effective separation chamber.

EFFECT: separation of mass flow concentrated with acrylic acid.

10 cl, 12 dwg, 2 ex, 2 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to improvement of the method of producing (meth)acrylic acid or (meth)acrolein through gas-phase catalytic oxidation of at least one oxidisable substance, chosen from propylene, propane, isobutylene and (meth)acrolein, molecular oxygen or a gas, which contains molecular oxygen, using a multitubular reactor, with such a structure that, there are several reaction tubes, with one (or several) catalytic layer (catalytic layers) in the direction of the axis of the tube, and a coolant can flow outside the said reaction tubes so as to regulate temperature of reaction, in which temperature of the said reaction of gas-phase catalytic oxidation is increased by varying temperature of the coolant at the inlet for regulating temperature of the reaction, while (1) temperature of coolant at the inlet for regulating temperature of the reaction is varied by not more than 2°C for each variation as such, and (2) when variation is done continuously, the time interval from the variation operation, directly preceding the present, is not more than 10 minutes, and, in addition, the difference between the maximum value of peak temperature of reaction of the catalyst layer of the reaction tube and temperature of the coolant at the inlet for regulating temperature of reaction is not less than 20°C.

EFFECT: method in which sharp increase of temperature is suppressed even after changing reaction conditions with aim of increasing temperature for improving efficiency, thus preventing catalyst deactivation, and achieving stable output.

3 cl, 5 dwg, 5 ex

FIELD: chemistry.

SUBSTANCE: invention refers to the catalyst composition; to the method of its preparation and to the method of ethane and/or ethylene selective oxidation to acetic acid. The catalyst composition for ethane and/or ethylene selective oxidation to acetic acid on the carrier includes the following elements: molybdenum, vanadium, niobium and titanium in combination with oxygen corresponding to the empiric formula MoaTicVdNbeOx, where a, c, d, e are such gram-atomic element ratio whereat 0<a≤1; 0.05<c≤2; 0<d≤2; 0<e≤1 and x is element valency in the said composition. The described above catalyst composition includes the following stages: (a) preparation of the mixture containing molybdenum, vanadium, niobium and titanium in the solution; (b) drying of the obtained solid material and (c) calcination of the dried solid material with obtaining of the catalyst composition. The method of acetic acid selective preparation from the gaseous mixture containing ethane and/or ethylene includes contacting of the gaseous mixture with oxygen-containing gas at increased temperature in the presence of the described above catalyst composition.

EFFECT: increase of catalyst composition selectivity in relation to acetic acid.

22 cl, 3 tbl, 5 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing (met)acrolein and/or (met)acrylic acid through heterogeneous catalytic partial oxidation in gaseous phase, in which a fresh fixed-bed catalyst at 100-600°C in a reactor is loaded with a mixture of loading gas, which along with at least, one C3/C4 organic precursor compound subject to partial oxidation and oxidation with molecular oxygen, contains at least one gas-diluent. The process is carried out after establishing content of the mixture of loading gas at constant conversion of organic precursor compound and at constant content of the mixture of loading gas initially in the input period for 3-10 days with load of 40-80% of higher final load, and then at higher filling load of the catalyst with a mixture of loading gas. In the input period, maximum deviation of conversion of organic precursor compound from arithmetic time-averaged and maximum deviation of the volume ratio of one component of the mixture loading gas, oxidising agent, organic precursor compound and gas-diluent, from the arithmetic time-averaged volume ratio of the corresponding component of the mixture of loading gas should not exceed ±10% of the corresponding arithmetic mean value.

EFFECT: method allows for eliminating shortcomings of previous technical level.

3 cl, 1 ex

FIELD: chemistry.

SUBSTANCE: proposed is a method of oxidising alkane from C2 to C4, obtaining the corresponding alkene and carboxylic acid and/or oxidising alkene from C2 to C4, obtaining the corresponding carboxylic acid. The method involves addition into the reaction zone of the above mentioned alkane and/or alkene, containing molecular oxygen gas, carbon monoxide and optionally water, in the presence of a catalyst, effective for oxidising the alkane to the corresponding alkene and carboxylic acid and/or effective for oxidising the alkene to the corresponding carboxylic acid at temperature between 100 and 400 °C. Concentration of carbon monoxide is kept between 1 and 20% of the total volume of the initial material added to the oxidation reaction zone. The method can optionally involve further reaction in a second reaction zone.

EFFECT: new oxidation method for producing carboxylic acids and alkenes.

30 cl, 3 ex, 1 tbl, 2 dwg

FIELD: chemistry.

SUBSTANCE: present invention relates to an improved method of producing at least one product of partial oxidation and/or ammoxidation of a hydrocarbon, chosen from a group containing acrolein, acrylic acid, methacrolen, methacrylic acid, acrylonitrile and methacrylonitrile. At least one saturated hydrocarbon is subjected to heterogeneous catalysed dehydrogenation in a gas phase, obtaining a gas mixture, containing at least one partially dehydrogenated hydrocarbon. Components of the gas mixture except saturated hydrocarbon and partially dehydrogenated hydrocarbon are left in the mixture. Alternatively, the extra gas mixture obtained is partially or completely separated, and the gas mixture and/or extra gas mixture are used for obtaining another gas mixture, containing molecular oxygen and/or molecular oxygen and ammonia. This gas mixture is subjected to at least single heterogeneous catalysed partial oxidation and/or ammoxidation of at least one partially dehydrogenated hydrocarbon contained in the gas mixture and/or extra gas mixture. The gas mixture, extra gas mixture and/or the other gas mixture, before at least one partial heterogeneous catalysed oxidation and/or ammoxidation, are subjected to at least a single mechanical separation, aimed at separating particles of solid substance contained in the above mentioned gas mixtures.

EFFECT: reliable and continuous realisation of the process for relatively long periods of time.

6 cl, 1 ex

FIELD: process engineering.

SUBSTANCE: invention relates to hydraulic treatment catalysts and methods of their production. Proposed method comprises: (I) using, at least, on of the following components: (A) one calcinated porous carrier; (B) catalytically active metals used in hydrocarbon hydraulic treatment, at least, one metal of VIB group of periodic table, and, at least one component including, at least, one metal of VIII group of periodic table; (C) at least, one chelate; (D) water in amount sufficient for producing solution or dispersion containing said catalytically active metals and at least, one said chelate; (II) interaction of said components (1)(A) with said solution or dispersion containing (1)(B) and (1)(C) during time interval and at temperature sufficient for mix production and impregnation of said carrier with said components (1)(B) and (1)(C) (III) to make the volume of said solution or dispersion equal to or exceeding water porosity of said carrier by separating said impregnated carrier from solution or dispersion volume that exceeds water porosity volume; and (IV) heating said impregnated carrier to above 200°C, and lower temperature and time period that may cause notable destruction of, at least, one said chelate.

EFFECT: chelated hydraulic treatment catalyst with low moisture content.

18 cl, 8 tbl, 5 ex

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