DE2641413A1 - Acrylonitrile prodn. using mixed metal catalyst - by reacting propylene with oxygen and ammonia - Google Patents

Abstract

The process comprises reacting propylene with oxygen and ammonia in the vapour phase in the presence of a catalyst of formula MoaCobFecXdOe which have been calcined at 550-700 degrees C. In the formula X is P, As, Sb or Bi; A,b,c,d,e is atomic ratio, when a is 12, b is 4-9, c 1-5, d 0.01-0.07 and e is decided by the valence of the elements except for oxygen, and is 39.5 to 52.7. Requirement of heat for the reaction is low, and the catalyst has a long life. Acrylonitrile is produced in a yield of >80% and there is little byprod. formation.

Description

Process for the production of acrylonitrile

The invention relates to a method for producing acrylonitrile through the catalytic conversion of propylene with ammonia and molecular oxygen in the gas phase at elevated temperature.

Different processes for making acrylonitrile by merging of propylene with oxygen and ammonia in the gas phase in the presence of a catalyst at elevated temperature are known. Likewise are different types of catalysts known for this procedure. The common types of catalysts mainly exist from mixtures of oxides that contain combinations of oxides of several elements. Many of the usual catalysts contain bismuth and molybdenum as catalyst components. For example, Japanese Patent Application Laid-Open No. 36-5870 (1961) describes one P-Mo-Bi-O catalyst, Japanese Patent Application Laid-Open No. 38-17967 (1963) an Fe-Bi-Mo-P-O catalyst, Japanese Patent Application Laid-Open No. 45-35287 (1970) discloses a P-Mo-Bi-Fe-Co-Ni-O catalyst Japanese Patent Application Laid-Open No. 49-4209 (1974) describes a Tl-Mo-Fe-Bi-X-P catalyst, in which X is a magnesium, cobalt or nickel atom, the Japanese laid-open publication No. 47-17718 (1972) a Mo-Bi-Fe Mg-P-O catalyst and the Japanese Laid-Open Publication No. 48-49719 (1973) discloses a Mo-Bi-Fe-Co-O catalyst. The usage of the usual types of catalysts for the production of acrylonitrile - but has the the following disadvantages: -1) The reaction must take place at a relatively high temperature of about 4500C or higher. -2). -The use for the reaction must be kept in contact with the catalyst for a long time in order to achieve the Complete response. 3) The yield of acrylonitrile per unit of time and per unit of quantity of the catalyst is relatively low. Furthermore, the. common types of catalysts the disadvantage that the catalyst cost is relatively high because the catalysts contain relatively large amounts of bismuth and molybdenum, which are expensive. Even Furthermore, if the usual types of catalysts that are effective for the formation of acrylonitrile used with high selective conversion of propylene to acrylonitrile - and among such Conditions are used so that the reaction proceeds with a high conversion of propylene, shows the great majority of the usual types of catalyst a relatively small one selective conversion of propylene to acrylonitrile.

The above-mentioned selective conversion of propylene to acrylonitrile is hereinafter referred to as "percent selectivity to acrylonitrile".

In view of the above disadvantages, it is obvious that the production of acrylonitrile in high yield of 80% or more using common ~ catalyst types is very difficult.

The invention has the task of a new type of catalyst to make available the conversion of propylene to acrylonitrile at a proportionate rate low reaction temperature during a relatively short reaction time and with a) high yield of acrylonitrile of about 80X or more, b) high conversion of Propylene and c) allows with high selectivity to acrylonitrile. It was also sought that the above-mentioned with the new type of catalyst Targets without the use of bismuth, which is very expensive as a catalyst component, can be achieved. But even if the new type of catalyst should contain bismuth, the requirement was made that the catalyst in the ratio to molybdenum contains a proportion of bismuth that is less than the amount of bismuth that is in all other common types of catalyst is included.

The invention accordingly provides a method for catalytic Manufacture of acrylonitrile from propylene, ammonia and oxygen at a relatively low cost low reaction temperature and with a relatively high reaction rate in the presence of a catalyst that does not contain any bismuth or only very small amounts of bismuth contains, while achieving a) a high yield of acrylonitrile, b) a high one Conversion of propylene and c) a high selectivity to acrylonitrile.

It has been found that the objects set by the invention can be solved if a new type of catalyst is used, the one from Basic catalytic components and oxides of molybdenum, cobalt and iron contains a small amount of an additional component consisting of at least one composed of oxides of phosphorus, arsenic, antimony and bismuth, the atomic ratio being of the elements mentioned above lies in a very specific range. The invention is based on this finding.

The method according to the invention for the production of acrylonitrile is characterized in that a starting mixture, the propylene, ammonia and contains molecular oxygen, in the gas phase in contact with a catalyst brings that from a mixture of oxides of the empirical formula MoaCobFecXdOe consists, in which X contains at least one atom of an element - from the phosphorus, arsenic, The group consisting of antimony and bismuth is, a, b, c and d the respective number of atoms ~ of the elements, the ratio a: b.c: d in the range from 12: 4 to 9: 1 to 5: 0.01 to 0.07, and e is the number of oxygen atoms which the corresponds to the average value of the elements, with the ratio of a: e ranges from 12: 19.5 to 12: 52.7.

The invention is novel through the use of the above Catalyst characterized, which has the following advantages: 1) Also in use at a temperature of 3800C or below, which is far below the temperature, in the usual process for the catalytic conversion of propylene into acrylonitrile be carried out on an industrial scale, the catalyst has a sufficiently high catalytic Activity and carries out the conversion reaction within a contact time of about 2 seconds or less to complete.

2) The heat required to complete the conversion reaction is accordingly lower than the heat requirement in the conventional process, and the catalyst can be used for a longer time than with the usual methods the case is.

3) The yield of acrylonitrile per unit amount of the catalyst is higher than the usual method.

4) The conversion of propylene and the selectivity to acrylonitrile are higher than with the usual procedures.

Accordingly, in the method according to the invention, the amount of by-products is lower from side reactions and the yield of acrylonitrile that is about 80%, higher than the usual method.

5) The cost of the new catalyst is lower than that of the usual one Catalysts because the new catalyst has no bismuth or only very small amounts of bismuth contains.

6) The use of the new type of catalyst thus enables production of acrylonitrile with a remarkably high degree of efficiency and high economy.

In the new catalyst according to the invention the atomic ratio a: b: c: d range from 12: 4 to 9: 1 to 5: 0.01 to 0.07. When the amounts of molybdenum, Cobalt and iron are outside the above range, the Selectivity to acrylonitrile and the propylene conversion lower. In particular, the Selectivity to acrylonitrile much worse. If the catalyst is phosphorus, Contains arsenic, antimony or bismuth in an atomic number whose upper limit is above that above-mentioned upper limit of 0.07 and the catalytic reaction at a relatively low temperature of about 3800C or less in one relatively short contact times of about 2 seconds or less becomes, both the selectivity to acrylonitrile and the conversion of propylene lower. It thus becomes difficult to produce acrylonitrile in a high yield of about 80%. When the atomic number for phosphorus, arsenic, antimony or bismuth in the catalyst is below is the prescribed lower limit of 0.01, the catalytic activity of the catalyst is insufficiently low and the yield of acrylonitrile becomes undesirable low.

In the new type of catalyst according to the invention are the elements of Catalyst components in the form of oxides. Some of the oxides can form a complex form.

Several of the elements mentioned together with oxygen can form a Form connection.

The types of processes for preparing the catalyst according to Invention is not subject to any restriction. In general, the catalyst can be prepared by making an aqueous mixture containing a molybdenum Compound, a cobalt-containing compound, an iron-containing compound and at least one compound selected from the group consisting of phosphorus-containing, arsenic-containing, Contains antimony-containing and bismuth-containing compounds, the aqueous mixture is converted into the dried solid state and the dried solid mixture calcined at a temperature of at least 5500C.

The compounds that contain the elements of the catalyst components, can be in the form of oxides, hydroxides, salts or acids. To be favoured Salts that are thermally decomposable. Suitable compounds containing molybdenum molybdic acid, ammonium molybdate, molybdenum trioxide, phosphomolybdic acid, ammonium phosphorus molybdate and molybdenum sulfide.

Compounds containing cobalt are cobalt carbonate, cobalt nitrate, Cobalt (II) oxide, cobalt (III) oxide, cobalt chloride, tricobalt tetroxide, cobalt (II) hydroxide, Cobalt (i-ii) hydroxide and cobalt sulfide are suitable.

Suitable iron-containing compounds are iron (II) nitrate, iron (III) nitrate, Iron (II) oxide, iron (III) oxide, iron (II) chloride, iron (III) chloride, iron (II) hydroxide, Iron (III) hydroxide, iron (III) phosphate, iron sulfides, iron (II) sulfate and iron (III) sulfate.

Suitable compounds containing phosphorus are: pyrophosphoric acid, Metaphosphoric acid, phosphoric acid, ammonium phosphorus molybdate, phosphorus molybdic acid, Ammonium phosphate, phosphorus trichloride, diphosphorus tetroxide and diphosphorus pentoxide.

Compounds containing arsenic are arsenic chloride, arsenic (III) anhydride and arsenic pentoxide suitable.

Suitable compounds containing antimony are antimony trichloride, Antimony pentachloride, diantimony trioxide, diantimony pentoxide, antimony oxychloride, antimony hydroxide, Antimony pentoxide, antimony trisulfide and antimony pentasulfide.

The bismuth-containing compound can be selected from the bismuth chloride, Bismuth nitrate, bismuth oxide, bismuth oxychloride, bismuth hydroxide and bismuth subnitrate Group can be selected.

In the preparation of the catalyst, the conversion of the aqueous Mixture can be made into a solid mixture by evaporation. It is also possible, subjecting the aqueous mixture to a precipitation treatment in which all compounds which contain the elements of the catalyst components, are precipitated. The precipitation is separated from the mixture by filtration or centrifugation and then dried.

The solid mixture prepared in this way is at a temperature of at least 5500C for a time such that the solid mixture is converted into an activated catalyst. The calcination temperature is preferably in the range from 550 to 7000C. When calcined at temperature below 5500C the selectivity to acrylonitrile is worsened. Calcination temperatures above 7000C lead to a decrease in the conversion of propylene.

The above-described catalyst according to the invention can be made from consist of the catalytic component alone. However, to the mechanical strength To improve the catalyst, the catalytic component is preferably on applied to a carrier. As a carrier can be any conventional carrier materials be used. However, a carrier made of at least one material is preferred from that of silica, alumina, silica-alumina, and silicates existing group. The size and shape of the catalyst are subject no restriction. For example, the catalyst according to the invention can sifted to a desired size and into the desired shape according to the purpose and by depends on the conditions under which the catalyst is to be used, e.g. in the form of powder, granules, granules, pellets or tablets with the desired Strength can be brought. It should also be noted that the shape of the catalyst does not result in any change in the catalytic activity of the catalyst.

To illustrate, the following is a method of manufacture of a catalyst according to the invention, which consists of molybdenum, cobalt, iron, phosphorus and oxygen. A certain amount of ammonium molybdate will be dissolved in a certain amount of water heated to a temperature of 50 to 900C. A predetermined amount of phosphoric acid is added dropwise to this solution under constant Stir added. Furthermore, an aqueous solution containing predetermined amounts of cobalt nitrate and containing ferric nitrate, added dropwise to the solution. A slurry is received. The slurry is evaporated to give a dried solid Mixture is obtained. The solid mixture is at a temperature of at least 5500C, preferably calcined from 550 to 7000C. To make a catalyst in which the catalyst component is applied to a carrier, the carrier becomes preferably mixed with the aforesaid slurry. However, it is to note that the preparation of the catalyst according to the invention does not the above-described bene procedure is limited.

In the process of the invention there is that to be used in the reaction Starting mixture of propylene, ammonia and molecular oxygen. This starting mixture can be prepared by placing a propylene-containing material in the gas phase mixed with ammonia and a gas containing molecular oxygen. as Molecular oxygen-containing gas can be used technically pure oxygen gas will. However, the gas containing the molecular oxygen does not have to be special have high oxygen concentration. Accordingly, molecular oxygen can be used as a gas contains air, which is economically advantageous, can be used.

Containing propylene used for the process according to the invention Material need not be in the form of high purity propylene. Preferably however, if a material is used that is free of certain types of compounds, e.g. n-butylene and acetylene, which under the catalytic conversion conditions of propylene are reactive.

In a preferred embodiment of the invention, it is in the starting mixture for the reaction the molar ratio of propylene to oxygen in the range of 1: 1 up to 1: 3, preferably 1: 1.2 to 1: 2 and the molar ratio of propylene to ammonia in the range from 1: 0.5 to 1: 2.0, preferably 1: 0.8 to 1: 1.2.

The starting mixture for the reaction can be an inert diluent gas, that does not affect the conversion of propylene to acrylonitrile, e.g. nitrogen, Contains carbon dioxide and water vapor. In particular, water vapor not only increases the selectivity to the desired acrylonitrile, but also the durability the catalytic activity of the catalyst.

Preferably the molar ratio of the diluent gas is to Propylene in the starting mixture 0.5 or more.

The contact of the starting mixture of the reaction with the catalyst can take place under normal pressure, slightly increased pressure or slightly reduced pressure, however, it is expedient to work at normal pressure.

The reaction in the method according to the invention is increased Temperature, which is preferably in the range from 300 to 4700C, carried out, wherein a temperature of 330 to 450 ° C. is particularly preferred. In particular, it can Process according to the invention at a relatively low temperature in the Range from 350 to 4000C, especially at around 3800C because the Catalysts according to the invention are extremely active at this temperature.

With regard to the contact time of the starting mixture with the catalyst there is no limit as long as the desired oxidation occurs within the contact time is accomplished. The reaction according to the invention can be carried to completion be by adding the starting mixture for 0.2 to 10 seconds, preferably 0.5 to 5 seconds is kept in contact with the catalyst under normal pressure. However, it is to note that the catalyst according to the invention enables the reaction within a contact time between 1 and 3 seconds, in particular in a contact time about 2 seconds to complete.

The catalyst according to the invention can be used as a fluidized bed, agitated Bed or fixed bed can be used.

In particular when using the fixed bed for the method according to According to the invention, steam is preferably added to the starting mixture for the reaction added because of maintaining the catalytic activity of the catalyst in the fixed bed by adding steam is favored.

The acrylonitrile formed in the process according to the invention can by any conventional method, such as those described in U.S. Patents 3,424,781 and 3,688,002 methods described, are isolated from the reaction mixture.

The use of the method according to the invention enables manufacture of acrylonitrile in high yield and with high selectivity to acrylonitrile, while the formation of undesired by-products is limited by side reactions. Further it should be noted that in the process according to the invention, the increase in conversion propylene does not affect the selectivity to acrylonitrile. This is one the technical advantages of the method according to the invention.

In the following examples, the conversion of propylene in percent, the selectivity to acrylonitrile in percent and the yield of acrylonitrile with the help calculated from the following equations: Conversion of propylene in% = ### x100 selectivity to acyl nitrile in% = ### X1 to X2 Yield of acrylonitrile in% = Y x 100 X1 Herein X1 denotes the amount of propylene contained in the starting mixture before the start of the reaction in moles, X2 is the remainder contained in the reaction mixture after the reaction has ended Amount of propylene in moles and Y the amount of acrylonitrile obtained in moles.

Example 1 A mixture of the catalyst components in the form of an aqueous Slurry was made as follows: 170.3 ammonium molybdate gNH4) 6.Mo7024.4 H20 / were dissolved with stirring in 250 ml of water that had previously been heated to 80.degree was. 0.236 g of phosphoric acid (H3PO4) were then added dropwise to this solution. Then a second solution, which was obtained by dissolving 187.2 g of cobalt nitrate [CO (NO3) 2.6H2O] and 65.0 g of iron (III) -ni - entered LFe (N03) 3.9 H2O] in 200 ml of water at 800C was added dropwise to the solution.

An aqueous slurry was obtained.

The slurry was brought to a temperature with stirring. from 1200C heated until a dry solid mixture of the above materials is formed would have.

The dry solid mixture was formed into tablets that had a diameter of of 5 mm and a thickness of 5 mm. The tablets were made at a speed heated from 100 ° C / hour to a temperature of - 6000C and at this temperature Calcined in a calcining furnace for 5 hours while air was bubbled through.

The catalyst obtained had an atomic ratio of Mo: Co: Fe: P from 12: 8: 2: 0.03.

A reaction column was formed by adding 10 ml of the described in US Pat Way established. n catalyst in a U-shaped glass tube with an inner diameter of 8 ~ mm were filled. The reactor was heated to a temperature of 380 ° C and held at this temperature. A starting mixture that can be obtained by mixing Propylene, ammonia, air and water vapor in a molar ratio of 1.0: 1.0: 11.0: 2.0 in the gas phase had been produced, was at ~ a rate of 300 ml / Minute passed through the reactor. The starting mixture was 2.0 seconds with the Catalyst in contact held.

Examples 2 and 3 The experiment described in Example 1 was repeated, however, the atomic ratio of Mo, Co, Fe and P in the catalyst is 12: 8: 2: 0.05 in the case of Example 2 and 12: 8: 2: 0.07 in the case of Example 3.

Example 4 The experiment described in Example 1 was repeated, however, the atomic ratio of Mo, Co, Fe and P in the formed catalyst is 12: 8: 2.5: 0.03 and the starting mixture was at a temperature of 4000C with the catalyst was brought into contact.

Comparative Example 1 The experiment described in Example 1 was repeated, but with no phosphoric acid in the preparation of the catalyst was used.

Comparative Example 2 The experiment described in Example 1 was carried out repeated except that the atomic ratio of Mo, Co, Fe and P in the obtained catalyst 12: 8: 2: 0.5, i.e. the proportion of phosphorus in the prepared catalyst was above 0.07, i.e. above the upper limit of the phosphorus content according to the invention.

The results of those described in Examples and Comparative Examples Experiments are given in Table 1 below.

Table 1 Example atomic ratio of the elements Contact React Conversion Selectivity Yield No. in the catalyst component time, tional from pro to Acylni- an Acryl-Mo Co Fe P sec. Temp., Pylene, tril,% nitrile,% ° C% 1 12 8 2 0.03 2.0 380 96.6 83.1 80.3 2 12 8 2 0.05 2.0 380 96.5 85.5 82.5 3 12 8 2 0.07 2.0 380 93.0 86.0 80.0 4 12 8 2.5 0.03 2.0 380 97.4 84.7 82.5 Comparative Example No.

1 12 8 2 - 2.0 380 90.4 80.3 72.6 2 12 8 2 0.5 2.0 380 85.1 80.9 68.8 Example 5 In 250 ml of water which was heated to 80.degree 170.1 g ammonium molybdate /TNH4)6.Mo7024.4 H20 / dissolved.

Then 0.468 g of antimony trioxide (Sb2O3) were in the solution with stirring suspended. This was followed by a second solution that was made by dissolving 186.9 g cobalt nitrate /5o(N03)6.6 H207 and 64.9 g iron (III) nitrate / Fe(N03)3.9 in in 200 ml of hot water of 800C had been prepared, mixed with the suspension, whereby a mixture was obtained in the form of an aqueous slurry.

The suspension was evaporated with stirring at a temperature of 1200C, whereby a dry solid mixture was formed. This mixture became tablets formed with a diameter of 5 mm and a thickness of 5 mm. The tablets were heated to 6000C at a rate of 1000C / hour and at this temperature Calcined for 5 hours to obtain a catalyst. In this catalyst the atomic ratio of Mo: Co: Fe: Sb was 12: 8: 2: 0.04.

The same reaction as in Example 1 was carried out using 10 cm3 of the catalyst prepared in the manner described carried out. Of the Propylene conversion was 94.8%, the selectivity to acrylonitrile was 84.5% and the yield of acrylonitrile 80.1%.

Example 6 169.8 g of ammonium molybdate were dissolved in 250 ml of water which had a temperature of 800C. A second solution was made by dissolving of 1.55 g of bismuth nitrate / Bi(N03)3.5H207 in 5 ml of 15% nitric acid. A third solution was made by dissolving 186.6 g of cobalt nitrate go (N03) 3-6H20 / and 64.8 g of iron (III) nitrate / Fe(N03) 3.9 H207 in 200 ml of hot water at 800C manufactured. The second solution and the third Solution were the first solution was added dropwise with stirring, a mixture in the form of an aqueous Slurry was formed.

The slurry was evaporated at 120 ° C. with stirring, whereby a dry solid mixture was obtained. This mixture was molded into tablets, which had a diameter of 5 mm and a thickness of 5 mm. The tablets were heated to 6000 ° C. at a rate of -100 ° C./hour and at this temperature Calcined for 5 hours to obtain a catalyst in which the atomic ratio of Mo: Co: Fe: Bi was 2: 8: 2: 0.04. The reaction described in Example 1 was using 10 ml of the catalyst prepared in the manner described carried out.

Example 7 The experiment described in Example 6 was repeated, however, the atomic ratio of Mo, Co, Fe and Bi in the catalyst 12: 8: 2: 0.07 fraud.

Example 8 The experiment described in Example 6 was repeated, however, the catalytic reaction is carried out at a temperature of 4000C became.

Example 9 The same experiment as in Example 6 was repeated, -However, the calcination temperature during the preparation of the catalyst is 6500C fraud.

Comparative Example 3 The experiment described in Example 6 was repeated, but the atomic ratio of Mo, Co, Fe and Bi was 12: 8: 2: 1, i.e. the proportion of bismuth was outside the range prescribed according to the invention of the bismuth portion.

Comparative Example 4 The experiment described in Comparative Example 3 was repeated, but the catalytic reaction at a temperature of 400C was carried out.

The results of those in the above Examples and Comparative Examples The experiments described are given in Table 2 below.

Table 1 Example atomic ratio of the elements Calcinie- Reaction- Conversion Selective Yield No. in the catalyst component tion temp., Temperature from Pro- vity to an Acryl-Mo Co Fe Bi ° C ° C pylene, acrylonitrile,%% nitrile,% 6 12 8 2 0.04 600 380 96.2 83.8 80.6 7 12 8 2 0.07 600 380 96.8 82.9 80.2 8 12 7 2.7 0.04 600 400 97.2 83.2 80.9 9 12 8 2 0.04 650 380 95.0 84.3 80.0 Comparative example No.

3 12 8 2 1 600 380 83.1 83.5 69.5 4 12 8 2 1 600 400 94.8 81.0 76.8 example 10 170.2 g of ammonium molybdate /TNH4)6Mo7024.4 H207 were dissolved in 250 ml of water, that had a temperature of 800C.

0.318 g of arsenic trioxide (As203) were dissolved in this solution. One second solution was made by dissolving 187.0 g of cobalt nitrate / Co(N03)2.6 H20 / and 64.9 g of iron (III) nitrate / Fe(N03)3.9 H207 in 200 ml of water, which has a temperature of 80 ° C. The second solution became the first solution dropwise was added to give a mixture in the form of an aqueous slurry.

This slurry was dried with stirring at 1200C, whereby a solid mixture was obtained. This mixture was formed into tablets which each had a diameter of 5 mm and a thickness of 5 mm. The tablets were heated at a rate of 1000C / hour to a temperature of 6000C and calcined at this temperature for 5 hours. A catalyst with an atomic ratio of Mo, Co, Fe and As of 12: 8: 2: 0.04 was obtained.

The same catalytic reaction as in Example 1 was carried out using carried out by 10 ml of the catalyst prepared in the manner described. In this reaction, a propylene conversion of 95.6%, a selectivity to acrylonitrile of 82.2% and a yield of 78.6% were achieved.

Example 11 A first aqueous solution was made by dissolving 170.2 g of ammonium molybdate /TNH4)6Mo7024.4 H207 in 250 ml of water that is brought to a temperature was heated from 800C, and subsequent dissolution of 0.16 g arsenic trioxide (As203) made in the resulting solution.

A second solution of 0.78 g bismuth nitrate / Bi(N03)3.5 H2O] in 2.5 ml of 15% nitric acid and a third solution made by dissolving 187.0 g Cobalt nitrate tCo (N03) 3.6 H20 / and 64.9 g iron (III) nitrate EFe (N03) 3.9 H2 in 200 ml of water having a temperature of 80 ° C. was prepared dropwise while stirring the first aqueous solution added, wherein a mixture in the form of a aqueous slurry was obtained.

The slurry was dried with stirring at 1200C, whereby a solid mixture was obtained. This mixture was formed into tablets, the one 5 mm in diameter and 5 mm in thickness. The tablets came with a Heated at a rate of 1000C / hour to a temperature of 6000C and 5 hours calcined at this temperature. A catalyst in which the atomic ratio of Mo: Co: Fe: Bi: As 12: 8: 2: 0.02: 0.02 was obtained.

Using 10 cm3 of this catalyst, that in example 1 carried out catalytic reaction described.

Example 12 The experiment described in Example 11 was repeated, however, 0.236 g of phosphoric acid (H3PO4) was used instead of arsenic trioxide became.

The results of the experiments described in Examples 11 and 12 are listed in Table 3.

Table 3 Example 11 12 Atomic ratio of the elements in the catalyst component Mo 12 12 Co 8 8 Fe 2 2 Bi 0.02 0.02 As 0.02 -P - 0.03 Propylene conversion,% 96.8 97.0 Selectivity to acrylonitrile,% 83.9 83.5 Yield of acrylonitrile,% 81.2 81.0

Claims (15)

P a t e n t a- n s p r ü c h e 1) Process for catalytic production of acrylonitrile, characterized in that one starting material, propylene, Contains ammonia and molecular oxygen in the glass phase at elevated temperature brings into contact with a catalyst consisting of a mixture of oxides. of the empirical formula MoaCobFecXdOe, in which X is at least an atom of an element from the. Phosphorus, arsenic1, antimony and bismuth existing Group is, a, b, c, d, and e means the respective number of atoms of the elements, where the ratio a: b: c: d is in the range from 12: 4 to 9: 1 to 5: 0.01 to 0.07, and e denotes the number of oxygen atoms, that of the average valence of the elements, the ratio of a: e in the range from 12: 39.5 to 12: 52.7. 2) Method according to claim 1, characterized in that m one the Reaction at a temperature from 3000 to 470 ° C, preferably from 3300 to 4500C performs. 3) Procedure according to. Claim 1 and 2, characterized in that the reaction at a temperature in the range of 3500 to 400 ° C, preferably at a temperature of about 380 ° C is carried out. 4) Method according to claim 1 to 3, characterized in that the contact time 0.2 to 10 seconds, preferably 0.5. to 5 seconds. 5) Method according to claim l to 4, characterized in that the Contact time is 1 to 3 seconds, preferably about 2 seconds. 6) Method according to claim 1 to 5, characterized in that the The starting mixture for the reaction is an inert one Contains diluent gas. 7) Method according to claim 1 to 6, characterized in that the The ratio of the diluent gas to propylene in the starting mixture is 0.5 or more. 8) Process according to claim 1 to 7, characterized in that one water vapor, nitrogen and / or carbon dioxide are used as the diluent gas. 9) Process according to claim 1 to 8, characterized in that one the molecular oxygen in the starting mixture in the form of pure oxygen gas or Air used. 10) Method according to claim 1 to 9, characterized in that the Propylene-containing material contained in the starting mixture free of n-butylene and is acetylene. 11) Method according to claim 1 to 10, characterized in that the molar ratio of propylene to oxygen in the starting mixture is in the range of 1: 1 to 3, preferably in the range from 1: 1.2 to 1: 2. 12) Method according to claim 1 to 11, characterized in that the molar ratio of propylene to ammonia in the starting mixture in the range ton 1: 0.5 to 1: 2.0, preferably in the range from 1: 0.8 to 1: 1.2. 13> The method according to claim 1 to 12, characterized in that one uses a catalyst based on silica, alumina, silica-alumina and / or a silicate is applied as a carrier. 14) Method according to claim 1 to 13, characterized in that the catalyst is used as a fixed bed or fluidized bed. 15) Method according to claim 1 to 14, characterized in that one uses a catalyst that is produced has been through Forming an aqueous mixture containing a molybdenum-containing compound, a Cobalt-containing compound, an iron-containing compound and at least a compound selected from the phosphorus-containing compounds, arsenic-containing Compounds, antimony-containing compounds and bismuth-containing compounds existing group, converting the aqueous mixture into a dry solid Mixing and calcining the dry solid mixture at a temperature of at least 5500C, preferably at a temperature in the range 5500 to 7000C.