SU475765A3 - Method for producing unsaturated aliphatic dinitriles - Google Patents

Description

pressure and temperature with a unit volume of catalyst is 0.001-20 seconds (preferably 0.001-10 seconds).

The composition of the gas stream in contact with the catalyst may vary widely; however, the possibility of forming explosive mixtures should be considered.

The molar ratio of oxygen-benzene is preferably 0.1 to 100, the molar ratio of ammonia to benzene is usually 1-20. The concentration of benzene in a gas note is not decisive. Typically, the concentration of benzene is maintained in the range of 0.1-20 vol. % The process can also be carried out in the presence of water banks. In this case, the molar ratio of water to benzene is preferably in the range of 1 to 10.

The ratio of dinitriles produced may vary depending on the reaction conditions. The selectivity of the dinitrile formation process is characterized by the number of moles of nitrile per 100 moles of benzene converted. By changing the reaction conditions, it is possible to increase its selectivity for 1.4 dicyclic butadiene-1, 3 and / or fumaric and maleic nitriles.

Example 1. A 4 ml catalyst was added to a 1 cm diameter tubular glass reactor obtained by calcining ammonium molybdate (NH4) 6 Mo7O24-41 20 in air at 500 ° C for 15 hours. A gaseous mixture containing (%): benzene 7, ammonia 14, air 73 and water jets (in volume percent) 6 — is passed over a layer of catalyst, aggrated to 450 ° C, at a rate of 7.2 l / h (under normal conditions x) within 4 hours. The gaseous products leaving the reactor are bubbled through chloroform cooled to 0 ° C. The benzene conversion is 10%.

The chloroform solution is evaporated to dryness to obtain a partially crystallizing oily residue, the weight of which is 0.9% of the loading of benzene. Chromatographic analysis shows that it contains mainly 1,4-dicyanobutadiene-1,3 as a mixture of cis-cis, cis-trans and trans-trans-isomers. The structure of the product is confirmed by its mass spectrum.

Example 2. In a solution of 88 g of ammonium molybdate in 150 ml of water, 150 g of alumina with a small specific surface (below 1) are immersed, then, after adding 2.3 g of phosphoric acid, it is scalded to dryness with stirring, and the resulting mixture is calcined in air at for 10 hours

The catalyst is filled with a 50 ml stainless steel U-shaped tubular reactor. It is immersed in a bath (bath) of molten nitrates heated to 440 ° C, and a gaseous mixture similar to that specified in the process is passed over the catalyst bed at a rate of 90 l / h under normal conditions.

Example 1. The benzene conversion is about 10%. The catalyst is washed in the column with xylene.

After concentration of the solution, the semi-residue is 2 wt. % of loaded benzene. Chromatographic analysis of the residue indicates the predominance of 1,4-dicyanobutadia-1,3 in it. Example 3. A 100 cm diameter catalyst containing a mixture of V2O5 (75 wt.%) And MoO3 (25 wt.%) On alumina (15 wt.%) With a granule diameter of 0.3-0 is loaded into a tubular glass PEJO actor with a diameter of 2 cm. 6 mm. The temperature in the catalyst bed is raised 15 to 450 ° C using an annular electric furnace. A gaseous stream of the following composition is passed over the catalyst bed (vol.%):

d benzene2

Oxygen11

Nitrogen82

Ammonia4

Water Noah

5 The gas flow rate (in terms of normal pressure and temperature conditions) is 36 l / h, the duration of the contact of the gas mixture with the catalyst is 0 ,.

After three hours of operation with the established mode, the chromatographic content (percentage) of CO and CO2 in the gaseous reaction products is determined. The heavy reaction products are trapped for 3 hours, using a gaseous note through the toluene cooled to (-80) ° C. The toluene solution is dried with magnesium sulfate, then chromatographed. The following substances are obtained (mg);

Fumaric acid nitrile12

0 Nitrile maleic acid50

Day, cis-cyanobutadiene38

Cis, trans-cyanobutadiene26

Trans, Trans-Dicyanobutadiene8. Conversion of benzene 0.35%. five

The selectivity of the formation of the reaction products (%):

Maleitic and fumaric acid nitriles39 0 Ditsmanobutadiene34 CO + C0211 Resin16.

The productivity of the reactor (g / h / kg 5 catalyst): maleic and fumaric acid nitriles 200, dicyanobutadienes 240.

The nitriles are separated as follows: the toluene solution is washed with a normal

aqueous solution of hydrochloric acid, then with water and dried over sodium sulfate, the solution is evaporated. The yellow residue is subjected to sublimation and a white solid is isolated, the mass spectrum of which is identical

the spectrum of a sample of 1,4-dicyaobutadiene-1,3.

Wash water is extracted with ether. After drying the ether solution over sodium sulfate and removing the ether, a yellow residue is obtained, the mass spectrum of which is the same as that of the fumaric nitrile sample (fuyaric acid nitrile).

PRI me R s 4-7. Under the conditions described in example 3, with different duration of contact of the gaseous stream with the catalyst, the results are given, which are listed in Table. one

Table I

 1,4-dicyano-butadiene-1,3. Nitriles fumaric and maleic acids.

Example 8. The method is similar to example 3, the duration of contact is 0.02 seconds, temperature 450 ° C.

The composition of the gas mixture (%):

Benzene2

Oxygen19

Ammonia4

Nitrogen -74

Water (steam) 1.

The catalyst VjOs on the substrate out, the diameter of the granules 0.3-0.6 mm. The content of UzOb in the catalyst is 15 wt. % The following results are obtained (%): benzene conversion 3.9; the output in terms of the loaded benzene dicyanobutadiene 0,4; the output of nitriles fumaric and maleic acids 2,2; Selectiveness of dicyanobutadiene formation 10, fumaric and maleic acid nitriles - 57.

 Example 12. A molybdenum oxide-based catalyst is obtained by impregnating alumina (alumina) with a granule diameter of 0.3-0.6 mm with an aqueous solution of ammonium molybdate. Then calcined impregnated alumina at 500 ° C. The resulting catalyst contains 15% MoO3 Catalyst prepared as follows: Vanadium pentoxide is dissolved in an aqueous solution of hydrochloric acid, alumina (alumina) is added to the resulting solution, then slowly sinarized with stirring: the solid residue is heated to 200 ° C and then kept 15 hour at 500 ° C.

Examples 9-P. Above the catalyst described in example 3, pass a gaseous stream containing benzene, air, ammonia, water vapor; flow rate of 14 l / h (in terms of normal conditions), the duration of contact is 0.025 sec. In various experiments, the percentage (in the gas mixture) of benzene and air is replaced, leaving the content of ammonia and water (4 and 1% by volume, respectively) unchanged. The results are given in table. 2

table 2

A drop of 100 mg of the catalyst thus obtained, heated to 450 ° C, passes a gaseous stream containing benzene, hydrogen chloride, nitrogen, ammonia, water in a volume ratio of 2: 19: 74: 4: 1, at a rate corresponding to a contact duration of 0.4 seconds

7

The following results are obtained (%): Benzene Conversion0.37

Output in terms of loaded

benzene:

1,4-dicyano-butadiene-1,30,11

fumaric and maleic nitriles 0.17

Selectivity of formation: 1,4-dicyano-butadiene-1,330

fumaric and maleic nitriles46.

Example 13. The process is conducted as described in example 12, using a catalyst based on tungsten oxide on a substrate of alumina (15 wt.%). Get the following results (%):

Example 17. The catalyst is prepared without a foul based on molybdenum, bismuth and phosphorus oxides as follows: 24.3 g of bismuth nitrate are dissolved in 30 ml of concentrated nitric acid and 7.9 g of molybdic acid and 1 g of phosphoric acid are added to the solution . The mixture is evaporated to dryness and calcined for 15 hours in air at 540 ° C. The resulting mass is crushed, sieved and granules of 0.3-0.6 mm in size are obtained.

Over 2 g of catalyst at which the mixture of gases of the same composition as in example 12 is passed; contact time 0.4 sec. The transformation ratio of benzene is 0.5%, the selectivity of the formation of fumaric and maleic nitriles is 29%, and dicyanbutadiene is 13%.

Examples 18-20. Three catalysts based on, respectively, iron oxides and antimony (catalyst A), oxides of tin and antimony (catalyst B), oxides of uranium and antimony (catalyst C) are prepared as follows.

Catalyst A. Carry out the co-precipitation of iron hydroxide and antimony by the action of ammonia on a solution of the corresponding

Benzene Conversion 0.14

Output in terms of loaded benzene:

dicyanobutadienes 0,01

fumaric + maleic

nitriles0.06

Education selectivity:

dicyanobutadiene7

fumaric and nitriles

maleic acid43.

Examples 14-16. The process is carried out, as described in example 3, by varying the weight of the respective ° °° 1000/0 in

wearing

CatalysisMOOOZ + VaOj

torus with a contact duration of 0.02 sec. The results are shown in Table. 3

Table 3

chlorides in aqueous solution of hydrochloric acid. After sucking the precipitate, it is washed with water, dried at 100 ° C, then calcined for 15 hours at 850 ° C. The catalyst is crushed, sieved and receive granules with a size of 0.3-0.6 mm. The atomic ratio of antimony: iron in the catalyst is 3.

Catalyst B. Tin and antimony are treated with dilute nitric acid, the precipitate is filtered off, washed with water, dried at 100 ° C and calcined for 15 hours at 700 ° C and 15 hours at 1000 ° C. Atomic concentration tin: antimony in the catalyst is 2.

Catalyst C. Impregnate alumina with a solution of uranyl nitrate and antimony chloride in aqueous hydrochloric acid. After evaporation to dryness, the residue is calcined with

stirring for 15 hours at 550 ° C in air.

The content of oxides in the catalyst is about

15 wt. %, atomic ratio bismuth: uranium

equals 2.

Carrying out the oxidative amination of benzene under the conditions of Example 17 with each of these catalysts, the results given in Table 2 are obtained. four

Table 4

Subject invention

Claims (3)

1. A process for the preparation of unsaturated aliphatic dinitriles, characterized in that, in order to simplify the process, a gas mixture consisting of benzene, ammonia and oxygen-containing gas vapors is contacted with an oxidative ammonolysis catalyst, for example with a catalyst based on randi and molybdenum oxides, at a temperature 200- 600 ° C with the selection of target products by known methods. 2. A method according to claim 1, wherein the process is carried out in the presence of water vapor. 3. Method according to paragraphs. 1 and 2, characterized in that the process is carried out with a contact time of the gas mixture with the catalyst of 0.001-20 seconds. Priority points 09/06/19 on p. 1; 11.05.71 pop 3