SU692544A3 - Catalyst for the preparation of acrylonitrile - Google Patents

Description

(54) CATALYST FOR OBTAINING ACRYLONITRYL

one

The invention relates to the production of catalysts for the preparation of unsaturated nitriles from olefins by ammonolysis and the vapor phase of propylene or isobutene, in particular catalysts for the preparation of acrxtonitrile.

A known catalyst for the oxidative ammonolysis of olefins, whose composition corresponds to the empirical formula

 ,, (Mc} rr, (Ad) .Os

where A is a metal of the I A group; a 1-10; in 1-10;

from 0.01-5 ;,

d 0.01-5; m, n 1;

e - depends on the degree of oxidation of the oxide and the number of other elements 1.

The specified catalyst has a lack of active activity of propypene, 73% of which is reversed into acrylonitrile.

Closest to the invention is a catalyst for the preparation of unsaturated

nitriles, in particular acrylonitrile; empirical

j ba / jbWbCiieOe where a l-lO;

b 1-10;

in 0.01-5; g 0.01-5; e 4-65 2}.

The known catalyst has an insufficiently high activity -% conversion of propylene to acryloescryl is 73.4.

The aim of the invention is to improve act 1: catalyst properties.

This goal is achieved using a catalyst containing antimony, tin, copper, tungsten, oxygen and, in addition, zirconium, whose composition corresponds to the empirical formula

$ bj $ 7 Cup, 25-o, 375 0.015 Oio, 3-yl The proposed catalyst allows you to convert propylene to acrylonitrile by 77.489%.

Claims (2)

The catalyst can be made differently by water, for example, by thoroughly using oxide, separate precipitation or coaxialization of salts of soluble compounds consisting of components, or thermally (separately or jointly) decomposition of compounds that are converted into oxides when heated, or combined use the above techniques. In any method of manufacture, the catalyst is subjected to heat treatment at a temperature of 500-1000 ° C, preferably 700-900 ° C, carried out in an oxygen-rich atmosphere, for example, in air. The catalyst can be obtained by dispersing antimony trioxide in an aqueous solution of nitric acid, by introducing metallic powdered tin into the resulting suspension of antimony trioxide with stirring and heating to convert tin: to tin oxide. Residual nitric acid; removed by several successive operations: decantation, siphonising and washing with cold and hot water; copper 6 is introduced into the form of divalent copper nitrate, tungsten and zirconium in the form of the corresponding oxides. This, WOs and ZrOj, introduced into the aqueous suspension of antimony and tin oxides. Copper is precipitated with ammonia in the form of copper hydroxide. The precipitate after decanting and washing with water is filtered, dried and molded, for example, by tabletting. Then, heat treatment is performed in the air stream. Some of the ingredients can be added to the composition after drying and firing. In the manufacture of a catalyst, the introduction of vodfrarl can be carried out in the form of "ammonium aungstate, dissolved in Mineme; an alcalum amount of water, in the mixture obtained after the last filtration operation containing antimony, tin, copper and zirconium. The resulting mixture is dried and molded as indicated. During the ammo-oxidation of propylene, oxygen, amlshak and propylene are mixed with paraffin hydrocarbons, including those present in propylene. Air is usually used as a source of fuel. The molar ratio of oxygen and propyl. on, ammonia and propylene can vary over a wide range. The molar ratio of oxygen to propylene is typically 0.5-3.0, preferably it exceeds 1. The molar ratio of ammonia and propylene is usually 0.7-3, preferably 0.9-1.5. . - The catalytic conversion reaction of propylene to acrylonitrile oOfenmo is carried out in the presence of water vapor or an inert solvent, the amount of which may be 5-40% by volume, usually 1025% by volume of the total reactants. The reaction temperature is 350-520 ° C, preferably 380 ° -500 ° C. The pressure can be above or below atmospheric, most often it is close to atmospheric. The duration of the contact can vary over a wide range, for example, from 0.5 to 10 seconds, either up to 6 seconds. The catalyst may be present in the form of tablets, granules or small particles selected for the type of reactor used in KotopoM and, depending on whether the catalyst is used, in a fixed or fluidized bed. The catalyst can be used in the form of mixtures or a substrate of the usual type, for example, silica. PRI me R 1. Ka; the analyzer is prepared in the following manner. 2000 g of an aqueous solution of nitric acid with 18.5 wt.% HNOZ is heated with stirring at 95.degree. 218.6 g of powdered antimony O1OISI are dispersed in this solution. Potassium is added to 59.4 g of powdered tin. The temperature is maintained at this 97-99 ° C. Suspension sustain; then for 15 min at boiling (without stopping stirring), and then it is cooled to 40 ° C. Stirring is stopped, after de, cantash the upper superficial liquid layer is removed by siphoning, the remaining kwsxny is washed with stirring for 15 minutes, first 4 liters of cold After decanting and siphoning, the splash liquid is again washed with 4 liters of water at 98-100 ° C. After cooling to 40 ° C, decantation and siphoning, the slurry that pops up over the porridge is suspended in 2.5 liters of water and heated to 60 ° C. Then, 43.5 g of copper nitrate Cu (MOZU2 g PZaO and 61.6 g of zirconium oxide ZrO2) are added. Ammonia is then added to a pH of 6.3-6.5. After cooling, decanting and siphoning a pop-up layer, the slurry is washed through with stirring, 4 liters of cold water for 10 minutes and filtered off. The slurry is then placed in a mixer with a double heating jacket Next, add 2.02 g of ammonium per-voltamate (NH4) 6W7024 6HjO, before the cooker is dissolved in 20 ml. water.Mixing all ingredients thoroughly is carried out by stirring with simultaneous evaporation of water.The resulting powder is dried by heating for 12 hours at 135 ° C. Tabet- IKH is formed from the catalyst after addition to 1% by weight, used as a lubricant of graphite. 51 The resulting product is subjected to heat treatment in a stream of air at 800 ° C. As a result, 60 g of catalyst are obtained in the form of cylinders 5 × 4 mm in size. Sb metal elements; Sn 2g. Cu; W is contained therein in the ratio 3: 1: 1 g 0.375: 0.015. The product is placed in a catalytic reactor, which is a glass U-shaped tube with an internal diameter of 10 mm. A tube of yogruzhatsya in a bath of molten nitrates, heated to 460 C, 18 l / h of gaseous mixture is passed through the catalyst following the loiaero composition,%:.,.: Propylene-6 Ammonia7 Air 70 Water 17, Under these conditions 77.4% of propylene is converted into acrylonitrile, 6.1% in cyanistvoda p6dnic acid, 0.8% in acrolein, 7.0% in I carbonic acid and 3.6% in carbon monoxide, 5.1% propylene remain unrefined, etc., 60 g of catalyst, wherein the metal elements are antimony: tin: zirconium: copper: tungsten is in an atomic ratio of 3: 1: 1: 0.25:: 0.015, the term treatment at 800 ° C is tested in the apparatus used in Example I, but at 470 ° C and the flow rate of the gas mixture at 18 l / h. The mixture has the following composition,%: Propylene7 Ammonia8 Air70 Water15 Under these conditions, 89% propylene njpeo6pa; it is acrylonitrile, 0.6% in acrolein, 5.9% / in hydrocyanic acid, 6,% in carbonic acid, 3.2% in carbon monoxide, 4.8% propylene did not react. PRI me R 3. 75 g of catalyst, in which the metallic elements antimony: tin:: silicon: copper: tungsten is moved in a 4 atomic ratio of 3: 1: 1: 0.375: 0.015, subjected to heat treatment at 820 ° C , used in a catalytic reactor with an internal diameter of 14 mm, with a flow rate of the gas mixture of 21.6 l / h. The mixture has the following molar composition,%: Propylene6.5: Ammonia7.5; Air68.0 Water18.0 77.8% of propylene is converted to acrylo-nitrile, 1.2% to acrolein, 5.8% to cyanide; dehydroic acid, 7.9% to carbonic acid, 3.2%; to carbon monoxide, 4 , 1% of propylene is not: oreagyrova and. EXAMPLE 4: 75 g of the catalyst of example 3, but in the form of grains 35 mm in size, are tested in an apparatus similar to that described in example 3. The test is conducted fip 00 C with the flow rate of the gas mixture (with the same molecular composition as in example 3) 21.6 l / h. Under these conditions, 80.7%. propylene is converted to acrylo-nitrile, 0.5% to acrolein, 5.7% to cyanophosphoric acid: parent acid, 7.3% to carbon dioxide 3.2%: to monoclime acid, only 2.6% rrponmieiHa is not gfororephoza and. Claims of the invention: Catalyst for the obtained scattering compound, comprising suma, tin, copper, tungsten and oxygen, characterized in that, in order to increase the activity of the catalyst, it additionally contains zirconium, and the composition of the catalyst corresponds to the formula OD5-H375%, W 50.0, 3-10Д Sources of information received in BHHMaimer during examination 1. For France No. 2265732, cl. C 07 C 121/30,. 1975. 2. For France N 2265730, cl. From 07 to i 20/14, publ. 1975 (prototnp).