SU793640A1 - Method of preparation substrate for ammonia synthesis catalyst - Google Patents

Description

Aluminum oxychloride is obtained by peptizing freshly hydrochloric aluminum hydroxide at 20 ° C to pH 4. To obtain a carrier of composition Pe 2 O 3 - 67% by weight, AO 3 - 29% by weight and B20 3 to 4% by weight 70 g ferrigel combined with 30 g of aluminum oxychloride. Then boric acid is added to the mixture in an amount of 15 wt.% With respect to the alumina introduced. The resulting colloidal system is sent to a molding column, in which spherical granules are obtained by coagulating in a droplet in a layer of kerosene and 15% ammonia water. The formed granules are dried in air for 2 days. at room temperature, then at 120 ° C for 12 hours and at 220 ° C for 2 hours. The carrier is then calcined at 900, 1100 or 1300 ° C and after slowly cooling to room temperature, it is discharged.

Example 2. 60 g of ferrigel are combined with 40 g of aluminum oxychloride. Then boric acid is added to the mixture in an amount of 15 wt.% With respect to the alumina introduced. The resulting colloidal system is molded. The formed granules are dried as in Example 1. The carrier is then calcined at 1100 ° C and, after slowly cooling to room temperature, is discharged. Composition of the carrier: RegOz - 57%, ALOZ - 39%, VOSOZ - 4%.

Example 3. 80 g of ferrigel are combined with 20 g of aluminum oxychloride. Then boric acid is added to the mixture in an amount of 15 wt.% With respect to the alumina introduced. The resulting colloidal system is molded. The formed granules are air-dried as in Example 1. The carrier is then calcined at 1100 ° C and, after slowly cooling to room temperature, is discharged. The composition is tel: RegOz - 77%, - 19%, VgOz - 4%.

Example 4. The samples obtained in examples 2, 3 and the sample of example 1, calcined at 1100 ° C, are impregnated with a 10% aqueous solution of potassium nitrate and calcined at a temperature of 600 ° C until the salt is completely decomposed to potassium oxide. Impregnated carriers of different composition are tested for activity under the following conditions for ammonia synthesis: a volumetric rate of 30,000 h - N2: H2 ratio of 25:75 (06.%), temperature of 500 ° C, pressure of 300 atm.

The table shows some of the physicochemical characteristics of iron-aluminoborate carriers in examples 1-3, of the known aluminoborate carrier composition - 85 wt.%, B2Oz - 15 wt.% And

industrial catalyst for ammonia synthesis CA-1.

Thus, the proposed method makes it possible to obtain an iron-aluminoborate carrier, active in the process of ammonia synthesis, with mechanical strength when crushed on a lever press 1000-4500 kg / cm for spherical granules with a diameter of 1.5 mm. Abrasion when the number of fluidization equal to 2 does not exceed 1% per month. This support is suitable for the preparation of a catalyst for ammonia synthesis in a fluidized bed.

The implementation of ammonia synthesis in a fluidized bed of catalyst allows for significant;

It is necessary to reduce the size of the catalyst granules and to avoid the intradiffusion braking of the process, which leads to a decrease in the catalyst loading in the contact apparatus and an increase in productivity by approximately 1.5 times.

Claims (2)

Invention Formula A method of preparing a carrier for an ammonia synthesis catalyst by coagulating a mixture of aluminum oxychloride and boric acid, followed by molding 5 and heat treatment, characterized in that, in order to obtain a carrier with enhanced mechanical strength and active in the ammonia synthesis reaction, the coagulation is carried out in the presence of a ferrigel 5 in the amount of 57-77 May. % and heat treatment is carried out at a temperature of 900-1300 ° C. 6 Sources of information taken into account during the examination 1. USSR author's certificate No. 207217, cl. B 01 J 21/02, 1967. 2. USSR author's certificate No. 474505, cl. C 01 F 7/02, 1976 (prototype).