SU497045A1 - The method of preparation of bismuth phosphate catalyst - Google Patents

Description

one

Know the method of preparing a bismuth phosphorus molybdenum catalyst for the synthesis of acrylonitrile by oxidative ammonolysis of propylene by applying an active mass to a borosilicate or silica gel carrier.

The proposed method is characterized in that, in order to increase the selectivity of the process and decrease the yield of by-products, it is envisaged to pretreat the carrier with nitric acid to remove alkali and alkaline earth metal impurities. As a result, the selectivity of the process increases to 78–82%, and the yield of carbon dioxide decreases to 6–8%, hydrocyanic acid to 4–5%, and acetonitrile to 4–5%.

Example. 100 ml of a fine-spherical carrier subjected to hydrothermal treatment at a temperature of 180 ° C, a pressure of 20 atm and a duration of 6 hours are treated with 200 ml of 15% nitric acid at room temperature for 1 hour. Then the acid is decanted and the carrier is washed with distilled water to the removed NO3 ions, then it is dried at 100-120 ° C and once saturated with an impregnating solution until the content of the active mass is 15 wt. %

The use of the catalyst prepared on this carrier gave the following indicators: total propylene conversion is 72%, the yield of acrylonitrile on the initial propylene is 54.5%, on the reacted propylene 80-

81%, carbon dioxide 6-8%, hydrocyanic acid 4-5%, acetonitrile 4-5%.

Subject invention

A method for preparing a bismuth phosphomolibdic catalyst for the synthesis of acrylonitrile by oxidative ammonolysis of propylene by applying an active mass to a carrier — borosilicate or silica gel, characterized in that, in order to increase the selectivity of the process and reduce the yield of by-products, the borosilicate or silica gel carrier is pretreated with nitric acid.