GB723935A - Improvements in or relating to a process for the manufacture of acrylonitrile - Google Patents

Abstract

A process of producing acrylonitrile by reacting acetylene and hydrogen cyanide at elevated temperature in the presence of a catalyst comprising an aqueous solution of cuprous chloride and one or more alkali metal halides, is characterized by the fact that the reaction is carried out with a catalyst solution having a concentration of total halides in excess of the eutectic composition and containing at least 1.03 moles of cuprous chloride per mol. of alkali metal halides. The catalyst solution may, for example, contain from 72 to 78 per cent by weight of total halides, and the amount of cuprous chloride may be up to 1.10 moles per mol. of alkali metal halides. Bismuth and/or arsenic compounds may replace part of the cuprous chloride in the catalyst composition as described in Specification 612,590. Such compositions form a clear solution on heating to above 45 DEG to 50 DEG C. In example (1) a catalyst solution comprises 0.8 mole of potassium chloride, 0.2 mole of sodium chloride, 1.075 moles of cuprous chloride and 3.2 moles of water, which is treated with hydrazine to remove cupric copper. Acetylene and hydrogen cyanide are passed in while heating to 80 DEG C., the hydrogen cyanide being used at 0.166 mole per hour per kilogram of catalyst solution, the acetylene at 6 to 8 times this rate. A table shows the proportion of acrylonitrile, acetaldehyde, hydrogen cyanide and vinyl-acetylene, in the exit gases. In example (2) the catalyst comprises 0.8 mole of potassium chloride, 0.2 mole of sodium chloride, 1.035 mole of cuprous chloride, 0.04 mole of bismuth chloride and 3.2 moles of water. Specification 591,945 also is referred to.