GB814238A - Process for the preparation of acrylonitrile - Google Patents

Abstract

A process for the simultaneous production of acrylonitrile, monovinyl acetylene and acetaldehyde comprises introducing acetylene and HCN under a pressure of substantially 1-4 atmospheres absolute and at substantially 70-110 DEG C. into an aqueous solution of cuprous chloride containing hydrochloric acid, and ammonium chloride, sodium chloride, and/or potassium chloride, the quantity of HCN used being substantially 50-103 per cent of that quantity which would be converted into acrylonitrile when employing a large excess (more than 103 per cent) of HCN under corresponding reaction conditions. By operating in this manner, the acetaldehyde formed is not significantly converted into lactic acid nitrile by excess HCN, and may be recovered as such. The acetylene partial pressure is preferably 1-3.5 atmospheres, and the preferred temperature 80-90 DEG C. In a preferred embodiment, acetylene at 1.5 atmospheres pressure and 80 DEG C. is passed into an aqueous solution containing hydrochloric acid and 680 grams of CuCl per litre and 515 grams of KCl per litre, simultaneously introducing 3.8-7.8 grams of HCN per hour per litre of solution. The ratio of acrylonitrile to monovinyl acetylene produced may be increased by: (i) increasing the quantity of HCN (within the above limits); (ii) by decreasing the acetylene partial pressure; and/or (iii) by increasing, within the limits of 1 : 1 to 1 : 0.8, the mol. proportion of CuCl to the additional chloride. By-products obtained include lactic acid nitrile, cyanbutadiene, divinyl acetylene, higher acetylene polymers, and chloroprene.