Patent ID: 8585870

Claim:
A process for co-manufacture of acrylonitrile and hydrogen cyanide comprising (a) operating an acrylonitrile process and a hydrogen cyanide process in parallel in separate reactor systems to produce an acrylonitrile reactor product stream and a stream comprising hydrogen cyanide, respectively, wherein the hydrogen cyanide is produced from reaction of natural gas (methane), ammonia, and oxygen or from methane and ammonia; (b) in a single recovery/purification system, combining the stream comprising hydrogen cyanide and the acrylonitrile reactor product stream in an absorber column with water, to produce a combined product stream, having a ratio of acrylonitrile to hydrogen cyanide of about 9 to 1 or less; and (b) treating the combined product stream sequentially in a recovery column, a decanter having an aqueous layer and an organic layer, and a heads column, wherein pH is controlled by addition of an acid at pH of 7.0 or less in the absorber column and the recovery column, and at pH less than 4.5 in the decanter and heads column.