PEP Review 90-1-3
Acetonitrile Recovery in Acrylonitrile Manufacture
Published: June 1991
The manufacture of acrylonitrile by the ammoxidation of propylene is currently the exclusive source of the commercial production of acetonitrile-where it is formed as a by-product in the reactor at levels that typically are 2 to 3 wt%, with respect to acrylonitrile. Most acrylonitrile plants do not include facilities to recover acetonitrile, and the over-all extent of recovery in the free world is below 1 wt% of the corresponding acrylonitrile production, owing to the limited outlets for this by-product. Unused crude acetonitrile is disposed of as an effluent, usually by incineration.
In this review, we evaluate the economics of acetonitrile recovery by a process that entails a combination of azeotropic distillation and chemical treatment. The basic concept for the process is derived from various patents-in particular, those assigned to Standard Oil of Ohio or Sohio (now BP America) and E.I. du Pont de Nemours & Company.