PROCESS FOR THE REMOVAL OF UNREACTED AMMONIA

摘要

Unreacted ammonia resulting from the reaction producing acrylonitrile by the so-called ammoxidation of propylene is removed by cooling the reaction product by direct contact with quenching water while adding an acid to remove or recover the unreacted ammonia in the form of a salt thereof. The cooling is effected stepwise in two or more stages, thereby to increase the concentration of the ammonium salt solution withdrawn out of the system at the first cooling stage, and considerably reduce the cost of the recovery of the ammonium salt.