A PROCESS FOR CONTINUOUS HYDROGENATION OF ADIPONITRILE

摘要

A process for continuous hydrogenation of adiponitrile (DNA) to hexamethylene diamine (HMD) and optionally to amninocapronitrile (ACN) involving the catalytic hydrogenation of adiponitrile at relatively low temperature (e.g., 75 DEG C) and pressure (e.g., 500 psig) using a sponge cobalt catalyst (Raney3 Co) in a reaction medium that is substantially free of caustic. In such a process periodic addition of water controls the production of side reaction products and the periodic addition of ammonium hydroxide rejuvenates the catalyst. Hexamethylene diamine is an important intermediate for the synthesis of polyamides such as Nylon-6,6 and aminocapronitrile is a potential intermediate of Nylon-6.