Patent ID: 6770189
Filing Date: 2004-08-03
Classification: B01D,C07C

Abstract:
A process for improving the purity of a composition comprising a quaternary ammonium hydroxide contained in a recycle stream obtained from the production of 4-aminodiphenylamine comprising the steps of(a) providing an electrolysis cell which comprises an anolyte compartment containing an anode, a catholyte compartment containing a cathode, and at least one intermediate compartment, said at least one intermediate compartment being separated from the anolyte and catholyte compartments by cation selective membranes, (b) charging water, optionally containing a supporting electrolyte, to the anolyte compartment, charging water, optionally containing a quaternary ammonium hydroxide, to the catholyte compartment, and charging the composition comprising said recycle stream to be purified to the intermediate compartment, (c) passing a current through the electrolysis cell to produce a purified aqueous quaternary ammonium hydroxide solution in the catholyte compartment, and (d) recovering the purified aqueous quaternary ammonium hydroxide solution from the catholyte compartment.