The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 02, 2010
Filed:
Oct. 07, 2002
Fred Korpel, Roosendaal, NL;
Gerrit Jan Boerman, Deventer, NL;
Roger Keranen Rains, Richfield, OH (US);
Fred Korpel, Roosendaal, NL;
Gerrit Jan Boerman, Deventer, NL;
Roger Keranen Rains, Richfield, OH (US);
Flexsys B.V., Deventer, NL;
Abstract
The present invention relates to a process for purifying a recycle base solution waste stream of a composition comprising a quaternary ammonium hydroxide comprising the steps of (a) providing an electrolysis cell which comprises an anolyte compartment containing an anode, a catholyte compartment containing a cathode, and a cation-selective membrane separating the anolyte and catholyte compartments, (b) charging the recycle base solution waste stream comprising the quaternary ammonium hydroxide to be purified to the anolyte compartment and charging water, optionally containing a quaternary ammonium hydroxide, to the catholyte compartment, (c) passing a current through the electrolysis cell to produce a purified aqueous quaternary ammonium hydroxide solution in the catholyte compartment, (d) recovering the purified aqueous quaternary ammonium hydroxide solution from the catholyte compartment, (e) washing the anolyte compartment with a suitable solvent, and (f) repeating steps (b)-(e). The process is particularly suitable for improving the purity of an aqueous solution comprising tetramethyl ammonium hydroxide, which was used in the production of 4-aminodiphenylamine for a number of reaction cycles.