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:
Jun. 02, 1992
Filed:
Mar. 27, 1991
Stephan Astegger, Vocklabruck, AT;
Dieter Eichinger, Vocklabruck, AT;
Heinrich Firgo, Vocklabruck, AT;
Karin Weinzierl, Timelkam, AT;
Bernd Wolschner, Vocklabruck, AT;
Stefan Zikeli, Regau, AT;
Lenzing Aktiengesellschaft, Lenzing, AT;
Abstract
For the removal of water from dilute aqueous solution of NMMO, N-methylmorpholine or morpholine or mixtures thereof, the solution is subjected to reverse osmosis at a pressure in excess of the osmotic pressure and probably around 40 bar and a temperature of 25.degree. C. to 75.degree. C. to form a retentate containing the amines and a permeate which is practically free from the amines. The permeate can be used as process water while the retentate can be worked up to NMMO for reuse in the cellulose solubilization process.