Process for cleaning or purifying aqueous N-methylmorpholine-N-oxide solutions

US5178764A · kind A · utility

Assignee

• LENZING AKTIENGESELLSCHAFT · AT

Inventors

• Stefan Astegger · Vöcklabruck, AT
• Heinrich Firgo · Vöcklabruck, AT
• Bernd Wolschner · Vöcklabruck, AT
• Johann Manner · Vöcklabruck, AT
• Karin Weinzierl · Vöcklabruck, AT
• Stefan Zikeli · Regau, AT
• Dieter Eichinger · Vöcklabruck, AT

Key dates

• Filing date: Nov 22, 1991
• Grant date: Jan 12, 1993
• Expiry date: Nov 22, 2011

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P70/62
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

An aqueous N-methylmorpholine-N-oxide solution which was used as a spinning bath in the production of cellulosic products is regenerated by contacting it with active coal, silicon dioxide or alumina adsorbent and filtering, thereby reducing turbidity, eliminating nitrosoamine, decolorizing the solution and removing transition metals like iron therefrom.