Continuous purification of an off-gas composed of CO.sub.2 +HCl+COCl.sub.2

US5391363A · kind A · utility

Assignee

• BASF SE

Inventors

• Peter Ksoll · Dossenheim, DE
• Wolfgang Reuther · Neckargemünd, DE
• Peter Wittmer · Bischofswerda, DE

Key dates

• Filing date: Sep 10, 1992
• Grant date: Feb 21, 1995
• Expiry date: Sep 10, 2012

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/151
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A continuous process for purifying an off-gas which contains CO.sub.2 and HCl and COCl.sub.2. The process comprises passing the off-gas through a separator filled with N,N-dialkylformamide and HCl. This causes a reaction between the COCl.sub.2 and the N,N-dialkylformamide to give the Vilsmeier complex (adduct of COCl.sub.2 and dialkylformamide) and CO.sub.2. The CO.sub.2 leaving the separator contains small amounts of HCl.