Removal of CO.sub.2 and/or H.sub.2 S from gases

US4997630A · kind A · utility

Assignee

• BASF SE

Inventors

• Eckhart Wagner · Ludwigshafen, DE
• Klaus Volkamer · Bischofswerda, DE
• Werner Hefner · Lampertheim, DE
• Ulrich Wagner · Bernburg, DE

Key dates

• Filing date: Mar 24, 1989
• Grant date: Mar 5, 1991
• Expiry date: Mar 24, 2009

Classification

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

Abstract

Gases containing CO.sub.2 and/or H.sub.2 S in a first absorption stage, at from 40.degree. to 100.degree. C., with an aqueous absorption liquid containing from 20 to 79% by weight of methyldiethanolamine, the gas obtained at the top of the first absorption stage is fed to a second absorption stage in which, it is treated at from 30.degree. to 90.degree. C. with an aqueous absorption liquid which contains from 20 to 79% by weight of methyldiethanolamine and has a lower content of CO.sub.2 and/or H.sub.2 S than the absorption liquid fed into the first absorption stage, the treated gas is taken off at the top of the second absorption stage, the aqueous absorption liquid obtained at the bottom of the second absorption stage and preladen with CO.sub.2 and/or H.sub.2 S is fed to the top of the first absorption stage, the aqueous absorption liquid obtained in the lower part of the first absorption stage and laden with CO.sub.2 and/or H.sub.2 S is let down in two or more flash stages in order to regenerate it, the final flash stage being operated under reduced pressure, a stream of absorption liquid obtained at the bottom of the final flash stage is recycled to the first absorption stage, …