Process for removing acidic compounds from gaseous mixtures using a two liquid phase scrubbing solution

摘要

An improved process for removing carbon dioxide from a gaseous feed including carbon dioxide is described. The carbon dioxide is removed from a gaseous feed by contacting the feed in a contacting zone with a scrubbing solution comprising a sterically hindered amine and an alkali metal salt or alkali metal hydroxide, which at least partially absorbs the carbon dioxide. The scrubbing solution subsequently is desorbed and separated into a two-phase liquid system, an upper phase relatively rich in sterically hindered amine and having a relatively high ratio of alkali bicarbonate to alkali carbonate and a lower liquid phase having a relatively low ratio of alkali bicarbonate to alkali carbonate. The lower liquid phase is returned to the contacting zone at a location above that at which the upper liquid phase is returned to the contacting zone.