Patent ID: 6442969
Filing Date: 2002-09-03
Classification: B01D,C01B,F25J,Y02C,Y02P,Y10S

Abstract:
A process for separating a fraction of acid gases comprising at least one of carbon dioxide and hydrogen sulfide from a gaseous mixture comprising at least one gas lighter than said acid gases, said process comprising the following stages:(a) precooling said gaseous mixture (1) at least once; (b) passing resultant precooled gaseous mixture obtained from stage (a) upwardly into an approximately vertical heat exchange zone (ER) wherein said gaseous mixture is indirectly heat exchanged to provide a downward liquid reflux, thereby contacting and rectifying the upwardly moving precooled gaseous mixture; (c) collecting at the top of the vertical exchange zone, a gaseous fraction (8) depleted in acid gases and enriched in light gas; and (d) collecting at the bottom of the exchange zone a liquid fraction (4) enriched in acid gas components; at least partly expanding and evaporating the liquid fraction collected at the end of stage (d) to provide, at least partially, refrigeration required during stage (b), and also to provide a mixture of expanded gaseous fraction and an acid-gas containing liquid fraction; and separating the expanded gaseous fraction(s) (10, 12) from the acid gas-rich liquid fraction and recycling the separated expanded gaseous fractions (10, 12) to stage (a).