System for the capture and release of acid gases

Abstract

In one aspect, the invention provides a method for the capture of at least one acid gas in a composition, the release of said gas from said composition, and the subsequent regeneration of said composition for re-use, said method comprising performing, in order, the steps of: (a) capturing the at least one acid gas by contacting said at least one gas with a capture composition comprising at least one salt of a carboxylic acid and at least one water-miscible non-aqueous solvent; (b) releasing said at least one acid gas by adding at least one protic solvent or agent to said composition; and (c) regenerating the capture composition by partial or complete removal of said added protic solvent or agent from said composition. Optionally, said capture composition comprising at least one salt of a carboxylic acid and at least one water-miscible non-aqueous solvent additionally comprises water or another protic solvent. In another aspect, the invention envisages a composition which additionally comprises at least one protic solvent or agent and release of the at least one acid gas is achieved solely by subjecting the composition to the application of heat or stripping with a stream of air. The method is typically applied to the capture and subsequent release of carbon dioxide, and offers a convenient and simple process which uses inexpensive consumables and offers significant advantages over the methods of the prior art.