Separation of carbon monoxide from nitrogen-contaminated gaseous mixtures also containing hydrogen and methane

摘要

Carbon monoxide is separated from a gaseous mixture containing hydrogen and methane and contaminated with nitrogen by scrubbing (8) carbon monoxide from a vapour portion (5) of the feed (1) by a liquid methane wash (36); stripping (15) dissolved hydrogen from the resultant CO-loaded liquid methane stream (13); fractionating (22) the resultant hydrogen-stripped CO-loaded liquid methane stream (18) to separate nitrogen therefrom; and fractionating (32) the resultant nitrogen-freed bottoms liquid (26) into CO product overheads vapour (35) and methane bottoms liquid (36). If the gaseous mixture also contains argon, argon content can be removed with the methane content to obviate a separate argon-separation stage as required by prior art processes. <IMAGE>