Desulfurization of carbon dioxide-containing gases

Abstract

Sulfur-containing compounds are removed from crude COby conversion to elemental sulfur in a Claus process and subsequently by hydrogenation of the Claus tail gas to convert residual sulfur-containing compounds into HS which, after cooling to knock out water and then compressing, is removed, together with any other sulfur-containing impurities, either by physical separation or by chemical reaction with a solid metal oxide to form solid metal sulfide with subsequent oxidative regeneration to produce purified COand a recycle gas comprising at least one sulfur-containing compound which is recycled to the Claus process. Some HS in the Claus tail gas may be removed initially by selective and/or non-selective amine absorption(s) in a tail gas treatment unit prior to removal of residual HS and any other residual sulfur-containing impurities by the physical separation or the chemical reaction steps.