Regenerative recovery of contaminants from effluent gases

Abstract

This invention relates to processes for the selective removal of contaminants from effluent gases. More particularly, various embodiments of the present invention relate to selective removal and recovery of sulfur dioxide from effluent gases in a regenerative sulfur dioxide absorption/desorption process that achieves favorable energy efficiency. Energy is recovered from a wet stripper overhead gas stream produced in the desorption cycle by indirect transfer of heat from the stripper gas to a cooling medium and used to generate steam for use in stripping contaminants from the absorption liquor. The absorption zone may optionally be cooled to enhance the capacity of the absorption medium for absorption of a contaminant gas, thereby lowering the volume of absorption medium and contaminant-enriched absorption liquor that must be pumped, handled, heated and cooled in the absorption/desorption cycle.