Process for acid gas removal from gaseous mixtures

Claim 1

A hybrid physical-chemical absorbent process for removal of gaseous CO 2 and H 2 S from an acidic gas stream introduced at above about 200 psi and which has a mole ratio of CO 2 /H 2 S of about 25 to 50 and CO 2 content of about 15 to 40 mole percent comprising: absorbing CO 2 and H 2 S by passing a gas stream containing CO 2 and H 2 S in countercurrent flow to a liquid organic physical solvent in a physical solvent absorber, CO 2 being absorbed to a treated gas output level of less than 3 mole percent CO 2 and H 2 S to a treated gas output level of less than 1 ppm sulfur containing compound as sulfur; regenerating said organic physical solvent for recycle in said physical solvent absorber by removing the CO 2 -H 2 S gaseous mixture from the physical solvent principally by reduction of pressure, separating the H 2 S from the CO 2 by an H 2 S selective liquid chemical solvent, then passing the CO 2 in countercurrent flow in a physical solvent stripper to the physical solvent liquid obtained from said pressure reduction further removing H 2 S from said physical solvent recycle and returning the physical solvent containing less than 5 ppm sulfur in a sulfur containing compound and less than 2 mole percent CO 2 to said physical solvent absorber; and removing sulfur from said CO 2 gas stream from said physical solvent stripper by passing in countercurrent flow to said chemical solvent sufficient to provide CO 2 effluent to the atmosphere containing less than 7 ppm sulfur in a sulfur containing compound.