| abstract |
A method of removing hydrogen sulfide from a sour gaseous stream in a contact zone by contacting the sour gaseous stream with a H 2 S selective absorbent in an aqueous alkaline solution containing a polyvalent metal chelate at a pH of about 7 to about 10 wherein the polyvalent metal chelate is in one embodiment of the invention in the reduced or lower valence state in a contact zone and is oxidized to the oxidized or higher valence state in an oxidation zone so as to convert absorbed hydrogen sulfide, hydrosulfide and/or sulfide salts present in the contact zone to sulfur. In a second embodiment, the aqueous alkaline solution and H 2 S selective absorbent in contact with the gaseous stream is a mixture containing a higher valence polyvalent metal chelate together with a lower valence polyvalent metal chelate. |