Patent ID: 6998099

Claim:
A process for the catalytic removal of H 2 S gas from a sour gas stream comprising: a) reducing the amount of H 2 S in the sour gas stream by reacting the H 2 S-containing sour gas stream with an aqueous solution containing a metal chelate complex, a chelate ligand of the general formula (I) being used where: X is hydrogen, an alkali metal or NH 4 + , n is 1, 2 or 3, and at least one of the radicals R 1 to R 6 is alkyl, aryl, alkyloxy, aryloxy, carboxyl, or hydroxyl, the remaining radicals being hydrogen, and the metal in the metal chelate complex is a polyvalent metal, which can occur in more than one oxidation state; at least a part of the metal, after reaction of the H 2 S-containing sour gas stream, being present in a lower oxidation state (reduced form) than before the reaction; b) regenerating the mixture obtained in step a) comprising elemental sulfur and the metal chelate complex, in which at least a part of the metal is present in reduced form, with an oxidizing agent, the reduced form of the metal being oxidized to the metal in the original oxidation state; and c) recirculating the regenerated polyvalent metal chelate complex to step a); with steps a) and b) being able to be carried out in a single reaction vessel.