Process and device for treating a gas containing hydrogen sulfide, with recycling of the reduced catalytic solution

• Main Authors: Barrere-Tricca, Cécile, Huard, Thierry, Streicher, Christian
• Format: Patent
• Language: English
• Published: 08.07.2003

The present invention relates to an improved process intended for desulfurization of a gaseous feed containing hydrogen sulfide in order to eliminate more readily the elementary sulfur contained in a catalytic desulfurization solution and formed by chemical oxidation reduction reaction after a contacting stage. At least part of the catalytic solution from the contacting stage, containing elemental sulfur, is therefore recycled to the absorption stage under selected conditions allowing to increase the average size of the sulfur grains and notably to reduce the number of sulfur grains of very small size. A process intended for desulfurization of a gaseous feed containing hydrogen sulfide, includes at least the following stages: a) contacting the gaseous feed with a catalytic solution containing at least one polyvalent metal chelated by at least one chelating agent, under suitable conditions for oxidation of the hydrogen sulfide to elemental sulfur and concomitant reduction of the polyvalent metal from a higher oxidation level to a lower oxidation level, b) recovering on the one hand a gaseous effluent substantially freed from hydrogen sulfide and, on the other hand, the catalytic solution at least reduced and containing elemental sulfur, and c) recycling at least a fraction Fof the catalytic solution at least reduced and containing solid elemental sulfur to absorption stage a) so as to reduce the number of sulfur grains of very small size.