Abstract: A process for removing hydrogen sulfide from sour gas streams is disclosed which is carried out in processing equipment which includes steel components resulting in iron from the steel slowly dissolving in the alkaline H.sub.2 S absorption medium. The solubilized iron tends to react with the hydrogen sulfide to form iron sulfide which further oxidizes to produce sodium thiosulfate. The preferred absorption medium includes a metal vanadate and boron complex, a quinone type reoxidation catalyst and a metal ferri or ferrocyanide decahydrate compound capable of reacting with the solubilized iron in the alkaline absorption medium to form a precipitate which is unreactive with the dissolved hydrogen sulfide.

Abstract: A process for removing hydrogen sulfide from sour gas streams is provided wherein the sour gas is passed in cocurrent flow relationship with a liquid alkaline absorption solution containing a vanadium-boron complex characterized by the properties of reacting with the H.sub.2 S thereby oxidizing [HS.sup.- ] to elemental sulfur in conjunction with reduction of the vanadium while the boron constituent is functional to inhibit formation of insoluble vanadium sulfide compounds. Regeneration of the absorption medium by contact with an oxygen containing gas is enhanced by the provision of an iron-polyamine organic acid oxidation catalyst in the absorption liquid. The process is a direct replacement for and may be operated far more economically than conventional Stretford processes.