Patent ID: 8647497

Claim:
A method for hydrogen sulfide removal from a sour gas mixture comprising hydrogen sulfide, comprising: providing an aqueous solution comprising a transition metal compound, a transition metal of said transition metal compound being at a first valence and having at least one reduction state from said first valence; reacting said sour gas mixture with said transition metal compound and said aqueous solution in a scrubber, wherein sulfide from said hydrogen sulfide is oxidized to form elemental sulfur and said transition metal is reduced to form a reduced state transition metal compound; performing an electrochemical redox reaction using an electrolyzer, said electrochemical redox reaction including said reduced state transition metal compound to regenerate said transition metal compound in said electrolyzer, said electrolyzer comprising an external power source that supplies power to drive said electrochemical redox reaction, an anode, a cathode, and an electrolyte membrane between said anode and said cathode, wherein during said electrochemical redox reaction a voltage from said external power source applied to said electrolyzer is controlled to regenerate said transition metal compound at a rate sufficient to match a flow rate of said hydrogen sulfide into said scrubber or to maintain a predetermined maximum level of said hydrogen sulfide out from said scrubber, and returning said transition metal compound that is regenerated in said electrochemical redox reaction to said scrubber for said reacting.