Process for removing hydrogen sulfide from sour gas streams
AssigneeKerr-McGee Refining Corporation
InventorCharles J. Welsh
Life of this patent
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Abstract
A process for removing hydrogen sulfide from a sour gas stream wherein the sour gas stream is contacted with an aqueous alkali metal hydroxide solution containing a stoichiometric excess of the alkali metal hydroxide to provide a sweet gas substantially free of hydrogen sulfide and a partially spent aqueous alkali metal solution. The partially spent aqueous alkali metal solution is contacted with a second sour gas stream in a countercurrent absorber to provide a second sweet gas and a substantially caustic-free aqueous solution of the alkali metal hydrosulfide.
Claims18
An improved process for removing hydrogen sulfide from sour gas streams to provide a sweet gas stream substantially free of hydrogen sulfide and an aqueous sodium hydrosulfide solution, the process comprising:
- contacting a first sour gas stream containing hydrogen sulfide and carbon dioxide with an aqueous alkali metal hydroxide solution containing a stiochiometric excess of alkali metal hydroxide, based on the amount of hydrogen sulfide present in the first sour gas stream, at conditions preferential to the reaction between the alkali metal hydroxide and the hydrogen sulfide to form a mixed phase effluent;
- separating the mixed phase effluent into a gas phase and a partially spent aqueous alkali metal hydroxide solution containing alkali metal hydrosulfide;
- recovering the gas phase as a carbon dioxide-containing first sweet gas stream substantially free of hydrogen sulfide;
- reactively contacting the partially spent alkali metal hydroxide solution with a substantially carbon dioxide-free, non-process-derived second sour gas stream containing hydrogen sulfide;
- and
- recovering a second sweet gas stream and a substantially alkali metal hydroxide-free aqueous solution of alkali metal hydrosulfide.
Dependencies are inferred from the claim text.