초록 ▼

A cyclic process for the removal of hydrogen sulfide, and carbon dioxide, from a variety of gas streams is disclosed. The gas stream containing the sour gas(es) is contacted with an aqueous solution of a specific reactant ligand or chelate, or mixtures thereof, optionally in an absorbent, containing

A cyclic process for the removal of hydrogen sulfide, and carbon dioxide, from a variety of gas streams is disclosed. The gas stream containing the sour gas(es) is contacted with an aqueous solution of a specific reactant ligand or chelate, or mixtures thereof, optionally in an absorbent, containing specific stabilizers for improvement of chelate life. The hydrogen sulfide is converted to sulfur, CO 2 may be absorbed to produce a purified gas stream, and the reactant chelate is reduced. The process includes sulfur removal and regeneration of the reactant chelate.

대표청구항 ▼

1. A process for the removal of H 2 S from a sour gaseous stream comprising: (a) contacting the sour gaseous stream in a contacting zone with an aqueous reaction solution at a temperature below the melting point of sulfur, the solution containing an effective amount of a reactant selected from th

1. A process for the removal of H 2 S from a sour gaseous stream comprising: (a) contacting the sour gaseous stream in a contacting zone with an aqueous reaction solution at a temperature below the melting point of sulfur, the solution containing an effective amount of a reactant selected from the group consisting of oxidizing iron chelate compounds, and mixtures thereof, and a stabilizing amount of a composition selected from the group consisting of sodium thiocyanate, sodium dithionite, and mixtures thereof, and producing a sweet gas stream and an aqueous admixture containing crystalline sulfur and a reduced reactant; (b) removing at least a portion of the crystalline sulfur from the aqueous admixture; (c) regenerating the aqueous admixture in a regeneration zone to produce a regenerated reactant; (d) returning aqueous admixture containing regenerated reactant from the regeneration zone to the contacting zone. 2. The process of claim 1 wherein the stream from which the H 2 S is removed is selected from naturally-occurring gases, synthesis gases, process gases and fuel gas. 3. The process of claim 1 wherein the sour gaseous stream is selected from natural gas, a stream derived from the gasification of coal, or a hydrocarbon stream. 4. A process for the removal of H 2 S from a sour gaseous stream comprising: (a) contacting the sour gaseous stream in a contacting zone with an aqueous reaction solution at a temperature below the melting point of sulfur, the solution containing an effective amount of a reactant selected from the group consisting of oxidizing iron chelate compounds, and mixtures thereof, and a stabilizing amount of a composition selected from the group consisting of sodium thiocyanate, sodium dithionite, and mixtures thereof, and producing a sweet gas stream and an aqueous admixture crystalline sulfur and a reduced reactant; (b) regenerating the aqueous admixture in a regeneration zone to produce an aqueous admixture containing a regenerated reactant; (c) removing at least a portion of the crystalline sulfur from aqueous admixture from step (b) to produce an aqueous admixture having reduced sulfur content. (d) returning aqueous admixture having reduced sulfur content to the contacting zone. 5. The process of claim 4 wherein the stream from which the H 2 S is removed is selected from naturally-occurring gases, synthesis gases, process gases and fuel gas. 6. The process of claim 4 wherein the sour gaseous stream is selected from natural gas, a stream derived from the gasification of coal, or a hydrocarbon stream. 7. A process for the removal of H 2 S and CO 2 from a sour gaseous stream comprising: (a) contacting the sour gaseous stream in a contacting zone at a temperature below the melting point of sulfur with a lean CO 2 -selective absorbent mixture containing an effective amount of a reactant selected from the group consisting of oxidizing iron chelate compounds, and mixtures thereof, and a stabilizing amount of a composition selected from the group consisting of sodium thiocyanate, sodium dithionite, and mixtures thereof, and producing a sweet gaseous stream and an absorbent admixture containing absorbed CO 2, crystalline sulfur, and reduced reactant; (b) removing at least a portion of the crystalline sulfur from the absorbent admixture, and leaving a solution containing absorbed CO 2 and reduced reactant; (c) stripping the solution containing absorbed CO 2 and said reduced reactant to remove CO 2, and regenerating said solution, producing a lean CO 2 -selective absorbent solution regenerated reactant; and (d) returning lean CO 2 -selective absorbent solution containing regenerated reactant to the contacting zone. 8. A process for the removal of H 2 S and CO 2 from a sour gaseous stream comprising: (a) contacting the sour gaseous stream in a contacting zone at a temperature below the melting point of sulfur with a lean CO 2 -selective absorbent mixture containing an effective amount of a reactant selected from the group consisting of oxidizing iron chelate compounds, and mixtures thereof, and a stabilizing amount of a composition selected from the group consisting of sodium thiocyanate, sodium dithionite, and mixtures thereof, and producing a sweet gaseous stream and an absorbent mixture containing absorbed CO 2, crystalline sulfur, and reduced reactant; (b) stripping the absorbent mixture containing absorbed CO 2, crystalline sulfur, and said reduced reactant, and regenerated said absorbent mixture, producing a lean CO 2 -selective absorbent solution containing a regenerated reactant and sulfur, (c) removing at least a portion of the crystalline sulfur from the lean CO 2 -selective absorbent solution containing the sulfur and the regenerated reactant, and leaving a lean CO 2 -selective absorbent solution containing regenerated reactant, and (d) returning lean CO 2 -selective absorbent solution containing regenerated reactant to the contacting zone. 9. The process of claim 2 wherein the iron chelate compound is the Fe (III) chelate of nitrilotriacetic acid. 10. The process of claim 2 wherein the iron chelate compound is the Fe (III) chelate of N-(2-hydroxyethyl)ethylenediamine triacetic acid. 11. The process of claim 3 wherein the iron chelate compound is the Fe (III) chelate of nitrilotriacetic acid. 12. The process of claim 3 wherein the iron chelate compound is the Fe (III) chelate of N-(2-hydroxyethyl)ethylenediamine triacetic acid. 13. The process of claim 5 wherein the iron chelate compound is the Fe (III) chelate of nitrilotriacetic acid. 14. The process of claim 5 wherein the iron chelate compound is the Fe (III) chelate of N-(2-hydroxyethyl)ethylenediamine triacetic acid. 15. The process of claim 6 wherein the iron chelate compound is the Fe (III) chelate of nitrilotriacetic acid. 16. The process of claim 6 wherein the iron chelate compound is the Fe (III) chelate of N-(2-hydroxyethyl)ethylenediamine triacetic acid. 17. The process of claim 7 wherein the stream from which the H 2 S is removed is selected from naturally-occurring gases, synthesis gases, process gases and fuel gas. 18. The process of claim 7 wherein the sour gaseous stream is selected from natural gas, a stream derived from the gasification of coal, or a hydrocarbon stream. 19. The process of claim 17 wherein the iron chelate compound is the Fe (III) chelate of nitrolotriacetic acid. 20. The process of claim 17 wherein the iron chelate compound is the Fe (III) chelate of N-(2-hydroxyethyl)ethylenediamine triacetic acid. 21. The process of claim 18 wherein the iron chelate compound is the Fe (III) chelate of nitrilotriacetic acid. 22. The process of claim 18 wherein the iron chelate compound is the Fe (III) chelate of N-(2-hydroxyethyl)ethylenediamine triacetic acid. 23. The process of claim 8 wherein the sour gaseous stream is selected from natural gas, a stream derived from the gasification of coal, or a hydrocarbon stream. 24. The process of claim 8 wherein the sour gaseous stream is selected from natural gas, a stream derived from the gasification of coal, or a hydrocarbon stream. 25. The process of claim 23 wherein the iron chelate is the Fe (III) chelate of nitrilotriacetic acid. 26. The process of claim 23 wherein the iron chelate compound is the Fe (III) chelate of N-(2-hydroxyethyl)ethylenediamine triacetic acid. 27. The process of claim 24 wherein the iron chelate compound is the Fe (III) chelate of nitrilotriacetic acid. 28. The process of claim 24 wherein the iron chelate compound is the Fe (III) chelate of N-(2-hydroxyethyl)ethylenediamine triacetic acid.