Process for the removal of H2 S and CO2 from gaseous streams

Claim 2

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 contact zone with a lean CO 2 -selective liquid absorbent mixture comprising diethylene glycol monoethyl ether and an effective amount of the Fe(III) chelate of nitrilotriacetic acid, and producing a sweet gaseous stream and a liquid absorbent admixture containing absorbed CO 2 , solid sulfur, and Fe(II) chelate of nitrilotriacetic acid, (b) removing sulfur from said absorbent admixture, and leaving a solution containing absorbed CO 2 and Fe(II) chelate of nitrilotriacetic acid, (c) stripping the solution containing absorbed CO 2 and said Fe(II) chelate, and regenerating Fe(III) chelate of nitrilotriacetic acid in said solution with oxygen, producing a lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid, and (d) returning lean CO 2 -selective absorbent solution containing Fe(III) chelate of nitrilotriacetic acid to the contacting zone.

Claim 3

The method of claim 1 wherein the stream from which the H 2 S and CO 2 are removed is selected from naturally occurring gases, synthesis gases, process gases, and fuel gases.

Claim 4

The method of claim 2 wherein the sour gaseous stream is a stream derived from the gasification and partial oxidation of a liquid hydrocarbon.

Claim 5

The process of claim 2 wherein heat is supplied in step (c) to assist in regeneration.

Claim 6

The method of claim 2 wherein the stream from which the H 2 S and CO 2 are removed is a fuel gas stream produced by gasification of a material selected from coal, petroleum, oil shale, or tar sands.

Claim 7

The method of claim 5 wherein the sour gaseous stream is a stream derived from the gasification of coal.

Claim 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 with a lean CO 2 -selective liquid absorbent mixture comprising diethylene glycol monoethyl ether and an effective amount of the Fe(III) chelate of nitrilotriacetic acid, and producing a sweet gaseous stream and a liquid absorbent admixture containing absorbed CO 2 , solid sulfur, and Fe(II) chelate of nitrilotriacetic acid, (b) stripping said admixture containing absorbed CO 2 , sulfur, and said Fe(II) chelate to remove CO 2 , and then regenerating the Fe(III) chelate of nitrilotriacetic acid in said admixture with oxygen, producing a lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid, and sulfur, (c) removing sulfur from the lean CO 2 -selective absorbent solution containing the sulfur and the Fe(III) chelate of nitrilotriacetic acid, and leaving a lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid, and (d) returning lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid to the contacting zone.

Claim 9

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 with a lean CO 2 -selective liquid absorbent mixture comprising diethylene glycol monoethyl ether and an effective amount of the Fe(III) chelate of nitrilotriacetic acid, and producing a sweet gaseous stream and a liquid absorbent admixture containing absorbed CO 2 , solid sulfur, and Fe(II) chelate of nitrilotriacetic acid, (b) stripping said admixture containing absorbed CO 2 , sulfur, and said Fe(II) chelate to remove CO 2 , and then regenerating the Fe(III) chelate of nitrilotriacetic acid in said admixture with oxygen, producing a lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid, and sulfur, (c) removing sulfur from the lean CO 2 -selective absorbent solution containing the sulfur and the Fe(III) chelate of nitrilotriacetic acid, and leaving a lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid, and (d) returning lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid to the contacting zone.

Claim 10

The method of claim 7 wherein the stream from which the H 2 S and CO 2 are removed is selected from naturally occurring gases, synthesis gases, process gases, and fuel gases.

Claim 11

The process of claim 8 wherein heat is supplied in step (b) to assist in regeneration.

Claim 12

The method of claim 8 wherein the sour gaseous stream is a stream derived from the gasification and partial oxidation of a liquid hydrocarbon.

Claim 13

The method of claim 8 wherein the stream from which the H 2 S and CO 2 are removed is a fuel gas stream produced by gasification of a material selected from coal, petroleum, oil shale, or tar sands.

Claim 14

The method of claim 11 wherein the sour gaseous stream is a stream derived from the gasification coal.

Claim 15

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 with a lean CO 2 -selective liquid absorbent mixture comprising diethylene glycol monoethyl ether and an effective amount of the Fe(III) chelate of nitrilotriacetic acid, and producing a sweet gaseous stream and a liquid absorbent admixture containing absorbed CO 2 , solid sulfur, and Fe(II) chelate of nitrilotriacetic acid, (b) removing sulfur from said absorbent admixture, and leaving a solution containing absorbed CO 2 and Fe(II) chelate of nitrilotriacetic acid, (c) stripping the solution containing absorbed CO 2 and said Fe(II) chelate and regenerating the Fe(III) chelate of nitrilotriacetic acid in said solution with oxygen, producing a lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid, and (d) returning lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid to the contacting zone.

Claim 16

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 with a lean CO 2 -selective liquid absorbent mixture comprising diethylene glycol monoethyl ether and an effective amount of the Fe(III) chelate of nitrilotriacetic acid, and producing a sweet gaseous stream and a liquid absorbent admixture containing absorbed CO 2 , solid sulfur, and Fe(II) chelate of nitrilotriacetic acid, (b) removing sulfur from said absorbent admixture, and leaving a solution containing absorbed CO 2 and Fe(II) chelate of nitrilotriacetic acid, (c) stripping the solution containing absorbed CO 2 and said Fe(II) chelate and regenerating the Fe(III) chelate of nitrilotriacetic acid in said solution with oxygen, producing a lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid, and (d) returning lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid to the contacting zone.

Claim 17

The method of claim 13 wherein the stream from which the H 2 S and CO 2 are removed is selected from naturally occurring gases, synthesis gases, process gases, and fuel gases.

Claim 18

The method of claim 14 wherein the sour gaseous stream is a stream derived from the gasification and partial oxidation of a liquid hydrocarbon.

Claim 19

The process of claim 14 wherein heat is supplied in step (c) to assist in regeneration.

Claim 20

The method of claim 14 wherein the stream from which the H 2 S and CO 2 are removed is a fuel gas stream produced by gasification of a material selected from coal, petroleum, oil shale, or tar sand.

Claim 21

The method of claim 17 wherein the sour gaseous stream is a stream derived from the gasification of coal.

Claim 22

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 with a lean CO 2 -selective liquid absorbent mixture comprising diethylene glycol monoethyl ether and an effective amount of the Fe(III) chelate of nitrilotriacetic acid, and producing a sweet gaseous stream and a liquid absorbent admixture containing absorbed CO 2 , solid sulfur, and the Fe(II) chelate of nitrilotriacetic acid, (b) stripping said admixture containing absorbed CO 2 , sulfur and said Fe(II) chelate and regenerating the Fe(III) chelate of nitrilotriacetic acid in said admixture with oxygen, producing a lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid, and sulfur, (c) removing sulfur from the lean CO 2 -selective absorbent solution containing the sulfur and the Fe(III) chelate of nitrilotriacetic acid, and leaving a lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid, and (d) returning lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid to the contacting zone.

Claim 23

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 with a lean CO 2 -selective liquid absorbent mixture comprising diethylene glycol monoethyl ether and an effective amount of the Fe(III) chelate of nitrilotriacetic acid, and producing a sweet gaseous stream and a liquid absorbent admixture containing absorbed CO 2 , solid sulfur, and the Fe(II) chelate of nitrilotriacetic acid, (b) stripping said admixture containing absorbed CO 2 , sulfur and said Fe(II) chelate and regenerating the Fe(III) chelate of nitrilotriacetic acid in said admixture with oxygen, producing a lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid, and sulfur, (c) removing sulfur from the lean CO 2 -selective absorbent solution containing the sulfur and the Fe(III) chelate of nitrilotriacetic acid, and leaving a lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid, and (d) returning lean CO 2 -selective absorbent solution containing the Fe(III) chelate of nitrilotriacetic acid to the contacting zone.

Claim 24

The method of claim 19 wherein the stream from which the H 2 S and CO 2 are removed is selected from naturally occurring gases, synthesis gases, process gases, and fuel gases.

Claim 25

The process of claim 20 wherein heat is supplied in step (b) to assist in regeneration.

Claim 26

The method of claim 20 wherein the sour gaseous stream is a stream derived from the gasification and partial oxidation of a liquid hydrocarbon.

Claim 27

The method of claim 20 wherein the stream from which the H 2 S and CO 2 are removed is a fuel gas stream produced by gasification of a material selected from coal, petroleum, oil shale, or tar sands.

Claim 28

The method of claim 23 wherein the sour gaseous stream is derived from the gasification coal.