Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
99 words
A METHOD FOR REMOVING H2S FROM A GAS STREAM CONTAINING H2S AND CO2 WITHOUT SUBSTANTIALLY AFFECTING THE CO2 CONTENT OF THE GAS STREAM, WHICH COMPRISES CONTACTING THE GAS STREAM WITH AN AQUEOUS SOLUTION OF A WATER-SOLUBLE SULFITE AT A PH OF ABOUT 6 TO ABOUT 7, A TEMPERATURE OF ABOUT 20* TO ABOUT 150* C. AND A MOLE RATIO OF HYDROGEN SULFIDE TO SULFITE OF LESS THAN 0.5:1, WHEREBY TO FORM A TREATED GAS STREAM WHICH IS SUBSTANTIALLY REDUCED IN H2S CONTENT AND A RICH ABSORBENT STREAM CONTAINING A THIOSULFATE COMPOUND AND WHICH IS SUBSTANTIALLY FREE OF ELEMENTAL SULFUR.
Claim 2
Independent Claim
99 words
A METHOD FOR REMOVING H2S FROM A GAS STREAM CONTAINING H2S AND CO2 WITHOUT SUBSTANTIALLY AFFECTING THE CO2 CONTENT OF THE GAS STREAM, WHICH COMPRISES CONTACTING THE GAS STREAM WITH AN AQUEOUS SOLUTION OF A WATER-SOLUBLE SULFITE AT A PH OF ABOUT 6 TO ABOUT 7, A TEMPERATURE OF ABOUT 20* TO ABOUT 150* C. AND A MOLE RATIO OF HYDROGEN SULFIDE TO SULFITE OF LESS THAN 0.5:1, WHEREBY TO FORM A TREATED GAS STREAM WHICH IS SUBSTANTIALLY REDUCED IN H2S CONTENT AND A RICH ABSORBENT STREAM CONTAINING A THIOSULFATE COMPOUND AND WHICH IS SUBSTANTIALLY FREE OF ELEMENTAL SULFUR.
Claim 3
Dependent Claim
14 words
A method as defined in claim 1 wherein said water-soluble sulfite is ammonium sulfite.
Claim 4
Dependent Claim
16 words
A method as defined in claim 1 wherein said water-soluble sulfite is an alkali metal sulfite.
Claim 5
Dependent Claim
13 words
A method as defined in claim 3 wherein the alkali metal is sodium.
Claim 6
Dependent Claim
13 words
A method as defined in claim 3 wherein the alkali metal is potassium.
Claim 7
Dependent Claim
17 words
A method as defined in claim 1 wherein the water-soluble sulfite is water-soluble alkaline earth metal sulfite.
Claim 8
Dependent Claim
31 words
A method as defined in claim 1 wherein the mole ratio of hydrogen sulfide to sulfite charged to the contacting step is in the range of about 0.05:1 to about 0.4:1.
Claim 9
Dependent Claim
23 words
A method as defined in claim 1 wherein the pH of said solution entering the contacting step is about 6.3 to about 6.7.
Claim 10
Dependent Claim
36 words
A method as defined in claim 1 wherein said aqueous solution contains a mixture of a water-soluble sulfite and a water-soluble bisulfite in a mole ratio of sulfite to bisulfite of about 0.5:1 to about 5:1.
Claim 11
Dependent Claim
17 words
A method as defined in claim 9 wherein the mole ratio of sulfite to bisulfite is 1:1.
Claim 12
Dependent Claim
31 words
A method as defined in claim 1 wherein the contacting is effected at a temperature of about 25* to about 100* C. and a pressure of about 10 to 500 psig.
Claim 13
Independent Claim
146 words
A method for removing H2S from a gas stream containing a minor amount of H2S and a major amount of CO2 without substantially affecting the CO2 content of the gas stream, the method comprising contacting the gas stream in an absorption zone with an aqueous solution of sodium sulfite and sodium bisulfite in amounts corresponding to a mole ratio of sulfite to bisulfite of about 0.5:1 to about 5:1, said contacting being performed at a pH of about 6 to about 7, a temperature of about 20* to about 150* C., a mole ratio of hydrogen sulfide to total sulfite of less than 0.5:1, and a pressure sufficient to maintain the absorbent stream in the liquid phase, whereby to form a treated gas stream substantially reduced in H2S content and a rich absorbent stream which contains sodium thiosulfate and which is substantially free of elemental sulfur.
Claim 14
Independent Claim
146 words
A method for removing H2S from a gas stream containing a minor amount of H2S and a major amount of CO2 without substantially affecting the CO2 content of the gas stream, the method comprising contacting the gas stream in an absorption zone with an aqueous solution of sodium sulfite and sodium bisulfite in amounts corresponding to a mole ratio of sulfite to bisulfite of about 0.5:1 to about 5:1, said contacting being performed at a pH of about 6 to about 7, a temperature of about 20* to about 150* C., a mole ratio of hydrogen sulfide to total sulfite of less than 0.5:1, and a pressure sufficient to maintain the absorbent stream in the liquid phase, whereby to form a treated gas stream substantially reduced in H2S content and a rich absorbent stream which contains sodium thiosulfate and which is substantially free of elemental sulfur.
Claim 15
Dependent Claim
27 words
A method as defined in claim 12 wherein the pH of said solution entering the absorption zone is in the range of about 6.3 to about 6.7.