Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
165 words
A PROCESS FOR TREATING AN INPUT GAS STREAM CONTAINING SO2 AND O2 IN ORDER TO CONTINUOUSLY REMOVE SO2 THEREFROM, SAID PROCESS COMPRISING THE STEPS OF: A. CONTACTING THE INPUT GAS STREAM WITH AN AQUEOUS ABSORBENT CONTAINING AN ALKALINE REAGENT AND A REDUCING AGENT, SELECTED FROM THE GROUP CONSISTING OF FINELY DIVIDED SULFUR, A POLYSULFIDE COMPOUND, A WATER-SOLUBLE SULFIDE COMPOUND AND MIXTURES THEREOF, AT SCRUBBING AND THIOSULFATE PRODUCTION CONDITIONS SELECTED TO RESULT IN ATREATED GAS STREAM CONTANING A REDUCED AMOUNT OF SO2 AND A EFFLUENT WATER STREAM CONTAINING A WATER-SOLUBLE THIOSULFATE COMPOUND; B. REACTING AT LEAST A PORTION OF THE EFFLUENT STREAM FROM STEP (A) WITH CARBON MONOXIDE AT REDUCTION CONDITIONS SELECETED TO PRODUCE A SULFIDE-CONTAINING AQUEOUS EFFLUENT STREAM; C. STRIPPING HYDROGEN SULFIDE FROM AT LEAST A PORTION OF THE AQUEOUS EFFLUENT STREAM FROM STEP (B) TO PRODUCE A REGENERATED AQUEOUS ABSORBENT STREAM AND ON H2SCONTAINING OVERHEAD STREAM; AND THEREAFTER, D. PASSING AT LEAST A PORTION OF THE RESULTING REGENERATED AQUEOUS ABSORBENT STREAM TO STEP (A).
Claim 2
Dependent Claim
165 words
A PROCESS FOR TREATING AN INPUT GAS STREAM CONTAINING SO2 AND O2 IN ORDER TO CONTINUOUSLY REMOVE SO2 THEREFROM, SAID PROCESS COMPRISING THE STEPS OF: A. CONTACTING THE INPUT GAS STREAM WITH AN AQUEOUS ABSORBENT CONTAINING AN ALKALINE REAGENT AND A REDUCING AGENT, SELECTED FROM THE GROUP CONSISTING OF FINELY DIVIDED SULFUR, A POLYSULFIDE COMPOUND, A WATER-SOLUBLE SULFIDE COMPOUND AND MIXTURES THEREOF, AT SCRUBBING AND THIOSULFATE PRODUCTION CONDITIONS SELECTED TO RESULT IN ATREATED GAS STREAM CONTANING A REDUCED AMOUNT OF SO2 AND A EFFLUENT WATER STREAM CONTAINING A WATER-SOLUBLE THIOSULFATE COMPOUND; B. REACTING AT LEAST A PORTION OF THE EFFLUENT STREAM FROM STEP (A) WITH CARBON MONOXIDE AT REDUCTION CONDITIONS SELECETED TO PRODUCE A SULFIDE-CONTAINING AQUEOUS EFFLUENT STREAM; C. STRIPPING HYDROGEN SULFIDE FROM AT LEAST A PORTION OF THE AQUEOUS EFFLUENT STREAM FROM STEP (B) TO PRODUCE A REGENERATED AQUEOUS ABSORBENT STREAM AND ON H2SCONTAINING OVERHEAD STREAM; AND THEREAFTER, D. PASSING AT LEAST A PORTION OF THE RESULTING REGENERATED AQUEOUS ABSORBENT STREAM TO STEP (A).
Claim 3
Dependent Claim
22 words
A process as defined in claim 1 wherein the alkaline reagent utilized in the absorbent is ammonium carbonate, bicarbonate, hydroxide or sulfite.
Claim 4
Dependent Claim
24 words
A process as defined in claim 1 wherein the alkaline reagent utilized in the absorbent is an alkali metal hydroxide, carbonate, bicarbonate or sulfite.
Claim 5
Dependent Claim
13 words
A process as defined in claim 3 wherein the alkali metal is sodium.
Claim 6
Dependent Claim
13 words
A process as defined in claim 3 wherein the alkali metal is potassium.
Claim 7
Dependent Claim
25 words
A process as defined in claim 1 wherein the alkaline reagent utilized in the absorbent stream is an alkaline earth metal hydroxide, carbonate or sulfite.
Claim 8
Dependent Claim
28 words
A process as defined in claim 1 wherein the scrubbing and thiosulfate production conditions utilized in step (a) include a temperature of about 10* to about 100* C.
Claim 9
Dependent Claim
41 words
A process as defined in claim 1 wherein the reduction conditions utilized in step (b) include a temperature of about 100* to about 350* C. and a pressure sufficient to maintain the effluent stream from step (a) in the liquid phase.
Claim 10
Dependent Claim
33 words
A process as defined in claim 1 wherein the amount of carbon monoxide charged to step (b) is sufficient to provide a mole ratio of carbon monoxide to thiosulfate of at leat 4:1.
Claim 11
Dependent Claim
31 words
A process as defined in claim 1 wherein the reducing agent utilized in step (a) is obtained by passing a portion of the effluent stream from step (b) to step (a).
Claim 12
Dependent Claim
44 words
A process as defined in claim 1 wherein the reducing agent utilized in step (a) is obtained by controlling the stripping conditions used in step (c) so that sufficient sulfide remains in the regenerated aqueous absorbent stream which is thereafter passed to step (a).
Claim 13
Dependent Claim
33 words
A process as defined in claim 1 wherein the amount of reducing agent charged to step (a) is sufficient to convert at least 90% of the absorbed SO2 to the corresponding thiosulfate compound.
Claim 14
Dependent Claim
51 words
A process as defined in claim 1 wherein step (b) is performed in the presence of a catalyst comprising a catalytically effective amount of a metallic component selected from the group consisting of the transition metals of Groups VI and VIII of the Periodic Table combined with a porous carrier material.
Claim 15
Dependent Claim
28 words
A process as defined in claim 1 wherein the catalyst used in step (b), comprises a catalytically effective amount of cobalt sulfide combined with activated carbon or alumina.
Claim 16
Dependent Claim
35 words
A process as defined in claim 1 wherein the stripping conditions utilized in step (c) include a temperature of about 100* to about 200* C. and a pressure of about 1 to about 750 psig.
Claim 17
Dependent Claim
19 words
A process as defined in claim 1 wherein step (c) is performed with a stripping gas comprising carbon dioxide.