Abstract An improved process for removing sulfur oxides from gas mixtures with a solid acceptor for sulfur oxides wherein the solid acceptor is regenerated with a steam-diluted reducing gas and the regeneration off-gas is fed to a Claus sulfur recovery process. The improvement comprises cooling the regeneration off-gas to condense the water vapor contained therein, contacting the cooled off-gas with a sulfur dioxide-selective liquid absorbent, passing the fat liquid absorbent to a buffer zone and then to a stripping zone wherein the absorbed SO2 is recovered from the liquid absorbent and is supplied to the sulfur recovery process. By operating in this manner, fluctuations in the sulfur dioxide concentration of the regeneration off-gas are leveled-out and on relatively concentrated sulfur dioxide stream is supplied to the sulfur recovery process at a substantially constant rate.
The process of claim 1 wherein part of the condensed steam is contacted with the regeneration off-gas to be cooled.
Claim 2
Dependent Claim
30 words
The process of claim 1 wherein the regeneration off-gas is contacted with the liquid absorbent at a temperature between 10*-60* C and a pressure of between 1 and 10 atmospheres.
Claim 3
Dependent Claim
23 words
The process of claim 1 wherein the liquid absorbent is N-methyl pyrrolidone, dimethyl aniline, sulfolane or a mixture of sulfolane, diisopropanolamine and water.
Claim 4
Dependent Claim
11 words
The process of claim 1 wherein the liquid absorbent is water.
Claim 5
Dependent Claim
23 words
The process of claim 5 wherein the absorbed sulfur dioxide is expelled from the liquid absorbent by means of direct heating with steam.
Claim 6
Dependent Claim
25 words
The process of claim 6 wherein part of the steam condensate is mixed with the cooled regeneration off-gas prior to contacting with the liquid absorbent.
Claim 7
Dependent Claim
29 words
The process of claim 5 wherein the regeneration off-gas is contacted with the liquid absorbent at a temperature between 25*-50* C and a pressure between 1.3 and 6.5 atmospheres.
Claim 8
Dependent Claim
25 words
The process of claim 1 wherein two thirds of the sulfur dioxide passed to the Claus sulfur recovery process is catalytically reduced to hydrogen sulfide.
Claim 9
Dependent Claim
20 words
The process of claim 1 wherein the off-gases from the Claus sulfur recovery process are returned to the acceptance process.