Abstract A selective method of removing sulfur dioxide from flue gases or the like containing both sulfur dioxide and hydrogen sulfide without removing the hydrogen sulfide by bubbling the flue gas through about a 5-95 percent solution of an organic acid and an alkali metal salt of the said acid. The acid is selected from the group of: citric malic, lactic, succinic, ascorbic and tartaric. The acid is preferably citric and the alkali metal is preferably potassium. The ratio of the weight of the salt to that of the acid may be within the range of about 1s: 2a to 6s: 1a as such as is needed to make the solution pH between about 4.0 and 6.0, where s and a are one mole each of said salt and said acid, respectively. The said ratio preferably is 5s:1a or the pH is preferably 5.7.
The invention as defined in claim 1, wherein said solution has a concentration of between about 5 percent to about 95 percent.
Claim 2
Dependent Claim
33 words
The invention as defined in claim 2, wherein the ratio of the weight of said salt to said acid is such that the pH of said solution is between about 4.0 and 6.0.
Claim 3
Dependent Claim
18 words
The invention as defined in claim 3, wherein said acid is citric acid, said salt being potassium citrate.
Claim 4
Dependent Claim
20 words
The invention as defined in claim 4, wherein said concentration is about 95 percent and said pH is about 5.7.
Claim 5
Dependent Claim
42 words
The invention as defined in claim 1, wherein the ratio of the weight of said salt to said acid is from about 1s:2a to about 6s: 1a, where s and a are one mole each of said salt and said acid, respectively.
Claim 6
Dependent Claim
18 words
The invention as defined in claim 6, wherein said acid is citric acid, said salt being potassium citrate.
Claim 7
Dependent Claim
20 words
The invention as defined in claim 7, wherein said concentration is about 95 percent and said ratio is about 5s:1a.