Sulfur dioxide emission control by hydrogen sulfide reaction in aqueous solution. The citrate system.
Rosenbaum-JB; McKinney-WA; Beard-HR; Crocker-L; Nissen-WI
Salt Lake City, UT: U.S. Department of the Interior, Bureau of Mines, RI-7774, 1973 Jan; :1-31
Prolonged laboratory and limited pilot plant tests have shown that the Bureau of Mines buffered so2-h2s process is capable of removing 95 to 99 percent of the so2 from industrial waste gases. Most of the so2 is converted to elemental sulfur; only about 1 percent is converted to sulfate. The process comprises (1) washing the flue gas to remove particulates and so3, (2) absorption of the so2 in citric acid or other carboxylate solution, (3) reaction of the loaded solution with h2s in a closed vessel to precipitate the absorbed so2 as elemental sulfur, and (4) separation of the sulfur from the regenerated solution by oil flotation and melting. Two- thirds of the molten sulfur is converted to h2s for use in the sulfur precipitation step by reacting sulfur vapor with natural gas and steam in the presence of an alumina catalyst. The chemistry and mechanism of the process are described, initial laboratory and pilot plant data are summarized, and second-generation laboratory operation and pilot plant design are reviewed. Preliminary cost estimates are presented for recovering sulfur from copper smelter gas, powerplant flue gas, and claus plant tail gas.
IH; Report of Investigations
NTIS Accession No.
Salt Lake City, UT: U.S. Department of the Interior, Bureau of Mines, RI 7774