The Bureau of Mines, U.S. Department of the Interior, has developed a flue gas desulfurization process as part of its goal of minimizing the undesirable environmental impacts associated with energy and mineral-processing plants. This process, known as the citrate process, involves absorption of sulfur dioxide (so2) in a buffered solution of citric acid. The so2-loaded solution is regenerated by reaction of the so2 with hydrogen sulfide (h2s) to form elemental sulfur. As an adjunct to the citrate process, bench-scale research has shown that so2-loaded citrate or glycolate solutions can be regenerated by countercurrent contact with steam (stripping) in packed towers. Concentrated so2 is produced by condensing the steam from the stripper product. Thus, steam stripping provides strong so2 gas for liquefaction, sulfuric acid production, or reduction to elemental sulfur. Stripping steam requirements were determined for treatment of 0.25-, 0.50-, 1.0-, and 2.0-Pct-so2 waste gases. Steam requirements decreased with increasing so2 concentrations in the simulated waste gases. For example, 5 grams of steam per gram of so2 was required to remove 90 pct of the so2 from a simulated copper smelter gas (2.0 pct so2) while 30 grams of steam per gram of so2 was needed for 90 pct so2 removal from a simulated coal-fired powerplant gas (0.25 pct so2).