Potassium carbonate solutions hydrogen sulfide absorption

CATACARB [Catalyzed removal of carbon dioxide] A process for removing carbon dioxide and hydrogen sulfide from gas streams by absorption in hot potassium carbonate solution containing a proprietary catalyst. Developed and licensed by Eickmeyer and Associates, KS, based on work at the U.S. Bureau of Mines in the 1950s. More than a hundred plants were operating in 1997. See also Benfield, Carsol, Hi-pure, Giammarco-Vetrocoke. 

Combinations of physical and chemical absorption are also used, as in Shell s Sulfinol process in which a mixture of diisopropanolamine and sulfolane in water is utilized. For the hydrogen sulfide-free gases from the steam-reforming process, chemical scrubbing with activated potassium carbonate solutions or alkanolamines is preferred. In the case of hydrogen sulfide-containing gases from the partial oxidation process, physical absorption alone or in combination with chemical absorption is preferred. 

The Catacarb process, which was disclosed by Eickmeyer (1962), is licensed by Eickmey-er and Associates of Prairie Village, Kansas. For most applications the Catacarb process utilizes a catalyzed hot potassium carbonate solution however, potassium borate solutions are used for the removal of hydrogen sulfide in the absence of carbon dioxide (Gangriwala and Chao, 1985). The solutions contain undisclosed additives that catalyze absorption and desorption of acid gases, particularly carbon dioxide. The additives, which include a corrosion inhibitor, are claimed to have no effect on reformer or methanation catalysts that the purified gas may pass through downstream of the Catacarb absorber (Morse, 1968). 

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