Within
oil refineries or
natural gas processing plants, the removal of hydrogen sulfide and other
organosulfur compounds is referred to as "sweetening". The sweetened product lacks the sour, foul odors of
mercaptans and hydrogen sulfide. Before raw natural gas containing hydrogen sulfide or carbon dioxide can be used, the raw gas must be treated to remove those impurities to acceptable levels, commonly by an amine treatment process. The removed H2S is most often subsequently converted to by-product elemental
sulfur in a
Claus process or it can be treated in a
wet sulfuric acid process unit where the by-product is
sulfuric acid. Alternatively, the highly concentrated H2S gas, the by-product of the amine treatment plant, can be recompressed by
gas compressor units specifically designed to handle highly toxic gas and injected back in the reservoir. In addition to utilizing an amine or Claus process, liquid
redox is becoming increasingly popular. Another product removed during sweetening is
carbonyl sulfide. ==See also==