The H2S must be
removed (called "sweetening" the gas) before the gas can be utilized. If H S is present, the gas is usually 2
sweetened by absorption of the H S in an amine solution. Amine processes are used for over 95 percent of 2
all gas sweetening in the United States. Other methods, such as carbonate processes, solid bed absorbents,
and physical absorption, are employed in the other sweetening plants. Emission data for sweetening
processes other than amine types are very meager, but a material balance on sulfur will give accurate
estimates for sulfur dioxide (SO ).