- Sour gas
Sour gas is
natural gas or any other gas containing significant amounts ofhydrogen sulfide (H2S). Natural gas is usually considered sour if there are more than 5.7milligram s of H2S per cubic meter of natural gas, which is equivalent to approximately 4 ppm by volume [http://www.naturalgas.org/naturalgas/processing_ng.asp NaturalGas.org website page] "Processing Natural Gas"] .Although the terms "
acid gas " and "sour gas" are used interchangeably, strictly speaking, a sour gas is any gas that contains hydrogen sulfide in significant amounts, whereas anacid gas is any gas that contains significant amounts ofacidic gases such ascarbon dioxide (CO2) or hydrogen sulfide. Thus, carbon dioxide by itself is an acid gas but it is not a sour gas.Before a raw natural gas containing hydrogen sulfide and/or carbon dioxide can be used, the raw gas must be treated to remove those impurities to acceptable levels, commonly by an
amine gas treating process. [ [http://www.eia.doe.gov/pub/oil_gas/natural_gas/feature_articles/2006/ngprocess/ngprocess.pdf Energy Information Agency website page] "Natural Gas Processing: The Crucial Link Between Natural Gas Production and Its Transportation to Market"] The removed H2S is most often subsequently converted to by-product elementalsulfur in aClaus process .Processes within oil refineries or natural gas processing plants that remove
mercaptans and/or hydrogen sulfide are commonly referred to as "sweetening" processes because they result in products which no longer have the sour, foul odors ofmercaptan s and hydrogen sulfide.Hydrogen sulfide is a toxic gas. It also places restrictions on the materials than can be used for
piping and other equipment handling sour gas, as many metals are sensitive tosulfide stress cracking . The presence of hydrogen sulfide in gas causes lower quality burning and the production ofsulfur dioxide , and so is regulated in commercially sold gas.ee also
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Natural gas processing
*Oil refinery
*Rectisol
*Selexol References
Engineering-stub
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