Occurrence
Small amounts of hydrogen sulfide occur in crude petroleum, but natural gas can contain up to 90%. Volcanoes and some hot springs (as well as cold springs) emit some H2S, where it probably arises via the hydrolysis of sulfide minerals, i.e. MS + H2O → MO + H2S. Hydrogen sulfide can be present naturally in well water, often as a result of the action of sulfate-reducing bacteria.
About 10% of total global emissions of H2S is due to human activity. By far the largest industrial route to H2S occurs in petroleum refineries: The hydrodesulfurization process liberates sulfur from petroleum by the action of hydrogen. The resulting H2S is converted to elemental sulfur by partial combustion via the Claus process, which is a major source of elemental sulfur. Other anthropogenic sources of hydrogen sulfide include coke ovens, paper mills (using the sulfate method), and tanneries. H2S arises from virtually anywhere where elemental sulfur comes in contact with organic material, especially at high temperatures.
Read more about this topic: Hydrogen Sulfide
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