Hydrogen processing costs, Claus plant

It is always necessary to remove hydrogen sulfide, and usually necessary to remove carbon dioxide. Any cleanup process which removes both acid gases delivers a stream which is too dilute in H2S to be handled in a Claus plant for elemental sulfur production. As a result, the gas is usually processed twice, once for hydrogen sulfide and later for carbon dioxide, at increased cost. 

Extensive dust removal facilities are required to clean up the sulfur dioxide stream from these sources, which adds substantially to the capital cost of the plant and offsets the raw material cost advantage obtained from these sulfur sources. Sometimes, hydrogen sulfide is simply burned to produce sulfur dioxide when the source of the hydrogen sulfide is near a producing sulfuric acid plant. If this method is used then the need for elemental sulfur production by the Claus process is bypassed. 

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