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Title: Gas composition effects on microbial coal desulfurization with a thermophilic bacterium: Sulfolobus acidocaldarius

Conference ·
OSTI ID:5866434

Coal is an important energy source, accounting for over 20% of the energy needs of the United States. Much of the coal utilized in the U.S. is high-sulfur coal, and the combustion of high-sulfur coal generates large amounts of sulfur dioxide. Because of the high cost and low reliability of the present methods to remove sulfur, more cost-effective methods are being sought. An interesting form of pre-combustion sulfur removal is microbial coal desulfurization. An aqueous slurry of coal is inoculated with a culture of sulfur-oxidizing bacteria. Typically, organisms of the genera Sulfolobus, Pseudomonas or Thiobacillus are employed. Microbial action solubilizes iron pyrite readily and removes up to 60% of the organic sulfur. In the present study, a culture of thermophilic sulfur-oxidizing bacteria was applied to 5% coal slurries to effect the oxidation of sulfur in the coal. The thermophilic culture was originally a pure culture of Sulfolobus, but because aseptic technique was not followed, any thermotolerant microorganism present in the coal or in the laboratory may also have been present in the culture. During the microbial oxidation of coal-derived sulfur, the slurry was sparged with air to supply oxygen and carbon dioxide. The oxygen was required by the bacteria as an electron acceptor. Many sulfur-oxidizing microorganisms are autotrophic and require carbon dioxide as a carbon source. Experiments on innoculated coal slurries treated with air enriched in carbon dioxide and oxygen at various mole fractions were run and the results are presented in this paper. The effect of an elevated pressure of air on the rate of microbial desulfurization was also examined.

OSTI ID:
5866434
Report Number(s):
CONF-8609178-
Resource Relation:
Conference: Society of Mining Engineering of AIME fall meeting, St. Louis, MO, USA, 7 Sep 1986; Other Information: Technical Paper 86-355
Country of Publication:
United States
Language:
English