MICROBIAL COAL DESULFURIZATION - CALCULATION OF COSTS

The sulphur found in coal is either part of the molecular structure, is contained in minerals such as pyrite (FeS2), or occurs in minor quantities in the form of sulfate. When pyrite crystals are finely distributed within the coal matrix, mechanical cleaning can only remove part of the pyrite. It can, however, be removed by microbial action requiring only mild reaction conditions. The process involves simple equipment, almost no chemicals, but relatively long reaction times and, eventually, disposal of dissolved iron sulfate. Investment and operating costs are estimated for different process configurations on an industrial scale. © 1990 Springer-Verlag.