Dolomite, sulfur capture

Sulfur Emissicms Sulfur present in a fuel is released as SO2, a known contributor to acid rain deposition. By adding limestone or dolomite to a fluidized bed, much of this can be captured as calcium sulfate, a dry nonhazardous solid. As limestone usually contains over 40 percent calcium, compared to only 20 percent in dolomite, it is the preferred sorbent, resulting in lower transportation costs for the raw mineral and the resulting ash product. Moreover, the high magnesium content of the dolomite makes the ash unsuitable for some building applications and so reduces its potential for utilization. Whatever sorbent is selected, for economic reasons it is usually from a source local to the FBC plant. If more than one sorbent is available, plant trials are needed to determine the one most suitable, as results from laboratory-scale reactivity assessments are unreliable. 

Poersch, W., R. Bahnen and R. Wagner (1989), "Burnout and Emissions During the Combustion of Anthracite in the Circofluid Fluidized Bed Combustor", in Proc. of 10th Int. Conf. on Fluidized Bed Combustion, San Francisco, 1175-1183 Reid, W.T. (1970), "Basic Factors in the Capture of Sulfur Dioxide by Limestone and Dolomite", J. Eng. Power, Jan. 1970, 11-16... 

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