The sorption of sulfur and alkali species and the effects of interaction between sorbents used for removal of these species and the coal ash in its various modes of appearance in heat engine combustion systems were studied. Predictive models for sulfur and alkali sorption and to obtain estimates for the capture of these species in potential heat engine applications. It is necessary to control the sulfur emissions because the oxides of sulfur have been identified as precursors to acid rain and also react within and subsequent to the combustion process to form species, such as alkali sulfates, which may be transported to and react to produce corrosive deposits on the surfaces of the heat engine power train. Candidate sorbents for removing these species from the gas phase include lime and dolomite materials for the sulfur oxides, and aluminosilicates for the alkalis. These sorbents were evaluated in the high presure region appropriate to heat engine applications.