ENTRAINED BED GASIFICATION OF COAL - PREDICTION OF CONTAMINANT LEVELSUSING THERMODYNAMIC CALCULATIONS

The FA*C*T method was used for predicting the emissions of S-, Cl-, N -, Pb- and As-containing contaminants from entrained bed gasification of one bituminous coal and one subbituminous coal. When the effect of mineral matter was included, the emissions of H2S, CS2, COS, HCl and H CN decreased substantially whereas the amount of predicted NH3 remaine d unaffected. The decrease was offset by increased formation of metal sulphides, chlorides and cyanides. Relatively large amounts of Na, K, Mg, Ca, Pb and As in the gas were predicted by the method. The chlorid es of these metals are also rather volatile. The presence of steam inc reased the amount of H2S and HCl and decreased the amount of HCN in th e products.