THE SULFIDATION OF CALCINED LIMESTONE WITH HYDROGEN-SULFIDE AND CARBONYL SULFIDE

The sulphidation of calcined limestone with H2S, COS and mixtures of H 2S and COS was studied in a thermogravimetric analyzer at temperatures between 500 and 700 degrees C. The applied H2S- and COS-pressures cor responded with those in coal gas produced by modern coal gasifiers, i. e. 50-12,000 Pa for H2S and 50-1000 Pa for COS. The reaction orders in H2S and COS as well as the activation energies of the involved reacti ons were determined. The mechanism of sulphidation was examined by sim ulating measured conversion vs time behaviour with the grain size dist ribution model of Heesink et al. (1993, Chem. Engng J. 53, 25-37).