| Abstract |
Calcined dolomite is a candidate acceptor for H2S in processes for gasifying or pyrolyzing sulfurous fuels, such as coal and residual oil, to provide sulfur-free fuels for use in power stations. Differential kinetic data are given for the reaction (CaO+MgO) + H2S = (Cas+MgO) + H2O between 475 and 900C at H2S partial pressures between 0.003 and 0.2 atmospheres. The main features of data obtained for a powder appear to be explained by the assumption that activated adsorption of H2S by unreacted CaO hinders the rate, the adsorption being in general not at equilibrium. An expression for the rate appears to require at least three kinetic constants: an adsorption rate constant, a desorption rate constant, and a reaction rate constant. The activation energy of the reation kinetic constant is estimated. Some effects of steam concentration, hydrogen concentration, and sintering on the activity of calcined dolomite are discussed. (Modified author abstract) |
