Kinetic study of sulfur dioxide absorption into dolomite-brucite suspensions

Abstract

The influence of the dolomite-brucite concentration and temperature on the global process of sulfur dioxide, SO2, absorption into dolomite-brucite suspensions was established. According to the proposed macro-kinetic model, the chemical reaction between H2SO3 and MeCO3 takes place into the adsorbed layer, at the outer surface of the granules. The low values of the activation energies obtained, Ea << 25.1 kJ/mol, confirmed for working conditions, that the global chemisorption process was limited to diffusion stage. At suspension concentrations lower than 5% and high temperatures, the chemisorption was carried out according to the shrinking core model without crust, when the diffusion of H2SO3 through the liquid phase is the limitative stage. At concentrations higher than 10% the chemisorption was carried out according to the unreacted core model with crust formation, when the diffusion of H2SO3 through the crust of products remains the limitative phenomenon.