Interpretation of the sulfation rate of CaO, MgO, and ZnO with SO2 and SO3

Published models for gas‐solid reactions have been used with certain modifications to interpret sulfation data for CaO, MgO, and ZnO with SO2 and SO3. None of the models evaluated gave an adequate interpretation for high solid conversions, which were found to exceed 90% in some cases. Such high conversions are inconsistent with the current models, and a new mechanism must be postulated to explain the reaction after the solid product theoretically fills the initial pores of the particle. An important factor in successfully interpreting the experimental data is the distributed nature of the pore sizes within the solid particle.