ABSORPTION WITH INSTANTANEOUS REACTION IN A DROPLET WITH SPARINGLY SOLUBLE FINES

The problem of gas absorption followed by an instantaneous irreversible chemical reaction in a rigid droplet containing sparingly soluble fine reactant particles is considered. A model is developed for the general case when the reactant particles dissolution near the gas-liquid interface is non-negligible. Solids dissolution is treated taking into account the average spacing between the suspended particles. A simple analytical expression for the rate of gas absorption is derived under the assumption of slow particles dissolution, and conditions are given for applicability of the model. A numerical example, relevant for the spray-dry desulfurization process, for the system SO2-Ca(OH)2 in water is discussed.