Experimental evaluation of a class of distributed pore size models for gas-solid reactions with solid product

Abstract

The performance of a mathematical model for transport, reaction, and structure evolution during gas-solid reactions involving porous solids and solid product was evaluated using experimental reactivity evolution data for the sulfidation of porous zinc oxide and the sulfation of limestone calcines. It was found that the mathematical model can satisfactorily approximate the experimental data provided that allowance is made for the formation of inaccessible pore space in the course of the reaction. Comparison of model predictions and experimental data showed that the intraparticle diffusional limitations are among the factors having the most influence on the behavior of these systems. As a result, the variation of the reactivity of the solids is strongly influenced not only by the pore size distribution of the solids but by the connectivity of their pore space as well.