Kinetics of H2S Reaction with Calcined Calcium-Based Sorbents

Abstract

Sulfidation experiments at atmospheric pressure in a thermogravimetric analyzer were performed with two calcined limestones and a fully calcined dolomite at temperatures between 450 and 700 °C and with sorbent particle sizes between 0.4 and 1.6 mm. The effects of reaction temperature, sorbent particle size, and H2S concentration were analyzed. The sulfidation rate of the dolomite and a limestone increased with temperature in all of the ranges tested. However, the sulfidation rate of the other limestone increased with temperature until 600 °C and was nearly constant from this temperature. The temperature effect on the conversion versus time curves diminished with increasing particle size. At low temperatures (<500−550 °C) the sulfidation rate did not depend on sorbent particle size. On the other hand, at temperatures above 500−550 °C the sulfidation rate increased with decreasing sorbent particle size due to the effect of the intraparticle diffusion. This finding was in agreement with the SEM-EDX sulfur di...