Kinetics of HCl reactions with calcium and sodium sorbents for IGCC fuel gas cleaning

Abstract

Experiments for HCl sorption by calcium and sodium sorbents have been carried out with simulated gases of compositions typical for "air-blown" and "oxygen-blown" IGCC fuel gases. The concentration of CO2 affects the behaviour of HCl sorption by Ca-sorbents but does not influence the performance of Na-sorbents in the temperature range 300-600 °C. The sorbent particle size has a slight effect on HCl sorption by Na2CO3 in the range 90-250 μm. The optimum temperature for the reaction was found to be between 400 and 500 °C. This has been attributed to a combination of reaction kinetics and sintering. A mathematical model has been developed to simulate gas solid reactions in fixed beds. The coefficient of gas diffusion through the product layer (NaCl) was obtained at 300-600 °C.