Utilization of novel Ca-based sorbents for H2S removal in coal gas cleaning at high temperatures

The effectiveness of calcium acetate (CA), and calcium magnesium acetate (CMA) as feasible H2S capture agents was tested in an entrained flow reactor at temperatures up to 1100 degrees C. Sulfur capture up to 90%, near to the thermodynamic equilibrium was achieved with dry powders injection of CA and CMA at furnace gas temperatures of about 1000 degrees C and 800 degrees C, respectively, a Ca/S molar ratio of 2, and 0.8 seconds of residence time. Although more expensive, the sulfur capture effectiveness of these sorbents was superior to any other natural calcium-based sorbent. Both sorbents have the ability to form highly porous and reactive cenospheric oxide particles on heating to high temperatures, which are later of easy stabilization. These qualities make them very attractive materials to remove H2S at high temperatures in the reducing atmospheres typical of the integrated gasification combined cycle (IGCC) processes.