Utilization of calcium acetate and calcium magnesium acetate 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, Both sorbents have the ability to form highly cenospheric oxide particles on heating to high temperatures. The thin, porous walls of the cenospheres make these sorbents a very attractive material to sulfur removal due to their high utilization. Sulfur capture up to 90%, near the thermodynamic equilibrium, was achieved with dry powder injection of CA and CMA at furnace gas temperatures of about 1000 and 800 degrees C, respectively, a Ca/S molar ratio of 2, and a residence time of 0.8 s. Although more expensive, the sulfur capture effectiveness of these sorbents was superior to any natural calcium-based sorbent, Moreover, because of the high porosities exhibited by CA and CMA, the sulfided sorbents can be easily stabilized and converted into an inert material before disposal. 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.