Catalytic steam gasification of Mengdong coal in the presence of iron ore for hydrogen-rich gas production

Abstract

Hydrogen-rich gas production from catalytic steam gasification of coal was investigated in the presence of iron ore in a vertical fixed bed reactor. The addition of iron ore significantly promoted the H2 yields. The effects of operation parameters (upper zone temperature, lower zone temperature, steam concentration, and iron to coal ratio) on the yield of selected gaseous products (H2 and CO) during catalytic steam gasification, were studied using Taguchi method. The results of signal-to-noise ratio indicated that steam concentration and iron to coal ratio were the most important parameters in determining the yield of H2 and CO, respectively. Semi-quantification X-ray diffraction analysis of iron ores indicated that increase in steam concentration intensified the oxidization of low valence iron compounds to Fe3O4. In addition, formation of Fe3O4 was also favored with increasing reaction temperatures (600 °C–900 °C). However, the formation of Fe3O4 was inhibited at higher reaction temperature (1000 °C) due to the destruction of porous structures of the iron ore.