Synopsis: — The CO2 gasification behavior of Ca-loaded Yallourn brown coal char was investigated in the presence of H2 or CO with a thermal balance. The chemical form of Ca catalyst was in situ analyzed with a high temperature X-ray diffraction. In addition, oxygen containing-compounds on Ca-loaded char were evaluated with transient kinetics and temperature programmed desorption techniques. On the basis of these results, the mechanisms of H2 and CO inhibition on Ca-catalyzed carbon gasification were discussed. It was found that the presence of H2 suppresses the formation of surface oxygen containing-compounds as reaction intermediate. Therefore, H2 inhibition can be attributed mainly to the adsorption of H2 an Ca catalyst or on carbon surface in contact with Ca catalyst. As a result, the following catalytic processes are disturbed; the adsorption of CO2 on Ca catalyst, and the formation of CaCO3-C complexes. The temperature dependence of CO inhibition was quite different form the case of H2 inhibition, and this implies that the mechanism may be different in the two inhibition cases.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Energy Engineering and Power Technology