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.
- CO gasification
- Calcium catalyst
- Coal char
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Fuel Technology
- Energy Engineering and Power Technology