Hydrogen-Rich Syngas Production from Chemical Looping Gasification of Biomass Char with CaMn1-xFexO3

The chemical looping process is considered as a suitable way to produce hydrogen and syngas. CaMnO3, CaFeO3, and CaMn(1-x)FexO(3) (x = 0.2 and 0.4) perovskites were prepared via the sol gel method. Perovskites were characterized by X-ray diffraction and thermogravimetry and tested for hydrogen-rich syngas production from steam gasification of rice husk char in a fixed bed. The effect of four types of perovskites, temperature (700-900 degrees C), and steam/char mass ratio (3.6-8.4) on the hydrogen yield was investigated. The results showed that the H-2/CO ratio order is CaMn0.6Fe0.403 > CaMn0.8Fe0.2O3 > CaFeO3 > CaMnO3 at 750 C and steam/char mass ratio of 4.8. The chemical looping steam gasification process of rice husk char with perovskites was divided into three stages: (a) uncouple oxygen, (b) catalytic gasification, and (c) partial decomposition. On the basis of CaMn0.6Fe0.4O3 as a reaction material, the best operation conditions for the hydrogen rich syngas gasification process are 800 C and steam/char mass ratio of 7.2. The results also demonstrated that the higher steam/char mass ratio (8.4) carried out excessive heat based on computational fluid dynamics simulation. In addition, in comparison to the gasification reaction with CaMn0.6Fe0.4O3 at the optimum condition, the yield of CO is higher by the gasification reaction without CaMn0.6Fe0.4O3. CaMn0.6Fe0.4O3 easily selects catalysis to CO than H-2.