Catalytic Carbon Dioxide Gasification of Fly Ash derived from Fluidized Bed Gasification of Bituminous Coal with K2CO3.

The catalytic carbon dioxide gasification of fly ash produced during the coal gasification of fluidized bed was studied by thermal gravimetric analyzer using K₂CO₃ as catalyst. The effects of reaction temperature, K₂CO₃ loading method and K₂CO₃ loading amount on catalytic carbon dioxide gasification of fly ash were investigated. The dynamics of catalytic carbon dioxide gasification of fly ash was carried out by the shrinking core model and the dynamic parameters were calculated. The results show that the carbon conversion of the fly ash increases with the increase of reaction temperature. The difference between the carbon conversions of fly ash gasifying at adjacent temperatures decreases with the increase of gasification temperature. The carbon conversion of fly ash loaded K₂CO₃ increases with the increase of K₂CO₃ loading amount compared with the fly ash without catalyst. The higher the gasification temperature, the closer the gasification results when K₂CO₃ loading amount is 10 and 15%. The carbon conversions of fly ash with catalyst by impregnation method are higher than those loaded catalyst by mechanical mixing method at the same gasification temperature and gasifying for the same time. However, the high the temperature, the smaller the results difference between the fly ash loaded catalysts by different methods. The activation energy of the gasification reaction decreases with the increase of K₂CO₃ loading amount, and the activation energy of the samples with catalyst by mechanical mixing method is higher. [ABSTRACT FROM AUTHOR]