Catalytic Carbon Dioxide Gasification Of Fly Ash From Fluidized Bed Gasifier

In this study,long-flame coal and fly ash collected in bag filter of circulating fluidized bed gasifier were used as raw materials,and then the effects of catalyst type,catalyst loading mode,catalyst loading amount and gasification temperature on carbon dioxide catalytic gasification of long-flame coal and fly ash from fluidized bed gasification were analyzed by thermogravimetric analyzer.The kinetic model of CO₂catalytic gasification of fly ash from fluidized bed gasification was studied by homogeneous model and nucleation model,then the kinetic parameters were calculated.The main conclusions of this paper were as follow:（1）Both K₂CO₃and Na₂CO₃in alkali metals have good catalytic activity in fluidized bed gasification of fly ash and long flame coal char,which can increase the gasification reaction rate and reduce the final temperature of gasification reaction.Ca O can even inhibit the gasification of basic oxides.The order of catalytic activity of the three catalysts is K₂CO₃>Na₂CO₃>Ca O.（2）Gasification reaction temperature,catalyst loading and loading method have great influence on the gasification reaction characteristics of fly ash from fluidized bed gasification.The higher the gasification reaction temperature is,the greater the carbon conversion rate of fly ash is,and the shorter the reaction time is;the higher the catalyst content is,the greater the carbon conversion rate and the shorter the reaction time are,at lower gasification temperature,the impregnation method has better catalytic gasification effect.There is no obvious difference between the two loading methods after increasing the gasification temperature.（3）The fitting effect of the shrinking core model is better than that of the homogeneous model,and the correlation coefficient is higher than that of the homogeneous model.