Catalytic chemical looping combustion of coal with iron-based oxygen carrier promoted by K₂CO₃

Effects of K₂CO₃ addition and inert supports on chemical looping combustion (CLC) of coal with iron-based oxygen carrier were investigated. The results indicate that the reduction of iron-based oxygen carrier by coal can be remarkably improved by the addition of K₂CO₃. This enhancement can be ascribed to the catalytic CO₂ gasification (rate-controlling step) by K₂CO₃ which migrates from oxygen carrier to coal particles. The sintering of iron-based oxygen carrier is promoted by K₂CO₃ due to its low melting temperature and the intensified redox reaction after K₂CO₃ addition. The inert support has no significant effect on the reactivity between coal and oxygen carrier, which could be due to the inert support do not affect the rate-limiting step. The catalytic activity can be observed during several redox cycles. However, there is a decreasing tendency of activity due to the loss and deactivation of catalyst.