Investigation on the combustion behaviors of coke and biomass char in quasi-granule with CuO–CeO2 catalysts in iron ore sintering

Abstract

To thoroughly understand the combustion behaviors of coke and biomass char based on its physiochemical characteristics and distribution states in iron ore sintering, three types of single, composite and pellet quasi-granules of coke and biomass char were prepared carefully, catalytic potential of Cu0.1Ce0.9O2 to increase quasi-granule combustion efficiency defined by the extent of CO destruction in flue gas was investigated. The results showed that biomass char is combusted at relative low temperature in the range of 350–800 °C because it has higher volatiles and porosity, exhibiting high reactivity compared to coke which combusts from 650 °C to 1030 °C. Pellet type has an intrinsic high combustion efficiency due to its fine fuel size and the neighboring compounds effect. Single coarse type granules have a high CO concentration in flue gas and have the highest combustion efficiency improvement by Cu0.1Ce0.9O2 loading among all the types, which is mainly attributed to CO catalytic oxidation following Mars-van Krevelen path rather than the carbon oxidation. Through intentionally producing more coarse single type and composite type granules with 3 wt% Cu0.1Ce0.9O2 in granulation, substitution ratio of biomass for coke can be increased, leading to improved combustion efficiency of ~98% without deterioration of sintering performance.