Study on CO2 Gasification Reaction during the Combustion of Pulverized Coal Char Particle

Although much research on the effect of CO2 gasification on char combustion has been reported, few studies give clear information on the proportion of carbon consumed by the gasification and oxidation respectively. In this work, a drop-tube furnace is used to study the combustion of Huangling bituminous coal char in different oxygen and carbon dioxide concentrations at different residence times. It is found that with increasing CO2 content the carbon conversion ratio decreases first and then goes up in both oxygen content of 21 and 36 vol.%. There always exists a minimal point around CO2 content of 8-15 vol.% along with increased residence time during pulverized coal char combustion. Meanwhile, a preliminary formula is proposed to calculate the overall carbon conversion ratio of char and the proportion of carbon consumed by the gasification and oxidation respectively. (C) 2017 The Authors. Published by Elsevier Ltd.