Energy Sources Part A-recovery Utilization and Environmental Effects, Vol.38, No.20, 2985-2993, 2016
Regulation of chemical properties of ash and kinetic model construction of Lu'an coal gasification
The objective of this study was to enhance the suitability of Lu'an coal for gasification in large entrained-flow gasifiers currently used by the Lu'an Group Mining Company in its 1.8 million ton per annum coal-based oil synthesis demonstration project. The effect of coal blending and flux addition on the ash fusion temperature (AFT) and gasification reactivity was investigated. CaO, Fe2O3, and MgO decreased the AFT of Lu'an coal by 150 degrees C, 73 degrees C, and 68 degrees C, respectively, by a flux addition of up to 7%. Within the range of the experimental investigation, the AFT of Lu'an coal decreased by 3 degrees C for each 1% of Shenmu coal addition. The gradual reduction of mullite and the formation of fayalite and hessonite in blended coal ash decreased the AFT. The addition of a fluxing agent significantly increased the reaction activity of the char, with Fe2O3 exhibiting the largest catalytic effect on char gasification. Blending with Shenmu char significantly increased the gasification reactivity. The random pore model best describes the gasification process of Lu'an char, and a kinetic equation for the process was developed on the basis of this model.
Keywords:Ash fusion temperature;chemical properties of ash;fluxing agent;gasification kinetics;random pore model