Abstract This study aims to investigate the intrinsic reactivity and structural evolution of chars that were originated from biomass, lignite and bituminous coal during steam gasification. A cornstalk, a lignite and a bituminous coal were selected to prepare chars by heating up to 1000 °C at a heating rate of 10 °C/min under inert atmosphere. The intrinsic reactivities of chars were then investigated using a fixed-bed reactor along with an on-line gas analysis system. The results showed that the determining factors that affected the intrinsic reactivities of the chars varied with the nature of the precursors. Besides the effect of surface area, the increase of Alkali and Alkaline Earth Metallic species (AAEMs) concentrations in cornstalk char played a key catalytic role in the intrinsic reactivity. The evolution of chemical structure was the main factor affecting the intrinsic reactivity of the lignite char. The relatively stable chemical structures and non-catalytic minerals in the bituminous char led to a constant intrinsic reactivity. The intrinsic reaction rates of the blends of lignite char and cornstalk char were slightly lower than that of the cornstalk char or lignite char, which suggests that their co-gasification caused inhibition on the intrinsic reaction rate. The intrinsic reaction rates of the blends of bituminous char and cornstalk char were higher than that of the bituminous char, and increased with the increasing ratio of cornstalk char. Therefore, a suitable strategy of blending biomass with specific rank coal is expected to bring significantly synergistic effect on the gasification reactivity and further improve the efficiency of co-gasification process.

中文翻译：

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生物质与不同等级煤焦气化过程中内在反应性和结构演化的比较研究

摘要 本研究旨在研究蒸汽气化过程中源自生物质、褐煤和烟煤的炭的内在反应性和结构演变。选择玉米秸秆、褐煤和烟煤在惰性气氛下以 10°C/min 的加热速率加热至 1000°C 来制备炭。然后使用固定床反应器和在线气体分析系统研究炭的固有反应性。结果表明，影响炭本征反应活性的决定因素随前驱体的性质而变化。除了表面积的影响外，玉米秸秆炭中碱和碱土金属物质 (AAEM) 浓度的增加对固有反应性起到了关键的催化作用。化学结构的演变是影响褐煤炭内在反应性的主要因素。沥青炭中相对稳定的化学结构和非催化矿物导致了恒定的内在反应性。褐煤炭和玉米秸秆炭共混物的固有反应速率略低于玉米秸秆炭或褐煤炭，这表明它们的共气化对固有反应速率造成了抑制。沥青炭与玉米杆炭共混物的固有反应速率高于沥青炭，并随着玉米杆炭比例的增加而增加。所以，