半焦的多循环气化活性及微观结构分析

为了研究工业流化床气化条件下多循环过程中半焦的气化活性及微观结构变化规律,在快速反应固定床装置上,对三种不同煤阶的半焦进行了模拟多循环气化.通过残焦质量计算得到了循环次数对半焦碳转化率的影响,并利用孔隙分析仪和XRD分析仪考察了半焦的微观结构变化.结果表明,随循环次数的增加,低阶霍林河褐煤半焦的转化率增加,而神木烟煤和晋城无烟煤半焦的转化率降低.多循环过程中"冷淬"效应的存在使得半焦的BET比表面积和微孔比表面积随循环次数呈"山形"趋势变化,而石墨化结构与转化率的变化趋势一致,是决定碳转化率变化的决定性因素.

Multi-circulated gasification reactivity of coal char and its microstructure analysis

To investigate the variation in gasification reactivity and microstructure of char from the multi-circulation fluidized bed gasifier, 3 chars from different rank coals were gasified in a simulated multi-circulated reactor (rapid heating-up fixed bed). The carbon conversion was calculated from the weight of residues, and the structure was analyzed by pore and XRD analyzer. The results show that with the increase of cycle time, the carbon conversion of low rank HLH lignite char increases while that of SM bituminous and JC anthracite chars decrease. The evolutions of BET surface area and micropore area have a peak value with the circulate time. The variation of graphitization is similar with the carbon conversion, which can be considered as the key factor to determine the carbon conversion.