挥发分-半焦交互作用是生物质热化学利用过程普遍存在的现象。为了解析交互反应对生物质热解半焦特性的影响,利用一阶固定床/流化床反应器及快速热裂解仪进行实验。针对挥发分-半焦交互反应,对碱金属和碱土金属(AAEM)元素的析出特性展开了研究,同时分析了交互反应对生物质热解半焦反应活性的影响。结果表明在700-900℃范围内,交互反应的存在使得热解成焦率较无交互反应下有所提高。热解过程中交互反应导致了单价K元素析出量增加,对二价Ca/Mg元素的析出影响较小。挥发分-半焦交互反应的存在使得半焦反应活性对温度的敏感度降低,随温度的升高其反应速率的下降幅度变缓。
The volatile-char interaction is a common phenomenon during the biomass pyrolysis. In order to study the effect of volatile-char interaction on pyrolysis biochar, the one-stage fluided bed/fixed bed reactor and Py were used in the experiment. The AAEM analysis was carried out with/without the volatile-char interaction. The effect of volatile-char interaction on pyrolysis biochar reactivity was analyzed. The results showed that with increasing pyrolysis temperature from 700℃ to 900℃, the pyrolysis char yield was increased due to the volatile-char interaction as compared with the weak interaction. In the process of pyrolysis, the increase of precipitation of K was caused by the volatile-char interaction. The migration and precipitation characteristics of Ca/Mg elements did not have a significant change. The biochar sensitivity to temperature was reduced by volatile-char interaction and the reactivity of biochar was decreased with increasing temperature.