【摘要】 为了了解半纤维素的快速热解机理,研究了反应温度和载气体积流量对半纤维量的热解影响.采用木聚糖作为模化物,在红外辐射加热反应器进行快速热解试验研究.试验结果表明,木聚糖热解生成的焦油产率随温度升高而增加,达到最大值后随着温度的继续升高,焦油发生二次裂解使产率降低;焦炭产焦随着温度的升高而降低,最后趋近稳定值;气体产物主要有H2、CO、CO2、CH4以及CnHm,其产率随温度升高而增加.随着载气体积流量的降低,木聚糖热解产生的挥发分在高温区的停留时间增加,导致挥发分二次裂解加剧而使焦油产率降低,同时气体和焦碳产率相应增加.更多还原

【Abstract】 To deal with the rapid pyrolysis mechanism of hemicellulose,the effects of reacting temperature and carrier gas flow on hemicellulose pyrolysis was studied.The rapid pyrolysis of xylan as the model compound of hemicellulose was researched on heat radiation reactor.The results show that the yield of xylan pyrolysis tar product increases with rising reacting temperature,but decreases with rising temperature after approaching a maximum value caused by the secondary decomposition of tar.The char yield decreases with rising temperature and finally appoach a constant value.Incondensable gaseous products yields of H₂,CO,CO₂,CH₄ and C_n H_m increase with rising temperature.With reducing carrier gas flow long vapour residence time causes secondary cracking,and the tar yield decreases but the gas and char yields increase.更多还原