木粉焦CO_2和H_2O气化过程孔结构及反应性的变化

Changes of pore structure and reactivity during CO_2 and H_2O gasification of fir char

利用固定床实验装置,分别对木粉热解焦进行CO2和H2O气氛下的气化实验,并考察热解焦在经过部分气化反应后孔隙结构变化特点和气化反应特性。研究结果表明,木粉焦气化过程孔结构的变化规律与气化介质有关,CO2气化过程以产生微孔为主,孔径大部分在0.4nm～0.9nm;而H2O气化在反应初期以产生微孔为主,反应后期以扩孔为主;部分气化焦的反应性和比表面积关联结果显示,两者不具有简单相关性,反应性也受孔结构特性的影响。

The fir char gasification with CO2 and H2O were investigated with a fixed-bed apparatus,and the pore structure characteristics and the CO2 gasification reactivity of the partially gasified char were examined.The results of pore structure analysis indicate that during gasification the pore properties are affected by gasification agent,which means that during CO2 gasification mainly micropores are produced and the pore diameter is mainly in the range of 0.4nm^0.9nm,while during H2O gasification the micropores are produced at the beginning and then the mesopores are developed.The correlation between CO2 gasification reactivity and BET surface area shows that the char reactivity is affected not only by BET surface area but also by pore properties.