Influence of intraparticle secondary heterogeneous reactions on the reaction enthalpy of wood pyrolysis
Influence of intraparticle secondary heterogeneous reactions on the reaction enthalpy of wood pyrolysis
复制标题
DOI：
10.1016/j.jaap.2015.08.019
复制
发表时间：
2015-11
影响因子：
6
通讯作者：
N. Zobel;A. Anca-Couce
中科院分区：
文献类型：
--
作者：
N. Zobel;A. Anca-Couce
尽管木材热解的技术相关性，这一转化步骤的反应焓仍然是一个有争议的问题。本文采用激光诱导荧光法和宏观热重法研究了直径为25 mm的干燥球形山毛榉木颗粒的缓慢热解过程。观察到，反应热与总荧光强度与转化率之比相关。在热解的放热状态下，该比值变化显著，而在吸热状态下则相对恒定。结合差示扫描量热法的结果和不同样品尺寸下的焦炭产率，本研究的结果可以解释为，当热解挥发物的非均相二次反应被促进时，焦炭的产生与多芳烃的产生同时增强，导致更放热的总反应热。
Despite the technical relevance of wood pyrolysis the reaction enthalpy of this conversion step remains a matter of controversy. In this work the slow pyrolysis of dry spherical beech wood particles with 25 mm diameter was investigated by means of Laser-Induced Fluorescence of the evolving volatiles together with macroscopic thermogravimetric analysis in a particle cell. It was observed that the reaction heat is correlated with the ratio of total fluorescence intensity versus conversion rate. In exothermic regimes of pyrolysis this ratio changes significantly, while it is relatively constant in endothermic regimes. Taking into account the results of differential scanning calorimetry and the char yields at different sample sizes the results of this study can be interpreted such that when heterogeneous secondary reactions of the pyrolysis volatiles are promoted, the production of char is enhanced together with the production of polyaromatic hydrocarbons, leading to a more exothermic global heat of reaction.