生物质热解的动力学特性研究

用综合热分析仪研究了氮气或二氧化碳作为载气的条件下,生物质(稻壳、玉米秸秆和木屑)热解的TG/DTG曲线的比较。依据TG曲线,将热解反应分为两个主导反应区,其拐点温度为Tf,并根据热重试验数据,利用改良的Coats-Redfern法和常用的46种机理函数,计算出生物质热分解反应的表观活化能、反应级数及频率因子。利用这些基础的动力学参数,计算出生物质热解的动力学特征值——反应速率常数k,活化熵△S≠,活化焓△H≠,活化Gibbs自由能△G≠,以及空间位阻因子P。用这些动力学特征值可以深入地了解反应过程和机理,预测生物质热解的反应速率以及难易程度。

Study on Kinetics of Pyrolysis of Biomass

The kinetics of pyrolysis of biomass was studied in nitrogen or carbon dioxide media. Based on TG curves, the pyrolysis process of the samples was divided into two dominant mass-loss event, inflexion temperature of which was determined as Tf. The values of active energy, frequency factor, was calculated by using date from thermogravimetry, improved Coats-Redfern method as well as 46 varieties common mechanism function. And the values of rate constant, activation entropy, activation enthalpy, activation Gibbs free energy as well as steric factor can be calculated by using the basic kinetic parameter.