海藻热解特性及动力学分析

采用热分析技术研究了两种海藻的热解特性。热解实验在流量为 100 mL/min 的氮气气氛下,加热终温为 700℃,升温速率为10、20、30、50和 80℃/min 的条件下完成。由失重和失重速率曲线分析表明:热解过程大致可以分为4个阶段:脱水、两个主要脱挥发分和残留物分解。根据热重实验数据,采用Popescu法确定海藻热解机理函数并且计算活化能和指前因子,结果表明Avrami-Erofeev方程可以用来描述海藻的主要挥发分脱除过程,热解机理为随机成核和随后生长机理。随着转化率的增加,活化能和指前因子也随着增加。说明转化率低,热解较容易发生。

Study on Pyrolysis Characteristics and Kinetics of Seaweed

The pyrolytic characteristics of two seaweeds were investigated by thermogravimetric analysis technique. The pyrolysis experiments were performed up to 700℃ at heating rates of 10、20、30、50 and 80℃/min in a dynamic nitrogen flow of 100 mL/min.The results showed four stages (dehydration, two main devolatilizations and residual decomposition) appeared in the pyrolysis process. Activation energies and pre-exponential factors were calculated by Popescu method. Experment results indicated that Avrami-Erofeev equation was suitable for describing the main devolatilization process of seaweed. Thermolysis mechanism was random nucleation and nuclei growth.With the increasing of conversion,activation energies and pre-exponential factors were also increased. This showed that pyrolysis took place easily when conversion rate was low.