在空气气氛下采用热重分析法研究了固定床反应器中生物油水溶性组分的热解特性,利用Achar微分法和Coats-Redfern积分法相结合的方式进行动力学分析,计算了挥发和热分解的活化能、反应级数和动力学参数,确定了机理函数,并建立了热解动力学模型。结果表明,生物油水溶性组分的热解可分为3个阶段,即轻组分挥发段、重组分热解段和焦炭燃烧段,重组分热解段活化能较轻组分挥发段的活化能低很多。轻组分挥发段反应级数近似为一级,可采用一级反应模型来模拟,而重组分热解段反应级数近似为二级,可采用二级模型来表示。
The pyrolysis behaviors and kinetics of the water-soluble fraction of bio-oil in the oxygen atmosphere in a fixed bed reactor were studied by thermogravimetric (TG) analysis. Based on the experimental data, activation energies, reaction order and kinetic parameters were calculated by the Achar differential method and the Coats-Redfern integral method, the most probable mechanism functions were worked out, and therefore, thermal kinetic equations were finally obtained. The results showed that the pyrolysis of water-soluble fraction of bio-oil could be divided into three stages, that is, the evaporation of volatile fractions, the decomposition of heavy fractions and char combustion. The activation energies of volatilization were higher than those of decomposition stage. The first stage was expressed as first order reaction, which could be simulated by first order reaction model, and the second stage was expressed as second order reaction, which could be presented by the corresponding reaction model.