松木屑非等温热解动力学研究

通过热重分析法在不同升温速率(分别为10,30,50℃.min-1)下,采用非恒温热重法,以氩气为载气,流速60 mL.min-1,初温为30℃,加热终温为950℃.对粒径为80目的松木屑热裂解时的热失重行为进行了研究.结果表明:松木屑热解分为四个阶段,主要由预热干燥阶段、热解预热阶段、热分解阶段和热缩聚阶段4个阶段组成;生物质松木屑主反应阶段主要集中在180～600℃左右;随着升温速率的增大,松木屑原料热解的起始温度、热解最大速率所在的温度Tmax及热解终止温度都向高温处稍微移动.使用了Flynn-Wall-Ozawa积分法、Coats-Redfern积分法和Achar微分法对松木屑热解动力学参数进行求取,Flynn-Wall-Ozawa积分法得到的松木屑在热解过程中不同失重率下(0.1～0.80)的活化能都集中在142.35～220.12 kJ.mol-1范围内.按照Bagchi法对松木屑热裂解过程的最概然机理函数进行了推断.松木屑热裂解的最概然机理函数为15号机理函数随机成核和随后生长,反应级数n=2(Code:AE2),函数名称是Avrami-Erofeev方程.

Study on Non-isothermal Kinetics of Pine Sawdust Pyrolysis

Pine sawdust with particle size of 80 mesh pyrolysis weight loss behavior was studied by thermo gravimetric analysis （TG） at different heating rates （10, 30, 50 ℃·min-1） with argon as flow gas （flow rate 60 mL·min-1） from initial temperature 30 2℃ to final temperature 950 ℃. Results showed that pyrolysis process of the pine sawdust consists of your stages： preheating stage, drying stage, pyrolysis stage and thermal condensation stage. The reaction stage of biomass pine sawdust focuses on the temperature region 180-600 ℃. At the same time, the maximum pyrolysis temperature and final temperature shifted to higher region slightly with the increase of heating rate. The kinetics parameters of pine sawdust pyrolysis were obtained by Flynn-Wall-Ozawa integral method, Coats-Redfern integral method and Achar differential method. The activation energies of pine sawdust pyrolysis under different weight loss rates（0.1-0.80） centered in 142.35-220.12 kJ·mol-1 obtained by Flynn-Wall-Ozawa method. The most probable mechanism function of pine sawdust pyrolysis process was deduced with Bagchi method, and it was number 15 mechanism function： random nucleation and its subsequent growth with reaction rate n=2 （Code： AE2） with function name Avrami-Erofeev equation.