摘要
利用TG-MS联用仪研究了煤焦油热裂解时的热失重特性和气相产物的逸出规律,应用双外推法推断了煤焦油裂解反应机理,采用Costs-Redfern积分法和Flynn-Wall-Ozawa积分法对数据进行了拟合计算,求得了煤焦油两阶段失重反应的机理函数及动力学参数.结果表明,煤焦油裂解主要有两个失重阶段:第一阶段是煤焦油分子脱水后的缩聚反应过程,此过程主要受随机成核机理的控制,属于旧物相消失新物相生成的成核阶段,主要产物为小分子气体和大分子冷凝焦油,活化能为162 kJ/mol.第二阶段是焦油冷凝大分子再次裂解的过程,此过程受三维扩散机理的控制,反映了气相产物相互传输的机理,是核的生长和扩散阶段,此阶段主要产物为H2和CO,活化能为76.68 kJ/mol.
Simultaneous thermogravimetry-mass spectrometry（TG-MS） was used to investigate the pyrolysis behavior of coal tar and the instantaneous evolution characteristics of gaseous products,and the pyroletic reaction mechanism of coal tar was inferred by the double extrapolated method.Data processing/fitting was conducted introducing the Costs-Redfern and the Flynn-Wall-Ozawa integration methods,thus giving the two-stage reaction mechanism function of weightlessness and kinetic parameters.The results showed that mainly there are two weight loss stages during coal tar pyrolysis.The first one is a polycondensation process of organic reaction after dehydration,which is mainly affected by the random nucleation mechanism and,as a result,the old phase disappears with new phase generated for nucleation.In the stage the main products are micromolecular gases and macromolecular condensed tar,and the activation energy is 162 kJ/mol.In the second stage the pyrolysis occurs once again for the macromolecules of condensed tar under the control of three-dimensional diffusion mechanism,which reflects the mutual transfer mechanism between gaseous products.Moreover,in the second stage the nuclei are growing and diffusing,where the products are mainly the hydrogen and carbon monoxide with an activation energy 76.68 kJ/mol.
出处
《东北大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2010年第4期550-554,共5页
Journal of Northeastern University(Natural Science)
基金
国家高技术研究发展计划项目(2009AA05Z215)
中央高校基本科研业务费资助项目(N090402010)
关键词
煤焦油
热裂解
双外推法
机理模型
coal tar
pyrolysis
double extrapolated method
mechanism model
