孜然粉热分析反应动力学研究

Kinetics Study on Thermal Analysis of Cumin Powder

采用热重分析法(TG)对孜然粉在高纯氩气中的热解反应动力学进行了研究,结果表明:孜然粉在高纯氩气中热解过程的主反应阶段为157~380℃,随升温速率增加,主反应区间略有增加。Flynn-Wall-Ozawa法和KAS法可算出孜然粉在主反应区的活化能分别为157~162 k J·mol^(-1)和156~161 k J·mol^(-1)。根据Coats-Redfern方程可求算出孜然粉热分析动力学三因子,从而得出孜然粉热解过程遵循三维扩散模型,并给出机理函数的微分形式和积分形式。

Pyrolysis reaction kinetics of cumin powder was studied by thermogravimetric analysis（ TG） under high purity argon atmosphere. The results showed that the major reaction stage of the pyrolysis process of cumin powder in high purity argon atmosphere was ranged within 157 - 380 ℃,and the range of major reaction process was expanded with the increase of heating rate. The range of activation energies of cumin powder were 157-162kJ·mol^-1 and 156- 161kJ·mol^-1 by Flynn-Wall-Ozawa method and KAS method,respectively. According to the Coats-Redfern equation,three factors of the cumin powder pyrolysis can be calculated. As a result,the pyrolysis process of cumin powder was followed by the three-dimensional diffusion model,and the differential form and integral form of the mechanism function were given.