多活性中心催化剂催化丙烯聚合的均匀球Monte-Carlo模型

Uniform ball Monte-Carlo model in propylene polymerization catalyzed by multi-active-site catalyst

采用均匀球模型描述颗粒内扩散阻力对聚合反应动力学的影响,催化剂颗粒内的聚合用MonteCarlo模型积分处理,建立了均匀球Monte-Carlo模型(UBMCM)。研究了多活性中心催化剂催化丙烯聚合中传质/传热限制对聚合反应动力学、催化剂活性、扩散效应、聚丙烯相对分子质量及其分布和粒径的影响,并将模拟结果与实验结果和传统Monte-Carlo模拟结果进行比较,得出UBMCM的相关系数达到0.994以上。丙烯聚合过程可分为3个阶段,即扩散控制、反应控制、稳态。UBMCM对丙烯聚合微观反应扩散体系的描述更为精确和深入。

The effects of intra-particle diffusion resistance on the polymerization kinetics were described by uniform ball model, and the intra-particle polymerization of the catalyst was treated with integral method by means of Monte-Carlo model, finally a uniform ball Monte-Carlo model （UBMCM） was built. The influences of the mass- and heat-transfer resistance in propylene polymerization catalyzed with multi-active-site catalysts on the polymerization dynamics, catalyst activity, physical diffusion effect, relative molecular mass and its distribution, and particle size of polypropylene were studied. The simulation data were compared with the experimental data and the simulation results from the traditional Monte-Carlo model. The correlation coefficient of UBMCM was more than 0.994. The propylene polymerization process can be divided into three stages, including diffusion control,reaction control and steady state. UBMCM was more accurate and deeper in describing the microcosmic reaction and diffusion system of propylene polymerization.