TY - JOUR ID - 1165 TI - Mathematical modeling the effect of catalyst initial shape and the crack pattern in olefin copolymerization JO - Polyolefins Journal JA - POJ LA - en SN - 2322-2212 AU - Nouri, Marzieh AU - Parvazinia, Mahmoud AU - Arabi, Hassan AU - Najafi, Mohsen AD - Iran Polymer and Petrochemical Institute (IPPI), P. O. Box 14975/112, Tehran, Iran AD - Qom University of Technology, P. O. Box 1519-37195, Qom, Iran Y1 - 2015 PY - 2015 VL - 2 IS - 2 SP - 121 EP - 133 KW - single particle KW - modelling KW - finite element method KW - polyolefin KW - copolymerization DO - 10.22063/poj.2015.1165 N2 - A two-dimensional (2D) single particle model for the copolymerization of propylene-ethylene with heterogeneous Ziegler-Natta catalyst is developed. The model accounts for the effects of the initial shape of the catalyst and carck/ pore patterns on the copolymer composition, polymerization rate and the average molecular weight properties. The spherical and oblate ellipsoidal shapes of catalyst particle and four different pattern distributions of cracks and pores in a growing particle are studied in this simulation. It is assumed that the diffusion coefficient of monomers in the cracks/pores is 10 times higher than the compact zone of the particle.In other word, the cracks are distinguished from parts with higher monomer diffusion coefficient.The dynamic 2D monomer diffusion-reaction equation is solved together with a two-site catalyst kinetic mechanism using the finite element method. Simulation results indicate that the initial shape of catalyst changes the average copolymer composition only in the early stage of polymerization, but the crack/pore patterns in the growing particle have a strong impact on the copolymer composition in the polymer particles due to the change ofmass transfer limitations. UR - http://poj.ippi.ac.ir/article_1165.html L1 - http://poj.ippi.ac.ir/article_1165_b2df56b622f083cfcc23024846130f45.pdf ER -