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A method for quantitative evaluation of kinetic constants in Ziegler–Natta and metallocene olefin polymerizations is presented. The method comprises some fundamental steps, which include the initial design of a statistical experimental plan, the execution of the designed experiments, the development of simple mathematical models to describe the polymerization, and the estimation of kinetic parameters from available rate, gel permeation chromatography, and NMR data. The method is applied to the slurry propylene polymerization, using a conventional first generation Ziegler–Natta catalyst, in a lab‐scale polymerization reactor. It is shown that the proposed method allows the successful interpretation of experimental olefin polymerization data and the quantitative evaluation of kinetic constants, which can be inserted into a process simulator to provide an accurate picture of actual industrial plant behavior. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2076–2108, 2001

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A method for the quantitative evaluation of kinetic constants in Ziegler–Natta and metallocene olefin homopolymerizations presented previously (V. Matos, A. G. M. Neto, J. C. Pinto, J. Appl. Polym. Sci. 2001, 79, 2076; V. Matos, A. G. M. Neto, M. Nele, J. C. Pinto, J. Appl. Polym. Sci. 2002, 86, 3226) is extended to allow for estimation of model parameters in copolymerization reactions. The method is used to estimate kinetic parameters of ethylene/propylene copolymerization during the synthesis of high impact poly(propylene) in a train of cascade reactors. Process models were developed to describe the reaction rate profile, reactor solubles, molecular weight distribution of the total polymer, xylene solubles, and insoluble polymer. The process models and the estimated parameters were inserted into a process simulator that successfully described the industrial process.

In this work, a comprehensive model is developed for the ethylene/1-butene copolymerization in an industrial slurry polymerization reactor for linear low-density polyethylene synthesis. The model is able to describe the dynamic evolution of the molecular weight averages, comonomer content, particle size averages, melt index, and density of the final polymer resin and extends modeling results available in the open literature. A new modeling approach is used to describe the evolution of particle sizes, which is based on the definition of a joint distribution of mass and catalyst concentration of solid polymer particles. It is shown that the model successfully describes the operation of an industrial slurry polymerization reactor. For this reason, the model is used to analyze how sensitive the final polymer properties are to variations of the feed conditions and to development of segregated mixing zones inside the reactor vessel. It is shown that the ethylene feed flow rate is the most influential process variable and that the existence of very small segregated reactor zones can lead to very serious operation problems, such as particle agglomeration.