Modelagem e simulação de reatores de leito fluidizado para produção de polimeros




Polymerization processes represent an important sector of the chemical processing industry. Nowadays, polyethylene is, worldwide, the most consumed polymer, representing more than 40% of all thermoplastic consumption and production (1998). Since the end of the 80?s, polyethylene has been also produced in fluidized bed reactors by gas phase technology. But there is, still, the necessity to deepen the study this new technology, specially in the fluidized bed reactor modeling area. The main goal of this thesis is to develop a software capable to predict the hydrodynamic behavior of the fluidized bed reactor, and to characterize the polymer produced in the reactor, according to the operational conditions set for the reactor. A new phenomenological model was developed for the fluidized bed reactor used in polymer production. This model is capable to simulate the fluidized bed reactor behavior, previewing temperature and concentration gradients throughout the reactor height in both phases present in the reactor (bubble and emulsion phases); the polyethylene production and particle segregation in the reactor. Late models, found in the literature, only preview temperature and concentration gradients in the bubble phase and the polymer production. A mathematical model for the previewing of the physicochemical characteristics of polyethylene was also developed based on the method of moments, which has been expanded to support the presence of two phases and mass interchange between phases... Note: The complete abstract is available with the full electronic digital thesis or dissertations


polimeros polietileno reatores fluidizados

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