Mathematical Modeling of High Pressure Tubular LDPE Copolymerization Reactors

Abstract

ABSTRACTIn this study a comprehensive mathematical model for high pressure tubular ethylene/vinyl acetate copolymerization reactors is developed. A fairly general reaction mechanism is employed to describe the complex free radical kinetics of copolymerization. Using the method of moments, a system of differential equations is derived to describe the conservation of total mass, energy, momentum and the development of molecular weight and compositional changes in a two-zone jacketed tubular reactor. In addition, the model includes a number of correlations describing the variation of physical, thermodynamic and transport properties of the variation of physical, thermodynamic and transport properties of the reaction mixture as a function of temperature, pressure, composition and molecular weight distribution of polymer. Numerical solution of the reactor model equations permits a realistic calculation of monomer and initiator concentrations, temperature and pressure profiles, number and weight average molecula...