RIGOROUS MODELING OF A HIGH PRESSURE ETHYLENE-VINYL ACETATE (EVA) COPOLYMERIZATION AUTOCLAVE REACTOR

Polyethylene (PE) is one of the most widely used polymers in chemical industry. In all the PE processes, high-pressure autoclave process is generally considered as the most profitable segment of the polyethylene business worldwide in recent years. Depending on different grades of the product, reactor zone temperatures in this autoclave process can be in the range 150-230°C and pressure in the range of 1500-2000kg/cm2. In this paper, rigorous dynamic model of an industrial ethylene and vinyl acetate (EVA) copolymerization reactor will be established. Industrial operating condition data of seven product grades with melt index ranging from ones to over four hundred will be used as fitted or test data to obtain the key kinetic parameters in the model. The predicted outputs of melt index, vinyl acetate wt. % in polymer, and polymer production rate will be compared to plant data.