Model based simulation and optimization of industrial tubular reactors for high pressure low density polyethylene production

Abstract

In this study, a comprehensive model of an industrial low-density polyethylene (LDPE) tubular reactor is presented. Parameter values used in this model are tuned using industrial data on the reactor temperature profile, the monomer conversion and the molecular characteristics at the end of the reactor. A good agreement between the model and industrial data is obtained. In the later section, a systematic procedure is developed to perform optimization study using the model that has been developed. The objective function used in the present study is the minimization of the reactor length. The reactor temperature is constrained to lie below a safe value and an equal end-point constraint is implemented in the outlet of each cooling zone. The results of this research show that, in principle, the overall length of LDPE’s can be minimized without disrupting the profile temperature through a proper manipulation of the control variable.In this study, a comprehensive model of an industrial low-density polyethylene (LDPE) tubular reactor is presented. Parameter values used in this model are tuned using industrial data on the reactor temperature profile, the monomer conversion and the molecular characteristics at the end of the reactor. A good agreement between the model and industrial data is obtained. In the later section, a systematic procedure is developed to perform optimization study using the model that has been developed. The objective function used in the present study is the minimization of the reactor length. The reactor temperature is constrained to lie below a safe value and an equal end-point constraint is implemented in the outlet of each cooling zone. The results of this research show that, in principle, the overall length of LDPE’s can be minimized without disrupting the profile temperature through a proper manipulation of the control variable.