High Pressure Polymerisation of Ethylene - Influence of extensions to Goto's kinetic model and data set on the prediction of process conditions and product properties

Abstract

In this report a conversion dependent termination model, developed by Buback, is investigated, and finally implemented in the kinetic model and data set derived by Goto. The report begins with an overview of the reactions in the free-radical mechanism of the high pressure ethylene polymerisation. Subsequently an evaluation is presented of the predictive performances of several kinetic models found in the literature. These models, which are of varying complexity, show a great discrepancy between predicted values and experimental values. This is especially the case for kp and kt, the rate coefficients of propagation and termination. The predicted kp√kt values on the other hand show a better consistency, which is not surprising as for predicting conversion and temperature only this ratio is of importance…