Tailoring the Complete Molecular Weight Distribution in the High-pressure Polymerization of Ethylene in Tubular Reactors

MARIANO ASTEASUAIN; ADRIANA BRANDOLIN

Los Cocos

Congreso; III Argentine Chilean Polymer Symposium (ARCHIPOL'05); 2005

Universad Nacional de Córdoba

High-pressure polymerization of ethylene to produce low-density polyethylene in a  tubular reactor is a widely used industrial process. It is carried out under rigorous operating conditions, and consequently a mathematical model is an attractive tool to study safely and economically the influence of the different design and operative variables on the production performance and product quality. Finding the process conditions that will produce a tailored molecular weight distribution (MWD) is a very useful application of a mathematical model, because a number of processing and end-use properties of the polymer are strongly dependent on its MWD. Several methods have been proposed to predict the complete MWD in different systems. However, applications for tailoring the MWD are not frequent. In the particular case of the high-pressure ethylene polymerization in tubular reactors, there are few works dealing with the calculation of the complete MWD, but none of them attempted to tailor this property. In this work, we present a rigorous steady-state model of the high-pressure ethylene polymerization in a tubular reactor that is able to calculate the complete MWD along the axial distance, and its application in tailoring  the polymer MWD.