Polymer properties on-line estimation for an industrial polyethylene process based on suboptimal strong tracking filter

A major difficulty affecting the control of product quality in industrial polymerization reactors is the lack of suitable on-line polymer property measurements. In this article, a predictive model of polymer properties is deduced for industrial polyethylene process based on the kinetics of ethylene polymerization. According to the approximation error upper bound of the deduced predictive model, a method of design the suboptimal strong tracking filter is proposed to update the estimation of polymer properties based on the off-line lab analysis data. The application result of the proposed method to the industrial UNIPOL licensed linear low-density polyethylene process has verified its feasibility and effectiveness. With the proposed method, polymer properties of industrial polyethylene process can be on-line estimated and make it possible for achieving the advanced on-line product quality control.