Multi-grade resin quality adaptive estimation for gas-phase polyethylene process

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 parameter updating law is deduced based on the predictive model of industrial polyethylene process resin quality. According to the off-line lab analytical data, an asymptotic tracking state observer design method is proposed to update the estimation of resin quality and predictive model parameter. The application results with the proposed method to an industrial plant verified the 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.