Abstract:

Due to the lack of on-line analyzer, resin quality such as melt index and density can not be on-line measured and controlled in the industrial polyethylene process. In this paper, a predictive model of resin quality was deduced for industrial polyethylene process based on the kinetics of ethylene polymerization. According to the approximation error upper bound of the deduced predictive model, based on the multiple fading extended Kalman filter a method of design the suboptimal strong tracking filter was proposed to update the estimation of resin quality based on the off-line lab analytical data. The application of the proposed method to an industrial Unipol licensed linear low-density polyethylene process verified its feasibility and effectiveness. With the proposed method, resin quality of industrial polyethylene process can be on-line estimated and on-line resin quality advanced control can be achieved.