Control of Polymer Quality in Gas Phase Polyethylene Reactors Using Feed Flow Rates

Abstract

Abstract-Nonlinear model predictive control algorithm (NLMPC) is used for the on-line control of polymer molecular weight distribution. The control of chain-length distribution is achieved by selecting a collection of points in the distribution and using it as set points for the control algorithm. NLMLPC is implemented in online fashion to manipulate both the hydrogen and monomer feed rates. The simulation investigated the control algorithm performance for set point tracking conditions. The results demonstrate that the control algorithm can regulate the entire molecular weight distribution with high computational efficiency and minimum steady state error even in the presence of modeling errors.