Steady-State and Dynamic Modeling of the Solution Polyethylene Process Based on Rigorous PC-SAFT Equation of State

This work aims to perform steady-state and dynamic modeling of an industrial solution polyethylene process. The phase behaviors in reactors under various conditions were predicted by the reparametrized perturbed-chain statistical associating fluid theory equation of state (PC-SAFT EOS), and the broad molecular-weight distribution of the polymers was calculated by the traditional Ziegler–Natta polymerization kinetics. A cascade continuous stirred tank reactors model was adopted to simulate the real polymerization reactor, and the simulation results indicate that the accuracy of the simulated temperature distribution in industrial reactors can be improved by considering the effect of back-mixing. The effects of process variables on the performance at plant scale were investigated by the steady-state model. Furthermore, the dynamic model was applied to capture the dynamic behaviors during grade-transition procedures.