Optimal grade transitions in a gas phase polyethylene reactor

Abstract Using gas‐phase technology many grades of polyethylene can be produced in a single reactor. For a series of three polyethylene products, model‐based dynamic optimization is used to determine optimal grade changeover policies. Optimal manipulated variable profiles are determined for hydrogen and butene feed rates, reactor temperature setpoint, gas bleed flow, catalyst feed rate, and bed level setpoint. It is shown that large transitions …