Dynamic simulation and optimisation of tubular polymerisation reactors in gPROMS

In this paper a dynamic model of the high-pressure polymerisation of ethyle ne in tubular reactors is introduced and a dynamic optimisation problem is formulated for studying start-up strategies. The optimisation objectives pr oposed are to maximise outlet conversion and optimise the time necessary fo r it's stabilisation while keeping product molecular properties between com mercial ranges. Results are shown giving the time responses for temperature , number-average molecular weight and conversion along the reactor axial di stance, which were obtained using different control variable profiles. Impr oving in reactor productivity is achieved. The interface gOPT of the gPROMS simulator was used to resolve the optimisation problem and to perform the simulations. (C) 2001 Elsevier Science Ltd. All rights reserved.