Dynamic modelling, simulation and control of isobutane dehydrogenation in a commercial Oleflex process considering catalyst deactivation

The main goals of this research are dynamic operability and controllability analysis of the commercial isobutane dehydrogenation Oleflex process to produce isobutene. The process consists of three series moving-bed radial flow reactors that inter-stage furnaces have placed between reactors. The dehydrogenation reactors are modelled based on the mass and energy conservation laws considering a two-dimensional heterogeneous model. Isobutane dehydrogenation, hydrogenolysis, propane dehydrogenation and coke formation reactions have been considered in the kinetic model. To prove the accuracy of the considered model and assumptions, the simulation results are compared with plant data. The open loop sensitivity analysis is carried out to evaluate dynamic characteristics and operability of the process. Also, the process controllability is investigated considering the conventional feedback PI and PID controllers. The simulation results show that the conventional PID controller is capable to reject load and track set point. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.