UBC Theses and Dissertations
The simulation and optimization of a gasoline polymerization plant Friedman, Paul
A model of a chemical process plant with recycle streams was simulated on a digital computer using the CHESS executive program. This model was then optimized by means of an automatic optimization algorithm. The chemical plant chosen for the study was the gasoline polymerization unit of the Shellburn refinery, Shell Canada Limited, in Burnaby, B.C. Modifications were made to the following optimization techniques so that they could be utilized for the stated problem: Deflected Gradient-Created Response Surface, Pattern Search, Complex Method. It was found that the Modified Complex Method worked well and did not require an excessive amount of computer time. A strategy of model building was utilized to reduce the computer calculation time for a simulation to a minimum and at the same time create a model that would adequately represent the important aspects of plant operation. The results of the plant model simulation were within the range of reported plant data. In order to be able to develop a reasonable model of the polymerization reactor, an experimental kinetic study was made of the polymerization of mixed olefins to their dimerized products utilizing the U.O.P. solid phosphoric acid catalyst. A generalized rate expression was developed which fitted the experimental data very well; [See Thesis for Equation] where r = rate of reaction, mole olefin/hr/cc catalyst, k = reaction rate constant, cc olefin/hr/cc catalyst, x = fraction of olefins converted into product. Gas film resistance effects were not observed but pore diffusion resistance was present. The optimization results showed that higher total olefin conversions could be achieved if stricter temperature controls on the catalyst beds were maintained by means of the liquid propane quench.
Item Citations and Data