Optimization of a Computer Simulated Styrene Plant by Surface Response and Environmental Impact Evaluation

Abstract

Abstract Computer Aided Design of Chemical Process is now a well established eld in the design of new process as well as in the optimization, revamp and retrot of existing ones. The use of powerful process simulators available today allows the process engineer to simulate even an entire process, but the majority of process simulators have only classical unit operations. So, if the process has a non-classical unit operation it needs to be simulated using a suitable computer language and further to be linked to the simulator. In this paper we addressed the problem of including a new unit operation in a process simulator and how to use the virtual plant to optimize and to evaluate the environmental impact of a chemical process. We used the free chemical process simulator COCO to simulate two styrene process production plant. The firrst one uses as a reactor a conventional PFR that is available in the simulator. The second plant uses a membrane reactor that was simulated using the software Scilab that was embedded in COCO simulator by using the CAPE-OPEN protocol. Then, we used both virtual plants to develop meta-models of the processes by using experimental design and surface responses. These empirical models were used after to optimize the plants and the results shown that it is possible to increase the styrene productivity up to 27.32 kmol/h using a PFR reactor and up to 30.56 kmol/h using a membrane reactor. Finally, we calculated the Potential of Environmental Impact (PEI) for each process using the WAR algorithm and we shown that both processes have PEI very similar. Therefore, the route that uses membrane reactor has an advantage over the route that uses PFR reactor since it allows to obtain higher styrene productivities.