Date of Award
Beginning in the fall semester, I was a member of a team that simulated and optimized a styrene production process in Microsoft Excel. After the base case was simulated, parametric and topological optimizations were completed. The optimizations had to be completed in a certain order that starts with the reactor section, then move to the separation section, heat recovery section, heating/cooling utilities section, and ends with the water and effluent treatment section. During this project, the first three sections were explored. Optimizing the base case was completed by making these changes to see how they increased the net present value of the plant. After completing the beginning of the project in the fall semester, the next semester, the additional project was assigned. Another topological optimization was to be completed by using a fluidized bed reactor instead of an isothermal or adiabatic reactor, which were the base case and optimized case respectively. Because of the differences in feeds between the isothermal and adiabatic case, a fluidized bed reactor was simulated using both feeds. For this set of optimizations, the equivalent annual operating cost (EAOC) of each type of reactor was calculated. The EAOC is a function of capital cost and the yearly operating cost. The yearly operating cost is the yearly utility cost of the fired heater. The capital cost is different per reactor. It is the price of an equivalent heat exchanger for the isothermal, equivalent vessel for the adiabatic, and a given function for the fluidized bed. The function for the fluidized bed includes the heat transfer surface area. The part of the surface area that could be changed was the number of pipes. Since the equivalent annual operating cost is a cost, optimizations would decrease it. The only way to decrease the surface area is to decrease the number of tubes. Minimizing the EAOC would decrease the number of tubes to zero which is not possible so the optimizations for this part of the project were not possible. The EAOC was, after comparing reactors, lower for the fluidized bed. It is because there are 10 reactors of the other reactors versus 2 fluidized bed reactors.
Morgan-Harris, S Arizona, "Equivalent Annual Operating Cost of Reactors in A Discrete Optimized Styrene Process" (2019). Honors Theses. 1071.