Date of Award
The company that the engineering team works for is facing a contract loss with one of its customers of methanol. To avoid economic losses, a process has been proposed for converting the unused methanol to dimethyl ether (DME) through a dehydration reaction. After a preliminary simulation of the base case and optimization of the distillation column, an Equivalent Annual Operating Cost (EAOC) of $140,000 was calculated for the column. The EAOC was the sum of the annualized capital investment and the annual operating cost. Determining the process to be worth pursuing, a Toller was brought in to provide rental equipment needed for production. Using the available equipment from the Toller, the team performed a new optimization, this time of the entire process, by changing the process conditions from the base case. Optimization was streamlined by creating equations to verify equipment viability and display rental costs, and by identifying constraints evident from comparing the available equipment to constants in the process. The best equipment set decided upon, with an overall yearly cost of $689,000, utilized the smallest reactor and distillation column by strategically sizing the condenser, reboiler, and other heat exchangers. The overall yearly cost was the sum of all yearly rental and utility costs. To improve process safety, the team recommended abiding by Process Safety Management (PSM) guidelines, placing a deluge system on the reactor, placing conservation valves on all tanks, and piping pressure relief valve outlets to catch tanks. To decrease the plant’s environmental impact, the team recommended implementing heat integration networks and targeting a higher conversion of methanol. By lowering feed purity to investigate the effect on process economics, the team found that the profit decreased by only 3% when purity was decreased by 1.8%. The process was found to have a profit margin of $6.14 million per year with the best equipment set in use. This was determined by subtracting the raw material cost ($6.9 million) and the overall yearly cost from the revenue generated ($13.7 million). The team therefore recommended progressing to the next phase of the project.
Mathwig, Thomas, "Design, Analysis, and Optimization of a Process to Produce Dimethyl Ether from Methanol" (2021). Honors Theses. 1859.
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