Date of Award
The following study was conducted to assess the economic and process feasibility of a dimethyl ether (DME) production process. A portion of the methanol produced by an existing facility would be used to produce DME through a dehydration reaction. DME production is being considered as a means to compensate for lost methanol revenue, as methanol prices have recently decreased and an excess supply is present on the open market.
The first milestone in the study was the construction of a working process model within AVEVA Process Simulation. This steady-state process model would provide information essential to further design and optimization efforts, and serve as a starting point from which process optimizations could be considered.
An additional process model was created, using the “base-case” as a template, in which a distillation column was economically optimized. In this optimized column model, the size and configuration of the distillation column were adjusted to minimize the Equivalent Annual Operating Cost (EAOC) of the unit.
Because the DME process was proposed as a temporary solution, it was necessary to cooperate with a Toller in renting process equipment. The Toller had a limited inventory, so availability was a consideration in the choosing of DME process equipment.
Upon delivering the optimized column model to management, the team was provided with a slightly adjusted process model. This model would serve as the basis for the creation of a number of new models, using various equipment sizes from the Toller’s inventory. An optimal set of equipment was subsequently chosen using the information provided by these models.
The team performed an economics analysis of the project using process information from the recommended optimized process model and cost estimation methods for chemical processes. While a number of estimates were made in this analysis, the economic metrics ultimately indicated that this project would be economically viable, with a net present value of $11.5 million and a conventional payback period of 2.6 years.
Process feasibility was also assessed in this study. It was concluded that the proposed process is feasible, as the three areas of concern identified were deemed acceptable in the presence of sufficient safety measures and process controls. This determination was made using a process conditions matrix and generalized experience within the chemical industry.
It was recommended that the company move forward with the dimethyl ether plant immediately. Additional recommendations to improve process economics were also made, which are discussed below.
Gaouette, Nicholas, "AVEVA Competition 2021: Dimethyl Ether Production Process" (2021). Honors Theses. 1755.
Available for download on Thursday, April 28, 2022