Process Analysis of Biodiesel Synthesis in Supercritical Methanol

The objective of this research is to design, simulate, integrate, and optimize a biodiesel production facility which uses supercritical methanol (SCMeOH) for the transesterification of vegetable oils. First, a process simulation model was developed using the computer-aided software ASPEN Plus. Conventional and non-conventional model compounds were employed to represent the chemical species involved in the process. A base-case simulation was conducted. Next, flowsheet variations were created to explore several production schemes. Sensitivity analysis was used to determine the impact of varying design and operating conditions on the process performance. Mass and energy integration were used to reduce the consumption of natural resources within the process and to mitigate much of the environmental impact of the facility. Finally, relative cost estimation based upon energy and mass consumption was used to compare the proposed processes. The results of this analysis indicate that a process utilizing SCMeOH and a propane co-solvent yields annual savings of 23% on utilities, 20% on operating costs, and 4% on raw material costs when compared to the established alkali-catalyzed process for the production of biodiesel.