Process Simulation and Techno-Economic Analysis of the Production of Sodium Methoxide

The worldwide increase in biodiesel production has created a major market for sodium methoxide, as a catalyst in the transesterification of vegetable oils. This work evaluates different methods for the manufacture of sodium methoxide, diluted in methanol. Alternative process designs are reviewed, and the most promising solutions are modeled in Aspen Plus, including their phase and chemical equilibria. Economic indicators are incorporated in a comparative profitability analysis that includes a risk evaluation with Monte Carlo simulations. The results show that the methods of manufacturing sodium methoxide from sodium metal (process II) and from sodium hydroxide (process III) are the most competitive alternatives, although each can be preferred in different contexts. Process III has a better chance of profitability (41%) than process II (34%), where the latter can be affected by higher raw-material costs and the first is more sensitive to variations in the utility and capital costs.