(374b) Supercritical CO2 in Production of Biodiesel from Algae: Multi-Scale Processing

In recent years, Floudas and coworkers focused on multi-scale energy systems. In the 1990’s, McDonald and Floudas applied tangent-plane distance analysis to locate the phase distribution at the global minimum of the Gibbs free energy. Proper solution of the latter problem at the reactor scale can have a significant impact on the optimum design of commercial-scale processes to generate biodiesel fuel from algae cells. In recent work, we have been exploring the combined extraction of triglyceride oil from nannochloropsis salina algae cells and its transesterification to biodiesel using supercritical CO2 and methanol. Reaction rates are increased as the methanol solubility in triglyceride oil increases. In this paper, the importance of locating the global minimum in the tangent-plane distance function (i.e., identifying phase instability when it occurs) is demonstrated when producing biodiesel from algae cells.