Simulation of a Hybrid Reactive Extraction Unit. Biodiesel Synthesis

Biodiesel is an alternative for existing diesel vehicles. This work focuses on the rigorous simulation of a hybrid reactive liquid-liquid equilibrium extraction as a novel alternative process for the production of biodiesel. In this study, the alkaline transesterification of vegetable oils, methyl oleate (triolein) being the major component, with methanol as short chain alcohol is considered. This process involves two zones in the extractive column: one reactive-extractive zone and another only extractive. The reactants are countercurrent thereby improving the separation and the formation of products, glycerin and methyl oleate, allowing a high purity of these. Part of the glycerol obtained from the reactive section is used as extractive agent in the extractive section. The simulation proves that reactive extraction achieves saving far more raw materials than other processes. It eliminates the need to use a large excess of methanol to shift the reaction equilibrium to the right and produce methyl esters (FAME) as a main product. The proposed process has been compared to other currently used processes.