Acid-Catalyzed Transesterification of Canola Oil to Biodiesel under Single- and Two-Phase Reaction Conditions

Experiments were performed at ambient temperature to investigate the effects of mass transfer during the transesterification reaction of canola oil with methanol (MeOH) to form fatty acid methyl esters using a sulfuric acid (H 2 SO 4 ) catalyst at a MeOH/oil molar ratio of 6:1. Experiments at ambient conditions resulted in reaction rates that were slow enough to permit the effects of mass transfer on the transesterification reaction to become more evident than at higher temperatures. For the two-phase experiments, it was postulated that the reaction occurred at the interface between the phases where the triglycerides (TG), MeOH, and H 2 SO 4 were in contact with one another. The influence of mass transfer was investigated by (a) comparing a mixed versus quiescent two-phase reaction and (b) changing a two-phase reaction to a single-phase reaction through the addition of a solvent, tetrahydrofuran. The experiments revealed the presence of an induction period prior to the initiation of the reaction, and some of the factors influencing the induction period were identified.