Biodiesel synthesis from Calophyllum inophyllum oil with different supercritical fluids.

Biodiesel or fatty acid methyl esters (FAMEs) is primarily synthesized using edible vegetable oils and methanol with a catalyst. However, in the present study, FAMEs were synthesized from a non-edible oil (Calophyllum inophyllum also called as sura honne, Punnagam, Alexandrian Laurel) in different supercritical fluids: methanol (MeOH), methyl tert-butyl ether (MTBE), methyl acetate (MeOAc) and dimethyl carbonate (DMC) non-catalytically. Reactions were performed from 523K to 673K at 30MPa with a molar ratio of 40:1 with times varying from 3min to 3h. Conversions higher than 80% were obtained within 30min for oil reaction with MeOH and DMC at 623K and conversions of 60% and 70% were obtained at 673K with MeOAc and MTBE, respectively. Pseudo first order kinetics was used to obtain the rate constants and the activation energies followed the order: E<E<E<E.