Biodiesel synthesis from Calophyllum inophyllum oil with different supercritical fluids

- FAMEs were synthesized from surahonne oil using four different supercritical fluids.
- Kinetic study for all the reactions was performed by varying time and temperature.
- Rate constants and activation energies of the reactions were obtained and discussed.

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 523 K to 673 K at 30 MPa with a molar ratio of 40:1 with times varying from 3 min to 3 h. Conversions higher than 80% were obtained within 30 min for oil reaction with MeOH and DMC at 623 K and conversions of 60% and 70% were obtained at 673 K with MeOAc and MTBE, respectively. Pseudo first order kinetics was used to obtain the rate constants and the activation energies followed the order: EMeOH < EDMC < EMeOAc < EMTBE.

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