Extraction and characterization of Calophyllum inophyllum L. seed oil for biodiesel in the Philippines

Oil from Calophyllum inophyllum seeds from fruits obtained in La Union and Ilocos Sur [Philippines] were extracted and characterized to determine the potential as a feedstock for biodiesel production. The oil was extracted with non-polar solvents (i.e. petroleum ether, cyclohexane and hexane) and with the use of mechanical expellers (i.e. Yong-Jin electric expeller and manual hydraulic expeller). Petroleum ether extraction gave the highest oil yield of 77%, which was higher by 2% than previously reported (RISE, 2004). Extraction of fresh seeds using petroleum ether gave a high mean value of 48.95% while for dry seeds, the yield was 76.27%. The physico-chemical characteristics (i.e. specific gravity, saponification number, iodine number, free fatty acid number and peroxide value) of C. inophyllum seed oil from different sources and conditions were determined. In terms of fatty acid composition, C. inophyllum seed oil comprised of 39.20% oleic acid, 33.44% linoleic acid, 14.76% palmitic acid and 12.60% stearic acid. Among the treatments used in transesterification, 25% MeOH, 1% NaOH, a reaction temperature between 55-60 deg C and a reaction time of 90 minutes gave the highest ester yield of 84.22%. Further analyses of the C. inophyllum seed oil gave values of 43.84 for Kinematic Viscosity, 110 for Flash Point, 1a for Copper Strip Corrosion, 20 for Cloud Point, 2.44 for Carbon Residue, 76.24 for Acid Number and no detection (ND) for Free Glycerin. On the other hand, C. inophyllum fatty acid methyl ester yielded values of 45.84 for Kinematic Viscosity, 238 for Flash Point, 1a for Copper Strip Corrosion, 7 for Cloud Point, 0.73 for Carbon Residue, 24.12 for Acid Number and no detection for Free Glycerin. With transesterification the properties of C. inophyllum fatty acid methyl ester improved and met several of the PNS/DOE [Department of Energy] QS:002:2007 standards but further investigation to improve the other properties is needed.