Improving cold flow properties of palm fatty acid distillate biodiesel through vacuum distillation

Palm fatty acid distillate (PFAD), a by-product of refining process of crude palm oil can be used as a potential feedstock for biodiesel production. However, the application of palm oil-based biodiesel is often hinder by its poor cold flow properties (CFP). Biodiesel fuel with poor CFP may crystallize and result in clogging of fuel lines, filters and injectors that cause engine operability problems. For that, a vacuum distillation method was designed and its feasibility and efficiency in improving the CFP was examined. A total of 13.60wt% of total saturated fatty acid methyl esters were successfully removed from the PFAD biodiesel, resulting in the improvement of the cloud point (CP), cold filter plugging point (CFPP) and pour point (PP) of PFAD biodiesel from 20 °C, 19 °C, and 15 °C to 13 °C, 11 °C, and 9 °C, respectively. It is remarkable that the improved CFPP satisfied the requirements for grade C summer biodiesel for temperate climates in EN 14212 standard. Additionally, Sarin (U_FAME) empirical correlation was evaluated and it was found to have a good prediction of CFP for PFAD biodiesel, with lower than 2 °C deviation.