Flash point strictly corresponds to the methanol content and
viscosity correlates with un-reacted triglycerides. According to
Felizardo et al. [13], the flash point could decrease 50 C with
increasing only 0.5% of methanol content in the ester phase. The
flash point in this study was slightly lower than that from other research
[6,11] but much higher than biodiesel obtained from used
soybean oil and mixture frying oils [18]. The viscosity of the biodiesel
in this study was 4.89 mm2
/s, slightly lower than that from
other investigators [9,35]. Generally, the viscosity of the biodiesel
derived from WCO decreased 10 times compared to the original
WCO samples.