Emissions of greenhouse gases are of interest because of the
likelihood that they contribute to global warming. This study
showed that the production (including transport) and use of
UCOME generates 0.86 and 1.49 kg CO2-eq per 100 km transportation
in a light duty diesel vehicle respectively whereas
conventional diesel generates 5.21 and 27.36 kg CO2-eq respectively.
Considering the life cycle GHG emissions of diesel (about
3.41 kg CO2-eq/l) are substantially higher than UCOME (about
0.23 kg CO2-eq/l), a fuel switch from diesel fuel to UCOME in
transportation will contribute greatly to the reduction of GHG
(93%). Therefore, around 45,945 ton CO2-eq per year could be saved
if the potential amount of used cooking oil (16.5 million liters per
year) in the country was converted into biodiesel and more than 14
million liters of petroleum diesel displaced. This would also support
the one of the Thai government’s policy to promote use of biodiesel
in transportation in Thailand.