Traditionally, the main source of biodiesel is vegetable oil.
The types of vegetable oils available depend on the climate
and soil conditions of the country (Siddiquee and Rohani,
2011). In Thailand, over 90% of biodiesel production is from
palm oil as raw material (Rattanapan et al., 2011). The most
widely used biodiesel feedstock in the United States is soybean
oil (Mondala et al., 2009). Biodiesel feedstock can be
categorized into three types: edible oils, non-edible oils, and
reusable sources or wastes, as summarized in Table 6. Some
researchers are interested in biodiesel production using oi