1. Introduction
Presently, fossil fuel is the main fuel driving
industrial activities, transportation, and household
consumption. The shortage of fossil fuel is a
significant issue in the world, stimulating the
discovery of alternative fuels. There are several
alternative fuels being developed, such as
bioethanol, biohydrogen, biogas, and biodiesel.
Biodiesel has been explored as an alternative
energy source which plays an important role in
addressing these issues. Biodiesel can be
produced from vegetable oil (soybean, palm,