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,
jatropha, and waste cooking oil) and animal
fat, as is widely known. In addition, microalgae
oil can be the raw material to produce biodiesel
since microalgae has a higher oil yield per crop
area compared to other feedstocks [1]. Biodiesel
is biodegradable and non-toxic. In terms of
combustion, it has lower emissions of carbon
monoxide, sulfur oxide, and other pollutants
compared to petroleum-based diesel [2]. The
higher flash point (150๐C) of biodiesel means that
it is safer than petroleum diesel for storage,
transportation, and handling [3]. In addition,
biodiesel can be mixed with petroleum diesel