Alternative fuels have recently received much attention due to
several reasons such as increasing environmental concerns (i.e., high
emissions of carbon dioxide and greenhouse gases), non-renewability
of fossil fuels and their depletion in the near future, and price instability of fossil fuels for the countries with limited resources[1].
Biodiesel is a mixture of mono-alkyl esters of long chain fatty
acids that is derived from the reaction of renewable lipid material
with alcohol[2,3]. The major problem of biodiesel commercialization is its high price[4]. It should be noted that 80% of the biodiesel
price is related to the feedstock[5]. Many reports indicate that the
waste fish oil (WFO) is a good feedstock for biodiesel production
due to its low cost, and solving the problem of waste oil disposal
[6–8]. WFO is a byproduct of fishmeal factory produced from fish
product wastes (mainly heads, bones, skin, viscera, etc.)[9].WFO
biodiesel has a higher cetane number in comparison with other oils
and as a result, better performance of diesel motor and lower pollution can be achieved using WFO biodiesel [10]. For biodiesel
production, waste oils have low quality characteristics such as high
free fatty acid (FFA) content