The numerous challenges associated with declining fossil fuel reserves as energy sources, have accounted
for a shift to biofuels as alternatives. However, transesterification of animal fats and edible vegetable oils
using homogeneous acids and bases for biodiesel production is recently considered unsustainable by
industries, particularly due to food versus fuel competition, and economic and environmental challenges
associated with the feedstocks and catalyst systems, respectively. The paper therefore presents a critical
review on the prospects of non-edible oil (i.e. algae oil) for biodiesel production via heterogeneous
catalysis. It covers the advantages of algae oil exploitation over edible oil feedstocks, progress made in
the oil extraction, available heterogeneous catalyst systems and reaction mechanisms, optimum transesterification
conditions and the way forward. As the economic feasibility of biodiesel production from
algae is supported by the valorization of glycerol as by-product, we have also highlighted key available
heterogeneous catalysts to upgrade glycerol into more useful industrial products