The sustainability of biodiesel synthesis from different feedstocks: a review

Abstract

Currently, the world is facing an energy crisis due to an increase in the global energy demand and this has led to an increased dependence on fossil fuels for energy generation and transportation. The steady rise in the world population which is more than seven billion currently is met with an increase in fossil fuel consumption thereby increasing the threat of fossil depletion and an apparent energy deficit. Fossil fuel emissions pose a threat to the environment and the general human population due to risks posed by greenhouse gases they produce. Biodiesel is recognized as a suitable alternative to fossil fuels due to its biodegradable, renewable and environmentally friendly nature. Biodiesel sources are classified into first, second and third generation based on their origin and type of feedstocks used. There are fourth-generation feedstocks which are biologically man-made resources that are currently at the embryotic stage of research. This paper reviews the sustainability of using Jatropha curcas seeds and microalgae for the production of biodiesel. It highlights an evaluation of the oil yield, composition and performance of the biodiesel derived from both sources whilst assessing the viability of individual feedstocks in biodiesel production. Additionally, different methods of biodiesel production are also assessed.