M. A. Mujeeb, A. B. Vedamurthy and Shivasharana C. T.
High fossil fuel prices, energy security concerns, and environmental issues—particularly climate change have motivated countries across the world to explore alternative sources of energy, such as biodiesel. It is a renewable substitute fuel for petroleum diesel or petrodiesel fuel made from vegetable or animal fats; it can be used in any mixture with petrodiesel fuel, as it has very similar characteristics, but with lower exhaust emissions. Biodiesel fuel has better properties than petrodiesel; it is renewable, biodegradable, non-toxic, and essentially free of sulfur and aromatics. Biodiesel seems to be a realistic fuel for future; it has become more attractive recently because of its environmental benefits. Primarily, biodiesel is produced from food crops and mostly oil seeds which are limited in their ability to achieve targets for replacement of fossil diesel, climate change and economic mitigation and their competition with the food has lead to the focus on microalgae which offer a better and reliable source for biodiesel production. This paper reviews the various aspects, methods and technologies associated with the production of biodiesel from available feedstocks such as vegetable oils, animal fats and microalgae with a comprehensive comparison among them.
