Abstract
Vehicles are the main sources for environmental pollution especially those associated with diesel engines. It causes a number of health diseases and harm to the ecosystem. It is very urgent to find alternative fuel for vehicles. Biofuel is an alternative for vehicles which have potential to reduce engine emissions and maintain the air quality better. In recent years, worldwide biofuel production and use raised drastically. Some developed countries have put their target and mandate to use biofuel. The aim of this review is to discuss the impact of biofuel on diesel engines emission. From this review it is found that biofuel significantly reduces engine emissions and it has potential to reduce more than 80% of GHG emission. Finally, biofuel can be a viable alternative to be used as a transportation fuel. (C) 2015 The Authors. Published by Elsevier Ltd.