Environmental impact of using biodiesel as fuel in transportation: a review

The environmental pollution and global warming associated with the use of fossil fuels, has forced a search for alternative fuels in transportation. This paper presents a review of the use of biodiesel in CI engines and its environmental impacts. There is a significant reduction in the emission of unburned hydrocarbons, polyaromatic hydrocarbons and soot, particulate matters, carbon monoxide, carbon dioxide and sulfur dioxide with biodiesel. Smoke opacity also decreases, but the NOx emission is more with biodiesel. It is evident from the study that biodiesel can only replace conventional diesel to some extent due to economic, social and other constraints.