Abstract
Gradual depletion of fossil fuel has greatly enhanced the necessity to look for alternative fuel for automotive engine. In response to this, biodiesel is being considered as a promising solution with a number of technical advantages over conventional petroleum diesel. However, commercial use of biodiesel has been limited because of some drawbacks including corrosivity, instability of fuel properties, higher viscosity, etc. Stability of fuel properties is especially important to ensure expected engine performance as well as engine life. Most of the research papers available in public domain reported some concerns on the stability of biodiesel fuel properties. Scattered studies on different aspects often lead to confusions in understanding the adverse effects of different factors on the degradation of biodiesel. In this article, different factors that cause instability in biodiesel and their possible implications of different fuel properties have been reviewed. A special emphasis has been given to explain the possible mechanisms of biodiesel degradation. Possible remedies to improve the stability of biodiesel have also been included. Finally, some general conclusions concerning these problems are summarized and further scopes of study have been suggested.