Rice bran oil-based biodiesel as a promising renewable fuel alternative to petrodiesel: A review

Abstract The drastic rise in global warming and the fossil fuel consumption have resulted in destruction of the ecological balance, reduction of the environmental quality, and demotion of the sustainable development. The utilization of biofuels have been paid much attention to by researchers and policy makers due to its benefits and indisputable contributions to protect the living environment. Free fatty acid-rich rice bran oil which is unsuitable for food purposes could be a good candidate for biofuel production. Accordingly, rice bran oil-based biofuels (straight oil and its biodiesel) as promising alternative fuels to petrodiesel were reviewed in this article from the sources, components, and physicochemical perspectives. In addition, biodiesel production from rice bran oil using various methods and catalysts was thoroughly detailed. The oxidative stability of rice bran biodiesel as a function of the storage time was also discussed. The application of rice bran oil-based biofuels to diesel engines was completely analyzed and critically discussed based on engine performance, combustion, and emissions characteristics. The effects of using rice bran oil-based biofuels on the lubricating oil degradation, deposit formation, wear, and sound intensity of diesel engines were explained in detail. Finally, the economic aspects of using rice bran oil and its biodiesel as fuels were also assessed. As a conclusion, the blend containing 20% rice bran oil biodiesel and 80% petrodiesel fuel, both in volume, could be the most effective composition considering the techno-economic aspects of diesel engines; meanwhile the remaining blends appeared to be improper for the existing diesel engines.