Effects of Different Additives on Performance and Emission of Biodiesel Fuelled Compression Ignition Engine

Due to the growing concern over greenhouse gases, Biodiesel is widely accepted as comparable fuel to diesel in diesel engines, as it is renewable, sustainable and alternative fuel for compression ignition engines. Biodiesel provides several factors like decreasing the dependence on imported petroleum, reducing global warming, increasing lubricity, and reducing substantially the exhaust emissions from diesel engine. However, there are some disadvantages in the use of biodiesel as it has lower heating value, higher density and higher viscosity, higher fuel consumption and higher NOX emission which limits its application. Here additives become essential tools not only to minimize these drawbacks but also promote use of biodiesel to meet the regional and international standards. Additives can contribute towards fuel economy and emission reduction either directly or indirectly without engine modification. A variety of additives are used in biodiesel fuel to meet specification limits and to enhance quality. For example, alcohol based ethanol, methanol, diethyl ether, gas based hydrogen, oxygen, metal based magnesium, aluminium, ferric chloride, butanol, manganese, cerium oxide and nano fuels etc used to meet specifications and quality. In this article variety of research papers reviewed to understand effects of various proportion of additives on different conditions of engine performance and exhaust emissions. The review concludes that the use of additives in biodiesel is need of hour to get better engine performance and emission characteristics for CI engine.