The world energy consumption highlights th...

Abstract: Owing to higher fossil fuel prices in the coming few years it becomes necessary to search for an alternative fuel which must be clean, green and economical. The 2nd Generation biofuels challenges a sustainable relaxation for whole world and for upcoming generations, if explored efficiently. Biodiesel is a more attractive alternative fuel source for diesel engines as they were well known in their renewability and non-polluted emissions. But the major problem arises for the commercial use of biodiesel is cost. In effect of searching alternative sources and based on experimental data, this review carries a better explanation on Neem (Azhadirachta indica) and Soapnut (Sapindus mukorossi) oil a cheaply available non edible sources, stepping towards the reduction of cost during the production and making as economically feasible model. As non-edible oils were enriched in higher levels of free fatty acid content hence, a two-step catalyzed methods is used in trans esterification process for biodiesel production. The comparison between the biodiesel produced from neem oil and soapnut oil taken place on the basis of their physicochemical characteristics, economic feasibility and eco friendly nature. The efficiency of the biodiesel is further examined in vehicle engine and an overview of gases emissions was noted. The physicochemical properties from obtained biodiesel were under lined based on ASTM values. The observed values of the biodiesel can be compared with the other oil. This review paper mainly focus on extraction of oil, biodiesel processing, physio chemica