Tailoring key fuel properties of diesel–biodiesel–ethanol blends for diesel engine

Alternative fuel research for the profusely growing number of diesel run automotive has intensified due to environmental reasons and turmoil in petroleum market. Government initiatives all around the world, their energy policies and steps to emphasis the use of biodiesel; proved biodiesel as a number one renewable substitute for No. 2 diesel fuels. Among all biodiesel feedstock, palm oil is a potential source with higher yield rate without much fertilizer use especially in tropical region. However, the application of transesterified palm biodiesel is objected by many auto-manufacturers due to adverse effects on engine in long term operation. The aim of this study was to modify the key fuel properties of palm biodiesel which causes engine fouling in long term operation. A significant amount of work is devoted to mix biodiesel and diesel at arbitrary percentages and test engine performance. Numerous fuel additives are developed for biodiesels automotive use. In this study, chemical properties of biodiesel are tailored by ethanol and an optimum formulation is derived mathematically. Ethanol is used at a controlled proportion (6%) with palm oil methyl ester (POME) as additive to reduce the higher viscosity of POME. This optimum palm biodiesel–ethanol blend was mixed at varying proportions (i.e. 0–30%) with No. 2 diesel to produce ternary blends of diesel–palm biodiesel–ethanol. Cold flow properties (such as, could point, pour point) of these ternary blends has improved and minute percentage of ethanol adding did not adversely affect the oxidation stability and corrosiveness of the fuel blend. Ethanol has significantly reduces the flash point, but the flammability of ternary blends is classified as Class II; similar to that of diesel. Cetane number is reduced in ternary blends by ethanol. So, palm biodiesel with minute percentage of anhydrous ethanol as additive in the ternary blend significantly improved key fuel properties significantly.