Abstract:
Jatropha oil has drawn an attention for being developed as an alternative fuel since it comes from non-edible plant. It is classified as a high viscous fuel and that its viscosity is necessary to be reduced before using in Compression Ignition (CI) engines. Transesterification process is the major widely used for alternating vegetable oils to methyl ester (so-called biodiesel), which obtaining glycerol as by-product and a large volume of waste water from the process. In this research, another approach for preparation of biofuel is introduced by using microemulsification process and the products known as microemulsion biodiesohol or MB . This process is environmentally friendly the fact that no waste and by-product are generated. The most important for producing this MB was the most suitable proportion of all components in the product. So, the first phase of this study was to prepare psuedo-ternary phase diagram. The three main components were jatropha oil, ethanol and surfactants. In this study, ethanol and surfactant(s) were mixed and considered as one component called co-surfactant/surfactant (C/S). The results from psuedo-ternary phase diagram and some properties testing indicated that the optimum compositions of microemulsion oil (MO) were 95% jatropha oil and 5% C/S solution which the C/S ratio was 0.5 in the single surfactant system. Eight formulations of MO prepared from both single and mixed surfactant were selected for evaluation for their properties, viscosity, free fatty acid and induction time. The formulation of single surfactant was selected for being MB production for further properties evaluation and performance testing. Due to its high viscosity of the MO, to test their performance with CI engine (Kubota RT 100), the MO was blended with conventional diesel in the proportion of 5/95, 10/90 and 20/80 (V/V%) and subsequently called as MB5, MB10, and MB20, respectively. In addition, biodiesel prepared from jatropha oil as well as neat diesel were also tested for their performance and emission for comparison. The properties of all fuels were evaluated according to ASTM 6751. The results show that most of parameters indicated the MBs properties were met the biodiesel standard. For engine performance and emission measurements, the results of the MBs fuel, especially MB20 and MB10 have high potential for application and were reasonably competative with biodiesl and neat diesel. In conclusion, the transfiguration of jatropha oil by microemulsion process can be a promising technique for producing an alternative fuel.