Biofuel production from palm oil by using microemulsion technique

Abstract

Biofuel is becoming more attractive because of the rising crude oil price and its environmental benefits from its renewability and less greenhouse pollutants generation. Microemulsion is a system of homogeneous phase combining of oil, water, surfactant and cosurfactant. In biodiesel preparation, microemulsion occurs by facilitating fatty acids, a major component of vegetable oils, to cooperate with the surfactant and cosurfactant and very small amount of water to form a transparent homogeneous phase called microemulsion fuel. This technique is simple and low energy needed for the process. In addition, there is no by-product generated. The microemulsion biofuel from this study was called MB100, which contained a cosurfactant, a nonionic surfactant, water, and palm oil. To obtain the composition for MB100 for further study on properties and performance, ternary phase diagrams were prepared in order to obtain the suitable ratio of microemulsion biofuel. In the phase study, the results show that a cosurfactant/surfactant ratio or C/S ratio of 0.5 produced a larger area of homogeneous transparent solution in ternary phase diagram. Using this ratio, a fuel composition of 95% palm oil, 4.95% C/S at a ratio of 0.5, and 0.05% water by weight was able to produce homogeneous solution microemulsion biofuel. At this composition, the product was selected for properties and performance study. Besides MB100, two fuel blends of MB100 and diesel at ratios of 20:80 and 5:95, called MB20 and MB5 were also evaluated. The fuel properties were tested following the ASTM method for their performance and their exhaust emissions of the three types of microemulsion biofuel were also determined. The fuel properties tests revealed that the microemulsion biofuels (i.e., MB100, MB20 and MB5) could meet petroleum diesel and biodiesel property standards. For fuel performance tests and exhaust emission measurements, the results showed that the microemulsion biofuels were performed similar to those of conventional diesel fuel and produced less exhaust emissions as compared to petroleum diesel. In addition to those evaluations, our products MB100, MB20 and MB5 were also found to be able to maintain their stability in the temperature range of 20-70°C.