2014 年 49 巻 2 号 p. 253-259
A study was conducted on the feasibility of crudely processed fatty acid methyl ester (FAME). FAME is receiving considerable attention as a promising alternative fuel to address global warming. However, its high cost and its long and complicated manufacturing process prevent its wider use. If the amount of methanol used in the fuel making process is reduced, the fuel cost would be reduced. The aim of this study is to clarify the feasibility of simplifying the FAME manufacturing process and of reducing costs by decreasing the amount of methanol used. Therefore, in the experiment described in this paper, test fuels with methanol percentages of 10, 20, and 30% were prepared. Moreover, the pre-manufacturing process and the washing process were eliminated. In addition, FAME produced by the complete manufacturing process was used as the reference fuel. The lower calorific value, density, surface tension, and kinematic viscosity of the test fuels were measured. It was found that the reduction of methanol had little effect on the thermophysical properties. Moreover, the ignition temperature and the ignition delay were measured and found to improve with esterification. No significant differences were found for all FAME fuels. Finally, all FAME fuels were burned in a conventional 273-cc diesel engine. Although the specific fuel consumption was slightly higher, the smoke scale in the exhaust gas was lower than that of gas oil. FAME with 20% methanol was especially similar to that with 30%. There were only small differences between crudely processed FAME manufactured using the simplified process and that which was manufactured with the complete process.