Studies of Fuel Properties and Oxidation Stability of Biodiesel Fuel

Biodiesel fuel has attracted much attention as a carbon neutral fuel because it is made from vegetable oil. Especially in Southeast Asia, there are numerous biofuel resources, such as palm oil and coconut oil, and it is desirable to utilize these for CO2 reduction. In this paper, we evaluate the properties of biodiesel fuel and biodiesel blended diesel oil. The low temperature performance of palm oil methyl ester (PME) is poor and it affects low temperature performance, even if the PME blending rate is low. The oxidation stability is a very important property of biodiesel fuel because degraded biodiesel fuel produces organic acids and polymeric substances. PME contains mainly saturated fatty acids methyl esters, so the oxidation stability is better than other fats and oils. When containing antioxidants such as beta carotene, biodiesel's oxidation stability is improved. In biodiesel blended diesel fuel, the oxidation stability tends to worsen with increasing PME blending rate or fuel temperature. Specific metal materials are one of the factors which accelerate degradation of biodiesel fuel. We compared the effect of copper, zinc, aluminum and aluminum die-casting alloy which contains copper, zinc and other metal materials. Copper accelerates degradation of biodiesel fuel significantly. The influence of aluminum on degradation of biodiesel fuel is smaller than other metal materials, but aluminum die-casting alloy tends to accelerate degradation. The influence of terne sheet on oxidation stability of PME is smaller than that of bonde steel. But terne sheet tends to be corroded by PME more than bonde steel, and corroded terne sheet accelerates PME degradation.