Fuel Properties of Palm Oil Biodiesel and Its Blends With Diesel

Abstract

Palm oil biodiesel was produced from two varieties of the oil palm, the Dura (native variety) and the Tenera (improved variety), by the process of transesterification. The Dura palm oil biodiesel, indicated as B₁100 and the Tenera palmoil biodiesel, B₂100, were tested to determine some fuel properties such as density, kinematic viscosity, flash point, pour point, cetane number (CN) and heat of combustion or calorific value, using the American Standard Test and Measurement (ASTM) methods and specifications. The Nigerian National Petroleum Corporation (NNPC) diesel, the Automotive Gas Oil (AGO) was used as the reference fuel. Also, the blends of the two types of palm oil biodiesel with diesel at 10%, 20%, 30% and 50% biodiesel inclusion were tested for the same fuel properties. The specific gravity (S.G.) at 15 °C of B₁100 was 0.8855 and that of B₂100 was 0.9122 as compared with diesel of 0.8709. The Dura biodiesel has met the international standard, which stipulates the range as 0.86-0.90. The specific gravity and the API gravity (both at 15 °C) of all the blends with diesel, especially at 10 and 20% biodiesel inclusion were about the same as that of the diesel. The kinematic viscosity of B₁100 was close to that of diesel while that of B₂100 was higher. All the blends with diesel, especially 10-30 % biodiesel inclusion were like diesel and met ASTM specifications of the range, 1.60-5.50. The flash point and the pour point followed the same trend, with the blends exhibiting similarities almost exactly with diesel. Dura biodiesel had the highest CN of 51.12 while Tenera had the lowest, 42.01. Diesel had CN of 45.7. All the blends had CN higher than that of diesel. The high CN values indicate the high level of auto-ignition of these fuels, desirability in diesel fuel. The calorific value of the pure biodiesels were a bit lower than that of diesel but the blends, 10 & 20% biodiesel inclusion, had higher heat contents than diesel.