Study on Volatility of Palm Oil Biodiesel/-10 Petrodiesel by Thermogravimetric Analysis Technique

Abstract

Palm methyl ester (PME) was prepared from palm oil through transesterification using NaOH as catalyst. Chemical composition of the PME and -10 petrodiesel (-10PD) was determined by gas chromatography-mass spectrometer (GC-MS). The PME and -10PD were characterized for their fuel properties including density, kinematic viscosity, and flash point, cold filter plugging point, sulfur content, copper strip corrosion and oxidative stability. Volatility was measured by thermogravimetric analysis (TGA). Volatile index was proposed to describe PME/-10PD volatility. A good correlation model was put forward for calculating the PME/-10PD volatility by PME blending ratio. The study showed that PME was mainly composed of long chain fatty acid methyl esters (FAMEs): C14:0－C24:0, C16:1－C22:1, C18:2 and C18:3. -10PD was mainly composed of long chain alkanes: C8－C26. The fuel properties of PME were within the limits prescribed in the GB/T 20828-2007 standards for biodiesel. With respect to -10PD, volatilization of PME was stronger and quicker, but volatilization onset at higher temperature. The volatilization onset temperatures of PME and -10PD were 448.9 and 361.7 K respectively; and the volatile indexes were 1.76E-04 and 3.64E-05 respectively. The PME/-10PD volatility had relation to PME blending ratio. The volatility of B0－B20 was very close to the -10PD. The volatility of B20－B100 was better with increasing the PME blending ratio.