Estimation of the oxidation temperature of biodiesels from a limited number of chemical parameters

• Published in: Fuel (Guildford) 2012-12, Vol.102, p.585-591
• Main Authors: dos Reis Albuquerque, Anderson, Maul, Jefferson, dos Santos, Jozemar Pereira, dos Santos, Iêda Maria Garcia, de Souza, Antonio Gouveia
• Format: Article
• Language: English
• Subjects: Applied sciences; Biodiesel; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fuels; Mixture design; Oxidative stability; PDSC
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2012.07.056

[Display omitted] ► Experimental mixture design with fatty acid methyl esters was performed to study oxidative stability. ► The oxidation temperature (OT) was obtained applying non-isothermal PDSC. ► A pseudo-molecular formula CaHbHc∗Hd∗∗He∗∗∗O2(OH)f to represent the mixtures of FAME was developed. ► A quadratic relationship for OT with H∗, H∗∗ and (OH) was found. Biodiesel is a fuel composed by fatty acid esters, usually methyl esters (FAME), have common structural features, as allylic hydrogens, bis-allylic hydrogens and secondary hydroxyl, that determinate its oxidative stability. In this study, the oxidation temperature (OT) of biodiesels formulated from a mixture design of methyl stearate, methyl oleate, methyl linoleate and methyl ricinoleate was determined by pressurized differential scanning calorimetry (PDSC). The generic representation CaHbHc∗Hd∗∗He∗∗∗O2(OH)f for the mixtures was developed and their coefficients were used as parameters to describe the OT. A non-linear dependence of OT with the descriptors of allylic hydrogen Hc∗, bis-allylic hydrogen Hd∗∗ and secondary hydroxyls (OH)f were observed in the empirical domain Dexp={(a;c,d,f) ∈R3; 0⩽c⩽4 and 0⩽d⩽2 and 0⩽f⩽1 and a=19}, where the Ca parameter for chain length was kept fixed.