Prediction of Fuel-related Properties of papaya Seed Oil and Lard Oil Methyl esters from their fatty acid methyl ester compositions-based models

This work aims to establish a correlation between the compositions of fatty acid methyl ester (FAME) and the key fuel properties of methyl ester. The experimental data of the analysis was obtained from the methyl esters of calcined hybrid-banana-plantain-peel ash (CHBPPA)-catalyzed methanolysis of papaya seed oil (PSO) and lard oil (LO) produced at the optimal reaction conditions of temperature 60oC:57oC, catalyst amount 2.5 wt.%:2.5 wt.%, time 1 h:1.5 h, and methanol/oil molar ratio 9:1:10.5:1, respectively. PSO and LO methyl esters were characterized using American Society for Testing and Materials (ASTM) methods, as well as Fourier-Transform-Infrared-Spectroscopy (FTIR) and Gas Chromatography-Mass Spectrometry (GC-MS) to determine their physicochemical properties, functional groups, and FAME compositions. Methyl Oleate (C19H36O2) was identified as the dominant ester in PSO (48.01%) and LO (31.63%) methyl esters. PSO methyl ester was found to possess 54% monounsaturated fatty acids, while LO methyl ester was predominantly composed of 58% saturated fatty acids. The predicted fuel properties included cetane number (CN), higher heating value (HHV), iodine value (IV), and saponification value (SV). These predicted values, derived from the FAME profiles, were compared with experimental values obtained through ASTM standard testing. The average absolute deviations (AAD) between predicted and experimental values for PSO and LO methyl esters were 3.64:4.85, 0.83:1.92, 11.66:10.46, and 2.16:3.29% for CN, HHV, IV, and SV, respectively, indicating a good correlation. Hence, a satisfactory prediction of the fuel-related properties based on the FAME composition can be given by the models, signaling the possibility of establishing a cost-effective and improved efficiency process. Keywords: fatty acid methyl ester (FAME), fuel properties, lard oil, models, papaya seed oil, prediction