Production of biolubricant samples from palm kernel oil using different chemical modification approaches

Abstract

Abstract This work focused on the chemical synthesis and characterization of palm kernel oil (PKO) for biolubricant production using transesterification of palm kernel methyl ester with trimethylolpropane (TMP) and epoxidation‐esterification methods. The PKO was extracted using solvent extraction method. The physicochemical characteristics of the PKO and produced biolubricant samples were determined using standard methods. Fourier transform infrared (FTIR) spectrometry and gas chromatographic (GC) analyses were used to determine the predominant functional groups and fatty acids of PKO and the produced biolubricant samples, respectively. The kernel oil yield of 49.82% (by weight) was obtained at 55°C, 150 min and 0.5 mm particle size. The viscosities at 40°C, 100°C, viscosity index, pour and flash points of the biolubricants produced by transesterification with TMP (PKBLT) and epoxidation‐esterification (PKBLE) methods, were (42.53 cSt, 10.65 cSt, 139, −11°C, 235°C) and (44.69 cSt, 11.42 cSt, 132, −12°C, 240°C), respectively. Time, mole ratio, and temperature effects were the main factors that significantly influenced the transesterification and epoxidation processes. The obtained physicochemical properties of PKBLE and PKBLT samples showed conformity with ISO VG 32 standard, hence their possible application as biolubricant basestock. Furthermore, the presences of the C–H, OH functional groups in the FTIR results, indicate the biodegradability of the produced biolubricant samples; while the GC analyses indicate that the samples were mainly saturated fatty acids.

Keywords

• biolubricant
• epoxidation‐esterification
• palm kernel
• transesterification
• trimethylolpropane