Litsea cubeba kernel oil as a promising new medium-chain saturated fatty acid feedstock for biolubricant base oil synthesis

Abstract

Abstract Litsea cubeba (LC) kernel is a kind of waste after LC essential oil processing, which oil was found to be rich in medium chain fatty acids. Such oil was originally applied as a potential feedstock for the synthesis of trimethylolpropane fatty acid triester (TFATE) as a biolubricant base oil with desirable lubricating properties. LC kernel oil was firstly decolorized, and then treated by glycerolysis and methanolysis to produce LC fatty acid methyl ester (FAME). The biolubricant base oil was produced by the transesterification of LC FAME with trimethylolpropane (TMP) catalyzed by TMP-potassium, where reaction conditions were FAME to TMP ratio (4:1), catalyst dosage (10 % based on TMP), pressure (100\u202fPa), temperature (130\u202f°C) and time (1\u202fh). The products from each processing step were characterized by GC-FID, ATR-FTIR, and DSC to make sure the reaction complete. The purified product with 92.0 % of TFATE was finally obtained by molecular distillation, which lubricating properties were qualified according to ISO VG 32 standard. The present findings proposed that LC kernel oil could be used as a promising alternative biolubricant feedstock as its derived TFATE product could achieve good oxidative stability (35\u202fmin, ROBT 150\u202f°C) and low-temperature performance (pour point of -15\u202f°C).