Biolubricant basestocks synthesis using 5-step reaction from jatropha oil, soybean oil, and palm fatty acid distillate

Abstract

This research presents a 5-step chemical reaction and modifications to convert triglyceride of jatropha and soybean oils to biolubricant. Saponification and hydrolysis (1st), urea crystallization (2nd), epoxidation (3rd), epoxide ring opening (4th), and esterification (5th) were performed in a series. At first, jatropha and soybean oils were saponified and hydrolyzed, and unsaturated fatty acid (UFA) was separated. After hydrolysis, free fatty acid (FFA) of jatropha and soybean oils increased from 5.02 % and 0.00%–99.66% and 99.75 %, respectively. Next, UFA was successfully separated by urea crystallization, and UFA increased from 79.10%–97.98 % in jatropha oil and from 84.14%–99.64% in soybean oil. Palm fatty acid distillate (PFAD), a cheap co-product from palm oil factories, was used in the reaction to make branching molecules, and 1% (w/w) H2SO4 was the catalyst in esterification. All structure modifications were confirmed by GC-FID, 1H-NMR, and 13C-NMR, and the physical and chemical properties of the final products were analyzed. The confirmation of ≥90.09 % epoxidation was done by 1H-NMR. A 1.0:1.0 mol ratio of PFAD: epoxidized fatty acid (EFA) at 110 °C for the epoxide ring opening reaction and a 1.0:2.5 mol ratio of epoxide ring opening product (EROP):2-ethylhexanol (2-EtH) for the esterification were chosen, as this resulted in the highest conversion of ester products in both jatropha and soybean. The synthesized biolubricant basestocks appear to be suitable for a hydraulic fluid application, ISO 15380 in the HEES category.