(680a) Ecofriendly Biolubricant Production from Waste Cooking Oil and Lignocellulosic Biomass-Derived Oxygenates

Waste cooling oils typically contain triglycerides, long chain fatty acids, and other oxidation products. Hence, in terms of molecular size and carbon chain length, waste cooking oil (WCO) is a suitable raw material for lubricant production. However, the biolubricants produced via (trans)esterification, etherification, and C=C epoxidation of WCO have one or more negative characteristics such as poor flow properties, low oxidation stability, and insufficient solubility of additives. This study presents a novel approach to produce biolubricants from the reaction of WCO and cyclic oxygenated hydrocarbons (cyclopentanone, cyclopentanol, anisole, and 2-methylfuran) via a four-step pathway including hydrolysis, dehydration, Friedel−Crafts (FC) acylation/alkylation, and hydrotreatment. The process resulted in the production of biolubricants with unique molecular structure that are consisted of a long chain with one or two naphthenic ring(s) attached to it. These structures share several positive properties: 1) long and linear hydrocarbon chains can provide good lubricity (by reducing the boundary friction coefficient) and viscosity index (VI), 2) low-to-zero unsaturation to give improved stability to the mixture, 3) minimal branching that may lower wearing rate, 4) the presence of a naphthenic rings to increase oxidation resistance, boost solvency capacity (thus, improve its response to additives), decrease viscosity variations with temperature (increase VI), and lower the pour point (PP), and 5) high polarity to ensure a good boundary layer with a metal surface. We showed that such biolubricants can be synthesized with pour-point, kinematic viscosity (at 40°C), viscosity index, and Noack volatility of −12°C, 47.5 cP, 186, and 17 wt.%, respectively. Furthermore, a major challenge associated with bio-lubricants is their solvency capacity for additives and their poor miscibility in petroleum-lubricants. We have demonstrated that the bio-lubricant produced via our method is fully miscible with VHVI-6 (a commercial base fluid with no additives) and 0W-20 full synthetic engine oil.