Hydrodeoxygenation-alkylation pathway for the synthesis of a sustainable lubricant improver from plant oils and lignin-derived phenols

Authors: MAGLINAO, RANDY - Montana State University; RESURRECCION, ELEAZER - Montana State University; KUMAR, SANDEEP - Old Dominion University; MAGLINAO JR., AMADO - Texas A&M University; CAPAREDA, SERGIO - Texas A&M University; Moser, Bryan

Submitted to: Industrial and Engineering Chemistry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/22/2019
Publication Date: 1/22/2019
Citation: Maglinao, R.L., Resurreccion, E.P., Kumar, S., Maglinao, Jr., A.L., Capareda, S., Moser, B.R. 2019. Hydrodeoxygenation-alkylation pathway for the synthesis of a sustainable lubricant improver from plant oils and lignin-derived phenols. Industrial and Engineering Chemistry Research. 58(10):4317-4330. https://doi.org/10.1021/acs.iecr.8b05188.
DOI: https://doi.org/10.1021/acs.iecr.8b05188

Interpretive Summary: This research describes a sustainable route to renewable lubricants for diesel fuels from vegetable oils and lignin. Renewable lubricants are important because they represent bio-based alternatives to existing petrochemically-based materials and because diesel fuel requires lubricant additives to prevent unwanted engine friction and wear. This research discovered that phenolic compounds obtained from lignin can be chemically combined with fatty acids to give lubricants with excellent low temperature and oxidative stability properties. Oxidative stability and low temperature performance are important because fuels and their components need to be stable and remain liquid throughout storage, regardless of temperature. This research may ultimately provide a renewable diesel fuel lubricant derived from agricultural materials, thus further reducing the environmental impact of and demand for petroleum-derived lubricants while simultaneously enhancing rural economies by increasing the use of agricultural products.

Technical Abstract: Fatty acid methyl esters (FAME) derived from plant oils are excellent lubricant improvers, but they do not have desirable oxidative stability and cold flow properties. This study investigated phenol hydrodeoxygenation in hexadecane and aromatic alkylation of FAMEs over a K30 montmorillonite catalyst to give phenyl-branched FAME (PBFAME) as a potential lubricant improver. The high selectivity to aromatic hydrocarbons during hydrodeoxygenation over Pd/C was likely due to the slow hydrogenation rate of phenols in hexadecane, absence of hydrogen bonding in nonpolar solvents allowing hydroxyl groups to participate in dehydration reactions, and limited diffusion of hydrogen from bulk solution to Pd sites. Isomers of methyl (methylphenyl)octadecanoate (n-MMPO) were produced during toluene alkylation of methyl oleate. The presence of both Bronsted and Lewis acid sites in K30 facilitated selective synthesis of n-MMPOs. The oxidative stability and cold flow properties of n-MMPO were better than those of canola biodiesel.