Synthesis of sustainable lubricant enhancer from wet hydrolyzed solids

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: American Society of Agricultural and Biological Engineers
Publication Type: Abstract Only
Publication Acceptance Date: 1/30/2018
Publication Date: 7/29/2018
Citation: Maglinao, R., Resurreccion, E., Kumar, S., Maglinao Jr, A., Capareda, S., Moser, B.R. 2018. Synthesis of sustainable lubricant enhancer from wet hydrolyzed solids [abstract]. American Society of Agricultural and Biological Engineers (ASABE) Annual International Meeting, July 29-August 1, 2018, Detroit, MI.

Interpretive Summary:

Technical Abstract: Lignocellulosic ethanol biorefineries offer a sustainable way to produce alternative transportation fuel and provide fiber and biomaterial. However, the lignin fraction remains underutilized in the absence of the development of high value products. Despite its resilience to decomposition, thermochemical processes can depolymerize lignin into its phenolic monomers which could be utilized as sustainable high-value additive products for fuels and lubricating oils. To achieve the maximum yield of additive products, lignin must first be decomposed into a high concentration of phenol and alkylphenols and then selectively transform these phenolic derivatives into a compound with a chemical structure fit for its purpose. Hydrothermal liquefaction (HTL) of wet unhydrolyzed solids (UHS), a by-product of lignocellulosic ethanol production, generates a bio-oil with 98% phenolic compounds of which more than half of it are phenol and alkylphenols. This phenolic bio-oil can be upgraded into aromatic hydrocarbons via hydrodeoxygenation, then selectively converted into lubricant enhancers by alkylation with fatty acid alkyl esters. This lignin-based product has a polar head, a long-chain alkyl group, and an aromatic component. These combined components makes the product a suitable lubricant enhancer, as well as an additive that improves lubricity of fuels and lubricating oils. The polar head allows the compound to bind to metal surfaces in the engine to create a protective layer against wear and tear, the long-chain alkyl group helps its solubility in nonpolar fuels and oils, and the aromatic component provides resistance to decomposition under high temperatures. This arrangement of reactions allows the utilization of lignin by adding value to lignocellulosic ethanol. This collaborative research studied the sequence of thermochemical reactions to selectively transform lignin into a sustainable lubricant enhancer. Lab-scale experiments, specifically phenol hydrodeoxygenation and alkylbenzene alkylation with fatty acid alkyl esters, showed that the synthesis of a sustainable lignin-based lubricant enhancer can be achieved and the process can be integrated into the production of lignocellulosic ethanol. Performance properties such as oxidative stability and cloud point of the lignin-based lubricant enhancer is significantly better than fatty acid alkyl esters.