Location: Bio-oils Research
2024 Annual Report
Objectives
Objective 1. Resolving processing technologies to convert low-quality and nonfood feedstocks into value-added biobased products.
Sub-objective 1.A. Develop low-quality (vegetable oil refining wastes, used cooking oils and greases and residual oils from ethanol fermentation) and nonfood feedstocks for conversion to biodiesel and biobased products. Resolve pretreatment processes and eliminate (or minimize) needs for chemical preparation of low-quality and nonfood (LQNF) feedstocks.
Sub-objective 1.B. Resolve final process technologies for converting low-quality and nonfood (LQNF) feedstocks to biodiesel and value-added coproducts.
Objective 2. Enable commercial processing of new versatile biobased products useful in multiple markets.
Sub-objective 2.A. Enable novel and cost-competitive biobased products with unique structures for applications in multiple industrial sectors.
Sub-objective 2.B. Investigate functional property of novel biobased structures for lubrication, remediation, surfactant/detergent, polymers and other applications; apply structure-property models to optimize the chemical structures for multi-functional application.
This project is aimed at enabling new commercial technologies, processes, and multi-functional biobased products applicable in multiple markets without further modification or processing. Where applicable, low-cost feedstocks from cheap process waste streams will be used. Developed products will have applications in environmental remediation, household and industrial surfactants and detergents, lubricant base oils and additives, cleaners and solvents, polymers and plasticizers, and biofuels and biofuel additives. The technologies and products from this research will be competitive in cost and performance to those currently in the marketplace. The biobased products targeted in this project will result in significant improvements to the U.S. agricultural economy and the environment as well as to the safety and health of the American people.
Approach
Biofuels and biobased products are essential for maintaining a sustainable bioeconomy, protecting the environment, and enhancing the health and safety of citizens. Their widespread application requires efficient and cost-effective processing of farm-based raw materials. Achieving this goal will require overcoming complex technological hurdles to reduce manufacturing costs and expand their ranges of application. This research plan will develop technology for the conversion of low-cost ag-based raw materials to biodiesel and value-added bioproducts with applications in multiple markets. Bioproducts from this research will be developed with potential applications in the environmental remediation of heavy metals from waste streams, household and industrial cleaners, surfactants and detergents, biobased lubricant additives and base oils, fire-resistant polymers and plasticizers, and biodiesel and biodiesel additives. This research project is organized in two main objectives.
Objective one is tasked with the goals of expanding the feedstock supply for conversion to biodiesel and developing alternate conversion processes that produce biodiesel with enhanced cold flow properties. Sub-objective 1.A will expand the feedstock by the development of cost-effective pretreatment processes for upgrading low-quality oils and free fatty acids (FFA) obtained from vegetable oil refining wastes, used cooking oils and greases, and sorghum distiller’s dried grain with solubles (DDGS). Sub-objective 1.B will develop alternative processes for converting low-quality and nonfood (LQNF) feedstocks to biodiesel with improved cold flow properties. These processes will be designed to yield biodiesel mixed with co-products in one conversion step where the co-products can act as built-in cold flow improvers.
Objective two is tasked with the development of multi-functional biobased products from waste cooking oil (WCO) and other low-cost feedstocks. The biobased products will have versatile structures that will allow them to perform in multiple application sectors. Sub-objective 2.A will enable the synthesis of cost-competitive biobased products such as phosphonates, thiophosphates, disulfides, gemini surfactants and polyurethanes (PU). Sub-objective 2B will enable the characterization of these materials in multiple application sectors such as lubrication, environmental remediation, surfactants, detergents and polymers. Structure-property models will be applied to allow for the synthesis of optimized structures of multi-functional biobased products.
Progress Report
In support of Sub-objective 1.A, biodiesel was prepared from non-food pennycress oil that was genetically engineered to contain a high oleic acid concentration (62.7 percent). The high-oleic acid pennycress (HOP) oil was obtained from a collaborator (MTA No. 18818) and converted to fatty acid methyl esters (biodiesel) in-house by ARS researchers in Peoria, Illinois. Fuel properties including cold flow properties, oxidative stability, kinematic viscosity (thickness), density and lubricity (anti-wear) characteristics of the high-oleic acid pennycress (HOP) oil biodiesel were measured, and the results compared with those for biodiesel fuels made from field (unmodified) and low-erucic acid pennycress oils and canola oil. The cold flow properties and viscosity of HOP oil biodiesel were lower than the corresponding properties of canola oil biodiesel despite the latter having a similar oleic acid content (64.9 percent). This work showed that biodiesel with favorable fuel properties can be obtained from HOP oil, a genetically modified pennycress oil obtained from oilseed crops that can be employed as a cover crop in the Middle and Upper Midwestern United States during wintertime.
In support of Sub-objective 1.B, ARS researchers in Peoria, Illinois, determined that the “small molecule” strategy for synthesizing new compounds as fuel enhancing additives yielded minimal or no positive benefits with respect to improving the cold flow properties of biodiesel from soybean oil. These compounds included those obtained from reactions between two types of triacylglycerols and also those between fatty acids or diacids with a branched-chain alcohol. Alternative approaches are under development to continue this line of research, including solid-catalytic conversion of plant seed oils and mixtures of methanol and propanol or butanol mixtures to yield biodiesel admixtures with improved fuel properties.
In support of Sub-objective 2.A, orange seed oil (OSO), an unused by-product of juice production, was converted to biobased thiols. Through chemical transformations, newly formed biobased thiols were converted to thiophosphates. The resulting biobased thiophosphates are expected to be an efficient substitute of commercial lubricant additive(s).
In support of Sub-objective 2.B, studies comparing the tribological (lubricating) properties of biobased thiophosphates, made from orange seed oil, with a commercial additive as additives for base lubricant oils were initiated. The testing should show the two materials have the same effects to control oxidation (limit reaction with oxygen) in biobased lubricants.
Accomplishments
1. Mathematical models to more accurately calculate the shelf-life of biodiesel. Biodiesel (fatty acid methyl esters [FAME]) is a renewable biomass-based diesel and home heating fuel made from plant oils, animal fats, and waste greases. Its production is increasing worldwide as more countries are moving to boost the use of fuels from renewable energy sources. Biodiesel has poor oxidative stability which can lead to degradation of its fuel quality during long storage periods. ARS researchers in Peoria, Illinois, developed mathematical models from experimental data that more accurately calculated the shelf-life of biodiesel made from canola, palm, and soybean oils. This work benefits biodiesel fuel producers, terminal operators, and consumers that may need to store biodiesel in warm weather.
2. More efficient small sample cold flow method developed to test prospective lubricants. Cold flow properties are an important factor when new liquid materials are being evaluated for potential use as lubricants. Industry-accepted methods (ASTM D97 and D2500) for these properties require large volumes (50+ mL) to test prospective new lubricants. In many circumstances, preparing large volumes of test material in a timely manner is challenging. ARS researchers in Peoria, Illinois, compared results from the aforementioned test methods to those from automated small sample volume methods (ASTM D5773 and D5949) for a series of biobased oils (estolides). The results indicate that the small volume methods can be substituted for older methods for biobased lubricants that were light in color and opacity. This work will advance the development and utilization of new biobased lubricants and lubricant formulations by helping scientists and engineers evaluate the cold flow properties of these materials.
Review Publications
Yosief, H.O., Sarker, M.I., Bantchev, G.B., Dunn, R.O. 2023. Isopropyl-branched lard and its potential application as a bio-based lubricant. Lubrication Science. https://doi.org/10.1002/ls.1673.
Winfield, D.D., Dunn, R.O., Moser, J.K., Cermak, S.C., Marks, M.D. 2024. Characterization, physical properties, and potential industrial applications of high oleic pennycress oil. Industrial Crops and Products. https://doi.org/10.1016/j.indcrop.2024.118095.
Winfield, D.D., Cermak, S.C., Evangelista, R.L., Moser, B.R., McKinney, J., Pantalone, V. 2023. Evaluation of a high oleic soybean oil variety in lubricant and biodiesel applications. Journal of the American Oil Chemists' Society. https://doi.org/10.1002/aocs.12788.
Dunn, R.O. 2024. Shelf-life of biodiesel by isothermal oxidation induction period at variable temperatures. Journal of the American Oil Chemists' Society. https://doi.org/10.1002/aocs.12848.
Moser, J.K., Ashby, R.D., Yosief, H.O., Msanne, J.N., Peterson, S.C., Bantchev, G.B., Cermak, S.C., Felker, F.C. 2024. Properties of soybean oil oleogels produced from sophorolipid-derived hydroxy fatty acids, methyl esters and hydrogenated Lesquerella seed oil. Journal of the American Oil Chemists' Society. https://doi.org/10.1002/aocs.12843.
Bantchev, G.B., Lew, H.N., Chen, Y., Winfield, D.D., Cermak, S.C. 2024. Cold-flow properties of estolides: The older (D97 and D2500) versus the mini-(D5773 and D5949) methods. Lubricants. https://doi.org/10.3390/lubricants12050141.