Location: Bio-oils Research
2022 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
Objective 1.A: The main compounds present in sorghum grain distillers’ residual oil were identified. The important waxy components in the residual oil were characterized. This is a first step in finding an efficient means to separate the waxes and oils for conversion to value-added biobased fuels and products. In addition, membranes capable of separating free fatty acids from vegetable oil waste streams and used cooking oils were selected based on their performance features.
Acquired and converted low erucic acid pennycress oil to biodiesel. The fuel properties of the modified pennycress oil biodiesel were measured and compared against the same data for biodiesel made from other plant seed oil feedstocks. Findings showed that cloud point, storage (oxidation) stability, viscosity (resistance to flow), and density were similar to the same properties of canola and soybean oil biodiesel fuels.
Objective 1.B: Additives that improve the fuel properties of biodiesel were synthesized. The experimental methods, catalysts, reaction conditions, product isolation steps, and analytical procedures were developed to synthesize the additives. Efficient and scalable reactions based on schemes outlined in the project plan were conducted. The effects of synthesized products on the cold flow properties of biodiesel were tested. Unpublished results indicated that some of the additives showed promise, with respect to decreasing the cloud point and pour point of soybean oil biodiesel.
Objective 2.A: A sample of citrus seed oil (an unutilized byproduct from orange juice preparation) was studied. The oil, received from ARS researchers in Fort Pierce, Florida, was analyzed for fatty acid composition and free fatty acids content. The oil was successfully made into fatty acid methyl esters and, after that, into phosphonates. Two newly reported catalysts and three commercial cation exchange resins were compared in their effectiveness in esterification of oleic acid. Results showed that one of the cation exchange resins was the most effective catalyst for this reaction.
Objective 2.B: Evaluated the performance of a phosphonate-lubricant additive obtained under Objective 2.A. The phosphonate was added at 5% to a synthetic base lubricant and tested in a device that rubs stainless steel surfaces against each other. The additive helped reduce the wear scar by 33% and coefficient of friction by 27%.
Accomplishments
1. Developed predictive models to accurately measure relative storage stability of biodiesel made from new nonfood feedstocks. The fuel properties of biodiesel affect its performance in commercial operations. The ability of biodiesel to resist degradation in fuel quality during storage is important, especially when it is stored at temperatures above 25 degrees Celsius (77 degrees Farenheit). ARS researchers in Peoria, Illinois, analyzed canola, palm, and soybean oil biodiesel fuel decomposition and developed mathematical models that accurately predict the relative stability of the fuel at different storage temperatures. This work yielded reference data and enabled accurate predictions that will assist efforts to identify and test new nonfood oils, with diverse chemical compositions, for conversion to biodiesel. In terms of storage stability, results from the study will benefit biodiesel fuel producers, terminal operators, and other users who need to store biodiesel in warm weather.
2. Converted used cooking oil into lubricant additives while simultaneously reducing hazardous waste. Humans generate more than 15 million tons of waste vegetable oil per year. Most of the waste vegetable oil requires discarding which is expensive especially in locations that require it to be treated as hazardous waste. ARS researchers in Peoria, Illinois, successfully analyzed and converted waste cooking oil into phosphonates. These phosphonates are effective wear reducers when used in lubricant formulations. The findings will help reduce the used cooking oil sent to waste and will help formulators wanting to increase the use of biobased lubricants.
Review Publications
Bantchev, G.B., Lorenzo-Martin, C., Ajayi, O.O. 2021. Phosphonates from lipids – Synthesis and tribological evaluation. In: Sarker, M.I., Liu, L.-S., Yadav, M.P., Yosief, H.O., Hussain, S.A., editors. Conversion of Renewable Biomass into Bioproducts. ACS Symposium Series 1392. Washington, DC: ACS Publications. p. 139-156. https://doi.org/10.1021/bk-2021-1392.ch008.
Bantchev, G.B., Cermak, S.C. 2022. Correlating viscosity of 2-ethylhexyl oleic estolide esters to their molecular weight. Fuel. 309. Article 122190. https://doi.org/10.1016/j.fuel.2021.122190.
Dunn, R.O. 2022. Fuel properties of low-erucic acid pennycress (LEAP) oil biodiesel. Industrial Crops and Products. 178. Article 114543. https://doi.org/10.1016/j.indcrop.2022.114543.
Yosief, H.O., Sarker, M.I., Bantchev, G.B., Dunn, R.O., Cermak, S.C. 2022. Physico-chemical and tribological properties of isopropyl-branched chicken fat. Fuel. 316. Article 123293. https://doi.org/10.1016/j.fuel.2022.123293.
Biresaw, G., Chen, Y., Chen, L., Ngo, H., Wagner, K., Vermillion, K., Cermak, S.C. 2022. Iso-oleic estolide products with superior cold flow properties. Industrial Crops and Products. 182. Article 114857. https://doi.org/10.1016/j.indcrop.2022.114857.
