Location: Sustainable Biofuels and Co-products Research
2015 Annual Report
Objectives
1. Develop processes to fractionate sorghum and corn/sorghum oils into new commercially-viable coproducts.
2. Develop processes to fractionate grain-derived brans into new commercially-viable coproducts.
2a: Develop processes to fractionate grain-derived brans into new commercially-viable coproducts such as lipid-based coproducts and for other industrial uses such as extrusion or producing energy or fuel.
2b: Develop commercially-viable, value-added carbohydrate based co-products from sorghum brans and the brans derived from other grains during their biorefinery process.
3. Develop processes to fractionate biorefinery-derived celluloses and hemicelluloses into new commercially-viable coproducts.
3a: Develop commercially-viable, value-added hemicellulose based co-products from sorghum biomass, sorghum bagasse and other agricultural based biomasses produced during their biorefining.
3b: Develop commercially-viable, value-added cellulose based co-products from sorghum biomass, sorghum bagasse and other agricultural based biomasses produced during their biorefining.
4. Develop technologies that enhance biodiesel quality so as to enable greater market supply and demand for biodiesel fuels and >B5 blends in particular.
4a: Improve the low temperature operability of biodiesel by (1) chemical modification of the branched-chain fatty acids and (2) reduce levels of contaminants that block fuel filters (e.g., sterol glucosides and saturated monoglycerides).
4b: Develop technologies that significantly reduce quality-related limitations to market growth of biodiesel produced from trap and float greases.
4c: Further develop direct (in situ) biodiesel production so as to enable its commercial deployment.
5. Develop technologies that enable the commercial production of new products and coproducts at lipid-based biorefineries.
5a: Enable the commercial production of alkyl-branched from agricultural products and food-wastes.
5b: Enable the commercial production of aryl-branched fatty acids produced from a combination of lipids and natural antimicrobials possessing phenol functionalities.
Approach
In conjunction with CRADA partners and other collaborators, develop technologies that identify new biorefinery coproducts, evaluate their applications and estimate their profitability and marketability. The approach will focus on development processes to produce several types of new coproducts. First, processes will be developed to extract and fractionate sorghum oil from sorghum kernels and sorghum bran. Processes will also be developed to extract and fractionated cellulose-rich and hemicellulose-rich fractions from sorghum kernels, sorghum bran, sorghum bagasse, and biomass sorghum. Other processes will be developed to improve the biofuel value of biodiesel by blending biodiesel with modified fatty acid derivatives to enhance its low temperature performance, reduce the levels of impurities that block fuel lines, economically convert trap grease and float grease to biodiesel, and improve the in situ process to make biodiesel directly from oil-rich low value agricultural products. In addition to biodiesel applications, other processes will be developed to produce branched fatty acids with unique functional (including improved lubricity) and biological properties (including antimicrobial and antioxidant properties).
Progress Report
Objective 1. Numerous samples of modern grain sorghum hybrids have been obtained. Oil, carotenoids, and waxes have been extracted and yields of all three have been compared using several different types of extraction. A new HPLC (high performance liquid chromatography) method to analyze sorghum waxes and carotenoids was developed. Methods were developed to fractionate sorghum oil into fractions that are enriched in waxes and carotenoids.
Objective 2. Samples of several sorghum hybrids were decorticated using a pearler and a scarifier and the resulting bran fractions were extracted and compared. Developed a process to produce of arabinoxylans (AX) and cellulose rich fractions (CRF) from brans obtained from sorghum and other grains.
Objective 3. Developed a process to produce arabinoxylan (AX) from sorghum biomass, sorghum bagasse and other agricultural based biomasses. Developed a process to produce a cellulose rich fraction (CRF) from sorghum biomass, sorghum bagasse and other agricultural based biomasses.
Objective 4. In collaboration with the ARS scientist from National Center for Agricultural Utilization Research (NCAUR), a series of isostearate bulky ester derivatives were synthesized and their low temperature properties were evaluated. Introduction of bulky functional groups to the isostearic acid head is the most direct way to create fatty acids with low melting points with enhanced fluidity. Three new ester derivatives were synthesized from the isostearic acids using the esterification method, which is an efficient method for converting fatty acids to fatty acid esters in the presence of liquid acids (i.e., sulfuric acid, phosphoric acid, hydrochloric acid) and alcohols. This research was completed and the results showed that these synthesized esters have much better low melting points than the original fatty acids. We have made progress in sub objectives. Those include work to reduce the level of contaminants that block fuel filters by the formation of solids at or below the cloud point and to reduce sulfur content in biodiesel below 15 ppm. Solids that form in a diesel fuel can block fuel filters, resulting in engine failure due to fuel starvation. We have recently addressed this problem by attempting to depolymerize lignin into a biodiesel-soluble additive that will reduce the CP of biodiesel. Among potential new feedstocks are the ‘brown’ or ‘trap’ greases collected from commercial food preparation facilities. However, recent attempts to market biodiesel from these feedstocks have failed due to the inability to reduce the sulfur content of the product below 15 ppm. In collaboration with Drexel University, we have been able to successfully reduce the sulfur content to desirable levels. Work to ensure reproducibility and to extend the technology to float greases are currently underway.
Objective 5. With the support from a NIFA-AFRI funded project, entitled “Development of Environmentally Friendly and Economically Feasible Engineering Processes for High-Value Biobased Products”, ARS scientists found a zeolite-Lewis base additive combination catalyst system which could efficiently produce the isostearic acid products at excellent yields. Without the Lewis base additives, the resulting products contain greater amounts of unwanted polymeric byproducts. To broaden the utility of the catalytic system, nonfood use feedstocks were used to make these isostearic acid products. However, since these products were much more complex, continued research efforts were needed at the analysis stage in order to efficiently characterize the isostearic acid products. Phenolics such as cinnamaldehyde, thymol and carvacrol have strong antimicrobial properties, but they possess unpleasant characteristic odors which prevent their use in the food industry. The research project focused on producing phenolic fatty acid compounds which mimic the existing phenolics but without the unpleasant odors. These compounds were made from two streams of natural materials. This reaction system showed that it was capable of producing the desired phenolic fatty acid compounds. Analytical methods to characterize the products were developed.
Accomplishments
Review Publications
Dunn, R.O., Lew, H.N., Haas, M.J. 2015. Branched-chain fatty acid methyl esters as cold flow improvers for biodiesel. Journal of the American Oil Chemists' Society. 92(6):853-869. DOI: 10.1007/s11746-015-2643-2.
Lew, H.N. 2015. Lewis base additives improve the zeolite ferrierite-catalyzed synthesis of isostearic acid. Journal of the American Oil Chemists' Society. 92:613-619.
Yadav, M.P., Hicks, K.B., Johnston, D., Hotchkiss, A.T., Chau, H.K., Hanah, K. 2015. Production of bio-based fiber gums from the waste streams resulting from the commercial processing of corn bran and oat hulls. Food Hydrocolloids Journal. DOI: 10.1016/j.foodhy.2015.02.017.
Liu, Y., Qiu, S., Li, J., Chen, H., Tatsumi, E., Yadav, M.P., Yin, L. 2014. Peroxidase mediated conjugation of corn fibeer gum and bovine serum albumin to improve emulsifying properties. Carbohydrate Polymers. 118:70-78.
Brooks, W.S., Vaughn, M.E., Berger, G.L., Griffey, C.A., Thomason, W.E., Pitman, R.M., Malla, S., Seago, J.E., Dunaway, D.W., Hokanson, E.G., Behl, H.D., Beahm, B.R., Schmale, D.G., Mcmaster, N., Hardiman, T., Custis, J.T., Starner, D.E., Gulick, S.A., Ashburn, S.R., Jones, E.H., Marshall, D.S., Fountain, M.O., Tuong, T.D., Kurantz, M.J., Moreau, R.A., Hicks, K.B. 2014. Registration of ‘Atlantic’ winter barley. Journal of Plant Registrations. 8:231-236.
Moreau, R.A. 2015. Composition of plant sterols and stanols in supplemented food products. Journal of AOAC International. 98:670-685.
Wyatt, V.T. 2014. The effects of solvent polarity and pKa on the absorption of solvents into poly(glutaric acid-glycerol) films. Journal of Applied Polymer Science. 131(13):40434-40440.
Kale, M.S., Yadav, M.P., Hicks, K.B., Hanah, K. 2015. Concentration and shear rate dependence of solution viscosity for arabinoxylans from different sources. Food Hydrocolloids Journal. 47:178-183.
