Research Project: Enable New Marketable, Value-added Coproducts to Improve Biorefining Profitability

Location: Sustainable Biofuels and Co-products Research

2019 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 chemical modification of the branched-chain fatty acids. 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
Considerable progress was made on all objectives, all of which fall under National Program 306 – Product Quality and Uses, Component 3 - Biorefining. Objective 1: A GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transport) process and cost model was constructed to optimize and evaluate the fractionation of distillers milo oil. The model showed that the cost of extracting sorghum wax from intact sorghum kernels or from sorghum bran was probably not economically feasible. However, if distillers milo oil (or distillers oil from ethanol plants that utilize a blend of corn and sorghum) could be obtained at a cost similar to the current cost of distillers corn oil (~$0.35/lb), then it could potentially be possible to economically fractionate sorghum wax from these distillers oils, with yields ranging from 2 to 10 lbs of sorghum wax per 100 pounds of distillers oil. Objective 2a: The concept of using sorghum bran as a feedstock for combustion or fast pyrolysis was considered. However, our fractionation and analytical studies (Hums et al, 2018B) revealed that sorghum bran has a relatively high nutritive value (~10% protein, ~10% crude fat, and ~40% starch) and more profit can be obtained from sorghum brans by selling them for animal feed applications or for fractionating all or some of its components, such as sorghum wax, for nutraceutical or industrial application than for using them as feedstocks for combustion or fast pyrolysis. Objective 2b: Arabinoxylan (AX) from sorghum bran was isolated and tested to determine antioxidant properties. AX from sorghum bran had an improvement of 8% in oxygen radical scavenging assays over corn bran AX (cAX). Further characterization of the AX fractions showed that sorghum bran AX had a lower mass quantity of both ferulic and p-coumaric acid (0.532 mg/100 g AX) compared to cAX (1.66 mg/100 g AX). The better scavenging efficiency for sorghum bran AX may be reflected in the presence of other compounds aside from the hydroxy cinnamic acids located within the AX structure. Objective 3a: Sorghum bagasse and biomass arabinoxylan (AX) was isolated similarly to sorghum bran AX and utilized to determine relevant antioxidant properties. Sorghum biomass AX scavenging efficiency underperformed compared to sorghum bran AX, but sorghum bagasse AX had a 25% improvement in scavenging efficiency. The overall hydroxy cinnamic acids content of the sorghum bagasse AX was 13.15 mg/100 g AX, which indicates the greater presence of phenolic acids in the AX fraction can improve the overall antioxidant capacity. Prior work has also indicated that sorghum bagasse AX utilized to prepare films had poor quality due to extreme brittleness even with plasticizer addition. Conversely, sorghum bran AX films had superior quality in terms of strength and moisture barrier properties at low relative humidity. AX isolation and recovery from different sorghum fractions has shown that integration into biorefining processes is possible by determining end use applications. Sorghum bran AX has more useful functionality for biomaterial products, while AX from sorghum bagasse are more suited for food based applications as an additive. Objective 3b: Cellulose rich fraction (CRF) from sorghum bran (SBR), sorghum bagasse (SBA) and sorghum biomass (SBI) were isolated, characterized and their functionalities (water holding capacity and dietary fiber) were studied. They can hold water at 22.76 to 35.27 times their dry weight at room temperature, which is a very good property for their application in food products. All three CRF isolated from SBR, SBA and SBI sources were very rich in insoluble dietary fiber (IDF) containing 89.12, 97.01 and 87.89 % (w/w), respectively. The above two properties qualify them as good ingredients in many food products, which include: a. Bakery products, e. g. biscuits, buns, rolls, muffins, sweet breads, wheat rolls, cookies, brownies, cakes, bakery mixes, pie dough, pizza dough, pita bread, pie filling, tortillas, crackers, snack food; b. Dairy products, e.g. cream cheese, ricotta cheese, processed cheese, cheese sauces, sour cream, dips, ice cream, puddings, custards, whipped toppings, yogurt, yogurt drinks, smoothies; c. Meats, e.g. ground meat, ground meat patty, sausages, hot dogs, meat fillings, hamburger; and d. Dressing, e.g. mayo spread, salad dressings, dips, sauces, salsa, barbecue sauce, tomato sauce. This technology has been transferred to our CRADA partner. Objective 4a: Cold flow improvers, in the form of additive mixtures of branched chain alkyl esters in fatty acid methyl esters (biodiesels), only slightly improved the low temperature properties (i.e. cloud point, pour point, kinematic viscosity) of biodiesels made from lard, tallow and sewage scum grease. Results of the study indicated that process analysis was not necessary for this data set. Objective 4b: We continued to identify sulfur-bearing species in biodiesel produced from ‘brown’ greases such as ‘trap’ grease and float greases using modified state-of-the art analytical instrumentation and protocols. These brown greases have been collected from local municipal underground grease traps and waste water treatment plants at various times of the year. Techno-economic analysis will commence when the previous milestones are satisfactorily accomplished. Those milestones remain in the optimization phase. Objective 4c: We have improved the i.s.t. of the lipids in post-fermentation sorghum stillage (DDGS) by increasing conversion of the lipids in sorghum DDGS to biodiesel from approximately 30% to greater than 70% as a result of feedstock pretreatment. Co-product meals are being collected for evaluation. There is no collaborator pilot plant for this project. The designated collaborator provided insufficient substrate for this study. Therefore, we had to continue the work internally with ARS scientists who could provide adequate substrate. If necessary, techno-economic analysis will commence when the previous milestones are satisfactorily accomplished. Those milestones remain in the optimization phase. Objective 5a: A scale-up process designed according to the laboratory size data was successfully developed to produce the targeted alkyl-branched fatty acids (i.e., isostearic acid). This process can produce a large volume of the materials per batch and only involves the starting refined oil feedstock, solid catalyst and cocatalyst, and a small amount of water. The solid catalyst can be easily removed by filtration and can be recycled and reused for at least up to 20 times. Efforts were made to integrate the technology to end users (e.g., Arizona Chemical currently known as Kraton) and products were sent for evaluation. However, from industry feedback, even though this process can utilize existing capital to produce the products, it is still not economically feasible compared to existing plants where isostearic acids are produced from less refined oils. Objective 5b: A scale-up process to produce the aryl-branched fatty acids (i.e., phenolic-branched-chain fatty acids) was successfully developed by utilizing a similar reactor design concept as to the isostearic acid process. The solid catalyst can also be recycled and reused for at least 10 times to reduce cost and waste. This process also involves phenolic reagents, which are used in excess and can be very expensive; therefore, research efforts were made to recycle these materials. The products are currently being evaluated by an industrial partner (Colgate Palmolive Inc.) in their antimicrobial applications.

Accomplishments

Review Publications
Moreau, R.A., Harron, A.F., Hoyt, J.L., Powell, M.J., Hums, M.E. 2018. Analysis of wax esters in seven commercial waxes using C30 reverse phase HPLC. Journal of Liquid Chromatography and Related Technologies. 41(10):604-611. https://doi.org/10.1080/10826076.2018.1485036.
Mendez-Encinas, M.A., Carvajal-Millan, E., Yadav, M.P., Kale, M., López-Franco, Y., Rascon-Chu, A., Lizardi-Mendoza, J., Brown-Bojorquez, F., Silva-Campa, E., Pedroza-Montero, M. 2019. Partial removal of protein associated with arabinoxylans: impact on the viscoelasticity, crosslinking content and microstructure of the gels formed. Journal of Applied Polymer Science. 47300:1-10.
Li, J., Yadav, M.P., Zhu, Y., Li, J. 2019. Effect of different hydrocolloids with gluten proteins, starch and dough microstructure. Journal of Cereal Science. 87:85-90. https://doi.org/10.1016/j.jcs.2019.03.004.
Zhang, J., Yadav, M.P., Li, J. 2019. Biodegradability and biodegradation pathway of di-(2-ethylhexyl) phthalate by Burkholderia pyrrocinia B1213*. Chemosphere. 225:443-450. https://doi.org/10.1016/j.chemosphere.2019.02.194.
Stoklosa, R.J., Latona, R.J., Yadav, M.P., Bonnaillie, L. 2019. Evaluation of arabinoxylan isolated from sorghum bran, biomass, and bagasse for film formation. Carbohydrate Polymers. 213:382-392. https://doi.org/10.1016/j.carbpol.2019.03.018.
Bhinder, S., Kaur, A., Singh, B., Kaur, M., Kumari, S., Singh, N., Yadav, M.P. 2019. Effect of infrared roasting on antioxidant activity, phenolic composition and maillard reaction products of tartary buckwheat varieties. Food Chemistry. 285:240-251. https://doi.org/10.1016/j.foodchem.2019.01.141.
Hums, M.E., Moreau, R.A., Powell, M.J., Hoyt, J.L. 2018. Extraction of surface wax from whole grain sorghum. Journal of the American Oil Chemists' Society. 95:845-852. https://doi.org/10.1002/aocs.12088.
Hums, M.E., Moreau, R.A., Yadav, M.P., Powell, M.J., Simon, S. 2018. Comparison of bench-scale decortication devices to fractionate bran from sorghum. Cereal Chemistry. 95:720-733. https://doi.org/10.1002/cche.10087.
Zhang, J., Uknalis, J., Moreau, R.A., Lew, H.N. 2019. Development of magnesium oxide-zeolite catalysts for isomerization of fatty acids. Catalysis Letters. 149:303-312. https://doi.org/10.1007/s10562-018-2601-3.
Lew, H.N., Wagner, K., Zhang, J., Nunez, A., Fan, X., Moreau, R.A. 2018. New classes of antimicrobials: poly-phenolic branch-chained fatty acids. Natural and Bio-Based Antimicrobials for Food Application. ACS Symposium Series: American Chemical Society: Washington DC, 2018. 209-221.
Jones, P.J., Shamloo, M., Mackay, D.S., Rideout, T.C., Myrie, S., Plat, J., Roullet, J., Baer, D.J., Calkins, K., Davis, H. Duell, B., Ginsberg, H., Gylling, H., Jenkins, D., Lütjohann, D., Moghadasian, M., Moreau, R.A., Mymin, D., Ostlund, R., Ras, R., Reparaz, J., Trautwein, E., Turley, S., Vanmierlo, T., Weingärtner, O. 2018. Progress and perspectives in plant sterol and plant stanol research. Nutrition Reviews. 76:725-745. https://doi.org/10.1093/nutrit/nuy032.
Wyatt, V.T., Boakye, P.G., Jones, K.C., Latona, N.P., Liu, C., Strahan, G.D., Zhang, J., Besong, S.A., Lumor, S.E. 2019. Synthesis of absorbent polymer films made from fatty acid methyl esters, glycerol, and glutaric acid: thermal, mechanical, and porosity analysis. Journal of Applied Polymer Science. 1-15. https://doi.org/10.1002/app.47822.
Suri, K., Singh, B., Kaur, A., Yadav, M.P., Singh, N. 2019. Impact of infrared and dry air roasting on the oxidative stability, fatty acid composition, Maillard reaction products and other chemical properties of black cumin (Nigella sativa L.) seed oil. Food Chemistry. 295:537-547. https://doi.org/10.1016/j.foodchem.2019.05.140.
Kaur, A., Yadav, M.P., Singh, B., Bhinder, S., Simon, S., Singh, N. 2019. Isolation and characterization of arabinoxylans from wheat bran and study of their contribution to wheat flour dough rheology. Carbohydrate Polymers. 221:166-173. https://doi.org/10.1016/j.carbpol.2019.06.002.
Liu, Y., Yadav, M.P., Yin, L. 2017. Enzymatically catalyzed corn fiber gum-bovine serum albumin conjugates: their interfacial adsorption behaviors in oil-in-water emulsions. Food Hydrocolloids. 77:986-994. https://doi.org/10.1016/j.foodhyd.2017.11.048.