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United States Department of Agriculture

Agricultural Research Service

Research Project: ECONOMIC COMPETITIVENESS OF RENEWABLE FUELS DERIVED FROM GRAINS AND RELATED BIOMASS

Location: Sustainable Biofuels and Co-Products

2009 Annual Report


1a.Objectives (from AD-416)
Lower the cost of fuel ethanol production from corn and barley through improved dry grind and dry milling fractionation techniques, including a new 'ammoniation' process. Develop more efficient processes for converting hulled and hulless barley to fuel ethanol and improved, beta-glucan-free, feed coproducts. Through research assist in creation of a new hulless barley-to-ethanol industry in corn deficient regions, particularly the Mid Atlantic States and the North Western U.S. Use the low-starch ('low carb') and high-fiber, high-oil, and high-protein fractions recovered from corn and barley prior to ethanol fermentation to produce health-promoting food ingredients, functional foods, and extruded snacks. Develop improved processes to convert low valued crop-related biomass, byproducts and energy crops being researched in the ARS energy crop program into renewable hydrogen or liquid fuels and conduct economic feasibility studies for integrating this technology into co-located dry grind ethanol plants. Develop small-scale thermo-chemical technologies that economically, efficiently, and sustainably produce hydrogen and coproducts from agricultural materials.


1b.Approach (from AD-416)
Develop a continuous corn ammoniator for improving the conversion of corn to fuel ethanol. Conduct research to develop new dry de-germinators, roller mills, and associated fractionation devices with and without 'ammoniation' as a 'front end' to the traditional dry grind ethanol process. Use these techniques on corn and hulled barley to produce high-starch fractions for more efficient fermentations, and low-starch fractions that can be used as value added health-promoting 'low-carb' food ingredients, healthy edible oils and nutraceuticals. Use newly developed hulless barley cultivars and develop new beta-glucan-degrading enzyme technology to reduce fermentation viscosity and improve the production of ethanol from barley. Prepare hulless barley DDGS from beta-glucanase treated fermentations and examine as high-valued feeds for non-ruminants and aquaculture. Low-valued barley hulls and corn bran from corn and barley ethanol processing and energy crops and residues like switch grass, Eastern gama grass, reed canary grass, alfalfa, and corn stover will be studied as substrates for conversion to hydrogen and related liquid and gaseous fuels by thermochemical processes in a pyrolyzer (pyroprobe) coupled to a gas chromatograph/mass-spectrometer (PY-GC/MS) to analyze gasification products. Promising substrates will be converted in a 2-inch bench-top fluidized-bed reactor to test selected feedstock for yields of H2, syngas, char and pyrolytic oil. Process modeling and economic analysis will be conducted on all the technologies studied, to help direct research toward the most fruitful and commercially feasible areas.


3.Progress Report
Evaluation of new Barley Cultivars for their Fermentability and for their Content of Valuable Coproducts – We established collaborations with ARS barley breeders at Aberdeen, ID and cereal chemists in Uppsala, Sweden. We are in the process of screening several new barley cultivars of hulled and hulless barley to evaluate the total fermentability (total yields of ethanol per bushel by fermentation of both starch and beta-glucans) and the total levels of valuable functional lipid coproducts (including phytosterols, tocopherols, tocotrienols, alkylresorcinols, arbutins, and other antioxidants). This information will be useful to our CRADA partner and to other US ethanol plants that are considering using winter barley as a fuel ethanol feedstock, to enable them to select barley cultivars that have the highest ethanol yields and cultivars that produce the most valuable coproducts.

Considerable time was spent during this year in creating and developing an Aspen plus® computer model of biomass pyrolysis. The model was adjusted to agree with published data from experimental pyrolysis of three feedstocks, switchgrass and alfalfa harvested at the “early bud” or “full flower” stage of maturity. The model used the high heating values (HHV) of the feed and products to calculate the exothermic or endothermic heat of reaction. This model is necessary to understand the energy and material balances in the pyrolysis process. Once this is done, it will be possible to use this model to guide our research efforts to reduce energy usage or improve product yields and quality.

We have begun to improve the barley EDGE process for making fuel ethanol from winter energy barley. While the old process is effective, a more efficient process could save additional money and energy. We are developing a pre-treatment process for barley grain that should make its conversion to fuel ethanol use less energy and water. Experiments are being done to find the best temperature and enzyme combinations to get the highest ethanol yields.

Our CRADA partner is building the first winter barley ethanol plant in the United States using our EDGE process. Area farmers are raising barley this year to prepare for the plant's commissioning. This year has been a record year for rainfall and area barley has been infected heavily with fusarium head blight and the mycotoxin, DON. We are beginning studies to see if we can remove DON from barley by dehulling and by use of other pre-treatment procedures. A USDA AFRI grant was written and submitted to fully fund this work.


4.Accomplishments
1. Landmark study shows that corn ethanol is more efficient and cost effective than ever. In conjunction with partners at the Copernicus Laboratory of the University of Utrecht, the Netherlands, we conducted a comprehensive study of the fuel ethanol industry in the US from 1985 until 2005. We tracked the cost of production of corn, the primary feedstock, the amount of energy and the operating costs in constant dollars. What we found was that corn production costs in the US declined by 62% over these 20 years due to better production methods and improved yields. We also found that processing costs for conversion of corn to ethanol declined by 45% from 1983-2005 and the total costs of production (including capital and net corn costs) declined approximately 60% during this period. Energy costs also decreased approximately 50% over this period despite increasing costs of energy. This is due to the development of improved energy-saving technology by the industry. By examining the trends in costs and energy use, it is proposed that corn ethanol production is not a "mature" technology and that the efficiency and energy balance will continue to improve as time goes on. This information is now available for all to use to determine the true cost and energy balance of US ethanol production. It should be useful to those in industry, government, and universities who are studying the economics and sustainability of fuel ethanol.

2. New Magnetic Resonance Method Determines Quality of Bio-oil. A new NMR-based methodology was developed to characterize the chemical composition and chemical functionality of bio-oils produced from pyrolysis of various agricultural residues. Determining this chemical composition is critical to optimizing these increasingly important fuel intermediates. This work will be of great value to those trying to make advanced biofuels from non-food feedstocks. A reviewer of this work said "This manuscript [Mullen, et al. Energy & Fuels, 23: 2707-2718 (2009)] provides the single most valuable paper on bio-oil nmr characterization (how to do it right) that is currently available."

3. Guayule byproducts can be used as a feedstock for advanced biofuels. We successfully produced energy-dense liquid fuel intermediates from guayule bagasse, a byproduct from domestic natural rubber production. Guayule is a desert plant used for the production of latex rubber however only 10% is used with 90% wasted. We produced a high-BTU fuel that can provide needed energy for latex processing plants and improve the economics of the industry. The result was published in the Journal of Fuel and was also part of a feature article in Agricultural Research Magazine. The work will benefit all processors of guayule latex who wish to decrease carbon emissions and become energy independent.

4. Pennycress processing byproduct used to make landmark quality bio-oil. Produced stable pyrolysis bio-oil from pennycress presscake. Pennycress seed is a member of the mustard family grown for its oil that is used in biodiesel production in the US. The presscake left after extraction of the oil used for biodiesel has no use as animal feed because it is toxic. We successfully produced pyrolysis bio-oil from the cake and found it to be unique for its low oxygen and acid contents thereby making it stable, with superior storage life unlike bio-oils produced from any other biomass thus far. A patent disclosure has been filed.

5. identified new catalysts to upgrade crude bio-oil for refining into green gasoline and diesel. We investigated the use and impact of certain zeolite catalysts on lignin derived from several sources and verified that non-oxygen containing aromatic hydrocarbons can be produced by pyrolysis with quantities depending on the lignin variety and composition. This information will be important to those in the paper, pulp and cellulosic ethanol industries looking for ways to utilize lignin co-products.


6.Technology Transfer

Number of Active CRADAs2
Number of the New/Active MTAs (providing only)2
Number of Invention Disclosures Submitted2
Number of Other Technology Transfer2

Review Publications
Taylor, F., Kim, T., Abbas, C.A., Hicks, K.B. 2008. Liquefaction, Saccharification, and Fermentation of Ammoniated Corn to ethanol. Biotechnology Progress. 24:1267-1271.

Boateng, A.A. Response of the devolatilization process to the lignin concenration in alfalfa stems. 2009. Energy and Fuels. 23:2316-2318.

Kim, T., Nghiem, N.P., Hicks, K.B. 2009. Pretreatment and fractionation of corn stover by S.E.A.A.(Soaking in ethanol and aqueous ammonia). Applied Biochemistry and Biotechnology. 153:171-179.

Simkovic, I., Yadav, M.P., Zalibera, M., Hicks, K.B. 2009. Chemical modification of corn fiber with ion-exchanging groups. Carbohydrate Polymers. 76:250-254.

Mullen, C.A., Strahan, G.D., Boateng, A.A. 2009. Characterization of various fast pyrolysis bio-oils by NMR spectroscopy. Energy and Fuels. 23:2707-2718.

Boateng, A.A., Mullen, C.A., Goldberg, N.M., Hicks, K.B., Mcmahan, C.M., Whalen, M.C., Cornish, K. 2009. Energy-dense liquid fuel intermediates by pyrolysis of guayule (Parthenium argentatum) shrub and bagasse. Fuel. 88:2207-2215.

Liu, K., Moreau, R.A. 2008. Concentrations of functional lipids in abraded fractions of hulless barley and effect of storage. Journal of Food Science. 73(7):C569-C576.

Moreau, R.A. 2009. Barley Oil. In: Moreau, R.A., Kamal-Eldin, A., editors. Gourmet and Health-Promoting Specialty Oils. Urbana: AOCS Press. p. 455-478.

Hettinga, W.G., Junginger, H.M., Dekker, S.C., Hoogwijk, M., Mcaloon, A.J., Hicks, K.B. 2009. Understanding the reductions in US corn ethanol production costs: an experience curve approach. Energy Policy. 37:190-203.

Last Modified: 9/22/2014
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