|O Brien, Dennis|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/2004
Publication Date: 5/20/2004
Citation: Hicks, K.B., Taylor, F., Kohout, K.M., Kurantz, M.J., Thomas, J.L., O Brien, D.J., Johnston, D., Flores, R.A., Moreau, R.A., Hoot, L. Developing barley as a major feedstock for fuel ethanol production. Meeting Abstract 2004. International Fuel Ethanol Workshop & Trade Show. Madison, WI., June 22-25. Session 7: Feedstocks for Ethanol Production (1).
Technical Abstract: The growing need for domestic energy independence and a proposed National Renewable Fuels Standard has led to a major expansion of domestic fuel ethanol production. Over 90% of fuel ethanol is made today from corn and approximately 10% of the US crop goes for this use alone. While this has benefited corn producers, a projected need to further increase production will put stresses on corn supplies. Producers from non-corn belt areas also need new markets for grains they can grow in order to increase farm income. Many of these farmers can grow winter or spring barley, which can be used as a feedstock for ethanol. However, conversion of traditional hulled barley to fuel ethanol in a conventional corn-to-ethanol process is problematic and not cost competitive. The abrasive nature of hulled barley, the high viscosity of barley fermentations, the low starch and high fiber content produce low ethanol yields and a poor quality DDGS. To solve these problems, we have now begun a research initiative that includes these goals: 1. Develop optimized cultivars of barley, especially hulless varieties, that can be used as efficiently as corn for the production of fuel ethanol. 2. Develop new cost-effective technologies to convert barley into fuel ethanol, which include pre-fermentation fractionation technologies to increase starch content and new enzymatic processes to eliminate beta glucan viscosity while increasing ethanol yield. 3. Develop new high-valued coproducts including nutraceuticals and high-protein beta glucan-free DDGS suitable for high-valued poultry and swine feed markets. In the first research area above, we have now studied the composition of 116 traditional and new cultivars of winter hulled and hulless barley developed and grown in 2001/2002 as potential fuel ethanol feedstocks. Starch, protein, lipid, beta glucan, and moisture were measured. Experimental hulled varieties averaged 57% starch with some elite varieties reaching 65%. Experimental hulless varieties had a mean of 60% starch with the best cultivars exceeding 64%. Protein values for all cultivars ranged from 8.9% to 15.8%. Lipid content for hulless varieties (mean of 2.74%) were higher than for hulled varieties (2.28%). Beta glucan content were similar for hulled and hulless varieties (mean of about 4.7%, values ranging from 3.6 to 6.3%). In the second research area above, we compared a typical hulled winter barley grown in Maryland in 2001/02 to a new hulless variety, 'Doyce', grown during the same season, as fuel ethanol feedstocks. Doyce initially contained 59% starch, 12.8% protein, and 3.3% beta glucan. The control hulled barley contained 50% starch, 10% protein, and 2.9% beta glucan. Each barley sample (7.5 lb) was ground, mashed, and fermented using traditional processes and enzymes used for corn fermentations. Starch was quantitatively converted in each case. Ethanol yields ~17% higher were observed for Doyce. The DDGS produced from Doyce contained 29.9% protein compared to 22.6% for the hulled variety. Beta glucan levels were 7.4% in both DDGS samples. These preliminary data from one set of samples show that 'Doyce' would be favored to the hulled variety for fuel ethanol production. Studies in problem area 3 above are showing that commercial enzymes can be used to reduce beta glucan in barley DDGS and increase ethanol production by 2-4%. A wide variety of effectiveness was seen from enzymes from various commercial sources. In view of these studies, continued research in this area should lead to advances in the use of barley for fuel ethanol production.