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ARS Home » Northeast Area » Wyndmoor, Pennsylvania » Eastern Regional Research Center » Sustainable Biofuels and Co-products Research » Research » Publications at this Location » Publication #377122
Title: Impact of mixing grain sorghum with corn on ethanol and coproduct yields

Author
item Johnston, David
item Stoklosa, Ryan
item Yee, Winnie

Submitted to: Biofuels, Bioproducts, & Biorefining (Biofpr)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/2024
Publication Date: 7/26/2024
Citation: Johnston, D., Stoklosa, R.J., Yee, W.C. 2024. Impact of mixing grain sorghum with corn on ethanol and coproduct yields. Biofuels, Bioproducts, & Biorefining (Biofpr). 18:1930-1939. https://doi.org/10.1002/bbb.2666.
DOI: https://doi.org/10.1002/bbb.2666

Interpretive Summary: Current ethanol production facilities utilize almost exclusively corn for production. Some of these facilities have surplus capacity that could be utilized if there was additional demand. Using alternative feedstocks for existing facilities rather than building new dedicated facilities could provide significant benefits and cost savings. Grain sorghum is a feedstock with a similar composition to corn that could potentially be utilized at significant incorporation levels in existing facilities with minimal or no modifications but is currently only minimally utilized. To better understand the impact of grain sorghum incorporation, we studied mixed corn and grain sorghum fermentations at the laboratory scale and utilized the data generated to aid in the development of process and economic models at full scale production. The results showed that grain sorghum could be utilized with little to no process modifications. Additionally, the animal feed coproduct could potentially be more valuable due to the increase protein content. This information will be useful to ethanol producers as well as others studying the fuel ethanol process.

Technical Abstract: Existing corn ethanol biorefineries produce about 94% of the ethanol capacity in the United States and currently have surplus production capacity. Expanding feedstocks for existing facilities rather than building new dedicated facilities could provide significant benefits and cost savings. Grain sorghum is a feedstock with a similar composition to corn that could potentially be utilized at significant incorporation levels in existing facilities with minimal or no modifications but is currently only minimally utilized. To better understand the impact of grain sorghum incorporation, we studied mixed corn and grain sorghum fermentations at the laboratory scale and utilized the data generated to develop technical models for each at 119 million kg/year (40 million gal/year). Detailed processing and economic comparisons were developed to determine the overall impact. Results showed significant feedstock savings ($8 million/year) potential for utilization of sorghum relative to corn. Ethanol production cost was reduced by $0.07 per kg of ethanol using sorghum relative to corn. Other potential impacts on coproduct composition and values were also determined and discussed.