Estimated displaced products and ratios of distillers’ co-products from corn ethanol plants and the implications of lifecycle analysis

Abstract

Displacement of conventional animal feed components – corn, soybean meal and urea – by distillers’ co-products has been revisited. We developed the distillers’ co-products displacement ratios at different levels: the feedlot level, the US market level and the composite US and export market level, in order to provide a relevant estimate for ethanol plant operators, stakeholders and decision makers. As expected, corn is still the single largest component in the conventional beef cattle diet to be displaced by distillers’ co-products, followed by soybean meal. On average, 1 kg of wet distillers’ grains could displace 1.313 kg of corn and urea together, when it is used as a substitute in the diet of beef cattle; for distillers’ dried grain with solubles, 1.271 kg of corn and urea can be displaced per kg of distillers’ dried grain with solubles fed to beef cattle. Uncertainties about the consistency of reported data, export market and emerging new co-products are discussed. In addition, the use of distillers’ co-products as an animal feed may have an indirect impact on the lifecycle assessment of corn ethanol.

Acknowledgments

We thank Zia Haq of that DOE office for his support of this study.

Financial & competing interests disclosure

This study was supported by the US Department of Energy, Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Biomass Program, under contract DE-AC02–06CH11357. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.