Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/23/2005
Publication Date: 3/5/2006
Citation: Rosentrater, K.A. 2006. Ethanol processing coproducts - current constraints and future directions. Bioenergy-I: from Concept to Commercial Process Conference, Tomar, Portugal, March 5-10, 2006. Interpretive Summary:
Technical Abstract: The production of corn-based ethanol in the U.S. is dramatically increasing, and consequently, so is the quantity of coproducts generated from this processing sector. Sales of these streams provide a substantial revenue source and significantly increase the profitability of the production process. As the industry continues to expand, it is imperative to find new outlets for these coproducts, in order to maintain economic viability. Currently, the industry’s only outlet for the nonfermentable residues from the manufacturing process, primarily in the form of distillers dried grains with solubles (DDGS), and to a lesser degree in the form of distillers dried grains without solubles (DDG) and wet distillers grains (WDG), has been utilization as livestock feeds. Feeding to animals is a viable method for utilizing these byproducts because they contain high nutrient levels. Numerous research studies have been conducted to optimize their use in livestock rations. Even so, much work remains in order to improve and maximize their utilization in animal feeds. But, the industry needs a diversified utilization strategy, because this unidirectional approach may not prove sustainable. Distillers grains have much potential for value-added processing and utilization in other sectors, but barriers currently exist to their utilization. Physical, nutritional, and chemical properties are needed for the proper design of processing operations and byproduct applications, but have not been investigated comprehensively. Additionally, product flowability in storage and transport can be a problem. Several studies have examined the possibility of utilizing these materials in human foods as functional ingredients. But no food products are currently commercially available; for viable products to be successfully manufactured and marketed, additional research is needed. Further, initial trials have been conducted using these byproducts as soil amendments and fertilizers, incorporating them into plastic composites, extracting industrial components and chemicals, and extrusion processing. Recently, much research has targeted process modification, including corn fractionation, new enzymes, and other novel practices, in order to increase efficiencies and reduce quantity of coproducts. If these changes are commercially implemented, drastic reductions in the generated residues can be realized. Additionally, physical, chemical, and functional properties of these resultant streams may be considerably altered, which could affect utilization. Because of these issues, the thrust of this project is twofold: 1) to quantify physical and chemical properties of distillers grains; and 2) to develop value-added feeds, foods, and industrial materials from these coproducts. This project has three specific research objectives: 1) identify, characterize, and quantify specific physical and chemical properties that can be utilized or altered to improve storability and flowability behavior; 2) develop and evaluate improved processes for converting distillers grains into value-added feed materials; and 3) develop and evaluate processes for converting distillers grains into value-added food and industrial products. Attaining these objectives will provide ethanol processors with new and refined methods for storing and handling distillers grains. Additionally, new market opportunities will be identified and developed. Many potential applications for value-added use outside the livestock arena exist for distillers grains. Most of these avenues, however, are still in their infancy, but profound benefits will be realized when they are achieved, scaled-up, and deployed commercially.