IMPROVING THE VALUE AND UTILIZATION OF ETHANOL MANUFACTURING CO-PRODUCTS
Location: North Central Agricultural Research Laboratory
Project Number: 5447-41000-003-00
Start Date: Nov 03, 2009
End Date: Mar 31, 2011
Objective 1: Develop new technologies to improve storability and flowability behavior of distillers dried grains with solubles (DDGS) and distillers wet grains (DWG) and that enable new, commercially-preferred methods for storage and transport of these coproducts.
Objective 1.1: Identify, characterize, and quantify physical and chemical properties, and their interactions with environmental factors, that impact material handling and storability behavior of DDGS.
Objective 1.2: Identify, characterize, and quantify physical and chemical properties, and their interactions with environmental factors, that impact material handling and storability behavior of DWG.
Objective 2: Develop technologies that enable commercially-preferred processes for converting distillers grains of inconsistent composition and quality into value-added feed materials, particularly 100% DDGS pellets and balanced aquaculture rations.
Objective 2.1: Scale-up and demonstrate the commercial feasibility of using 100% pelleted DDGS in dairy cattle feeding.
Objective 2.2: Scale-up and demonstrate the commercial feasibility of using DDGS as a protein source for nutritionally-balanced aquaculture feeds.
Objective 3: Develop commercially-viable human food ingredients based on DDGS.
As the ethanol industry grows, the supply of coproducts will also grow. Livestock producers want cheaper feeds; but the ethanol industry is not sustainable if the feeds are too inexpensive. The ultimate, unifying goals of this project are to augment current uses, and to develop new market opportunities for distillers grains, and thus simultaneously bolster the economic viability of the fuel ethanol industry as well as the livestock industry, by facilitating the use of these feed materials. Each of the research components is thus integral to attaining this goal. The first objective focuses on storage and handling issues, while the second and third objectives target value-added processing and utilization. Each of these must be addressed in order to successfully improve the use of these processing residues.
The aim of the first portion of the project is to identify and quantify the primary factors and interactions that affect flowability, handling, and storage behavior of ethanol coproducts (including distillers dried grains with solubles (DDGS) and distillers wet grains (DWG)), especially those that result in poor coproduct flowability. Independent variables that will be controlled include composition (including moisture content, lipid content, residual starch content, etc. – by varying the ratio of CDS/DWG in the DDGS), and storage and handling conditions (including storage time, consolidation pressure, temperature, and humidity). Dependent variables include material handling characteristics and flowability behavior, as quantified by physical properties and Jenike and Carr Indices. Practical industrial practices and/or remediation strategies (i.e., altering coproduct processing conditions, modifying storage conditions, using flow agents, or other measures) will be identified, investigated, and developed for use at commercial operations.
The aim of the second portion of the research is to develop pelleted distillers grains-based feed products that can be used for traditional livestock (i.e., beef, dairy, swine, poultry), or new target species (such as fish). Pelleted products will be developed (in close collaboration with SDSU animal nutritionists) via pellet mill processing and extrusion processing using DDGS as a protein source. Advantages to pelleting of feed can include nutrient-densification, better palatability, improved nutrient availability as a result of cooking that occurs during processing, and improved storability and flowability behavior. Thus these pelleted feed products will have intrinsic values higher than currently-available distillers grains, which are stored, shipped, and fed as-is in loose, granular bulk form.
The aim of the third portion of the research is to develop food products from distillers grains for human consumption. High-fiber, high-protein, low-starch DDGS-based flour will be developed by fractionating distillers grains in order to concentrate various nutrient streams; specific fractions will then be selected for further processing (which may include milling, bleaching, deodorizing, sterilizing, etc.), after which they will be incorporated into various ingredient matrices for baking and subsequent product testing. Ingredient functionality and nutritional assessment will be conducted to determine if these materials are viable for use in human foods, and if, by increasing the protein and fiber contents, either improved food products or new foods can be developed based on DDGS. These novel products will provide new utilization avenues for ethanol coproducts.