The project will involve the implementation of technologies at full scale at the prototype dairy farm, Maple Leaf Dairy, and will utilize Soil Net’sinnovative, proprietary (patented), polymer-based technologies that enable cost-effective separation (“fractionation”) of dairy manure and associated bioenergy co-products: ethanol, vegetable oil / meals, biodiesel, and organic soil amendments such as mulches, and customized fertilizer nutrients. Importantly, these polymer-based technologies have been shown to provide cost-effective separation solutions at smaller scale than many extant separation technologies. The process / flow diagram at right shows the major components of the system that is being constructed and evaluated, and comprises five major interacting components: (1) Crop System, (2) Manure Processing, (3) Biogas, (4) Bioethanol, and (5) Biodiesel / Oil.
A comprehensive life cycle analysis (LCA) will be performed on this integrated dairy / energy production system. As in any complex system such as this, there are potential tradeoffs in economic performance, environmental quality, and energy inputs. The LCA model will quantify the macro-scale environmental impacts of various configurations of the system.
The outcome environmental impact indicators will include greenhouse gas (GHG) emissions, net energy balances (at the farm and state level), and nutrient use efficiency (and its implications on soil and water quality). The LCA effort for this project will develop life cycle inventories (LCI’s) on the new components of this system and modify and refine existing LCI’s based on the results of the experimental and demonstration work conducted in this project. Optimization techniques will be applied to help understand critical elements of this system and optimal configurations.
Technology Highlights
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Patented polymer-based separations developed by Soil Net, LLC that improve reclamation and re-use of water and enable fractionation of desired products. Customized polymer separations are used at multiple, sequential points across the ARE project and comprises three technologies: (1) Mechanical separation of the large fibers by rotating screens; (2) Separation of the small fibers from liquid by a tapered screw press, leaving the fibers with 65% moisture for bedding, bio-fuels, mulches, or lawn and garden products; and, (3) Separation via aggregating (flocculating) various fibers less than 1 mm and fractions of solids with particles less than 25 microns from liquid fractions in a Diffuse Air Flotation device (DAF), where micronized air is injected into the liquid stream to float the aggregated (flocculated) mass of the 25 microns fraction, the fraction of amino-acids, peptides, and proteins is removed and pass through a press to reduce the moisture content to 65 to 70% (patent applied for). The fibers are subject to physical (maceration) and chemical (reagents) treatment (maceration). The maceration is done in a pin mixer with grooves where the chemicals are forced into the fibers by the rotating pins. This treatment breaks down bonds between lignin, cellulose, and hemi-cellulose, where the hemi-cellulose and lignin is water soluble and separated by washing. The cellulose is hydrolyzed with enzymes to free the carbohydrates (molecules) and make them available for fermentation for ethanol production (apparatus and process for fiber treatment 8444810 B2). Polymers have been proven to be safe for the environment and human consumption and certify in water clarification for drinking water. See Aicardo Roa-Espinosa patents at ARE Results page for patent specifics.
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Process design and equipment for biomass processing developed and manufactured by FEECO International, to include rotary dryer, paddle mixer, grinding mill, and pin mixer. The rotary dryer, developed exclusively for this project, serves the purpose of reducing moisture and rounding off granules creating a stronger pellet. The paddle mixer works with product recycle to agglomerate high moisture fines before entering the dryer. The grinding mill takes oversized product and breaks it down to be used as recycle in the paddle mixer. The pin mixer takes course particles coming off the screw press and breaks them down using chemicals to create ethanol.
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Patented equipment for pre-processing of biomass developed by Soil Net, LLC and Braun Electric Inc. that makes the product more hydroscopic and more readily digestible by cellulases.
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Pipeline for manure processing and fractionation which will be evaluated by University of Wisconsin researchers for the composition of intermediates and products, efficiency of each step, overall energy balance, and the economic tradeoffs of the various products that can be produced.
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Approaches for the evaluation of soluble and pelletized fertilizers produced by the pipeline in laboratory and real farm settings.