Will Washington Provide Its Own Feedstocks for Biofuels?

The study finds that Washington State’s field corn, sugar beet and canola production could satisfy only a small percentage of the State’s annual gasoline or diesel consumption. Linear programming projections for 2008 showed a relatively close match between projected and actual production. Projections for 2009-2011 showed no increase in the State’s capacity to increase biofuel crop feedstocks. In comparison to crop feedstocks, Washington’s total annual lignocellulosic biomass is abundant. However, only a fraction of the biomass could be converted to biofuel due to high costs of collection and processing, competing markets for some biomass, and limitations in current technology.biofuels, biofuel feedstocks, canola, cellulosic inventories, grain corn, linear programming, Washington State

Dairy-CropSyst: Gaseous emissions and nutrient fate modeling tool

Dairy confined animal feeding operations (CAFO) are required to implement nutrient management plans for minimizing the risk of water resource degradation and report gaseous emissions when exceeding certain threshold values. Although tools exist to aid in completing such tasks, few integrate the impact of on-farm manure treatment unit operations such as anaerobic digestion, solids separation, and nutrient recovery. Furthermore, existing tools do not estimate the nutrient value of recovered products and effluent leaving the dairy system or the nutrient fate after effluent is applied to crop fields. Dairy-CropSyst is a decision support tool for researchers and CAFO managers aimed at evaluating the effects of different manure treatment unit operations on gaseous emission and nutrient fate in dairy systems. The model tracks nutrients through the dairy system, including inorganic and organic forms of carbon, nitrogen, and phosphorus. This is accomplished by integrating established transformation and emission equations, performance parameters of manure treatments from industrial data and literature, and using a cropping system model for the land application evaluation. Predicted and observed emission values for greenhouse gases (GHG) and ammonia from different dairy unit operations were found in good agreement. The use of Dairy-CropSyst has the potential to assist the dairy industry in decision making on manure management treatment strategies and as a tool for reporting GHG and ammonia emissions

Economic feasibility of anaerobic digester systems with nutrient recovery technologies

Anaerobic digesters are used worldwide to produce bioenergy and sustainably treat organic waste from municipal, industrial, and agricultural operations. This publication analyzes the economic feasibility of three nutrient recovery technologies that work in tandem with anaerobic digester systems. The Anaerobic Digestion Systems Series provides research based information to improve decision-making for incorporating, augmenting, and maintaining anaerobic digestion systems for manures and food by-products

Anaerobic digester project and system modifications : an economic analysis

This WSU publication provides an abbreviated review of the information found in the longer publication, Renewable Natural Gas and Nutrient Recovery Feasibility for DeRuyter Dairy. It introduces readers to key concerns regarding the profitability of anaerobic digestion systems and includes a discussion of general project costs and potential revenue sources. Additionally, it examines the potential profitability of three alternative anaerobic digester systems: (a) com¬bined heat and power, which is the baseline system; (b) boiler as a substitute for combined heat and power; and (c) renewable natural gas infrastructure

Approaches to nutrient recovery from dairy manure

To support dairy, dairy-allied industry, and agency knowledge and decision-making, this paper provides an overview of the major nutrient recovery (NR) approaches now emerging or in use for recovery or removal of P, N, K, and other salts from dairy manure, particularly after anaerobic digestion (AD). Technologies, markets, and regulatory frameworks are evolving quickly and, as a result, this paper, its technology evaluations, associated performance, and cost estimates must be considered a time-sensitive snapshot of a changing industry

The dairy bio-refinery

Anaerobic digestion is a notable waste management technology that produces renewable energy while improving livestock manure management. The process reduces the release of greenhouse gas emissions (GHGs), volatile organic compounds, pathogens, and odors. Since their inception, some dairy digesters have used “add-on” technologies to improve project economics and address other environmental and management concerns. These add-on technologies convert traditional dairy digesters into dairy manure bio-refineries that integrate the core anaerobic digester with additional downstream equipment to generate value-added products including fuels, power, and chemicals. This publication provides an overview of the bio-refinery concept as applied to a dairy digester, and describes the technologies currently receiving the most interest for use with on-farm dairy digesters. This publication serves as an introduction and overview for the Anaerobic Digestion Systems Series, which provides research-based information to improve decision-making for incorporating, augmenting, and maintaining anaerobic digestion systems for manure and food by-products

The rationale for recovery of phosphorus and nitrogen from dairy manure

This publication explains the rationale for implementing emerging phosphorus and nitrogen recovery technologies on dairies, with a particular focus on the Western United States

Evaluation of Co-Digestion at a Commercial Dairy Anaerobic Digester

Co-digestion of dairy manure with off-farm waste has become a common practice on US farms, however, little data at a commercial-scale is present within the literature. In response, a mesophilic, mixed plug-flow reactor co-digesting 16.36% v/v food processing substrates with dairy manure, was monitored for its performance and substrate effects. Co-digestion, as compared to substrate or manure-only digestion, allowed for more preferred levels of key micronutrients, neutral pH, and additional alkalinity while also producing C/N and C/N/P ratios of 28:1 and 112:4:0.5, respectively. Reduction percentages were 45.36, 55.28, 67.72, and 99.87% for TS, VS, COD, and VFA, respectively, while fecal coliform bacteria as an indicator organism showed a 2 log 10 reduction. A manureonly modeled baseline was developed for comparison with the experimental codigestion data with co-digestion resulting in a 110% increase in biogas production and a tripling of gross receipts with 72% of all receipts being directly due to substrate supplementation. Specific methane productivities for the manure-only and co-digestion scenarios were 0.23 and 0.37 m 3 CH 4 /kg VS load , respectively. Addition of substrates tripled project gross revenues and accounted for 72% of all receipts, however, inclusion of substrates led to significant increases in total nitrogen and phosphorous loading to the farm

Completing a successful feasibility study for an anaerobic digestion project

Today, anaerobic digesters require significant up-front expenditures. As the cost and complexity of anaerobic digesters has grown, so has the demand for analysis of the technical systems and the financial costs and benefits. Though a feasibility study for a large anaerobic digestion project is often completed by an outside consultant, there are many other stakeholders, including farmers, project developers, support professionals, and others, who need to be able to evaluate its quality—whether in selecting a consultant to complete a feasibility study, or in understanding and using the output from a feasibility study. This fact sheet looks at different aspects of feasibility studies—including outlines, guidance, cautions, and recommendations—with an eye toward improving the preparation, evaluation, and use of feasibility studies in the development of successful anaerobic digestion projects. Because there are many existing resources that discuss general feasibility studies, this publication focuses on the areas of feasibility studies that tend to be common for livestock-based anaerobic digestion projects