From dairy farm to bio-refinery: developing technologies to produce environmentally friendly fuels, power, and value added products

The Center for Sustaining Agriculture and Natural Resources (CSANR) at Washington State University (WSU) is pursuing a combination of fundamental research, industrial collaboration, and extension to develop a suite of technologies that can be deployed to convert current dairy farms to modular, extendable and environmentally friendly bio-refineries. The central process anchoring the bio-refinery concept is anaerobic digestion (AD), with recent efforts to explore how pyrolysis can complement AD. Using the anaerobic digester to treat a combined stream of off-dairy organics and manure, can reduce the cost of waste treatment and enhance production of biogas for utilization as fuel or in a combined heat and power (CHP) system. The chemical conversion of nitrogen in the digester and subsequent fiber separation allows the effluent to be further processed using a variety of nutrient recovery technologies. Capturing nitrogen and phosphorus from the digester effluent reduces the potential for over application of these nutrients during later field application and can provide additional revenues. Additional downstream water treatment technologies can upgrade a portion of the effluent for use as animal drinking water. After digestion, the resulting fiber has traditionally been composted or more recently used as animal bedding. While animal bedding continues to be a high value use for this material, excess fiber can be combined with off-dairy woody biomass in a pyrolysis reactor to produce heat and biochar. The goal of this presentation will be to walk the audience through the bio-refinery concept and highlight the integration with future technologies including the production of biochar.