(522e) Bio-Oil Production from Algae Grown on Dairy Anaerobic Digestion Effluent: an Independent Senior Design Project

Persistent rises in fossil fuels are rendering bioenergy production on the farm an increasingly attractive alternative. In addition, increasing farm animal densities in the state of Washington are producing a concentrated manure surplus, which exceeds the amount usable on local agricultural lands as fertilizer.

In the context of the NSF MCCE IGERT fellowship (Multinational Collaboration on Challenges to the Environment, Integrative Graduate Education and Research Traineeship) at the University of Washington, our interdisciplinary graduate students team has looked at the integration of Anaerobic Digestion (AD) and biofuel (as Tri-Acyl-Glycerol or TAG) production on dairy farms. In this process, the AD methane is used to produce electrical power, and the resulting carbon dioxide is used to enrich the algae reactor. The nutrient-rich AD effluent is fed to the algae, thus by-passing the need to purchase fertilizer. This concept was incorporated in the UW Chemical Engineering curriculum as an independent senior design project.

Students will look at various process configurations, comparing turbines and SOFC fuel cells as the electricity producing unit, and different downstream processing options for the algal biomass.

The design project will draw knowledge from algae biological data (Holland et. al., in preparation), photobioreactor performances (Professor Al-Dahhan, Washington University Saint-Louis, MI; Vunjak-Novakovic et. al., 2005), SOFC characteristics (Professor Adler, University of Washington), existing AD performances (Van derHaak dairy, WA), flocculation alternatives (Professor Berg, University of Washington). Cost of standard process units will be estimated with the help of engineers from Puget Sound Energy and the King County Wastewater facility in Renton.