Algae for Fuels Pilot Project

PROJECT OVERVIEW
Biomass-based energy holds important potential as a viable renewable alternative to non-renewable fossil-based energy supplies; however significant challenges to biomass energy technologies remain to be overcome before such a role can be achieved at a large scale. Researchers at the University of Minnesota's Center for Biorefining, in partnership with the Metropolitan Council, are using this appropriation to develop, build, and test a pilot scale fuel production system that uses the nutrients in sewage wastewater to grow algae that can then be harvested to produce biodiesel. Additional benefits resulting from the system may include improved water quality, minimized freshwater and land use, reduced carbon emissions, and capture and recycling of plant nutrients. With additional research and development of this system it could potentially be implemented at other wastewater treatment facilities and adapted to other waste streams throughout Minnesota and beyond.
OVERALL PROJECT OUTCOME AND RESULTS
Current biomass energy technologies have encountered economic, ecological, and policy concerns, including feed stock procurement, energy balance, carbon footprint, competition for food and fuel, water use, and others. This project was built on our existing collaborative R&D partnership to demonstrate an innovative photosynthetic algae production system which simultaneously produces high lipid oil for bio-fuel production, captures and recycles nitrogen and phosphorus from wastewater, and sequesters carbon dioxide. The goal of the project was to develop, build, and test a pilot scale algae production system that will treat concentrated wastewater and animal facility wastewater and generate algal biomass for production of biofuels and bioproducts. More than 10 high performance algae strains have been developed for specific applications such as oil accumulation, nutrient removal, growth under low temperature and low light conditions, and accumulation of high value lipids. Growth conditions were optimized for specific applications. A pilot cultivation facility with a cultivation volume of 20,000 liters was developed and demonstrated. The microwave assisted pyrolysis was found to be an excellent conversion alternative to conventional oil extraction based biodiesel process, and the hydrothermal process is a cost effective pretreatment technology to improve dewatering of algal biomass. The life cycle analysis results indicate that our technologies, which integrate wastewater into algal cultivation, can improve the environmental performance of algal biofuels. The life cycle analysis study also suggests that utilization of multiple major waste streams in wastewater plants should be developed to maximize the economic and environmental benefits of algae based technologies. The outcomes of the project point to a great potential of algae technologies for simultaneous removal of nitrogen, phosphorus, chemical oxygen demand (COD), and other nutrients in municipal and animal wastewaters; sequestration of carbons in organic matters and flue gas; and at the same time accumulation of biomass for production of high vale biofuels and bioproducts.

PROJECT RESULTS USE AND DISSEMINATION
Information about the project results were disseminated through more than 10 presentations at national and international conferences, five demonstrations to stakeholders, eleven peer-reviewed journal publications, and through a website: http://biorefining.cfans.umn.edu.