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Anaerobic Digester Feasibility on University of Michigan Campus Logan Vear 1 , Elena Essa 2 , Adam Simon 3 , Susan Fancy 4 University of Michigan Dept. of Civil and Environmental Engineering 1 , University of Michigan Dept. of Statistics 2 , University of Michigan Dept. of Earth and Environmental Sciences 3 , University of Michigan Energy Institute 4 Background and Motivation Sustainability Goals Addressed Other U-M Waste Reduction Efforts • A biodigester for U-M with fiscal year FY 2017 maximized organic waste tonnage at 5,059 tons would: • reach a 33% waste reduction for the university (Figure 6) • produce 1,100 MWh of electricity contributing to 0.2% of total U-M electricity use • Implementing a U-M biodigester would further U-M’s progress towards the waste reduction goal and the emissions reduction goal and while also generating energy Figure 4: U-M composted waste tonnage FY 2014-2017 • Environmental degradation is exacerbated by human activity that produces greenhouse gases and solid waste 1,2 • Landfills present the third largest source of methane emissions in the nation 2 • U-M created 2025 campus sustainability goals 3 in 2011 to address these environmental concerns (Figure 1): • Reduce waste tonnage by 40% below 2006 levels • Decrease greenhouse gas emissions by 25% below 2006 levels Figure 5: U-M maximized compost waste tonnage FY 2014-2017 Figure 7: U-M landfilled waste tonnage after composting FY 2014-2017 Figure 1: Planet Blue campus sustainability goal topics ● Present progress: • 3% waste reduction based on fiscal year (FY) 2017 • 5% decrease in greenhouse gas emissions • This research investigates how an anaerobic digester (biodgester) could decrease landfill waste and greenhouse gas emissions and increase renewable energy generation for U-M Anaerobic Digestion • Biodigesters convert organic waste into majority methane biogas • Organic materials decomposed in oxygen-free environment by natural microbes • Capture and store biogas and separate residual nutrient-rich solids and liquids 4 • The biogas can be utilized as power and heat (Figure 2) Figure 2: Biodigester organic waste to energy process Potential BIOFerm Digester • Worked with University of Wisconsin Oshkosh on their anaerobic digester • Can manufacture small-scale EUCOlino digester prefabricated system 5 (Figure 3) or customized system • Processes 1,000-6,500 tons organic waste per year • Allows for variety of feedstock • Includes a combined heat and power system Figure 3: EUCOlino compact, plug and play anaerobic digester Locations and Applications on Campus • The biodigester at U-M could be situated at Matthaei Botanical Gardens or MCity Test Facility (Figures 7 & 8) • High research potential use with EV charging and powering MCity or Matthaei facilities Figure 7: MCity Test Facility Figure 8: Matthaei Botanical Gardens Partnership with Ann Arbor • 799 tons organic waste was diverted from landfills in FY 2017 through U-M Student Life Activities • 185 tons from Zero Waste Events • Zero Waste initiative for events at Michigan Stadium • For 6 home football games in 2017, 88.17% of waste diverted from landfill (Figure 9) 7 • These programs could contribute to the feedstock of a biodigester, further decreasing waste and increasing renewable energy production Figure 9: Waste collection from 2017 Michigan Stadium football games Other Universities • MSU anaerobic digester processes 22,000 tons organic waste/year, producing 2,800 MWh/year for campus buildings 8 (Figure 10) • University of Wisconsin Oshkosh employs 3 digesters 9 • Urban dry system converts 10,000 tons of waste/year to 3,300MWh/year of electricity supplying 8% of the university’s electrical needs • Research-based EUCOlino dairy system to continuously produce 64kW of combined power and heat • UC Davis digester converts 20,000 tons waste/year to 5,800MWh/year 10 Conclusions • Implementing an anaerobic digester at U-M presents an avenue to: • significantly contribute to the 2025 sustainability goal of 40% reduction in waste tonnage by reducing waste 33% • contribute to reaching the 2025 goal of 25% emission reduction • The biodigester could potentially be housed at Matthaei Botanical Gardens or MCity providing significant research potential for a closed loop renewable energy system • A biodigester could be jointly owned and operated with the city of Ann Arbor to divert a larger amount of waste generated from U-M and the city from the landfill • A biodigester offers an effective approach for universities to increase sustainability and minimize negative environmental effects Figure 10: MSU anaerobic digester Acknowledgements We thank the University of Michigan Earth and Environmental Science Department, the University of Michigan Energy Institute, Adam Simon, Susan Fancy, Lydia Whitbeck, Anya Dale, Tracy Artley, Keith Soster, and Bob Grese, Greg McGuire, Matt Naud, and Jeremy Moghtader for providing support and feedback on this research. References 1. “Sources of Greenhouse Gas Emissions.” EPA, Environmental Protection Agency,14 Apr. 2017. 2. “Basic Information about Landfill Gas.” EPA, Environmental Protection Agency, 14 Mar. 2018. 3. “Campus Sustainability Goals.” Planet Blue, 5 Mar. 2018. 4. Khalid, Azeem, et al. “The Anaerobic Digestion of Solid Organic Waste.” Waste Management, 2011. 5. “Compact, Small-Scale Digester, BIOFerm Energy Systems.” BIOFerm™ Energy Systems. 6. “Ann Arbor Biodigester Feasibility Study.” Fishbeck, Thompson, Carr & Huber, Inc., June 2017. 7. “Michigan Diverts 88.17 Percent of Its Waste in 2017 - University of Michigan.” University of Michigan Athletics. 8. “South Campus Anaerobic Digester.” Anaerobic Digestion Research and Education Center (ADREC). 9. “UW Oshkosh Biogas Systems.” Biogas Systems. 10. “UC Davis Biodigester Turns Campus Waste into Campus Energy.” UC Davis College of Engineering. • The city of Ann Arbor holds the potential to utilize its waste-water treatment, sludge, and other organic waste around the city as feedstock for a biodigester • In 2017, a feasibility study for an anaerobic digester was generated for the city of Ann Arbor to determine the economic benefits and the feedstock composition for the city of Ann Arbor 6 ● Benefits of a biodigester include a reduction of landfill waste, and increase in generation of renewable energy • Both Ann Arbor and U-M have previously shown interest in partnership, making a biodigester more feasible • Combined organic waste from U-M and the city of Ann Arbor annually would be approximately 110,000 tons per year, which equates to roughly 23,000 MWh per year of renewable electricity generation Figure 6: U-M landfilled waste tonnage FY 2014-2017
