1. UC Davis Biogas Energy Project Ruihong Zhang, Professor Biological and Agricultural Engineering University of California, Davis Email: rhzhang@ucdavis.edurhzhang@ucdavis.edu AWWEE Workshop: Major Drivers to Transformation in California Energy and Water Markets May 22, 2012, Sacramento

2. Presentation Outline Status of anaerobic digestion technologies and opportunities for further development UC Davis Biogas Energy Project for new technology development, demonstration and commercialization

3. Value Positioning of Biogas Energy Systems Biogas Sugars, Amino acids, Fatty acids CH 4, CO 2 Anaerobic Digester H 2, CO 2 Organic acids Biogas Energy  Electricity and heat  Natural gas  Compressed natural gas  Liquefied natural gas  Gasoline  Chemicals Digester Effluent  Nutrients  Fibers  Water Organic Waste  Food  Collected Green  Agricultural $$$ $$$ Carbon Credit

4. Wastewater Digestion Technologies Current status – Well established for treatment of sewage, animal manure (swine and dairy), and some food processing wastewater – Common technologies: covered lagoon, completed mixed digester, plug flow digester, upflow sludge blanket reactor (UASB) Opportunities for new technology development – Creative digester design and integration of unit operations to provide higher energy efficiencies and more capabilities to handle variable influent – Co-digestion of different wastes (e.g. food waste with sewage or manure)

5. Solid Waste Digestion Technologies Current status – Europe has several technologies in commercial use for more established markets. – US has the first commercial technologies for emerging markets Opportunities – Digester technology implementation and integration of digestion with waste preprocessing and composting operations – US project and business models

6. Organic Resource Recovery with Advanced Anaerobic Digestion 6 Solid Organic Residuals: Food Processing and Agricultural Residues, Animal Manures, Municipal Solid Waste,

7. A Real Problem with Solid Waste Millions of tons of organic waste dumped in landfills every year result in harmful greenhouse gas (GHG) emissions Mandates require businesses producing high volumes of organic waste to seek more sustainable waste disposal solutions Businesses have committed to sustainability and are now scrambling to follow through – Wal-Mart: Zero waste by 2014; all suppliers must report waste and greenhouse gases http://walmartstores.com/sustainability/9292.aspx – Campbell: new sustainability policy http://www.campbellsoupcompany.com/csr/planet.asp Anaerobic digestion (AD) of organic solid waste has not been successfully implemented in the US to date in commercial scale

8. Food Scraps in the US (EPA) Amount of food scraps – 44 million tons per year – 25% food prepared Cost of disposal – $1 billion per year – $20 per ton Current method of management – 97% disposed in landfill – 3% recovered for composting or combustion

9. Needs For Efficient Solid Waste Digester Technologies Capable of handling multiple and variable biomass feedstock from different supply sources Can be easily scaled up and down Easy to operate and maintain (automation) High conversion efficiencies and smaller foot prints Affordable cost

10. Biogas Energy Project at UC Davis Research and demonstration of new anaerobic digestion and biogas energy technologies for converting various organic residuals into biogas energy and biobased products Public education on waste to energy conversion and environmental management

11. UC Davis Biogas Project Sponsors

12. UC Davis Technology Anaerobic Phased Solids (APS) Digester Two-stage digestion system that has first stage sequential batch loaded digester and continuous second stage digesters Allows for high system stability regardless of fluctuations in loading and waste composition Provides even gas production and rapid waste digestion Mesophilic and thermophilic temperature options Can be configured for sustained hydrogen and methane production Well suited for treating high-solids (10 - 50% total solids) lignocellulosic waste streams, such as: – Municipal solid wastes – Green and food wastes – Agricultural residues

13. Hydrolysis Reactors Converting Solids into Organic Acids and Producing Hydrogen Gas Day 10-12 Biogasification Reactor Digesting Organic Acids and Producing Methane Gas Separated Water Returned to Tank; Excess Discharged for Treatment & Recycling Separated Solids Post treatment for Soil Amendment Residual Material & Water Drained & Separated APS Digester Technology 13 Biogas

14. Three stage anaerobic digestion Well suited for treating highly degradable solids waste streams and mixed solid/liquid waste streams, such as: – Municipal food waste – Food processing waste – Biosolids – Meat product waste slide 14 UC Davis Technology High Rate Digester (HRD)

15. HRD: High Rate Digester Liquid Feed Solids Feed Grinder Hydrolysis Reactor (HR) Wet Grind Biogasification Reactor (BGR) Solids Separator Water Recycle Biostabilization Reactor (BSR) Biogas Out Liquid Effluent CONTROLS AND DATA ACQUISITION PROPRIETARY MIXING, CONTROL & MEDIA PRESSURE, TEMPERATURE, MASS FLOW, pH, LEVEL, OTHER INPUTS INPUTSOUTPUTS VALVES, PUMP BOILER MIX, PUMP OVER, TRANSFER PERF., PERFORMANCE & DATA TREND

16. APS Digester Demonstration System 16 UC Davis Biogas Project Digester capacity – 3-5 tons per day, Digestion temperature – 125-135 F, Digester volume – 50,000 gal Expected biogas yield –350-583 m 3 /day, Electricity output – 600- 1200 kWh/day

19. Food Processing Residuals from Campbell Soup Plant in Sacramento Food Waste (Average): Moisture – 80% Total Solids – 20% Volatile Solids – 19%

20. APS-Digester Performance Digester testing with 200 tons of food processing residuals from June 2008 to April, 2009 Digester Performance Summary: – Solids reduction in food waste: 89.5% for total solids, 90% for volatile solids – Biogas production: average 4,600 ft 3 /ton (wet) – Methane production: average 2760 ft 3 /ton (wet) (7 ft 3 /lb VS) – Energy content in biogas: 27 therm/ton (wet) – Biogas composition: 55-60% methane, 2-5% hydrogen – Digester pH: 5-7 for hydrolysis reactor and 7-8 for biogasification reactor.

21. Clean World Partners Commercial Projects American River Packaging – 8-10 ton per day mixed organics (papers and food waste) City of Sacramento – 25 ton per day organic waste with a potential to expand to 300 ton per day capacity UC Davis Renewal Energy Anaerobic Digestion Project - 22-35 ton per day mixed campus waste (animal manure, food scraps, papers, yard waste, etc.)

23. Clean World Partners Built the First Commercial Digesters for Food and Paper Waste at American River Packaging, Sacramento www.cleanworldpartners.com

24. Clean World Partners Projects American River Packaging (ARP): Packaging manufacturer with corrugated waste 8 tons per day (0.5 cardboard and 7.5 tons food waste) System size 10 tpd (accounting for paper absorption) Producing 1300 kWh per day of electricity with micro-turbines for use on site Food waste coming from local food processors System continuously operating since March 16, 2012 slide 24

25. 25 ARP Organic Waste Recycling Center

26. Clean World Partners Current Projects UC Davis: Moving towards zero waste and showcasing conversion of closed landfill into valuable resource Phase I - 25 tons per day manures from campus and food waste from campus dining facilities Phase II – 35 to 50 tpd separated organics from MSW Allow other surrounding communities to use digester system Combining landfill collection and digester gas streams Producing electricity to feed its net zero community Sophisticated preprocessing system Opening December 2012 slide 26

28. UC Davis CWP Project slide 28

29. Successful Technology Development and Commercialization Research innovation and technology development Public and private investment and partnership Competent and effective technical, management, and business development Favorable market environment