Anaerobic Digestion: Turning One Man’s Trash Into Another Man’s Treasure

1. Anaerobic Digestion: Turning One Man’s Trash Into Another Man’s Treasure January 20, 2009 Dr. Catherine Keske Dr. Sybil Sharvelle

2. Recovering Manure to Produce Energy • Benefits of Anaerobic Digesters • How Digesters Work • Trends and Feasibility • Economic Issues • How to Get Involved or Learn More • Questions

3. Benefits of Anaerobic Digesters Environmental Economic and Social On-farm energy generation (avoid electricity purchases) May sell energy to utilities Savings on bedding Sale of composted solids Carbon credits available Renewable energy certificates Odor control • Production • Soil management • Manure management • Biogas production • Reduces environmental pollution • Water • Green house gases • Ammonia

4. Anaerobic Digestion: How It Works Green Power Anaerobic Environment Cogeneration CH4 Acids  CH4 Organics  Acids Hot Water High BOD Waste High Nutrient Low Odor Waste

5. Model Project: Quadra Project in Indiana Green Power Frito Lay Biodiesel Plant Cold Soybean Oil WE Can Do This in Colorado Too! Food Waste Anaerobic Digester Hog Waste Hot Soybean Oil ADM Soybean Processing

6. Waste Suitablility • Low solids content, < 14% solids • Low inorganic content • Soil • Rocks • Higher organic content, more energy content

7. Average Annual Minimum Temperature Colorado – Cold Climate

8. Covered Lagoon – Not an Option

9. Colorado – Dry Climate Need to Find Nearby Source of Wastewater or Add Groundwater to Waste Average Annual Precipitation In Colorado

10. Successful Digester at Dairy in Montana

11. Alternative Design - Two Stage Leachate Collection Low Moisture Manure and Other Waste Organics Anaerobic Digester High Organic Leachate Methane Gas

12. Costs of Anaerobic Digesters • Cost of the digester: Approximately $1 million Average life: 15 yrs. (Range: 10-20) • Cost of the solids separator: Approximately $75,000 **Key to raising profitability** • Opportunity cost Cost of your next best alternative

13. Are Digesters Profitable? “Yes…” • Several models show profitability • Measured in cash flows associated with the investment • Critical to use a solids separator • Use the solids as a co-product • Bedding is the most economic use • Larger herds lead to economies of scale • Key element to profitability: Energy prices

14. “…But…Will a Digester Work for My Operation?” • Greater than 500 head (more than 1,000 head preferred) • Requires steady flow of manure (CAFOs) • Climate matters – the warmer the better • Must be able to use the biogas • “Community” digesters are an option • Pipelines transport waste to central site • Could consider other facilities (e.g. food processing)

15. “Yes, But…”Economic Considerations • Majority of studies conducted in the East • Profitability relies on carbon credits • $2 per metric ton of CO2 • “Net positive gain” may include a net gain to the environment (not necessarily a net gain to the farmer/rancher) • Profitability critically depends upon energy prices

16. Want to Learn More? • Contact Us! • Institute for Livestock and the Environment: http://ile.colostate.edu • USDA Producer Workshop 2/19/09 York, Nebraska • AgStar: http://www.epa.gov/agstar/ • Colorado Governor’s Energy Office: http://www.colorado.gov/energy/index.asp Sponsoring feasibility studies

17. Questions?