1. Renewable Biogas Options
Dave Parry, CDM

2. Overview of Biogas Options
Introduction
Technologies
Biogas Treatment
Key Issues
Case Studies
Summary
Introduction (Biogas use drivers, value of energy forms, etc.)
Key issues influencing biogas use decisions (economics, air quality, technology)
Technologies (Cogeneration: IC engines, gas turbines, fuel cells; Vehicle fuel: CO2 removal, compression)
Case Studies (EWA, KC West Point, Lethbridge, Pierce County)
Summary

3. Biogas Utilization Drivers
Rising Energy Costs (Electricity, Natural Gas, and Gasoline)
Communities Desire to be Green
Initiatives to Reduce Green House Gases
Increasing Biogas Production (Growth, Codigestion)

4. Value of Biogas Electric generation assumes 35% elec eff and $0.1/kWh
Cogen assumes same elec parameters and 45% heat recovery
Natural gas assumed at $1 per therm
Biogas boiler at 75% and NG boiler at 80%
Vehicle fuel at 2.7$/gal unleaded

5. Biogas Value Increases With Flow

6. Biogas Use: Part of an Integrated Energy System
Import
Utility
Electricity
Plant Demand
Export
Generated Electricity
Natural
Gas
Vehicle Fuel
Plant Heat Demand
Recovered Heat
Organic
Waste
Digester Gas
Fuel
Gas
Heat
Effluent Heat Rejection
Supplemental Heat
Digesters
Waste Gas Flares
Boilers

7. Options for Biogas Use

8. Options for Biogas Use Comparison: Capital Cost Maintenance Cost
Emissions (NOx, CO)
Variable Gas Quality
Gas Quality, Pressure
Noise

9. Biogas can be Utilized in Natural Gas Vehicles

10. Biogas Treatment Needed for Various Options
H2S Reduction
Pressure Boosting
Siloxane Reduction
Particulate Reduction
Moisture Reduction
From
Digester To
Beneficial Use
CO2 removal and compression required for vehicle fuel
Iron Sponge
Blower
Particulate Filter
Heat Exchange and Separator
Activated Carbon

11. Biogas Management: Blending, Holding, and Storage

12. Gas Treatment Equipment

13. Cost of Generation is Dependent on Natural Gas Rate and Heat Recovery
0.160
0.140
Natural Gas w/ Heat
0.120
Natural Gas (NG)
0.100
$/kWhe
0.080
NG w/ Heat
Recovery
Natural gas with beneficial use of heat or biogas with supplemental natural gas for boiler
0.060
Biogas
0.040
0.020
0.000
0.4
0.5
0.6
0.7
0.8
0.9
$/therm

14. Payback as a Function of Electricity Costs
Costs are typically $3k to $4k/kW
Payback time is shorter with lower capital costs and higher electricity rate

15. Case Studies of Successful Biogas Utilization Projects

16. Encina Water Pollution Control Facility, Carlsbad, CA
Natural Gas
Digester Gas
Aeration and Agitation, Dryer
750 kW
750 kW
750 kW
750 kW

17. The City of Lethbridge Lethbridge Wastewater Treatment Plant
Digestion as energy source
Lethbridge Wastewater Treatment Plant
Lethbridge, Alberta, Canada

18. King County, WA South Treatment Plant

19. Basics for Success
Early Buy-in from Stakeholders (Economic, Environmental, Operations, and Social)
Life Cycle Cost Effective (Accurate Cost Estimates)
Understanding of Regulations and Permits
Integrated and Flexible Design (Power, Fuel, Heat) that is adaptable to varying conditions and energy rates
Proper Attention to Gas Treatment and Management

20. Questions?

22. First Level Slide Major Points More Major Points
What You Will Discuss Today
More on What You Will Discuss
Etc.

23. Other Samples
Point 1
Details
Etc. with graph to right

24. Final Slide Major Points More Major Points What You Did Discuss Today
Questions?