1. Biogas
Jeff Hoover

2. Potential Gas Supply
Biogas is derived from anaerobic (in lack of oxygen) digestion of biomaterial.
Primarily used in engine-generators and heat generation
May be upgraded to biomethane, equivalent form to Natural Gas.

3. Source Dairies Cow manure California
3.6 million bone dry tons (BDT) (zero-moisture content) of manure

4. Harvesting Source Flushed freestall Scraped freestall
Hosed and piped off
Scraped freestall
Dry lot w/ flushed freestall
Scraped dry lot (85-90%)

5. Other sources Slaughterhouse waste material Hog, turkey/poultry manure
Crop Residues
Food Processing Wastes
Landfill food, green, composite organic waste.

6. Digestion plants Ambient-temperature Covered Lagoon Complete mix
Not temperature controlled, thin waste
Low tech, cheapest
40 day retention time
Complete mix
Heated, thicker waste
15+ day retention time
Plug Flow
Thicker waste

7. Digestion types Thermophilic Mesophilic
Optimal for quickest production °F
Mesophilic
95-105°F

8. Conclusion, Output “Technical Potential” of Methane production
23 billion cubic feet per year
220MWe
Total statewide demand of NG = 2,200 billion cubic feet per year
23 billion cft/yr equates to ~1% of NG demand

9. Questions?
Does this biogas appear to be a useful way of producing heat/electricity/vehicle transportation?
Why or why not?
What drawbacks can be seen from these observations?