1. From Refuse to Resource
Recapturing Methane In
Landfill Gas-to-Energy Projects
Anne Regan
Atmospheric Chemistry

2. Atmospheric Methane In the last 650,000 years… In the last 250 years…
400 ppb (Glacial) ↔ 770 ppb (Interglacial)
In the last 250 years…
Human activities have raised methane levels 148% to
1,774 ppb

3. Atmospheric Concentration (2005)
Radiative Efficiencies and Global Warming Potentials of Carbon Dioxide and Methane
Species
Atmospheric Concentration (2005)
Radiative
Forcing
(W m-2)
Lifetime
(years)
20-year
GWP
100-year
CO2
379 ± 0.65 ppm
1.66
variable 1
CH4
1,774 ± 1.8 ppb
0.48 12 72 25
Source: Forster, P., et al. Changes in Atmospheric Constituents and in Radiative Forcing; Fourth Assessment Report of the IPCC. Cambridge University Press: Cambridge, UK, 2007.

4. Global Sources of Methane
Methanogenic bacteria in wet, oxygen-deficient environments release ~ 80%
2{CH2O} + 2H2O  2CO2 + 8H+ + 8e-
CO2 + 8H+ + 8e-  CH4 + 2H2O
NET: 2{CH2O}  CO2 + CH4
Natural gas leakages, coal mining, and other fossil fuel sources release ~ 20%

5. Global Sources of Methane
Source: Wuebbles, D.; Hayhoe, K. Atmospheric methane and global change. Earth-Science Reviews. [Online] 2002, 57,

6. Atmospheric Methane (2005)
Source:

7. Methane Sinks ~ 5% taken up by methanotrophs
~ 5% uplifted to stratosphere
~ 90% removed by tropospheric ·OH

8. Tropospheric Methane Chemistry
•OH
H2O
•CH3 O2
CH3O2•
CH3O• O2 NO
NO2
HO2•
VOC-sensitive
(High NOx)
CH2O
PANs hv hv O3 H2 H•
CHO• CO
Source: Wuebbles, D.; Hayhoe, K. Atmospheric methane and global change. Earth-Science Reviews. [Online] 2002, 57,

9. Tropospheric Methane Chemistry
•OH
H2O
•CH3 O2
CH3O2•
CH3OOH
CH2OOH hv
•OH
Nox-sensitive
(Low NOx)
HO2• O2
•OH
H2O
CH2O hv hv H2 H• CO
CHO•
Source: Wuebbles, D.; Hayhoe, K. Atmospheric methane and global change. Earth-Science Reviews. [Online] 2002, 57,

10. Tropospheric Methane Chemistry
Methane oxidation cycle
Accounts for much of the CH2O in the troposphere
Produces ~ ¼ of the total CO
CO + •OH  H• + CO2
Forms O3 (high NOx)
Positive feedback ( ↑ CH4… ↑ CO… ↓ •OH )
↑ methane, ↑ atmospheric lifetime, ↑ methane…

11. Stratospheric Methane Chemistry
Major source of stratospheric water vapor
CH4 + •OH  •CH3 + H2O
May enhance polar stratospheric cloud formation and exacerbate ozone depletion
Reservoir for Cl•
CH4 + Cl•  •CH3 + HCl
Prolongs ozone depletion

12. U.S. Anthropogenic Methane Emissions (2006)
Source: Inventory of U.S. Greenhouse Gas Emissions and Sinks: Office of Atmospheric Programs; U.S. Environmental Protection Agency, Government Printing Office: Washington, DC, 2008.

13. U.S. Solid Waste by Category (Before Recycling, 2006)
Source: Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for U.S. Environmental Protection Agency. Retrieved from

14. Management of U.S. Solid Waste (2006)
Source: Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for U.S. Environmental Protection Agency. Retrieved from

15. Municipal Solid Waste Landfills
Residential
Commercial
Non-hazardous industrial

16. Trends in U.S. Municipal Solid Waste Generation (1960 – 2006)
Source: Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for U.S. Environmental Protection Agency. Retrieved from

17. Municipal Solid Waste Landfill Emissions
~50% methane
~45% CO2
Less than 5% N2
Trace amounts of non-methane organic compounds
various HAPs, ozone depleting substances, and VOCs
 Landfill gas contributes to the greenhouse effect, smog formation, health and explosion hazards

18. CH4 + 2O2  CO2 + 2H2O + heat energy
Landfill Gas Controls
Combustion
Flaring
Energy recovery (IC engines, gas/steam turbines)
Purification  Natural gas
CH4 + 2O2  CO2 + 2H2O + heat energy

19. U.S. Greenhouse Gas Emissions Allocated to Economic Sectors (1990 – 2006)
Source: Inventory of U.S. Greenhouse Gas Emissions and Sinks: Office of Atmospheric Programs; U.S. Environmental Protection Agency, Government Printing Office: Washington, DC, 2008.

20. Trends in U.S. MSW Landfill Emissions (1990 – 2006)
Source: Inventory of U.S. Greenhouse Gas Emissions and Sinks: Office of Atmospheric Programs; U.S. Environmental Protection Agency, Government Printing Office: Washington, DC, 2008.

21. Landfill Methane Outreach Program
Created by the EPA in 1994
Goal: lower the barriers to building landfill gas energy recovery systems
435 landfill-gas-to-energy facilities already generating 1,325MW of electricity
~550 candidate landfills identified
Collective potential to power more than 1.6 million homes annually

22. Chautauqua County Landfill
83 acres in the town of Ellery, NY
Serves: Chautauqua County, parts of Erie and Cattaraugus Counties, and Pennsylvania
~ 300,000 tons of solid waste per year
Household
Commercial
Nonhazardous industrial
Construction/demolition waste
Sewage treatment sludge

23. Chautauqua County Landfill

24. Or you could just go to jail…

25. LFG Collection System

26. The Working Field

27. Flare

28. Proposed Landfill Gas-to-Energy Project
Power plant to house four 1.6 MW IC engines
Grid connection
$9 to $10 million cost
$40 to $80 million profit
Expected to be operational by end of 2009
Will create 2 full-time and 3 part-time jobs
Will generate enough electricity to power over 4,000 homes a year

29. Considerations… Combustion emissions regardless of energy recovery
NOx, CO, PM, NMOCs, halogenated compounds
Internal combustion engines
Least expensive
Most efficient at generating electricity
Release largest amounts of NO2 and PM
CO emissions second only to flaring
Least efficient at controlling halogenated compounds

30. Considerations…
Landfills must be currently operating/recently closed with ≤ 1,000,000 tons of waste-in-place
Economically viable for only 30 years after closing
Projects can only operate at their max. capacities
Dependent on wastefulness

31. Conclusion Landfill Methane Outreach Program
↓ methane by 28 million MTCE = removing 19 million passenger cars from the road for 1 year
Accomplished using existing technologies
Sewage treatment plants, livestock waste-to-energy
Refuse  Resource

32. Sources
Forster, P., et al. Changes in Atmospheric Constituents and in Radiative Forcing; Fourth Assessment Report of the IPCC. Cambridge University Press: Cambridge, UK, 2007.
Inventory of U.S. Greenhouse Gas Emissions and Sinks: Office of Atmospheric Programs; U.S. Environmental Protection Agency, Government Printing Office: Washington, DC, 2008.
Manahan, S. E. Environmental Chemistry, 8th Ed.; CRC Press: Boca Raton, FL, 2005.
Methane as a Greenhouse Gas. U.S. Climate Change Science Program Office. methane18jan2006.pdf (accessed April 9, 2008).
Methane: Sources and Emissions. U.S. Environmental Protection Agency. (accessed April 12, 2008),
Wuebbles, D.; Hayhoe, K. Atmospheric methane and global change. Earth-Science Reviews. [Online] 2002, 57,
Turning a Liability into an Asset: A Landfill Gas-to-Energy Project Development Handbook. Landfill Methane Outreach Program; U.S. Environmental Protection Agency, Government Printing Office: Washington, DC, 1996.
Municipal Solid Waste Generation, Recycling, and Disposal in the United States: Facts and Figures for U.S. Environmental Protection Agency. (accessed April 12, 2008).
Landfill Methane Outreach Program (LMOP). U.S. Environmental Protection Agency. (accessed April 14, 2008), 2008.
Jaramillo, P.; Matthews, H. S. Landfill-Gas-to-Energy Projects: Analysis of Net Private and Social Benefits. Environ. Sci. Technol. [Online] 2005, 39,
Panteli, P. K. Deputy Director of Public Facilities, Chautauqua County Landfill: Ellery, NY. Interviewed April 11, 2008.
Emission Factors: Municipal Solid Waste Landfills. Technology Transfer Network, Clearinghouse for Inventories and Emission Factors; U.S. Environmental Protection Agency, Government Printing Office: Washington, DC, 1998.
Good, D. A.; Francisco, J. S. Atmospheric Chemistry of Alternative Fuels and Alternative Chlorofluorocarbons. Chem. Rev. [Online] 2003, 103,
Panteli, P. K. Engineering Report: Landfill Gas Recovery Facility. Chautauqua County Department of Public Facilities, Division of Solid Waste, 2008.
Grant to fund conversion of methane into energy. The Buffalo News, December 29, 2007.
Municipal Solid Waste. U.S. Environmental Protection Agency. (accessed April 14, 2008), 2008.