1. State of Methane Emission and Oxidation Research
Stephanie C. Bolyard, PhD
Research and Scholarships Program Manager

2. Landfill Methane Production
CO2
CH4 Recovery
CH4 Emitted
CH4 oxidation
Gas well
CH4 Production
CH4 Recovery + CH4 oxidation + CH4 Emitted

3. Methane Emissions and Oxidation
Understanding methane emissions and oxidation if challenging due to operational limitations, monitoring challenges, weather, and site specific conditions.
Quantifying emissions is important to meet regulatory requirements.

4. Landfill Gas Research Focus
Emissions quantification
Accurate/easy field measurement methods
Methane oxidation
Accurate data under varying field conditions
Collection efficiency
Data gaps
Accurate measurement

5. Measuring Fugitive Emissions
GRANTEE: SCS Engineers
(in partnership with Waste Management and Veolia NA)

6. Vertical Radial Plume Mapping
Measurement of
Methane Emissions
Vertical Radial Plume Mapping
Tunable diode laser/FTIR/Cavity Ringdown Spectroscopy (newer, emerging methods)
Differential Absorption LiDAR
VRPM method, tracer gas method, differential absorption LiDAR method, micrometeorological method, flux chamber method

7. Measurement of Methane Emissions Tracer Methods
Micrometeorological Eddy-Covariance method
Flux Chamber
VRPM method, tracer gas method, differential absorption LiDAR method, micrometeorological method, flux chamber method
Vertical radio plum mapping: collect path-integrated concentration (PIC) data from multiple beam paths in a plane and combine these with optimization algorithms to map the field of concentration across the plume of contaminant (Hashmonay et al. 1999; Hashmonay et al. 2001). This test method currently describes three method
Tracer correlation plume measurements: use of acetlyene
Eddy-covariance: measure and calculate vertical turbulent fluxes within atmospheric boundary layers.
Lidar: (light detection and ranging—the optical equivalent of radar) The basic Lidar technique [10] a pulse of laser radiation, transmitted into atmosphere, and measures the light scattered by the
example results from methane DIAL measurements at landfill sites, and the conclusions are given in
uses a pulse of laser radiation, transmitted into atmosphere, and measures the light scattered by the
atmosphere and returned to the system. DIAL is an extension of this using (at least) two laser pulses atmatodspifhferenatnwdarveetluernngetdhst.o the system.

8. Landfill Fugitive Emissions Study
Tracer gas and DiAL methods appear to be the most promising approaches for landfill fugitive methane measurement
Study has re-defined EPAs perspective on measuring fugitive emissions
Help industry improve gas collection efficiency, reduce emissions, refine carbon footprint estimates
tracer gas and DiAL methods appear to be the most promising approaches for landfill fugitive methane measurement. Considering the quantification objectives, a global assessment can be easily derived with tracer gas whereas a more comprehensive study of localized site specific performances can be undertaken with DiAL.

9. Porosity Effects on CH4 Oxidation
GRANTEE: Florida State University (Jeff Chanton)

10. Porosity effects on CH4 oxidation (FSU)
At the time of this research the guidelines assume landfill cover soils oxidize 10% of CH4 transported through cover
Hesitant to embrace recent work showing higher oxidation
Too limited to be representative of most landfills
Oxidation highly dependent on flow
Objectives of this study:
Evaluate CH4 oxidation across multiple sites
Effect of gas flow
90 %
10 %
100 %

11. Porosity Effects on CH4 Oxidation Theoretical Max. Oxid. (1 to 1 line)
28-43% (mean)
21-40% (median)
Suggested value = 30%
Theoretical Max.
Oxid. (1 to 1 line)
In reality, a single number is too simple.
% Oxidation depends on the CH4 loading rate to the cover
CH4 oxidation rate
Max rate
CH4 loading to cover

12. Porosity Effects on CH4 Oxidation
The oxidation rate results obtained from the 60-cm-thick cover simulations are essentially the same as the ones obtained from the 30-cm simulations.
Results showed that the thickness of the cover does not change the methane oxidizing capacity of the cover because in does not change the amount of methane that can be oxidized by a cover.

13. Landfill Emissions and Methane Oxidation:
Field-Scale Test Sections Experiment
GRANTEES: Florida State University (Abichou and Chanton)

14. EPA Rule on Methane Oxidation
EREF data and literature values were used to issue a new rule on methane oxidation
Methodology is based on the relation between methane loading to landfill covers and methane oxidation described by EREF data
Site specific methane oxidation that is dependent on methane flux: 0%
10%
25%, or
35%

15. Research Objectives
Assess field-scale methane oxidation using large-scale test pads with interim landfill cover soils
Less than 24 inches thick
Different methane loading flux conditions
Extended period of time to assess the variation due to climate

16. Test Pads in Oregon

17. Results
Test Pad 2
6’’ local soil
12’’ compost

18. Oxidation during Monitoring Duration
Mass balance shows that higher methane oxidation is possible in soil less than 24 inches

19. Accuracy of Whole-Landfill Methane Emissions Estimates with Tracer Dilution Method
GRANTEES: University of Delaware and University of California, Berkeley (Imhoff and Chow)

20. Research Focus and Questions
Field studies in flat terrain validated tracer dilution method for point CH4 sources
Measurement errors for CH4 release from landfills
Transect distance and orientation
Vehicle speed
Misalignment of tracer with CH4
Effect to topography
Address Questions with Wind Modeling at a landfill in Delaware
Emission measurements and wind data
Omparison to1 min

21. Tracer dilution method (TDM) Guidelines
Key Findings
Tracer dilution method (TDM) Guidelines
Center tracer in high CH4 emission regions
Center horizontally
Center vertically
Make measurements downwind as far as possible
Road orientation and vehicle speed not significant source of error
Measurement errors at the studied landfill was ~ 30% or less.
Omparison to1 min

22. Factors Affecting CH4 Emissions
Omparison to1 min
TDM measurements typically 2‐6 hours
• To obtain annual emissions estimates, models needed
that account for changing factors

23. Conclusions Fugitive Emissions Porosity Effects on CH4 Oxidation
Tracer gas and DiAL methods appear to be the most promising approaches for landfill fugitive methane measurement
Porosity Effects on CH4 Oxidation
Thickness of the cover does not change the methane oxidizing capacity of the cover
Landfill Emissions and Methane Oxidation
Mass balance shows that higher methane oxidation is possible in soil less than 24 inches
Whole-Landfill Methane Emissions
Dependency of CH4 emissions on wind speed suggests that care should be exercised in extrapolating whole-landfill emissions measurements made under particular wind conditions to emissions under different atmospheric conditions.

24. Stephanie C. Bolyard, PhD
Questions
Stephanie C. Bolyard, PhD

25. Introduction to EREF Non-lobbying, non-profit charity
Began in 1992
Mission: To fund and direct:
scientific research, and
educational initiatives
for sustainable waste management practices to benefit industry participants and the communities they serve.

26. Methane Oxidation Measurements
Stable carbon (δ13C) and hydrogen (δ2H) isotopes
Mass balance and kinetic approaches
Adds a neutron less abundant so easier to measure.
Green, R. “Project Review: Landfill Emissions and Methane Oxidation: Field-Scale Test Sections Experiment” April 21, 2017