Methodologies for measuring fugitive methane emissions from landfills - A review

Area of Science:

• Environmental Science
• Atmospheric Science
• Geoscience

Background:

• Fugitive methane (CH4) emissions from landfills are significant contributors to global greenhouse gas emissions.
• Accurate CH4 emission data are vital in Europe for regulatory reporting, model evaluation, and mitigation assessment.

Purpose of the Study:

• To provide a comprehensive overview of methodologies for measuring fugitive CH4 emissions from landfills.
• To discuss the advantages and limitations of various CH4 measurement techniques based on existing literature.

Main Methods:

• Review of published literature on landfill CH4 emission measurement techniques.
• Analysis of methods including tracer gas dispersion, differential absorption LiDAR (DIAL), aerial surveys, eddy covariance, static mass balance, and surface flux chambers.

Main Results:

• Downwind methods (tracer gas dispersion, DIAL) are recommended for accurate whole-site CH4 quantification.
• Aerial surveys combined with wind field data show future potential for cost-efficient quantification.
• Continuous monitoring methods (eddy covariance, static mass balance) are necessary for temporal analysis but face challenges with topography and spatial heterogeneity.
• Surface flux chambers are widely used but likely underestimate emissions due to localized hotspots and uncaptured well/vent emissions.

Conclusions:

• Accurate landfill CH4 emission quantification requires careful selection of measurement techniques based on specific goals (whole-site vs. temporal) and landfill characteristics.
• Future research should focus on integrating aerial and continuous monitoring methods for improved accuracy and cost-effectiveness.
• Understanding the limitations of each method is crucial for reliable emission reporting and mitigation evaluation.