Coal Mine Methane Sources
- Active Underground Mines
- Active Surface Mines
- Ventilation Air Methane (VAM)
- Abandoned Underground Mines
Coal mine methane (CMM) refers to methane released from the coal and surrounding rock strata due to mining activities. In underground mines, it can create an explosive hazard to coal miners, so it is removed through ventilation systems. In some instances, it is necessary to supplement the ventilation with a degasification system consisting of a network of boreholes and gas pipelines. In abandoned mines and surface mines, methane might also escape to the atmosphere through natural fissures or other diffuse sources.
Coal mine methane is emitted from five sources:
- Degasification systems at underground coal mines (also commonly referred to as drainage systems). These systems may employ vertical and/or horizontal wells to recover methane in advance of mining (known as "pre-mine drainage") or after mining (called "gob" or "goaf" wells)
- Ventilation air from underground mines, which contains dilute concentrations of methane
- Abandoned or closed mines, from which methane may seep out through vent holes or through fissures or cracks in the ground
- Surface mines, from which methane in the coal seams is directly exposed to the atmosphere
- Fugitive emissions from post-mining operations, in which coal continues to emit methane as it is stored in piles and transported
Active Underground Mines
- Identifying Opportunities for Methane Recovery at U.S. Coal Mines: Profiles of Selected Gassy Underground Coal Mines 2002-2016 (July 2019)
- Coal Mine Methane Recovery at Active and Abandoned U.S. Coal Mines: Current Projects and Potential Opportunities (July 2019)
- Case Study: Methane Recovery at Non-Coal Mines (September 2013)
Active Surface Mines
- U.S. Surface Mines Emissions Assessment: Update (February 2015)
- Case Study: Methane Recovery at Surface Mines in the United States (March 2014)
- U.S. Surface Coal Mine Methane Recovery Project Opportunities (July 2008)
Ventilation Air Methane (VAM)
- Ventilation Air Methane (VAM) Utilization Technologies (July 2019)
- U.S. Underground Coal Mine Ventilation Air Methane Exhaust Characterization (August 2017)
- A 2012 Update on the World VAM Oxidizer Technology Market (June 2012)
- Ventilation Air Methane Measurement Methodologies (February 2011)
- Coal Mine Ventilation Air Emissions: Project Development Planning and Mitigation Technologies (August 2010)
Abandoned Underground Mines
- Abandoned Coal Mine Methane Opportunities Database (July 2017)
- U.S. Abandoned Coal Mine Methane Recovery Project Opportunities (July 2008)
- Proposed Methodology for Estimating Emission Inventories from Abandoned Coal Mines (October 2004)
- Methane Emissions from Abandoned Coal Mines in the U.S.: Emission Inventory Methodology and 1990-2002 Emissions Estimates (April 2004)