VAMOX Full Scale RTO Technology for the Abatement of VAM Emissions

Global coalmine methane (CMM) emissions from coalmines amount between 1.2 and 1.5 GtCO 2 e each year, depending on the reporting agency. Ventilation Air Methane (VAM) represents some 65% of the total CMM emissions. Until now, its dilute methane concentration varying from 0.1% up to more than 1.5% in some very gassy US coalmines has proven to be a barrier to its recovery and use, whereas low volume high concentration gob and drainage gas have been already used for power generation in USA, Australia and China for example. Destroying VAM results in a net reduction of greenhouse gas (GHG) emissions, which activity can generate in USA bankable carbon credits following the adoption by California Air Resource Board (CARB) of the coalmine methane protocol in 2014 and by Quebec province (Canada) in 2016. Biothermica has commissioned in 2009 a first 30,000 acfm VAMOX ® system on the VAM bleeder shaft 4–9 at Jim Walter Resources (JWR) underground coalmine in Brookwood, Alabama, which was in operation until 2013. Some 80,766 carbon credits were issued under the Mine Methane Capture (MMC) protocol of the California Air Resources Board (CARB) and sold in the carbon cap-and-trade market. It has been followed by the installation and operation of a first 152,000 acfm and a second full scale 180,000 acfm VAMOX ® systems, respectively commissioned in July 2022 and in April 2024 on two different vent shafts at a Virginia (USA) met coalmine. The primary goal of these two recent projects was to demonstrate that a large scale VAMOX ® system can safely, efficiently, and reliably abate VAM emissions while generating a constant revenue stream from the sale of carbon credits. These projects are achieving combined net emission reductions of approximately 500,000 tCO 2 e per annum. The VAMOX ® system uses the principle of regenerative thermal oxidation to convert methane into harmless by-products and can safely operate at a methane concentration between 0.2% and 1.2%, dilution air being introduced in the unit to maintain methane concentration at a maximum of 1.2% if VAM concentration is higher than 1.2%.