Biothermica

The Vamox® RTO solution

The Vamox® RTO solution creates opportunities to value Ventilation Air Methane (VAM), a wasted resource, by generating carbon credits and/or power.

What is VAM?

Coal mining activities release a large amount of methane. As methane is a potent greenhouse gas (GHG) with a global warming potential (GWP) 25 times that of carbon dioxide, it is estimated that global annual methane emissions from coal mining could represent more than 1 billion tons carbon dioxide equivalent.

Underground mines are by far the largest source of fugitive methane emissions in the coal sector, representing about 90% of total emissions.

The control of methane concentrations underground is crucial to ensure the safety of miners. Two methods are used:

• Ventilation
• Gas drainage

VAM (Ventilation Air Methane)

A large volume of air is circulated throughout the mine working area to dilute methane concentrations below explosive levels.

High-powered exhaust mine fans vent this air to the atmosphere.

• ~70% of global coal mining emissions come from VAM
• Estimated emissions: ~700 MtCO₂e per year
• Methane concentration: typically < 1%

Despite containing significant energy, this low concentration has limited its use.

👉 The Vamox® RTO solution developed by Biothermica enables:

• Carbon credit generation
• Energy recovery

Drainage Gas (Coal Mine Methane)

Drainage systems supplement ventilation by removing methane before or after mining.

These systems:

• Use boreholes (surface or underground)
• Capture methane from coal seams and surrounding strata

Captured gas is called Coal Mine Methane (CMM).

Unused CMM can be:

• Mixed with VAM
• Used to regulate methane concentration
• Improve project profitability

Generating Carbon Credits from VAM

Since VAM abatement is not mandatory, carbon credits are the main incentive.

• Methane is 25× more potent than CO₂
• Each ton of methane oxidized = 22.25 tCO₂e reduction

Policy Support

• California adopted the Mine Methane Capture Protocol (July 1, 2014)

• Enables carbon credit generation under cap-and-trade

• Québec has also implemented a similar protocol

Economic Viability

• Required carbon price: ~$10–$12/tCO₂e
• Recent prices have exceeded this threshold

Currently, only:

• United States
• Canada

have strong enough carbon markets to support standalone VAM projects.

U.S. VAM Data (EPA)

• Total emissions: 2.4 MCM methane
• 29 vent shafts economically viable (> ~0.4% methane)

Generating Power from VAM

Even at low concentration, VAM contains significant energy.

Example:

• 300,000 scfm airflow
• 1% methane concentration
• ≈ 50 MW thermal energy

Energy Recovery Methods

1. Heat Recovery

• Heat exchangers recover low-grade heat
• Used for district heating

2. Organic Rankine Cycle (ORC)

• Converts waste heat into electricity

3. Steam Cycle (Preferred)

• Uses high-grade heat from combustion chamber
• Maximizes power generation

Learn More

CLICK HERE to request a document presenting an overview of waste heat recovery strategies for a Vamox® RTO.