Some mines capture the methane that is released from some coal, but others simply vent it. It seems to me that that is a waste of fuel, and since methane is a much more portent GHG, contributes to global warming. Why do companies like Massey allow methane to build up to dangerous levels?
It is possible that capturing the methane for sale costs more than they can sell it for.
Massey should have been venting the methane. Mines have huge fans to help put fresh air in and remove stuff they don’t want. Presumably some equipment here failed.
One would also think they would have methane detectors in the mine that sets off alarms if the level gets too high. Or at least some canaries every 100 feet.
You don’t have to be an expert to know it’s going to be all about economics. If they could make money capturing and selling the methane, they’d have started doing it ages ago.
They do have gas monitors that look for firedamp [methane], stinkdamp [hydrogen sulphide], sulphur dioxide, carbon dioxide and carbon monoxide, all of which can kill you. There are also portable detectors. They monitor the percentage of gases over time - small traces may be allowable but over the time period there are average allowable figures.
Afterdamp [products of firedamp and/or coal dust explosion] contains many of these gases and some others.
The methane found in mines will probably be in a very impure form and would not be worth trying to capture for sale.
It’s possible that capturing the methane for sale would interfere with the safe extraction of coal. You need to ventilate the operating areas of the mine so that miners can work safely there, and that’s probably inconsistent with getting the methane for use as a fuel or chemical.