Speakeasy Science

The Methane Calculation

Almost 200 years ago, methane gas ignited in a coal mine in England, setting off an explosion that killed 92 miners. These were not miners as we think of them today – in the pre-child-labor-law world almost half were children, as young as eight years old.

So that one can make an argument – regarding last Thursday’s methane gas explosion at the Upper Big Branch mine in West Virginia, that killed 25 adult miners and left another four so far missing – that we’ve made some progress in protecting children from mine disasters. Our track record in protecting adults is less impressive – that is they still work in coal mines and despite more than 200 years of evidence, they still die in methane explosions.

The Upper Big Branch explosion is being described as the worst U.S. mining disaster in more than two decades, topping the methane explosion four years ago at West Virginia’s Sago Mine which killed a dozen workers. But in that time period, even worse methane mining disasters have occurred elsewhere: in 2007, 107 Russian miners died in a blast in a Siberian mine; in 2004, more than 35 workers died in an Ukranian mine explosion caused when methane ignited in a mine shaft.

The explosion in Britain’s Felling mine in 1812 was so powerful that flames roared out of the mine-shaft entrance into the open air. Investigators believed in that case, methane was ignited by candle-lit lamps carried by the miners. The disaster prompted the notable British scientist, Sir Humphrey Davy, to design a “safety lamp” with an enclosed flame – which burned brighter if methane seeped into the lamp – for use in mines. Davie’s lamp greatly reduced but, obviously, didn’t eliminate methane explosions in mines. In the year, 1907, for instance, 362 American miners were killed in a methane explosion in, yes, again, West Virginia.

In an excellent look at methane in coal mines, Thomas Maugh of The Los Angeles Times, points out that the gas is always found in coal mines. It’s produced by the same buried organic material, heat, and underground pressure that creates coal itself. In other words, methane is just another hydrocarbon. It’s chemical formula is CH4, another way of saying that its made of one atom of carbon and four of hydrogen.

The gas is mostly contained in the coal seams until miners drill into them and release it. And, Maugh notes, methane is usually found in greatest concentrations in regions like West Virginia, the sites of ancient swamp-lands that formed a soft, tarry, and gassy layers of bituminous coal. That’s not to say that spectacular mine disasters are limited to methane-rich mine areas. The previous worst disaster in U.S. mining history was the 1984 fire at Utah’s Wilberg mine, reportedly caused by sparks from a faulty compressor, which killed 27 people.

We’ve come far beyond Davy’s safety lamp in detecting a risky methane build up. There are sophisticated detectors; mine operators are supposed to routinely vent the gas out before it reaches explosive levels. What is the chemistry that makes methane so explosive? I’ll be talking about that in tomorrow’s blog.

Today I want only to emphasize that there’s nothing mysterious about the risks of methane blasts in mining. Rather, there’s a long and lethal history, one that tells us over and over again that this is a gas to be treated with extreme respect and handled meticulously. When that doesn’t happen, when people die, the result cannot be dismissed as a natural disaster.

The failure is ours.

Comments

  1. #1 Chris Abouzeid
    April 8, 2010

    Hi Deborah,
    Just picked up your book yesterday, and now I find your blog with a great post on methane and mines. Fascinating! Looking forward to reading more of your work.

    — Chris

  2. #2 admin
    April 8, 2010

    Thanks so much, Chris, and I hope you really enjoy the book. Love to hear what you think of it.

  3. #3 bob mcpherson
    April 11, 2010

    Hi just a quick word on regs in uk mines regarding methane in the mine .Firstly methane ignitions in themself is not usually the cause of the really large explosions what happens is the smaller explosion blows coal dust from the floor roof and sides into the mine atmosphere,this then ignites the airborne coal dust ,coal dust explosions are incredibly powerful many times more than methane to combat this a fine limestone dust is spread on a regular basis and closer toward the coal face it is piled on barriers suspended from the roof. All electrics,eg cutting machines fans,lighting, conveyor drives etc have methanometers built in and cut the power if methane levels reach 1.5 percent, all miners wear self rescuers (masks wiich render through catalicystic covertors carbon monoxide into carbon dioxide in addition all mineworkers attend a compulsary safety day at least once a year . it has been many years (1970’s I think)since we have had any fatality’s through explosions we do though have a fully unionized workforce and safety is paramount .I have 35 years of mining now behind me thank goodness, and am always sadened when i hear of these preventable incedents.

    Bob McPherson

  4. #4 admin
    April 11, 2010

    You make some really terrific points here. Thanks so much for writing about your experience and perspective. I did deal more with methane explosions serving to ignite coal dust in the second of the two columns on this subject. And I completely agree with your point about preventable accidents.

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