Coal may soon be mined without mining
Underground coal gasification is being explored as a way to slash energy costs and increase environmental and human safety.
Mon, Apr 19, 2010 at 06:57 PM
The recent West Virginia coal mine disaster highlights the extreme dangers of traditional coal mining. But researchers in Germany are offering an alternative that may change the future of coal mining. The New York Times reports that a new round of companies and scientist are working to improve the process of underground coal gasification (UCG) as a way to curb greenhouse gases and make mining safer.
What exactly is UCG? Think of it as drilling for coal energy instead of mining for it. It involves baking coal while it is still underground while channeling the CO2 up through turbines to harness the fuel. Using controlled fires and the pressure of gravity, experts predict that coal seams once deemed inaccessible can be turned into fuel. And to fill the holes left in the earth by once-present coal? Miners would inject stabilizing carbon dioxide into the void.
Called “coal energy with a natural gas footprint,” experts argue that this technology would greatly reduce greenhouses gasses while avoiding the dangerous pitfalls of traditional mining. However, UCG remains problematic. Efforts in the 1970s polluted surrounding underground water tables. However, experts say this is now a controllable problem. John Thompson is director of the coal transition program at the Clean Air Task Force, a nonprofit focused on reducing atmospheric pollution. As he told the New York Times, "The big challenge with this environmentally is groundwater damage. But if a site is located below the potable water supply, you really eliminate a lot of the problems that existed in the 1970s."
Contaminated groundwater isn’t the only potential problem. Controlling the underground fires is another issue for UCG. Some scientists are concerned about how heat and the resulting chemical reactions of gasification could change coal seams. Presently, real-world tests still need to be performed to see how earth and gas would react under such conditions.
The concept behind UCG has been around for a century, but scientists only now feel that the technology has advanced enough to safely extract the gas. During the 1970s oil crisis, the U.S. followed Soviet research by drilling 33 pilot projects. In the 1980s, Belgium and Spain hosted projects. Presently, China is embracing UCG technology, with the rest of the world carefully following suit.
In the end, experts feel that UCG will only have success is it is cost-effective. Traditional coal-fire plants cost more than $1 billion when built, while the costs of UCG could come in at several hundred million dollars. But should the first projects go smoothly, experts say the face of coal mining could be changed forever. As Thompson told the NY Times, “it is a very, very attractive way of getting energy out of coal … while also allowing the world to make deep, deep reductions in CO2 by the midcentury."
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