On April 5, 29 coal miners died tragically at Massey’s Upper Big Branch mine. Although the accident was one of the worst in recent history, government figures show that about as many miners die in the United States every year.
While government inspectors and mine owners investigate the lessons of this disaster, some experts are calling for leaving coal in the ground and tapping its energy by drilling instead of mining.
The technique they advocate is called underground coal gasification, or UGC. First suggested in 1868, and touted by Vladimir Lenin in 1913 as a way to free workers from deadly labor in the mines, UCG is now a widely proven, though sparsely deployed, technology.
The concept is to inject oxygen deep into a coal bed until it reacts, forming heat and various gases, including carbon monoxide and hydrogen. The gases can be burned directly for energy, turned chemically into liquid fuels, or used as petrochemical feestocks.
A new draft study issued last week by the National Energy Technology Laboratory on “domestic unconventional fossil energy resource opportunities” lists UCG as one of the most promising technologies.
The report estimates the amount of coal that UCG could tap in the United States at anywhere from 226 billion short tons to 3,600 billion short tons—a huge multiple of the 18 billion short tons of recoverable coal reserves at producing mines.
Plausible estimates for the amount of natural gas that could be created through UCG range from 1,500 trillion cubic feet—equal to all potentially recoverable natural gas in the United States—to more than 30,000 trillion cubic feet. “These are enormous numbers,” the report says, stating the obvious.
The technique has been tested at four sites in the United States, as well as in Australia, South Africa, China, Russia and other countries.
One of the major patent holders on UCG technology is Lawrence Livermore National Laboratory (LLNL).
Studies by LLNL, Ergo Exergy Technologies and GasTech Inc. , which is developing projects in Wyoming, suggest that UCG can be highly competitive in cost and environmental impacts with traditional coal mining and coal-fired generation methods. And the carbon dioxide emitted from the process can be captured more easily than from traditional plants.
Still, unless carbon capture methods are radically perfected, tapping all this fossil energy runs the risk of turning the earth’s climate back to something resembling what it was during the age of the dinosaurs. Unless you have a thick hide and big teeth, you’d better hope UCG becomes just a transitional measure on the way to a post-fossil-fuel world.