MODERN TIMES

Art Hobson

ahobson@uark.edu

NWA Times 19 January 2008

 

Arkansas Energy Resources:  Lignite

 

              As everybody should know by now, the nation and world are in an energy crisis. 

              World oil resources are at the breaking point.  Production of remaining "conventional" oil from wells will soon reach a peak and then begin a long decline.  Oil prices are already surging as demand increases rapidly while supplies increase slowly.  Prices are now high enough to make "unconventional" oil, from shale and from tar sands, feasible, but producing it is environmentally harmful and increasingly expensive. 

              Conventional natural gas from wells is also strained and so again the price is increasing and companies are looking for unconventional sources.  One such source is gas that is forcibly released from underground shale rock.  A broad band of shale running across the state, known as the "Fayetteville shale," appears to contain a lot of natural gas and is beginning to be commercially exploited.  I hope to report on this development in a later column. 

              The other fossil fuel is coal.  There is a lot of it in the world, much of it in the United States, and we're in no danger of running out anytime this century or probably the next.  The result is that prices have remained steady and coal is our cheapest electric power source.  But coal is arguably the most dangerous substance on the planet right now because it releases so much of the carbon dioxide (CO2) that is primarily responsible for global warming.  More than half of the human-caused CO2 that is now in the atmosphere comes from coal. 

              To get a feel for the damage that can be done by coal, consider the world's roughly 1,000 billion tons of known coal reserves that are economically feasible to recover at today's prices.  If even 30% of those reserves were burned and its carbon released to the atmosphere, this alone would raise atmospheric CO2 concentrations to 450 parts per million, which would push global temperatures up by another 2 Fahrenheit degrees beyond the 1.35 degrees of warming that have already occurred.  Most climate scientists believe this would pose a real danger of launching the Greenland and West Antarctic ice sheets into irreversible melting, raising sea levels by 15 feet by 2100--permanently flooding most of the world's coastal cities--and by 50 feet by 2200.

              Lignite is a soft form of coal, with a relatively low energy content.  Arkansas has 9 billion tons of it buried at shallow depths in 23 southern counties and 3 northeastern counties.  According to researchers at Southern Arkansas University and elsewhere, it could be profitably strip mined and either burned at a power plant near the mine, or turned into a liquid automotive fuel. 

              There are serious problems with either path.

              Three Arkansas cities may cooperate to build a 90-megwatt power plant near Benton, just southwest of Little Rock, fueled by Arkansas lignite.  But global warming makes the future of coal (including lignite) very tenuous.  There is a growing call for a moratorium on new coal-fired power plants until that time ten or more years from now when carbon capture and storage technology can be installed in every new plant to pump 95 percent of its CO2 emissions into underground storage.  This technology is essential if we're to continue using coal.  Such a moratorium is sorely needed and is already partially successful in the sense that many, perhaps most, new plant applications have been rejected in recent years, for environmental and other reasons.

              Carbon storage will increase the cost of using coal, making other options such as wind much more competitive.  Anybody considering lignite needs to reflect on the changed economics of coal in the age of global warming.

              With oil now at $100 a barrel, coal-to-liquids technology can for the first time compete with gasoline.  However, the notion of converting lignite to liquid fuel has even more drawbacks than a lignite-fueled power plant.  The problem is in the emissions stemming from the conversion process.  That process involves first turning the lignite into an energy-rich gas, then turning this gas into a liquid similar to diesel fuel.  The CO2 emissions occurring in this conversion are larger than the emissions from burning the fuel after it gets into a car's gas tank.  The result is that the net CO2 emissions from "liquid coal" are more than twice as large as the emissions from gasoline. 

              This technology will be a global warming disaster.  Liquid coal is probably the only energy resource that's worse than the direct burning of coal.  It's economics are likely to be drastically changed by any Congress that takes the environment seriously. 

              To learn more about global warming, attend the "Focus the Nation" events of January 30 and 31.  Focus the Nation is a global warming "teach-in" occurring on hundreds of college campuses, including ours.  On January 30 at 6:30 pm in the Arkansas Union Theater there will be a keynote address followed by discussion and a webcast of "The Two Percent Solution" to global warming.  There will be a free-for-all forum all day long on January 31 in the Arkansas Union Connections Lounge followed by a panel discussion from 4 to 5:30 pm in the Reynolds Center. 

              The planet has far more fossil fuel than it can possibly use without wrecking the environment.  Sure, we can, for a little while longer, continue driving our SUVs and building new superhighways as though there were no tomorrow.  But in fact nature has her limits, and those who dream of endless consumption had better learn to respect those limits or the human experiment with technology will fail.

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