Cleaning Up Coal
If you're able to read this story, thank a coal miner. If you're looking at GovExec.com on a computer screen, or paging through the magazine in an artificially lighted space, the energy powering your computer and your lights likely comes from burning coal. Or maybe you're sitting somewhere in the Pacific Northwest where your electricity comes from hydropower, or in Indiana where your electricity comes from a nuclear power plant, or somewhere off the grid where you generate your own power using solar panels. You still can thank a coal miner because this story was written on a computer in a city that depends on coal for electricity and the magazine was printed in a state that depends on coal to power its printing plants.
There's a lot of talk about the security implications of the nation's addiction to foreign oil, but Americans are just as addicted to domestic coal, and the implications could be just as important. More than 50 percent of electricity consumed in the United States comes from coal-fired power plants, a figure Energy Department analysts expect to grow to 57 percent by 2030. And because coal is cheap and plentiful and is mined in America, it will most likely remain an economically and politically irresistible energy source well into the future, as evidenced by the fact that power companies are proposing to build 159 new coal-fired power plants nationwide in the coming years, according to an Energy Department analysis, a potential investment estimated to be worth $141 billion.
It's a prospect that deeply worries many environmentalists. Carbon dioxide emissions are the single-greatest contributor to global warming, and coal-fired power plants account for one-quarter to one-third of man-made carbon dioxide emissions worldwide. With China and India increasingly turning to coal to power their growing economies, the environmental stakes are enormous.
The Energy Information Administration's Annual Energy Outlook 2007 shows that in 2005 the United States mined and burned more than 1.1 billion tons of coal, mostly in Wyoming and West Virginia. The environmental costs are well known and documented: Entire mountaintops in West Virginia have been removed and hundreds of miles of streambeds rerouted and polluted in the mining process; nitrogen oxide, sulfur dioxide, mercury and other byproducts of coal-generated electricity production have degraded air and water quality to harmful levels in numerous locations.
In his State of the Union address in January, President Bush for the first time acknowledged that global climate change is a serious problem. Judging by the administration's 2008 budget proposal for the Energy Department, it's clear Bush is banking on coal to address near-term energy needs. The department's coal program is slated to receive $330 million, more than any other program in the Office of Fossil Energy. The bulk of that money would go to two programs known as the Clean Coal Power Initiative, a industry-government technology demonstration program aimed at reducing toxic and greenhouse gas admissions at existing plants, and FutureGen, a public-private partnership program to build the first coal-fired power plant that produces electricity and hydrogen while reducing carbon dioxide emissions to nearly zero.
While the administration has resisted imposing caps on carbon dioxide (something many people, even in the power industry, believe is essential to drive down greenhouse gas production), Energy Department officials hope that commercial-scale technology demonstration programs under CCPI and FutureGen will prod industry to retrofit existing plants with improved technology and build even cleaner power plants in the future.
Saudi Arabia of CoalThe United States is the Saudi Arabia of coal. With 25 percent of the world's coal beneath its surface, the United States has more than a 200-year supply at current consumption rates, says Thomas A. Sarkus, the FutureGen project director at the Pittsburgh office of the Energy Department's National Energy Technology Laboratory, the only federal laboratory dedicated to fossil fuel research. Compared with petroleum, for which there is an estimated 50- to 60-year supply, and natural gas, which is projected to run out in 20 to 30 years, coal is an attractive fuel from a national security standpoint.
It's also cheap. "The price of coal is always well below the price of oil and gas," Sarkus says. "Not only is it less expensive, but the price is a lot less volatile. Coal companies are willing to enter into supply contracts in the range of 20 to 30 years." Although coal accounts for 80 percent to 85 percent of U.S. fossil fuel resources, it accounts for only about 15 percent of fossil fuel use. "We're relying in inordinate proportion on the resources of which we have the least," Sarkus says. Coal's affordability, economic stability and domestic abundance, coupled with rising electricity consumption in the United States, will increasingly push U.S. coal consumption. The history of the lab's Pittsburgh facility says much about the nation's evolving relationship with coal (the lab also includes research facilities in Morgantown, W.Va.; Fairbanks, Alaska; and Tulsa, Okla.). The lab was created in 1910 by the Bureau of Mines to improve safety conditions after more than 3,000 men were killed in mining accidents the previous year. It is located on the southwest side of Pittsburgh atop what the West Virginia University Natural Resource Analysis Center calls the most valuable mineral deposit in the world. The Pittsburgh coal seam comprises a 1,600-square-mile maze of mines running through Western Pennsylvania, parts of Ohio and West Virginia. Visitors to the lab can still see the opening to an old mine used in early safety experiments. But after World War I, in a nod to the growing strategic value of coal, laboratory scientists began researching ways to make fuel from liquid coal, work that intensified during World War II when the German Luftwaffe used liquid coal to fuel the Battle of Britain. But by the 1970s, when acid rain dampened the country's enthusiasm for coal-generated electricity, the lab's scientists and engineers turned their attention to developing technologies that would reduce pollution from coal-fired electric generating plants. Now part of the Energy Department, the lab is focused not on mining, but on energy production research.
"Environmental matters are probably the single most important factor in what I do," says Sarkus. His background managing programs aimed at reducing acid rain and developing more efficient electricity production plants makes him uniquely qualified to manage the complexities of future energy production (he also is a lawyer and an engineer, with degrees in chemistry, geology, earth science and law). But environmental factors are not the only issues for him. Cheap energy is fundamental to the American economy, and very few politicians, industry leaders or taxpayers want to pay more than they do for electricity. But scrubbing coal clean of toxic byproducts and capturing carbon dioxide emissions is expensive. One of the Energy lab's goals is to develop effective technologies that won't significantly drive up electricity costs.
Obligation and OpportunityThe reasons are both local and global. To Sarkus, the United States has both "an obligation and an opportunity" to help other nations develop energy resources in a way that is less destructive to the environment. "Part of what we're trying to do is to convince them that doing it more cleanly is not necessarily going to hinder their growth," he says. Likewise, Sarkus adds, "There are a lot of people who live on restricted incomes. For those people energy is a bigger part of their economic burden than for the average person. I don't think it's my place to impose on them additional costs unduly."
Coal has been cleaned up considerably over the last two decades. Since the Clean Air Act amendments of 1970 came into force, coal use has tripled, yet emissions of sulfur dioxide and nitrogen oxide have decreased (mercury emissions are just now beginning to be addressed).
One of the complicating factors in developing clean coal technologies is the fact that coal is not a uniform resource. It burns differently, creating diverse byproducts, depending on where it is mined, says Kenneth E. Markel, who directs major clean coal technology demonstration programs aimed at reducing emissions at existing power plants. Many power plants burn only a certain type of coal. What works in Michigan might not work in Texas. "We have to continue to develop and demonstrate a whole suite of technologies" to get industry buy-in, Markel says.
The electric utility industry is inherently conservative and averse to risk, he adds, which further complicates reform. When utility managers have a plant that produces reliable power, they don't like to tinker with it, especially if the tinkering costs money. And just as not all coal is created equal, not all power plants are alike. There are more than 1,100 utility-scale boilers burning coal in the United States, most of which are decades old (very few power plants were built in the 1990s or later, and many of those operating today were built 40 to 50 years ago), so there is a tremendous mishmash of existing technologies.
In addition, state public utility commissions, which regulate the plants and have to approve new construction, often place a higher value on cheap power than clean power, thus further eroding incentives for reducing emissions. The demonstration programs-there have been about 50 to date-were designed to get around those barriers and mitigate risk to industry. By sharing scientific expertise and the financial burden of innovation (the government picks up about 30 percent of the costs on a typical demonstration) the Energy Department is slowly prodding a reluctant industry toward greater efficiency.
Back to the FutureToday's commercial electricity industry traces its roots to Thomas Edison's power generation station on Pearl Street in lower Manhattan. Edison didn't invent the electric light bulb or the power generator, but the Pearl Street station demonstrated their commercial viability in 1882 when Edison was able to provide electric light to one square mile of the city.
Engineers soon found that coal ground to the consistency of talcum powder would burn faster and hotter. The first pulverized coal boilers came on line in the 1920s and the technology in most coal plants operating today, while much improved over the last seven decades, remains essentially the same: typically, pulverized coal is burned in a boiler surrounded by steam tubes. The burning coal heats water, which produces steam that travels through the tubes to turn the blades of a turbine. The turbine is connected to a copper coil that spins within a magnetic field to produce electricity. The steam is then cooled and condensed back into water that will be reheated to continue the process.
In the 1990s, the Energy Department funded a new kind of coal plant. Instead of pulverizing coal to burn it, engineers turned coal into a gas. Coal gasification wasn't new. Long before Edison opened the Pearl Street station, a rough form of gasified coal-called town gas-was used to light streets in many cities. Cleaner natural gas replaced town gas in the United States in the 1940s and 1950s, although it is still burned in China and elsewhere. But the coal gasification plants pioneered by the Energy Department were unique. By gasifying the coal, engineers discovered it could be cleansed of nearly all pollutants, a major breakthrough for controlling emissions. The process, called IGCC for integrated gasification combined cycle technology, is used commercially today at only four plants in the world, two in the United States: one near Tampa, Fla., and another on the Wabash River near Terre Haute, Ind. They are among the world's cleanest power plants, having eliminated more than 90 percent of nitrogen oxide emissions and 98 percent of sulfur from coal. But they also are significantly more expensive to build than pulverized coal plants, which is why there are only two in the country.
Capturing CarbonThe holy grail for clean coal advocates is FutureGen, a 10-year, $950 million project proposed by the Bush administration in 2003. If it comes to fruition, FutureGen will be the world's first zero-emissions coal-fired power plant to produce both electricity and hydrogen while capturing and permanently storing carbon dioxide deep underground.
Building FutureGen is an alliance of government and industry partners, including American coal and electric companies, as well as British, Chinese and Australian power companies.
The plan is to integrate advanced coal gasification technology with combined cycle electricity generation, hydrogen production and carbon sequestration in a commercial-scale operating plant. By doing so, researchers expect to lay the foundation for future energy production on a global scale. The program's ambitious goal is to validate both the technical feasibility and the economic viability of emissions-free power from coal. In the words of an Energy Department brochure, "The success of FutureGen will assure that coal, a low-cost abundant and geographically diverse energy resource, continues to globally supply exceptionally clean energy." That unabashed plug for the coal industry, usually more notable for environmental destruction than for progressive energy policy, worries many environmentalists. They believe banking on fossil fuels of any kind is a Faustian bargain for the planet.
Nevertheless, carbon sequestration has advocates among environmentalists, most notably David Hawkins, director of the climate center at the Natural Resources Defense Council in New York. "Development and use of technologies such as coal gasification in combination with carbon dioxide capture and permanent disposal in geologic repositories under certain circumstances could enhance our ability to avoid a dangerous buildup of this heat-trapping gas in the atmosphere while creating a future for continued coal use," he told members of the House Subcommittee on Energy and Minerals Resources last May. "The conventional coal fuel cycle is among the most environmentally destructive activities on earth. But we can do better with both production and use of coal. And because the world is likely to continue to use significant amounts of coal for some time to come, we must do better. With the right standards and incentives we can fundamentally transform the way coal is produced and used."
Capturing and sequestering carbon isn't entirely new. Oil and gas companies long have pumped it into depleted oil fields to push out hard-to-reach reserves. With FutureGen, the same basic concept would be used, but instead of pumping carbon dioxide into old oil fields, it would be pumped into underground saline aquifers or other geologic formations capable of permanently holding it.
Four sites are currently under consideration for FutureGen, two in Illinois and two in Texas. All have access to what scientists believe would be safe and appropriate options for carbon dioxide storage.
Later this year, after public hearings in all four locations, the FutureGen Alliance will decide where to build the plant. It will function as a research facility as well as a power plant, and is on track to be operational by 2012, says Sarkus. "We're hoping to operate it well enough to show whether these plants are viable in the 2015 time frame," Sarkus says. That would enable building subsequent plants in 2020.
"I'm not so naive as to believe that everything about FutureGen is going to work," Sarkus says. "But some things are going to work and we certainly want those features to be adopted in subsequent power plants."
Coal is basically fossilized plant material that has been buried for millions of years. There are four general types, ranked by carbon content and other properties such as sulfur content and density. The higher the carbon content, the higher the heat value, which is measured in British thermal units-1 Btu is the amount of heat required to raise 1 pound of water 1 degree Fahrenheit. Anthracite is almost pure carbon and remaining reserves are confined to a few counties in northeastern Pennsylvania. About 90 percent of U.S. coal is bituminous or subbituminous, with most of it being mined in Wyoming and West Virginia.
|Anthracite||15,000+ Btus/lb.||Home heating||Northeastern Pa.|
|Subbituminous||8,300+ Btus/lb.||Electricity||West, Ala.|
|Lignite||4,000+ Btus/lb.||Electricity||Texas, Mont., N.D.|