Coal

Coal               Metamorphic product of more or less distinctly stratified plant remains that readily burns owing to a high percentage of carbon compounds. Coal is a solid, brittle, combustible carbonaceous rock formed by partial to complete decomposition of vegetation in situ; that statement is known with considerable certainty since at numerous locations throughout the world carbonized roots found in coal beds extend from the coal seam into underlying sedimentary strata, usually shale. Coal varies in color from dark brown to black; it is not fusible without decomposition and is very insoluble. As organic materials accumulate in bogs and other wet environments of deposition, partial decay of the vegetation uses up much of the oxygen. When the area of deposition is buried by mud and silt, oxygen is sealed out. Continued burial compresses the organic material, driving out water and other volatiles. Though that process, the original peat is transformed into brown and black coal as the carbon content increases.

The two principal methods of classifying coal are by type and rank. Since more people are familiar with coal ranking (for example anthracite), I’ll start with the least well-known system. Geologists classify coal according to organic debris, called macerals, from which the coal is formed. Macerals are identified microscopically to determine individual components and the way they combined to form the coal. The purpose of classifying coal by type is to determine the chemical composition of major deposits, including sulfur and ash content, which then must be matched to the most suitable end uses. Author’s Note: In 1904, Marie Charlotte Stopes earned a PhD in the field palaeobotany at the University of Munich and a D.Sc. degree from University College London, becoming the youngest person in Britain to have done so. In the mid-1910s she worked on a system of coal petrology that has become standard in the geosciences and coined the term maceral as a unit of coal composition, describing it as the equivalent of the inorganic materials composing rock masses called minerals. Even more interesting is that Stopes was a militant feminist, a pioneer in the emerging field of birth control, a supporter of the eugenics movement, and founder of the Marie Stopes International global partnership that focused on sexual and reproductive health. In 1921, Stopes opened the UK's first family planning clinic. She eventually stopped working as a scientist to concentrate on women’s rights. Who says geoscientists aren’t a fascinating lot?

But most people are familiar with the other way to classify coal, which is by the degree of coalification (increase in organic carbon content) attained by a given coal owing to burial and metamorphism. From the highest rank to the lowest, coal is classified as anthracite, bituminous, sub-bituminous, and lignite. Those ranks reflect progressive states of metamorphism that have an important bearing on the coal’s physical and chemical properties. Low rank coals, such as lignite and sub-bituminous, have typically softer, friable materials with a dull, earthy appearance. They are characterized by low carbon content and high moisture levels, which translate into low energy output. Higher rank coals are typically harder and stronger and often have a black vitreous luster. Increasing rank is accompanied by a rise in carbon and energy content and a decrease in moisture.

Anthracite has the highest fixed carbon content, between 86 and 98 percent, and a heat value of nearly 15,000 BTUs-per-pound. It is the most highly metamorphosed form of coal and exhibits black, hard, and glassy characteristics. Anthracite is the highest coal rank but is rare in the U.S., supplying a small part of the U.S. coal market. It is most frequently associated with home heating. As a result of the metamorphic process, anthracite contains molecules that are unburnable. Therefore, although its carbon content exceeds that of all other types of coal, its BTU values may be slightly lower than the highest grade bituminous coals. Real World Examples: Approximately seven billion tons of U.S. anthracite reserves are largely located in northeastern Pennsylvania, but those deposits are relatively high in sulfur and will have limited demand until technology makes them more attractive. Anthracite reserves in Poland are estimated at 45.4 billion tons. With current annual production of over 102 million tons (in 2000), the three major coalfields will easily meet that country’s demand for almost 500 years, which is twice as long as the world’s average. One mine in the Lublin Upland, Bogdanka, is the most modern and profitable mine in the country, producing 4.25 million tons of coal in 2000. Author’s Note: The word anthracite is probably derived from Greek anthrakitis, a kind of coal, or from another Greek word, anthrak, charcoal.

Bituminous coal is formed by an intermediate degree of metamorphism and contains 15 to 20 percent volatiles, a carbon content ranging from 45 to 86 percent carbon, and heat values from 10,500 to 15,500 BTUs-per-pound. It is the most common grade of coal in the United States and is used primarily to generate electricity and as coke in steel manufacturing. Bituminous coal predominates in the Eastern and Mid-Continent coal fields where West Virginia and Kentucky are the largest producers. But much of those deposits have high sulfur content, making their widespread use problematic until more cost-efficient removal technologies are available. Canada is also a major coal producing and consuming nation, producing about 70 million tons annually from reserves estimated at nine billion tons, of which more than 50 percent is bituminous. The main coal producing regions are in Alberta, British Columbia, and Saskatchewan in the order of importance.

Sub-Bituminous coal ranks below bituminous with 35 to 45 percent carbon content and a heat value between 8,300 and 13,000 BTUs-per-pound. Reserves are located mainly in a half-dozen Western states and Alaska. Although its heat value is lower than other types, this coal generally has a lower sulfur content, which makes it attractive for use because it is cleaner burning. By far the largest producer of sub-bituminous coal is Wyoming, which produces more coal of any rank than the next two major coal states together (West Virginia and Kentucky).

Lignite, also known as brown coal, is geologically young coal that has the lowest carbon content, about 25 to 35 percent, and a heat value ranging between 4,000 and 8,300 BTUs-per-pound. Mainly used for electric power generation, most lignite in the U.S. is mined in Texas but large deposits are found in Montana, North Dakota, and some Gulf Coast states.

Real World Problems: Historically, coal mining has been associated with various medical problems — see below, Coal: Challenges for the Near Future — not to mention such related historical issues as mine safety and the formation of labor unions. Two very serious diseases that have been closely associated with coal mining until several decades ago are black lung disease (properly known as pneumoconiosis) and silicosis. Pneumoconiosis, a lung condition caused by the inhalation of dust, is characterized by formation of scarring (medically known as nodular fibrotic changes) in lung tissues. Many mineral substances can cause pneumoconiosis, including those that contain asbestos, coal, silica, talc, and various metallic ores. Black lung disease, known as coal miners’ pneumoconiosis, is caused by long exposure to coal dust. Since coal dust that enters the lungs can neither be destroyed or removed by the body, it remains, causing inflammation and fibrosis and turning the lung tissues black, whence its name. The most usual symptom is shortness of breath; the disease can also lead to chronic pulmonary obstructive disease (COPD), emphysema, and heart failure. It once was a common affliction of coal miners and others who worked with coal and was especially severe in those workers also exposed to the long term effects of tobacco smoking. Silicosis is a lung disease that typically affects miners of coal and other minerals caused by inhaling silicon dioxide or crystalline silica dust without adequate masks or breathing apparatus. Acute silicosis is lung inflammation caused by intense exposure to silica over several months. Chronic silicosis, in contrast, is when lung scarring, nodules, and inflammation develop as a result of decades of exposure to silica dusts, gradually causing the lung cells to digest themselves. The different kinds of silicosis are dependent on the type of dust (such as from working decorative stone, chert and flint, or mining igneous and metamorphic rocks containing silica). The disease occurs mainly in people who work in sandblasting, mining, quarrying, grinding, and in foundries.

Both pneumoconiosis and silicosis are less common today than 50 years ago owing to Occupational Safety and Health Administration (OSHA) regulations that require protective equipment for miners and mine safety programs. That said, although stringent occupational reforms have largely eliminated silicosis in Europe, the National Institute for Occupational Safety and Health (NIOSH) estimates that approximately one million U.S. workers remain at risk to silicosis, 100,000 of whom are at high risk. Of that number, adverse health effects are anticipated to develop in 59,000 workers. Other medical problems associated with the combustion of coal in electrical power generating and other industrial plants are discussed below in Coal: Challenges for the Near Future. Fun Stuff: Don’t be fooled by the phantasmagoric term, pneumonoultramicroscopicsilicovolcanoconiosis, or variants thereof; they are merely hoaxes created by scoundrels desperate to beat their competition in word games.

Coal: Challenges for the Near Future[1]             As of the late-2000s, coal supplies more than half the energy needed to run American lights, computers, blow dryers, garage door openers, MRI and X-ray machines, air conditioners, and nearly everything modern society uses that is powered by electricity. Coal consumption is doubling as a result of many factors, including the rapidly rising costs of oil and natural gas, our eagerness to develop a homegrown energy source to compete with and hopefully replace at least part of the OPEC oil we have grown to hate, and the currently fossil fuel-friendly mood that has come to dominate Washington politicians. Because the federal government has chosen not to encourage, incentivize, or develop large-scale alternative energy sources, coal has jumped into first place as the primary fuel for at least the first half of the 21^st Century for generating electricity. In the past decade, coal corporations, commodity markets, investor-owned utilities, an army of lobbyists, and elected representatives at state and national levels (their hands greedily held out for munificent campaign contributions) have interacted to produce a national climate infused with false patriotism that tilts the playing field toward increased mining and coal-fired electrical power plants.

And what is wrong with that, people might ask. The big drawback is that coal-fired power plants are one of the largest manmade sources of carbon dioxide, nitrogen oxide, sulfur dioxide, mercury, particulates, and other gases responsible for global warming. A directly related and critical problem is that alternative energy sources are not expected to contribute significantly to U.S. energy needs in the near or mid-term future, which leaves coal in a league by itself.

As of mid-2006, executives from the largest coal producers and consumer groups have been locked in a struggle to determine the future of coal mining and electrical power production in the U.S. Those players include the chief executive of Peabody Energy, the largest private-sector coal producer in the world (in 2005, Peabody sold 240 million tons of coal), and the CEO of American Electric Power, the nation’s largest coal consumer and biggest producer of heat-trapping carbon dioxide emissions. The two men are pushing the coal-consuming, electrical generating industry along divergent paths that have drastically different outcomes for the environment and for public health. Peabody Energy is not only actively promoting the rising demand for coal but also backs industry-supported organizations that are working to prevent government regulations that require mandatory reductions in emissions of the so-called greenhouse gases. Peabody is also pushing for the construction of new conventional coal-fired electrical plants that would not be equipped with modern technology, known as the integrated gasification combined cycle (IGCC), which would make the future reduction of carbon dioxide and other pollutants easier. It should come as no surprise that the Center for Responsive Politics, which according to its web site is a “non-partisan, non-profit research group based in Washington, D.C. that tracks money in politics and its effect on elections and public policy,” identifies the coal industry lobby as one of the largest contributors to federal political candidates and parties, donating almost $31 million in the 2008 elections with the far greater majority going to Republicans. There’s a shock.

On the other hand, American Electric Power is leading what is still a minor charge within the energy industry to embrace the new IGCC technology. Under the direction of CEO Michael G. Morris, AEP plans to build at least two 600-megawatt plants in Ohio and West Virginia at an estimated cost of as much as $1.3 billion each. The upside is that, according to the USGS, using similar technology AEP’s existing coal-fired power generating plant at Brilliant, Ohio, has cut sulfur dioxide emissions by 90 percent, nitrogen oxides by 50 percent, and carbon dioxide by 15 percent. Naturally, the rub is that conventional power generating plants cost less and take less time to build than those employing the IGCC technology, which is certainly why companies not interested in reducing pollutants advocate them.

Now that coal is favorably priced with regard to oil and natural gas, Peabody has entered the power-plant business, setting out to build two of the largest in the world, the 1,600-megawatt Prairie State Energy Campus in southern Illinois (near the small town of Lively Grove), using six million tons of coal annually produced from one of its adjacent underground mines and the 1,500-megawatt Thoroughbred Energy Campus in western Kentucky (Muhlenburg County), which would also use local coal for its power source. Not surprisingly, given its public record of political campaign contributions, Peabody does not regard government regulation of near-term caps on carbon emissions as a significant threat, despite coal-fired power plants being the U.S.’s largest source of greenhouse gas emissions, which are the primary contributor to global warming.

According to estimates provided by the not so coal-friendly Royal Dutch Shell, a typical 500-megawatt coal-fired electrical generating plant that supplies sufficient power to run approximately 500,000 homes produces as much pollution annually as about 750,000 cars. If you multiply those emissions by three, you get a quick and dirty estimate of how much pollution a 1,500 megawatt plant would produce. Additional air pollution (sulfur dioxide, nitrogen oxide, carbon dioxide, mercury, selenium, and particulates) from even the cleanest conventional coal-burning power plants translates into reduced lung function, lost work time, more visits to the doctor’s office and emergency rooms, and more hospitalizations for asthma, chronic bronchitis, chronic obstructive pulmonary disease, emphysema, and cardiovascular disease, which translates into higher health insurance premiums for those who are insured and higher taxes for everyone to cover the health costs of the uninsured. And that assessment doesn’t include the nearly 24,000 early deaths from people at risk from breathing air polluted by coal-fired plants.

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[1] Be warned: this definition is an extended Author’s Rant.