chapter 4
COAL

A HISTORICAL PERSPECTIVE

Although it had been used to create energy for centuries, the first large-scale use of coal occurred during the Industrial Revolution in England from the mid-eighteenth to the mid-nineteenth centuries. At that time the sky was filled with billowing columns of black smoke, soot covered the towns and cities, and workers breathed the thick coal dust swirling around them. Most people then were not concerned with environmental issues because the Industrial Revolution meant jobs to the workers, and factory owners had little desire to control the pollution their factories were creating. In addition, environmental and public health considerations were not as well understood as they are today.

In the United States early colonists used wood to heat their homes because it was so plentiful and coal was less available. Prior to the Civil War (1861–65), some industries used coal as a source of energy, but its major use began with the building of railroads across the country. After the Civil War ended, the United States began to expand its railway system westward and increase its manufacturing capacity. Coal became such a fundamental part of American industrialization that some have called this era the Coal Age. As in England, Americans considered the development of industry a source of national pride. Photographs and postcards of the time proudly featured railroad trains and steel mills with smokestacks belching dark smoke into gray skies.

By the early twentieth century coal had become the major fuel source in the United States, accounting for nearly 90% of the nation's energy requirements. As oil began to heat homes and offices, however, and the growing number of cars used gasoline, coal's dominance declined. By the end of World War II (1939–45), it accounted for only 38% of the energy consumption. Coal fell further out of favor as an energy source in the 1950s and 1960s as oil became more attractive as a cleaner fuel for heating homes and businesses. The decline of coal use continued, with coal producing as little as 18% of the energy used during some years in the early 1970s because of concerns about environmental pollution and the emergence of nuclear power as a promising energy source.

By 1973, however, Americans recognized they could no longer rely on imported oil for their energy. The OPEC oil embargo clearly demonstrated the nation's heavy reliance on foreign sources of energy and its potentially crippling effect on the American economy. Consequently, the nation revived its interest in domestic coal as a plentiful and economical energy source.

After the 1973 embargo, coal and nuclear fuel received more attention, especially in the electric utility sector. In 1977 President Jimmy Carter called for a two-thirds annual increase in national coal production by 1985. He also asked utility companies and other large industries to convert their operations to coal and proposed a ten-year, $10 billion program to encourage domestic coal production. In 2003 more coal was produced within the United States than any other form of energy, generating 22.3 quadrillion Btu and 32% of all energy produced. (See Figure 1.4 in Chapter 1.) Coal was the second largest source of energy consumed in the United States in 2003, after petroleum.

WHAT IS COAL?

Coal is a black, combustible, mineral solid that develops over millions of years from the partial decomposition of plant matter in an airless space, under increased temperature and pressure. Coal beds, sometimes called seams, are found in the earth between beds of sandstone, shale, and limestone and range in thickness from less than an inch to more than one hundred feet. Approximately five to ten feet of ancient, composted plant material have been compressed to create each foot of coal.

Coal is used as a fuel and in the production of coke (the solid substance left after coal gas and coal tar have been

FIGURE 4.1

extracted), coal gas, water gas, and many coal-tar compounds. When coal is burned, its fossil energy—sunlight converted and stored by plants over millions of years—is released. One ton of coal produces an average of 22 million Btu, about the same heating value as 22,000 cubic feet of natural gas, 159 gallons of distillate fuel oil, or one cord of seasoned firewood. (A cord is a stack of wood four feet by four feet by eight feet, or 128 cubic feet.)

CLASSIFICATIONS OF COAL

There are four basic types of coal. Classifications, or "coal ranks," are based on how much carbon, volatile matter, and heating value are contained in the coal.

• Anthracite, or hard coal, is the highest ranked coal. It is hard and jet black, with a moisture content of less than 15%. Anthracite is used mainly for generating electricity and for space heating. It contains approximately 22 to 28 million Btu per ton, with an ignition temperature of approximately 925 to 970 degrees Fahrenheit. Anthracite is mined mainly in northeastern Pennsylvania. (See Figure 4.1.)
• Bituminous, or soft coal, is the most common coal. It is dense and black, with a moisture content of less than 20% and an ignition range of 700 to 900 degrees Fahrenheit. Bituminous coal is used to generate electricity, for space heating, and to produce coke. Bituminous coal contains a heating value range of 19 to 30 million Btu per ton. It is mined chiefly in the Appalachian and Midwest regions of the United States. (See Figure 4.1.)
• Sub bituminous coal, or black lignite, is dull black in color and generally contains 20 to 30% moisture. Black lignite is used for generating electricity and for space heating. It contains 16 to 24 million Btu per ton. Black lignite is mined primarily in the western United States. (See Figure 4.1.)

TABLE 4.1

• Lignite, the lowest ranked coal, is brownish-black in color and has a high moisture content. It tends to disintegrate when exposed to weather. Lignite is used mainly to generate electricity and contains about 9 to 17 million Btu per ton. Lignite has an ignition temperature of approximately 600 degrees Fahrenheit. Most lignite is mined in North Dakota, Montana, Texas, California, and Louisiana. (See Figure 4.1.)

Bituminous coal accounts for the largest share of all coal production; sub bituminous is second. (See Table 4.1.) In 2003 production of all types of coal totaled nearly 1.1 billion short tons. (A short ton of coal is 2,000 pounds.) Of that, nearly 1 billion short tons (92%) were bituminous and sub bituminous coal. Lignite and anthracite accounted for the remainder.

LOCATIONS OF COAL DEPOSITS

Coal is found in about 13%, or 458,600 square miles, of the total land area of the United States. (See Figure 4.1.) Geologists have divided U.S. coalfields into three geographical zones: the Appalachian, Interior, and Western regions. The Appalachian region is subdivided into three areas: Northern (Ohio, Pennsylvania, Maryland, and northern West Virginia); Central (Virginia, southern West Virginia, eastern Kentucky, and Tennessee); and Southern Appalachia (Alabama). Coal production in the Interior region occurs in Illinois, Indiana, western Kentucky, Iowa, Missouri, Kansas, Arkansas, Oklahoma, Louisiana, and Texas. The Western region includes the Northern Great Plains (Montana, Wyoming, northern Colorado, and North and South Dakota), the Rocky Mountains, the Southwest (southern Colorado, Utah, Arizona, and New Mexico), and the Northwest (Washington and Alaska).

Historically, more coal has been mined east of the Mississippi River than west of the Mississippi, but the West's proportion of total production has increased almost every year since 1965, overtaking the east in 1999. (See Table 4.1.) In 1965 the production of coal in the West was 27 million short tons, only 5% of the national total. By 1999 western production had increased more than twenty-fold, to 570.8 million short tons, or 52% of the total. The amount of coal mined east of the Mississippi that year was 529.6 million short tons. In 2003 slightly more than 601 million short tons of coal were mined west of the Mississippi, while slightly more than 468 million short tons were mined to the east. Western production neared 56% of the total mined.

The growth in coal production in the West has been partly the result of environmental concerns that have led to an increased demand for low-sulfur coal, which is concentrated in the West. In addition, surface mining, which is cheaper and more efficient, is more prevalent in the West. Finally, improved rail service has made it easier to deliver this low-sulfur coal to utility plants located east of the Mississippi River.

COAL MINING METHODS

The method used to mine coal depends on the terrain and the depth of the coal. Prior to the early 1970s, most coal was taken from underground mines. Since that time, however, coal production has shifted from underground mines to surface mines. (See Table 4.1 and Figure 4.2.)

Underground mining is required when the coal lies deeper than 200 feet below ground level. The depth of most underground mines is less than 1,000 feet, but a few go down as far as 2,000 feet. In underground mines some coal must be left untouched in order to form pillars that prevent the mine from caving in. In both underground mines and surface mines, natural features such as folded, faulted, and interlaid rock strata reduce the amount of coal that can be recovered.

Surface mines are usually less than 200 feet deep and can be developed in flat or hilly terrain. Area surface mining is practiced on large plots of relatively flat ground, while contour surface mining follows coal beds along hillsides. (See Figure 4.3.) Open pit mining is used to mine thick, steeply inclined coal beds and uses a combination of contour and area mining methods.

FIGURE 4.2

The growing prevalence of surface coal mining and the closing of nonproductive mines led to increases in coal mining productivity through the 1980s and 1990s. (See Figure 4.4.) In 2000 average productivity reached an all-time high of seven short tons per miner hour. Productivity dipped a bit in 2001 and 2002, but by 2003 it had nearly returned to the 2000 level. Because surface mines are easier to work, they average up to three times the productivity of underground mines. In 2003 the productivity for surface mines was 10.7 short tons of coal per miner hour, while underground mines produced 4.1 short tons per miner hour, as reported in the Annual Energy Review 2003, published in 2004 by the Energy Information Administration (EIA) of the U.S. Department of Energy (DOE).

COAL IN THE DOMESTIC MARKET

Overall Production and Consumption

The EIA noted in its Annual Energy Review 2003 that the nation consumed 558.4 million short tons of coal in 1974. Twenty-nine years later, in 2003, consumption had grown to nearly 1.1 billion short tons. (Figure 4.5 shows the flow of coal in 2003.) The increases in coal consumption were greatest in the electric utility sector, as many existing electric power plants switched to coal from more expensive oil and gas, and many new, coal-fired power plants were constructed in the 1970s.

Coal Consumption by Sector

To make electricity, coal is pulverized and burned to produce steam, which then drives electric generators.

FIGURE 4.3

Each ton of coal used by an electric generator produces about 2,000 kilowatt-hours of electricity. In household terms each pound of coal produces enough electricity to light ten 100-watt light bulbs for one hour.

Electric utility companies are by far the largest consumers of coal today. (See Figure 4.5 and Figure 4.6.) They accounted for 92% of domestic coal consumption, or 1 billion short tons, in 2003. Coal-fired plants produced nearly 22.3 Btu of electricity, or 40% of U.S. electricity net generation, in 2003. (See Figure 1.5 in Chapter 1.)

The industrial sector was the second-largest consumer of coal in 2003, accounting for 8% of coal use (see Figure 4.6), or 85.4 million short tons. Coal is used in many industrial applications, including the chemical, cement, paper, synthetic fuels, metals, and food-processing industries.

Coal was once a significant fuel source in the residential and commercial sector. (See Figure 4.6.) In 1949 these sectors used 116.5 million short tons of coal. After the late 1940s, however, coal was replaced by oil, natural gas, and electricity, which are cleaner and more convenient. By 1970 only 16.1 million short tons of coal were used in the residential and commercial sectors. Since then, residential and commercial coal use has continued to decline, falling to 4.5 million short tons in 2003, or far less than 1% of total coal use.

The Price of Coal

In 2003 the average price of coal fell to $17 per short ton, up slightly from the all-time low in 2000 and only 33% of the 1975 price in real dollars, which are adjusted for inflation. (See Table 4.2.) On a per-Btu basis, coal remains the least expensive fossil fuel. In 2000 the average cost of coal was $1.27 per million Btu, compared with $5.68 per million Btu for natural gas and $4.74 per million Btu for residential fuel oil, according to the Annual Energy Review 2003.

ENVIRONMENTAL AND HEALTH CONCERNS ABOUT COAL

Problems

The negative side of energy use—pollution of the environment—is not a recent problem. In 1306 King Edward I of England so objected to the noxious smoke from London's coal-burning fires that he banned coal's use by everyone except blacksmiths. The enormous scale of today's energy use has increased environmental concerns.

Coal-fired electric power plants emit gases that are harmful to the environment. Scientists believe that burning huge quantities of fossil fuels causes the "greenhouse

FIGURE 4.4

effect," in which gases from the fuels trap heat in the earth's atmosphere and cause increased warming, which threatens the environment. Burning coal also contributes to the formation of acid rain and to public health concerns. Sulfur dioxide, for instance, has been shown to cause respiratory problems.

Carbon dioxide accounts for the largest share of greenhouse gas emissions. In 2002 the combustion of coal in the United States produced 2.1 billion metric tons of carbon dioxide, or 36% of total carbon dioxide emissions from all fossil fuels used in the United States. (See Figure 4.7.)

acid rain. Acid rain is any form of precipitation that contains a greater-than-normal amount of acid. Even nonpolluted rain is slightly acidic (with a pH of about 5.6) because rainwater combines with the carbon dioxide normally found in the air to produce a weak acid called carbonic acid. But pollutants in the air can increase the acidity of rain and other forms of precipitation, such as snow and fog.

Chemicals such as oxides of sulfur and nitrogen, which are given off during the combustion of fossil fuels, are pollutants that combine with precipitation to form acids. These oxides increase in the air because of automobile exhaust, industrial and power plant emissions, and other fossil fuel combustion processes. In many parts of the world acid rain has caused significant damage to forests, lakes, and other ecosystems.

FIGURE 4.5

TABLE 4.2

health issues. Emissions from coal-fired power plants include mercury, sulfur oxides, and nitrogen oxides. Mercury reaches humans when they eat fish contaminated by airborne mercury that settles in lakes and streams. Scientific data have not yet determined a significant link between mercury that originates from coal-fired power plants and significant health effects in humans. However, sulfur oxides and nitrogen oxides contribute to air pollution, which can cause upper respiratory conditions (see Table 4.3.)

Coal miners are at risk for developing pneumoconiosis (black lung disease), which results from chronic inhalation of coal dust. This risk has been drastically reduced, however, by using personal protective equipment such as dust masks and respirators, covering the walls of tunnels and shafts with pulverized white rock to lower the level of the dust, and spraying water to promote settling of the dust.

Solutions

the clean coal technology law. In 1984 Congress established the DOE's Clean Coal Technology (CCT) program (PL 98–473). Congress directed the DOE to administer cost-shared projects (financed by both industry and government) to demonstrate clean coal technologies. The demonstration projects had the goal of

FIGURE 4.6

TABLE 4.3

using coal in more environmentally and economically efficient ways.

clean coal technology and the clean air act. The stated goal of both Congress and the DOE has been to

FIGURE 4.7

develop cost-effective ways to burn coal more cleanly, both to control acid rain and to improve the nation's energy security by reducing dependence on imported fuels. One strategy is a slow, phased-in approach in which utility companies and states reduce their emissions in stages.

Under the Clean Air Act of 1990 (PL 101–549), restrictions on sulfur dioxide and nitrogen oxide emissions took effect in 1995 and tightened in 2000. Each round of regulation requires coal-burning utilities to find lower-sulfur coal or to install cleaner technology, such as "scrubbers" that reduce smokestack emissions that contribute heavily to air pollution. When the first Clean Air Act was passed in 1970, it was aimed at changing the air-quality standards at new generating stations, and older coal-using plants were exempt. Under the 1990 act, older plants are also covered by the regulations.

In January 2004 the Environmental Protection Agency (EPA) proposed new regulations for reducing emissions of sulfur dioxide, nitrogen oxides, and mercury from coal-burning power plants. The Interstate Air Quality Rule focuses on twenty-nine eastern states whose sulfur dioxide and nitrogen oxide emissions are significantly contributing to fine particle and ozone pollution problems. The Utility Mercury Reductions Rule focuses on controlling mercury emissions from power plants. (When taken into the body, mercury can result in serious health effects in children.) These proposed actions strengthen Clean Air Act regulations and standards but are not specifically mandated by the Congress. When implemented, the EPA expects them to result in rapid and significant air quality improvement.

cleaner coal use. The coal-burning process can be cleaned by physical or chemical methods. Scrubbers, which are a physical method commonly used to reduce sulfur dioxide emissions, filter coal emissions by spraying lime or a calcium compound and water across the emission stream before it leaves the smokestack. The sulfur dioxide bonds to the spray and settles as a mudlike substance that can be pumped out for disposal. Scrubbers, however, are expensive to operate, so particulate collectors are the most common emissions cleaners for coal. While they are cheaper to operate than scrubbers, they are less effective. Cooling towers reduce heat released into the atmosphere and reduce some pollutants. Chemical cleaning, a relatively new technology not yet in widespread use, involves the use of biological or chemical agents to clean emissions.

Under the new environmental regulations of the 1990 Clean Air Act and its amendments, plants with coal-generated boilers must be built to reduce sulfur emissions by 70 to 90%. New, high-sulfur coal electricity plants, designed to meet emission standards, use 30% of their construction costs on pollution control equipment and take up to 5% of their power output to operate this equipment. Research to lower these costs is important because of the quantity of electricity produced with coal in the United States.

The EIA's Annual Energy Review 2003 (2004) notes that in 2002 coal-fired electricity plants that had environmental equipment installed had a production capacity of 329.5 gigawatts (1 gigawatt equals 1,000 megawatts). Of this capacity, 100% was generated within plants using particulate collectors, 47% in those with cooling towers, and 30% in those with scrubbers. (Some plants use more than type of environmental equipment so the figures add up to more than 100%.) The use of scrubbers is projected to increase as new regulations from the 1990 Clean Air Act and its amendments take effect.

COAL EXPORTS

Since 1950 the United States has produced more coal than it has consumed. The excess production has allowed the United States to become a significant exporter of coal to other nations. However, exports of this energy source have declined dramatically since 1991, when the U.S. exported 109 million short tons of coal. In 2003 the U.S. exported 43 million short tons, up from 39.6 million short tons in 2002, the lowest amount exported since 1961. (See Table 4.4.)

In 2003 coal made up 28% of all U.S. energy exports. (See Figure 1.5 in Chapter 1.) Europe received 35% of U.S. coal exports. The individual countries that bought the most U.S. coal were Canada, Brazil, Italy, and the Netherlands. (See Table 4.4.)

INTERNATIONAL COAL USAGE

The Annual Energy Review 2003 (2004) reported that world coal production was 1.1 billion short tons in 2002 and accounted for 21% of world energy production. China led the world in coal production, mining just over 1.5 billion short tons, followed by the United States at 1.1 billion short tons. (See Figure 4.8.) Other major producers were India, Australia, Russia, South Africa, Germany, and Poland.

World consumption of coal in 2002 totaled 5.3 billion short tons. Besides being the largest producer, China was

FIGURE 4.8

TABLE 4.4

FIGURE 4.9

also the largest consumer of coal in 2002, using more than 1.4 billion short tons, followed by the United States at 1.1 billion short tons. (See Figure 4.9.) Other major consumers included India, Germany, Russia, and Japan.

FUTURE TRENDS IN THE COAL INDUSTRY

In Annual Energy Outlook 2004 the EIA forecasted that domestic coal production will increase to almost 1.3 billion short tons by 2015 and increase slightly from there to almost 1.4 billion short tons by 2020 and approximately 1.5 billion short tons by 2025. (See Table 4.5.) Domestic consumption is projected to match production, reaching nearly 1.3 billion short tons in 2015, almost 1.4 billion short tons by 2020, and approximately 1.5 billion short tons by 2025. Electricity generation will still use the majority of coal in 2015 (approximately 1.2 billion short tons), 2020, and 2025. Total coal consumption for electricity generation is expected to increase by an average of 1.8% per year because of high natural gas prices.

Coal prices are projected to decline from $17.90 per short ton in 2002 (see Table 4.5) to a low of $16.19 per short ton in 2016. These price decreases will likely occur because of improvements in mine productivity, a shift to western production, declines in rail transportation costs, and competitive pressures on labor costs. After 2016 prices will likely rise as productivity improvements slow and the industry faces increasing costs to open new mining areas. By 2025 the price of coal is projected to rise to $16.57 per short ton. (See Table 4.5.) Nevertheless, this price is still below the 2002 price.

Environmental concerns about acid rain and global warming may continue to grow. The outlook for the U.S. coal industry could be affected by acid rain legislation, the development of clean coal technologies, and, over the longer term, the problem of global warming. Environmental issues will increasingly become international problems. China, with nearly five times the population of the United States and a growing economy, may surpass the United States in carbon emissions by 2020.

The EIA predicts that U.S. coal exports will decline from 6% in 2002 to less than 3% in 2025. This decline will likely be the result of a decline in the demand for coal in Europe and the Americas. Also, other countries are expected to reduce costs and gain currency exchange advantages against the U.S. dollar.

TABLE 4.5