Coal is the world’s most abundant fossil fuel, and has long been considered the cheapest for electric power generation. It is used primarily for heating, generating power, and in the the metal processing and industry. Like oil and gas, it can be converted into petrochemicals and even made into gasoline. Coal has traditionally been a key ingredient to make steel. These days it is increasingly being made into “coal-to-liquids” such as synthetic oil and “coal-to-chemicals.”
Coal is plentiful, easy to burn and cheap and fairly evenly distributed around the globe. There is more than 1 trillion tons of recoverable coal, much more than either petroleum or natural gas. It produces energy at a rate of about 5 to 7 cents per kilowatt hour and one pound of it has the potential to brew more than 100 cups of coffee. The main drawbacks with coal are that is dirty, it produces a lot of greenhouse gases, acid rain, air pollution, and the mining of it can scar the landscape.
Like oil and gas, coal is made fossilized and decayed material. Materials that became coal generally ended up in swamps and were peat before they began the long process of converting to coal. The material that became oil were generally put under more pressure. Most coal was produced during the Mississippian and Pennsylvanian geological period that lasted from 300 million years ago to 235 million years ago.
Coal is divided into four categories based on carbon quantity (those with a high amount of carbon are lower quality than with low amounts) 1) lignite (low-grade coal, low in heat and low in sulfur); 2) subitumous coal (very soft, moderate in heat and low in sulfur); 3) bitumous coal (soft, high in heat and high in sulfur); 4) anthracite coal (hard coal, high in heat and low in sulfur). Each type is pressured version of the type listed before it. Bitumous is most abundant and widely used type. Lignite, or brown coal, has a lot of sulfur and give off a bad smell.
Book: “Coal: A Human History” Barbara Reese (Perseus, 2003)
History of Coal
Coal was used by some ancient people for heat and to smelt metals. The Romans made jewelry with it. It wasn't widely used however until the Industrial Revolution, when an abundant, cheap source of energy was needed to keep factories humming and coal-derived coke was needed to produce steel.
The use of coal took off during the Industrial Revolution between in the 18th and 19th centuries. Ironbridge Gorge, west of Birmingham, England is where the industrial revolution began in 1709 when Abraham Darby pioneered a technique of smelting iron ore with coke. The technique made producing iron in large volumes feasible, paving the way for railroads, steamships and heavy industry.
Inventions which made the industrial revolution possible included the Newcome steam pump (1712), adding in cole mining; coal powered steam engines invented by Watt (1769); cheap durable iron machinery produced by the coke-smelting process; and the flying shuttle (1733) and spinning jenny (1764), used to cotton textiles in new large factories. [Source: World Almanac]
Coal is emerging more and more as the energy source of the future as oil and gas supplies dwindle and alternative sources such as solar and wind appear unlikely to take up the slack and nuclear power has too many risks. .
The process of turning coal into liquid fuel was invented by German scientists Franz Fischer and Hans Tropsch in 1923. The Nazis used the technology to fuel their war machine, producing 125,000 barrel a day of synthetic fuel at 25 plants. South Africa uses the same process today. Expensive and environmentally-destructive, coal -derived synthetic fuels emit less sulfur and nitrogen than gasoline when it burned in a car but produce large amounts of carbon dioxide when it made from coal and when it is burned in a car.
Future of Coal
It is tough to figure out exactly what the future holds in store for coal. On one hand demand, particularly from China and India and fast-developing countries in Asia, have outpaced production and driven prices to new highs. But on the other hand many government are anxious to reduce pollution and greenhouse gases by shifting away from coal to cleaner forms of energy.
Many coal producers and government of coal-rich nation believe the increase in energy demand will keep business robust and are making investments to increase production and improve transportation facilities and ports.
Many believe that coal use in the United States is decreasing but in fact the opposite is true. Roughly half the nation’s electricity come from it and Americans consume an average of 20 pounds of it a day. Annual revenues from coal-related industries are more than $260 million a year.
Coal use is expected to rise 55 percent by 2025, largely driven by demand from China and India.
Peabody Energy is the largest coal company in the United States. In recent years it has been expanding globally, investing heavily in mines in Australia in part it take advantage of high profits and low production costs there and high demand in east Asia.
Coal mining has traditionally been associated with oppressive working conditions. In the early Industrial Revolution men broke away coal in underground mines with picks and shovels and children and women carried it to the surface in baskets. As time passed horses, steam engines, elevators, conveyor belts and sophisticated excavating equipment was introduced, but the work remained hard and dangerous. Tens of thousands of miners have died in various kinds of accidents. The pay was low until miner unions became powerful.
Coal mining is very dangerous. Coal miners, particularly those who work underground, routinely face explosions, fires and cave ins. Not surprisingly they are not allowed to enter a mine with anything that will spark. Many miners have survived at least one accident that broke some bones. After years of working in the miners are stricken with black lung, emphysema and bronchitis
Mining with hand-held pneumatic drills, shovels and conveyor belts is hard work. Equipment break downs are common. Some of tunnels are more than 2,500 below the surface
Coals is found in layers called seams. Once it has been extracted coal is easy to store and easy to transport cheaply with railroads, river barges, ships and pipeline slurries. It can be stored outside.
There are two general types of coal mines: 1) surface (strip or open-pit) mines; and 2) underground (or deep) mines.
Surface mining uses explosives, excavators and bulldozers to strip away layers of earth and rock above the coal seams, and uses massive building-size steam shovels to scoop up the coal, and trucks or conveyor belts to take it from the pit.
Mountain top mining is starting to become more common in the United States. In some cases workers blast away 800 to 1,000 feet of rock to expose the seams of coal that lie underneath. The rocky debris is dumped wherever it is convenient. The dust that gets kicked up fouls the air. Explosions that loosen the rock also shake homes. Streams no longer support life or cease to exist.
There are mining operations that can take down entire mountains. They first strip off the first cover and then blast the rocky soil with explosives and dig into the sea, with giant cranes called draglines that can be up to 20 stories high and have scoops large enough to hold several cars. They are so big and powerful that no motor is big enough to power them; they must draw electricity directly from the grid. Valleys are filled with debris or dammed to hold wastewater. A peak may be reduced by as much as 250 feet.
In underground mines, miners descend to coal seams in earth by holes and tunnels called shafts, and use machines to break loose the coal and bring it to the surface. The shafts serve two purposes: to provide an access for miners to the seams and provide a means of getting the coal out of the mine. Sometimes ventilation shafts are added to allow fresh air to circulate into the mine and dangerous gases circulate out.
Underground mining today is highly mechanized. Sometimes mechanical rippers tear loose coal from the seam. Other times mobile drilling machines bore 10-foot-deep holes in the seams and tubes of compressed air are inserted to shatter the coal. A mechanical loader scoops up the coal and takes it to shuttle cars or a conveyor belt that carry it to the surface. Explosives are used to make shafts and blast coal loose but are avoided if possible.
Underground mining is very dangerous. Many miners have been killed by accidents, usually explosions caused by the igniting of methane or some other gases, or the collapse of a shaft or tunnels, or loss of oxygen. Miners are injured or killed by machines or falls.
Often the easy-to-mine, high-grade coal is taken early. As time goes on miners have to go deeper into the earth, under more dangerous conditions, to extract poorer quality coal from thinner seams. Coal became increasingly expensive to extract and large subsidies are needed to keep the coal industry going.
Many coal miners are from families of miners. One miner in the Ukraine told National Geographic, "My father and grandfather were coal miners. We're a dynasty.” A foreman said, "Eighty percent of our workers are from mining families. It seems we Slavs like to do dangerous thing."
Mining — done with hand-held pneumatic drills, shovels and conveyor belts — is hard work. Equipment break downs are common. Some of tunnels are more than 2,500 feet below the surface. Describing his experience in a Donbass mine in the Ukraine, Mike Edwards wrote in National Geographic, "In an elevator we dropped like rocks, 2,200 feet down. Soon Mr. Nikitin wriggled into shaft H-10, barely four feet high...We duck-walked for half a mile...Ahead, presently, other helmet lamps shone, and we saw eyes gleaming in grimy faces. Viktor, Anatoly, and Roman were preparing to start up the big cutting wheel that slices off anthracite."
Coal miners generally work six-hour shifts and are covered head to toe in black grime before ending their work day with a hot shower. Miners face explosions, fires and cave ins. Not surprisingly they are not allowed to enter a mine with anything that will spark. The fatality rate in some underground mines — especially in China — are high. Many miners have experienced at least one accident that broke some bones. After years of working in the mines many miners come down with black lung, emphysema and bronchitis.
Coal Miners in China
Miners generally make around $172 a month but sometimes earn as little as $70 a month. They have little labor representation, health benefits or legal protection. If they get injured they have to pay for their treatment out of their own pockets. If they die their families receive little compensation.
Miners in state-owned mines typically leave for work at 3:00am and return home at 5:00pm covered in a layer of black grit. Days off are few and far between, sometimes only twice a month, even at legal mines. “I really feel like were are slaves,” one miner told is the Washington Post.
Many miners work six or seven days a week in eight-hour shifts, with no break for meals. Each is paid according to how many carts he fills. After room and board and other expenses are subtracted the miners can save or send home the equivalent of a few dollars a month.
Coal miners often earn so little they scavenge hill-size slap heaps for usable chunks of coal to heat their own homes, eat meat only twice a year and subsist on a diet of cabbage, corn gruel and potatoes. They often work in mines owned by owners who live in villas and drive in new black Audis.
Despite the poor working conditions and low pay, many Chinese are anxious to do the work because they have few other ways of making money. Many miners plan to work for several years and save enough to buy some more land or animals. Most miners are migrants. Many are impoverished farmers or laid off workers from distant provinces who are desperate for work. Often several family members work in the same mine.
Mine owners in Shanxi are notorious for their greed and flashiness. Newspapers keep track of how many Hummers, Ferraris and Rolls-Royces they drive and how many luxury condominiums in Beijing and Shanghai they possess. Their wealth is especially obvious because they operate in some of China’s poorest provinces. Many mines are operated by relatives of government officials.
Coal Miners at Work in China
Miners typically wear a yellow safety helmet and a miners lamp and have coal dust imbedded in their forehead lines and dust in their ears. Some work in tunnels that are so low they have to crouch when working and crawl or duck walk when moving through the tunnels. Some wear what amounts to loincloths because the mines are so hot and drag buckets of coal that weigh as much as the miners through the shafts by hand. The only light comes from lamps on the miner’s head. In some cases the lamps are nothing more than candles, whose flames are extremely dangerous when gas fumes are present.
Describing work done at an unlicenced mine near Datong, Erik Eckholm wrote in the New York Times, "Men wearing head lamps climb down crude shafts, where they use picks and crowbars to pry loose chunks of coal...With shovels and by hand, they heap the coal onto metal carts that are jerked through long corridors to open air. Finally is loaded onto trucks for eventual sale throughout China and abroad."
Describing a coal miner at worker in a mine around Pingdingshan on Henan Province, Jane MacCartney wrote in the Times of London, “Mr. Zang...climbs into a metal pulley lift and starts a 100m journey down ...Water drips down the walls. The only light is from a lamp on his plastic helmet. Mr. Zang, wearing rubber boots and a blue cotton jumpsuit, makes his way under the logs and branches that support the tunnel. He follows the narrow rail track for the coal cars, ducking his head to avoid a broken support or dip in the ceiling.”
“The wine of drills at the coal-face grows louder. But first Mr. Zang has to stop to help two other miners as they use brute force and a log to a lever a derailed coal truck back on the track....On the surface, a miner heaves a truck off the pulley lift, pushes it by hand along the rails and empties its load down the side of a coal heap. A bulldozer and two men with shovels then fill a lorry that will take the coal for processing.” The documentary Yuam Shan (“Distant Mountain”) by film maker Hu Jie in the 1990s showed the horrid conditions that miners worker under.
Much of the world’s electricity is produced by coal-fired generators. In a typical coal power plant, the coal is brought in by train or ship, and pulverized and fed into a boiler and superheated. The steam from the boiler powers a generator, or turbine, which is connected to a transformer that transform the energy into electricity that is then carried by power lines to homes, factories and office buildings.
The largest power plants have 180-foot-high boilers that consume 25 tons of coal a minute and push thousand-degree steam through turbines and up 600-foot-high stacks, producing 3,000 megawatts of power, 50 percent more than Hoover Dam, and devouring three 100-car train loads of coal a day for the plant’s 60 year lifespan.
The coal industry is dying out in many places but being reborn in others. Western Europe cut coal use by 36 percent between 1990 and 2005. The United States, China and India have plans to build many more coal-fired power plants.
Coal and the Environment
The main problem with burning coal especially in coal-fired power plants is that it releases large amounts of nitrogen oxides, particulates, sulfur dioxide, carbon dioxide, lead, sulfur and mercury into the atmosphere. The nitrogen oxides are created by heat from the plant which causes nitrogen in the air to fuse with oxygen and become nitrogen oxide. Coals mining results in chopped down mountains, scarred landscapes and it pollutes rivers and lakes and groundwater.
Emissions of air pollution are much lower with new clean plants that use low-sulfur coals and have special burners and catalytic converters that reduce nitrogen oxides; electrostatic precipitators and baghouses that reduce particulates and scrubbers that reduce sulfur oxides. The new plants however require large amounts of water for cooling and generate millions of tons of coal ash laden arsenic, cadmium, lead, mercury, sulfur dioxide and soot. Pollution caused by increased use by these plants to generate more electricity sometimes outweighs the pollution savings offered by their technology.
As oil prices rise more people are likely to turn to coal.
Coal and Global Warming
Coal is one of the largest sources of global-warming-producing, greenhouse gases. Coal produces more carbon dioxide per unit than any other fossil fuel. Carbon dioxide emitted per kilowatt hour: 1) coal, 2.1; 2) petroleum, 1.4; 3) natural gas, 0.8. About a quarter of the world’s carbon dioxide emissions come from coal-burning power plants. All the use of coal together account for about 40 percent of carbon dioxide emissions. If new power plants are built the situation will get worse.
The new modern plants also still release millions of tons of carbon dioxide, as much as 11 million tons a year, only slightly less than similar sized plant built 30 years ago. Almost all the carbon dioxide is released in the atmosphere. There is no easy method to capture carbon dioxide and dispose of it.
The World Bank has issued warning about the consequences of global warming and said the world must wean itself off fossil fuel but at the same time is funding new coal-fired plans in the developing countries such as India, South Africa and Botswana. Marianne Fay, the bank’s chief economist told the Times of London, “There are a lot poor countries which have coal reserves, and for them it’s the only option. Our policy is to continue finding coal to the extent that there no alternative and to push for the most efficient coal plants possible Frankly, ut would be immoral at this stage to say, “We want to have clean hands, therefore we are not going to touch coal.”
Coal gasification, known by the complicated name of integrated gasification combined cycle, or IGCC, is seen by many as the way of the future. Instead of burning coal as is done conventional coal-fired plants the IGCC cooks off impurities as it converts the coal into synthetic gas, which is then burned to generate electricity. The gas burn nearly as cleanly as natural gas; the plants are 10 percent more efficient than conventional coal plants; consumes almost 40 percent less water; and produces less solid waste. It is also much easer to remove carbon dioxide from the coal because it is isolated and concentrated and thus easier to put in the ground or the sea or dispose of in another way.
Coal gasification plants resemble oil refineries. They mix coal or petroleum coke, the coal-like residue from oil refineries, with water and pure oxygen and pumps them in a tall tank, where the mixture is turned into a flammable gas called syngas and pollutants are removed. The syngas is burned in a gas turbine to make electricity. The whole process is very clean and more efficient in reducing pollutants than using scrubbers and catalytic converters. Carbon dioxide is removed and ideally pumped underground. The problem with the technology is that it is less reliable and 20 percent more expensive than conventional plants. On a handful of IGCC plants are earmarked for construction. The big coal companies in the United States claim they are simply too expensive and they need a lot of investment and a long lead time to build.
Scientist at Pennsylvania State University have developed a jet fuel made from a mixture of coal derivatives and petroleum. It is especially advantageous in military aircraft which have hot-burning engines.
Coal-to-liquid technology has a long history. The was invented by German scientists Franz Fischer and Hans Tropsch in 1923. The Nazis used the technology to fuel their war machine, producing 125,000 barrel a day of synthetic fuel at 25 plants. The method was enhanced by apartheid-era South Africa to get around fuel embargoes. Japan, the U.S and several other nations also launched small-scale trials after the oil price shock of the early 1970s. Most experiments were abandoned due to environmental and cost concerns. Coal -derived synthetic fuels emit less sulfur and nitrogen than gasoline when it burned in a car but produce large amounts of carbon dioxide when it made from coal and when it is burned in a car.
Coal tar is a byproduct of turning coal into coke. It is sometimes used in treatments for skin ailments but prolonged exposure to it is linked to increased risks of certain cancers.”
Clean Coal Power Plant
The world first zero-emissions, coal-fired power station opened in Spremberg, eastern Germany in September 2009. It produces affordable electricity without polluting the atmosphere by burring its greenhouse gases and toxic emissions deep the ground, Built by the Swedish firm Vattenfall, the plant is an example of carbon capture and strange (CCS) technology deigned to separate carbon dioxide from other chemicals during the process of generating electricity and remove it and deposit it places where it can be stored indefinitely.
The plans works like this: 1) To burn as clean as possible coal is combusted in almost pure oxygen, concentrating carbon dioxide the flue gas. 2) heat generated in a boiler from he process produces steam that is fed into a turbine to produce electricity. 3) The flue gas is then cleaned of residuals such as ash particles and sulfur. 4) After that flue gas is cooled to condense and remove water, leaving almost pure carbon dioxide, which is then compressed. 5) The compressed carbon dioxide is pumped into an underground reservoir beneath an impermeable rock more than a kilometer below the surface.
The International Energy Authority has predicted that carbon capture and storage could account for almost a third of the carbon dioxide reductions needed by 2050. Most scenario call for the carbon dioxide to be trapped underground for millions of years. Carbon dioxide dissolves into saline water and might eventually turn into sold mineral carbonates.
System for separating carbon dioxide from the exhaust of a power plant can use up to one third of the energy produced by the power plant. Scrubbers must be installed, pipelines have to be built and carbon dioxide levels in the ground must be carefully monitored.
Coal Producers and Users
There is more than a trillion tons of readily available coal. About a quarter of it is in the United States. Global consumption is currently about five billion tons a year. Consumption is expected to rise by 56 percent in the next 20 years. But at these rates there is enough coal to supply energy for the next several hundred years.
Coal prices reached $60.70 a ton in 2005. One of the biggest influences on prices in Asia is demand from China and inability of Australia to keep up with supply. The price of coal rose from $40.90 a ton in march 2007 to $84.30 in March 2008. In Newcastle Australia, the world’s largest export terminal 64 ships waited in a lines with the average wait 25 days.
Recoverable coal deposits (tons in 2006, percent of global reserves): 1) the United States (268 billion, 27 percent); 2) Russia (173 billion, 17 percent); 3) China (126 billion, 13 percent ); 4) India (102 billion, 10 percent); 5) Australia (87 billion, 9 percent ); 6) Europe (66 billion, 6 percent); 7) South Africa (54 billion, 5 percent); 8) Ukraine (38 billion, 4 percent ); 9) Kazakhstan (34 billion, 3 percent); 10) South America (22 billion, 2 percent). [Source: Energy Information Administration, Department of Energy]
Coal production and consumption: (production and consumption tons in 2006): 1) China (2,621 million and 2,578 million) ; 2) the United States (1, 161 million and 1,114 million ); 3) India (497 million and 542 million ); 4) Australia (420 million and 156 million); 5) Russia (341 million and 264 million); 6) South Africa (269 million and 195 million); 7) Germany (223 million and 272 million); 8) Indonesia (186 million and 44 million); 9) Poland (171 million and 155 million); 10) Kazakhstan (106 million and 79 million). [Source: Energy Information Administration, Department of Energy]
In the mid 2000s, the United States consumed about 1 billion tons of coal in the mid 2000s. That works out to about 10 kilograms per person per day. The United States still gets half of its electricity from coal. Japan (198 million tons) and South Korea (98 million tons) are the largest coal importers.
Expected coal consumption in 2025 (millions of tons): 1) China (3,242); 2) United States (1,505); 3) Europe (853); 4) India (736); 5) Russia (288). Other (1,602).
Top 10 coal producers (billions of tons per years): 1) China (1,086); 2) USA (823); 3) former USSR (409); 4) India (222); 5) South Africa (177); 6) Australia (168); 7) Poland (141); 8) UK (96); 9) Germany (73); 10) North Korea.
Coal consumption (millions of tons): 1) China (1,531); 2) Europe (1,117); 3) United States (1,094); 4) India (431); 5) Russia (251). Other (1,016).
Text Sources: World Almanac, United States Geological Survey (USGS) Minerals Resources Program, Investopedia Industry Handbooks, U.S. Energy Information Administration, Department of Energy and National Geographic articles. Also the New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Natural History magazine, Discover magazine, Times of London, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications.
Last updated March 2011