COAL

Coal is a combustible black or brownish-black sedimentary rock composed mostly of carbon and hydrocarbons. It is the most abundant fossil fuel produced in the United States who owns ¼ of the world’s coal reserves. Coal is primarily used as a solid fuel to produce electricity (745%) and heat through combustion.

Coal provides 25% of global primary energy needs and generates 40% of the world's electricity. The world in total produced 6.19 billion tons of coal in 2006.

Coal reserves are beds of coal still in the ground waiting to be mined. The United States has the world's largest known coal reserves, about 267.6 billion short tons. This is enough coal to last approximately 236 years at today's level of use.

In the United States, recoverable coal reserves are located in 33 states which make up 95% of our fossil fuel energy reserves (estimated at 267 billion tons).

Top Ten Hard Coal Producers (2006)

Source: World Coal Institute

World Consumption

Coal forms from layers of sediment and soil that have accumulated over peat. Peat is plant material that is decomposing in oxygen poor, hydrated conditions. When peat is buried it is exposed to heat, pressure and bacterial decay from the increasing accumulation of other sediments that causes it to compress and decompose.

Coal miners use machines to remove coal from the ground and benefit from methods that allow them to easily reach most of the coal reserves available due to major improvement in technology. Two methods exist: surface mining (roughly 2/3 of the reserve in the US) or underground mining.

• Surface mining is used to produce most of the coal in the U.S. because it is less expensive than underground mining. Surface mining can be used when the coal is buried less than 200 feet underground. In surface mining, giant machines remove the top-soil and layers of rock to expose large beds of coal. Once the mining is finished, the dirt and rock are returned to the pit, the topsoil is replaced, and the area is replanted. The land can then be used for croplands, wildlife habitats, recreation, or offices or stores.
• Underground mining, sometimes called deep mining, is used when the coal is buried several hundred feet below the surface. Some underground mines are 1,000 feet deep. To remove coal in these underground mines, miners ride elevators down deep mine shafts where they run machines that dig out the coal.

To generate electricity, coal is usually pulverized and burned in a furnace with a boiler. The furnace heat converts boiler water to steam, which is then used to spin turbines which turn generators and create electricity. Upon combustion, coal produces a number of gaseous byproducts, including greenhouse gases such as carbon dioxide, nitrogen oxide, sulfur dioxide, and methane gas. Burning coal also produces emissions, such as sulfur, nitrogen oxide (NOx), and mercury, that can pollute the air and water. Sulfur mixes with oxygen to form sulfur dioxide (SO2), a chemical that can affect trees and water when it combines with moisture to produce acid rain. Emissions of nitrogen oxide help create smog, and also contribute to acid rain. Mercury that is released into the air eventually settles in water. The mercury in the water can build up in fish and shellfish, and can be harmful to animals and people who eat them. Of the fossil fuels, coal burning plants produce the most carbon dioxide per unit of energy generated. Coal and fuel oil combustion emit fly ash particles into the atmosphere, which contribute to air pollution problems.

Regulations

There is an urgent need to adopt a change in technology within the next 15 to 20 years, as the majority of coal fired power plants that are in generation today rely upon technology that is 50-100 years old releasing high level of carbon dioxide emissions responsible for global warming.

“Carbon dioxide emissions from coal-fired electricity generation comprise nearly 80 percent of the total CO2 emissions produced by the generation of electricity in the United States. Coal combustion currently accounts for 36% of total carbon dioxide emissions in the United States. It is also projected that by the year 2027, total carbon dioxide emissions will increase to 21.4 tons per person which equates to an 8% increase from 2007 emissions. Additionally, according to the United Nations statistics division, in 2003 the United States emitted approximately 24.3% of the total world carbon dioxide emission, with a projection of approximately 20% of the world total by the year 2030.

With the forecasted increase in coal use, carbon emissions due to coal will comprise an even larger majority of total emissions by the year 2030. In 1999, carbon dioxide emissions from coal equated to approximately 1.8 million thousand metric tons. Additionally, coal fired generation has the highest CO2 emission rate of the greenhouse gases (2,249 lbs/MWh).

The coal industry has found several ways to reduce sulfur, nitrogen oxides, and other impurities from coal. They have found more effective ways of cleaning coal before it leaves the mine, and coal companies look for low-sulfur coal to mine. Power plants use "scrubbers" to clean sulfur from the smoke before it leaves their smokestacks. In addition, industry and government have cooperated to develop "clean coal technologies" that either remove sulfur and nitrogen oxides from coal, or convert coal to a gas or liquid fuel.

Clean coal technologies helped make it possible for U.S. utilities to meet more stringent Clean Air Act requirements for industries to reduce pollutants released into the air and the water.

The original Clean Coal Technology Program, which began in 1986, focused on commercializing processes that helped reduce sulfur dioxide and nitrogen oxide emissions and demonstrating more efficient and environmentally friendly alternatives to traditional pulverized coal boilers.

New programs in clean coal technology—such as the Clean Coal Power Initiative (CCPI) – are essential for building on the progress of the original Clean Coal Technology Program, finding solutions for reducing trace emissions of mercury; reducing or eliminating carbon dioxide emissions; and increasing fuel efficiencies. The Clean Coal Power Initiative is a cooperative, cost-shared program between the government and industry which will demonstrate advanced coal-based power generation technologies including carbon capture and storage.

The U.S. Department of Energy has announced in 2007, a Presidential initiative to build "FutureGen," a $1 billion project that will lead to the world's first emission-free plant to produce electricity and hydrogen from coal while capturing greenhouse gases.

Additional Sources:

World Coal Institute. The World Coal Institute is a non-governmental, non-profit, independent organization with membership open to coal producers and coal consumers from around the world. The site contains facts on world and regional coal consumption as well as an extensive links to other fossil fuel groups.

International Energy Agency - Clean Coal. This IEA site provides information on efficient coal supply and use and enhances innovation and continued development of coal as a clean source of energy.