Coal how does it produce energy

Does the US still use coal? What state uses the most coal? Which Southern state is the largest producer of coal? How many years of gas are left? Where does the US get natural gas? Who produces the most natural gas in the US? Does America has natural gas? Most of the coal burned in US power plants is bituminous or subbituminous coal.

All types of coal also contain sulfur , which, when burned, releases toxic air pollution. Sulfur content is determined by the conditions under which the coal is formed.

Low-sulfur coal deposits develop in freshwater environments; high-sulfur deposits come from brackish swamps or marine-influenced environments [1]. In the United States, the sulfur content of coal varies along geographic lines, with most—though not all— eastern coal containing high levels of sulfur, and western coal containing much less. In , the United States burned roughly million tons of coal, enough to fill a typical railroad car every 4 seconds [3].

The electricity sector accounted for over 90 percent of all coal used in the United States, with the rest burned in industrial and commercial settings. In room and pillar mining , seams of coal are partially mined, leaving large pillars of coal intact to support the overlying layers of rock.

Longwall mining involves cutting long tunnels into a coal seam and removing the extracted coal by conveyor belt. As the miners and the machinery move along the seam, a hydraulic support system temporarily holds the rock ceiling in place.

Today, both room and pillar and longwall mining are performed with very powerful mining machines, which rapidly cut coal from the face of coal seams.

These machines have gradually replaced less productive and more dangerous methods, which require intermittently drilling the coal seam and blasting it with explosives. Strip mining is used when coal seams are located close to the surface.

It relies on very large machinery and requires many fewer workers per unit of coal. First, vegetation and soil are removed from the immediate surface. Once exposed, the underlying coal seam is removed in strips and transported away by conveyor belt or truck. By law, strip mine owners are required to restore and replant affected areas, though successfully reclaimed acreage is relatively low when compared to acres of newly-mined land [8].

While coal mining has long caused environmental damage, the most destructive mining method by far is a relatively new type of surface mining called mountaintop removal , or MTR. Currently practiced in southern West Virginia, southwestern Virginia, and eastern Kentucky, MTR requires stripping all trees from a mountaintop and blasting away the top several hundred feet with explosives.

The resulting debris is then dumped into adjacent valleys, burying streams and severely—and irrevocably—impacting local environments. Mountaintop removal mines leave behind flattened areas with soils so poor they can only support exotic grasses, displacing diverse and ecologically important forested ecosystems. Impacts include ecosystem loss and fragmentation, higher risks of local flooding and runoff, contamination of local groundwater resources, and occasional deadly accidents.

In Central Appalachia alone, coalfields cover 48, square kilometers approximately While coal is currently mined in 25 states, the main sources of US coal are highly concentrated. In , almost 58 percent of all the coal produced in the United States came from just three states—Kentucky, West Virginia, and Wyoming—with each contributing 6, 11, and 40 percent of US coal production, respectively [6].

In , underground mines, most of them in Appalachia, produced million short tons, or 75 percent of US coal. Surface mining has since overtaken underground mining, accounting for 64 percent of production in In , the largest single source of US coal was Wyoming, with most of it coming from the enormous Powder River Basin [6]. This reflects the large-scale operations of surface mines, which require much fewer employees. The Clean Air Act, especially after amendments passed in , drove a shift toward low-sulfur coal as one of the main methods of reducing sulfur dioxide emissions from coal plants.

Since the predominantly subbituminous coal west of the Mississippi emits much less sulfur per unit of energy, this trend favored western surface mines as a dominant source of new coal production. It also increased the use of mountaintop-removal mining in Central Appalachia for the same reasons—a classic example of unintended consequences. Before coal is shipped long distances, it undergoes a process of preparation to lower shipping costs and prepare it for use in power plants.

Preparation generally includes crushing the coal and removing heavy, extraneous non-coal materials. If coal is high in sulfur or other impurities, it is washed with a water or chemical bath, removing up to 40 percent of inorganic sulfur in the coal.

Not all coal is prepared using the same process. High-sulfur coal commonly undergoes washing to meet environmental regulations, while low-sulfur coal is often crushed and resized without being washed. There are over such reservoirs in Appalachia alone, holding hundreds of millions of gallons of mine waste.

Contaminants from these reservoirs can easily leach into surface and groundwater supplies; in extreme cases, the dams holding these reservoirs can fail, flooding local waterways and putting both wildlife and downstream communities at risk. The volume of waste from processing coal can be substantial; 35 — 40 percent of the raw coal going into a typical washing plants was left behind as waste in [11].

Kate M. Feb 19, Explanation: Coal is a type of rock that forms when dead plant matter is compressed over a large period of time.

Feb 21, Explanation: Boilers produce steam at very high temperature and pressure. Related questions What are some examples of carbon sources and carbon sinks? Why are fossil fuels bad?

How do fossil fuels form? Why did the plants and animals that make up fossil fuels not rot away? What plants and animals make up fossil fuels? Which country has the most coal? As of January , the United States has the largest recoverable coal reserves with an estimated billion short tons of coal remaining, according to the U. Learn more: U. What are the types of coal? The four ranks are: Anthracite : The highest rank of coal. It is a hard, brittle, and black lustrous coal, often What is coal?

Coal is a sedimentary deposit composed predominantly of carbon that is readily combustible. Coal is black or brownish-black, and has a composition that including inherent moisture consists of more than 50 percent by weight and more than 70 percent by volume of carbonaceous material.

It is formed from plant remains that have been compacted, Filter Total Items: 2. Year Published: Assessing U. Shaffer, Brian N. View Citation. Shaffer, B. Geological Survey Fact Sheet —, 6 p. Year Published: Coal--a complex natural resource : an overview of factors affecting coal quality and use in the United States Schweinfurth, Stanley P.