How does coal originate

Remaining coal reserves are even softer lignite and sub-bituminous. Moisture decreases, rank increases. Rank increases, fixed carbon increases. It is generally accepted that coal originated from plant debris including ferns, trees, bark, leaves, roots and seeds some of which accumulated and settled in swamps.

Coal Origin and Properties. The resulting pressure and heat turned the plants into the substance we call coal. Coal is classified into four main types, or ranks: anthracite, bituminous, subbituminous, and lignite. The ranking depends on the types and amounts of carbon the coal contains and on the amount of heat energy the coal can produce.

The rank of a coal deposit is determined by the amount of pressure and heat that acted on the plants over time. All of the anthracite mines in the United States are in northeastern Pennsylvania.

In the United States, anthracite is mainly used by the metals industry. Bituminous coal in the United States is between million and million years old. Bituminous coal is used to generate electricity and is an important fuel and raw material for making coking coal or use in the iron and steel industry.

Most subbituminous coal in the United States is at least million years old. The remainder was produced in Alaska, Colorado, and New Mexico. Lignite coal deposits tend to be relatively young and were not subjected to extreme heat or pressure. Lignite is crumbly and has high moisture content, which contributes to its low heating value.

Lignite is mostly used to generate electricity. A facility in North Dakota also converts lignite to synthetic natural gas that is sent in natural gas pipelines to consumers in the eastern United States. Coal explained. The rooms are about 9 meters 30 feet wide, and the support pillars can be 30 meters feet wide. There are two types of room-and-pillar mining: conventional and continuous. In conventional mining, explosives and cutting tools are used. In continuous mining, a sophisticated machine called a continuous miner extracts the coal.

In developing countries, room-and-pillar coal mines use the conventional method. Underground Mining: Retreat Mining Retreat mining is a variation of room-and-pillar. When all available coal has been extracted from a room, miners abandon the room, carefully destroy the pillars, and let the ceiling cave in.

Remains of the giant pillars supply even more coal. Retreat mining may be the most dangerous method of mining. A great amount of stress is put on the remaining pillars, and if they are not pulled out in a precise order, they can collapse and trap miners underground.

How We Use Coal People all over the world have been using coal to heat their homes and cook their food for thousands of years. Coal was used in the Roman Empire to heat public baths. In the Aztec Empire, the lustrous rock was used for ornaments as well as fuel. The Industrial Revolution was powered by coal. It was a cheaper alternative than wood fuel, and produced more energy when burned.

Coal provided the steam and power needed to mass-produce items, generate electricity, and fuel steamships and trains that were necessary to transport items for trade. Today, coal continues to be used directly heating and indirectly producing electricity.

Coal is also essential to the steel industry. Fuel Around the world, coal is primarily used to produce heat. Coal can be burned by individual households or in enormous industrial furnace s.

It produces heat for comfort and stability, as well as heating water for sanitation and health. Electricity Coal-fired power plants are one of the most popular ways to produce and distribute electricity.

In coal-fired power plant s, coal is combusted and heats water in enormous boilers. The boiling water creates steam, which turns a turbine and activates a generator to produce electricity.

Poland, China, Australia, and Kazakhstan are other nations that rely on coal for electricity. Coke Coal plays a vital role in the steel industry. In order to produce steel, iron ore must be heated to separate the iron from other minerals in the rock.

In the past, coal itself was used to heat and separate the ore. However, coal releases impurities such as sulfur when it is heated, which can make the resulting metal weak. As early as the 9th century, chemists and engineer s discovered a way to remove these impurities from coal before it was burned.

This drives off impurities such as coal gas, carbon monoxide, methane, tars, and oil. The resulting material—coal with few impurities and high carbon content—is coke. The method is called coking.

The hot air ignites the coke, and the coke melts the iron and separates out the impurities. The resulting material is steel.

Coke provides heat and chemical properties that gives steel the strength and flexibility needed to build bridges, skyscrapers, airports, and cars. Many of the biggest coal producers in the world the United States, China, Russia, India are also among the biggest steel producers. Japan, another leader in the steel industry, does not have significant coal reserves. Synthetic Products The gases that are released during the coking process can be used as a source of power.

Coal gas can be used for heat and light. Coal can also be used to produce syngas , a combination of hydrogen and carbon monoxide. Syngas can be used as a transportation fuel similar to petroleum or diesel. In addition, coal and coke byproducts can be used to make synthetic materials such as tar, fertilizers, and plastics.

Coal and Carbon Emissions Burning coal releases gases and particulate s that are harmful to the environment. Carbon dioxide is the primary emission. It is called a greenhouse gas because it absorbs and retains heat in the atmosphere, and keeps our planet at a livable temperature.

In the natural carbon cycle , carbon and carbon dioxide are constantly cycled between the land, ocean, atmosphere, and all living and decomposing organisms. Carbon is also sequester ed, or stored underground. This keeps the carbon cycle in balance. However, when coal and other fossil fuels are extracted and burned, they release sequestered carbon into the atmosphere, which leads to a build-up of greenhouse gases and adversely affects climate s and ecosystems.

Other Toxic Emissions Sulfur dioxide and nitrogen oxides are also released when coal is burned. These contribute to acid rain , smog , and respiratory illness es.

Mercury is emitted when coal is burned. In the atmosphere, mercury is usually not a hazard. In water, however, mercury transforms into methylmercury, which is toxic and can accumulate in fish and organisms that consume fish, including people.

Fly ash which floats away with other gases during coal combustion and bottom ash which does not float away are also released when coal is combusted. Depending on the composition of the coal, these particulates can contain toxic elements and irritants such as cadmium, silicon dioxide, arsenic, and calcium oxide. Unfortunately, fly ash is often stored in landfills or power plants, and can drain into groundwater.

As a response to this environmental hazard, fly ash is being used as a component of concrete , thereby isolating it from the natural environment. Many countries do not regulate their coal industries as strictly as the U. Coal Fires Under the right conditions of heat, pressure, and ventilation, coal seams can self-ignite and burn underground.

Lightning and wildfires can also ignite an exposed section of the coal seam, and smoldering fire can spread along the seam. Coal fires emit tons of greenhouse gases into the atmosphere. Even if the surface fire is extinguished, the coal can smolder for years before flaring up and potentially starting a wildfire again. Coal fires can also begin in mines as a result of an explosion. Once coal catches fire and begins smoldering, it is extremely difficult to extinguish. Advantages and Disadvantages Advantages Coal is an important part of the world energy budget.

It is relatively inexpensive to locate and extract, and can be found all over the world. Unlike many renewable resources such as solar or wind , coal production is not dependent on the weather. It is a baseload fuel, meaning it can be produced 24 hours a day, 7 days a week, days a year. We use and depend on many things that coal provides, such as heat and electricity to power our homes, schools, hospitals, and industries.

Steel, vital for constructing bridges and other buildings, relies on coke for almost all production. Coal byproducts, such as syngas, can be used to make transportation fuels. Coal mining also provides economic stability for millions of people worldwide. The coal industry relies on people with a wide range of knowledge, skills, and abilities. Jobs associated with coal include geologists, miners, engineers, chemists, geographers, and executives.

Coal is an industry that is critical to countries in both the developed and developing world. Peat itself has long been used as a fuel source in some parts of the world, but it's still a far cry from coal. For that transformation to happen, sediment must eventually cover the peat, Hackley explains, compressing it down into the Earth's crust. That sedimentation can occur in a variety of ways, and it swept over many peat swamps when the Carboniferous Period ended about million years ago.

As continents drifted and climates shifted, the peat was shoved down even deeper, with rock crushing it from above and geothermal heat roasting it from below. Over millions of years, this geological Crock-Pot pressure-cooked peat deposits to create coal beds. While Appalachia's mountainous mines tap into some of the country's oldest, largest and most iconic coal beds, American coal didn't all form at once, Ruppert points out.

The Carboniferous Period, which pre-dated dinosaurs, was peat bogs' heyday, but new coalification continued long into and after the age of the dinosaurs. In fact, the West is now America's top coal-producing region , churning out a steady stream of less mature coals from the Mesozoic and Cenozoic eras. The country's most prolific coal mines are in the Powder River Basin , a subterranean bowl that straddles the Montana-Wyoming state line.

Unlike Carboniferous coals, Ruppert says, younger deposits in the West were mostly formed inside large basins that rose out of shallow seas and gradually slipped back underground. The rainfall was right, the climate was right, and then everything got buried. Coalification is an ongoing process, with many of the coals we currently dig up and burn still considered "immature" by geologic standards. The four main types are listed below, in order of maturity:.

This soft, crumbly and light-colored fossil is the least mature peat product to be considered coal. Some of the youngest lignite still contains visible pieces of bark and other plant matter, although USGS geologist Susan Tewalt says that's rare in the United States.

Lignite is low-grade coal to begin with, containing only about 30 percent carbon since it hasn't experienced the intense heat and pressure that forged stronger types. Lignite makes up about 9 percent of demonstrated U. Slightly harder and darker than lignite, sub-bituminous coal is also more powerful up to 45 percent carbon content and older, usually dating back at least million years. About 37 percent of the United States' demonstrated coal reserves are sub-bituminous, all of which are located west of the Mississippi River.

Wyoming is the country's top producer, but sub-bituminous deposits are scattered throughout the Great Plains and eastern Rocky Mountains.