Coal is divided into four classes: anthracite, bituminous, sub-bituminous, and lignite. Elemental analysis gives empirical formulas such as C137H97O9NS for bituminous coal and C240H90O4NS for high-grade anthracite. Anthracite coal is a dense, hard rock with a jet-black color and a metallic luster.
What is the chemical structure of coal?
As for its chemical composition, coal is a mixture of high-molecular-weight polycyclic aromatic compounds, such as benzene C6H6, toluene C6H5CH3, xylene C6H4(CH3)2, naphthalene C10H8, anthracene C14H10, pyrene C16H10 and their derivatives with high mass fraction of carbon, as well as of water and volatile substances …31 мая 2019 г.
What molecules are in coal?
The organic compounds in coal are composed of the elements carbon, hydrogen, oxygen, nitrogen, sulfur, and trace amounts of a variety of other elements.
What is produced when coal is burned?
But when coal burns, its carbon combines with oxygen in the air and forms carbon dioxide. Carbon dioxide is a colorless, odorless gas, but in the atmosphere, it is one of several gases that can trap the earth’s heat.
What are 4 types of 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.
Why is coal bad for the environment?
The burning of fossil fuels releases greenhouse gases into the atmosphere, increasing levels of CO2 and other gasses, trapping heat, and contributing to global climate change. … Coal-fired power plants release more greenhouse gases per unit of energy produced than any other electricity source (1).
Why Coal is a dirty fuel?
Coal is known for being a dirty fuel, not just because of its high carbon content compared with other fossil fuels but also because it contains a large amount of toxic heavy metals and other chemicals. … Others harmful materials remain as excess waste when the coal is burned.
Is Coal still being formed?
The process of coal formation is still taking place today, says Bailey. “The precursor to coal is called peat, and that is just uncompressed plant matter.” Peat accumulates in wet swampy environments known as mires, and that process is taking place today in areas such as Indonesia and even the Antiplano in the Andes.
What is the formula of coal gas?
Coal gas, gaseous mixture—mainly hydrogen (H2), methane (CH4), and carbon monoxide (CO) — formed by the destructive distillation (i.e., heating in the absence of air) of bituminous coal and used as a fuel. Sometimes steam is added to react with the hot coke, thus increasing the yield of gas.
Why is coal so cheap?
Coal is only considered cheap because coal plants do not have to pay for the full social and environmental costs of coal burning on people’s health, the natural environment, and our climate. … Wind power is now cheaper than coal in many markets; in the United States it’s now half the price of existing coal plants.
What is the scientific name for coal?
Lignite (brown coal) Anthracite (hard coal)
What is Coal made of?
Coal is formed when dead plant matter submerged in swamp environments is subjected to the geological forces of heat and pressure over hundreds of millions of years. Over time, the plant matter transforms from moist, low-carbon peat, to coal, an energy- and carbon-dense black or brownish-black sedimentary rock.
Which is the best quality of coal?
Anthracite: The highest rank of coal. It is a hard, brittle, and black lustrous coal, often referred to as hard coal, containing a high percentage of fixed carbon and a low percentage of volatile matter.
What type of rock is coal?
Coal is a combustible sedimentary rock formed from ancient vegetation which has been consolidated between other rock strata and transformed by the combined effects of microbial action, pressure and heat over a considerable time period. This process is commonly called ‘coalification’.
Is coal heavy or light?
Coal is slightly denser than water (1.0 megagram per cubic metre) and significantly less dense than most rock and mineral matter (e.g., shale has a density of about 2.7 megagrams per cubic metre and pyrite of 5.0 megagrams per cubic metre).