Mineral coal - class-IX

There are four different types of coal

Peat is the first stage in the formation of coal. The heat and pressure from the top layers convert dead plants into a spongy brown material called peat.

High grade (HG) and ultra high grade (UHG) anthracite are the highest grades of anthracite coal. 

They are the purest forms of coal, having the highest degree of coalification, the highest carbon count and energy content and the fewest impurities (moisture, ash and volatiles).

Anthracite contains nearly 95% of carbon and is the purest form of coal so anthracite is the purest form of coal than any other forms.

Therefore, option B is correct.

Anthracite coal has highest amount of carbon and has clean burning properties. So, it is used as a household coal.

For a process to be spontaneous at all temperatures, the Gibbs free energy change (delta G = delta H - T*delta S) must be negative. This occurs when delta H is negative (exothermic) and delta S is positive (increase in entropy).

Anthracite has the highest percentage of carbon. Anthracite is the most metamorphosed type of coal (but still represents low-grade metamorphism), in which the carbon content is between 92.1% and 98%.

Bituminous coal is a dense sedimentary rock, usually black which is used primarily as household coal ,fuel in steam-electric power generation and to produce coke.

Peat found in the lowest depth of earth considering the other forms of coal.It also has the lowest percentage of carbon as compared to other forms.In other words, we can say that they are the youngest fossils.

Percentage of carbon present in an air dried sample of anthracite is 94-98%.

Bituminous or black coal is a soft coal containing a tarlike substance called bitumen. It is of higher quality than lignite coal and has low ash content so it is used as coal fuel in homes.

The order of carbon content is as follows:

Peat is a fuel consisting of spongy material formed by the partial decomposition of organic matter in wetlands such as swamps, bogs, and moors. Peat contains tree cellulose, more than $75$% moisture and less than $60$% carbon.

Coal is mainly found in beds of sedimentary rocks. But metamorphic rocks might sometime contain anthracite coal. But sedimentary rocks is the most important source of coal.

Other than Carbon (the main constituent), all the above mentioned elements are also present in coal.

Coal is available in four forms: Lignite, bituminous, anthracite and sub- bituminous. Anthracite is the highest ranked coal with the carbon
percentage of above 87%. The carbon conten in lignite is 60-70%.  Tamil nadu is the largest producer of lignite coal.

Coal is available in 4 forms: Lignite, bituminous, anthracite and sub-bituminous. Anthracite is the highest ranked coal with the carbon percentage of above 87%. The carbon content in bituminous is 77-87%, in sub-bituminous is 71-77% and in lignite is 60-70%.  Lignite has the least carbon content and hence highest ash content.

• Peat has the carbon content of about 
• Anthracite has the carbon content of above 87%.

Anthracite coal has several important advantages not only over other forms of coal but over other energy-producing materials in general. Its most important advantage is, of course, the fact that it produces very little pollution or soot, making it a very clean source of heat. Anthracite coal is also very efficient because only a small amount needs to be burnt to produce a large amount of energy. Additionally, there is a large supply of anthracite, over six billion tons in the Appalachian Mountains alone, with more reserves found in the Rocky Mountains and the Andes.

Hence, the correct option is $C$

• Peat has the carbon content of about 40%-55%
• Anthracite has the carbon content of above 87%.

Fly ash is also known as pulverised fuel ash. It is one of the coal combustion products. The pneumatic system is employed for the disposal of fly ash. 

The substance that burns in the presence of oxygen and heat are called
combustible substances whereas that do not burn are non-combustible
substances. Elements such as carbon, hydrogen and sulphur present in the
fuel makes it combustible.

The ash content of Indian coal is 30℅. Initially, in the 1970s it was 28℅. The quality of Indian coal is deteriorating over the years. Compared to other constituents also, ash content is more in Indian coal. 

The ash content of indian coal is 30℅. Initially in 1970s it was 28℅. The quality of Indian coal is deteriorating over the years. However Sulphur content of Indian coal is low about 0.5℅.

Coal is a black coloured sedimentary rock. When coal is grounded or broken into fine particles using a device called powdered coal mill, the resultant coal obtained is called powdered coal or pulverized coal. It is used in cosmetics, for the generation of electricity etc.

The calorific value of the coal depends upon its ash content. Less the
ash content present, more is the calorific value of the fuel i.e. the fuel
which has less ash content produces more energy on burning. Higher the
calorific value, more is the efficiency of the fuel.

Bituminous coal or black coal is a relatively soft coal containing a tarlike substance called bitumen or asphalt. It is of higher quality than lignite coal but of poorer quality than anthracite and has a high heating (Btu) value . Formation is usually the result of high pressure being exerted on lignite. Bituminous coal is an organic sedimentary rock formed by diagenetic and sub metamorphic compression of peat bog material. Its primary constituents are macerals: vitrinite, and liptinite. The carbon content of bituminous coal is around 60–80%; the rest is composed of water, air, hydrogen, and sulfur.

Lignite is brownish-black in color and has a carbon content around 60–70 percent, a high inherent moisture content sometimes as high as 75 percent, and an ash content ranging from 6–19 percent compared with 6–12 percent for bituminous coal. The energy content of lignite ranges from 10 to 20 MJ/kg (9–17 million BTU per short ton) on a moist, mineral-matter-free basis.

Lignite is brownish-black in color and has a carbon content around 60–70 percent, a high inherent moisture content sometimes as high as 75 percent, and an ash content ranging from 6–19 percent compared with 6–12 percent for bituminous coal.

 A brownish-black coal with generally high moisture and ash content, and the lowest carbon content and heating value is lignite.

The process of conversion of lignite to anthracite is called coalification or metamorphism of coal.
Coal is classified on the basis of its rank. The rank of coal denotes its degree of maturity. Vegetable matter, under the action of pressure, heat and anaerobic conditions, gets converted into different stages of coal namely:
Wood → Peat → lignite → sub-bituminous coal → bituminous coal → anthracite.
Peat is the first stage in the formation of coal.

The calorific value of the fuel is also called as the heat value of the fuel. It is defined as the amount of heat released by burning of unit quantity of the fuel. The calorific value is an important characteristic of the fuel. The unit of measurement of the calorific value is the same as the energy.

The rank of coal is based on the degree to which the original plant material has been transformed into carbon.

The rank of coal is based on the amount of the plant converted into carbon.

Geothermal energy.

The mineral coal with given properties is Anthracite.

Carbon is the main constituent of coal. Thus, coal is considered as an organic compound.

It has been seen that the deeper the coal found, the better quality it is. Because, the deeper we go, the temperature and pressure increases much and hence the quality of coal also increases.

Coal is mainly made up of carbon.Thus, the conversion of dead vegetation into coal is termed as carbonization.

Quinoline is basic compound present in coal tar. Other basic compound present in coal tar is pyridine. 

The main constituent of coal is $carbon$,

Under favorable conditions of high temperature and pressure, dead plants get slowly converted to coal.

In Gujarat, near Thangadh in Saurashtra district, sulphur-containing mineral coal deposits are present.

In Roman Britain, the Romans were exploiting all major coalfields by the late 2nd century AD. While much of its use remained local, a lively trade developed along the North Sea coast. This also extended to the continental Rhineland, where bituminous coal was already used for the smelting of iron ore. After the Romans left Britain, in AD 410, there are few records of coal being used in the country until the end of the 12th century.

Coal is a sedimentary rock formed from plants that died millions of years ago.

Coal, natural gas and petrolium are examples of natural resources which are found as fossils beneath the surface of earth and act as sources of fuel.

Peat is considered as the precursor of coal. Peat is used industrially sometimes for the purpose of fuel.

High temperature and high pressure are required for the formation of coal. When dead vegetation got buried under the soil, they were compressed under the deposited soil. Carbon got trapped in them. High temperature and pressure then converts these dead vegetation to coal.

Coal is obtained from dead vegetation or dead natural forests. The forests got buried under the soil, and then more soil got deposited over them. These forests got compressed under the soil and then carbon got trapped in it. High temperature and pressure convert these dead vegetation to coal.

Anthracite is the best quality of coal.

China tops in the production of coal.

The percentage of free carbon in lignite is 40%.

Coal gas mainly consists of low molecular mass alkanes and alkenes. It is used as a fuel.

The percentage of free carbon in peat is 10-15%.

The percentage of free carbon in bituminous coal is 70%.

The percentage of free carbon in anthracite is 90%. It is the coal of high grade.

Coal is not merely free carbon but it is a complex mixture of several organic compounds with varying amounts of free carbon, depending upon the type of coal.

Coal tar contains a large number of aromatic hydrocarbons which in turn find applications in dyes, drugs, explosives, plastics, etc.

Carbonisation of coal is done to meet the demand coke (required by steel industry as fuel) and coal tar (a rich source of aromatic compounds).

Cresols present in coal tar are acidic in nature. These are weak acids like phenols.

Anthracene present in coal tar is neutral in nature.
Other neutral hydrocarbons include benzene, toluene and naphthalene.

Most coal sent from mine to market travels either by railroad or by barge.  Railroads handle the most coal, which is the largest single commodity carried by the rail industry.  Barges operating along inland waterways and intercoastal and lake routes handle about 20 percent of domestic coal movements.  Railroads and barges combined move nearly two-thirds of all U.S. coal shipments.

Coal has four major markets

Coal is obtained from mines.

• Microfossils are fossils that are generally between 0.001 mm and 1mm size, the study of which requires the use of electron microscopy.
  
• Coal, petroleum and natural gas are called fossil fuels because these were formed from the dead remains of living organisms (fossils).
  
• Paleobotany is the study of fossil plants. 
• Hence the possibility of occurrence of coal in an area,s determined by the study of microfossils (paleobotany).
• So, the correct answer is 'Microfossils'.

The slow process of conversion of dead vegetation into coal is called Carbonization.