1. Power Point Presentation On
Formation, Occurrence, Extraction And Refining Of
Coal And Petroleum.
Submitted By : Satya Patra, VIII B, Roll No. 22

2. Introduction
Coal
Coal is a non-renewable, combustible, hard, black solid substance, consisting
chiefly of carbonised plant matter, found mainly in underground seams and
used as fuel.
Petroleum
Petroleum is a non-renewable, combustible fuel which mainly consists of
hydrocarbons, and is generally found in liquid state under the sea beds.
Fossil fuels
The fuels which were formed by the decomposition of the remains of animal
and plants dead bodies are known as fossil fuels. E.g. Coal and Petroleum.

3. Formation
How coal was formed?
Millions of years ago, the Earth had dense forests in low-lying wetland
areas. Due to natural processes such as flooding, these forests were
buried underneath soil. As more and more soil deposited over them, they
were compressed. The temperature also rose as they sank deeper and
deeper. As the process continued the plant matter was protected from
biodegradation and oxidation, usually by mud or acidic water. This
trapped the carbon that was eventually covered and deeply buried by
sediments. Under high pressure and high temperature, dead vegetation
and in the absence of air the plant matter was slowly converted to coal.
As coal contains mainly carbon, the conversion of dead vegetation into
coal is called carbonization.

4. How petroleum was formed?
Petroleum was formed by the decomposition of tiny plants and animals
buried deep under the sea, millions of years ago. Millions of years ago,
the plants and animals which lived under the sea died. Their bodies sank
deeper and deeper in to the bottom of the sea. Soon they were covered by
sediments like mud and sand. Due to high temperature and pressure,
action of bacteria, and in the absence of air, the dead remains of the
plants and animals were gradually converted into petroleum. That’s why
petroleum is found between to layers of impervious rocks (non-porous
rocks).

5. Millions of years ago the earth
had swamps that were buried
by natural phenomena such
as landslides, flooding,
earthquakes, etc.
These dead remains got covered by
sediments like mud and sand. Under
great pressure, heat, action of
bacteria, absence of air, the dead
remains slowly got converted into coal
and petroleum. The plant remains got
converted into coal whereas the
remains of marine vegetation got
converted into natural gas and
petroleum

6. Occurrence
Occurrence of coal
Coal is found in beds or seams interstratified with shales, clays,
sandstones, or (rarely) limestones. It is usually under laid by an
underclay (a layer of clay containing roots of plants). The coal is removed
by strip (surface) mining or underground mining methods.
Occurrence of petroleum
Petroleum occurs deep under the surface of the earth between two layers
of impervious rocks (non-porous rocks). Petroleum being lighter than
water, floats over water. Petroleum deposits are usually found mixed
with water, salt, silt, and earth particles such as sand, clay, etc..
Petroleum does not occur in all the places of earth. It is found only in
certain places of earth. Natural gas occurs just above the petroleum oil
trapped under the rocks.

7. Extraction
Extraction of coal
Coal is extracted through deep shaft mining in which very deep holes
are made to reach the ore lying at a great beneath the crust. The most
economical method of coal extraction from coal seams depends on the
depth and quality of the seams, and the geology and environmental
factors. Coal mining processes are differentiated by whether they operate
on the surface or underground. Many coals extracted from both surface
and underground mines require washing in a coal preparation plant.
Extraction of petroleum
Geologists use different machines to locate petroleum reservoirs. After
petroleum deposits are found petroleum is extracted by drilling holes
(called oil wells) in the earth’s crust, where the presence of oil has been
predicted by the survey.

8. Refining
Refining of coal [categorization]
Depending on the carbon content coal can be categorized into:
 Anthracite (Highest carbon content, upto 90% carbon content)
 Bituminous
 Lignite
 Peat (lowest carbon content )
Products of coal
Coal, when heated in absence of air, produces a number of useful
products. These are:
 Coal gas
 Coal tar
 Coke

9. Coal gas, coal tar and coke
Coal Gas
 Coal gas is a gaseous fuel which is obtained by the strong heating of coal in
the absence of air during the processing of coal to get coke.
 Coal gas contains a variety of calorific gases including hydrogen, carbon
monoxide, methane and volatile hydrocarbons together with small
quantities of non-calorific gases such as carbon dioxide and nitrogen.
 Coal gas is a flammable gaseous fuel made from coal and supplied to the
user via a piped distribution system.
Coal Tar
 Coal tar is a brown or black liquid of extremely high viscosity. Coal tar is
among the by-products when coal is carbonized to make coke or gasified to
make coal gas. Coal tars are complex and variable mixtures of phenols,
polycyclic aromatic hydrocarbons.

10.  It is a thick, black liquid having an unpleasant smell which is
obtained by heating coal in absence of air.
 Coal tar is not a single compound. Coal tar is a mixture of about 200
carbon compounds (0r organic compounds).
 The useful carbon components present in coal tar include benzene,
toluene, naphthalene, anthracene, phenol, aniline.
 These components are separated through fractional distillation.
 The products of coal tar are used to make synthetic fibres, drugs
(medicines), plastics, etc.
Coke
 Coke is a tough and porous black solid substance.
 Coke is a fuel with few impurities and a high carbon content, usually
made from coal. It is the solid carbonaceous material derived from
destructive distillation of low-ash, low-sulfur coal.

11.  Cokes made from coal are grey, hard, and porous. While coke can be
formed naturally, the commonly used form is man-made. The form
known as petroleum coke, or pet coke, is derived from oil refinery
cooker units or other cracking processes.
 Coke is a better fuel than coal because it produces more heat on
burning of coal. Moreover, coke produces very little smoke on
burning.

13. Refining of petroleum oil (crude oil)
 The crude petroleum oil is a mixture of solid, liquid and gaseous
hydrocarbons. It is unusable in this form. So, petroleum oil is refined.
 The refining of petroleum oil is carried out in an oil refinery.
 The separation of petroleum into different fractions is done by a
process called ‘fractional distillation’.
 The various useful fractions obtained by the refining of petroleum are:
Petroleum gas, Petrol, Kerosene , Diesel, Lubricating oil, Paraffin wax
and Bitumen.

14. * Spelling
mistakes:
Refinery gas,
kerosene.

15. The Various Fractions Of Petroleum And Their Uses
i. Petroleum gas : Petroleum gas is used as a fuel in homes and industry,
sometimes in the form of Liquified Petroleum Gas (LPG).
ii. Petrol: Petrol is used as a fuel in light vehicles such as motorcycles, cars,
etc.
iii. Kerosene: Kerosene is used as a fuel in wick stoves and pressure stoves to
cook food, is also used for lighting purposes.
iv. Diesel: Diesel is used as fuel in heavy motor vehicles such as buses,
tractors, trucks, etc.
v. Lubricating oil: Lubricating oil is used for lubrication in machines and
engines (like car engines).
vi. Paraffin Wax: Paraffin wax is used for making candles, Vaseline,
ointments, etc.
vii. Bitumen: Bitumen is used for road surfacing. It is also used for water-proofing
the roofs of buildings.