2. 2
Introduction
• Solar energy is converted to chemical energy
through photo-synthesis in plants
• Sun’s Energy stored in plants is released by
burning wood or fossil fuels
• Fossil fuels: coal, oil and natural gas
The Formation of Fuels
3. Introduction
• Solid fuels are combustibles, ranging from
wood, peat and lignite, through refuse and
other low calorific value substances, to coal
and other solid fuels derived from it.
• Coal represents by far the largest component
of the world’s fossil fuel reserves.
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4. Introduction
• Coal was the fuel which fired the Industrial
Revolution, but it is no longer the cheapest
option among the fossil fuels.
• The cost of working the deposits and the
investment in technology needed to meet
increasingly stringent emissions standards
have increased the cost of burning coal.
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5. Coal
Coal is a readily combustible black or brownish-black
rock.
Coal is a fossil fuel formed in swamp ecosystems
where plant remains were saved by water and mud
from oxidization and biodegradation.
It is composed primarily of carbon along with
assorted other elements, including sulphur.
en.wikipedia.org/wiki/Coal
6. Coal
It is a sedimentary rock, but the harder forms, such
as anthracite coal, can be regarded as metamorphic
rocks because of later exposure to elevated
temperature and pressure.
It is the largest single source of fuel for the
generation of electricity world-wide, as well as the
largest world-wide source of carbon dioxide
emissions, slightly ahead of petroleum and about
double that of natural gas.
Coal is extracted from the ground by coal mining,
either underground mining or open pit mining
(surface mining).
en.wikipedia.org/wiki/Coal
7. • Coal is a sedimentary rock of vegetable origin.
Vast deposits of plant material, formed
approximately 80 million years ago, were
consolidated by pressure, heat and earth
movement.
• The rank of a coal is related to its geological
age and, generally, its depth in the earth.
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Coal
9. • In thermal terms 90% of the known
hydrocarbon fuel deposits are formed by coal.
• The carbon: hydrogen ratio of coal is the
highest of the fossil fuels, hence the calorific
values of coals are principally determined by
the carbon in the fuel.
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Coal
10. • It is usual to consider coals in terms of their
rank: in general, a high ranking coal will have a
high carbon content.
• The other major coal constituent element,
hydrogen, is present in hydrocarbons which
are released as volatile matter when the coal
is heated.
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Coal
11. Coal
• The ranking sequence is:
Wood
Peat
Lignite (brown coal)
Bituminous Coal
Anthracite
• In general, deposits close to the surface which
can be worked by strip mining produce a more
economical fuel than deep mined coal.
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12. Types of Coal Found
Bituminous coal is a relatively hard and less
sulfurous coal containing a tar-like substance
called bitumen and would be burnt largely on
domestic fires after being turned into coke fuel.
Sub-bituminous coal is a coal whose properties
range from those of lignite to those of bituminous
coal and is used primarily as fuel for steam-electric
power generation. It is set to fuel power stations
and cement works in Pakistan.
Lignite is a low-grade, sulfurous coal that is
generally used in modified industrial furnaces to
generate heat for boilers, coke oven heaters, brick
kilns, etc.
en.wikipedia.org/wiki/Fuel_extraction_in_Pakistan
15. Introduction
• Recent developments in gasification processes
have shown that it is possible to produce gas
from coal at a viable thermal efficiency and to
remove the sulfur from the fuel at the same
time.
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16. 2. Coal Classification
• As the rank of a coal increases, its carbon
content increases from 75% to about 93% (by
weight), the hydrogen content decreases from
6% to 3%, and the oxygen content decreases
from 20% to 3%.
• A useful method for analyzing a coal is the
proximate process.
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17. Coal Reserves in Pakistan
Coal -the black gold, is found in all the four provinces
of Pakistan. Country has huge coal resources, about
185 billion tons, out of which 3.3 billion tons are in
proven/measured category and about 11 billions are
indicated reserves, the bulk of which is found in Sindh
province.
The current total mine-able reserves of coal are
estimated at 2 billion tones (60 % of the measured
reserves).
www.gsp.gov.pk/
21. Moisture in coal
• The moisture in coal is made up of two
components: surface moisture and inherent
moisture.
• The former is affected by the way in which the
coal is stored, and is thus variable.
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22. Possible Utilizations of Coal
Domestic Combustion
Commercial Combustion
Combustion for Boilers
Power Production
Blast Furnaces
Adsorption Processes
Carbonization Process
Gasification Process
Fischer-Tropsch Synthesis
