3. 1. Introduction about fuel
2. Over all about solid fuel
3. Types of solid fuel and characteristics
4. Formation of solid fuels
5. Advantages and disadvantage of solid fuels
6. Conclusion
1. INTRODUCTION
DEBREMARKOS UNIVERSITY
INSTITUTE OF TECHNOLOGY
MECHANICAL ENGINEERING DEPARTMENT
1
This project
includes:-
5. 1.What is fuel?
5
Fuel it is any artificial or naturally occurring
substances which often burning /react with
oxygen/ release a large amount of energy which
can be used for domestic and industrial process.
Where do we get
energy from? We get
energy from the food we eat. A
substance that produces energy
on burning is called a fuel. Hence
, food can be thought of as a fuel
for our body.
6. Types of fuels
6
Fuels are available in solid , liquid or
gaseous form.
Wood , coal , coke and cow dung cakes are
some examples of solid fuels.
Liquefied Petroleum Gas (LPG), Compressed
Natural Gas (CNG) and biogas are examples
of gaseous fuels. Kerosene, petrol and diesel
are examples of liquid fuels.
Natural gas, biogas, syngas are example of
liquid fuels.
7. 2. Solid fuels
7
Solid fuel refers to various forms of solid material that can be burnt
to release energy, providing heat and light through the process of
combustion.
Solid fuels can be contrasted with liquid fuels and gaseous fuels.
Common examples of solid fuels include wood, charcoal, peat, coal,
Hexamine fuel tablets, wood pellets, corn, wheat, rye and other
grains.
Solidfuels are extensively usedin rocketry as solid propellants.
Solid fuels have been used throughout human history to create fire
and solid fuel is still in widespread use throughout the world in the
present day.
8. 3. Classification of solid fuels
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Solid fuels are mainly classified into two categories,
1.Natural fuel : naturally occurred
Example -wood, coal, etc. and
2. Manufactured fuels: manufactured by human
being/human made/
Example: charcoal, coke, briquettes, etc.
9. Characteristics of solid fuels
9
Some types of solid fuels
1. Wood
2. Biomass
3. Peat
4. Coal
5. Coke
6. Municipal waste
7. Fossil fuels
10. 1. Woods and their Characteristics
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The most commonly used and easily obtainable solid fuel is wood.
It is the oldest type of fuel which man had used for centuries after the
discovery of the fire itself.
Wood fuel can refer to several fuels such as firewood, charcoal, wood
chips sheets, pellets, and sawdust.
The particular form used depends upon factors such as source,
quantity, quality and application.
In many areas, wood is the most easily available form of fuel,
requiring no tools in the case of picking up dead wood, or few tools.
Today, burning of wood is the largest use of energy derived from a
solid fuel biomass.
Wood fuel can be used for cooking and heating, and occasionally for
fueling steam engines and steam turbines that generate electricity.
11. Constituents of Wood
11
Wood is vegetable tissue of trees and bushes.
It consists of mainly cellular tissue and lignin and
lesser parts of fat and tar, as well as sugar.
The main constituents of several kinds of wood are
given in Table
Table1: constituent of wood (%)
12. Average value of constituentsof wood(%)
12
Table2: average constituent of wood(%)
13. Ash
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The ash content of wood is negligible.
The ash consists of mineral water that is found in the wood itself,
with an admixture of some impurities which occur during
transportation, etc.
The mineral matter is distributed in the tree rather irregularly.
The ash consists of mainly potassium carbonate with varying degrees
of calcium, magnesium and sodium carbonate, as well as minute
quantities of iron oxides, alumina and silica.
Pure ash is white in color.
14. Coals and their Characteristics
14
Coal is a combustible black or brownish-black sedimentary rock usually
occurring in rock strata in layers or veins called coal beds or coal seams.
Throughout history, coal has been used as an energy resource, primarily burned
for the production of electricity and heat, and is also used for industrial
purposes, such as refining metals.
Coal is the largest source of energy for the generation of electricity worldwide, as
well as one of the largest worldwide anthropogenic sources of carbon dioxide
releases.
The extraction of coal, its use in energy production and its by products are all
associated with environmental and health effects including climate change.
15. Analysis of Coal
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To ascertain the commercial value of coal
certain tests regarding its burning
properties are performed before it is
commercially marketed. Two commonly
used tests are : Proximate analysis and
Ultimate analysis of coal.
Calorific value of coal is defined as the
quantity of heat given out by burning one
unit weight of coal in a calorimeter.
16. Proximate Analysis of Coal
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This analysis of coal gives good indication about heating and burning
properties of coal.
The test gives the composition of coal in respect of moisture, volatile
matter, ash and fixed carbon. The moisture test is performed by
heating 1 gm of coal sample at 104oC to 110oC for 1 hour in
an oven and finding the loss in weight.
The volatile matter is determined by heating 1 gm of coal sample in a
covered crucible at 950oC for 7 minutes and determining loss in
weight, from which the moisture content as found from moisture test
is deducted. Ash content is found by completely burning
the sample of coal in a muffled furnace at 700oC to 750oC and
weighing the residue.
17. 17
The results of proximate analysis of most coals indicate the
following broad ranges of various constituents by weight :
The importance of volatile matter in coal is due to the fact that
it largely
governs the combustion which in turn governs the design of grate
and
combustions space used. High volatile matter is desirable in gas
making,
while low volatile matter for manufacturing of metallurgical coke.
18. .
The Ultimate Analysis of Coal
18
This analysis of coal is more precise way to find the chemical composition
of coal with respect to the elements like carbon, hydrogen, oxygen, nitrogen,
Sulphur and ash. Sine the content of carbon and hydrogen that is already
combined with oxygen to form carbon dioxide and water is of no value for
combustion, the chemical analysis of coal alone is not enough to predict the
suitability of coal for purpose of heating. However, the chemical composition
is very useful in combustion calculations and in finding the composition of
flue gas.
20. 20
Peat, considered to be a precursor of coal, has industrial importance as a
fuel in some regions, for example, Ireland and Finland.
Lignite, also referred to as brown coal, is the lowest rank of coal and used
almost exclusively as fuel for electric power generation.
Sub-bituminous coal, whose properties range from those of lignite to
those of bituminous coal and are used primarily as fuel for steam-
electric power generation.
Bituminous coal, dense mineral, black but sometimes dark brown, used
primarily as fuel in steam-electric power generation, with substantial
quantities also used for heat and power applications in manufacturing
and to make coke.
Anthracite, the highest rank; a harder, glossy, black coal used
primarily for residential and commercial space heating.
21. 21
The broad range in which the constituents of coal
vary by weight as determined by ultimate analysis
are given below :
22. ManufacturedSolid Fuels and their Characteristics:
22
The manufactured solid fuels include, charcoal, coke,
briquettes, etc. They are obtained from the natural fuels, like
wood, coal, etc.
Charcoal and its Characteristics
Out of the mentioned various manufactured fuels, the charcoal
occupies the first place. In some parts of the country, for example,
Mysore, huge quantities
of charcoal are being used till today in blast furnaces for reducing
iron ores, etc.
and in many homes charcoal is used for cooking purposes.
Charcoal is a produce derived from destructive distillation of
wood, being left in the shape of solid residue.
Charcoal burns rapidly with a clear flame, producing no smoke
and developing heat of about 6,050 cal/kg.
23. Coke andits Characteristics
23
Coke is a fuel with few impurities and high carbon content, usually made from coal.
It is the solid carbonaceous material derived from destructive distillation of low-ash, low-
sulfur bituminous coal.
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 Coker units or other cracking processes.
It is obtained from destructive distillation of coal, being left in the shape of solid residue.
Coke can be classified into two categories : softcokeand hardcoke.
Soft coke is obtained as the solid residue from the destructive distillation of coal in the
temperature range of 600-650oC. It contains 5 to 10% volatile matter. It burns without
smoke. It is extensively used as domestic fuel.
Hard coke is obtained as solid residue from the destructive distillation of coal in the
temperature range of 1200-1400oC. It burns with smoke and is a useful fuel for metallurgical
process.
25. Advantages and disadvantages of solid fuels
25
Advantages
(a) They are easy to transport.
(b) They are convenient to store without any risk of spontaneous explosion.
(c) Their cost of production is low.
(d) They posses moderate ignition temperature.
Disadvantages
(a) Their ash content is high.
(b) Their large proportion of heat is wasted.
(c) They burn with clinker formation.
(d) Their combustion operation cannot be controlled easily.
(e) Their cost of handling is high.
