analysis of coal
DESCRIPTION
analysis of coalTRANSCRIPT
Analysis of Coal
Presented By,
Momina Noor M12-PG-01
Mahnoor Butt M12-CE-16
Nehal Imtiaz M12-CE-02
Sabahat Tahir M12-CE-12
Solid Fuel
Combustible
Non-Volatile
Volatile
Non-Combustible
MoistureInorganic
Ash
Analysis of Coal
Proximate Analysis
Ultimate Analysis
Proximate Analysis
Proximate Analysis
MoistureVolatile Matter
AshFixed
Carbon
Moisture
Content
Moisture content varies with
such factors as the mine from
which coal was removed, the coal
seam and the extent to which coal
has been exposed to weather.
High moisture content is
undesirable.
Determination Method Of Moisture Content
A weighed sample of -72 B.S is dried at a temperature of 104
to 110β in an inert atmosphere to constant weight. Atmosphere must be free from oxygen otherwise oxygen will
combine with the coal.
πππππππ‘πππ ππ ππππ π‘π’ππ =πΏππ π ππ π€πππβπ‘ ππ ππππ
ππππβπ‘ ππ ππππ π‘ππππΓ 100
Effects of Moisture on Coal
Reduce the Calorific Value.
Increases the consumption of Coal.
Lengthens the time of heating.
VolatileMatter
Represents the portion of Coal
which is converted into volatile
products when the coal is heated
in the absence of air.
High Volatile Coals tend to burn
with a long flame and give much
smoke.
For maximum thermal efficiency,
volatile matter must be burned
completely.
Determination Method Of Volatile Matter
Heating a weighed and dried sample of coal in a covered
platinum crucible at 500 to 700β for 7 minutes. A high percentage of volatile matter means that a large proportion
of fuel has burnt as a gas..
πππππππ‘πππ ππ ππππ π‘π’ππ =πΏππ π ππ π€πππβπ‘ ππ ππππ
ππππβπ‘ ππ ππππ π‘ππππΓ 100
Effects of Volatile Matter on Coal
Lower Ignition Temperature.
Lower Calorific Value.
Larger Volume for Combustion
Higher tendency to catch fire.
Ash
Coal ash is derived from clay, iron
pyrites, limestone, sand and other
mineral matter.
Ash is an inert material which
consumes heat and the disposal of
which represents an expense to
consumer.
Lower the proportion of ash, greater
the value of coal.
Determination Method Of Ash Matter
Heating the residue left after removal of volatile matter at 600 to 700β for half an hour without covering.
Measured ash value and original mineral matter is related as:πππππππ πππ‘π‘ππ = 1.15 Γ π΄π β
πππππππ‘πππ ππ πππππ‘πππ πππ‘π‘ππ =πΏππ π ππ π€πππβπ‘ ππ ππππ
ππππβπ‘ ππ ππππ π‘ππππΓ 100
Effects of Ash on Coal
Hard and Strong Coal.
Lower Calorific Value.
Produce more slag.
Forms an insulating layer for small values
Can be reduced by washing.
Fixed
Carbon
It is the pure carbon
present in coal.
Determination Method Of Fixed Carbon
Carbonaceous residue from the volatile matter test. Obtained by subtracting from 100 the sum of percentages of
volatile matter, moisture and ash content of coal.
πΉππ₯ππ πΆπππππ = 100 β (ππππ π‘π’ππ + π£ππππ‘πππ πππ‘π‘ππ + ππ β)
Effects of Fixed Carbon on Coal
Greater the Fixed Carbon, Higher the Calorific
Value.
Advantages of
Proximate Analysis
Relatively Quick.
Easily carried out in
laboratory.
Indication of coalβs
quality and type
Ultimate Analysis
Ultimate Analysis of Coal
Ultimate Analysis provides following data: Elemental Carbon Elemental Hydrogen Elemental Oxygen-usually determined by difference rather than
directly. Elemental Sulphur- both organic and inorganic Elemental Nitrogen-nominally about 1% by weight Heating Value
Advantages of Ultimate
Analysis
Gives information about
elementary constituents
of coal.
Useful in designing of
coal burning equipment
and auxiliaries
Thank You