Coal is composed primarily of carbon along with variable quantities of other elements, chiefly hydrogen, sulphur, oxygen, nitrogen. Ultimate analysis is also known as elemental analysis, it is the method to determine the Carbon,Hydrogen,Nitrogen,Sulphur and Oxygen content present in solid fuel.

1. Ultimate Analysis – Constituents of coal
Fossil Fuel Engineering – ERG 252 (1+1)
S.Vignesh – BTG-12-037

2. Introduction
 A fossil fuel, coal forms when dead plant matter
is converted into peat, which in turn is converted
into lignite, then sub-bituminous coal, then
bituminous coal, and lastly anthracite. This
involves biological and geological processes that
take place over a long period of time. Heat and
pressure acts on it to finally convert into coal.

3. Ultimate Analysis
• Coal is composed primarily of carbon along
with variable quantities of other elements,
chiefly hydrogen, sulphur, oxygen, nitrogen.
• Ultimate analysis is also known as elemental
analysis, it is the method to determine the
Carbon,Hydrogen,Nitrogen,Sulphur and
Oxygen content present in solid fuel.

4. Need For Analysis
• It is essential to understand the properties of
biomass materials to evaluate their utility
• As chemical feedstock's and also design suitable
gasifies systems. The analysis is carried out to
find the oxygen required for combustion for
efficient production of energy.
• Two types-proximate and ultimate analysis
• Proximate-it determines moisture content,
volatile matter, ash and fixed carbon content of a
fuel. It is reported as dry weight.

5. Determination of carbon & hydrogen
• About 0.2g of accurately weighed coal is burnt
in oxygen in apparatus shown above.
• CCO2 & HH2O
• KOH & CaCl2 absorb CO2 & H2O respectively.
• Increase in weights of the tubes are noted.

6. % of C:
increase in weight of KOH tube*12*100
weight of the coal sample taken*44
% of H:
Increase in weight of CaCl2 tube*2*100
weight of coal sample taken*18

7. Determination of Nitrogen
• 1g of accurately weighed powdered coal is
heated with conc.H2SO4 in kjeldahl flask.
• It is treated with excess KOH.

8. • Liberated ammonia is distilled over and absorbed in
a known volume of standard solution of acid.
• Unused acid is determined by back titration with
standard NaOH.
% of N is
volume of acid used*normality*1.4
weight of coal sample taken

9. Determination of sulphur
• Sulphur is converted into sulphate.
• The washings are treated with BaCl.
• BaSO4 is precipitated.
• Precipitate is filtered, washed and heated to
constant weight.
• % of S
= weight of BaSO4 obtained*32*100
233*weight of coal sample taken

10. Determination of ash and oxygen
• Coal sample of accurate weight in a crucible is
heated in muffle furnace at 700+50 degree
Celsius for ½ an hour. Crucible is taken out and
cooled first in air and then in desiccators and
weighed.
• % of ash = weight of ash left*100
weight of coal taken
• % of oxygen is
100-percentage of (O+H+S+N+Ash)

11. carbon hydrogen oxygen nitrogen Sulphur
55-60 6-6.5 30-35 1.5-2 0.6-1
Peat

12. Carbon hydrogen Oxygen nitrogen Sulphur
70-73 4.6-5.5 22-26 0.6-1.0 0.6-1.5
Lignite

13. Carbon Hydrogen Oxygen
80 6 15
Bituminous

14. Carbon Hydrogen Oxygen
93 4 3
Anthracite

15. Total carbon
• Fixed carbon+carbon present in volatile
matter
• High total carbon represents high calorific
value of the fuel.

16. Hydrogen
• It increases calorific value-H2 remains as coke
oven gas
• Associated with volatile matter of coal
• Peat to bituminous contains 4.5-6% H2
• Anthracite contains only 1-2%

17. Nitrogen
• Present up to 1-3%
• Comes from protein us matter in vegetable matter.
• Inert nitrogen decreases calorific value.
• As coal matures, extractable nitrogen decreases.
• Its proportion does not depend on rank.
• It varies from 1-2% in all.

18. Sulphur
• It increases calorific value but is undesirable.
• Its oxidization product in presence of moisture cause
corrosion of equipment and pollution.
• When used in steel making it badly affects properties
of iron and steel.
• Sulphur exists in 3 forms-pyritic, organic & sulphate
• World coal contains 1 to 3% sulphur.

19. Oxygen
• Less the oxygen-better is the coal.
• Decreases from lignite to anthracite.
• As oxygen content increases, moisture holding
capacity increases and caking power
decreases.

20. Phosphorus
• Undesirable in metallurgical as it badly affects
properties of metals.
• Indian coking coals have less than 0.15%
phosphorus.

21. Fuels % C % H % O % N % S % Ash
Peat 23 10 59 1.5 0.5 6
Lignite 42 7 43 1 1 6
Bituminous 77 5 5 1.5 0.5 11
Sub-
Bituminous
59 6 29.5 1 0.5 4
Semi-
Anthracite
80 3.5 4.5 1.5 0.5 10
Anthracite 86.5 2.5 3 0.5 0.5 7
Ultimate Analysis – Constituents of Coal

22. Thank You