Types of fuels

1. 1

2.  High calorific value
 Moderate ignition temperature
 Low moisture content
 Low ash content
 Moderate velocity of combustion
 Harmless products of combustion
2
 A chemical fuel –combustible-containing
carbon-on burning gives large amount of
heat e.g. Petrol, Diesel, Coal, CNG, LPG,
Biodiesel.

3. 3

5.  Higher Calorific Value/ Gross calorific
value(HCV/GCV)
 Lower Calorific Value/ Net Calorific
Value(LCV/NCV)
 NCV=GCV-0.09×H×587 cal/gm or kcal/kg
5

7.  Principle of calorimeter
 Total heat liberated=heat absorbed by known
mass of water in calorimeter.
 Rise in temperature of water
7

9.  Heat liberated=heat absorbed by water,
apparatus
 X.L=(W+w)(t2-t1)
 L= (W+w)(t2-t1) cal/gm
 x
 L= 4.187 (W+w)(t2-t1) J/gm
 x
9

10.  Fuse wire correction(tf)
 Acid Correction(ta)
 Cooling Correction(tc)
 L= (W+w)(t2-t1+tc)-(ta+tf) cal/gm or kcal/kg
 x
 L= 4.187(W+w)(t2-t1+tc)-(ta+tf) J/gm or kJ/kg
 x
10

12.  VL= W(t2-t1)
 V
 V= volume of gas burnt
 W= Total mass of circulating water
 L= W(t2-t1)
 V
 NCV= GCV- Heat carried by steam
 How much heat is carried by steam?
12

13.  Coal- Highly carbonaceous matter
13
Wood Peat Lignite Bituminous Anthracite

14.  Analysis of Coal Proximate Analysis
Ultimate Analysis
14

15.  Determination of % moisture, volatile matter,
ash, fixed carbon
 A) % Moisture: 105-110°, 1hour
15

16.  %M= m-m1 Muffle Furnace
m
% Volatile Matter
925+ 20°C, 7 minutes
%Ash: 700+ 50°C, ½ hour
% Fixed carbon= 100-(%M +%VM +% ash)
16

17.  Moisture
 Volatile Matter
 Ash
 Fixed Carbon
17

18.  Determination of % of C,H,N,S,O and ash
 A. Estimation of Carbon and Hydrogen
 Combustion Method
 Coal burnt in pure dry O2 CO2 + H2O U-tube
 CaCl2 + 7H2O CaCl2.7H2O
 2KOH + CO2 K2CO3 + H2O
 %C= 12 ×Increase in weight of KOH tube× 100
 44 Weight of Coal
 % H= 2× Increase in weight of CaCl2 tube ×100
 18 Weight of Coal
18

19.  Kjeldahl’s Method
 Coal Conc. H2SO4 K2SO4 (NH4)2SO4 KOH NH3 NH4Cl
 1 N HCl= 1N NH3= 1equivalent N =14 g N
 1000 ml 1N HCl= 14 gm N
 (V2-V1)ml 0.1 N HCl =14 gm N
 %N= Volume of acid used ×Normality × 1.4
Weight of coal
19

20.  S Oxidation SO2 Oxidation SO3 H2O in Bomb Calorimeter H2SO4 BaCl2 BaSO4
 % S= 32 ×Weight of BaSO4× 100
 233 Weight of Coal
 Estimation of ash
 Estimation of Oxygen
 %O=100-(%C+%H+%S+%N+%ash)
20

21.  A. Carbon & Hydrogen
 B. Nitrogen
 C. Sulphur
 D. Oxygen
 E. Ash
21

22. Content Procedure Formula
% Moisture
Finely powdered coal in
crucible heated in hot air
oven at 105-110OC for 1 Hr.
% Moisture= Loss in weight * 100
Weight of coal taken .
% Volatile
Matter
Moisture free coal in crucible
is heated in muffle furnace at
925OC for 7-8 mins.
% V.M.=
Loss in weight due to removal of V.M.* 100
Weight of coal taken
.
% Ash
Residual coal heated
without lid in muffle furnace
at
700-720OC for ½ hr.
% Ash = Weight of ash left * 100
Weight of coal taken.
Fixed
Carbon
-
Fixed Carbon =
100 - % of (Moisture + Volatile Matter
+Ash)

23. %C = Increase in weight of KOH tube * 12 * 100
Weight of coal taken *44
% H = Increase in weight of CaCl2 tube * 2 * 100
Weight of coal taken *18

26. Petroleum
-Dark, sticky, greenish brown, viscous oil
rock oil
Composition
C = 80-87 %
H = 11-15 %
S = 0.1-3 %
N + O = 0.1-0.5 %
Classification
Paraffinic base type : Saturated hydrocarbons (C1-C35 )
Asphaltic base type : Cycloparaffins
Mixed base type : Paraffinic and asphaltic hydrocarbons

27. 27

28. 28

29. Natural
gas

30.  Petroleum is separated into its components by
fractional distillation alongwith the separation of
impurities.
 Step I: Separation of water (by Cottrell’s
Process): De-emulsification ---highly charged
electrodes
 Step II: Removal of harmful sulphur compounds
 Treatment of oil with copper oxide
 Step III: Fractional Distillation
30

32. 32

34.  When ethyl alcohol is used as fuels in I.C engine
,it is called as power alcohol.
 Manufacture of ethyl alcohol from sugar
molasses by fermentation
Sucrose to Glucose by Enzymes

C12H22O11 + H2O → C6H12O6 + C6H12O6
Glucose to Ethanol by enzymes
C6H12O6 → 2 CH3CH2OH+ 2 CO2 + heat

35.  Advantages
 Good anti-knocking property and octane number 90 ,
greater than petrol 65.
 Tendency to absorb the water if present in petrol.
 Ethyl alcohol contains ‘o’atoms, which help for
complete combustion of power alcohol
 and polluting emissions of co, hydrocarbon, particulate
are reduced.
 Our dependence on foreign countries for petrol is
reduced.
 Cheaper than petrol.
 Specially designed engine with higher compression ratio
used.

36.  Disadvantages:
 1)Lower C.V.(7000cal/gm) than C.V. of petrol(11500 cal/gm) ,
 power output reduces to 35%.
 2)At lower temp., it can cause starting trouble due to atomization
and high surface tension.
 3)It can undergo oxidation to form acetic acid, which leads to
corrosion of engine parts.
 4)Carburetor and engine needs to be modified, when only ethyl
alcohol is used as a fuel.
 5) Ethyl alcohol obtained by fermentation process directly cannot
be mixed with petrol but it has to be dehydrated first.


37.  Biodiesel, chemically, is the mixture of
methyl esters of long chain carboxylic
acids, obtained by trans esterification of
vegetable oil, animal fat, or sodium
methoxide
 Biodiesel can be obtained from various
vegetable oils like soyabean oil, palm oil,
groundnut oil, sunflower oil etc.

40.  Properties & Advantages: It is cheaper than
other fuels.
 It has high cetane numbers 46-54 &C.V.
=40kj/gm.
 It is regenerative and environment friendly.
 Presence of ‘o’ complete combustion occur and
reduces possibility of pollution due to ‘CO’.
 It helps to reduce the dependence on other
countries for diesel.
 It has certain extent of lubricity ,due to higher
oiliness of ester.
 It is clean to use biodiesel in diesel engine.

41.  Limitations:
 1)Cloud and pour points of biodiesel are higher
than diesel and can cause problem in flow line.
So it cannot be used in cold regions.
 2) Biodiesel may have dissolving action rubber
hoses, gaskets.
 3) Biodiesel adhere metal strongly which leads
to form gummy residue.
 4) There is no control on prices of vegetable oil
so cost of biodiesel fluctuate

43. A. Production from fossil sources
• Steam reforming of methane
• Steam reforming of coke

44.  CH4 + H2O Ni CO + 3H2
 700-1000°C
 Water gas shift reaction
 CO + H2O Fe/ Cu 400°C CO2 + H2
A. Production from fossil sources
• Steam reforming of methane
• Steam reforming of coke

45.  C + H2O 1000°C CO + H2
 Water gas shift reaction
 CO + H2 steam Fe2O3, 2H2+ CO2
 450°C

46.  Physical storage- via compression,
liquifaction, adsorption on porous carbon
material
 Chemical storage- in the form of metal
hydrides and sodium alanate

47.  In the form of compressed H2
 H2 = intensely pressurized to several
atmospheres & stored in pressure vessel
 Compression requires 2.1% energy content

48.  H2 can be stored at very low temperature
 Special tanks to keep H2 cold and prevent
losses
 Cryogenic H2 tanks are lighter
 More energy required to liquify
 Tanks must be insulated

49.  Small size
 Large surface area
 High porosity
 Low density

50.  In form of metal hydrides
 Metal hydride Δ Metal + H2
 No rapid uncontrolled release of H2
 H2 storage and release at low temperature
pressure
 PEM fuel cell: 1-10 atm, 25-120°C
 LaNi5H6
 NaAlH4

51.  Storage capacity 5.5wt%
 3NaAlH4 Na3AlH6(s) +2Al(s) + 3H2(g)
 3.7wt % hydrogen is released @ 1 atm >33°C
 2Na3AlH6 6NaH(s) +2Al(s) 3H2(g)
 (1.8 wt % hydrogen is released) @ >110°C
 Low H2 capacity
 Slow uptake and release kinetics
 cost

52.  Difficulties with compressed H2
 High pressure tanks
 Large tank
 Weight
 Difficulties with liquified hydrogen
 More energy required to cool and liquify
hydrogen
 Good tank insulation
 Adds to weight volume and cost

53.  As a fuel
 In oil refining
 In production of NH3
 In metal production
 In welding
 In food industry
 As a feedstock for chemicals
 In glass and ceramics

54.  Available from renewable resources
 It is nontoxic and clean burning fuel
 It shows high energy output
 As rocket fuel
 Fuel for vehicles
 Fuel cell better than battery: Long life