Chemistry of Fuels, Proximate and ultimate analysis, Bomb Calorimeter, Otto-Hoffaman method, Synthetic petrol, Octane number, Cetane number, Antiknocking, Coal gas, Oil gas, Junkers Calorimeter, Dulongs Formula and Numerical Problems

1. Unit-2: Organic Fuels

2. Fuel is a combustible substance which on burning is capable
of releasing large amount of heat.
In chemistry, fuel is a material that contains carbon and
hydrogen and usually other elements such as nitrogen, sulfur
and oxygen.
Organic Fuels: Definition

6. Solid Fuels: Definition
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.
Examples of Solid Fuels:

8. It is highly carbonaceous matter &
is mainly composed of H, O, N, C.
Classification of coal: Anthracite,
Lignite, Bituminous and Peat.
When coal is heated in absence of
air, the porous, hard and strong
residue left is called
“Coke”.

9. Carbonization Process
Heat
Absence of Air
X

10. Coal Coke
It burns with long flame It burns with short flame
Sulfur is present Sulfur is not present
Less strong More strong
Less porosity More porous

11. Classification of Coal

13. Coal Mining and Coal Workers

16. Coal Transportation

20. In order to get good quality of fuel its analysis is required.
The quality of fuel is analyzed by two methods.

26. KOH Tube
CaCl2 Tube

28. Nitrogen Determination by Kjeldahl Method
The Kjeldahl procedure involves three major steps:

29. 1. Digestion
Coal
Ammonium Sulfate

30. 2. Distillation
During the distillation step the ammonium ions
(NH4
+) are converted into ammonia (NH3) by
adding alkali (NaOH).

31. 3. Titration
When using sulfuric acid standard solution as absorbing solution,
the residual sulfuric acid (the excess not reacted with NH3)
is titrated with sodium hydroxide standard solution and by
difference the amount of ammonia is calculated.

32. Nitrogen Determination by Kjeldahl Method

33. Phenolphthalein indicator

34. Determination of percent sulfur (% S) in Coal

36. 4
Determination of percent oxygen (% O) in Coal

37. What is the significance of ultimate analysis of coal?
Ultimate analysis provides a convenient method for reporting the major organic
elemental composition of coal. For this analysis, a coal sample is combusted in an
ultimate analyzer, which measures the weight percent of carbon, hydrogen, nitrogen,
and sulfur from a coal sample.

43. Unit-2: Organic Fuels

44. Gross Calorific Value and Net Calorific Value
GCV NCV
lower heating value (LHV)
lower calorific value (LCV)Higher calorific value (HCV)
Higher heating value (HHV)
GCV is the amount of heat released by
the complete combustion of a unit
amount of fuel.
NCV = GCV - heat of vaporization of
the water vapour

49. What is Metallurgical Coke?
Metallurgical coke is made from low ash, low sulfur bituminous coal, with
special coking properties, which is inserted into ovens and heated to 10000F.
Metallurgical coke or coking coke is used in the process of creating coke necessary
for iron and steel-making.

50. ➢ Modern Process developed by Otto-Hoffman
➢More Better than Beehive Process
➢Less time is required for carbonization
➢Valuable By-products are easily obtained in this process
➢This oven works on “heat economy” and thermal efficiency is increased.
➢Regenerative principle of heat economy is used in this method

60. Mining of Petroleum

61. India produced 35.68 MTs of crude petroleum in 2017–18. India accounted for 0.92%
of world oil production in 2016–18. The production of natural gas was 31.73 billion
cubic meters in 2017–18, growing by 60.86% over the previous year. ONGC owns
participating Interests in 37 oil and gas assets in 17 countries and produced about 30.3%
of oil and 23.7% of oil and natural gas of India's domestic production in 2019-20.
In terms of reserves and production, ONGC is the second largest petroleum
company of India.

64. Indian Oil Corporation (IOC) is the largest domestic refiner with a capacity of 80.7
MMTPA. Top three companies – IOC, Bharat Petroleum Corporation (BPCL) and
Reliance Industries (RIL) - contribute around 66.7% of India's total refining production
from FY 2018 - 19.

71. Unit-2: Organic Fuels

72. Cracking of Petroleum
In petrochemistry, petroleum geology and organic chemistry, cracking is the process
whereby complex organic molecules such as long-chain hydrocarbons are broken down
into simpler molecules such as light hydrocarbons, by the breaking of carbon-carbon
bonds.

73. Thermal Cracking
At high temperature……

74. Catalyst
Catalytic Cracking
In presence of catalyst……..

76. Cracking is the most important process for the commercial production of gasoline
and diesel fuel.

82. Chemistry
The Fischer-Tropsch process is a catalytic chemical reaction in which carbon monoxide
(CO) and hydrogen (H2) in the syngas are converted into hydrocarbons of various
molecular weights according to the following equation:
(2n+1) H2 + n CO → Cn H(2n+2) + n H2O
Where n is an integer. Thus, for n=1, the reaction represents the formation of methane,
which in most CTL or GTL applications is considered an undesirable byproduct. The
Fischer-Tropsch process conditions are usually chosen to maximize the formation of
higher molecular weight hydrocarbon liquid fuels which are higher value products. There
are other side reactions taking place in the process, among which the water-gas-shift
reaction
CO + H2O → H2 + CO2
is predominant. Depending on the catalyst, temperature, and type of process employed, hydrocarbons ranging
from methane to higher molecular paraffins and olefins can be obtained. Small amounts of low molecular weight
oxygenates (e.g., alcohol and organic acids) are also formed. The Fischer-Tropsch synthesis reaction, in theory, is
a condensation polymerization reaction of CO.

84. Reforming of Petroleum

85. 1. Isomerization:
2. Aromatization:

86. 3. Cyclization:
Reforming is the process in which structural
modifications are done in the molecules to
improve the Antiknocking characteristics.

87. 4.

88. Normal Knocking

90. • Knocking property is expressed as “octane number” or
“octane rating”
• The tendency to knock depends not only on the fuel but also
on the engine design, shape, location of plug and port etc.
• Knocking tendency of paraffin's increases with the increase in
the length of carbon chain.
• Knocking property decreases with the increase in the number
of C=C and rings.

101. Unit-2: Organic Fuels

110. Calorific Value of Coal Gas

113. Production of Oil Gas