Notesale: Turn your study into money

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Otto Hoffmann method / metallurgical coke
Metallurgical coke:
• When bituminous coal is heated strongly in the absence of air and it
becomes hard and strong, which is called metallurgical coke
...
(10–12 m length; 3-4m
height; 0
...
45 m wide)
• Coal taken in chambers and it is heated by preheated air and producer
gas at 1200°C
...

• Hot flue gases i s produced during carbonization , and it is passed
th
st
regenerators up to 1000°C
...

• After 24 h, the above process is completed, and the coke is removed
and i t i s quenched with water
...
And the valuable by-products such as tar, ammonia,
H2S and benzene, etc can be recovered from flue gas
...
Here tar and dust are gets dissolved, and it
is collected
• Ammonia at tower 2:
o The coal gases are passed thro’ tower 2, in which water is
sprayed
...

• Naphthalene at tower 3:
o The coal gases are passed thro’ tower 3, in which cooled water
is sprayed
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• Benzene at tower 4:
o The coal gases are passed thro’ tower 4, in which petroleum is
sprayed
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• H2S at tower 5:
o The remaining coal gases are passed thro’ tower 5, in which
Fe2O3 is Packed
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• Finally pure coal gas left out, and it is used as a gaseous fuel
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• Ethyl alcohol is used in internal combustion (IC) engine
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Manufacture
• Manufacturing of power alcohol involves two steps
Step – 1: manufacture of ethyl alcohol
• Ethyl alcohol can be synthesized by fermentation of molasses (residue of
sugar) with yeast
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C6H12O6 ( in presence of yeast )
→ C2H5OH + 2 CO2
•
• Concentration of alcohol can be increased up to 97
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• This constant boiling mixture has a lowering B
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Step – 2: Conversion of ethyl alcohol into power alcohol
• 100 % alcohol is prepared by removing last traces of water from rectified
spirit
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o Alcohol is distilled in the presence of dehydrating agent, which
removes the water
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cal/Kg
• It has octane number 90
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• It generates more power than gasoline
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Bio Diesel
• Bio – diesel is defined as mono-alkyl esters of long chain fatty acids derived
from vegetable oils
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• Triglycerides are ester of long chain fatty acids
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Manufacture: Trans – Estertification (or) Alcoholysis
• Trans – Estertification (or) Alcoholysis is the process to reduce the viscosity
of vegetable oil
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• Finally methyl esters of fatty acid is formed, are called “Bio – Diesel”
Alcoholysis reaction is represented as follows

Advantages of Bio-diesel
• Bio-diesel is bio-degradable
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• The gaseous pollutants are lesser in bio-diesel
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• Best engine performance
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Disadvantages
• It becomes gel in cold winter
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• It decreases horse power of engine
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• Emission of NO2 is higher than conventional energy
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Definition - Hydrogenation of coal
• When the coal is heated with hydrogen to higher temperature under high
pressure, it is converted to gasoline
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• Bergius process (or) direct method is one of the methods available for the
hydrogenation of coal
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• The paste is pumped along with hydrogen gas into the converter, which is
heated at 400-450 °C, 200 – 250 atm
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And it is decomposed into mixture of lower hydrocarbons
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• The crude oil is then fractionated to yield, (i) Gasoline (ii) Middle oil (iii)
heavy oil
• The middle oil is further hydrogenated to yield more gasoline
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• The yield of gasoline is about 60% of the coal

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