Fuels made from plant and animal products is known as Bio mass.

Example - Wood, Cow Dung

 

These fuels do not produce much heat during burning and gives out a lot of smoke when they are burnt.

 

So, just burning wood and cow dung are not enough for our energy requirements.

 

Thus, technological advancements are made to improve the efficiency of these fuels

 

Improving Efficiency of burning Wood

When wood is burned in limited supply of Oxygen,

water and other volatile materials inside it get removed 

and Charcoal is left behind as residue.

 

Charcoal burns without flames, gives out less smoke and has higher heat generation efficiency

 

Similarly, to improve the efficiency of cow-dung,

we convert it into Bio Gas

 

Bio Gas

 

Cow-dung, vegetable waste, sewage and other residue after harvesting crops are decomposed in absense of Oxygen to give bio-gas.

Since the starting material is mainly cow-dung, it is also known as Gobar Gas.




Let's look at how a Bio-gas is produced in a Bio Gas Plant

 

Bio Gas Plant

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In a Bio-Gas plant

  • The plant is made of a dome like structure with bricks
  • A slurry of cow-dung and water is made in the mixing tank from where it is fed to the digester
  • Digester is a sealed chamber where there is no oxygen
  • Anaeorobic organisms in the digester break down down complex compounds of the cow-dung slurry
  • After 2-3 days of decomposition, gases like Methane, Carbon Dioxide, Hydrogen and Hydrogen Sulphide are generated
  • This Bio-gas is stored in the gas-tank above the digester, and it is drawn through pipes for their use
  • The slurry left behind is used as Manure, rich in Nitrogen and Phosphorous

 

Some important points about Bio Gas

  • It contains 75% Methane, so it is an excellent fuel
  • It burns without smoke and leaves no residue (like ash in wood, charcoal from coal burning)
  • It is also used for lighting
  • The slurry left behind is removed periodically and used as Manure - rich in Nitrogen and Phosphorous
  • Large scale utilisation of bio-mass provides a safe and efficient method of waste disposal

 

Is Bio-Mass Renewable or Non-Renewable?

Bio-Mass is a Renewable source of Energy as we can always grow more crops and trees and waste material needed to create Bio-Mass will always be there 

 

Advantages of Bio-Mass (Bio Gas?)

  • It produces an excellent fuel which can burn without smoke and

Disadvantages of Bio-Mass

 

Note: - Fuel and Energy are different things.

Fuel means anything which we burn to produce heat energy

 

 

 

  1. Class 10
  2. Chapter 14 Class 10 - Sources of Energy

About the Author

Davneet Singh's photo - Teacher, Computer Engineer, Marketer
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.