Question

Biogas is better than animal dung cake. justify this statement by giving three reasons.

Answer 1

     Animal dung cakes preparation requires sunlight and space.  That requires working with hands.  The dung cakes can be carried anywhere.  But the calorific value (heat obtained) is less in the cakes.  They generate CO and CO2 if they are not properly combusted.  This is usually the case.  So that results in pollution.  The dung cake burning results in ash.  Ash management is a problem usually.  It flies and falls on agricultural fields, and it is not good.  Soot particles burn eyes and pollute air.

    Biogas has high calorific value, clean, and supplies heat to where ever we want by a pipe.  The remains and leftovers of animal dung could be used as manure in cultivation of plants and crops. 

Answer 2

Biogas is better than animal dung cake. justify this statement by giving three reasons.

1. It doesn't leave any ash after burning.
2. It burns with smokeless flame.
3. It has higher calorific value than dung-cake, wood & coal.
4. It is much cheaper than most of the common fuel.
5. Use of Biogas as a fuel will save forests & fossil fuels.