15:- Bio-gas 
Aim :- to know about Bio-gas .
Requirement :- notepad etc.
Procedure :- bio gas is made or been produce from the cow dung .there are two type of Bio-gas plants . 1) floating dome type  2) fix dome type .
* In floating dome if there is any problem then we can fix it.hole set up to repair the problem
* Floating dome is better then the fix dome .
* It contains organic bacteria that eats the cow dung and generate gas from it .
* In that 60 -10 ml to 40.16 ml other gases are found .
* In bio-gas if we store 1kg cow dung we have to put 1liter water .
* The bio-gas in the bio-gas called as story can be used as fertilizer in fram.