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close this bookBetter Farming Series 31. Biogas: What it is; How it is Made; How to Use it (FAO Better Farming Series, 1984)
View the document(introduction...)
View the documentPreface
Open this folder and view contentsIntroduction
Open this folder and view contentsHow to build a small biogas unit
Open this folder and view contentsWaste materials
View the documentTime
View the documentCold weather protection
View the documentStirring the waste mixture
View the documentWhen the gas is made
View the documentUsing your biogas
View the documentUsing the fertilizer
View the documentTaking care of your biogas unit
View the documentMaking more biogas

Using your biogas

107. The best way to use the biogas that you make with your small biogas unit is for cooking. When your unit is working well, it will make enough gas every day to cook your evening meal.

108. You can use biogas with almost any ordinary gas- burner, if you adjust the burner so that the right amount of air is mixed with the biogas.


Adjust air mix

109. If there is too much air, the flame will be blown out and the biogas will not burn. If there is not enough air, the flame will be yellow, the biogas will not burn well and will not give enough heat.

110. When there is the right amount of air and the biogas is burning well, it will burn with a blue flame. By letting more or less air into the burner, try to make the flame as blue as you can.

111. Sometimes the flame may begin to turn yellow after it has been burning well. This may mean that the burner has become full of a black material called soot.

112. If this happens, clean the burner very carefully and clean all the holes in the burner with soap and water. Dry the burner well. This may help your biogas


Clean burner

113. If the flame is not steady, or if it is weak when there is still gas in the unit, this may be because there is water in the burner or the gas line.

114. Shut off the gas at the small drum and take off the burner. Empty out any water that is in the gas line or in the burner. Then put the burner back, turn on the gas and light the burner again.


Shut off gas


Empty out water