FarmersJoint.com

The following applies to biogas containing:
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Methane (CH4): 50-70 vol.%, carbon dioxide (CO2): 28-48 vol.%, other gases: up to 2 vol.%.
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1 kg firewood = 200 litres (0.2m3) biogas.
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2. 1 kg dried cow dung = 100 litres (0.1m3) biogas. Note: Some people use dried cow dung as fuel in cooking, e.g. India.
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3. 1 kg charcoal = 500 (0.5m3) liters biogas.
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4. 1m3 of biogas is equivalent to 0.45 litre of petrol, 0.55 litre of diesel, 0.60 litre of kerosene, or 0.5 kg of LPG.
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You can use this data to determine how much fuel biogas will save you. From that you can calculate the worth of your biogas in terms of money.


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1 kg charcoal = 500 (0.5m3) liters biogas.?

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Yes, in terms of energy content. It simply means that 500 Liters (0.5m3) of biogas will cook the same quantity of food as 1 kg charcoal.

I'm yet to see anyone that actually uses biogas.