How many kilos of standard coal does a cubic meter of biogas equal to? How many kilos of standard coal can be saved by daily production of 1000 cubic meters of biogas? What is the best explanation basis?

How many kilos of standard coal does a cubic meter of biogas equal to? How many kilos of standard coal can be saved by daily production of 1000 cubic meters of biogas? What is the best explanation basis?

One cubic meter of biogas is equal to 0.714 kg of standard coal; 1000 cubic meters of biogas per day can save 714 kg of standard coal
The calorific value of methane per cubic meter is 20514kj. The calorific value of standard coal is 29306kj
20514/29306=0714