What are the advantages of bio gas over wood. Explain it.

Bio gas is a renewable source of energy but wood is non renewable source of energy. Both source can be used by burning but there are lots of advantages of using bio gas over wood which are as follows: 

1. Bio gas does not give smoke where as wood does when its burned. 
2. The requirement for production of bio gas is cheap while wood taken from the forest reduces biodiversity. 
3. bio gas gives more heat in comparison to the wood burned of same amount. 
4. The residue left over of bio gas is an excellent manure where as of wood is not. 

Biogas is a green energy source in form of electricity and heat for the local grid. Considerable environmental advantages - less emission of the greenhouse gasses methane, CO₂ and nitrous oxide. Environmentally friendly recirculation of organic waste from industry and households.Uses of biogas are: (i) It can be used for cooking food and other domestic heating purposes. (ii) It can be used for street lighting. (iii) It can be used to run small engines like water pumping sets for irrigation purposes.

When manure is anaerobically digested, the biogas produced is primarily composed of methane and carbon dioxide, with lesser amounts of hydrogen sulfide, ammonia, and other gases. Each of these gases has safety issues. Overall, biogas risks include explosion, asphyxiation, disease, and hydrogen sulfide poisoning.