(i) It burns without smoke and leave no residue therefore causes no atmospheric pollution. (ii)Its heating capacity is high, i.e. it has high calorific value. Main constituents of bio gas: The composition of bio gas varies depending upon the nature of organic matter feeding in’the digester and advanced waste treatment technology. The typical composition of bio gas is
| Methane |
50 – 75% |
| Carbon dioxide |
25 – 50% |
| Nitrogen |
0 – 10% |
| Hydrogen |
0 – 1% |
| Hydrogen sulphide |
0 – 3% |
