Ideal
methane combustion in oxygen will lead to CO2 and water as
products:
CH4
+ 2 O2 -> CO2 + 2
H2O
As
most combustion processes are done in air, there is always the formation of
nitrogen oxide (NO). Natural gas is made up of 70-90% methane, with a 0-20%
content of ethane, propane and butane. In the ideal case, these gases also
burn
cleanly to form just carbon dioxide and water. In natural gas, there are
other
contaminants such as N2, H2S leading to the
production of
other products such as NO and SO2. Methane is thus
the
cleanlier burning gas.
An
even cleaner solution would be to burn Hydrogen (H2). There,
water
is the only product of a clean burning, and no CO2 is
produced.
2
H2 + O2 -> 2
H2O
The
problem of NO remains, when hydrogen is burnt in air rather than oxygen
(O2).
Another concern about the environmental impact besides the actual burning
may
be how the gas is obtained or produced.