The following reaction represents the combustion of methane: CH 4 [g] + 2 O 2 [g] -> CO 2 [g] + 2 H 2 O[g] + energy One molecule of methane, (the [g] referred to above means it is gaseous form), combined with two oxygen molecules, react to form a carbon dioxide molecule, and two water molecules usually given off as steam or water vapor during the reaction and energy. In general, for complete combustion: hydrocarbon + oxygen → carbon dioxide + water. This is represented by the following chemical equation : It means that 1 kg of carbon requires 8 / 3 kg of oxygen for its complete combustion, and produces 11 / 3 kg of carbon dioxide gas… Heat loss - 55-75% - in power generation is not included in the numbers. Note! See also Heat of combustion, Fuels - Higher and Lower Calorific Values and Fossil and alternative fuels - energy content. Here is the equation for the complete combustion of methane, used in Bunsen burners: For full table with Specific CO2 emission - rotate the screen! When carbon burns in sufficient quantity of oxygen, carbon dioxide is produced along with a release of large amount of heat. On combustion of fuel these elements are converted into gases like CO 2, H 2 O, SO 2 etc., Combustion of carbon : C + O 2 CO 2 (g) Emission of CO 2 from combustion of some common fuels are indicated in the table below.