Completar frases HYDROCARBON COMBUSTION CCMVersión en línea Combustion where the chemical equation is balanced and the type of combustion is identified. por Leticia López 1 The formula of methane gas is and it is one of the components of natural gas , which is up to 80% in it . Another of the gases that make up natural gas is propane , whose combustion reaction is the following C3H8 + O2 - - - - - > CO2 + H2O + Energy , which is why combustion is carried out , characterized by a flame . This fuel comes from oil , but it must be separated by fractional distillation in Refineries . Another of the fuels used is heptane , which when there is a shortage of oxygen , the following reaction is carried out C7H16 + O2 - - - - - > CO + H2O , observing a flame , characterized by combustion . Another example would be the combustion of heptadecane C17H36 + O2 - - - - - > C + H2O , which from the by - products we can see that it is an combustion and it is evident that little energy will emanate . Finally , chemists are investigating the use of nonane as a fuel for internal combustion automobiles and whose combustion is C9H20 + O2 - - - - - > CO2 + H2O , from which a large amount of energy is obtained .