Stoichiometric Combustion

Stoichiometric combustion is the burning of fuel with the exact amount of oxygen needed for complete reaction, leaving no unburned fuel and no excess oxygen. It is the theoretical air-fuel ratio against which real combustion is measured.

The stoichiometric ratio is fixed by the fuel's chemistry — for example, methane needs two molecules of oxygen per molecule of fuel. Real burners run slightly lean of stoichiometric to guarantee complete combustion, because perfectly stoichiometric mixing is impossible and any local fuel-rich pockets would produce soot and carbon monoxide. The stoichiometric point is the reference for setting excess air and for the highest possible adiabatic flame temperature.

Related terms

Excess Air · Adiabatic Flame Temperature · Boiler Efficiency