It occurs when a substoichiometric fuel-air mixture is partially combusted in a reformer, creating a hydrogen-rich syngas which can then be put to further use, for example in a fuel cell.
[1] The formulas given for coal and heating oil show only a typical representative of these complex fuels.
Yields are below stoichiometric due to some fuel being fully combusted to carbon dioxide and water.
[citation needed] In CPOX (catalytic partial oxidation) the use of a catalyst reduces the required temperature to around 800°C – 900°C.
[citation needed] The choice of reforming technique depends on the sulfur content of the fuel being used.