The distillation of crude oil provides a gasoline fraction of too low quality to be used directly as automobile fuel. The quality can be improved in the refinery by the catalytic reforming process. This process converts fractions of low octane number (40-60) into fuels of high octane number (95-105). Moreover, the catalytic reforming provides most of the hydrogen used by the hydrotreatments and gives petrochemistry aromatic hydrocarbones.