In catalytic reforming, a mixture of hydrocarbons with boiling points between 60 and 200 °C is blended with hydrogen gas and then exposed to a bifunctional platinum chloride or rhenium chloride catalyst at 500–525 °C and pressures ranging from 8–50 atm. Under these conditions, aliphatic hydrocarbons form rings and lose hydrogen to become aromatic hydrocarbons. The aromatic products of the reaction are then separated from the reaction mixture (or reformate) by extraction with any one of a number of solvents, including diethylene glycol or sulfolane, and benzene is then separated from the other aromatics by distillation. The extraction step of aromatics from the reformate is designed to produce aromatics with lowest non-aromatic components. Recovery of the aromatics, commonly referred to as BTX (benzene, toluene and xylene isomers), involves such extraction and distillation steps.
In similar fashion to this catalytic reforming, UOP and BP commercialized a method from LPG (mainly propane and butane) to aromatics.