Catalytic reforming converts low octane straight run naphtha fractions, especially heavy naphtha that is rich in naphthenes, into a high octane, low sulfur reformate, which is a major blending product for gasoline. Hydrogen is the most valuable byproduct from catalytic reforming and is used for the increasing demand for hydrogen in hydro treating and hydrocracking processes. The feedstock for the catalytic reforming is straight run heavy naphtha that is separated in the naphtha fractionator of the Light Ends Unit. The naphtha feedstock needs to be hydro treated before reforming to protect the catalyst from being deactivated by depositing nitrogen and sulfur on the surface of the platinum. This naphtha from the fractionator, inherently has a low octane number and can be sent directly to the gasoline pool after being hydro treated or sent to an isomerization process.  A Platinum or bimetallic catalyst on a metal oxide support is used for the reforming process. The United States and Europe are setting regulations for a total limit of aromatics and benzene that is allowed to be in fuels. The amount of reformate that can be used in gasoline has also been limited. These regulations have led to the use of alkylate as an octane booster over catalytic reforming. Alkylate does not contain any olefinic or aromatic hydrocarbons.

The main purpose of this process is to increase the octane number of heavy naphthtas. In doing so, the conversion of napthenes to aromatics and isomerization of n-paraffins to i-paraffins must be performed to increase the octane number. The higher octane allows engines to run at higher compression ratios that produce more energy for car engines as well as aviation engines. The desirable outcomes of the catalytic reforming reactions are dehydrogenation, dehydroisomerization, dehydrocyclization, and isomerization. The first three reactions will promote the production or separation of hydrogen as well as aromatize the compounds to boost the octane number. The fourth, isomerization, is where the n-paraffin rearranges itself from a straight chain to an i-paraffin.