Reforming, in chemistry, is a technique by which the molecular structure of a hydrocarbon is rearranged to alter its properties. The process is frequently applied to low-quality gasoline stocks to improve their combustion characteristics.
Thermal reforming alters the properties of low-grade naphthas by converting the molecules into those with higher octane numbers by exposing the materials to high temperatures and pressures. Catalytic reforming uses a catalyst, usually platinum, to produce a similar result.