Catalytic reforming is a chemical process used to convert
petroleum refinery naphthas distilled from
crude oil (typically having low
octane ratings) into high-octane liquid products called
reformates, which are premium blending stocks for high-octane
gasoline. The process converts low-octane linear hydrocarbons (paraffins) into branched alkanes (isoparaffins) and cyclic
naphthenes, which are then partially dehydrogenated to produce high-octane
aromatic hydrocarbons. The dehydrogenation also produces significant amounts of byproduct
hydrogen gas, which is fed into other refinery processes such as
hydrocracking. A side reaction is
hydrogenolysis, which produces light hydrocarbons of lower value, such as
methane,
ethane,
propane and
butanes. In addition to a gasoline blending stock, reformate is the main source of aromatic bulk chemicals such as
benzene,
toluene,
xylene and
ethylbenzene which have diverse uses, most importantly as raw materials for conversion into plastics. However, the benzene content of reformate makes it
carcinogenic, which has led to governmental regulations effectively requiring further processing to reduce its benzene content.