Pyrolysis gasoline

Pyrolysis gasoline or pygas is a naphtha-range product with high aromatics content. It is a by-product of high temperature naphtha cracking during ethylene and propylene production, a high octane number mixture that contains aromatics from the aromatization reactions, olefins, and paraffins ranging from C5s to C12s. The mixture has its own CAS Number: 68477-58-7.
Pygas has high potential for use as a gasoline blending mixture and/or as a source of aromatics. Currently, pygas is generally used as a gasoline blending mixture due to its high octane number. Depending on the feedstock used to produce the olefins, steam cracking can produce a benzene-rich liquid by-product called pyrolysis gasoline. Pyrolysis gasoline can be blended with other hydrocarbons as a gasoline additive, or distilled to separate it into its components, including benzene.
Raw pyrolysis gasoline is rich in benzene and is usually subjected to hydrogenation. Hydrogenated pyrolysis gasoline is a common feedstock of BTX plants for benzene and toluene extraction.