What is the secondary unit in an oil refinery that produces high octane gas?

The alkylation unit is designed specifically to produce high octane gasoline components by combining light hydrocarbons, such as isobutane and olefins, in the presence of an acid catalyst (usually sulfuric acid or hydrofluoric acid). This process creates larger branched-chain hydrocarbons that have high octane ratings, which are essential for formulating premium gasoline and meeting regulatory standards for fuel quality.

In contrast, while the catalytic cracker does contribute to gasoline production by breaking down larger hydrocarbon molecules into smaller ones, it primarily focuses on producing a broader range of gasoline and diesel products rather than specifically targeting high octane gasoline. The hydrotreater is mainly used for hydrotreating, which removes impurities such as sulfur and nitrogen from fuels but does not specifically enhance octane ratings. The visbreaking unit, on the other hand, primarily aims to reduce the viscosity of heavy oils, generating lighter products but not focusing on octane enhancement either.

Thus, the alkylation unit stands out as the key component in an oil refinery for producing high octane gasoline.