Sub-Product

Isomerization processes have been used to isomerize n-butane to iso-butane used in alkylation and C₅/C₆ n-paraffins in light naphtha to the corresponding iso-paraffins to produce high-octane number gasoline stocks after the adoption of lead-free gasoline.

Catalytic isomerization processes that use hydrogen have been developed to operate under moderate conditions. Typical feedstocks for isomerization process include hydrotreated light straight-Run Naphtha, light natural Gasoline, or condensate. The fresh C₅/C₆ feed combined with make-up and recycled hydrogen is directed to a heat exchanger for heating the reactants to reaction temperature. The heated feed is sent to the reactor. Typical Isomerate product (C₅+) yields are 97 wt% of the fresh feed, and the product octane number ranges from 81 to 87, depending on the flow configuration and feedstock properties.

Source: Isomerization, PennState College of Earth and Mineral Sciences