METHOD OF ISOMERISATION OF LIGHT GASOLINE FRACTIONS Russian patent published in 2014 - IPC C07C5/22 C07C5/13 C07C9/16 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of isomerisation of light gasoline fractions, which consists of the preparation of straight-run and secondary gasoline fractions for isomerisation, with the further separation of raw isopentane in the first rectification column - deisopentaniser, after that, its supply to isomerisation in an isomerisation reactor with further release of gases and reflux in the second rectification column - debutaniser, from the bottom of which a stable isomerisate is supplied successively for the separation into the third rectification column for the separate extraction of isopentane and pentane and to the fourth rectification column for the separate extraction of isohexanes and hexane, side runs of the third and fourth rectification columns, containing respectively, pentane and hexane are recirculated for isomerisation into the isomerisation reactor. As a raw material used are straight-run and secondary gasoline fractions 40÷75…85°C, preparation and supply to isomerisation of the straight-run gasoline fraction 40÷75…85°C is carried out separately from the gasoline fraction 40÷75…85°C of the secondary processes of oil refining, with the gasoline fraction 40÷75…85°C of the secondary processes being supplied into the second or third rectification column.

EFFECT: application of the claimed method makes it possible to increase resources of the isomerisation process raw material due to the involvement into the process of the gasoline fraction of the secondary processes, output of target isohexanes, octane number of the isomerisate and isopentane fraction mixture and resources of high-octane semiproducts for compounding commercial gasoline.

5 cl, 3 tbl, 3 dwg