Axens offers a complete line of isomerization solutions that go far to meet tighter gasoline pool specifications by increasing C5/C6 naphtha cut octane numbers up to 92. The isomerate product is free of sulfur, aromatics and olefins, making it an excellent gasoline pool component. Isomerization fits well with the trend to remove benzene precursors from reformer feedstocks.
A complete range of schemes is available from Axens: once-through, recycle with diisopentanizer or with deisohexanizer, advanced recycle (IpsorbTM, HexorbTM). In these last options, the isomerization reaction section is coupled with an iso/normal paraffins separation step which enables n-paraffins to be recycled to extinction and octane gain to be maximized.
Typical payout times are on the order of a year. The question of which process to select will depend on a number of criteria such as feed composition and desired octane number.
At the moment, over twenty units have been licensed.
