US Patent 7777089 Hydrocarbon separation

Process for the separation of close boiling isomeric compounds comprising distilling a dilute solution of isomers in a high boiling compound in the presence of a solid adsorbent. Multi and/or monobranched as well as cyclic isomers are withdrawn at the top of the distillation column, while straight chain and/or mono branched isomers are retained within the solid adsorbent. The diluent solution of the high boiling compound is withdrawn from the bottom of the distillation column and recycled, where it may be combined with the feed isomer mixture or recycled straight to the top of the adsorption column.