US Patent 7223898 Isomerization process

A process for the isomerization of a feedstream comprising C5–C6 hydrocarbons where the process involves charging hydrogen and a feedstream comprising at least normal C5–C6 hydrocarbons into an isomerization zone and contacting said hydrogen and feedstream with an isomerization catalyst at isomerization conditions to increase the branching of the feedstream hydrocarbons and produce an isomerization effluent stream comprising at least normal pentane, normal hexane, methylbutane, dimethylbutane, and methylpentane has been discovered. Without passing through a stabilizer, the isomerization effluent stream is passed to a deisohexanizer zone to generate at least a stream enriched in methylbutane and dimethylbutanes. The stream enriched in methylbutane and dimethylbutanes is passed to an isomerate striper column to remove butane and lighter hydrocarbons and gasses. The remainder containing the methylbutane and dimethylbutanes is collected for use in, for example, gasoline blending.