Improvements relating to the separation of narrow boiling hydrocarbon fractions

摘要

Hydrocarbon mixtures occurring in petroleum &c. naphthas boiling over 65 DEG C. and consisting essentially of cyclohexane, benzene and one or more of the isoheptanes 2.2-dimethylpentane, 2.2.3-trimethylbutane and 2.4-dimethylpentane are fractionally distilled to separate the separate constituents by adjusting the amounts of benzene and the isoheptanes present (i.e. by adding benzene or one of the isoheptanes as the case may be) so that they are present in their azeotropic proportions, distilling the mixture so that the azeotropic minimum constant boiling mixture of the benzene and the isoheptane is recovered overhead and the benzene and isoheptanes separated in known manner by solvent extraction, fractional or extractive distillation. Specification 585,850 is referred to.