Process for the preparation of very pure isobutene combining a reactive distillation hydroisomerisation and an isomerisation of the carbon skeleton

摘要

A process for the treatment of a charge comprising mainly 4C olefinic hydrocarbons, including isobutene, 1-butene and 2-butenes in a ratio corresponding to thermodynamic equilibrium. The charge is treated in a distillation zone coupled with a reactive hydro-isomerisation zone from the head of this zone an isobutene-rich effluent is obtained and from the base an effluent rich in 2-butene. The latter is directed to a zone of skeletal isomerisation the effluent from thus being re-cycled to upstream of the distillation zone.