| 摘要 |
PURPOSE:To recover butadiene essentially free from non-condensing gas and moisture, in high yield, from a gas obtained by the oxidative dehydrogenation of n-butene and containing a non-condensing gas at a high concentration, by treating the raw gas by a specific process. CONSTITUTION:Butadiene is produced by the vapor-phase catalytic oxidative dehydrogenation of n-butene. The produced gas containing water and butadiene and having a non-condensing gas concentration of >=65mol% is made to contact with a hydrocarbon-based absorption solvent having a boiling point of 110-180 deg.C (preferably an aromatic hydrocarbon such as toluene, ethylbenzene, xylene, etc.) to allow the absorption of butadiene in said solvent. The non-condensing gas absorbed in the solvent is removed, and thereafter, water is removed therefrom. The treated absorption solvent is supplied to a dissipation column, and the butadiene is evaporated at a column pressure of 0.5-5kg/cm<2>G and a column bottom temperature of 110-190 deg.C. EFFECT:The accumulation of water in the dissipation column can be prevented to assure the safe operation. The loss of the solvent can be minimized.
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