Atmospheric double column distillation method under reduced pressure and separation of n-butanol azeotrope of mibk

The present invention relates to a double column distillation under reduced pressure atmospheric distillation means n-butanol and separating azeotrope of MIBK. The vacuum tower distillation unit mainly consists of Tl, atmospheric tower T2, vacuum pumps, pressure pumps, heat exchangers and the reflux drum and other components. Distillation separation method comprising: a raw material mixture by vacuum pumps P1 fed to a vacuum tower T1, Fractional T1 bottoms reboiler into the bottom reboiler R1, as part of the material of the n-butanol product recovery; T1 overhead after the vapor stream is condensed by the condenser C1, A1 reflux drum collection portion back into the vacuum tower T1, fractional atmospheric distillation tower T2 is fed to the pressurized pump; T2 C2 overhead vapor stream is condensed by a condenser, reflux tank collecting A2 after partially back into the atmospheric tower T2, part of the material returns the vacuum tower T1; T2 atmospheric tower bottoms portion of the bottom reboiler into the reboiler R2, part of the material is taken out as product MIBK. The present invention employs a double column distillation under reduced pressure and atmospheric separation techniques, continuous operation, the process is simple, with high yield, high purity, and low material consumption.