间歇精馏分离丁酮与甲基异丁基酮

Separation of butanone and methyl isobutyl ketone by batch distillation

采用恒回流比、累加回流比及循环全回流常压间歇精馏分离丁酮(MEK)甲基异丁基酮(MIBK)混合液,研究恒回流比操作下馏分组成对塔顶和塔釜温度的影响及各操作方式下产品质量分数以及MEK和MIBK回收率。研究结果表明:恒回流比操作下塔顶、塔釜温度均随馏分浓度降低而升高,过渡馏分采出阶段塔顶温度上升24℃,塔釜温度上升0.3℃;当回流比由1增加到2和3时,过渡馏分量分别减少4.91%和11.52%,轻、重产品质量分数分别提高3.08%和1.12%,MEK和MIBK回收率分别提高15.44%和5.72%;累加回流比时,过渡馏分量较回流比为1时减少19.90%,轻、重产品质量分数分别提高3.44%和1.48%,MEK和MIBK回收率分别提高27.55%和8.55%;循环全回流方式下,过渡馏分量较回流比为1时减少38.92%,轻、重产品质量分数分别提高3.73%和0.97%,MEK和MIBK回收率分别提高42.43%和13.79%。采用不同方式均可得到质量分数大于95.0%的轻重组分。

The separation of butanone （MEK） and methyl isobutyl ketone （MIBK） mixture by constant reflux batch distillation, accumulative reflux batch distillation and cyclic total reflux batch distillation were studied. The effect of distillate composition on top and bottom temperatures at constant reflux ratio was investigated. The purities and recoveries of MEK and MIBK were also studied. The results show that both the top temperature and bottom temperature increase with the decrease of the mass fraction of MEK in distillate. The top temperature and bottom temperature increase by 24 ℃ and 0.3 ℃ respectively during slop cut collecting. As the reflux ratio increases from 1 to 2 and 3, the amount of slop cut decreases by 4.91% and 11.52%, the purities of distillate and bottom product increase by 3.08% and 1.12%, and the recoveries of MEK and MIBK increase by 15.44% and 5.72%, respectively. Compared with constant reflux distillation at reflux ratio 1, the amount of slop cut can be decreased by 19.90%, the purities of distillate and bottom product can be increased by 3.44% and 1.48%, and the recoveries of MEK and MIBK can be increased by 27.55% and 8.55%, respectively, by the accumulative reflux ratio batch distillation. Compared with constant reflux distillation at reflux ratio 1, the amount of slop cut can be decreased by 38.92%, the purities of distillate and bottom product can be increased by 3.7% and 1.0%, and the recoveries of MEK and MIBK can be increased by 42.43% and 13.79%, respectively, by the total reflux batch distillation. Both the mass fraction of distillate product and bottom product can be greater than 95% by each of the above batch distillation.