甲醇-乙醇-水三元系精馏分离流程研究

提出了甲醇 乙醇 水三元系的分离问题。计算结果表明 ,足够量甲醇的存在可破坏乙醇和水之间的共沸现象 ,使采用普通精馏制取高浓度乙醇成为可能。当甲醇浓度大于 0 .6 15摩尔分率时 ,乙醇和水之间的共沸点完全消失。可通过循环甲醇调整进料中甲醇的含量 ,一定量甲醇的循环可显著降低精馏塔的投资费用。在示例中 ,有甲醇循环时的最小塔费用仅相当于无甲醇循环时的 40 %。实验结果证实了流程的可行性 ,相近的流程已应用于工业生产中。

Study on Separation Flowsheet of Methanol-Ethanol-Water Ternary System by Distillation

Methanol and ethanol are often used in industry,which easily form mixtures with water.Therefore,the problem of recovering methanol and ethanol from the mixtures exists.The calculating results show that the sufficient amount of methanol in the system can break the azeotropic phenomenon between ethanol and water,which makes it possible to obtain high concentration ethanol only using general distillation.The azeotropic behavior completely disappears when the methanol content in the mixtures is larger than 0.615(mol fraction). The methanol content in feed can be changed by methanol recycle.The proper amount of methanol recycle can reduce the cost of the distillation columns significantly.The minimum cost with methanol recycle is only about 40% of that without methanol recycle in this case. The experiment confirms the feasibility of this flowsheet.The similar one has been put into practice successfully.