Method for separating mixture of ethanol alcohol and water

A mixture and ethanol technology, applied in the preparation of organic compounds, chemical instruments and methods, preparation of hydroxyl compounds, etc., can solve the problems of high energy consumption, equipment corrosion, and high production costs, and achieve low energy consumption, easy operation, and easy recovery. Effect

CN103435445AInactive Publication Date: 2013-12-11TIANJIN CLEANTECH TECH
7 Cites 19 Cited by

Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2013-12-11
Estimated Expiration
Not applicable · inactive patent

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
Patent Text Reader

Abstract

The invention provides a method for separating a mixture of ethanol alcohol and water. The method comprises the following steps: the mixture of the ethanol alcohol and water at any ratio is used as a raw material, an ionic liquid or a compound solvent comprising the ionic liquid and an organic solvent is used as an extracting agent, the ethanol alcohol and the water are sequentially extracted after the raw material is processed in the extractive distillation stage and the extracting agent recovering stage, and the extracting agent can be recycled after being extracted in the recovering stage. The method provided by the invention has the advantages of low energy consumption, no pollution to the environment, high production purity, easiness in industrialization, low equipment cost, good economic return and the like.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention belongs to the technical field of ethanol-water mixture separation, in particular to a method for separating ethanol-water mixture. Background technique

[0002] Ethanol is an important raw material for chemical synthesis and an organic solvent. Due to its wide application and large demand, its preparation technology and purification method have become research hotspots in academia and industry. In particular, the ethanol-water system forms an azeotrope. It is difficult to obtain high-purity ethanol by ordinary rectification. Special rectification should be used, such as azeotropic rectification, extractive rectification and membrane extraction technology. Because azeotropic distillation consumes a lot of energy; the cost of membrane in membrane extraction technology is high and regeneration is difficult, which limits its industrialization. Therefore, extractive distillation is often used in industry to separate ethanol-water systems. ...

Examples

Embodiment 1

[0032] According to attached figure 1 As shown in the process flow, there are 40 theoretical plates in the rectifying tower, the raw material contains 27% ethanol (mass fraction, the same below), and 73% water, and the flow rate is 1000kg / hr from the 35th theoretical plate of the rectifying tower (from the top of the tower to the Calculation at the bottom of the tower, the same below) feed, the extractant 1-ethyl-3-methylimidazole acetate is fed from the fifth theoretical plate of the rectification tower, the operating pressure is 101.3kPa, the solvent ratio is 1, and the reflux ratio is 4.0 . The operating pressure of the recovery tower is 85kPa. The output at the top of the rectification tower is 268.1kg / hr, the composition: ethanol 99.90%, water 0.10%, ethanol yield 99.2%. The extraction agent is extracted from the bottom of the recovery tower, with a water content of 0.15%, and returned to the rectification tower for recycling.

Embodiment 2

[0034] According to attached figure 1 As shown in the process flow, there are 25 theoretical plates in the rectifying tower, the raw material contains 49% ethanol and 51% water, and the material is fed from the 15th theoretical plate of the rectifying tower at a flow rate of 1000kg / hr, and the extractant is 1-butyl-3- Methylimidazole tetrafluoroborate is fed from the third theoretical plate of the rectification column, the operating pressure is 80kPa, the solvent ratio is 0.8, and the reflux ratio is 2.0. The operating pressure of the recovery tower is 75kPa. The output at the top of the rectification tower is 487.0kg / hr, the composition: ethanol 99.92%, water 0.08%, ethanol yield 99.3%. The extraction agent is extracted from the bottom of the recovery tower with a water content of 0.13%, and returned to the rectification tower for recycling.

Embodiment 3

[0036] According to attached figure 1 As shown in the process flow, there are 40 theoretical plates in the rectification tower, the raw material contains 65% ethanol and 35% water, and the material is fed from the 35th theoretical plate of the rectification tower at a flow rate of 1200kg / hr, and the extraction agent is 1-ethyl-3 -Methylimidazolium tetrafluoroborate and 1-octyl-3-methylimidazolium tetrafluoroborate with a volume ratio of 1:1 composite extractant, feed from the second theoretical plate of the rectification tower, operate The pressure is 65kPa, the solvent ratio is 0.5, and the reflux ratio is 0.5. The operating pressure of the recovery tower is 60kPa. The output at the top of the rectification tower is 778.0kg / hr, the composition: ethanol 99.95%, water 0.05%, ethanol yield 99.7%. The extraction agent is extracted from the bottom of the recovery tower with a water content of 0.10%, and returned to the rectification tower for recycling.