CN114702368A - Method for separating tertiary butanol-ethanol-water ternary azeotropic system by double-tower reactive extraction side-stream rectification process - Google Patents
Method for separating tertiary butanol-ethanol-water ternary azeotropic system by double-tower reactive extraction side-stream rectification process Download PDFInfo
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- C07C29/10—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom not belonging to a six-membered aromatic ring by hydrolysis of ethers, including cyclic ethers, e.g. oxiranes
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- C07C29/74—Separation; Purification; Use of additives, e.g. for stabilisation
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Abstract
The invention provides a method for separating a tertiary butanol-ethanol-water ternary azeotropic system by a double-tower reactive extraction side-stream rectification process, which is characterized by comprising the following steps of: ethylene oxide is adopted as a reaction solvent to react with water to generate a byproduct ethylene glycol, and the ethylene glycol is simultaneously adopted as an extraction solvent to realize the separation and purification of tertiary butanol-ethanol-water ternary azeotropic mixed liquor in a side-stream rectifying tower and a solvent recovery tower; the method can obtain the products of ethanol, glycol and tert-butyl alcohol, and has high purity and good separation effect. The energy consumption cost can be reduced by 30-60%. Reasonable operation, strong practicability and extremely high industrial popularization.
Description
Technical Field
The invention relates to the field of separation of multicomponent azeotrope, in particular to a method for separating a tertiary butanol-ethanol-water ternary azeotropic system by a double-tower reactive extraction side-stream rectification process.
Background
Tert-butyl alcohol and ethanol are important chemical raw materials. Tert-butanol is a colorless crystal with a camphor odor and is liquid in the presence of a small amount of water. It is used as solvent for paint and medicine, and as fuel additive for internal combustion engine to prevent carburetor from icing and antiknock agent. As an intermediate for organic synthesis and an alkylation raw material for producing a tert-butyl compound, methyl methacrylate, tert-butyl phenol, tert-butylamine and the like can be produced and used for synthesizing medicaments and spices. The isobutene with the purity of 99.0 to 99.9 percent can be prepared by dehydrating the tertiary butanol. The ethanol is flammable and volatile colorless transparent liquid at normal temperature and normal pressure, has low toxicity, and can not be directly drunk as pure liquid; has special fragrance and slight irritation; slightly sweet and accompanied by pungent and spicy taste. Inflammable, its steam can form explosive mixture with air, and it can be dissolved in water in any ratio. Can be mixed with chloroform, diethyl ether, methanol, acetone and other organic solvents, and has a relative density of 0.816. The ethanol has wide application range, and can be used for preparing acetic acid, beverages, essence, dye, fuel and the like. In medical treatment, ethanol with the volume fraction of 70-75% is also commonly used as a disinfectant and the like, and has wide application in national defense chemical industry, medical treatment and health, food industry, industrial and agricultural production.
Aqueous solution of tert-butyl alcohol and ethanol is often formed in the production process of the actual chemical industry and the pharmaceutical industry. If the waste water is directly discharged, environmental pollution and resource waste are caused, so that the waste water has a great prospect of recycling the waste water. Under normal pressure, the tert-butyl alcohol and the ethanol form azeotropy with water, and the tert-butyl alcohol and the ethanol cannot be separated by adopting common rectification and are difficult to separate. And the traditional rectification has high energy consumption, low energy utilization rate and large carbon dioxide emission, so special rectification is required. How to separate the mixed solution of tertiary butanol, ethanol and water with energy conservation and high efficiency becomes a problem which needs to be solved urgently.
CN109678668 discloses a method for separating ethanol-tert-butanol-water by rectification, which comprises the steps of carrying out pre-dehydration treatment, azeotropic treatment, steam stripping treatment and rectification treatment on raw materials containing ethanol, tert-butanol and water, and then separating the ethanol and the tert-butanol to obtain products of ethanol and tert-butanol; and an entrainer is added in the azeotropic treatment stage and is used for removing water in the residual materials. The method has complex treatment process and high cost.
Disclosure of Invention
The invention aims to at least solve the technical problems in the prior art, and particularly provides a method for separating a tertiary butanol-ethanol-water ternary azeotropic system by a double-tower reactive extraction side-stream rectification process, which has the advantages of simple operation, low energy consumption and low cost.
In order to achieve the aim, the invention provides a method for separating a tertiary butanol-ethanol-water ternary azeotropic system by a double-tower reactive extraction side-stream rectification process, which is characterized by comprising the following steps of: ethylene oxide is adopted as a reaction solvent to react with water to generate a byproduct ethylene glycol, and the ethylene glycol is simultaneously adopted as an extraction solvent to realize the separation and purification of tertiary butanol-ethanol-water ternary azeotropic mixed liquor in a side-stream rectifying tower and a solvent recovery tower;
the side-line rectifying tower is internally divided into a rectifying section, a reaction section, an extraction section and a stripping section from top to bottom in sequence, the solvent recovery tower is internally divided into the rectifying section and the stripping section from top to bottom in sequence,
the upper part of the side rectifying tower is provided with an extraction solvent inlet, the lower part of the side rectifying tower is provided with a reaction solvent inlet, the middle part of the side rectifying tower is provided with a mixed solution inlet, and the extraction solvent ethylene glycol, the reaction solvent ethylene oxide, the tertiary butanol-ethanol-water ternary azeotropic mixed solution respectively enter from the extraction solvent inlet, the reaction solvent inlet and the mixed solution inlet; ethanol is extracted from the top of the side-stream rectifying tower; and a liquid phase outlet at the lower part of the lateral line rectifying tower is connected with a feed inlet of the solvent recovery tower, tertiary butanol is extracted from the top of the solvent recovery tower, liquid at the tower bottom of the solvent recovery tower flows into a second reboiler, after the liquid is heated by the second reboiler, one part of the liquid flows back to the tower bottom of the solvent recovery tower, and the other part of the liquid is cooled by an extraction solvent condenser to obtain the ethylene glycol. And (3) extracting a part of the cooled product ethylene glycol, and using a part of the ethylene glycol as an extraction solvent.
The invention utilizes the reaction of reaction solvent ethylene oxide and water, and the added reaction solvent ethylene oxide can quickly react with the water in the feeding tert-butyl alcohol-ethanol-water azeotropic mixed solution to generate the byproduct ethylene glycolAnd then, by utilizing the characteristic that the different molecular acting forces of the byproduct ethylene glycol on the residual components of the tert-butyl alcohol and the ethanol are utilized, and a certain amount of ethylene glycol is additionally added to increase the relative volatility of the components to be separated of the tert-butyl alcohol and the ethanol, the separation and purification of the ternary azeotropic mixture are realized by adopting a reaction coupling extraction rectification process. The method can effectively improve thermodynamic efficiency, thereby increasing relative volatility, reducing heat load, ensuring product quality, reducing production cost and CO2The process flow is reduced, and the safety of the process is improved. The purity of the separated tertiary butanol is more than 99.5%, the purity of the ethanol is more than 99.5%, and the purity of the circulating extraction solvent glycol is more than 99.99%.
In the scheme, the method comprises the following steps: an ethanol extraction line is arranged at the top of the lateral line rectifying tower and connected with an ethanol condenser, the ethanol condenser is connected with an ethanol reflux tank, an ethanol reflux pipe is arranged on the ethanol reflux tank and connected with a top reflux port of the lateral line rectifying tower, and an ethanol extraction line is further arranged on the ethanol reflux tank.
In the scheme, the method comprises the following steps: and the tower bottom liquid of the side-line rectifying tower flows into the first reboiler, after being heated by the first reboiler, one part of the tower bottom liquid flows back to the side-line rectifying tower, and the other part of the tower bottom liquid is extracted. The produced liquid is glycol. The invention can extract glycol from the bottoms of both the solvent recovery tower and the side-stream rectifying tower.
In the scheme, the method comprises the following steps: the feeding molar ratio of the reaction solvent to tertiary butanol-ethanol-water ternary azeotropic mixed liquor is 0.25-0.35; the feeding molar ratio of the extraction solvent to the tertiary butanol-ethanol-water ternary azeotropic mixed liquor is 1.8-2.2, and the feeding temperature of the tertiary butanol-ethanol-water ternary azeotropic mixed liquor is 45-55 ℃.
In the scheme, the method comprises the following steps: the number of theoretical plates of the side-stream rectifying tower is 48-52, an extraction solvent inlet is positioned at 3-5 plates from top to bottom, a reaction solvent inlet is positioned at 28-32 plates, a mixed solution inlet is positioned at 10-15 plates, the mixed solution inlet is positioned between the extraction solvent inlet and the reaction solvent inlet, a side-stream liquid phase outlet is positioned at 45-48 plates, the tower top temperature is 77-79 ℃, the tower bottom temperature is 205-207 ℃, the operating pressure is 1.01bar (absolute pressure), and the reaction section is positioned between 8-37 plates.
In the scheme, the method comprises the following steps: the feeding amounts of the extraction solvent ethylene glycol and the reaction solvent ethylene oxide are respectively 180-220kmol/h and 25-35kmol/h, and the feeding amount of the tertiary butanol-ethanol-water ternary azeotropic mixed liquid is 90-110 kmol/h.
In the scheme, the method comprises the following steps: the reflux ratio of the side rectifying tower is 1.5-3.0, and the liquid holdup of the tower plate is 0.15-0.25m3。
In the scheme, the method comprises the following steps: the liquid inlet flow of the solvent recovery tower is 210-230kmol/h, the theoretical plate number of the solvent recovery tower is 10-15, the feed inlet is positioned at the 5-7 th plate, the tower top temperature is 81-83 ℃, and the tower bottom temperature is 198-200 ℃.
In the scheme, the method comprises the following steps: the reflux ratio of the solvent recovery tower is 0.3-0.5, and the operating pressure is 1.01bar (absolute).
In the scheme, the method comprises the following steps: the top of the solvent recovery tower is provided with a tertiary butanol extraction line connected with a tertiary butanol condenser, the tertiary butanol condenser is connected with a tertiary butanol reflux tank, and part of the tertiary butanol in the tertiary butanol reflux tank is extracted and part of the tertiary butanol returns to the solvent recovery tower.
Has the advantages that: (1) the separation method of the invention has reasonable operation, strong practicability and extremely high industrial popularization. The reaction coupling extraction rectifying tower can effectively reduce the separation difficulty, and the obtained product has high purity.
(2) The energy consumption of the separation process is reduced. Compared with the three-tower extraction rectification, the reactive extraction side-stream rectification device related by the invention can reduce the energy consumption cost by 30-60%.
(3) Compared with the traditional process, the method of the invention has the advantages of short process flow, simple operation and improved safety performance.
(4) The method of the invention can effectively reduce
Loss and carbon dioxide emission, thereby realizing the concept of sustainable green development.
(5) The method can obtain the products of ethanol, glycol and tertiary butanol, and has high purity and good separation effect.
Drawings
FIG. 1 is a process flow diagram of the present invention.
Detailed Description
Example 1
As shown in fig. 1
The side-line rectifying tower 1 is internally divided into a rectifying section, a reaction section, an extraction section and a stripping section from top to bottom in sequence, and the solvent recovery tower 2 is internally divided into the rectifying section and the stripping section from top to bottom in sequence.
The upper part of the lateral line rectifying tower 1 is provided with an extraction solvent inlet 101, the lower part is provided with a reaction solvent inlet 103, the middle part is provided with a mixed liquid inlet 102, and the extraction solvent ethylene glycol, the reaction solvent ethylene oxide and the tertiary butanol-ethanol-water ternary azeotropic mixed liquid respectively enter from the extraction solvent inlet 101, the reaction solvent inlet 103 and the mixed liquid inlet 102. Ethanol is extracted from the top of the side rectification column 1. Specifically, an ethanol extraction line is arranged at the top of the lateral line rectifying tower 1 and connected with an ethanol condenser 3, the ethanol condenser 3 is connected with an ethanol reflux tank 4, an ethanol reflux pipe is arranged on the ethanol reflux tank 4 and connected with a top reflux port of the lateral line rectifying tower 1, and an ethanol extraction line is further arranged on the ethanol reflux tank 4.
The liquid in the tower bottom of the side rectification tower 1 flows into a first reboiler 5, after being heated by the first reboiler 5, one part of the liquid flows back to the bottom of the side rectification tower 1, and the other part of the liquid is extracted, wherein the extracted liquid is ethylene glycol.
The theoretical plate number of the side-line rectifying tower is 48-52, the extraction solvent inlet is positioned at 3-5 plates from top to bottom, the reaction solvent inlet is positioned at 28-32 plates, the mixed liquid inlet is positioned at 10-15 plates, the mixed liquid inlet is positioned between the extraction solvent inlet and the reaction solvent inlet, the side-line liquid phase outlet 104 is positioned at 45-48 plates, the tower top temperature is 77-79 ℃, the tower bottom temperature is 205-207 ℃, the operating pressure is 1.01bar (absolute pressure), and the reaction section is positioned between 8-37 plates. The reflux ratio of the side rectifying tower is 1.5-3.0, and the liquid holdup of the tower plate is 0.15-0.25m3。
The feeding molar ratio of the reaction solvent to the tertiary butanol-ethanol-water ternary azeotropic mixed liquid is 0.25-0.35; the feeding molar ratio of the extraction solvent to the tertiary butanol-ethanol-water ternary azeotropic mixed liquid is 1.8-2.2. The feeding amounts of the extraction solvent ethylene glycol and the reaction solvent ethylene oxide are respectively 180-220kmol/h and 25-35kmol/h, and the feeding amount of the tertiary butanol-ethanol-water ternary azeotropic mixed liquid is 90-110 kmol/h.
A side line liquid phase outlet 104 at the lower part of the side line rectifying tower 1 is connected with a feed inlet of the solvent recovery tower 2, tertiary butanol is extracted from the top of the solvent recovery tower 2, a tertiary butanol extraction line is arranged at the top of the solvent recovery tower 2 and is connected with a tertiary butanol condenser 6, the tertiary butanol condenser 6 is connected with a tertiary butanol reflux tank 7, part of the tertiary butanol in the tertiary butanol reflux tank 7 is extracted, and part of the tertiary butanol is refluxed to the solvent recovery tower 2.
The liquid in the bottom of the solvent recovery tower 2 flows into a second reboiler 8, after being heated by the second reboiler 8, one part of the liquid flows back to the bottom of the solvent recovery tower 2, the other part of the liquid is cooled by an extraction solvent condenser 9 to obtain ethylene glycol, and one part of the ethylene glycol is extracted and the other part of the ethylene glycol is used as an extraction solvent.
The liquid inlet flow of the solvent recovery tower 2 is 210-230kmol/h, the theoretical plate number of the solvent recovery tower 2 is 10-15, the feed inlet is positioned at the 5 th-7 th plate, the tower top temperature is 81-83 ℃, and the tower bottom temperature is 198-200 ℃. The reflux ratio of the solvent recovery column 2 is 0.3-0.5, and the operating pressure is 1.01bar (absolute).
Application example 1
The mixed solution of a certain chemical pharmaceutical enterprise is separated and then comprises the following components: 35% t-butanol, 35% ethanol, and 30% water.
The operating parameters of the side rectifying tower are as follows: the operating pressure is normal pressure (absolute pressure), the theoretical plate number is 50, the extraction solvent inlet is positioned at the 3 rd tower plate, the mixed liquid inlet is positioned at the 13 th tower plate, the reaction solvent inlet is positioned at the 30 th tower plate, the reflux ratio is 2.12, the reaction section in the lateral line rectifying tower is positioned between the 10 th tower plate and the 35 th tower plate, the lower lateral line liquid phase outlet 104 is positioned at the 48 tower plates, and the liquid holdup of the tower plates is 0.195m3The temperature at the top of the column was 77.8 ℃ and the temperature at the bottom of the column was 206.3 ℃. The temperature of the azeotropic mixed solution of the tertiary butanol, the ethanol and the water is 50 ℃, the flow rate is 100kmol/h, and the pressure is 1.0bar (absolute). The flow rate of the side mixed liquid (the feed liquid flow rate of the solvent recovery tower) was 220 kmol/h. The temperature of the ethylene oxide solution as reaction solvent was 30 ℃, the flow rate was 30kmol/h and the pressure was 1.0bar (absolute). The temperature of the extraction solvent, ethylene glycol solution, was 50 ℃, the flow was 212kmol/h and the pressure was 1.0bar (absolute).
Ethanol is extracted from the top of the side rectification tower, is cooled by an ethanol condenser 3 and then enters an ethanol reflux tank 4, part of ethanol is refluxed to the upper part of the side rectification tower, and the other part of ethanol is extracted.
The tower bottom liquid of the side rectification tower flows into the first reboiler 5, after being heated by the first reboiler 5, one part of the tower bottom liquid flows back to the side rectification tower, and the other part of the tower bottom liquid is extracted.
The side mixed liquid is extracted and sent to a solvent recovery tower.
The operating parameters of the solvent recovery tower are as follows: the operating pressure was 1.0bar (absolute), the number of theoretical plates was 11, the feed inlet of the solvent recovery column was located on the 6 th plate, the reflux ratio was 0.42, the overhead temperature was 82.1 ℃ and the bottom temperature was 198.9 ℃.
The tertiary butanol is extracted from the top of the solvent recovery tower, cooled by a tertiary butanol condenser 6 and then enters a tertiary butanol reflux tank 7, part of the tertiary butanol refluxes to the upper part of the solvent recovery tower, and the other part of the tertiary butanol is extracted.
And the tower bottom liquid from the solvent recovery tower flows into a second reboiler 7, after being heated by the reboiler 7, one part of the liquid flows back to the tower bottom of the solvent recovery tower, the other part of the liquid is sent to an extraction solvent cooler 9 for cooling, the cooled extraction solvent part is sent to an extraction solvent inlet of the side rectification tower to enter, and the other part of the liquid is directly extracted.
The purity of the separated tertiary butanol is more than 99.5%, the purity of the ethanol is more than 99.5%, and the purity of the circulating extraction solvent is more than 99.99%.
Application example 2
The mixed solution of a certain chemical pharmaceutical enterprise is separated to form the following components: 32.5% t-butanol, 32.5% ethanol, and 35% water.
The operating parameters of the side rectifying tower are as follows: the operating pressure is normal pressure (absolute pressure), and the theoretical plate number is48 extraction solvent inlets are positioned at the 4 th tower plate, tertiary butanol, ethanol and water azeotropic mixture inlets are positioned at the 10 th tower plate, reaction solvent inlets are positioned at the 28 th tower plate, the reflux ratio is 2.5, a reaction section in the lateral line rectifying tower is positioned between the 8 th tower plate and the 33 th tower plate, a lateral line liquid phase outlet 104 is positioned at the 45 th tower plate, and the liquid holdup of the tower plates is 0.22m3The temperature at the top of the column was 77.0 ℃ and the temperature at the bottom of the column was 205 ℃. The temperature of the azeotropic mixture solution of t-butanol, ethanol and water was 45 ℃, the flow rate was 100kmol/h, and the pressure was 1.0bar (absolute). The flow rate of the side mixed liquid (feed flow rate of the solvent recovery column 2) was 210 kmol/h. The temperature of the ethylene oxide solution as reaction solvent was 25 ℃, the flow rate was 35kmol/h and the pressure was 1.0bar (absolute). The temperature of the extraction solvent, ethylene glycol solution, was 45 ℃, the flow rate was 180kmol/h and the pressure was 1.0bar (absolute).
The operating parameters of the solvent recovery column were: the operating pressure was 1.0bar (absolute), the number of theoretical plates was 10, the feed inlet of the solvent recovery column was located on the 5 th plate, the reflux ratio was 0.3, the overhead temperature was 82.0 ℃ and the bottom temperature was 200 ℃.
The purity of the separated tertiary butanol is more than 99.5%, the purity of the ethanol is more than 99.5%, and the purity of the circulating extraction solvent is more than 99.99%.
Example 3:
the mixed solution of a certain chemical pharmaceutical enterprise is separated to form the following components: 37.5% t-butanol, 37.5% ethanol, and 25% water.
The operating parameters of the side rectifying tower are as follows: the operation pressure is normal pressure (absolute pressure), the number of theoretical plates is 52, an extraction solvent inlet is positioned at the 5 th tower plate, a tert-butyl alcohol, ethanol and water azeotropic mixture inlet is positioned at the 12 th tower plate, a reaction solvent inlet is positioned at the 32 th tower plate, the reflux ratio is 3.0, a reaction section in a lateral line rectifying tower is positioned between the 12 th tower plate and the 37 th tower plate, a lateral line mixed liquid extraction position is positioned at the 46 th tower plate, and the tower plate liquid holdup is 0.18m3The temperature at the top of the column was 79.0 ℃ and the temperature at the bottom of the column was 207 ℃. The temperature of the mixed solution of tert-butanol, ethanol and water was 45 ℃, the flow rate was 100kmol/h and the pressure was 1.0bar (absolute). The flow rate of the side line mixed liquid is 230kmol/h. The temperature of the ethylene oxide solution as reaction solvent was 35 ℃, the flow rate was 25kmol/h and the pressure was 1.0bar (absolute). The temperature of the extraction solvent, ethylene glycol solution, was 55 ℃, the flow rate was 220kmol/h and the pressure was 1.0bar (absolute).
The operating parameters of the solvent recovery column were: the operating pressure was 1.0bar (absolute), the theoretical plate number was 15, the feed inlet g of the solvent recovery column was located on the 7 th plate, the reflux ratio was 0.5, the overhead temperature was 83.0 ℃ and the bottom temperature was 198 ℃.
The purity of the separated tertiary butanol is more than 99.5%, the purity of the ethanol is more than 99.5%, and the purity of the circulating extraction solvent is more than 99.99%.
While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.
Claims (10)
1. A method for separating tertiary butanol-ethanol-water ternary azeotropic system by a double-tower reactive extraction side-stream rectification process is characterized by comprising the following steps: ethylene oxide is adopted as a reaction solvent to react with water to generate a byproduct ethylene glycol, and the ethylene glycol is simultaneously adopted as an extraction solvent to realize the separation and purification of tertiary butanol-ethanol-water ternary azeotropic mixed liquor in a side-stream rectifying tower and a solvent recovery tower;
the side-line rectifying tower is internally divided into a rectifying section, a reaction section, an extraction section and a stripping section from top to bottom in sequence, the solvent recovery tower is internally divided into the rectifying section and the stripping section from top to bottom in sequence,
the upper part of the side rectifying tower is provided with an extraction solvent inlet, the lower part of the side rectifying tower is provided with a reaction solvent inlet, the middle part of the side rectifying tower is provided with a mixed solution inlet, and the extraction solvent ethylene glycol, the reaction solvent ethylene oxide, the tertiary butanol-ethanol-water ternary azeotropic mixed solution respectively enter from the extraction solvent inlet, the reaction solvent inlet and the mixed solution inlet; ethanol is extracted from the top of the side-stream rectifying tower; and a liquid phase outlet at the lower side line of the side line rectifying tower is connected with a feed inlet of the solvent recovery tower, tertiary butanol is extracted from the top of the solvent recovery tower, liquid at the tower bottom of the solvent recovery tower flows into a second reboiler, one part of the liquid flows back to the tower bottom of the solvent recovery tower after being heated by the second reboiler, and the other part of the liquid is cooled by an extraction solvent condenser to obtain ethylene glycol.
2. The method for separating tertiary butanol-ethanol-water ternary azeotropic system by using the double-tower reactive extraction side-stream distillation process according to claim 1, which is characterized in that: an ethanol extraction line is arranged at the top of the lateral line rectifying tower and connected with an ethanol condenser, the ethanol condenser is connected with an ethanol reflux tank, an ethanol reflux pipe is arranged on the ethanol reflux tank and connected with a top reflux port of the lateral line rectifying tower, and an ethanol extraction line is further arranged on the ethanol reflux tank.
3. The method for separating tertiary butanol-ethanol-water ternary azeotropic system by using the double-tower reactive extraction side-stream distillation process according to claim 2, which is characterized in that: and the tower bottom liquid of the side-line rectifying tower flows into the first reboiler, after being heated by the first reboiler, one part of the tower bottom liquid flows back to the side-line rectifying tower, and the other part of the tower bottom liquid is extracted.
4. The method for separating tertiary butanol-ethanol-water ternary azeotropic system by the double-tower reactive extraction side-stream distillation process according to any one of claims 1 to 3, which is characterized in that: the feeding molar ratio of the reaction solvent to tertiary butanol-ethanol-water ternary azeotropic mixed liquor is 0.25-0.35; the feeding molar ratio of the extraction solvent to the tertiary butanol-ethanol-water ternary azeotropic mixed liquor is 1.8-2.2, and the feeding temperature of the tertiary butanol-ethanol-water ternary azeotropic mixed liquor is 45-55 ℃.
5. The method for separating tertiary butanol-ethanol-water ternary azeotropic system by using the double-tower reactive extraction side-stream distillation process according to claim 4, which is characterized in that: the number of theoretical plates of the side-stream rectifying tower is 48-52, an extraction solvent inlet is positioned at 3-5 plates from top to bottom, a reaction solvent inlet is positioned at 28-32 plates, a mixed solution inlet is positioned at 10-15 plates, the mixed solution inlet is positioned between the extraction solvent inlet and the reaction solvent inlet, a side-stream liquid phase outlet is positioned at 45-48 plates, the tower top temperature is 77-79 ℃, the tower bottom temperature is 205-207 ℃, the operating pressure is 1.01bar (absolute pressure), and the reaction section is positioned between 8-37 plates.
6. The method for separating the tertiary butanol-ethanol-water ternary azeotropic system by the double-tower reactive extraction side-stream distillation process according to claim 5, which is characterized in that: the feeding amounts of the extraction solvent ethylene glycol and the reaction solvent ethylene oxide are respectively 180-220kmol/h and 25-35kmol/h, and the feeding amount of the tertiary butanol-ethanol-water ternary azeotropic mixed liquid is 90-110 kmol/h.
7. The method for separating tertiary butanol-ethanol-water ternary azeotropic system by using the double-tower reactive extraction side-stream distillation process according to claim 6, which is characterized in that: the reflux ratio of the side rectifying tower is 1.5-3.0, and the liquid holdup of the tower plate is 0.15-0.25m3。
8. The method for separating tertiary butanol-ethanol-water ternary azeotropic system by using the double-tower reactive extraction side-stream distillation process according to claim 7, which is characterized in that: the liquid inlet flow of the solvent recovery tower is 210-230kmol/h, the theoretical plate number of the solvent recovery tower is 10-15, the feed inlet is positioned at the 5-7 th plate, the tower top temperature is 81-83 ℃, and the tower bottom temperature is 198-200 ℃.
9. The method for separating tertiary butanol-ethanol-water ternary azeotropic system by using the double-tower reactive extraction side-stream distillation process according to claim 8, which is characterized in that: the reflux ratio of the solvent recovery tower is 0.3-0.5, and the operating pressure is 1.01bar (absolute).
10. The method for separating tertiary butanol-ethanol-water ternary azeotropic system by the double-tower reactive extraction side-stream distillation process according to claim 9, which is characterized in that: the top of the solvent recovery tower is provided with a tertiary butanol extraction line connected with a tertiary butanol condenser, the tertiary butanol condenser is connected with a tertiary butanol reflux tank, and part of the tertiary butanol in the tertiary butanol reflux tank is extracted and part of the tertiary butanol returns to the solvent recovery tower.
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| CN202210401490.0A CN114702368A (en) | 2022-04-18 | 2022-04-18 | Method for separating tertiary butanol-ethanol-water ternary azeotropic system by double-tower reactive extraction side-stream rectification process |
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| CN202210401490.0A CN114702368A (en) | 2022-04-18 | 2022-04-18 | Method for separating tertiary butanol-ethanol-water ternary azeotropic system by double-tower reactive extraction side-stream rectification process |
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| CN115340443A (en) * | 2022-08-03 | 2022-11-15 | 青岛科技大学 | Method for separating isopropanol-water-ethanol mixture by thermal coupling extractive distillation |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115340443A (en) * | 2022-08-03 | 2022-11-15 | 青岛科技大学 | Method for separating isopropanol-water-ethanol mixture by thermal coupling extractive distillation |
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