CN109851499B - Method and device for separating benzene from vinyl acetate by azeotropic distillation - Google Patents
Method and device for separating benzene from vinyl acetate by azeotropic distillation Download PDFInfo
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Abstract
The invention discloses a method and a device for separating benzene from vinyl acetate by azeotropic distillation. Any one or a mixture of more of methanol, water, ethanol, propanol and butanol is used as an entrainer, and benzene in vinyl acetate is separated through azeotropic rectification; the benzene content in the vinyl acetate is reduced to below 1 ppm. The device for separating the benzene in the vinyl acetate by using the azeotropic distillation mainly comprises an azeotropic distillation tower, a purification tower, an azeotropic distillation tower top condenser, an azeotropic distillation tower top reflux tank, an azeotropic distillation tower top reflux pump, an azeotropic distillation tower reboiler, an azeotropic distillation tower kettle liquid pump, a purification tower top condenser, a purification tower top aftercooler, a purification tower top phase splitting tank, a purification tower top reflux pump, a purification tower reboiler and a purification tower kettle liquid pump. The separation system has a simple structure, the related separation towers are normal pressure towers, the operation cost is low, and the separation system is safe and environment-friendly. The method is efficient and energy-saving, and can effectively remove the benzene impurity from trace to constant level.
Description
Technical Field
The invention relates to the technical field of chemical azeotropic distillation separation, in particular to a method and a device for separating benzene from vinyl acetate by azeotropic distillation.
Background
Vinyl Acetate (VAC), also known as vinyl acetate, is one of the largest organic chemical products in the world, and can be polymerized by itself or copolymerized with other monomers to produce polymers such as polyvinyl alcohol (PVA), vinyl acetate-ethylene copolymer (EVA), polyvinyl acetate (PVAC), vinyl acetate-vinyl chloride copolymer (EVC), and the like. The products have wide application, can be generally used for adhesives, sizing agents for paper or fabrics, paints, inks, leather processing, emulsifiers, water-soluble films, soil conditioners and the like, and are widely used in the fields of chemical industry, textile industry, light industry, papermaking, construction, automobiles and the like.
Under the energy pattern of lean oil, less gas and more coal in China, the process for producing vinyl acetate by the acetylene method based on the coal raw material has great advantages in China, but due to the process characteristics, the vinyl acetate product synthesized by the acetylene method contains benzene as an impurity. The existence of the impurity benzene can limit the subsequent product conversion and utilization of the vinyl acetate, and particularly influences the downstream products of the vinyl acetate to enter medical and food markets. The traditional rectification method can not effectively remove the benzene impurity in the vinyl acetate, so that the development of a method for separating the benzene in the vinyl acetate is urgently needed.
Patent CN 105418423A discloses a method and a device for debenzolizing and purifying n-propyl acetate. The method mixes the product of the benzene-containing n-propyl acetate with water, removes the light components containing benzene in a lightness-removing tower, and extracts the product from the tower kettle. The separation products of n-propyl acetate and benzene involved in the method have large boiling point difference and small separation difficulty; in addition, the method does not consider the subsequent separation and regeneration of the entrainer in the separation process, so that large raw material and energy waste exists; in addition, the benzene content in the separation raw material of the method is high, the aim of separating trace benzene cannot be achieved, and the benzene content in the obtained product cannot be lower than 1 ppm.
Patent CN 106187771a discloses a method for extracting and separating trace benzene in vinyl acetate by using alkane as an extracting agent. The method uses one or more mixtures of alkanes with 10-18 carbon atoms as an extracting agent, and separates trace benzene in vinyl acetate through extraction and rectification. Although the method can meet the separation requirement, one or more alkanes are introduced into the material as an extracting agent in the separation process, and new foreign impurities are introduced into the raw material stream, so that the impurity components in the product are more complicated. Meanwhile, the method requires a large amount of the extractant, and the production cost of the product is increased by considering the high cost and large loss of the extractant. In addition, the regeneration tower in the separation system adopts the vacuum rectification operation, so that the equipment investment and the operation cost are increased.
Therefore, a method with low removal cost, simple flow and good removal effect is needed to be found for removing the impurity benzene in the vinyl acetate.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a separation method for removing benzene in vinyl acetate by using one or more mixtures of methanol, water, ethanol, propanol and butanol as an entrainer, wherein the method can reduce the benzene content in the target product vinyl acetate to below 1 ppm. The invention also aims to provide a separation device for separating trace benzene in vinyl acetate by using one or more of methanol, water, ethanol, propanol and butanol as an azeotropic agent, and the system is suitable for the method.
The first technical scheme of the invention is as follows: a process for separating benzene from vinyl acetate by azeotropic rectification features that the mixture of methanol, water, alcohol, propanol and butanol is used as azeotropic agent, and the azeotropic rectification is used to separate benzene from vinyl acetate.
The invention specifically comprises the following steps:
1) one or more mixtures of vinyl acetate containing benzene and methanol, water, ethanol, propanol or butanol are taken as an entrainer and enter the azeotropic distillation tower from the lower part of the azeotropic distillation tower;
2) after azeotropic separation, one part of the azeotrope formed by benzene and the entrainer is extracted from the tower top, the other part of the azeotrope is uniformly mixed with the entrainer of one or more of methanol, water, ethanol, propanol and butanol which are added twice, then a polymerization inhibitor is added, the mixture flows back to the tower top, and a vinyl acetate product without benzene is extracted from the tower bottom of the azeotropic distillation tower;
3) the vinyl acetate product without benzene in the step 2) enters a purification tower for purification;
4) rectifying and purifying the mixture by a purifying tower, and collecting a vinyl acetate product from the side line at the lower part of the tower;
5) obtaining vinyl acetate containing light component impurities at the top of the purifying tower, separating oil from water, refluxing a water phase to the top of the azeotropic distillation tower, refluxing one part of an oil phase to the top of the purifying tower, and refluxing the other part of the oil phase to the lower part of the azeotropic distillation tower to be used as a feed for cyclic azeotropic separation again;
6) and (4) discharging impurities from the tower bottom liquid of the purification tower in a boundary region.
When the invention is used for the debenzolization and purification of the vinyl acetate, the benzene content in the finally obtained vinyl acetate product is lower than 1 ppm.
The mass ratio of an entrainer consisting of one or more of methanol, water, ethanol, propanol and butanol added from the top of the tower in the step 2) to the vinyl acetate containing benzene in the step 1) is 1: 100-1: 10.
In the step 1), the mass ratio of an entrainer consisting of one or more of methanol, water, ethanol, propanol and butanol to vinyl acetate containing benzene is 1: 100-1: 10.
The operation pressure of the azeotropic distillation tower in the step 1) is normal pressure, the temperature of the top of the tower is 50-65 ℃, and the temperature of the bottom of the tower is 68-75 ℃.
The operation pressure of the purification tower in the step 3) is normal pressure, the tower top temperature is 60-65 ℃, and the tower kettle temperature is 70-85 ℃.
The polymerization inhibitor in the step 2) is preferably hydroquinone.
The second technical scheme of the invention is as follows: the device for separating the benzene in the vinyl acetate by azeotropic distillation mainly comprises an azeotropic distillation tower, a purification tower, an azeotropic distillation tower top condenser, an azeotropic distillation tower top reflux tank, an azeotropic distillation tower top reflux pump, an azeotropic distillation tower reboiler, an azeotropic distillation tower kettle liquid pump, a purification tower top condenser, a purification tower top aftercooler, a purification tower top phase splitting tank, a purification tower top reflux pump, a purification tower reboiler and a purification tower kettle liquid pump; the azeotropic distillation tower is provided with a vinyl acetate feeding hole containing benzene, an entrainer feeding hole and an oil phase reflux liquid feeding hole of a phase separation tank at the top of the purification tower; the liquid outlet pump of the tower kettle of the azeotropic distillation tower is connected with the feed inlet of the purification tower; the outlet pipeline of the top reflux pump is connected with a pipeline for sending out vinyl acetate containing benzene impurities from a boundary region, and the outlet pipeline of the top reflux pump is connected with a reflux inlet at the top of the azeotropic distillation tower after being converged with a water phase outlet pipeline, a polymerization inhibitor inlet pipeline and an entrainer secondary adding pipeline at the top of a phase-splitting tank at the top of a purification tower; the liquid outlet of the azeotropic distillation tower kettle is connected with the inlet of the azeotropic distillation tower kettle liquid pump, and the outlet of the azeotropic distillation tower kettle liquid pump is connected with the feed inlet of the purification tower; the gas phase outlet of the top of the purification tower is connected with the inlet of the condenser at the top of the purification tower, the outlet of the condenser at the top of the purification tower is connected with the inlet of the post-cooler at the top of the purification tower, the outlet of the post-cooler at the top of the purification tower is connected with the inlet of the phase splitting tank at the top of the purification tower, the water phase outlet of the phase splitting tank at the top of the purification tower is connected with the reflux pipeline at the top of the azeotropic distillation tower, one oil phase outlet pipeline of the phase splitting tank at the top of the purification tower is connected with the feed inlet of the azeotropic distillation tower, and the other oil phase outlet pipeline is connected with the reflux inlet at the top of the purification tower.
The liquid discharged from the tower bottom of the purification tower is connected with a boundary outlet pipeline;
and a side extraction port at the lower part of the purification tower is connected with a vinyl acetate product pipeline.
The condenser at the top of the purification tower condenses the material at the top of the purification tower to 40-50 ℃, and the aftercooler at the top of the purification tower further cools the material to 25-35 ℃.
The invention has the following advantages and beneficial effects:
1. after separation of the azeotropic distillation tower and the purification tower, the benzene content in the final vinyl acetate product is less than 1PPm, and the benzene-free standard of food-grade materials is met;
2. the entrainer adopts one or more of methanol, water, ethanol, propanol and butanol as the entrainer, has simple composition and low cost, and can be recycled in the separation process;
3. the separation method has no limit on the benzene content in the fed vinyl acetate, and the impurity benzene from trace to constant level can be effectively removed;
4. the separation system has a simple structure, the related separation towers are normal pressure towers, the operation cost is low, and the separation system is safe and environment-friendly.
Drawings
FIG. 1 is a schematic flow chart of the device for separating benzene from vinyl acetate by azeotropic distillation according to the present invention.
Wherein: 101-azeotropic distillation column, 102-purification column, 103-azeotropic distillation column top condenser, 104-azeotropic distillation column top reflux tank, 105-azeotropic distillation column top reflux pump, 106-azeotropic distillation column reboiler, 107-azeotropic distillation column bottom liquid pump, 108-purification column top condenser, 109-purification column top aftercooler, 110-purification column top phase separation tank, 111-purification column top reflux pump, 112-purification column reboiler and 113-purification column bottom liquid pump.
Detailed Description
The present invention will now be described in further detail by way of examples with reference to the accompanying drawings, which are illustrative only and not limiting in nature, and the scope of the invention is not limited thereto.
The invention provides a method for separating benzene in vinyl acetate by azeotropic distillation, which adopts any one or a mixture of methanol, water, ethanol, propanol and butanol as an entrainer to separate the benzene in the vinyl acetate by azeotropic distillation. The method specifically comprises the following steps:
firstly, enabling benzene-containing vinyl acetate and an entrainer to respectively enter an azeotropic distillation tower from the lower part of the tower, wherein the mass ratio of the entrainer to the benzene-containing vinyl acetate is 1: 100-1: 10; the operating pressure of the azeotropic distillation tower is normal pressure, the temperature of the tower top is 50-65 ℃, and the temperature of the tower kettle is 68-75 ℃;
secondly, after azeotropic separation, a part of the azeotropic mixture formed by benzene and the entrainer is extracted from the top of the tower, the other part of the azeotropic mixture is mixed with one or more of methanol, water, ethanol, propanol and butanol which are added as the entrainer, hydroquinone is used as a polymerization inhibitor and then flows back to the top of the tower, and a vinyl acetate product without benzene is extracted from the bottom of the azeotropic distillation tower; the mass ratio of an entrainer consisting of any one or more of methanol, water, ethanol, propanol and butanol to vinyl acetate is 1: 100-1: 10; the benzene content in the finally obtained vinyl acetate product is lower than 1 ppm;
thirdly, outputting the vinyl acetate product without benzene to a purification tower for purification, wherein the operation pressure of the purification tower is normal pressure, the temperature of the top of the tower is 60-65 ℃, and the temperature of the bottom of the tower is 70-85 ℃;
fourthly, rectifying and purifying the mixture by a purifying tower, and collecting a vinyl acetate product from the side line at the lower part of the tower;
fifthly, obtaining vinyl acetate containing light component impurities at the top of the purifying tower, separating oil from water, refluxing a water phase to the top of the azeotropic distillation tower, refluxing one part of an oil phase to the top of the purifying tower, and refluxing the other part of the oil phase to the lower part of the azeotropic distillation tower to be used as a feed for cyclic azeotropic separation again;
and finally, extracting the tower bottom liquid of the purifying tower from a boundary region to remove impurities.
A device for realizing the method for separating benzene from vinyl acetate by azeotropic distillation, as shown in fig. 1, mainly comprising an azeotropic distillation tower 101, a purification tower 102, an azeotropic distillation tower top condenser 103, an azeotropic distillation tower top reflux tank 104, an azeotropic distillation tower top reflux pump 105, an azeotropic distillation tower reboiler 106, an azeotropic distillation tower kettle liquid pump 107, a purification tower top condenser 108, a purification tower top aftercooler 109, a purification tower top phase separation tank 110, a purification tower top reflux pump 111, a purification tower reboiler 112, and a purification tower kettle liquid pump 113;
the azeotropic distillation tower 101 is provided with a vinyl acetate feed inlet containing benzene, an entrainer feed inlet and an oil phase reflux feed inlet of the phase separation tank 110 at the top of the purification tower;
a liquid outlet pump at the bottom of the azeotropic distillation tower 101 is connected with a feed inlet of the purification tower 102;
the kettle of the azeotropic distillation tower 101 is provided with an azeotropic distillation tower reboiler 106;
the operating pressure of the azeotropic distillation tower 101 is normal pressure, the temperature of the top of the tower is 50-65 ℃, and the temperature of the bottom of the tower is 68-75 ℃;
a gas phase outlet at the top of the azeotropic distillation tower 101 is condensed by a condenser 103 at the top of the azeotropic distillation tower, condensate flows into a reflux tank 104 at the top of the azeotropic distillation tower, and the discharge of the reflux tank 104 at the top of the azeotropic distillation tower is converged by a part of pumped liquid, a water phase outlet pipeline of a phase separation tank 110 at the top of the purification tower, a polymerization inhibitor feeding pipeline and an entrainer feeding pipeline through a reflux pump 105 at the top of the azeotropic distillation tower, and then the part of pumped liquid is pumped back to the top of the azeotropic distillation tower 101, and the other part of pumped liquid is discharged;
the gas phase outlet at the top of the purifying tower 102 sequentially passes through a condenser 108 at the top of the purifying tower and a post-cooler 109 at the top of the purifying tower for condensation, the condensate flows into a phase separation tank 110 at the top of the purifying tower for oil-water separation, the oil phase in the phase separation tank 110 at the top of the purifying tower passes through a reflux pump 111 at the top of the purifying tower, part of pumped liquid is refluxed to the top of the purifying tower 102, and the other part of pumped liquid is sent to the inlet of the azeotropic distillation tower 101;
the condenser 108 at the top of the purification tower condenses the material at the top of the purification tower 102 to 40-50 ℃, and the aftercooler 109 at the top of the purification tower further cools the material to 25-35 ℃;
the tower outlet liquid of the purifying tower 102 is connected with an out-of-range pipeline;
a tower kettle of the purifying tower 102 is provided with a purifying tower reboiler 112;
the operating pressure of the purifying tower 102 is normal pressure, the temperature of the top of the tower is 60-65 ℃, and the temperature of the bottom of the tower is 70-85 ℃;
the side extraction port at the lower part of the purifying tower 102 is connected with a vinyl acetate product pipeline.
Example 1:
in this example, a process for separating benzene from vinyl acetate by azeotropic distillation was carried out using a conventional production apparatus having a structure shown in FIG. 1.
The vinyl acetate containing impurity benzene enters an azeotropic distillation tower (101) from the lower part, the feeding amount is 5500kg/hr, wherein the purity of the vinyl acetate is 99.96 wt%, and the benzene content is 300 ppm.
The mixture of methanol, butanol and water as entrainer enters an azeotropic distillation tower (101) from the lower part, and the feeding amount is 83 kg/hr; the azeotropic distillation tower (101) is operated under normal pressure, the temperature of the top of the tower is 53.4 ℃, and the temperature of the bottom of the tower is 69.8 ℃.
After azeotropic separation, one part of the azeotrope formed by the benzene and the entrainer is extracted from the top of the tower, the other part of the azeotrope is mixed with the mixture of methanol, water and butanol which are added twice, the feeding amount of the entrainer added twice is 536kg/hr, then hydroquinone is added as a polymerization inhibitor, the feeding amount of the hydroquinone is 10kg/hr, and the mixed stream is returned to the top of the azeotropic distillation tower (101). The mixture of the styrene acetate containing no benzene and the entrainer is obtained from the bottom of the azeotropic distillation tower (101) and is sent to a purification tower (102) for further purification.
The purification column (102) was operated at atmospheric pressure with a top temperature of 61.0 ℃ and a bottom temperature of 75.5 ℃. The azeotropic agent and a small amount of vinyl acetate are obtained from the top of the purification tower (102), and are firstly condensed to 50 ℃ by a tower top condenser (108), then condensed to 35 ℃ by a aftercooler (109), enter a phase-splitting tank (110) for phase splitting, the water phase returns to the top of the azeotropic distillation tower (101) for reflux, the oil phase returns to the top of the purification tower (102) for reflux, and the part returns to the azeotropic distillation tower (101) for recycling the feed.
Vinyl acetate containing impurities such as recombinant substances is obtained at the bottom of the purifying tower (102) and is discharged from a boundary area for impurity removal.
A high-purity vinyl acetate product is obtained by side line extraction at the lower part of the purification tower (102).
After the treatment of the process and the device, the benzene content in the finally obtained vinyl acetate product is 0.83ppm, the purity of the vinyl acetate is 99.99 percent, and the aim of benzene removal is achieved.
Example 2:
as shown in FIG. 1, the separation apparatus is such that the ethylene acetate containing benzene as an impurity is fed into an azeotropic distillation column (101) from the lower part thereof at a feed rate of 42000kg/hr, wherein the purity of the ethylene acetate is 98.82 wt% and the benzene content is 1500 PPm.
The entrainer water enters the azeotropic distillation tower (101) from the lower part, and the feeding amount is 418 kg/hr. The azeotropic distillation tower (101) is operated under normal pressure, the temperature of the top of the tower is 50.5 ℃, and the temperature of the bottom of the tower is 70.3 ℃.
After azeotropic separation, one part of the azeotropic mixture formed by the benzene and the entrainer is extracted from the top of the tower, the other part of the azeotropic mixture is mixed with the mixture of propanol and butanol which are the entrainer added for the second time, the feeding amount of the entrainer added for the second time is 46kg/hr, hydroquinone is added as a polymerization inhibitor after mixing, the feeding amount of the hydroquinone is 10kg/hr, and the combined stream returns to the top of the azeotropic distillation tower (101). The mixture of the styrene acetate containing no benzene and the entrainer is obtained from the bottom of the azeotropic distillation tower (101) and is sent to a purification tower (102) for further purification.
The purification column (102) was operated at atmospheric pressure with a top temperature of 63.3 ℃ and a bottom temperature of 77.7 ℃. The azeotropic agent and a small amount of vinyl acetate are obtained from the top of the purification tower (102), condensed to 45 ℃ through a tower top condenser (108), condensed to 30 ℃ through a aftercooler (109), and then enter a phase splitting tank (110) for phase splitting, a water phase returns to the top of the azeotropic distillation tower (101) for reflux, an oil phase returns to the top of the purification tower (102) for reflux, and a part returns to the azeotropic distillation tower (101) for recycling the feed.
Vinyl acetate containing impurities such as recombinant substances is obtained at the bottom of the purifying tower (102) and is discharged from a boundary area for impurity removal.
A high-purity vinyl acetate product is obtained by side line extraction at the lower part of the purification tower (102).
After the treatment of the process and the device, the benzene content in the finally obtained vinyl acetate product is 0.97ppm, the purity of the vinyl acetate is 99.99 percent, and the aim of benzene removal is achieved.
Example 3:
as shown in FIG. 1, the separation apparatus is such that the ethylene acetate containing benzene as an impurity is fed into an azeotropic distillation column (101) from the lower part, and the feeding amount is 50000kg/hr, wherein the purity of the ethylene acetate is 99.07 wt%, and the benzene content is 700 PPm.
The entrainer methanol, water and ethanol enter an azeotropic distillation tower (101) from the lower part, and the feeding amount is 360 kg/hr. The azeotropic distillation tower (101) is operated under normal pressure, the temperature of the top of the tower is 64.8 ℃, and the temperature of the bottom of the tower is 74.7 ℃.
After azeotropic separation, one part of the azeotrope formed by the benzene and the entrainer is extracted from the top of the tower, the other part of the azeotrope is mixed with the mixture of propanol and butanol which are the entrainer added for the second time, the feeding amount of the entrainer added for the second time is 420kg/hr, then hydroquinone is added as a polymerization inhibitor, the feeding amount of the hydroquinone is 10kg/hr, and the mixed stream returns to the top of the azeotropic distillation tower (101). The mixture of the styrene acetate containing no benzene and the entrainer is obtained from the bottom of the azeotropic distillation tower (101) and is sent to a purification tower (102) for further purification.
The purification column (102) was operated at atmospheric pressure with a top temperature of 64.9 ℃ and a bottom temperature of 83.9 ℃. The azeotropic agent and a small amount of vinyl acetate are obtained from the top of the purification tower (102), condensed to 40 ℃ by a tower top condenser (108), condensed to 25 ℃ by a aftercooler (109), and then enter a phase splitting tank (110) for phase splitting, the water phase returns to the top of the azeotropic distillation tower (101) for reflux, the oil phase returns to the top of the purification tower (102) for reflux, and the oil phase returns to the azeotropic distillation tower (101) for recycling the feed.
Vinyl acetate containing impurities such as recombinant substances is obtained at the bottom of the purifying tower (102) and is discharged from a boundary area for impurity removal.
A high-purity vinyl acetate product is obtained by side line extraction at the lower part of the purification tower (102).
After the treatment of the process and the device, the benzene content in the finally obtained vinyl acetate product is 0.74ppm, the purity of the vinyl acetate is 99.99 percent, and the aim of benzene removal is achieved.
Although the method and apparatus of the present invention have been described in terms of preferred embodiments, it will be apparent to those skilled in the art that modifications and rearrangements of the method and apparatus described herein can be made without departing from the spirit and scope of the invention to achieve the desired end result. It is expressly intended that all such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and content of the invention.
Claims (6)
1. A method for separating benzene in vinyl acetate by azeotropic distillation is characterized in that a mixture of methanol, butanol and water or a mixture of water and propanol and butanol which are added twice or a mixture of methanol, water and ethanol and propanol and butanol which are added twice is used as an azeotropic agent, and the benzene in the vinyl acetate is separated by azeotropic distillation, and the method comprises the following steps:
1) vinyl acetate containing benzene, a mixture of methanol, butanol and water or a mixture of water or methanol, water and ethanol as an entrainer enter the azeotropic distillation tower from the lower part of the azeotropic distillation tower;
2) after azeotropic separation, one part of the azeotrope formed by benzene and the entrainer is extracted from the top of the tower, the other part of the azeotrope is uniformly mixed with the entrainer of the mixture of methanol, butanol and water or the mixture of propanol and butanol which is added twice, then a polymerization inhibitor is added, the mixture flows back to the top of the tower, and a vinyl acetate product without benzene is extracted from the bottom of the azeotropic distillation tower;
3) the vinyl acetate product without benzene in the step 2) enters a purification tower for purification;
4) rectifying and purifying the mixture by a purifying tower, and collecting a vinyl acetate product from the side line at the lower part of the tower;
5) obtaining vinyl acetate containing light component impurities at the top of the purifying tower, separating oil from water, refluxing a water phase to the top of the azeotropic distillation tower, refluxing one part of an oil phase to the top of the purifying tower, and refluxing the other part of the oil phase to the lower part of the azeotropic distillation tower to be used as a feed for cyclic azeotropic separation again;
6) and (4) discharging impurities from the tower bottom liquid of the purification tower in a boundary region.
2. The method according to claim 1, wherein the mass ratio of the azeotropic agent introduced into the top of the column in the step 2) to the vinyl acetate containing benzene in the step 1) is 1:100 to 1: 10.
3. The method according to claim 1, wherein the mass ratio of the entrainer to the styrene-containing vinyl acetate in the step 1) is 1:100 to 1: 10.
4. The method as set forth in claim 1, wherein the azeotropic distillation tower in the step 1) is operated at normal pressure, the temperature at the top of the tower is 50-65 ℃ and the temperature at the bottom of the tower is 68-75 ℃.
5. The method as set forth in claim 1, wherein the operation pressure of the purification column in the step 3) is atmospheric pressure, the temperature of the top of the column is 60 to 65 ℃ and the temperature of the bottom of the column is 70 to 85 ℃.
6. The method as set forth in claim 1, characterized in that the polymerization inhibitor in the step 2) is hydroquinone.
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| CN111208239B (en) * | 2020-02-25 | 2022-10-18 | 浙江工业大学 | Impurity removal and purification method of bonded-state aroma substance |
| CN113563188A (en) * | 2021-08-06 | 2021-10-29 | 联泓新材料科技股份有限公司 | Method for recovering vinyl acetate from vinyl acetate waste liquid |
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| ES419805A1 (en) * | 1972-10-25 | 1976-07-16 | Hoechst Ag | Separation of mixtures of vinyl acetate and methanol containing minor amounts of methyl acetate and acetaldehyde by extraction distillation with an aromatic hydrocarbon |
| GB0200021D0 (en) * | 2002-01-02 | 2002-02-13 | Bp Chem Int Ltd | Process |
| CN100469755C (en) * | 2006-08-11 | 2009-03-18 | 河北工业大学 | Azeotropic distillation process for separating butanol and butyl acetate |
| CN101234947B (en) * | 2008-02-15 | 2012-05-23 | 南京大学 | Method for removing micro-benzene in solvent oil or hexane refining process |
| CN103086823B (en) * | 2013-02-07 | 2015-07-01 | 天津大学 | Method and device for separating n-hexane, isohexane and benzene |
| CN103772185B (en) * | 2014-02-07 | 2015-06-03 | 烟台国邦化工机械科技有限公司 | Device and method for removing moisture and heteroacids in acetic acid |
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| CN106631684B (en) * | 2015-10-31 | 2019-07-16 | 湖南中创化工股份有限公司 | A method of sec-butyl alcohol is prepared with sec-butyl acetate hydrolysis |
| CN105418423A (en) * | 2015-12-21 | 2016-03-23 | 南京荣欣化工有限公司 | Method and device for benzene-removal and purification of n-propyl acetate |
| CN205382109U (en) * | 2015-12-21 | 2016-07-13 | 南京荣欣化工有限公司 | Acetic acid n propyl ester takes off benzene purification device |
| CN107011169B (en) * | 2017-04-25 | 2018-07-10 | 天津大学 | A kind of process for purification and device of the vinyl acetate of acetylene method synthesis |
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