CN112920049A

CN112920049A - Method and device for preparing tert-butyl acetate

Info

Publication number: CN112920049A
Application number: CN201911235574.6A
Authority: CN
Inventors: 王坤; 刘郁东; 肖云飞; 刘良会
Original assignee: Hunan Zhongchuang Chemical Co Ltd
Current assignee: Hunan Zhongchuang Chemical Co Ltd
Priority date: 2019-12-05
Filing date: 2019-12-05
Publication date: 2021-06-08
Anticipated expiration: 2039-12-05
Also published as: CN112920049B

Abstract

The invention relates to a method and a device for preparing tert-butyl acetate, which mainly comprises the steps of feeding a mixture of tert-butyl acetate, C8 and tert-butyl alcohol obtained from the top of a tert-butyl acetate refining tower into an extraction tower for extraction, extracting C8 and tert-butyl acetate from the top of the extraction tower, and extracting a mixture of tert-butyl alcohol and water from the bottom of the extraction tower; and (3) feeding a mixture of the tertiary butanol extracted from the bottom of the extraction tower and water into a rectifying tower for separation, extracting the tertiary butanol containing water from the top of the tower, and extracting the water from the bottom of the tower. The method provided by the invention successfully solves the problems of low recovery rate of tert-butyl acetate, more reaction byproducts and low recovery rate of tert-butyl alcohol in the prior art, can effectively inhibit side reactions, reduces byproducts after the reaction, simultaneously inhibits pyrolysis of tert-butyl acetate, and improves selectivity and yield of tert-butyl acetate. The method has the advantages of simple process, easy operation and low energy consumption.

Description

Method and device for preparing tert-butyl acetate

Technical Field

The invention relates to a method and a device for preparing tert-butyl acetate, in particular to a method and a device for preparing tert-butyl acetate by using acetic acid and isobutene or a mixed C4 containing isobutene.

Background

Tert-butyl acetate is a colorless liquid with a fruity flavor, belongs to a low-toxicity solvent, and is listed as exempting from limited volatile solvents and non-harmful air pollutants by the United states national environmental protection agency. Due to the unique molecular structure (large steric hindrance), the compatibility of the solvent can be greatly improved when the solvent is mixed with other solvents. Such as: nitrocellulose, acrylic, alkyd, polyester, and polyurethane resins, and the like. As the oxygen-containing solvent, it can produce synergistic effect with other solvents (toluene, trichloroethane, etc.). As an environment-friendly solvent, the method can obviously reduce the atmospheric photochemical reaction activity, the volatility at normal temperature and the content of harmful air pollutants of a target product. Can replace toluene, xylene, esters, ketones, hydrocarbons and the like. The product is mainly applied to the fields of coatings, printing ink, paint, adhesives, medical intermediates, industrial cleaning agents, electronic industry, agricultural products, textiles, gasoline shockproof additives, fuels and the like.

The current methods for producing tert-butyl acetate are: 1. acylation method: tert-butyl alcohol and acetic anhydride are used as raw materials, catalysts comprise zinc chloride, lithium perchlorate, ceric ammonium nitrate, pyridine, triethylamine, 4-Dimethylaminopyridine (DMAP), stannic chloride and the like, but the zinc chloride is easy to absorb moisture, organic amines have pungent odor and certain toxicity, the cost is high, the utilization rate of the acetic anhydride is not high, a large amount of acetic acid is contained in a product, and the industrial production is limited; 2. an acid chloride method: tert-butyl alcohol and acetyl chloride are used as raw materials, N-dimethylaniline and magnesium are used as catalysts, toxic substances are sensed in the raw materials and products, and the method is not applicable to the industry; 3. direct esterification of alkyd: tert-butyl alcohol and acetic acid are used as raw materials, and a catalyst is concentrated sulfuric acid, so that the requirement on equipment materials is high, and side reactions are more. The traditional production process of the tert-butyl acetate has long flow, complex process, higher cost, large sewage treatment capacity and serious environmental pollution; 4. acid alkene addition method: acetic acid and isobutene are used as raw materials, strong acid ion exchange resin is used as a catalyst, and tert-butyl acetate is synthesized in one step through direct addition esterification.

Acid alkene method: acetic acid and isobutene enter a fixed bed reactor to react under the action of an etherification catalyst, and materials after the reaction enter a separation system to refine the product. The reaction equation is as follows:

during the synthesis of tert-butyl acetate, the following side reactions also occur in small amounts:

chinese patent CN200610031938.5 discloses a method for preparing purified tert-butyl acetate, acetic acid and C4 containing isobutene are continuously added into an esterification tower filled with a strong acid type ion exchange resin catalyst, the molar ratio of the acetic acid to the isobutene is 1: 0.30-1: 5.00, esterification reaction is carried out under the conditions that the feeding airspeed of the acetic acid is 0.5-5.0 h < -1 >, the dosage of the catalyst is 30-90 ml, the pressure is 0.5-2.0 MPa, and the reaction temperature is 30-110 ℃ to obtain crude ester; feeding the crude ester into a separation tower, deacidifying at the top gas phase reflux temperature of 85-100 ℃, dealkylating at 70-85 ℃, dealcoholizing at 78-90 ℃, and finally rectifying at 90-100 ℃ to obtain a tert-butyl acetate product. The method adopts C4 rich in oil refineries as a raw material, can greatly reduce the production cost of products, and simultaneously solves the problem of energy consumption increase caused by water diversion difficulty in the traditional acid/alcohol process; realizes continuous esterification reaction and separation and purification, and the product content of the tert-butyl acetate can reach more than 99.5 percent.

The preparation method is characterized in that Chenzhonghua adopts an acid alkene method to synthesize tert-butyl acetate, acetic acid and isobutene are used as raw materials, an A15 catalyst is selected for research, and temperature and reaction time are examinedPressure, space velocity, acid-olefin molar ratio, and esterification reaction. Obtaining the appropriate reaction temperature of 17-20 ℃, the reaction time of 80-190min, the pressure of 0.8-1.2MPa and the space velocity of 3-5h^-1The molar ratio of the acid alkene is (4-5): 1. the study also examined the effect of adding water and tert-butanol to acetic acid on the esterification reaction, respectively, and the results show that the addition of a small amount of water and tert-butanol helps to improve the selectivity of tert-butyl acetate and inhibit the formation of oligomers. And the esterification effect of the method of adding tertiary butanol into acetic acid is better than that of the method of adding water. The proper addition amount of the tertiary butyl alcohol in the acetic acid is 6 percent, the selectivity of the tertiary butyl acetate can reach more than 95 percent, and the selectivity of the isobutene oligomer can be controlled to be less than 4.5 percent.

In order to reduce the generation of the by-product C8, tertiary butanol is added into the reaction material as a polymerization inhibitor to reduce the generation of C8, simultaneously, moisture contained in the raw material also reacts with isobutene to generate the tertiary butanol, and a certain amount of the tertiary butanol is contained in the material at the outlet of the reactor.

After the reaction materials are separated, the tertiary butanol finally enters the mixed ester of the materials at the top of the refining tower. The tertiary butanol is used as a polymerization inhibitor and can be recycled in the reactor for reuse in the system.

The mixed ester contains water, C8, tert-butyl alcohol and tert-butyl acetate, the tert-butyl alcohol in the mixed ester is required to be recycled, a rectification separation method is usually adopted, tower top materials contain water, C8, tert-butyl alcohol and tert-butyl acetate, tower bottom materials are the tert-butyl alcohol and the tert-butyl acetate, tower bottom materials can return to a reactor, the tert-butyl alcohol is recycled, but the tert-butyl alcohol in the tower top materials cannot be recycled and is directly discharged to a mixed ester tank as the mixed ester, and the recovery rate of the tert-butyl alcohol in the whole system is low.

Meanwhile, in the existing technology for preparing tert-butyl acetate, side reactions are more, so that the content of impurities in a reaction product is higher, and tert-butyl acetate is decomposed at high temperature in the separation process, so that the yield of tert-butyl acetate is lower.

In order to solve the problems of low recovery rate of tert-butyl acetate, more reaction byproducts and low recovery rate of tert-butyl alcohol in the prior art, the technical scheme of controlling the reaction temperature of the reactor in sections is provided, and by controlling the reaction temperature, particularly the reaction temperature of the second section, the side reaction is reduced, and the byproducts after the reaction are reduced. The technical scheme of removing light components at low temperature is adopted, so that the decomposition of the tert-butyl acetate is inhibited, and the yield of the tert-butyl acetate is improved. The recovery rate of the tertiary butanol is improved by adopting a mode of re-separating after extracting the mixed ester with water.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a preparation method of tert-butyl acetate, which can effectively inhibit the occurrence of side reactions, reduce byproducts after the reaction, inhibit the pyrolysis of the tert-butyl acetate, improve the selectivity and yield of the tert-butyl acetate, and ensure that the selectivity of the tert-butyl acetate reaches more than 99.5 percent and the yield reaches more than 90 percent. The method can also effectively separate the mixture containing C8, tert-butyl acetate and tert-butyl alcohol obtained from the top of the refining tower, and recover tert-butyl alcohol, thereby greatly improving the recovery rate of tert-butyl alcohol, and the recovery rate of tert-butyl alcohol can reach more than 99.95%. The method has the advantages of simple process, easy operation and low energy consumption.

In order to achieve the above object, according to a first aspect of the present invention, there is provided a process for producing tert-butyl acetate, which comprises: (1) sending acetic acid and isobutene or a mixture C4 containing isobutene into an esterification reactor, adding a polymerization inhibitor tert-butyl alcohol, and reacting under esterification reaction conditions; (2) sending the mixture obtained after the reaction into a light component removal tower for separation, obtaining an unreacted C4 component at the tower top, and obtaining a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol at the tower bottom; (3) sending a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol obtained at the bottom of the light component removal tower into a de-acetic acid tower for separation, obtaining a mixture of tert-butyl acetate, C8 and tert-butyl alcohol at the top of the tower, and obtaining acetic acid at the bottom of the tower; (4) feeding the mixture of tert-butyl acetate, C8 and tert-butyl alcohol obtained from the tower top of the de-acetic acid tower into a product refining tower for refining, obtaining a mixture of tert-butyl acetate, C8 and tert-butyl alcohol from the tower top, and obtaining a product of tert-butyl acetate from the tower bottom; (5) sending a mixture of tert-butyl acetate, C8 and tert-butyl alcohol obtained from the top of the product refining tower into an extraction tower for extraction, extracting C8 and tert-butyl acetate from the top of the extraction tower, and extracting a mixture of tert-butyl alcohol and water from the bottom of the extraction tower; (6) and (3) feeding a mixture of the tertiary butanol extracted from the bottom of the extraction tower and water into a rectifying tower for separation, extracting the tertiary butanol containing water from the top of the tower, and extracting the water from the bottom of the tower.

In the present invention, the reaction may be carried out using acetic acid and isobutylene as raw materials, or using acetic acid and a mixed C4 containing isobutylene as raw materials. According to the invention, acetic acid reacts with isobutene to prepare tert-butyl acetate, and the reacted mixture mainly comprises 20% -30% of tert-butyl acetate, 1% -10% of tert-butyl alcohol, 60% -70% of acetic acid, 1% -5% of C8, 1% -10% of isobutene and 1% -3% of water, based on the total mass of the reacted mixture. When acetic acid and mixed C4 containing isobutene are used for preparing tert-butyl acetate, the content of each component in the mixed C4 raw material containing isobutene is as follows: 30-40 wt% of isobutane, 10-20 wt% of n-butene, 10-20 wt% of n-butane, 10-20 wt% of isobutene, 10-20 wt% of butylene, 5-15 wt% of n-butene, 0.01-0.1 wt% of carbon trioxide and 0.1-0.5 wt% of butadiene, wherein the total mass of the raw material of the mixed C4 containing isobutene is taken as a reference. In the mixture after reaction, the contents of the components are as follows: 30-60% of acetic acid, 30-60% of mixed C4, 10-20% of tert-butyl acetate, 0.5-3% of tert-butyl alcohol, 0.01-1% of C8 and 0.01-1% of water, based on the total mass of the mixture after reaction.

In the invention, the esterification reactor is divided into 2 sections to respectively control the reaction temperature, and in the invention, if the reaction temperature is too low, the conversion rate of isobutene is not high enough, and if the reaction temperature is too high, the polymerization is serious. Therefore, in the invention, the reaction temperature is controlled in stages, and the temperature of the first stage reaction is controlled to be 18-25 ℃, preferably 19-25 ℃, more preferably 20-25 ℃, more preferably 21-25 ℃, more preferably 22-25 ℃, and further preferably 23-25 ℃; the temperature of the second stage reactor is controlled to be 18 to 30 ℃, preferably 20 to 30 ℃, more preferably 20 to 28 ℃, more preferably 20 to 26 ℃, more preferably 21 to 26 ℃, and further preferably 22 to 25 ℃, and the temperature difference between the first stage (usually the lower half) and the second stage (usually the upper half) is 5 ℃ or less, preferably 4 ℃ or less, more preferably 3 ℃ or less, and further preferably 0 ℃ or less. The sectional control of the reaction temperature can be realized by respectively arranging heat exchange jackets at the lower half section and the upper half section of the esterification reactor and controlling the water temperature in the heat exchange jackets. In the invention, experiments show that the occurrence of reaction side reactions can be reduced by controlling the temperature of the reactor, particularly the temperature of the latter half of the reaction is particularly important, in the prior art, the whole reaction system is exothermic, the reaction temperature gradually increases from the inlet of the reactor to the outlet of the reactor, the reaction temperature of the latter half is not easy to control, and the outlet temperature of the reactor is about 6-10 ℃ higher than the inlet temperature of the reactor. In the invention, the reactor is divided into 2 sections, and the temperature of the reactor is controlled in sections to reduce the occurrence of side reactions, thereby improving the selectivity of the tert-butyl acetate.

In the present invention, in order to ensure that the raw material isobutylene or the mixed C4 feed is in a liquid state, the reaction needs to ensure a certain pressure, and the reaction pressure is 0.6 to 1.2MPa, preferably 0.7 to 1.2MPa, more preferably 0.8 to 1.1MPa, and further preferably 0.8 to 1.0 MPa. In the present invention, the acid-olefin ratio is 3 to 10:1, preferably 3 to 9:1, more preferably 3 to 8:1, more preferably 3 to 7:1, more preferably 3 to 6:1, more preferably 4 to 6:1, and further preferably 5 to 6:1, and too low an acid-olefin ratio results in low conversion of isobutylene and more formation of polymer, and too high an acid-olefin ratio results in too low a conversion of acetic acid and further increases energy consumption for separation. In the invention, the experiment of reacting acetic acid and isobutene to generate tert-butyl acetate is a reversible reaction, the tert-butyl acetate can be decomposed to generate acetic acid and isobutene, and the retention time of materials in the reactor is not suitable to be too long. The higher the temperature, the shorter the residence time should be. In the present invention, the reaction residence time is 15 to 80min, preferably 15 to 75min, more preferably 15 to 70min, more preferably 15 to 65min, more preferably 15 to 60min, more preferably 18 to 60min, and further preferably 20 to 60 min. In the present invention, it is necessary to add a proper amount of t-butyl alcohol to acetic acid to suppress the formation of polymer C8, and the amount of t-butyl alcohol added as a polymerization inhibitor is 1 wt% to 10 wt%, preferably 2 wt% to 10 wt%, more preferably 3 wt% to 10 wt%, more preferably 4 wt% to 10 wt%, more preferably 5 wt% to 9 wt%, more preferably 5 wt% to 8.5 wt%, and still more preferably 5 wt% to 8 wt% of the amount of acetic acid added.

In the present invention, it has been found through studies that t-butyl acetate containing no acid and having a purity of 99% or more is stable and does not decompose at a temperature of 125 ℃ and that t-butyl acetate containing acetic acid decomposes in a minute amount after one hour, and therefore, the column bottom temperature of each separation column should be controlled to 125 ℃ or less in order to prevent the decomposition of t-butyl acetate during the separation.

In the invention, the tower top pressure of the light component removing tower is normal pressure, and the refrigerating fluid required by the tower top is provided by a refrigerating unit at the temperature of-20 to-5 ℃. The tower top temperature of the light component removal tower is-10 ℃, preferably-10-8 ℃, more preferably-10-6 ℃, more preferably-10-5 ℃, more preferably-10-4 ℃, more preferably-10-2 ℃, more preferably-10-0 ℃, more preferably-8-0 ℃, and more preferably-8-2 ℃; the bottom temperature is 105-125 ℃, preferably 105-122 ℃, more preferably 105-120 ℃, more preferably 105-118 ℃, more preferably 105-116 ℃, more preferably 105-115 ℃, more preferably 108-115 ℃, and more preferably 110-115 ℃; the reflux ratio is 1-10:1, preferably 2 to 10:1, more preferably 2 to 9:1, more preferably 2 to 8:1, more preferably 2 to 7:1, more preferably 2 to 6:1, more preferably 2 to 5:1, and further preferably 3 to 5: 1.

In the invention, the tower top pressure of the acetic acid removing tower is normal pressure, the tower top temperature is 80-100 ℃, preferably 80-98 ℃, more preferably 80-96 ℃, more preferably 80-95 ℃, more preferably 82-95 ℃, more preferably 84-95 ℃, more preferably 85-95 ℃, and more preferably 86-92 ℃; the bottom temperature is 115-125 ℃, preferably 115-124 ℃, more preferably 115-123 ℃, more preferably 115-122 ℃, more preferably 116-122 ℃, more preferably 118-122 ℃, more preferably 119-122 ℃, and more preferably 120-122 ℃; the reflux ratio is 1 to 10:1, preferably 2 to 10:1, more preferably 2 to 9:1, more preferably 2 to 8:1, more preferably 2 to 7:1, more preferably 2 to 6:1, more preferably 2 to 5:1, and further preferably 3 to 5: 1.

In the invention, the top pressure of the product refining tower is normal pressure, and the top temperature of the product refining tower is 80-90 ℃, preferably 80-89 ℃, more preferably 80-88 ℃, more preferably 80-87 ℃, more preferably 80-86 ℃, more preferably 80-85 ℃, and more preferably 80-84 ℃; the bottom temperature is 95-105 ℃, preferably 96-105 ℃, more preferably 97-105 ℃, more preferably 98-105 ℃, more preferably 99-105 ℃, more preferably 100-105 ℃, and further preferably 100-104 ℃; the reflux ratio is 1 to 10:1, preferably 2 to 10:1, more preferably 2 to 9:1, more preferably 2 to 8:1, more preferably 2 to 7:1, more preferably 2 to 6:1, more preferably 2 to 5:1, and further preferably 3 to 5: 1.

In the prior art, a common rectification separation method is adopted to separate a mixture of tert-butyl acetate, C8, water and tert-butyl alcohol obtained from the top of a refining tower, wherein the mixture of tert-butyl acetate, C8, water and tert-butyl alcohol is obtained from the top of the refining tower, tower top materials comprise water, C8, tert-butyl alcohol and tert-butyl acetate, tower bottom materials comprise tert-butyl alcohol and tert-butyl acetate, and tower bottom materials can be returned to a reactor for recycling, but the tert-butyl alcohol in the tower top materials cannot be recycled. Because the composition of the azeotrope is complex, the tertiary butanol (boiling point 82.5 ℃) can form various binary and ternary azeotropes with water (boiling point 100 ℃), tertiary butyl acetate (boiling point 96.0 ℃) and C8(2,4, 4-trimethyl-1-pentene (boiling point 101.4 ℃), 2,4, 4-trimethyl-2-pentene (boiling point 104.0 ℃)), and the compositions of the azeotropes are as follows:

therefore, the mixture of water, C8, tert-butyl alcohol and tert-butyl acetate obtained at the top of the tower contains a large amount of tert-butyl alcohol, and only the tert-butyl alcohol in the tower bottom material is recovered, so that the recovery rate of the tert-butyl alcohol in the whole system is low and is below 70%.

In the present invention, a mixture of tert-butyl acetate, C8, water and tert-butanol obtained at the top of the purification column is taken as a raw material for further separation and purification. In the invention, the content of C8 in a mixture containing C8, tert-butyl acetate, water and tert-butyl alcohol obtained from the top of the refining tower is 10-30%, the content of tert-butyl acetate is 20-40%, the content of tert-butyl alcohol is 40-60%, and the content of water is 1-3%, based on the total mass of the mixture containing C8, tert-butyl acetate, tert-butyl alcohol and water.

In the present invention, the extraction column is a packed column, and the number of theoretical plates of the extraction column is 5 to 30, preferably 5 to 25, more preferably 5 to 20, more preferably 5 to 15, more preferably 5 to 12, more preferably 5 to 10, and further preferably 5 to 8.

In the present invention, the operation conditions of the extraction column are normal temperature and normal pressure, and the volume ratio of the extractant water to the mixture containing C8, t-butyl acetate, t-butanol, and water obtained at the top of the refining column fed to the extraction column is 2 to 5:1, preferably 2.2 to 4.8:1, more preferably 2.5 to 4.5:1, more preferably 2.8 to 4.2:1, and still more preferably 3 to 4: 1.

In the invention, the oil phase obtained from the top of the extraction tower is mainly C8 hydrocarbon, which contains no water basically and can be directly fed into a C8 hydrocarbon intermediate tank to be sold as a product. In the prior art, the mixture of tert-butyl acetate, C8, water and tert-butyl alcohol obtained from the top of a refining tower is further separated by adopting common rectification, the mixture of water, C8, tert-butyl alcohol and tert-butyl acetate obtained from the top of the refining tower contains a large amount of tert-butyl alcohol, and the mixture of water, C8, tert-butyl alcohol and tert-butyl acetate obtained from the top of the refining tower cannot be layered due to mutual solubility of water and tert-butyl alcohol and partial mutual solubility of C8 and tert-butyl acetate, and other separation methods are also needed to further separate the materials if the materials are used, so that equipment investment and energy consumption are increased.

In the invention, the operation condition of the rectifying tower is normal pressure, the tower top temperature is 70-82 ℃, preferably 72-82 ℃, more preferably 75-82 ℃, more preferably 78-82 ℃, and further preferably 80-82 ℃; the bottom temperature is in the range of 90 to 110 ℃, preferably 92 to 108 ℃, more preferably 94 to 106 ℃, more preferably 96 to 104 ℃, still more preferably 98 to 102 ℃, and the reflux ratio is 1 to 10:1, preferably 1 to 10:1, more preferably 1 to 8:1, more preferably 1 to 7:1, more preferably 1 to 6:1, more preferably 1 to 5:1, more preferably 1 to 4:1, more preferably 2 to 3: 1.

in the invention, in order to recycle the aqueous solution of the polymerization inhibitor tert-butyl alcohol at the top of the rectifying tower, the water at the bottom of the rectifying tower and the acetic acid at the bottom of the acetic acid removing tower, the water-containing tert-butyl alcohol extracted from the top of the rectifying tower is directly sent to an esterification reactor for recycling, the water extracted from the bottom of the rectifying tower is sent to an extraction tower for recycling, and the acetic acid extracted from the bottom of the acetic acid removing tower is sent to the esterification reactor for recycling.

In the present invention, when the mixed C4 containing isobutylene is selected as the reaction raw material, it is preferable that unreacted isobutylene obtained from the top of the light ends removal column is recovered by absorption or by a compressor and recycled to the reactor for reaction.

In order to achieve the above object, according to a first aspect of the present invention, there is provided an apparatus for producing tert-butyl acetate, which comprises a reactor, a light component removal column, an acetic acid removal column, a product refining column, an extraction column and a rectification column connected in sequence, wherein the light component removal column, the acetic acid removal column, the product refining column and the rectification column each comprise a column top condenser, a reflux tank, a column bottom reboiler, a feed inlet, a column top discharge outlet and a column bottom discharge outlet, the esterification reactor is provided with a feed inlet and a discharge outlet, the extraction column has a water inlet, a feed inlet and a discharge outlet, the discharge outlet of the esterification reactor is connected with the feed inlet of the light component removal column through a pipeline, the column bottom discharge outlet of the light component removal column is connected with the feed inlet of the acetic acid removal column through a pipeline, the column top discharge outlet of the acetic acid removal column is connected with the column top reflux tank through a pipeline, the discharge outlet of the, the material outlet of the tower top of the product refining tower is connected with the tower top reflux tank through a pipeline, the material outlet of the tower top reflux tank is connected with the material inlet of the extraction tower through a pipeline, and the material outlet of the tower bottom of the extraction tower is connected with the material inlet of the rectification tower through a pipeline.

Preferably, in order to recycle the unreacted acetic acid, the bottom discharge port of the acetic acid removal tower is connected with the feed port of the esterification reactor through a pipeline.

More optionally, in order to recover the aqueous solution of the polymerization inhibitor tert-butyl alcohol, the discharge hole at the top of the rectifying tower is connected with the feed hole of the esterification reactor through a pipeline. Alternatively, the outlet of the aqueous tertiary butanol solution at the top of the rectifying tower is connected with a tertiary butanol intermediate tank.

Further preferably, in order to recover water at the bottom of the rectifying tower, the water outlet at the bottom of the rectifying tower is connected with the water inlet of the extracting tower through a pipeline.

The method provided by the invention successfully solves the problems of low recovery rate of tert-butyl acetate, more reaction byproducts and low recovery rate of tert-butyl alcohol in the prior art, can effectively inhibit side reactions, reduces byproducts after the reaction, simultaneously inhibits the pyrolysis of tert-butyl acetate, improves the selectivity and yield of tert-butyl acetate, and ensures that the selectivity of tert-butyl acetate is over 99.5 percent and the yield is over 90 percent. The method can also effectively separate the mixture containing C8, tert-butyl acetate and tert-butyl alcohol obtained from the top of the refining tower and recover the tert-butyl alcohol, the purity of the tert-butyl alcohol separated by the technology of the invention is more than 85%, the tert-butyl alcohol can be directly recycled to a reactor for reacting isobutene with acetic acid for recycling, the recovery rate of the tert-butyl alcohol is greatly improved, and the recovery rate of the tert-butyl alcohol can reach more than 99.5%. The method has the advantages of simple process, easy operation and low energy consumption.

Drawings

FIG. 1 is a schematic diagram of an apparatus for preparing tert-butyl acetate according to the present invention.

Wherein 1 is raw material isobutene or mixed C4 containing isobutene, 2 is raw material acetic acid, 3 is an esterification reactor, 4 is a mixture after esterification reaction, 5 is a light component removing tower, 6 is a light component removing tower top extraction, 7 is a light component removing tower top condenser, 8 is a light component removing tower top reflux tank, 9 is a light component removing tower top reflux tank, 10 is a light component removing tower top reflux tank extraction, 11 is a light component removing tower bottom reboiler, 12 is a light component removing tower bottom extraction, 13 is a deacetic acid removing tower, 14 is a deacetic acid removing tower top extraction, 15 is an deacetic acid removing tower top condenser, 16 is an deacetic acid removing tower top reflux tank, 17 is an deacetic acid removing tower top reflux, 18 is an deacetic acid removing tower top reflux tank extraction, 19 is an deacetic acid removing tower bottom reboiler, 20 is an deacetic acid removing tower extraction, 21 is a product refining tower bottom, 22 is a product top extraction, 23 is a refining tower top condenser, 24 is a product refining tower top reflux drum, 25 is a product refining tower top reflux, 26 is a product refining tower top reflux drum extraction, 27 is a product refining tower bottom reboiler, 28 is a product refining tower bottom extraction, 29 is an extractant water, 30 is an extraction tower, 31 is an extraction tower top extraction, 32 is an extraction tower bottom extraction, 33 is a rectification tower, 34 is a rectification tower top extraction, 35 is a rectification tower top condenser, 36 is a rectification tower top reflux drum, 37 is a rectification tower top reflux, 38 is a rectification tower top reflux drum extraction, 39 is a rectification tower bottom reboiler, and 40 is a rectification tower bottom extraction.

Detailed Description

The invention is further illustrated by the following examples. However, the present invention is not limited to the following examples, and various changes may be made to the present invention within a range not departing from the gist of the present invention, and these changes are still included in the scope of the present invention.

As shown in figure 1, the device for preparing the tert-butyl acetate comprises an esterification reactor 3, a light component removal tower 5, an acetic acid removal tower 13, a product refining tower 21, an extraction tower 30 and a rectification tower 33 which are connected in sequence, wherein the light component removal tower 5, the acetic acid removal tower 13, the product refining tower 21 and the rectification tower 33 respectively comprise a tower top condenser (7, 15, 23, 35), a reflux tank (8,16,24,36), a tower bottom reboiler (11,19,27,39), a feeding port, a tower top discharging port and a tower bottom discharging port, the esterification reactor 3 is provided with a feeding port and a discharging port, the extraction tower 30 is provided with a water inlet, a feeding port and a discharging port, the discharging port of the esterification reactor 3 is connected with the feeding port of the light component removal tower 5 through a pipeline, the tower bottom discharging port of the light component removal tower 5 is connected with the feeding port of the acetic acid removal tower 13 through a pipeline, the tower top discharging port of the acetic acid removal tower, the discharge hole of the tower top reflux tank 16 is connected with the feed hole of the product refining tower 21 through a pipeline, the discharge hole of the tower top of the product refining tower 21 is connected with the tower top reflux tank 24 through a pipeline, the discharge hole of the tower top reflux tank 24 is connected with the feed hole of the extraction tower 30 through a pipeline, and the discharge hole of the tower bottom of the extraction tower 30 is connected with the feed hole of the rectification tower 33 through a pipeline.

Preferably, the bottom outlet of the acetic acid removing column 13 is connected to the inlet of the esterification reactor 3 through a line in order to recycle the unreacted acetic acid.

More optionally, in order to recover the aqueous solution of the inhibitor tert-butanol, the top outlet of the rectification column 33 is connected to the inlet of the esterification reactor 3 via a line. Alternatively, the outlet of the aqueous tertiary butyl alcohol solution at the top of the rectifying tower 33 is connected with a tertiary butyl alcohol intermediate tank.

Further preferably, in order to recover the water at the bottom of the rectifying tower, the water outlet at the bottom of the rectifying tower 33 is connected with the water inlet of the extracting tower 30 through a pipeline.

The preparation method of the tert-butyl acetate comprises the following steps: (1) sending acetic acid 2 and isobutene or a mixture C41 containing isobutene into an esterification reactor 3, adding a polymerization inhibitor tert-butyl alcohol, and reacting under esterification reaction conditions; (2) the mixture 4 after the esterification reaction is sent into a light component removal tower 5 for separation, unreacted C4 components (extracted from the top of the light component removal tower 6) are obtained at the tower top, part of the unreacted C4 components are taken as tower top reflux 9 of the light component removal tower after passing through a tower top reflux tank 8, part of the unreacted C4 components are taken as tower top reflux 10 of the light component removal tower, and a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol (extracted from the bottom of the light component removal tower 12) is obtained at the tower bottom; (3) sending a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol obtained at the bottom of the light component removal tower into a de-acetic acid tower 13 for separation, obtaining a mixture of tert-butyl acetate, C8 and tert-butyl alcohol at the top of the tower (a tower top recovery 14 of the de-acetic acid tower), taking part of the mixture as a tower top reflux 17 of the de-acetic acid tower after passing through a tower top reflux tank, taking part of the mixture as a tower top reflux tank of the de-acetic acid tower to recover 18, and obtaining acetic acid at the bottom of the tower; (4) sending the recovery 18 of the tower top reflux tank of the de-acetic acid tower into a product refining tower 21, obtaining a mixture of tert-butyl acetate, C8 and tert-butyl alcohol at the tower top (the recovery 22 at the tower top of the product refining tower), passing through a tower top reflux tank 24, taking part of the mixture as the tower top reflux 25 of the product refining tower, taking part of the mixture as the recovery 26 of the tower top reflux tank of the product refining tower, and obtaining the product of tert-butyl acetate at the tower bottom (the recovery 28 at the tower bottom of the product refining tower); (5) sending a product refining tower top reflux tank extraction 26 into an extraction tower 30, extracting C8 and tert-butyl acetate (extraction tower top extraction 31) from the extraction tower top, and extracting a mixture of tert-butyl alcohol and water from the tower bottom (extraction tower bottom extraction 32); (6) the mixture of the tertiary butanol extracted from the bottom of the extraction tower and water is sent into a rectifying tower 33 for separation, the tertiary butanol containing water (extracted from the top of the rectifying tower 34) is extracted from the top of the tower, and is partially used as rectifying tower top reflux 37 after passing through a tower top reflux tank 36, and is partially used as rectifying tower top reflux tank extracted 38 and returned to the esterification reactor 3, and the water is extracted from the bottom of the tower (extracted from the bottom of the rectifying tower 40).

Example 1

Sending acetic acid and isobutene into an esterification reactor, adding a polymerization inhibitor tert-butyl alcohol, reacting under the esterification reaction condition, dividing the esterification reactor into 2 sections, respectively controlling the reaction temperature, controlling the temperature of the first section of reaction to be 18 ℃, controlling the temperature of the second section of reactor to be 18 ℃, controlling the reaction pressure to be 0.6MPa, controlling the acid-olefin ratio to be 3:1, and controlling the reaction residence time to be 80min, wherein the addition amount of the polymerization inhibitor tert-butyl alcohol is 10 wt% of the addition amount of the acetic acid. The content of the mixture obtained after the reaction was: 20.45 wt% of tertiary butyl acetate, 5.12 wt% of tertiary butyl alcohol, 68.54 wt% of acetic acid, C82.12wt%, 2.55 wt% of isobutene and 1.22 wt% of water, feeding the reacted mixture into a light component removal tower for separation, wherein the tower top pressure of the light component removal tower is normal pressure, the tower top temperature is-10 ℃, the tower bottom temperature is 105 ℃, and the reflux ratio is 1: 1. unreacted C4 component is obtained at the top of the tower, and a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the bottom of the tower. Sending a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol obtained at the bottom of the light component removal tower into a de-acetic acid tower for separation, wherein the pressure of the de-acetic acid tower is normal pressure, the temperature of the top of the tower is 80 ℃, the temperature of the bottom of the tower is 115 ℃, and the reflux ratio is 1: 1. A mixture of tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and acetic acid obtained at the tower bottom returns to the esterification reactor for recycling; the mixture of the tertiary butyl acetate, C8 and tertiary butanol obtained from the tower top of the deacidification tower is sent into a product refining tower, the tower top pressure of the product refining tower is normal pressure, the tower top temperature is 80 ℃, the tower bottom temperature is 95 ℃, and the reflux ratio is 1: 1. The mixture of the tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and the product tert-butyl acetate is obtained at the tower bottom; the mixture of the tertiary butyl acetate, the C8 and the tertiary butanol obtained from the top of the product refining tower is sent into an extraction tower, the extraction tower is a packed tower, the number of theoretical plates of the extraction tower is 5, the operation conditions of the extraction tower are normal temperature and normal pressure, and the volume ratio of the extractant water to the mixture containing the C8, the tertiary butyl acetate, the tertiary butanol and the water obtained from the top of the refining tower sent into the extraction tower is 2: 1. C8, extracting tert-butyl acetate from the top of the extraction tower, and extracting a mixture of tert-butyl alcohol and water from the bottom of the extraction tower; and (2) feeding a mixture of tert-butyl alcohol and water extracted from the bottom of the extraction tower into a rectifying tower for separation, wherein the operating conditions of the rectifying tower are normal pressure, the temperature of the top of the tower is 70 ℃, the temperature of the bottom of the tower is 90 ℃, and the reflux ratio is 1: 1. the tertiary butanol containing water is extracted from the top of the tower and then directly sent into the esterification reactor for recycling, and the water is extracted from the bottom of the tower and then sent into the extraction tower for recycling.

Through chromatographic analysis, the purity of the tert-butyl acetate product at the bottom of the product refining tower reaches 99.92%, the content of tert-butyl alcohol in the aqueous solution of tert-butyl alcohol obtained at the top of the rectifying tower is 86.88%, the selectivity of tert-butyl acetate reaches 99.62%, the yield reaches 90.54%, and the recovery rate of tert-butyl alcohol can reach 99.75%.

Example 2

Sending acetic acid and isobutene into an esterification reactor, adding a polymerization inhibitor tert-butyl alcohol, reacting under the esterification reaction condition, dividing the esterification reactor into 2 sections, respectively controlling the reaction temperature, controlling the reaction temperature of the first section to be 19 ℃, controlling the reaction temperature of the second section to be 20 ℃, controlling the reaction pressure to be 0.7MPa, controlling the acid-olefin ratio to be 4:1, controlling the reaction residence time to be 70min, and adding the polymerization inhibitor tert-butyl alcohol in an amount which is 8 wt% of the addition amount of the acetic acid. The content of the mixture obtained after the reaction was: 22.12 wt% of tertiary butyl acetate, 3.56 wt% of tertiary butanol, 64.77 wt% of acetic acid, 82.89wt% of C, 5.45 wt% of isobutene and 1.21 wt% of water, feeding the reacted mixture into a light component removal tower for separation, wherein the tower top pressure of the light component removal tower is normal pressure, the tower top temperature is-8 ℃, the tower bottom temperature is 108 ℃, and the reflux ratio is 2: 1. unreacted C4 component is obtained at the top of the tower, and a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the bottom of the tower. Sending a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol obtained at the bottom of the light component removal tower into a de-acetic acid tower for separation, wherein the pressure of the de-acetic acid tower is normal pressure, the temperature of the tower top is 82 ℃, the temperature of the tower bottom is 116 ℃, and the reflux ratio is 2: 1. A mixture of tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and acetic acid obtained at the tower bottom returns to the esterification reactor for recycling; and (3) feeding the mixture of the tert-butyl acetate, C8 and tert-butyl alcohol obtained at the top of the deacidification tower into a product refining tower, wherein the tower top pressure of the product refining tower is normal pressure, the tower top temperature is 82 ℃, the tower bottom temperature is 96 ℃, and the reflux ratio is 2: 1. The mixture of the tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and the product tert-butyl acetate is obtained at the tower bottom; the mixture of the tertiary butyl acetate, the C8 and the tertiary butanol obtained from the top of the product refining tower is sent into an extraction tower, the extraction tower is a packed tower, the number of theoretical plates of the extraction tower is 8, the operation conditions of the extraction tower are normal temperature and normal pressure, and the volume ratio of the extractant water to the mixture containing the C8, the tertiary butyl acetate, the tertiary butanol and the water obtained from the top of the refining tower sent into the extraction tower is 2.5: 1. C8, extracting tert-butyl acetate from the top of the extraction tower, and extracting a mixture of tert-butyl alcohol and water from the bottom of the extraction tower; and (2) feeding a mixture of tert-butyl alcohol and water extracted from the bottom of the extraction tower into a rectifying tower for separation, wherein the operating conditions of the rectifying tower are normal pressure, the temperature of the top of the tower is 72 ℃, the temperature of the bottom of the tower is 92 ℃, and the reflux ratio is 2: 1. the tertiary butanol containing water is extracted from the top of the tower and then directly sent into the esterification reactor for recycling, and the water is extracted from the bottom of the tower and then sent into the extraction tower for recycling.

Through chromatographic analysis, the purity of the tert-butyl acetate product at the bottom of the product refining tower reaches 99.94%, the content of tert-butyl alcohol in the aqueous solution of tert-butyl alcohol obtained at the top of the rectifying tower is 87.54%, the selectivity of tert-butyl acetate reaches 99.75%, the yield reaches 91.21%, and the recovery rate of tert-butyl alcohol reaches 99.81%.

Example 3

Sending acetic acid and isobutene into an esterification reactor, adding a polymerization inhibitor tert-butyl alcohol, reacting under the esterification reaction condition, dividing the esterification reactor into 2 sections, respectively controlling the reaction temperature, controlling the temperature of the first section of reaction to be 20 ℃, controlling the temperature of the second section of reactor to be 22 ℃, controlling the reaction pressure to be 0.8MPa, controlling the acid-olefin ratio to be 5:1, and controlling the reaction residence time to be 60min, wherein the addition amount of the polymerization inhibitor tert-butyl alcohol is 6 wt% of the addition amount of the acetic acid. The content of the mixture obtained after the reaction was: 24.14 wt% of tertiary butyl acetate, 6.45 wt% of tertiary butyl alcohol, 65.21 wt% of acetic acid, 81.81wt% of C, 1.22 wt% of isobutene and 1.17 wt% of water, feeding the reacted mixture into a light component removal tower for separation, wherein the tower top pressure of the light component removal tower is normal pressure, the tower top temperature is-5 ℃, the tower bottom temperature is 110 ℃, and the reflux ratio is 3: 1. unreacted C4 component is obtained at the top of the tower, and a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the bottom of the tower. Sending a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol obtained at the bottom of the light component removal tower into a de-acetic acid tower for separation, wherein the pressure of the de-acetic acid tower is normal pressure, the temperature of the top of the tower is 85 ℃, the temperature of the bottom of the tower is 118 ℃, and the reflux ratio is 4: 1. A mixture of tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and acetic acid obtained at the tower bottom returns to the esterification reactor for recycling; and (3) feeding the mixture of the tert-butyl acetate, C8 and tert-butyl alcohol obtained at the top of the deacidification tower into a product refining tower, wherein the top pressure of the product refining tower is normal pressure, the temperature at the top of the product refining tower is 84 ℃, the temperature at the bottom of the product refining tower is 98 ℃, and the reflux ratio is 4: 1. The mixture of the tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and the product tert-butyl acetate is obtained at the tower bottom; the mixture of the tertiary butyl acetate, the C8 and the tertiary butanol obtained from the top of the product refining tower is sent into an extraction tower, the extraction tower is a packed tower, the number of theoretical plates of the extraction tower is 10, the operation conditions of the extraction tower are normal temperature and normal pressure, and the volume ratio of the extractant water to the mixture containing the C8, the tertiary butyl acetate, the tertiary butanol and the water obtained from the top of the refining tower sent into the extraction tower is 2.8: 1. C8, extracting tert-butyl acetate from the top of the extraction tower, and extracting a mixture of tert-butyl alcohol and water from the bottom of the extraction tower; and (2) feeding a mixture of tert-butyl alcohol and water extracted from the bottom of the extraction tower into a rectifying tower for separation, wherein the operating conditions of the rectifying tower are normal pressure, the temperature of the top of the tower is 75 ℃, the temperature of the bottom of the tower is 95 ℃, and the reflux ratio is 3: 1. the tertiary butanol containing water is extracted from the top of the tower and then directly sent into the esterification reactor for recycling, and the water is extracted from the bottom of the tower and then sent into the extraction tower for recycling.

Through chromatographic analysis, the purity of the tert-butyl acetate product at the bottom of the product refining tower reaches 99.95%, the content of tert-butyl alcohol in the aqueous solution of tert-butyl alcohol obtained at the top of the rectifying tower is 86.23%, the selectivity of tert-butyl acetate reaches 99.58%, the yield reaches 90.98%, and the recovery rate of tert-butyl alcohol reaches 99.56%.

Example 4

Sending acetic acid and isobutene into an esterification reactor, adding a polymerization inhibitor tert-butyl alcohol, reacting under the esterification reaction condition, dividing the esterification reactor into 2 sections, respectively controlling the reaction temperature, controlling the temperature of the first section of reaction to be 21 ℃, controlling the temperature of the second section of reactor to be 24 ℃, controlling the reaction pressure to be 0.9MPa, controlling the acid-olefin ratio to be 6:1, and controlling the reaction residence time to be 50min, wherein the addition amount of the polymerization inhibitor tert-butyl alcohol is 5 wt% of the addition amount of the acetic acid. The content of the mixture obtained after the reaction was: 27.15 wt% of tertiary butyl acetate, 5.42 wt% of tertiary butanol, 60.31 wt% of acetic acid, 84.12wt% of C, 1.51 wt% of isobutene and 1.49 wt% of water, feeding the reacted mixture into a light component removal tower for separation, wherein the tower top pressure of the light component removal tower is normal pressure, the tower top temperature is-2 ℃, the tower bottom temperature is 112 ℃, and the reflux ratio is 5: 1. unreacted C4 component is obtained at the top of the tower, and a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the bottom of the tower. Sending a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol obtained at the bottom of the light component removal tower into a de-acetic acid tower for separation, wherein the pressure of the de-acetic acid tower is normal pressure, the temperature of the top of the tower is 88 ℃, the temperature of the bottom of the tower is 120 ℃, and the reflux ratio is 5: 1. A mixture of tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and acetic acid obtained at the tower bottom returns to the esterification reactor for recycling; and (3) feeding the mixture of the tert-butyl acetate, C8 and tert-butyl alcohol obtained at the top of the deacidification tower into a product refining tower, wherein the tower top pressure of the product refining tower is normal pressure, the tower top temperature is 85 ℃, the tower bottom temperature is 99 ℃, and the reflux ratio is 5: 1. The mixture of the tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and the product tert-butyl acetate is obtained at the tower bottom; the mixture of the tertiary butyl acetate, the C8 and the tertiary butanol obtained from the top of the product refining tower is sent into an extraction tower, the extraction tower is a packed tower, the number of theoretical plates of the extraction tower is 12, the operation conditions of the extraction tower are normal temperature and normal pressure, and the volume ratio of the extractant water to the mixture containing the C8, the tertiary butyl acetate, the tertiary butanol and the water obtained from the top of the refining tower sent into the extraction tower is 3: 1. C8, extracting tert-butyl acetate from the top of the extraction tower, and extracting a mixture of tert-butyl alcohol and water from the bottom of the extraction tower; and (2) feeding a mixture of tert-butyl alcohol and water extracted from the bottom of the extraction tower into a rectifying tower for separation, wherein the operating conditions of the rectifying tower are normal pressure, the temperature of the top of the tower is 76 ℃, the temperature of the bottom of the tower is 98 ℃, and the reflux ratio is 5: 1. the tertiary butanol containing water is extracted from the top of the tower and then directly sent into the esterification reactor for recycling, and the water is extracted from the bottom of the tower and then sent into the extraction tower for recycling.

Through chromatographic analysis, the purity of the tert-butyl acetate product at the bottom of the product refining tower reaches 99.96%, the content of tert-butyl alcohol in the aqueous solution of tert-butyl alcohol obtained at the top of the rectifying tower is 86.65%, the selectivity of tert-butyl acetate reaches 99.69%, the yield reaches 92.56%, and the recovery rate of tert-butyl alcohol can reach 99.65%.

Example 5

Sending acetic acid and isobutene-containing mixed C4 into an esterification reactor, adding a polymerization inhibitor tert-butyl alcohol, reacting under esterification reaction conditions, dividing the esterification reactor into 2 sections, respectively controlling the reaction temperature, controlling the first-stage reaction temperature to be 22 ℃, controlling the second-stage reactor temperature to be 25 ℃, controlling the reaction pressure to be 1.0MPa, controlling the acid-olefin ratio to be 7:1, and controlling the reaction residence time to be 40min, wherein the addition amount of the polymerization inhibitor tert-butyl alcohol is 4 wt% of the addition amount of the acetic acid. The content of the mixture obtained after the reaction was: 30.46 wt% of acetic acid, 16.12 wt% of mixed C451.42wt% of tert-butyl acetate, 1.45 wt% of tert-butyl alcohol, 80.35wt% of C and 0.20 wt% of water, feeding the reacted mixture into a light component removal tower for separation, wherein the tower top pressure of the light component removal tower is normal pressure, the tower top temperature is 0 ℃, the tower bottom temperature is 115 ℃, and the reflux ratio is 6: 1. unreacted C4 component is obtained at the top of the tower, and a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the bottom of the tower. Sending a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol obtained at the bottom of the light component removal tower into a de-acetic acid tower for separation, wherein the pressure of the de-acetic acid tower is normal pressure, the temperature of the top of the tower is 90 ℃, the temperature of the bottom of the tower is 121 ℃, and the reflux ratio is 6: 1. A mixture of tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and acetic acid obtained at the tower bottom returns to the esterification reactor for recycling; the mixture of the tertiary butyl acetate, C8 and tertiary butanol obtained from the tower top of the deacidification tower is sent into a product refining tower, the tower top pressure of the product refining tower is normal pressure, the tower top temperature is 86 ℃, the tower bottom temperature is 100 ℃, and the reflux ratio is 6: 1. The mixture of the tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and the product tert-butyl acetate is obtained at the tower bottom; the mixture of the tertiary butyl acetate, the C8 and the tertiary butanol obtained from the top of the product refining tower is sent into an extraction tower, the extraction tower is a packed tower, the number of theoretical plates of the extraction tower is 15, the operation conditions of the extraction tower are normal temperature and normal pressure, and the volume ratio of the extractant water to the mixture containing the C8, the tertiary butyl acetate, the tertiary butanol and the water obtained from the top of the refining tower sent into the extraction tower is 3.5: 1. C8, extracting tert-butyl acetate from the top of the extraction tower, and extracting a mixture of tert-butyl alcohol and water from the bottom of the extraction tower; and (2) feeding a mixture of tert-butyl alcohol and water extracted from the bottom of the extraction tower into a rectifying tower for separation, wherein the operating conditions of the rectifying tower are normal pressure, the temperature of the top of the tower is 78 ℃, the temperature of the bottom of the tower is 100 ℃, and the reflux ratio is 6: 1. the tertiary butanol containing water is extracted from the top of the tower and then directly sent into the esterification reactor for recycling, and the water is extracted from the bottom of the tower and then sent into the extraction tower for recycling.

Through chromatographic analysis, the purity of the tert-butyl acetate product at the bottom of the product refining tower reaches 99.97%, the content of tert-butyl alcohol in the aqueous solution of tert-butyl alcohol obtained at the top of the rectifying tower is 86.88%, the selectivity of tert-butyl acetate reaches 99.85%, the yield reaches 92.12%, and the recovery rate of tert-butyl alcohol can reach 99.78%.

Example 6

Sending acetic acid and isobutene-containing mixed C4 into an esterification reactor, adding a polymerization inhibitor tert-butyl alcohol, reacting under esterification reaction conditions, dividing the esterification reactor into 2 sections, respectively controlling the reaction temperature, controlling the first-stage reaction temperature to be 23 ℃, controlling the second-stage reactor temperature to be 26 ℃, controlling the reaction pressure to be 1.1MPa, controlling the acid-olefin ratio to be 8:1, and controlling the reaction residence time to be 30min, wherein the addition amount of the polymerization inhibitor tert-butyl alcohol is 3 wt% of the addition amount of the acetic acid. The content of the mixture obtained after the reaction was: 43.21 wt% of acetic acid, 440.45wt% of mixed C, 14.84 wt% of tert-butyl acetate, 1.21 wt% of tert-butyl alcohol, 80.17wt% of C and 0.12 wt% of water, feeding the reacted mixture into a light component removal tower for separation, wherein the tower top pressure of the light component removal tower is normal pressure, the tower top temperature is 2 ℃, the tower bottom temperature is 118 ℃, and the reflux ratio is 8: 1. unreacted C4 component is obtained at the top of the tower, and a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the bottom of the tower. Sending a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol obtained at the bottom of the light component removal tower into a de-acetic acid tower for separation, wherein the pressure of the de-acetic acid tower is normal pressure, the temperature of the tower top is 92 ℃, the temperature of the tower bottom is 122 ℃, and the reflux ratio is 7: 1. A mixture of tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and acetic acid obtained at the tower bottom returns to the esterification reactor for recycling; the mixture of the tertiary butyl acetate, C8 and tertiary butanol obtained from the tower top of the deacidification tower is sent into a product refining tower, the tower top pressure of the product refining tower is normal pressure, the tower top temperature is 87 ℃, the tower bottom temperature is 102 ℃, and the reflux ratio is 7: 1. The mixture of the tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and the product tert-butyl acetate is obtained at the tower bottom; and (2) feeding the mixture of the tertiary butyl acetate, the C8 and the tertiary butanol obtained from the top of the product refining tower into an extraction tower, wherein the extraction tower is a packed tower, the number of theoretical plates of the extraction tower is 20, the operation conditions of the extraction tower are normal temperature and normal pressure, and the volume ratio of the extractant water to the mixture containing the C8, the tertiary butyl acetate, the tertiary butanol and the water obtained from the top of the refining tower fed into the extraction tower is 4: 1. C8, extracting tert-butyl acetate from the top of the extraction tower, and extracting a mixture of tert-butyl alcohol and water from the bottom of the extraction tower; and (2) feeding a mixture of tert-butyl alcohol and water extracted from the bottom of the extraction tower into a rectifying tower for separation, wherein the operating conditions of the rectifying tower are normal pressure, the temperature of the top of the tower is 79 ℃, the temperature of the bottom of the tower is 105 ℃, and the reflux ratio is 8: 1. the tertiary butanol containing water is extracted from the top of the tower and then directly sent into the esterification reactor for recycling, and the water is extracted from the bottom of the tower and then sent into the extraction tower for recycling.

Through chromatographic analysis, the purity of the tert-butyl acetate product at the bottom of the product refining tower reaches 99.98%, the content of tert-butyl alcohol in the aqueous solution of tert-butyl alcohol obtained at the top of the rectifying tower is 85.88%, the selectivity of tert-butyl acetate reaches 99.76%, the yield reaches 93.34%, and the recovery rate of tert-butyl alcohol can reach 99.59%.

Example 7

Sending acetic acid and isobutene-containing mixed C4 into an esterification reactor, adding a polymerization inhibitor tert-butyl alcohol, reacting under esterification reaction conditions, dividing the esterification reactor into 2 sections, respectively controlling the reaction temperature, controlling the first-stage reaction temperature to be 24 ℃, controlling the second-stage reactor temperature to be 28 ℃, controlling the reaction pressure to be 1.2MPa, controlling the acid-olefin ratio to be 9:1, and controlling the reaction residence time to be 20min, wherein the addition amount of the polymerization inhibitor tert-butyl alcohol is 2 wt% of the addition amount of the acetic acid. The content of the mixture obtained after the reaction was: 50.12 wt% of acetic acid, 12.68 wt% of mixed C436.46wt% of tert-butyl acetate, 0.61 wt% of tert-butyl alcohol, 80.112wt% of C and 0.018 wt% of water, feeding the reacted mixture into a light component removal tower for separation, wherein the tower top pressure of the light component removal tower is normal pressure, the tower top temperature is 5 ℃, the tower bottom temperature is 120 ℃, and the reflux ratio is 9: 1. unreacted C4 component is obtained at the top of the tower, and a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the bottom of the tower. Sending a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol obtained at the bottom of the light component removal tower into a de-acetic acid tower for separation, wherein the pressure of the de-acetic acid tower is normal pressure, the temperature of the top of the tower is 95 ℃, the temperature of the bottom of the tower is 124 ℃, and the reflux ratio is 8: 1. A mixture of tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and acetic acid obtained at the tower bottom returns to the esterification reactor for recycling; and (3) feeding the mixture of the tert-butyl acetate, C8 and tert-butyl alcohol obtained at the top of the deacidification tower into a product refining tower, wherein the top pressure of the product refining tower is normal pressure, the temperature at the top of the product refining tower is 88 ℃, the temperature at the bottom of the product refining tower is 104 ℃, and the reflux ratio is 8: 1. The mixture of the tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and the product tert-butyl acetate is obtained at the tower bottom; the mixture of the tertiary butyl acetate, the C8 and the tertiary butanol obtained from the top of the product refining tower is sent into an extraction tower, the extraction tower is a packed tower, the theoretical plate number of the extraction tower is 25, the operation condition of the extraction tower is normal temperature and normal pressure, and the volume ratio of the extractant water to the mixture containing the C8, the tertiary butyl acetate, the tertiary butanol and the water obtained from the top of the refining tower sent into the extraction tower is 4.5: 1. C8, extracting tert-butyl acetate from the top of the extraction tower, and extracting a mixture of tert-butyl alcohol and water from the bottom of the extraction tower; and (2) feeding a mixture of tert-butyl alcohol and water extracted from the bottom of the extraction tower into a rectifying tower for separation, wherein the operating conditions of the rectifying tower are normal pressure, the temperature of the top of the tower is 80 ℃, the temperature of the bottom of the tower is 108 ℃, and the reflux ratio is 9: 1. the tertiary butanol containing water is extracted from the top of the tower and then directly sent into the esterification reactor for recycling, and the water is extracted from the bottom of the tower and then sent into the extraction tower for recycling.

Through chromatographic analysis, the purity of the tert-butyl acetate product at the bottom of the product refining tower reaches 99.95%, the content of tert-butyl alcohol in the aqueous solution of tert-butyl alcohol obtained at the top of the rectifying tower is 87.96%, the selectivity of tert-butyl acetate reaches 99.91%, the yield reaches 94.12%, and the recovery rate of tert-butyl alcohol reaches 99.75%.

Example 8

Sending acetic acid and isobutene-containing mixed C4 into an esterification reactor, adding a polymerization inhibitor tert-butyl alcohol, reacting under esterification reaction conditions, dividing the esterification reactor into 2 sections, respectively controlling the reaction temperature, controlling the first-stage reaction temperature to be 25 ℃, controlling the second-stage reactor temperature to be 30 ℃, controlling the reaction pressure to be 1.0MPa, controlling the acid-olefin ratio to be 10:1, and controlling the reaction residence time to be 15min, wherein the addition amount of the polymerization inhibitor tert-butyl alcohol is 1 wt% of the addition amount of the acetic acid. The content of the mixture obtained after the reaction was: 58.24 wt% of acetic acid, 430.45wt% of mixed C, 10.49 wt% of tert-butyl acetate, 0.71 wt% of tert-butyl alcohol, 80.085 wt% of C and 0.025 wt% of water, feeding the reacted mixture into a light component removal tower for separation, wherein the tower top pressure of the light component removal tower is normal pressure, the tower top temperature is 8 ℃, the tower bottom temperature is 122 ℃, and the reflux ratio is 10: 1. unreacted C4 component is obtained at the top of the tower, and a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the bottom of the tower. Sending a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol obtained at the bottom of the light component removal tower into a de-acetic acid tower for separation, wherein the pressure of the de-acetic acid tower is normal pressure, the temperature of the top of the tower is 100 ℃, the temperature of the bottom of the tower is 125 ℃, and the reflux ratio is 10: 1. A mixture of tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and acetic acid obtained at the tower bottom returns to the esterification reactor for recycling; and (3) feeding the mixture of the tert-butyl acetate, C8 and tert-butyl alcohol obtained at the top of the deacidification tower into a product refining tower, wherein the top pressure of the product refining tower is normal pressure, the temperature at the top of the product refining tower is 90 ℃, the temperature at the bottom of the product refining tower is 105 ℃, and the reflux ratio is 10: 1. The mixture of the tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and the product tert-butyl acetate is obtained at the tower bottom; the mixture of the tertiary butyl acetate, the C8 and the tertiary butanol obtained from the top of the product refining tower is sent into an extraction tower, the extraction tower is a packed tower, the number of theoretical plates of the extraction tower is 30, the operation conditions of the extraction tower are normal temperature and normal pressure, and the volume ratio of the extractant water to the mixture containing the C8, the tertiary butyl acetate, the tertiary butanol and the water obtained from the top of the refining tower sent into the extraction tower is 5: 1. C8, extracting tert-butyl acetate from the top of the extraction tower, and extracting a mixture of tert-butyl alcohol and water from the bottom of the extraction tower; and (2) feeding a mixture of tert-butyl alcohol and water extracted from the bottom of the extraction tower into a rectifying tower for separation, wherein the operating conditions of the rectifying tower are normal pressure, the temperature of the top of the tower is 82 ℃, the temperature of the bottom of the tower is 110 ℃, and the reflux ratio is 10: 1. the tertiary butanol containing water is extracted from the top of the tower and then directly sent into the esterification reactor for recycling, and the water is extracted from the bottom of the tower and then sent into the extraction tower for recycling.

Through chromatographic analysis, the purity of the tert-butyl acetate product at the bottom of the product refining tower reaches 99.96%, the content of tert-butyl alcohol in the aqueous solution of tert-butyl alcohol obtained at the top of the rectifying tower is 88.56%, the selectivity of tert-butyl acetate reaches 99.82%, the yield reaches 95.33%, and the recovery rate of tert-butyl alcohol reaches 99.67%.

Example 9

The same reaction conditions and separation conditions as those in example 6 were adopted, except that the temperature of the reactor was not controlled in stages, the temperature in the middle of the reactor was controlled at 23 ℃, the tert-butyl acetate product and the aqueous solution of tert-butanol were obtained after reaction separation, the purity of the tert-butyl acetate product at the bottom of the product refining column was 99.12% by chromatographic analysis, the tert-butanol content in the aqueous solution of tert-butanol obtained at the top of the rectifying column was 75.21%, the selectivity of tert-butyl acetate was 92.41%, the yield was 91.23%, and the recovery rate of tert-butanol was 99.56%.

Comparative example 1

Sending acetic acid and isobutene into an esterification reactor, adding a polymerization inhibitor tert-butyl alcohol, reacting under the esterification reaction condition, dividing the esterification reactor into 2 sections, respectively controlling the reaction temperature, controlling the temperature of the first section of reaction to be 18 ℃, controlling the temperature of the second section of reactor to be 18 ℃, controlling the reaction pressure to be 0.6MPa, controlling the acid-olefin ratio to be 3:1, and controlling the reaction residence time to be 80min, wherein the addition amount of the polymerization inhibitor tert-butyl alcohol is 10 wt% of the addition amount of the acetic acid. The content of the mixture obtained after the reaction was: 20.45 wt% of tertiary butyl acetate, 5.12 wt% of tertiary butyl alcohol, 68.54 wt% of acetic acid, C82.12wt%, 2.55 wt% of isobutene and 1.22 wt% of water, feeding the reacted mixture into a light component removal tower for separation, wherein the tower top pressure of the light component removal tower is normal pressure, the tower top temperature is-10 ℃, the tower bottom temperature is 105 ℃, and the reflux ratio is 1: 1. unreacted C4 component is obtained at the top of the tower, and a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the bottom of the tower. Sending a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol obtained at the bottom of the light component removal tower into a de-acetic acid tower for separation, wherein the pressure of the de-acetic acid tower is normal pressure, the temperature of the top of the tower is 80 ℃, the temperature of the bottom of the tower is 115 ℃, and the reflux ratio is 1: 1. A mixture of tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and acetic acid obtained at the tower bottom returns to the esterification reactor for recycling; and (2) feeding the mixture of the tert-butyl acetate, C8 and tert-butyl alcohol obtained at the top of the deacidification tower into a tert-butyl acetate refining tower, wherein the pressure of the tower top of the tert-butyl acetate refining tower is normal pressure, the temperature of the tower top is 80 ℃, the temperature of the tower bottom is 95 ℃, and the reflux ratio is 1: 1. The mixture of the tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the top of the tower, and the product tert-butyl acetate is obtained at the bottom of the tower. And (2) carrying out common rectification separation on the mixed ester of the tert-butyl acetate, C8, tert-butyl alcohol and water extracted from the top of the tert-butyl acetate refining tower, wherein the content of C8 in the mixed ester is 24.00 wt%, the content of the tert-butyl acetate is 28.5 wt%, the content of the tert-butyl alcohol is 45.92 wt%, and the content of the water is 1.58%. The tower top material contains water, C8, tert-butyl alcohol and tert-butyl acetate, the tower bottom material is returned to the reactor for cyclic utilization, the mixture of water, C8, tert-butyl alcohol and tert-butyl acetate obtained from the tower top contains 61.56 wt% of tert-butyl alcohol, and the tert-butyl alcohol yield is calculated to be 62.47%.

Comparative example 2

Sending acetic acid and isobutene into an esterification reactor, adding a polymerization inhibitor tert-butyl alcohol, reacting under the esterification reaction condition, dividing the esterification reactor into 2 sections, respectively controlling the reaction temperature, controlling the temperature of the first section of reaction to be 18 ℃, controlling the temperature of the second section of reactor to be 18 ℃, controlling the reaction pressure to be 0.6MPa, controlling the acid-olefin ratio to be 3:1, and controlling the reaction residence time to be 80min, wherein the addition amount of the polymerization inhibitor tert-butyl alcohol is 10 wt% of the addition amount of the acetic acid. The content of the mixture obtained after the reaction was: 20.45 wt% of tertiary butyl acetate, 5.12 wt% of tertiary butyl alcohol, 68.54 wt% of acetic acid, C82.12wt%, 2.55 wt% of isobutene and 1.22 wt% of water, feeding the reacted mixture into a light component removal tower for separation, wherein the tower top pressure of the light component removal tower is normal pressure, the tower top temperature is-10 ℃, the tower bottom temperature is 105 ℃, and the reflux ratio is 1: 1. unreacted C4 component is obtained at the top of the tower, and a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the bottom of the tower. Sending a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol obtained at the bottom of the light component removal tower into a de-acetic acid tower for separation, wherein the pressure of the de-acetic acid tower is normal pressure, the temperature of the top of the tower is 80 ℃, the temperature of the bottom of the tower is 115 ℃, and the reflux ratio is 1: 1. A mixture of tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and acetic acid obtained at the tower bottom returns to the esterification reactor for recycling; and (2) feeding the mixture of the tert-butyl acetate, C8 and tert-butyl alcohol obtained at the top of the deacidification tower into a tert-butyl acetate refining tower, wherein the pressure of the tower top of the tert-butyl acetate refining tower is normal pressure, the temperature of the tower top is 80 ℃, the temperature of the tower bottom is 95 ℃, and the reflux ratio is 1: 1. The mixture of the tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the top of the tower, and the product tert-butyl acetate is obtained at the bottom of the tower. And (2) carrying out common rectification separation on the mixed ester of the tert-butyl acetate, C8, tert-butyl alcohol and water extracted from the top of the tert-butyl acetate refining tower, wherein the content of C8 in the mixed ester is 18.61%, the content of the tert-butyl acetate is 22.64%, the content of the tert-butyl alcohol is 56.65% and the content of the water is 2.10%. The tower top material contains water, C8, tert-butyl alcohol and tert-butyl acetate, the tower bottom material is returned to the reactor for cyclic utilization, the mixture of water, C8, tert-butyl alcohol and tert-butyl acetate obtained from the tower top contains 62.32 wt% of tert-butyl alcohol, and the tert-butyl alcohol yield is 60.75% by calculation.

Comparative example 3

Sending acetic acid and isobutene into an esterification reactor, adding a polymerization inhibitor tert-butyl alcohol, reacting under the esterification reaction condition, dividing the esterification reactor into 2 sections, respectively controlling the reaction temperature, controlling the temperature of the first section of reaction to be 18 ℃, controlling the temperature of the second section of reactor to be 18 ℃, controlling the reaction pressure to be 0.6MPa, controlling the acid-olefin ratio to be 3:1, and controlling the reaction residence time to be 80min, wherein the addition amount of the polymerization inhibitor tert-butyl alcohol is 10 wt% of the addition amount of the acetic acid. The content of the mixture obtained after the reaction was: 20.45 wt% of tertiary butyl acetate, 5.12 wt% of tertiary butyl alcohol, 68.54 wt% of acetic acid, C82.12wt%, 2.55 wt% of isobutene and 1.22 wt% of water, feeding the reacted mixture into a light component removal tower for separation, wherein the tower top pressure of the light component removal tower is normal pressure, the tower top temperature is-10 ℃, the tower bottom temperature is 105 ℃, and the reflux ratio is 1: 1. unreacted C4 component is obtained at the top of the tower, and a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the bottom of the tower. Sending a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol obtained at the bottom of the light component removal tower into a de-acetic acid tower for separation, wherein the pressure of the de-acetic acid tower is normal pressure, the temperature of the top of the tower is 80 ℃, the temperature of the bottom of the tower is 115 ℃, and the reflux ratio is 1: 1. A mixture of tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the tower top, and acetic acid obtained at the tower bottom returns to the esterification reactor for recycling; and (2) feeding the mixture of the tert-butyl acetate, C8 and tert-butyl alcohol obtained at the top of the deacidification tower into a tert-butyl acetate refining tower, wherein the pressure of the tower top of the tert-butyl acetate refining tower is normal pressure, the temperature of the tower top is 80 ℃, the temperature of the tower bottom is 95 ℃, and the reflux ratio is 1: 1. The mixture of the tert-butyl acetate, C8 and tert-butyl alcohol is obtained at the top of the tower, and the product tert-butyl acetate is obtained at the bottom of the tower. And (2) carrying out common rectification separation on the mixed ester of the tert-butyl acetate, C8, tert-butyl alcohol and water extracted from the top of the tert-butyl acetate refining tower, wherein the content of C8 in the mixed ester is 22.10%, the content of the tert-butyl acetate is 33.95%, the content of the tert-butyl alcohol is 41.15%, and the content of the water is 2.80%. The tower top material contains water, C8, tert-butyl alcohol and tert-butyl acetate, the tower bottom material is returned to the reactor for cyclic utilization, the mixture of water, C8, tert-butyl alcohol and tert-butyl acetate obtained from the tower top contains 67.04 wt% of tert-butyl alcohol, and the mixture is sent to a mixed ester tank, and the yield of tert-butyl alcohol is 58.48% by calculation.

Claims

1. A process for preparing tert-butyl acetate, comprising: (1) sending acetic acid and isobutene or a mixture C4 containing isobutene into an esterification reactor, adding a polymerization inhibitor tert-butyl alcohol, and reacting under esterification reaction conditions; (2) sending the mixture obtained after the reaction into a light component removal tower for separation, obtaining an unreacted C4 component at the tower top, and obtaining a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol at the tower bottom; (3) sending a mixture of acetic acid, tert-butyl acetate, C8 and tert-butyl alcohol obtained at the bottom of the light component removal tower into a de-acetic acid tower for separation, obtaining a mixture of tert-butyl acetate, C8 and tert-butyl alcohol at the top of the tower, and obtaining acetic acid at the bottom of the tower; (4) feeding the mixture of tert-butyl acetate, C8 and tert-butyl alcohol obtained from the tower top of the deacidification tower into a product refining tower for refining, obtaining the mixture of tert-butyl acetate, C8 and tert-butyl alcohol from the tower top, and obtaining the product of tert-butyl acetate from the tower bottom; (5) sending a mixture of tert-butyl acetate, C8 and tert-butyl alcohol obtained from the top of the product refining tower into an extraction tower for extraction, extracting C8 and tert-butyl acetate from the top of the extraction tower, and extracting a mixture of tert-butyl alcohol and water from the bottom of the extraction tower; (6) and (3) feeding a mixture of the tertiary butanol extracted from the bottom of the extraction tower and water into a rectifying tower for separation, extracting the tertiary butanol containing water from the top of the tower, and extracting the water from the bottom of the tower.

2. The method of claim 1, wherein: the esterification reactor is divided into 2 sections, the reaction temperature is controlled at 18-25 ℃ respectively, the temperature of the first section is controlled at 18-30 ℃, and the temperature difference between the first section (usually the lower half section) and the second section (usually the upper half section) is less than or equal to 5 ℃, preferably less than 4 ℃, more preferably less than 3 ℃, and further preferably less than 0 ℃.

3. The method according to claim 1 or 2, characterized in that: the reaction conditions of the esterification reactor are as follows: the reaction pressure is 0.6-1.2MPa, the acid-olefin ratio is 3-10:1, the reaction residence time is 15-80min, and the addition amount of the polymerization inhibitor tert-butyl alcohol is 1-10 wt% of the addition amount of the acetic acid.

4. The method according to any one of claims 1-3, characterized in that: the tower top pressure of the light component removal tower is normal pressure, the tower top temperature is-10-10 ℃, the tower bottom temperature is 105-125 ℃, and the reflux ratio is 1-10: 1.

5. the method according to any one of claims 1-4, characterized in that: the tower top pressure of the acetic acid removing tower is normal pressure, the tower top temperature is 80-100 ℃, the tower bottom temperature is 115-125 ℃, and the reflux ratio is 1-10: 1.

6. The method according to any one of claims 1-5, characterized in that: the top pressure of the product refining tower is normal pressure, the temperature of the top of the product refining tower is 80-90 ℃, the temperature of the bottom of the product refining tower is 95-105 ℃, and the reflux ratio is 1-10: 1.

7. The method according to any one of claims 1-6, characterized in that: the extraction tower is a packed tower, the theoretical plate number of the extraction tower is 5-30 blocks, preferably 5-20 blocks, more preferably 5-15 blocks, and further preferably 5-12 blocks, the operation condition of the extraction tower is normal temperature and normal pressure, and the volume ratio of the extractant water to the mixture containing C8, tert-butyl acetate, tert-butyl alcohol and water obtained from the top of the refining tower fed into the extraction tower is 2-5:1, preferably 2.5-4.5:1, and more preferably 3-4: 1.

8. The method according to any one of claims 1-7, characterized in that: the operating conditions of the rectifying tower are normal pressure, the temperature of the top of the tower is 70-82 ℃, the temperature of the bottom of the tower is 90-110 ℃, and the reflux ratio is 1-10: 1.

9. the method according to any one of claims 1-8, characterized in that: the tertiary butanol containing water extracted from the top of the rectifying tower is directly sent to the esterification reactor for cyclic utilization, and the water extracted from the bottom of the rectifying tower is sent to the extraction tower for cyclic utilization.

10. A device for preparing tert-butyl acetate is characterized by comprising a reactor, a light component removal tower, an acetic acid removal tower, a product refining tower, an extraction tower and a rectification tower which are sequentially connected, wherein the light component removal tower, the acetic acid removal tower, the product refining tower and the rectification tower respectively comprise a tower top condenser, a reflux tank, a tower bottom reboiler, a feed inlet, a tower top discharge outlet and a tower bottom discharge outlet, the esterification reactor is provided with a feed inlet and a discharge outlet, the extraction tower is provided with a water inlet, a feed inlet and a discharge outlet, the discharge outlet of the esterification reactor is connected with the feed inlet of the light component removal tower through a pipeline, the tower bottom discharge outlet of the light component removal tower is connected with the feed inlet of the acetic acid removal tower through a pipeline, the ejection port of the acetic acid removal tower is connected with the tower top reflux tank through a pipeline, the discharge outlet of the tower top reflux tank is connected with the feed inlet of the product refining tower through a pipeline, the discharge hole of the tower top reflux tank is connected with the feed inlet of the extraction tower through a pipeline, and the discharge hole of the tower bottom of the extraction tower is connected with the feed inlet of the rectification tower through a pipeline;

preferably, a discharge port at the bottom of the acetic acid removal tower is connected with a feed port of the esterification reactor through a pipeline; and/or the discharge port at the top of the rectifying tower is connected with the material inlet of the esterification reactor through a pipeline;

further preferably, the water outlet at the bottom of the rectifying tower is connected with the water inlet of the extraction tower through a pipeline.