Tetrahydrofuran purification device and tetrahydrofuran purification method

Abstract

The embodiment of the invention provides a tetrahydrofuran purification device and a tetrahydrofuran purification method, the tetrahydrofuran purification device comprises a normal pressure rectifying tower, pervaporation equipment and a pressurized rectifying tower, and the pervaporation equipment is connected between the normal pressure rectifying tower and the pressurized rectifying tower. Therefore, the use amount of the high-pressure steam can be reduced, the energy consumption of the high-pressure steam can be reduced, the operation cost can be reduced, the operation load of the pressurized rectifying tower can be reduced, and the load upper limit of the tetrahydrofuran purification device can be improved. In addition, the pervaporation equipment is positioned at the front end of the pressurized rectifying tower, so that the influence of the pressurized rectifying tower on the pervaporation equipment is reduced, the stability of the pervaporation equipment is improved, and the dehydration efficiency of the pervaporation equipment is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of tetrahydrofuran purification, and more particularly, to a purification device for tetrahydrofuran and a purification method for tetrahydrofuran. Background Art

[0002] The purification device for tetrahydrofuran can dehydrate and purify the raw material of water-containing tetrahydrofuran to obtain a high-purity tetrahydrofuran product. However, the purification device for tetrahydrofuran in the related art needs to use a large amount of high-pressure steam, resulting in a high operating cost of the purification device for tetrahydrofuran. Summary of the Invention

[0003] Embodiments of the present invention provide a purification device for tetrahydrofuran and a purification method for tetrahydrofuran to solve the above technical problems.

[0004] Embodiments of the present invention achieve the above object through the following technical solutions.

[0005] In a first aspect, embodiments of the present invention provide a purification device for tetrahydrofuran. The purification device for tetrahydrofuran includes an atmospheric distillation column, a pervaporation device, and a pressurized distillation column. The pervaporation device is connected between the atmospheric distillation column and the pressurized distillation column. The atmospheric distillation column is adapted to preliminarily purify the raw material of water-containing tetrahydrofuran. The pervaporation device is adapted to perform pervaporation dehydration on the crude tetrahydrofuran product processed by the atmospheric distillation column. The pressurized distillation column is adapted to perform deep dehydration on the dehydrated crude tetrahydrofuran product processed by the pervaporation device.

[0006] In some embodiments, the atmospheric distillation column is provided with an atmospheric draw-off outlet and a first reflux inlet. The pervaporation device is provided with a pervaporation inlet, a pervaporation draw-off outlet, and a pervaporation discharge outlet. The pressurized distillation column is provided with a pressurization inlet. The atmospheric draw-off outlet is connected to the pervaporation inlet. The pervaporation draw-off outlet is connected to the pressurization inlet. The pervaporation discharge outlet is connected to the first reflux inlet.

[0007] In some embodiments, the atmospheric distillation column is provided with an atmospheric draw-off outlet and a second reflux inlet. The pervaporation device is provided with a pervaporation inlet and a pervaporation draw-off outlet. The pressurized distillation column is provided with a pressurization inlet and a reflux outlet. The atmospheric draw-off outlet is connected to the pervaporation inlet. The pervaporation draw-off outlet is connected to the pressurization inlet. The reflux outlet is connected to the second reflux inlet.

[0008] In some embodiments, the pervaporation device is provided with a pervaporation discharge outlet. The purification device for tetrahydrofuran includes a waste discharge pipeline, a liquid discharge pipeline, and a vacuum generating device. The waste discharge pipeline is connected to the pervaporation discharge outlet. The vacuum generating device is disposed on the waste discharge pipeline. The liquid discharge pipeline is connected between the waste discharge pipeline and the inlet end of the vacuum generating device.

[0009] Second aspect, an embodiment of the present invention provides a method for purifying tetrahydrofuran. The method for purifying tetrahydrofuran includes: introducing a raw material of water-containing tetrahydrofuran into an atmospheric distillation column for preliminary purification; introducing the crude tetrahydrofuran obtained by the preliminary purification into a pervaporation device for pervaporation dehydration; and introducing the crude dehydrated tetrahydrofuran obtained after the pervaporation dehydration into a pressurized distillation column for deep dehydration.

[0010] In some embodiments, introducing the raw material of water-containing tetrahydrofuran into an atmospheric distillation column for preliminary purification includes:

[0011] performing preliminary dehydration on the raw material of water-containing tetrahydrofuran; condensing the crude tetrahydrofuran obtained by the preliminary dehydration into a liquid phase, and pressurizing and heating the crude tetrahydrofuran in the liquid phase to a specified pressure and a specified temperature.

[0012] In some embodiments, the specified pressure is 0.1 MPa.G to 0.5 MPa.G, and the specified temperature is 90°C to 130°C.

[0013] In some embodiments, introducing the crude tetrahydrofuran obtained by the preliminary purification into a pervaporation device for pervaporation dehydration includes: performing pervaporation dehydration on the crude tetrahydrofuran obtained by the preliminary purification to obtain a water vapor material; and condensing and refluxing the water vapor material to the atmospheric distillation column.

[0014] In some embodiments, introducing the crude dehydrated tetrahydrofuran obtained after the pervaporation dehydration into a pressurized distillation column for deep dehydration includes: performing deep dehydration on the crude dehydrated tetrahydrofuran obtained after the pervaporation dehydration to obtain highly water-containing tetrahydrofuran; and refluxing the highly water-containing tetrahydrofuran to the atmospheric distillation column.

[0015] Third aspect, an embodiment of the present invention provides a method for purifying tetrahydrofuran. The method for purifying tetrahydrofuran includes performing preliminary dehydration on a raw material of water-containing tetrahydrofuran; condensing the crude tetrahydrofuran obtained by the preliminary dehydration into a liquid phase, and pressurizing and heating the crude tetrahydrofuran in the liquid phase to a specified pressure and a specified temperature; and introducing the crude tetrahydrofuran obtained by the preliminary purification into a pervaporation device for pervaporation dehydration.

[0016] The purification device for tetrahydrofuran and the purification method for tetrahydrofuran provided by the embodiments of the present invention. The pervaporation device of the purification device for tetrahydrofuran is connected between an atmospheric distillation column and a pressurized distillation column. The atmospheric distillation column is suitable for preliminarily purifying the raw material of water-containing tetrahydrofuran. The pervaporation device is suitable for performing pervaporation dehydration on the crude tetrahydrofuran product processed by the atmospheric distillation column. The pressurized distillation column is suitable for performing deep dehydration on the crude dehydrated tetrahydrofuran product processed by the pervaporation device. In this way, the pervaporation device can process the crude tetrahydrofuran product processed by the atmospheric distillation column before the pressurized distillation column. The pervaporation device can achieve dehydration of the crude tetrahydrofuran product without using high-pressure steam, which helps to reduce the situation that a large amount of high-pressure steam is required for the pressurized distillation column to directly process the crude tetrahydrofuran product processed by the atmospheric distillation column, helps to reduce the usage amount of high-pressure steam, helps to reduce the energy consumption of high-pressure steam, helps to reduce the operation cost, and the pervaporation device can process the crude tetrahydrofuran product before the pressurized distillation column, which helps to reduce the operation load of the pressurized distillation column and helps to increase the load upper limit of the purification device for tetrahydrofuran. In addition, the pervaporation device is located at the front end of the pressurized distillation column, which helps to reduce the influence of the pressurized distillation column on the pervaporation device and helps to improve the stability of the pervaporation device. When problems such as attenuation and leakage occur in the pervaporation device, it is convenient to separate the pervaporation device from the pressurized distillation column, thereby reducing the situation that the pervaporation device affects the operation of the purification device for tetrahydrofuran and helping to improve the flexibility of the structural adjustment of the purification device for tetrahydrofuran. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0018] Figure 1 FIG. shows a schematic structural diagram of the purification device for tetrahydrofuran provided by the embodiments of the present invention.

[0019] Figure 2 FIG. shows a schematic flow chart of the purification method for tetrahydrofuran provided by the embodiments of the present invention.

[0020] Figure 3 FIG. shows a schematic flow chart of the purification method for tetrahydrofuran provided by another embodiment of the present invention.

[0021] Figure 4 FIG. shows a schematic flow chart of the purification method for tetrahydrofuran provided by another embodiment of the present invention.

[0022] Figure 5The flowchart of the purification method of tetrahydrofuran provided by another embodiment of the present invention is shown.

[0023] Figure 6 The flowchart of the purification method of tetrahydrofuran provided by another embodiment of the present invention is shown. Detailed Embodiment

[0024] In order to enable those skilled in the art to better understand the solution of the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the embodiments of the present invention.

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0026] Please refer to Figure 1 , an apparatus 100 for purifying tetrahydrofuran is provided in an embodiment of the present invention. The apparatus 100 for purifying tetrahydrofuran includes an atmospheric distillation column 11, a pervaporation device 12, and a pressurized distillation column 13. The pervaporation device 12 is connected between the atmospheric distillation column 11 and the pressurized distillation column 13. The atmospheric distillation column 11 is adapted to preliminarily purify the raw material of water-containing tetrahydrofuran. The pervaporation device 12 is adapted to perform pervaporation dehydration on the crude tetrahydrofuran product processed by the atmospheric distillation column 11. The pressurized distillation column 13 is adapted to perform deep dehydration on the dehydrated crude tetrahydrofuran product processed by the pervaporation device 12.

[0027] In this way, the pervaporation device 12 can process the crude tetrahydrofuran product processed by the atmospheric distillation column 11 before the pressurized distillation column 13. The pervaporation device 12 can achieve dehydration of the crude tetrahydrofuran product without using high-pressure steam, which helps to reduce the situation that a large amount of high-pressure steam is required for the pressurized distillation column 13 to directly process the crude tetrahydrofuran product processed by the atmospheric distillation column 11, helps to reduce the usage amount of high-pressure steam, helps to reduce the energy consumption of high-pressure steam, helps to reduce the operation cost, and the pervaporation device 12 can process the crude tetrahydrofuran product before the pressurized distillation column 13, which helps to reduce the operation load of the pressurized distillation column 13 and helps to increase the load upper limit of the apparatus 100 for purifying tetrahydrofuran.

[0028] In addition, the pervaporation device 12 is located at the front end of the pressurized rectification column 13, which helps to reduce the influence of the pressurized rectification column 13 on the pervaporation device 12, helps to improve the stability of the pervaporation device 12, and helps to improve the dehydration efficiency of the pervaporation device 12. When problems such as attenuation and leakage occur in the pervaporation device 12, it is convenient to separate the pervaporation device 12 from the pressurized rectification column 13, thereby reducing the situation where the pervaporation device 12 affects the operation of the purification device 100 of tetrahydrofuran, and helping to improve the flexibility of the structural adjustment of the purification device 100 of tetrahydrofuran.

[0029] Among them, the atmospheric rectification column 11 includes accessory storage tanks, material transfer pumps, reboilers, preheaters, overhead condensers, reflux pipelines, automatic control valves, instruments and other devices; the pervaporation device 12 includes material transfer pumps, preheaters, heaters, pervaporation membrane modules, automatic control valves, instruments and other devices; the pressurized rectification column 13 includes accessory storage tanks, feed pumps, reboilers, preheaters, overhead condensers, reflux pipelines, automatic control valves, instruments and other devices, which can be specifically set according to actual situations.

[0030] In some embodiments, the atmospheric rectification column 11 is provided with an atmospheric draw-off outlet 111 and a first reflux inlet 112, the pervaporation device 12 is provided with a pervaporation inlet 121, a pervaporation draw-off outlet 122 and a pervaporation discharge outlet 123, the pressurized rectification column 13 is provided with a pressurized inlet 131, the atmospheric draw-off outlet 111 is connected to the pervaporation inlet 121, the pervaporation draw-off outlet 122 is connected to the pressurized inlet 131, and the pervaporation discharge outlet 123 is connected to the first reflux inlet 112.

[0031] In this way, the crude tetrahydrofuran treated by the atmospheric rectification column 11 can enter the pervaporation device 12 through the atmospheric draw-off outlet 111 and the pervaporation inlet 121. The dehydrated crude tetrahydrofuran treated by the pervaporation device 12 can enter the pressurized rectification column 13 through the pervaporation draw-off outlet 122 and the pressurized inlet 131. The water vapor material treated by the pervaporation device 12 can flow back to the atmospheric rectification column 11 through the pervaporation discharge outlet 123 and the first reflux inlet 112 to re-purify the discharged water vapor material, which helps to improve the utilization rate of the water-containing tetrahydrofuran raw material and helps to improve the purification rate of the water-containing tetrahydrofuran raw material.

[0032] Exemplarily, the atmospheric pressure extraction outlet 111 can be provided at the top of the atmospheric pressure rectification column 11. The atmospheric pressure rectification column 11 can also be provided with an atmospheric pressure discharge outlet 114, and the atmospheric pressure discharge outlet 114 is located at the bottom of the atmospheric pressure rectification column 11. The permeation inlet 121 is connected to the atmospheric pressure extraction outlet 111 at the top of the column. The pressurized rectification column 13 can also be provided with a pressurized extraction outlet 133, and the pressurized extraction outlet 133 is located at the bottom of the pressurized rectification column 13. When the purification device 100 of tetrahydrofuran works, the crude tetrahydrofuran after being treated by the atmospheric pressure rectification column 11 flows from the atmospheric pressure extraction outlet 111 at the top of the column to the pervaporation device 12. The dehydrated crude tetrahydrofuran after being treated by the pervaporation device 12 flows from the permeate extraction outlet 122 to the pressurized rectification column 13. The pure tetrahydrofuran after being treated by the pressurized rectification column 13 is extracted from the pressurized extraction outlet 133 at the bottom of the column. The waste liquid after being treated by the atmospheric pressure rectification column 11 is discharged from the atmospheric pressure discharge outlet 114 at the bottom of the column. The water vapor material after being treated by the pervaporation device 12 is refluxed to the atmospheric pressure rectification column 11 through the permeate discharge outlet 123 and the first reflux inlet 112.

[0033] In some embodiments, the atmospheric pressure rectification column 11 is provided with an atmospheric pressure extraction outlet 111 and a second reflux inlet 113. The pervaporation device 12 is provided with a permeation inlet 121 and a permeate extraction outlet 122. The pressurized rectification column 13 is provided with a pressurized inlet 131 and a reflux outlet 132. The atmospheric pressure extraction outlet 111 is connected to the permeation inlet 121. The permeate extraction outlet 122 is connected to the pressurized inlet 131. The reflux outlet 132 is connected to the second reflux inlet 113.

[0034] In this way, the high-water-content tetrahydrofuran after being treated by the pressurized rectification column 13 can be refluxed to the atmospheric pressure rectification column 11 through the reflux outlet 132 and the second reflux inlet 113, so as to re-purify the discharged high-water-content tetrahydrofuran, which helps to improve the utilization rate of the water-containing tetrahydrofuran raw material and helps to improve the purification rate of the water-containing tetrahydrofuran raw material.

[0035] In some embodiments, the pervaporation device 12 is provided with a permeate discharge outlet 123. The purification device 100 of tetrahydrofuran includes a waste discharge pipeline 151, a liquid discharge pipeline 152 and a vacuum generating device 14. The waste discharge pipeline 151 is connected to the permeate discharge outlet 123. The vacuum generating device 14 is arranged on the waste discharge pipeline 151. The liquid discharge pipeline 152 is connected between the waste discharge pipeline 151 and the inlet end of the vacuum generating device 14.

[0036] In this way, the discharged water vapor waste can be treated by the vacuum generating device 14, so that the water vapor waste can be converted into gas through the vacuum generating device 14 to realize the gas-liquid separation of the water vapor waste and facilitate the collection of the water vapor waste.

[0037] Among them, the waste gas in the water vapor waste enters the tail gas treatment system for collection, and the waste liquid in the water vapor waste can enter the buffer pipe for collection, which can be specifically set according to the actual situation.

[0038] Please refer to Figure 2 , an embodiment of the present invention provides a method for purifying tetrahydrofuran. The method for purifying tetrahydrofuran includes step 010, step 020, and step 030.

[0039] Step 010: Introduce the water-containing tetrahydrofuran raw material into the atmospheric distillation column 11 for preliminary purification.

[0040] The atmospheric distillation column 11 can perform preliminary dehydration on the water-containing tetrahydrofuran raw material. The atmospheric distillation column 11 is provided with an atmospheric inlet 115, an atmospheric extraction outlet 111, and an atmospheric discharge outlet 114. The water-containing tetrahydrofuran raw material can enter the atmospheric distillation column 11 from the atmospheric inlet 115. After preliminary purification in the atmospheric distillation column 11, the water-containing tetrahydrofuran raw material will be preliminarily dehydrated, and the crude tetrahydrofuran flows out from the atmospheric extraction outlet 111, and the waste liquid is discharged from the atmospheric discharge outlet 114.

[0041] Step 020: Introduce the crude tetrahydrofuran obtained by preliminary purification into the pervaporation device 12 for pervaporation dehydration.

[0042] The pervaporation device 12 can perform pervaporation dehydration on the crude tetrahydrofuran. The pervaporation device 12 is provided with a pervaporation inlet 121, a pervaporation extraction outlet 122, and a pervaporation discharge outlet 123. The atmospheric extraction outlet 111 is connected to the pervaporation inlet 121. The crude tetrahydrofuran after preliminary purification in the atmospheric distillation column 11 can enter the pervaporation device 12 from the pervaporation inlet 121. After being processed in the pervaporation device 12, the water content of the crude tetrahydrofuran will be greatly reduced, and the processed crude tetrahydrofuran flows out from the pervaporation extraction outlet 122, and the water vapor material is discharged from the pervaporation discharge outlet 123.

[0043] Step 030: Introduce the dehydrated crude tetrahydrofuran obtained after pervaporation dehydration into the pressurized distillation column 13 for deep dehydration.

[0044] The pressurized distillation column 13 can perform deep dehydration on the crude tetrahydrofuran. The pressurized distillation column 13 is provided with a pressurized inlet 131 and a pressurized extraction outlet 133. The pervaporation extraction outlet 122 is connected to the pressurized inlet 131. The crude tetrahydrofuran after pervaporation dehydration in the pervaporation device 12 can enter the pressurized distillation column 13 from the pressurized inlet 131. After deep dehydration in the pressurized distillation column 13, low-water-content tetrahydrofuran is obtained, and the processed low-water-content tetrahydrofuran flows out from the pressurized extraction outlet 133.

[0045] Thus, the crude tetrahydrofuran can enter the pervaporation device 12 for dehydration treatment before the pressurized distillation column 13. The pervaporation device 12 can dehydrate the crude tetrahydrofuran without using high-pressure steam, which helps to reduce the situation where a large amount of high-pressure steam is required for the pressurized distillation column 13 to directly process the crude tetrahydrofuran after being treated by the atmospheric distillation column 11, helps to reduce the usage of high-pressure steam, helps to reduce the energy consumption of high-pressure steam, helps to reduce the operating cost, and also helps to reduce the operating load of the pressurized distillation column 13, and helps to increase the load upper limit of the purification device 100 of tetrahydrofuran.

[0046] In addition, the pervaporation device 12 is located at the front end of the pressurized distillation column 13, which helps to reduce the influence of the pressurized distillation column 13 on the pervaporation device 12, helps to improve the stability of the pervaporation device 12, and helps to improve the dehydration efficiency of the pervaporation device 12. When problems such as attenuation and leakage occur in the pervaporation device 12, it is convenient to separate the pervaporation device 12 from the pressurized distillation column 13, thereby reducing the situation where the pervaporation device 12 affects the operation of the purification device 100 of tetrahydrofuran.

[0047] Please refer to Figure 3 , in some embodiments, introducing the water-containing tetrahydrofuran raw material into the atmospheric distillation column 11 for preliminary purification includes step 011 and step 012, that is, step 010 includes step 011 and step 012.

[0048] Step 011: Preliminarily dehydrate the water-containing tetrahydrofuran raw material.

[0049] Introduce the water-containing tetrahydrofuran raw material into the atmospheric distillation column 11. During the distillation process, the water-containing tetrahydrofuran raw material is heated to the boiling point, and gas and liquid phases are generated by boiling. The water in the water-containing tetrahydrofuran raw material will be distilled out and condensed to the bottom of the column, thereby realizing the preliminary dehydration of the water-containing tetrahydrofuran raw material.

[0050] Among them, the water content range of the water-containing tetrahydrofuran raw material is 6wt% - 40wt%, and the water content range of the crude tetrahydrofuran after being treated by the atmospheric distillation column 11 is 6wt% - 12wt%.

[0051] Step 012: Condense the crude tetrahydrofuran obtained by preliminary dehydration into a liquid phase, and pressurize and heat the liquid-phase crude tetrahydrofuran to a specified pressure and a specified temperature.

[0052] Due to the different volatilities of water and organic substances, by controlling conditions such as the temperature and pressure of the crude tetrahydrofuran, it can be ensured that water is effectively distilled out from the crude tetrahydrofuran.

[0053] In some embodiments, the specified pressure is 0.1MPa.G - 0.5MPa.G, and the specified temperature is 90°C - 130°C.

[0054] In this way, it helps to ensure that the crude tetrahydrofuran can be maintained in a suitable pressure and temperature environment, helps to improve the dehydration efficiency of the crude tetrahydrofuran, helps to reduce the situation where the crude tetrahydrofuran cannot be dehydrated due to insufficient pressure, and also helps to reduce the situation where the crude tetrahydrofuran cannot be dehydrated due to insufficient temperature.

[0055] Among them, the specified pressure can be 0.35 MPa.G, and the specified temperature can be 100 °C; for another example, the specified pressure can be 0.45 MPa.G, and the specified temperature can be 120 °C, and it can be specifically set according to the actual situation.

[0056] Comparative Example 1: 8 t / h of tetrahydrofuran raw material containing 20.00 wt% water was introduced into the atmospheric distillation column 11 for preliminary purification. The crude tetrahydrofuran with a water content of 12 wt% was obtained at the top of the atmospheric distillation column 11. The crude tetrahydrofuran with a water content of 12 wt% obtained at the top of the atmospheric distillation column 11 was condensed into a liquid phase, pressurized to the specified pressure of 0.35 MPa.G, and heated to the specified temperature of 100 °C. Then, the steam after temperature increase and pressure increase was condensed and pressurized to (55 °C, 0.8 MPa.G) and then introduced into the pressurized distillation column 13 for deep dehydration. The water content of the tetrahydrofuran after deep dehydration was 0.02 wt%.

[0057] Example 1: 8 t / h of tetrahydrofuran raw material containing 20.00 wt% water was introduced into the atmospheric distillation column 11 for preliminary purification. The crude tetrahydrofuran with a water content of 12 wt% was obtained at the top of the atmospheric distillation column 11. The crude tetrahydrofuran with a water content of 12 wt% obtained at the top of the atmospheric distillation column 11 was condensed into a liquid phase, pressurized to the specified pressure of 0.35 MPa.G, and heated to the specified temperature of 100 °C. Then, the crude tetrahydrofuran after temperature increase and pressure increase was introduced into the pervaporation device 12 for pervaporation dehydration. During the pervaporation dehydration process, the raw material remained in a liquid phase. The water content of the tetrahydrofuran after pervaporation dehydration was 2.0 wt%. Finally, the dehydrated crude tetrahydrofuran with a water content of 2.0 wt% after pervaporation dehydration was introduced into the pressurized distillation column 13 for deep dehydration. The water content of the tetrahydrofuran after deep dehydration was 0.02 wt%.

[0058] In this way, the pervaporation device 12 can process the crude tetrahydrofuran after being treated by the atmospheric distillation column 11 before the pressurized distillation column 13. The pervaporation device 12 can dehydrate the crude tetrahydrofuran without using high-pressure steam, which helps to reduce the situation that a large amount of high-pressure steam is required for the pressurized distillation column 13 to directly process the crude tetrahydrofuran after being treated by the atmospheric distillation column 11, helps to reduce the usage amount of high-pressure steam, helps to reduce the energy consumption of high-pressure steam, enables Example 1 to reduce the energy consumption by 2.5 t / h compared with Comparative Example 1, helps to reduce the operation cost, and the pervaporation device 12 can process the crude tetrahydrofuran before the pressurized distillation column 13, which helps to reduce the operation load of the pressurized distillation column 13 and helps to increase the load upper limit of the tetrahydrofuran purification device 100. Example 1 can also improve the flexibility of the structure adjustment of the tetrahydrofuran purification device 100 compared with Comparative Example 1 to better meet the production requirements.

[0059] In Example 2, 10 t / h of tetrahydrofuran raw material containing 20.00 wt% water can be introduced into the atmospheric distillation column 11 for preliminary purification. The crude tetrahydrofuran with a water content of 12 wt% is obtained at the top of the atmospheric distillation column 11. The crude tetrahydrofuran with a water content of 12 wt% obtained at the top of the atmospheric distillation column 11 is condensed into a liquid phase and pressurized to the specified pressure of 0.35 MPa.G and heated to the specified temperature of 100 °C. Then, the crude tetrahydrofuran after being heated and pressurized is introduced into the pervaporation device 12 for pervaporation dehydration. During the pervaporation dehydration process, the raw material remains in the liquid phase, and the water content of the tetrahydrofuran after pervaporation dehydration is 3.5 wt%. Finally, the dehydrated crude tetrahydrofuran with a water content of 3.5 wt% after pervaporation dehydration is introduced into the pressurized distillation column 13 for deep dehydration, and the water content of the tetrahydrofuran after deep dehydration is 0.02 wt%.

[0060] In this way, the pervaporation device 12 can process the crude tetrahydrofuran after being treated by the atmospheric distillation column 11 before the pressurized distillation column 13. The pervaporation device 12 can dehydrate the crude tetrahydrofuran without using high-pressure steam, which helps to reduce the situation that a large amount of high-pressure steam is required for the pressurized distillation column 13 to directly process the crude tetrahydrofuran after being treated by the atmospheric distillation column 11, helps to reduce the usage amount of high-pressure steam, helps to reduce the energy consumption of high-pressure steam, enables Example 1 to reduce the energy consumption by 2.5 t / h compared with Comparative Example 1, helps to reduce the operation cost, and the pervaporation device 12 can process the crude tetrahydrofuran before the pressurized distillation column 13, which helps to reduce the operation load of the pressurized distillation column 13 and helps to increase the load upper limit of the tetrahydrofuran purification device 100. Example 2 can also improve the flexibility of the structure adjustment of the tetrahydrofuran purification device 100 compared with Comparative Example 1 to better meet the production requirements.

[0061] Refer to Figure 4, in some embodiments, introducing the crude tetrahydrofuran obtained by preliminary purification into the pervaporation device 12 for pervaporation dehydration includes step 021 and step 022, that is, step 020 includes step 021 and step 022.

[0062] Step 021: Subject the crude tetrahydrofuran obtained by preliminary purification to pervaporation dehydration to obtain a water vapor material.

[0063] After the pervaporation device 12 processes the crude tetrahydrofuran obtained by preliminary purification, a crude dehydrated tetrahydrofuran and a water vapor material are produced. The crude dehydrated tetrahydrofuran can enter the pressurized rectification tower 13 through the pervaporation extraction outlet 122 and the pressurization inlet 131.

[0064] Step 022: Condense the water vapor material and reflux it to the atmospheric rectification tower 11.

[0065] The water vapor material can be condensed by a condenser and refluxed to the atmospheric rectification tower 11 through the pervaporation discharge outlet 123 and the first reflux inlet 112.

[0066] In this way, the discharged water vapor material can be purified again, which helps to improve the utilization rate of the water-containing tetrahydrofuran raw material and helps to improve the purification rate of the water-containing tetrahydrofuran raw material.

[0067] Among them, after the pervaporation device 12 processes the crude tetrahydrofuran obtained by preliminary purification, water vapor waste is also produced. The discharged water vapor waste can be processed by a vacuum generating device 14 so that the water vapor waste can be converted into a gas to separately collect the waste gas and waste liquid in the water vapor waste, which helps to realize the gas-liquid separation of the water vapor waste and facilitates the collection of the water vapor waste.

[0068] Refer to Figure 5 , in some embodiments, introducing the crude dehydrated tetrahydrofuran obtained after pervaporation dehydration into the pressurized rectification tower 13 for deep dehydration includes step 031 and step 032.

[0069] Step 031: Subject the crude dehydrated tetrahydrofuran obtained after pervaporation dehydration to deep dehydration to obtain high-water-content tetrahydrofuran.

[0070] After the pressurized rectification tower 13 processes the crude dehydrated tetrahydrofuran obtained after pervaporation dehydration, low-water-content tetrahydrofuran and high-water-content tetrahydrofuran are produced. The low-water-content tetrahydrofuran can flow out through the pressurized extraction outlet 133.

[0071] Step 032: Reflux the high-water-content tetrahydrofuran to the atmospheric rectification tower 11.

[0072] In this way, the high-water-content tetrahydrofuran can be refluxed to the atmospheric distillation column 11 through the reflux outlet 132 and the second reflux inlet 113, which helps to re-purify the discharged high-water-content tetrahydrofuran, improve the utilization rate of the water-containing tetrahydrofuran raw material, and increase the purification rate of the water-containing tetrahydrofuran raw material.

[0073] Refer to Figure 6 , an embodiment of the present invention provides a method for purifying tetrahydrofuran. The method for purifying tetrahydrofuran includes step 011, step 012, and step 020.

[0074] Step 011: Preliminarily dehydrate the water-containing tetrahydrofuran raw material.

[0075] Step 012: Condense the crude tetrahydrofuran obtained from the preliminary dehydration into a liquid phase, and pressurize and heat the liquid-phase crude tetrahydrofuran to a specified pressure and a specified temperature.

[0076] Step 020: Introduce the crude tetrahydrofuran obtained from the preliminary purification into the pervaporation device 12 for pervaporation dehydration.

[0077] Step 011, step 012, and step 020 are the same as the content of the above embodiment and will not be elaborated here.

[0078] In this way, when the dehydration rate requirement for the water-containing tetrahydrofuran is not high, the pressurized distillation column 13 can be separated from the pervaporation device 12, and the dehydration and purification of the water-containing tetrahydrofuran do not need to pass through the pressurized distillation column 13, which helps to reduce the dehydration path of the water-containing tetrahydrofuran and improve the dehydration efficiency of the water-containing tetrahydrofuran.

[0079] Example 3: When the dehydration rate requirement for the water-containing tetrahydrofuran is not high, 8 t / h of the tetrahydrofuran raw material containing 20.00 wt% water can be introduced into the atmospheric distillation column 11 for preliminary purification. The crude tetrahydrofuran with a water content of 12 wt% is obtained at the top of the atmospheric distillation column 11. The crude tetrahydrofuran with a water content of 12 wt% obtained at the top of the atmospheric distillation column 11 is condensed into a liquid phase, pressurized to a specified pressure of 0.45 MPa.G, and heated to a specified temperature of 120 °C. Then, the crude tetrahydrofuran after heating and pressurization is introduced into the pervaporation device 12 for pervaporation dehydration. The water content of the tetrahydrofuran after pervaporation dehydration is 1.0 wt%, thus realizing the dehydration of the water-containing tetrahydrofuran.

[0080] In this way, when the production demand changes, the pressurized distillation column 13 can be separated from the pervaporation device 12, and the product can be directly withdrawn through the atmospheric distillation column 11 and the pervaporation device 12. The operation is simple, which helps to reduce energy consumption. Example 3 can be conveniently adjusted relative to Comparative Example 1 to better meet the actual production needs.

[0081] In summary, for the purification device 100 of tetrahydrofuran and the purification method of tetrahydrofuran provided by the embodiments of the present invention, the pervaporation device 12 of the purification device 100 of tetrahydrofuran is connected between the atmospheric distillation column 11 and the pressurized distillation column 13. The atmospheric distillation column 11 is suitable for preliminarily purifying the raw material of water-containing tetrahydrofuran. The pervaporation device 12 is suitable for pervaporation dehydration of the crude tetrahydrofuran product processed by the atmospheric distillation column 11. The pressurized distillation column 13 is suitable for deep dehydration of the crude dehydrated tetrahydrofuran product processed by the pervaporation device 12. In this way, the pervaporation device 12 can process the crude tetrahydrofuran product processed by the atmospheric distillation column 11 before the pressurized distillation column 13. The pervaporation device 12 can realize dehydration of the crude tetrahydrofuran product without using high-pressure steam, which helps to reduce the situation that a large amount of high-pressure steam is required for the pressurized distillation column 13 to directly process the crude tetrahydrofuran product processed by the atmospheric distillation column 11, helps to reduce the usage amount of high-pressure steam, helps to reduce the energy consumption of high-pressure steam, helps to reduce the operation cost, and the pervaporation device 12 can process the crude tetrahydrofuran product before the pressurized distillation column 13, which helps to reduce the operation load of the pressurized distillation column 13 and helps to increase the load upper limit of the purification device 100 of tetrahydrofuran. In addition, the pervaporation device 12 is located at the front end of the pressurized distillation column 13, which helps to reduce the influence of the pressurized distillation column 13 on the pervaporation device 12, helps to improve the stability of the pervaporation device 12, and helps to improve the dehydration efficiency of the pervaporation device 12. When problems such as attenuation and leakage occur in the pervaporation device 12, it is convenient to separate the pervaporation device 12 from the pressurized distillation column 13, so as to reduce the situation that the pervaporation device 12 affects the operation of the purification device 100 of tetrahydrofuran, and helps to improve the flexibility of the structural adjustment of the purification device 100 of tetrahydrofuran.

[0082] In the embodiments of the present invention, unless otherwise clearly specified or limited, terms such as "assembly" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or indirectly connected through an intermediate medium, or the communication inside two components, or only surface contact, or surface contact connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0083] In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and should not be construed as specific or special structures. The description of "some embodiments" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In the embodiments of the present invention, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in the embodiments of the present invention and the features of different embodiments or examples.

[0084] The above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention, rather than to limit them; although the embodiments of the present invention have been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the embodiments of the present invention.

Claims

1. A tetrahydrofuran purification device, characterized in that, include: An atmospheric distillation tower, a pervaporation device and a pressurized distillation tower, wherein the pervaporation device is connected between the atmospheric distillation tower and the pressurized distillation tower, the atmospheric distillation tower is suitable for preliminarily purifying a water-containing tetrahydrofuran raw material, the pervaporation device is suitable for pervaporating and dehydrating a crude tetrahydrofuran product treated by the atmospheric distillation tower, and the pressurized distillation tower is suitable for deeply dehydrating the dehydrated crude tetrahydrofuran product treated by the pervaporation device.

2. The purification device of tetrahydrofuran according to claim 1, wherein the atmospheric distillation tower is provided with an atmospheric extraction outlet and a first reflux inlet, the pervaporation equipment is provided with a permeate inlet, a permeate extraction outlet and a permeate discharge outlet, the pressurized distillation tower is provided with a pressurized inlet, the atmospheric extraction outlet is connected to the permeate inlet, the permeate extraction outlet is connected to the pressurized inlet, and the permeate discharge outlet is connected to the first reflux inlet.

3. The purification device for tetrahydrofuran according to claim 1, characterized in that, The atmospheric distillation tower is provided with an atmospheric production outlet and a second reflux inlet, the pervaporation equipment is provided with a permeate inlet and a permeate production outlet, the pressurized distillation tower is provided with a pressurized inlet and a reflux outlet, the atmospheric production outlet is connected to the permeate inlet, the permeate production outlet is connected to the pressurized inlet, and the reflux outlet is connected to the second reflux inlet.

4. The purification device for tetrahydrofuran according to claim 1, characterized in that, The pervaporation equipment is provided with a permeate outlet, and the tetrahydrofuran purification device comprises a waste discharge pipe, a liquid discharge pipe and a vacuum generating device, wherein the waste discharge pipe is connected to the permeate outlet, the vacuum generating device is arranged in the waste discharge pipe, and the liquid discharge pipe is connected between the waste discharge pipe and the inlet end of the vacuum generating device.

5. A method for purifying tetrahydrofuran, characterized in that: include: The aqueous tetrahydrofuran raw material is introduced into an atmospheric distillation tower for preliminary purification; The crude tetrahydrofuran obtained by preliminary purification is introduced into a pervaporation device for pervaporation dehydration; The crude dehydrated tetrahydrofuran obtained after pervaporation dehydration is introduced into a pressure distillation tower for deep dehydration.

6. The method for purifying tetrahydrofuran according to claim 5, characterized in that The step of introducing the aqueous tetrahydrofuran raw material into an atmospheric distillation tower for preliminary purification comprises: The aqueous tetrahydrofuran raw material is initially dehydrated; The crude tetrahydrofuran obtained by preliminary dehydration is condensed into a liquid phase, and the liquid phase crude tetrahydrofuran is pressurized and heated to a specified pressure and a specified temperature.

7. The method for purifying tetrahydrofuran according to claim 6, wherein The specified pressure is 0.1 MPa.G to 0.5 MPa.G, and the specified temperature is 90°C to 130°C.

8. The method for purifying tetrahydrofuran according to claim 5, characterized in that, The step of introducing the crude tetrahydrofuran obtained by preliminary purification into a pervaporation device for pervaporation dehydration comprises: The crude tetrahydrofuran product obtained by preliminary purification is subjected to pervaporation dehydration to obtain a water vapor material; The water vapor is condensed and refluxed to the atmospheric distillation tower.

9. The method for purifying tetrahydrofuran according to claim 5, characterized in that: The step of introducing the dehydrated tetrahydrofuran crude product obtained after pervaporation dehydration into a pressurized distillation tower for deep dehydration comprises: Deeply dehydrating the crude tetrahydrofuran dehydrate obtained after pervaporation dehydration to obtain highly water-containing tetrahydrofuran; The highly water-containing tetrahydrofuran is refluxed to the atmospheric distillation tower.

10. A method for purifying tetrahydrofuran, characterized in that: include: The aqueous tetrahydrofuran raw material is initially dehydrated; Condensing the crude tetrahydrofuran obtained by preliminary dehydration into a liquid phase, and pressurizing and heating the crude tetrahydrofuran in the liquid phase to a specified pressure and a specified temperature; The crude tetrahydrofuran obtained through preliminary purification is introduced into a pervaporation device for pervaporation dehydration.

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