Purification system and method of isopropanol

Abstract

The invention relates to the field of preparation of wet electronic chemicals required in a semiconductor manufacturing process, and discloses an isopropanol purification system which comprises an isopropanol purification unit and a waste liquid recovery unit, the isopropanol purification unit comprises a light component removal subunit, a dehydration subunit, a heavy component removal subunit, a de-ionization subunit and a micro-particle removal unit which are sequentially communicated in series along the material flow direction, and is used for sequentially carrying out light component removal, dehydration, heavy component removal, de-ionization and micro-particle removal on an isopropanol raw material to obtain purified isopropanol; wherein the step of removing light components from the isopropanol raw material comprises the step of removing light components containing acetone; the waste liquid recovery unit comprises a light component recovery subunit, and the light component recovery subunit is communicated with the light component removal subunit. The method has the advantages of good stability, high product recovery rate compared with the traditional process, high product purity, low water content and low metal ion residue, and can be used in the integrated circuit industry.

Description

Technical Field

[0001] The invention relates to a preparation technology of high-end wet electronic chemicals for integrated circuits (ICs), and in particular to a purification system and method for isopropyl alcohol. Background Art

[0002] Ultra-clean high-purity reagents are special chemicals used in the manufacturing process of large-scale integrated circuits (ICs) and high-end semiconductor devices. They are mainly used in the cleaning, photolithography, and etching processes of silicon single wafers. Their purity and cleanliness have an important impact on the yield, electrical properties, and reliability of integrated circuits.

[0003] Ultra-clean high-purity isopropyl alcohol is an important wet electronic chemical and the most widely used organic wet electronic chemical. It is often used as a cleaning agent and desiccant for the final cleaning of silicon wafers. Therefore, its product quality has a crucial impact on the yield rate of integrated circuits. As ultra-clean high-purity isopropyl alcohol, it has extremely strict requirements on product purity, organic impurities, water content, anions, cations and particulate matter residues. The higher the quality of the integrated circuit, the more stringent the requirements for the above indicators.

[0004] With the development of the domestic integrated circuit industry, the preparation method of ultra-clean high-purity isopropyl alcohol has also received certain attention. There are some related reports, such as CN 111517917A reports a production system of electronic-grade isopropyl alcohol, including a raw material delivery unit, a molecular sieve adsorption unit, an evaporation tank, a first distillation unit, a second distillation unit and a filtering unit. Also, CN114870420 A discloses a high-purity electronic-grade isopropyl alcohol production method and device, including a dehydration processor, a microfilter, an anion and cation remover, distillation and nanofiltration steps. The removal techniques of organic impurities in the product in the prior art are relatively similar, and the removal of organic impurities is carried out by multi-stage distillation for many times. However, this technique is less effective in the removal of some organic impurities, and it is easy to cause the preparation recovery rate of ultra-clean high-purity isopropyl alcohol to be lower at the same time, which greatly affects the product stability production and the economic production efficiency of the enterprise.

[0005] Based on the analysis of the currently reported ultra-clean high-purity isopropyl alcohol preparation processes, it has become an urgent issue to develop an ultra-clean high-purity isopropyl alcohol preparation system with good organic impurity removal effect, stable product quality and high recovery rate. Summary of the invention

[0006] The purpose of the present invention is to overcome the problems of low recovery rate, high energy consumption and poor product grade in the prior art, and to provide an isopropyl alcohol purification system and method, which has the advantages of simple operation, energy saving, high recovery rate and the ability to produce high-quality ultra-clean high-purity isopropyl alcohol.

[0007] In order to achieve the above object, the present invention provides a purification system for isopropanol on one hand, the purification system comprising:

[0008] The isopropyl alcohol purification unit comprises a light removal unit, a water removal unit, a heavy removal unit, an ion removal unit and a micron removal unit which are sequentially connected in series along the material flow direction, so as to sequentially remove light, water, heavy, ion and micron from the isopropyl alcohol raw material to obtain purified isopropyl alcohol;

[0009] Wherein, the isopropanol raw material light removal includes removing light components including acetone;

[0010] The waste liquid recovery unit comprises a light component recovery subunit, which is connected to the light component removal unit so that the light component can enter the light component recovery unit, convert the acetone in the light component into isopropanol and then return to the light component removal unit.

[0011] A second aspect of the present invention provides a method for purifying isopropanol, characterized in that the purification method adopts the isopropanol purification system of the present invention, comprising:

[0012] Feeding an isopropyl alcohol raw material into a light component removal unit, so that the isopropyl alcohol raw material is sequentially subjected to light component removal, dehydration, heavy component removal, deionization and particle removal to obtain purified isopropyl alcohol; wherein the light component removal of the isopropyl alcohol raw material includes removing light components including acetone;

[0013] The acetone in the light component is converted into isopropanol, and the isopropanol is returned to the delightening unit.

[0014] Through the above technical scheme, the isopropanol purification system provided by the present invention can obtain a high-grade ultra-clean high-purity isopropanol product, which has the advantages of high preparation recovery rate and efficiency, stable product, simple operation, and can realize continuous production. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of a system for purifying isopropanol according to one embodiment.

[0016] Description of Reference Numerals

[0017] ①De-lightness tower ②De-lightness tower top heat exchanger

[0018] ③De-light tower kettle heat exchanger ④Liquid pressure reducer I

[0019] ⑤Light component enrichment tower ⑥Light component enrichment tower top heat exchanger

[0020] ⑦Compressor⑧Catalytic hydrogenation unit

[0021] ⑨Hydrogen compressor ⑩Gas-liquid separator

[0022] Liquid Pressure Regulator II Degravity tower kettle heat exchanger

[0023] Dehydration adsorption device Deweighting tower

[0024] Degravity tower top heat exchanger Heavy component enrichment tower

[0025] Heavy component enrichment tower top heat exchanger Heavy component enrichment tower kettle heat exchanger

[0026] Ion exchange adsorption device Membrane separation device

[0027] 1Isopropanol raw material feed pipeline 2Light component discharge pipeline

[0028] 6 Feed inlet of light component enrichment tower 7 Top extraction pipe of light component enrichment tower

[0029] 8. Top reflux pipe of light component enrichment tower 9. Acetone pipeline

[0030] 10 Bottom lateral feed port 12 Gas phase outlet of gas-liquid separator

[0031] 13 Hydrogen feed pipeline 16 Light component enrichment tower bottom reflux pipeline 17 Light component enrichment tower kettle extraction pipeline 18 Liquid phase outlet of gas-liquid separator

[0032] 19 Removal of lightness tower kettle discharge pipeline 20 Removal of lightness tower kettle reflux pipe

[0033] 25 Reflux pipe at the top of the de-weighting tower 26 Production line at the top of the de-weighting tower

[0034] 27 Heavy fraction discharge pipeline of de-weighting tower 28 Reflux pipe of kettle of de-weighting tower

[0035] 29 The top reflux pipe of the heavy component enrichment tower 30 The top extraction pipeline of the heavy component enrichment tower

[0036] 31 Heavy component enrichment tower kettle reflux liquid pipeline 32 Heavy component enrichment tower kettle produced liquid pipeline

[0037] 35 Ultra-clean high-purity isopropyl alcohol products DETAILED DESCRIPTION

[0038] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0039] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0040] In the present invention, unless otherwise specified, directional words such as "up, down, left, right" generally refer to up, down, left, right as shown in the reference drawings; "inside and outside" refer to inside and outside relative to the outline of each component itself.

[0041] The present invention discloses a purification system of isopropanol, such as Figure 1 As shown, the purification system includes:

[0042] The isopropyl alcohol purification unit comprises a light removal unit, a water removal unit, a heavy removal unit, an ion removal unit and a micron removal unit which are sequentially connected in series along the material flow direction, so as to sequentially remove light, water, heavy, ion and micron from the isopropyl alcohol raw material to obtain purified isopropyl alcohol;

[0043] Wherein, the light removal of the isopropanol raw material includes removing light components including acetone;

[0044] The waste liquid recovery unit includes a light component recovery subunit, which is connected to the light component removal unit so that the light component can enter the light component recovery unit, convert the acetone in the light component into isopropanol and then return to the light component removal unit.

[0045] The isopropanol purification system of the present invention can effectively prepare a high-grade ultra-clean high-purity isopropanol product, and has the advantages of high preparation recovery rate and efficiency, stable product, simple operation, and ability to realize continuous production.

[0046] In some embodiments of the present invention, the light component recovery subunit comprises a light component enrichment tower ⑤, a catalytic hydrogenation device ⑧ and a gas-liquid separator ⑩ which are connected in series in sequence, wherein:

[0047] The purpose of the light component enrichment tower ⑤ is to remove and further concentrate the light-removing product after enrichment at the top of the light-removing tower ⑤. The light component discharge pipeline 2 of the light-removing subunit is connected to the feed port 6 of the light component enrichment tower ⑤, and the feed port 6 is arranged in the middle and upper part of the light component enrichment tower ⑤ (the middle and upper part of the light component enrichment tower ⑤ refers to the area of ​​10%-40% from top to bottom of the light component enrichment tower), and the top discharge pipeline of the light component enrichment tower ⑤ is installed with a light component enrichment tower top heat exchanger ⑥, and the top discharge of the light component enrichment tower ⑤ located after the light component enrichment tower top heat exchanger ⑥ The pipeline branches into three routes, one of which is a tower top reflux pipe 8 connected to the light component enrichment tower ⑤, one is an acetone pipeline 9 connected to the catalytic hydrogenation device ⑧, and the other is a light component enrichment tower top extraction pipe 7. In this way, the light component enrichment tower ⑤ contains a small amount of enriched methanol and non-condensable gas propylene in addition to acetone. By adopting the above-mentioned preferred scheme, the top discharge of the light component enrichment tower ⑤ can be partially discharged through the light component enrichment tower top extraction pipe 7, so as to avoid accumulation in the system and ensure the stability of the product during the continuous operation of the system.

[0048] In some embodiments of the present invention, the light component enrichment tower ⑤ is connected to the bottom lateral feed port 10 of the catalytic hydrogenation device ⑧ through an acetone pipeline 9, and the hydrogen feed pipeline 13 is connected to the bottom of the catalytic hydrogenation device ⑧, wherein a compressor ⑦ is installed on the acetone pipeline 9; in this way, the liquid phase feed (acetone-containing material) position of the catalytic hydrogenation device ⑧ is the bottom side, and the hydrogen feed position is the bottom; research has found that compared with the upper feed, when the liquid phase feed position of the catalytic hydrogenation device is the bottom side and the hydrogen feed position is the bottom, there is a better acetone hydrogenation effect, for example, in the present invention, the acetone content in the hydrogenated product can be made ≤100ppm.

[0049] In some embodiments of the present invention, the liquid phase outlet 18 of the gas-liquid separator ⑩ is connected to the isopropanol raw material feed pipeline 1 of the delight unit.

[0050] In some embodiments of the present invention, the gas phase outlet 12 of the gas-liquid separator ⑩ is preferably connected to the hydrogen feed pipeline 13 of the catalytic hydrogenation device ⑧.

[0051] In some embodiments of the present invention, the bottom outlet of the light component enrichment tower ⑤ is preferably connected to the isopropanol raw material feed pipeline 1 through the light component enrichment tower bottom extraction pipeline 17.

[0052] In some embodiments of the present invention, the waste liquid recovery unit further includes a heavy component recovery subunit, the feed inlet of the heavy component recovery subunit is connected to the heavy component discharge pipeline 27 of the de-weighting subunit, and the top of the heavy component recovery subunit is connected to the de-weighting subunit.

[0053] In some embodiments of the present invention, the light removal unit comprises a light removal tower ①, and the light removal tower ① is provided with an isopropanol raw material feed pipeline 1 for separating light components in the isopropanol raw material;

[0054] The dehydration subunit includes a dehydration adsorption device Dehydration adsorption device The middle part is filled with a water absorbent and connected to the light removal tower ①, and the water in the isopropanol after light removal is removed by the water absorbent;

[0055] The deweighting unit includes a connected dehydration adsorption device Deweighting tower Deweighting tower Used to remove weight from dehydrated isopropanol;

[0056] The deionization subunit includes a connected deweighting tower Ion exchange adsorption device Ion exchange adsorption device Used to adsorb metal cations and anions in isopropanol after de-weighting;

[0057] The demicronizing unit includes a connected ion exchange adsorption device Membrane separation device Membrane separation device Used to remove particles from deionized isopropanol.

[0058] Due to the long time of distillation heating, the de-weighting tower There is a trace amount of acetone in the top product of the tower, which affects the quality of the product. Therefore, this stream of material is returned to the light removal tower ①. In some embodiments of the present invention, the heavy removal tower The top of the tower is connected to the light removal tower ① through the heavy removal tower top extraction pipeline 26, preferably connected to the middle and upper part of the light removal tower ①, and the feed is fed from the middle and upper part of the light removal tower ① to further purify isopropanol. It can be understood that the heavy removal tower top extraction pipeline 26 is equipped with a heavy removal tower top heat exchanger Heat exchanger at the top of the deweighting tower After that, the de-weighting tower top extraction pipeline 26 is provided with a de-weighting tower The deweighting tower is equipped with a reflux pipe 28 for the kettle of the deweighting tower.

[0059] The purpose of the light-removal tower ① is to remove light components from the isopropanol raw material. In order to ensure that there are as few light components as possible in the bottom product of the tower, the feeding position of the isopropanol raw material needs to be close to the upper part of the light-removal tower ①. However, the higher the feeding position, the lower the recovery rate of the bottom product of the light-removal tower ① will be, which will result in a significant reduction in the recovery rate of ultra-clean high-purity isopropanol in the overall system. In some embodiments of the present invention, the isopropanol raw material feed pipeline 1 is arranged in the middle and upper part of the light-removal tower ①. In the present invention, the middle and upper part of the light-removal tower refers to the area of ​​10%-40% from top to bottom of the light-removal tower.

[0060] In some embodiments of the present invention, the dehydration adsorption device The top and deweighting tower The middle and lower parts are connected, and the weight removal tower The side line extraction position is the middle and upper part of the deweighting tower (the middle and upper part of the deweighting tower in the present invention refers to the 10%-40% area from top to bottom of the deweighting tower). The purpose of the deweighting tower is to remove the bottom product after being treated by the lightness removing tower. For this reason, the feeding position of the deweighting tower is the middle and lower part of the deweighting tower, which can ensure that there are no heavy components in the top product and the test line product of the deweighting tower.

[0061] The purpose of the heavy component enrichment tower is to further concentrate the de-heavy product after being enriched at the top of the de-heavy tower. In some embodiments of the present invention, the heavy component recovery subunit includes a heavy component enrichment tower. Deweighting tower The heavy component discharge pipeline 27 arranged at the bottom of the tower is connected to the heavy component enrichment tower The middle and lower part of the heavy component enrichment tower (in the present invention, the middle and lower part of the heavy component enrichment tower refers to the area of ​​10%-40% from bottom to top of the heavy component enrichment tower) is connected, and the heavy component enrichment tower The tower top extraction pipeline 30 and the deweighting tower Connected, among which, the heavy component enrichment tower The top extraction pipeline 30 of the tower is equipped with a heavy component enrichment tower top heat exchanger Located in the heat exchanger The top extraction pipeline 30 of the tower branches out to form a heavy component enrichment tower The top reflux pipe 29 of the tower, the heavy component enrichment tower The bottom is equipped with a heavy component enrichment tower kettle produced liquid pipeline 32 and a heavy component enrichment tower kettle reflux liquid pipeline 31, and the tower kettle reflux liquid pipeline 31 is equipped with a heavy component enrichment tower kettle heat exchanger

[0062] To reduce energy consumption, in some embodiments of the present invention, the purification system includes a heat exchange unit, which includes a heat exchanger at the top of the light removal tower and a heat exchanger at the bottom of the heavy removal tower. in,

[0063] The light component removal tower top heat exchanger ② is used to realize heat exchange between the tower top material of the light component removal tower ① and the tower bottom material of the light component enrichment tower ⑤; specifically, for example, the tower bottom reflux pipeline 16 of the light component enrichment tower ⑤ is connected to the tube side of the light component removal tower top heat exchanger ②, and the light component discharge pipeline 2 is connected to the shell side of the light component removal tower top heat exchanger ② to realize heat exchange between the two;

[0064] Degravity tower kettle heat exchanger Used to realize the discharge of the bottom of the light removal tower① and the heavy removal tower Heat exchange of feed materials, specifically, for example, connecting the bottom of the light removal tower ① and the dehydration adsorption device The bottom of the light removal tower kettle discharge pipeline 19 is connected to the heavy removal tower kettle heat exchanger The shell side is connected, and the de-weighting tower kettle reflux pipe 28 is connected to the de-weighting tower kettle heat exchanger The pipes are connected.

[0065] It can be understood that, according to actual needs, the present invention can install a heat exchanger ③ of the tower kettle of the light-removing tower on the tower kettle reflux pipe 20, install a hydrogen compressor ⑨ on the hydrogen feed pipeline 13, install a liquid pressure reducer I④ on the light component discharge pipeline 2, and install a liquid pressure reducer II on the tower kettle discharge pipeline 19 of the light-removing tower. Etc., the present invention will not go into details therein.

[0066] In the present invention, the light component removal tower, light component enrichment tower, heavy component removal tower and heavy component enrichment tower can be common distillation equipment, and the present invention has no special requirements for this and will not be described in detail.

[0067] Another aspect of the present invention discloses a method for purifying isopropanol, which uses the isopropanol purification system of the present invention, and comprises the following steps:

[0068] The isopropyl alcohol raw material is fed to the light removal unit through the isopropyl alcohol raw material feed pipeline 1, so that the isopropyl alcohol raw material is sequentially subjected to light removal, dehydration, heaviness removal, deionization and particle removal to obtain purified isopropyl alcohol; wherein the light removal of the isopropyl alcohol raw material includes removing light components including acetone;

[0069] The acetone in the light component is converted into isopropanol through the light component recovery subunit, and the isopropanol is then returned to the light component removal unit.

[0070] The invention is not only simple to operate, energy-saving and high in recovery rate, but also capable of producing high-quality ultra-clean high-purity isopropyl alcohol.

[0071] In some embodiments of the present invention, the light components discharged from the light component removal unit are distilled in the light component enrichment tower ⑤, and the top discharge obtained is entered into the catalytic hydrogenation device ⑧ for hydrogenation treatment, and then the gas-liquid separation is performed in the gas-liquid separator ⑩ to obtain the liquid phase which is returned to the light component removal unit.

[0072] In some embodiments of the present invention, preferably, the distillation conditions of the light component enrichment tower ⑤ include: a pressure of 50-101 kPa, an operating temperature of the tower bottom of 66.0°C to 82.5°C, and a reflux ratio of 0.2-2.

[0073] In some embodiments of the present invention, the hydrotreating catalyst is a copper-based catalyst.

[0074] In some embodiments of the present invention, the conditions for the hydroprocessing include: a space velocity of 0.2-0.8h -1 The molar ratio of hydrogen / feed to the bottom lateral feed port 10 of the catalytic hydrogenation device⑧ is 2-10, the reaction temperature is 80-120°C, and the pressure is 3-10Mpa.

[0075] In some embodiments of the present invention, the content of isopropyl alcohol in the isopropyl alcohol raw material is not less than 98 weight %; preferably, the isopropyl alcohol raw material also contains at least one of water, n-propyl alcohol, isopropyl ether, acetone, methyl ethyl ketone and isobutyl alcohol.

[0076] In some embodiments of the present invention, the light removal includes distillation in a light removal tower ①, and the distillation conditions of the light removal tower ① include: pressure 130-200 kPa, operating temperature of the tower bottom 86.5°C to 101°C, and reflux ratio 2-20.

[0077] In some embodiments of the present invention, dehydration includes dehydration in a dehydration adsorption device. Dehydration is carried out by adsorption, and the water absorbent is preferably selected from molecular sieve membranes and / or molecular sieves, and more preferably NaA type pervaporation molecular sieve membranes and / or A type molecular sieves. There are no special requirements, for example, adsorption columns or adsorption towers can be used in the present invention, and the present invention will not elaborate on this.

[0078] In some embodiments of the present invention, degravity is included in a degravity tower. Distillation, de-weighting tower The distillation conditions include: pressure of 101-150 kPa, bottom operating temperature of 82.5-92.5°C, and reflux ratio of 0.2-5.

[0079] In some embodiments of the present invention, the deionization includes in an ion exchange adsorption device Ion exchange resin is used for adsorption, and the ion exchange resin is preferably a mixed resin including hydrogen-type strong acid cation exchange resin and hydroxide-type strong basic anion exchange resin; more preferably, the mass ratio of hydrogen-type strong acid cation exchange resin to hydroxide-type strong basic anion exchange resin is 3:1-1:3. There are no special requirements, such as adsorption columns or adsorbers can be used in the present invention, and the present invention will not elaborate on this.

[0080] In some embodiments of the present invention, degranulation includes the step of: Membrane separation is carried out, preferably at least four stages of membrane separation are used; more preferably, the material of the membrane separation is at least one of PTFE, PVDF and PE.

[0081] In some embodiments of the present invention, the light components discharged from the light component removal unit are distilled in the light component enrichment tower ⑤ to obtain 95-99wt%, preferably 97-99wt% of the light components, which enter the catalytic hydrogenation unit ⑧ for hydrogenation treatment.

[0082] In some embodiments of the present invention, the deweighting tower The heavy components removed from the reactor enter the heavy component enrichment tower. The top liquid after distillation is returned to the de-weighting tower Optimize the heavy component enrichment tower The distillation conditions include: pressure of 50-101 kPa, reflux ratio of 0.2-2, and bottom operating temperature of 66.5-83.0°C.

[0083] In some embodiments of the present invention, the top material of the light-removal tower ① is heat-exchanged with the bottom material of the light-group enrichment tower ⑤ through the light-removal tower top heat exchanger ②.

[0084] In some embodiments of the present invention, the deweighting tower kettle heat exchanger The bottom discharge of the light removal tower① and the heavy removal tower The feed material is heat exchanged.

[0085] To facilitate understanding of the present invention, the present invention provides a process flow of the present invention, including: the isopropanol raw material enters the light-removing tower from the middle and upper part of the light-removing tower, and the top vapor phase of the light-removing tower is heat-exchanged in the tower top heat exchanger of the light-removing tower, and a part of it is returned to the light-removing tower as reflux liquid, and the other part enters the light component enrichment tower after being decompressed by the pressure reducer. After separation in the light component enrichment tower, a part of the tower bottom product is directly returned to the feed pipeline of the light-removing tower, and a part of it is heat-exchanged with the tower top heat exchanger of the light-removing tower and then vaporized and enters the tower bottom of the light component enrichment tower. The top product of the light component enrichment tower is partly discharged directly out of the boundary area, partly returned to the light component enrichment tower as reflux liquid, and partly entered from the bottom side of the catalytic hydrogenation device after being pressurized, and the pressurized hydrogen also enters from the bottom of the catalytic hydrogenation device. At the top of the catalytic hydrogenation unit, a hydrogenated gas-liquid mixture is obtained. After separation in the gas-liquid separator, the gas phase product (mainly hydrogen) returns to the hydrogen inlet, while the liquid phase product is also mixed with the raw materials of the light removal tower.

[0086] The produced liquid from the bottom of the light removal tower is regulated by the pressure reducing regulator, and then heat exchanged with the bottom heat exchanger of the heavy removal tower before entering the dehydration device, while the bottom reflux liquid of the light removal tower is heated by the bottom heat exchanger of the light removal tower and enters the light removal tower in the form of vapor phase. The dehydrated isopropyl alcohol product directly enters the heavy removal tower from the middle and lower part of the heavy removal tower. After separation in the heavy removal tower, part of the bottom product of the heavy removal tower is directly discharged and enters from the middle and lower part of the heavy component enrichment tower, and part of it is heat exchanged with the bottom heat exchanger of the heavy removal tower and then enters the bottom of the heavy removal tower in the form of vapor phase. The top product of the heavy removal tower enters from the middle and upper part of the light removal tower after heat exchange in the top heat exchanger of the heavy removal tower. The side product of the heavy removal tower is successively deionized by ion exchange and degranulated by membrane separation to obtain an ultra-clean high-purity isopropyl alcohol product. The bottom product of the de-heavy component tower entering the heavy component enrichment tower is separated in the heavy component enrichment tower, and the bottom product obtains an isopropanol product with a higher heavy component content, while the top product is combined with the feed of the de-heavy component tower after dehydration and enters the de-heavy component tower.

[0087] The advantages of the present invention will be described below by way of examples, but the present invention is not limited thereto.

[0088] In the present invention, the reagents and raw materials used in the present invention are all commercially available, the catalysts used in the examples and comparative examples are all the same copper-based catalysts, the purity of the products in the examples are all detected by HPLC, the water content is determined by a Karl Fischer titrator, the metal ions are determined by ICP-MS, and the number of particles is determined online by a particle counter.

[0089] Example 1

[0090] This embodiment adopts Figure 1The purification system of isopropyl alcohol shown in the figure is implemented. A batch of industrial grade isopropyl alcohol is measured to have a purity of 99.1% by weight of isopropyl alcohol, a water content of 1250ppm, and 370ppm of acetone. The middle and upper part of the light component removal tower (20% from top to bottom) is driven into the light component removal tower. The operating pressure of the light component removal tower is 160kPa, and the reflux ratio is 17. At this time, the operating temperature of the tower bottom of the light component removal tower is 94.8°C. After separation in the light component removal tower, the top vapor phase is heat-exchanged in the light component removal tower top heat exchanger, and part of it is returned to the light component removal tower as reflux liquid, and the other part enters the middle and upper part of the light component enrichment tower (30% from top to bottom) after the pressure reducer is reduced. The operating pressure of the light component enrichment tower is 60kPa, and the reflux ratio is 1. At this time, the operating temperature of the tower bottom of the light component enrichment tower is 70.1°C. After separation in the light component enrichment tower, a portion (20%) of the tower bottom product is directly returned to the isopropanol raw material feed pipeline of the light component removal tower, and a portion is vaporized and enters the tower bottom of the light component enrichment tower after heat exchange with the top heat exchanger of the light component removal tower. The non-condensable gas portion of the top product of the light component enrichment tower is directly discharged out of the boundary area, a portion (44.4%) is returned to the light component enrichment tower as reflux liquid, and another portion is pressurized and enters from the bottom side feed port of the catalytic hydrogenation unit, and the pressurized hydrogen also enters from the bottom of the catalytic hydrogenation unit. The mass ratio of the discharge out of the boundary and the entry into the catalytic hydrogenation unit is 3%:97%. Catalytic hydrogenation at an air velocity of 0.5h -1 , the feed (in terms of ketone compounds) of hydrogen / bottom lateral feed port 10 is 8 (molar ratio), the reaction temperature is 115°C, and the pressure is 6MPa. After the above catalytic hydrogenation process (the catalyst is a copper-based catalyst, the same below), the acetone content in the top product of the light component enrichment tower can be reduced from 5250ppm to 72ppm. After the hydrogenated gas-liquid mixed product is separated by a gas-liquid separator, the gas phase product returns to the hydrogen feed pipeline for reuse, and the liquid phase crude product enters the light component removal tower together with the industrial grade isopropanol.

[0091] After the dehydration adjustment, the produced liquid from the bottom of the light-removing tower is heat exchanged with the bottom heat exchanger of the dehydrating tower, and then enters the dehydration adsorption device. The dehydration device uses 5A molecular sieve. After dehydration treatment, the product enters from the middle and lower part of the dehydrating tower (20% from bottom to top). The operating pressure of the dehydrating tower is 101kPa, and the reflux ratio is 1.5. At this time, the operating temperature of the bottom of the dehydrating tower is 82.5℃. After the treatment of the dehydrating tower, part of the bottom product of the dehydrating tower (10%) is directly discharged and enters from the middle and lower part of the heavy component enrichment tower (30% from bottom to top), and part of it is heat exchanged with the bottom heat exchanger of the light-removing tower, and then enters and returns to the bottom of the dehydrating tower in the form of vapor phase. The top product of the dehydrating tower enters from the middle and upper part of the dehydrating tower (30% from top to bottom) after heat exchange in the top heat exchanger of the dehydrating tower. The bottom product of the de-heavy component tower entering the heavy component enrichment tower has an operating pressure of 70 kPa and a reflux ratio of 1. At this time, the bottom operating temperature of the heavy component enrichment tower is 73.5 ° C. Under the separation conditions, after separation in the heavy component enrichment tower, the bottom obtains an isopropanol product with a high heavy component content, and the top product is combined with the feed of the de-heavy component tower after dehydration and enters the de-heavy component tower.

[0092] The side product of the de-weighting tower is successively subjected to ion exchange deionization and membrane separation de-particle removal to obtain ultra-clean high-purity isopropyl alcohol product. The deionization uses mixed bed resin (including hydrogen-type strong acid cation exchange resin and hydroxide-type strong base anion exchange resin, and the mass ratio is 1:1) and the membrane separation material uses PTFE. After four-stage filtration at 200nm, 100nm, 50nm and 30nm, ultra-clean high-purity isopropyl alcohol is obtained. The product purity is 99.998%, the water content is 32ppm, the recovery rate is 92.9%, the single metal ion in the product is ≤10ppt, and the particles (≥50nm) are ≤10 / ml.

[0093] Example 2

[0094] This embodiment adopts Figure 1The purification system of isopropyl alcohol shown in the figure is implemented. A batch of industrial grade isopropyl alcohol is measured to have a purity of 98.5% by weight of isopropyl alcohol, a water content of 6200ppm, and 1800ppm of acetone. The middle and upper part of the light component removal tower (20% from top to bottom) is driven in. The operating pressure of the light component removal tower is 200kPa, and the reflux ratio is 8. At this time, the operating temperature of the tower bottom of the light component removal tower is 100.7°C. After separation in the light component removal tower, the top vapor phase is heat-exchanged in the top heat exchanger of the light component removal tower, and part of it is returned to the light component removal tower as reflux liquid, and the other part enters the middle and upper part of the light component enrichment tower (30% from top to bottom) after the pressure reducer is reduced. The operating pressure of the light component enrichment tower is 90kPa, and the reflux ratio is 2. At this time, the operating temperature of the tower bottom of the light component enrichment tower is 79.5°C. After separation in the light component enrichment tower, a portion (15%) of the tower bottom product is directly returned to the isopropanol raw material feed pipeline of the light component removal tower, and a portion is vaporized and enters the tower bottom of the light component enrichment tower after heat exchange with the top heat exchanger of the light component removal tower. Part of the top product of the light component enrichment tower is directly discharged out of the boundary area, part (60%) is returned to the light component enrichment tower as reflux liquid, and another part enters from the bottom side feed port of the catalytic hydrogenation unit after pressurization, and the pressurized hydrogen also enters from the bottom of the catalytic hydrogenation unit. The mass ratio of the discharge out of the boundary and the entry into the catalytic hydrogenation unit is 4%:96%. Catalytic hydrogenation at an air velocity of 0.7h -1 , the feed (in terms of ketone compounds) of hydrogen / bottom lateral feed port 10 is 8 (molar ratio), the reaction temperature is 100°C, and the pressure is 8MPa. After the above catalytic hydrogenation process, the acetone content in the top product of the light component enrichment tower can be reduced from 27000ppm to 120ppm. After the hydrogenated gas-liquid mixed product is separated by a gas-liquid separator, the gas phase product returns to the hydrogen feed pipeline for reuse, and the liquid phase crude product enters the light component removal tower together with the industrial grade isopropanol.

[0095] After the dehydration adjustment, the produced liquid from the bottom of the light-removing tower is heat exchanged with the bottom heat exchanger of the dehydrating tower, and then enters the dehydration adsorption device. The dehydration device uses 4A molecular sieve. After dehydration treatment, the product enters from the middle and lower part of the dehydrating tower (20% from bottom to top). The operating pressure of the dehydrating tower is 150kPa, and the reflux ratio is 2. At this time, the operating temperature of the bottom of the dehydrating tower is 92.8℃. After the treatment of the dehydrating tower, part of the bottom product of the dehydrating tower (10%) is directly discharged and enters from the middle and lower part of the heavy component enrichment tower (20% from bottom to top), and part of it is heat exchanged with the bottom heat exchanger of the dehydrating tower, and then enters and returns to the bottom of the dehydrating tower in the form of vapor phase. The top product of the dehydrating tower enters from the middle and upper part of the light-removing tower (30% from top to bottom) after heat exchange in the top heat exchanger of the dehydrating tower. The bottom product of the de-heavy component tower entering the heavy component enrichment tower has an operating pressure of 80 kPa and a reflux ratio of 2. At this time, the bottom operating temperature of the heavy component enrichment tower is 76.7 ° C. Under the separation conditions, after separation in the heavy component enrichment tower, the bottom obtains an isopropanol product with a high heavy component content, and the top product is combined with the feed of the de-heavy component tower after dehydration and enters the de-heavy component tower.

[0096] The product of the de-weighting tower is successively deionized by ion exchange and de-particled by membrane separation to obtain ultra-clean high-purity isopropyl alcohol. The deionization uses mixed bed resin (including hydrogen-type strong acid cation exchange resin and hydroxide-type strong base anion exchange resin, and the mass ratio is 1:1.2) and the membrane separation material uses PTFE. After four-stage filtration at 200nm, 100nm, 50nm and 30nm, ultra-clean high-purity isopropyl alcohol is obtained. The product purity is 99.996%, the water content is 47ppm, the recovery rate is 91.2%, the single metal ion in the product is ≤10ppt, and the particles (≥50nm) are ≤10 / ml.

[0097] Example 3

[0098] The difference from Example 1 is that the operating pressure of the light component removal tower is 130 kPa, the reflux ratio is 5, and the operating temperature of the bottom of the light component removal tower is 87°C; the operating pressure of the light component enrichment tower is 50 kPa, the reflux ratio is 0.3, and the operating temperature of the bottom of the light component enrichment tower is 68°C. -1 , the hydrogen / feed (in terms of ketone compounds) of the bottom lateral feed port 10 is 3 (molar ratio), the reaction temperature is 80° C., and the pressure is 3 MPa. After the above catalytic hydrogenation process, the acetone content in the top product of the light component enrichment tower can be reduced from 6300 ppm to below 198 ppm.

[0099] The operating pressure of the de-weighting tower is 125 kPa, the reflux ratio is 5, and the operating temperature of the bottom of the de-weighting tower is 86.2° C. The operating pressure of the heavy component enrichment tower is 55 kPa, the reflux ratio is 0.5, and the operating temperature of the bottom of the heavy component enrichment tower is 68° C.

[0100] Ultra-clean high-purity isopropanol is obtained, wherein the product purity is 99.996%, the water content is 38ppm, the recovery rate is 87.4%, the single metal ion in the product is ≤10ppt, and the particles (≥50nm) are ≤10 / ml.

[0101] Example 4

[0102] Different from Example 1, the operating pressure of the lightness removal tower is 160 kPa, and the reflux ratio is 0.5. At this time, the operating temperature of the bottom of the lightness removal tower is 94.8°C.

[0103] Ultra-clean high-purity isopropanol is obtained, wherein the product purity is 99.994%, the water content is 50ppm, the recovery rate is 89.5%, the single metal ion in the product is ≤10ppt, and the particles (≥50nm) are ≤10 / ml.

[0104] Example 5

[0105] Different from Example 1, the operating pressure of the deweighting tower is 70 kPa, the reflux ratio is 1.5, and the operating temperature of the bottom of the deweighting tower is 73.5°C.

[0106] Ultra-clean high-purity isopropanol is obtained, wherein the product purity is 99.994%, the water content is 42ppm, the recovery rate is 91.4%, the single metal ion in the product is ≤10ppt, and the particles (≥50nm) are ≤10 / ml.

[0107] Example 6

[0108] The difference from Example 1 is that the deweighting tower The top of the tower is not provided with a deheaving tower top extraction pipeline 26 connected to the light-removing tower ①, that is, the top product of the deheaving tower is not returned to the light-removing tower.

[0109] Ultra-clean high-purity isopropanol is obtained, wherein the product purity is 99.997%, the water content is 34ppm, the recovery rate is 88.3%, the single metal ion in the product is ≤10ppt, and the particles (≥50nm) are ≤10 / ml.

[0110] Example 7

[0111] Different from Example 1, no light component enrichment tower is provided, and the light component discharge pipeline 2 is directly connected to the catalytic hydrogenation device.

[0112] Ultra-clean high-purity isopropanol is obtained, wherein the product purity is 99.988%, the water content is 68ppm, the recovery rate is 93.1%, the single metal ion in the product is ≤10ppt, and the particles (≥50nm) are ≤10 / ml.

[0113] Example 8

[0114] Different from Example 1, no heavy component enrichment tower is provided, and the bottom discharge of the deweighting tower is directly discharged from the system.

[0115] Ultra-clean high-purity isopropanol is obtained, wherein the product purity is 99.998%, the water content is 30ppm, the recovery rate is 87.1%, the single metal ion in the product is ≤10ppt, and the particles (≥50nm) are ≤10 / ml.

[0116] Example 9

[0117] The difference from Example 1 is that the isopropanol raw material feed pipeline 1 is arranged at a height position of 60% from top to bottom of the lightness removal tower.

[0118] Ultra-clean high-purity isopropanol is obtained, wherein the product purity is 99.993%, the water content is 45ppm, the recovery rate is 92.2%, the single metal ion in the product is ≤10ppt, and the particles (≥50nm) are ≤10 / ml.

[0119] Example 10

[0120] The difference from Example 1 is that the extraction pipeline 26 at the top of the heavy removal tower is arranged at 70% of the height from the top to the bottom of the light removal tower.

[0121] Ultra-clean high-purity isopropanol is obtained, wherein the product purity is 99.996%, the water content is 34ppm, the recovery rate is 92.5%, the single metal ion in the product is ≤10ppt, and the particles (≥50nm) are ≤10 / ml.

[0122] Embodiment 11

[0123] The difference from Example 1 is that the heavy component discharge pipeline 27 of the de-heaving tower is connected to the 70% height position of the heavy component enrichment tower from bottom to top.

[0124] Ultra-clean high-purity isopropanol is obtained, wherein the product purity is 99.996%, the water content is 36ppm, the recovery rate is 92.6%, the single metal ion in the product is ≤10ppt, and the particles (≥50nm) are ≤10 / ml.

[0125] Example 12

[0126] The difference from Example 1 is that the dehydration adsorption device is connected to the 50% position from bottom to top of the deweighting tower.

[0127] Ultra-clean high-purity isopropanol is obtained, wherein the product purity is 99.991%, the water content is 45ppm, the recovery rate is 92.4%, the single metal ion in the product is ≤10ppt, and the particles (≥50nm) are ≤10 / ml.

[0128] Comparative Example 1

[0129] The difference from Example 1 is that no catalytic hydrogenation device is provided.

[0130] Ultra-clean high-purity isopropanol is obtained, wherein the product purity is 99.969%, the water content is 240ppm, the recovery rate is 92.8%, the single metal ion in the product is ≤10ppt, and the particles (≥50nm) are ≤10 / ml.

[0131] Comparative Example 2

[0132] The difference from Example 1 is that the positions of the deweighting tower and the dehydration adsorption device are swapped, that is, the isopropyl alcohol raw material is sequentially subjected to light removal, heavy removal, dehydration, deionization and demicronization to obtain purified isopropyl alcohol.

[0133] Ultra-clean high-purity isopropanol is obtained, wherein the product purity is 99.994%, the water content is 27ppm, the recovery rate is 92.5%, the single metal ion in the product is ≤1000ppt, and the particles (≥50nm) are ≤500 / ml.

[0134] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various specific technical features in any appropriate manner. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. However, these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A system for purifying isopropanol, characterized in that: The purification system comprises: The isopropyl alcohol purification unit comprises a light removal unit, a water removal unit, a heavy removal unit, an ion removal unit and a micron removal unit which are sequentially connected in series along the material flow direction, so as to sequentially remove light, water, heavy, ion and micron from the isopropyl alcohol raw material to obtain purified isopropyl alcohol; Wherein, the isopropanol raw material light removal includes removing light components containing acetone; The waste liquid recovery unit comprises a light component recovery subunit, which is connected to the light component removal unit so that the light component can enter the light component recovery unit, convert the acetone in the light component into isopropanol and then return to the light component removal unit.

2. The purification system according to claim 1, characterized in that The light component recovery subunit comprises a light component enrichment tower (⑤), the catalytic hydrogenation device (⑧) and a gas-liquid separator (⑩) which are sequentially connected in series, wherein: The feed inlet (6) of the light component enrichment tower (⑤) is connected to the light component discharge pipeline (2) of the light component removal unit; The liquid phase outlet (18) of the gas-liquid separator (⑩) is connected to the isopropanol raw material feed pipeline (1) of the delightening unit; Preferably, the bottom outlet of the light component enrichment tower (⑤) is connected to the isopropanol raw material feed pipeline (1); and / or Preferably, the gas phase outlet (12) of the gas-liquid separator (⑩) is connected to the hydrogen feed pipeline (13) of the catalytic hydrogenation device (⑧).

3. The purification system according to claim 1 or 2, characterized in that: The waste liquid recovery unit also includes a heavy component recovery subunit, the feed inlet of the heavy component recovery subunit is connected to the heavy component discharge pipeline (27) of the de-weighting subunit, and the tower top of the heavy component recovery subunit is connected to the de-weighting subunit.

4. The purification system according to any one of claims 1 to 3, characterized in that: The light removal unit comprises a light removal tower (①), wherein the light removal tower (①) is provided with an isopropanol raw material feed pipeline (1) for separating light components in the isopropanol raw material; The dehydration subunit includes a dehydration adsorption device The dehydration adsorption device A water absorbing agent is loaded in the middle and is connected to the light removal tower (①), and the water in the isopropanol after light removal is removed by the water absorbing agent; The deweighting unit includes a dehydration adsorption device connected to the Deweighting tower The deweighting tower Used to remove weight from dehydrated isopropanol; The deionizing subunit includes a deweighting tower connected to the Ion exchange adsorption device The ion exchange adsorption device Used to adsorb metal cations and anions in isopropanol after de-weighting; The demicronizing unit includes an ion exchange adsorption device connected to the Membrane separation device The membrane separation device Used to remove particles from deionized isopropanol.

5. The purification system according to claim 4, characterized in that The deweighting tower The top of the tower is connected to the light-removal tower (①) through a heavy-removal tower top extraction pipeline (26), preferably connected to the feed inlet at the middle and upper part of the light-removal tower (①); and / or The isopropanol raw material feed pipeline (1) is arranged in the middle and upper part of the light removal tower (①); and / or The light component discharge pipeline (2) is connected to the feed inlet at the middle and upper part of the light component enrichment tower (⑤); and / or The top outlet of the light component enrichment tower (⑤) is connected to the bottom lateral feed port (10) of the catalytic hydrogenation device (⑧), and the hydrogen feed pipeline (13) is connected to the bottom of the catalytic hydrogenation device (⑧); and / or The dehydration adsorption device The discharge port and the deweighting tower The feed inlet at the middle and lower parts is connected; and / or The heavy component recovery subunit includes a heavy component enrichment tower Deweighting tower The heavy component discharge pipeline (27) and the heavy component enrichment tower The feed inlet at the middle and lower part of the heavy component enrichment tower is connected to The tower top extraction pipeline (30) and the deweighting tower The feed inlet is connected.

6. The purification system according to claim 4 or 5, characterized in that: The purification system comprises a heat exchange unit, wherein the heat exchange unit comprises a light removal tower (①), a tower top heat exchanger (②) and a heavy removal tower Tower Bottom Heat Exchanger in, The top heat exchanger (②) of the light component removal tower (①) is used to realize heat exchange between the top material of the light component removal tower (①) and the bottom material of the light component enrichment tower (⑤); The deweighting tower Tower Bottom Heat Exchanger It is used to realize the discharge of the bottom of the light removal tower (①) and the heavy removal tower Heat exchange of tower bottom materials.

7. A method for purifying isopropanol, characterized in that: The purification method adopts the isopropanol purification system according to any one of claims 1 to 6, comprising: Feeding an isopropyl alcohol raw material into a light component removal unit, so that the isopropyl alcohol raw material is sequentially subjected to light component removal, dehydration, heavy component removal, deionization and particle removal to obtain purified isopropyl alcohol; wherein the light component removal of the isopropyl alcohol raw material includes removing light components including acetone; The acetone in the light component is converted into isopropanol through the light component recovery subunit, and the isopropanol is returned to the light removal unit.

8. The purification method according to claim 7, wherein: The light components discharged from the de-lightening unit are distilled in a light component enrichment tower (⑤), and the obtained top discharge is sent to a catalytic hydrogenation device (⑧) for hydrogenation treatment, and then separated from the gas by a gas-liquid separator (⑩), and the obtained liquid phase is returned to the de-lightening unit; Preferably, The distillation conditions of the light component enrichment tower (⑤) include: a pressure of 50-101 kPa, an operating temperature of the tower bottom of 66.0° C. to 82.5° C., and a reflux ratio of 0.2-2; and / or The hydrotreating catalyst is a copper-based catalyst; and / or Hydrogenation treatment conditions include: space velocity 0.2-0.8h -1 The molar ratio of hydrogen / feed from the bottom side feed port (10) is 2-10, the temperature is 80-120°C, and the pressure is 3-10Mpa.

9. The purification method according to claim 7 or 8, wherein: The content of isopropanol in the isopropanol raw material is not less than 98% by weight; preferably, the isopropanol raw material further contains at least one of water, n-propanol, isopropyl ether, acetone, methyl ethyl ketone and isobutyl alcohol; and / or The light removal comprises distillation in a light removal tower (①), and the distillation conditions of the light removal tower (①) include: a pressure of 130-200 kPa, an operating temperature of the tower bottom of 86.5° C. to 101° C., and a reflux ratio of 2-20; and / or The dehydration includes a dehydration adsorption device Adsorption dehydration is performed, preferably the water absorbent is selected from molecular sieve membranes and / or molecular sieves, more preferably NaA type pervaporation molecular sieve membranes and / or A type molecular sieves; and / or The deweighting includes a deweighting tower The deweighting tower is distilled The distillation conditions include: pressure of 101-150 kPa, operating temperature of the tower bottom of 82.5-92.5° C., reflux ratio of 0.2-5; and / or The deionizer is included in the ion exchange adsorption device The ion exchange resin is used for adsorption, and the ion exchange resin is preferably a mixed resin comprising a hydrogen-type strongly acidic cation exchange resin and a hydroxide-type strongly basic anion exchange resin; more preferably, the mass ratio of the hydrogen-type strongly acidic cation exchange resin to the hydroxide-type strongly basic anion exchange resin is 3:1-1:3; and / or The demicronization includes a membrane separation device Membrane separation is carried out, preferably at least four stages of membrane separation are used; more preferably, the material of the membrane separation is at least one of PTFE, PVDF and PE.

10. The purification method according to any one of claims 7 to 9, wherein: The light components discharged from the light component removal unit are distilled in a light component enrichment tower (⑤) to obtain 95-99wt%, preferably 97-99wt%, of light components which enter a catalytic hydrogenation unit (⑧) for hydrogenation treatment; and / or Deweighting tower The heavy components removed from the reactor enter the heavy component enrichment tower. The overhead liquid after distillation is returned to the de-weighting tower Optimize the heavy component enrichment tower The distillation conditions include: pressure of 50-101 kPa, reflux ratio of 0.2-2, and bottom operating temperature of 66.5-83.0°C; and / or The overhead material of the light-removal tower (①) is heat exchanged with the bottom material of the light-group enrichment tower (⑤) through the light-removal tower overhead heat exchanger (②); and / or Through the deweighting tower kettle heat exchanger The bottom discharge of the light removal tower (①) and the heavy removal tower The feed material is heat exchanged.

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