Isopropanol purification system and method

Abstract

The present application relates to the field of wet electronic chemical preparation required in semiconductor manufacturing process, and discloses a purification system of isopropyl alcohol, comprising an isopropyl alcohol purification unit and a waste liquid recovery unit, wherein the isopropyl alcohol purification unit comprises a light component removal subunit, a dehydration subunit, a heavy component removal subunit, an ion removal subunit and a fine particle removal subunit connected in series along the material flow direction, for sequentially removing light components, water, heavy components, ions and fine particles from isopropyl alcohol raw materials to obtain purified isopropyl alcohol; wherein the light component removal of the isopropyl alcohol raw materials comprises removing light components containing acetone; the waste liquid recovery unit comprises a light component recovery subunit, which is connected with the light component removal subunit. The method has good stability, the product recovery rate is higher than that of the traditional process, the product has high purity, low water content and low metal ion residue, and can be used in the integrated circuit industry.

Description

TECHNICAL FIELD

[0001] The application relates to a high-end wet electronic chemical preparation technology for an integrated circuit (IC), in particular to a purification system and method of isopropanol. BACKGROUND

[0002] The super-clean high-purity reagent is a special chemical for manufacturing processes of large-scale integrated circuits (ICs) and high-end semiconductor devices, and is mainly used in cleaning, photoetching and etching processes of silicon single wafers. The purity and cleanliness of the super-clean high-purity reagent have important influences on the yield rate, electrical performance and reliability of the integrated circuits.

[0003] The super-clean high-purity isopropanol is an important wet electronic chemical and an organic wet electronic chemical with the largest consumption. The super-clean high-purity isopropanol is often used as a cleaning agent and a drying agent for the last cleaning of silicon wafers. Therefore, the product quality of the super-clean high-purity isopropanol has a crucial influence on the yield rate of the integrated circuits. As the super-clean high-purity isopropanol, the purity, organic impurities, water content, cation and anion residues and particulate matter residues of the product have extremely strict requirements. The higher the product quality of the integrated circuits is, the more strict the requirements on the above indexes are.

[0004] With the development of the domestic integrated circuit industry, the preparation method of the super-clean high-purity isopropanol has attracted certain attention, and some related reports are available. For example, CN 111517917A reports a production system of electronic-grade isopropanol, which comprises a raw material conveying unit, a molecular sieve adsorption unit, an evaporation tank, a first rectification unit, a second rectification unit and a filtering unit. CN 114870420A discloses a production method and device of high-purity electronic-grade isopropanol, which comprises a dehydration processor, a microfilter, a cation and anion remover, rectification and nanofiltration steps. In the prior art, the removal methods of the organic impurities in the product are similar, and the organic impurities are removed through multiple-stage rectification. However, the method has poor effect on the removal of some organic impurities, and simultaneously causes low recovery rate of the super-clean high-purity isopropanol, which greatly influences the stable production of the product and the economic production efficiency of the enterprise.

[0005] Based on the analysis of the reported preparation processes of the super-clean high-purity isopropanol, it is urgent to develop a preparation system of the super-clean high-purity isopropanol with good removal effect of the organic impurities, stable product quality and high recovery rate. SUMMARY

[0006] The application aims to overcome the problems of low recovery rate, high energy consumption and poor product grade in the prior art, and provides a purification system and method of isopropanol, which has the advantages of simple operation, energy saving, high recovery rate and the ability to produce high-quality super-clean high-purity isopropanol.

[0007] In order to achieve the above object, the present application provides, in one aspect, a purification system of isopropanol, comprising:

[0008] The isopropanol purification unit comprises, in sequence along the material flow direction, a light component removal subunit, a dehydration subunit, a heavy component removal subunit, an ion removal subunit and a fine particle removal subunit, for sequentially removing light components, water, heavy components, ions and fine particles from isopropanol raw materials to obtain purified isopropanol;

[0009] The light component removal from the isopropanol raw materials comprises removing light components containing acetone;

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

[0011] The present application provides, in a second aspect, a purification method of isopropanol, characterized in that the purification method uses the purification system of isopropanol according to the present application, comprising:

[0012] The isopropanol raw materials are fed into the light component removal subunit, so that the isopropanol raw materials sequentially pass through the light component removal, dehydration, heavy component removal, ion removal and fine particle removal to obtain purified isopropanol; the light component removal from the isopropanol raw materials comprises removing light components containing acetone;

[0013] The acetone in the light components is converted into isopropanol, and the isopropanol is returned to the light component removal subunit.

[0014] By the above technical solution, the purification system of isopropanol provided by the present application can obtain high-grade ultra-clean high-purity isopropanol products, has the advantages of high preparation recovery rate and efficiency, stable products, simple operation, and can realize continuous production. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a schematic diagram of the purification system of isopropanol of one embodiment.

[0016] REFERENCE SIGNS

[0017] ① light component removal column ② light component removal column overhead heat exchanger

[0018] ③ light component removal column bottom heat exchanger ④ liquid pressure reducer I

[0019] ⑤ light component enrichment column ⑥ light component enrichment column overhead heat exchanger

[0020] ⑦ compressor ⑧ catalytic hydrogenation device

[0021] ⑨ hydrogen compressor ⑩ gas-liquid separator

[0022] Liquid pressure reducer II De-enriching column reboiler

[0023] Dehydration adsorption device De-enriching column

[0024] De-enriching column overhead heat exchanger Heavy component enriching column

[0025] Heavy component enriching column overhead heat exchanger Heavy component enriching column reboiler

[0026] Ion exchange adsorption device Membrane separation device

[0027] 1 Isopropanol feed line 2 Light component discharge line

[0028] 6 Light component enriching column feed port 7 Light component enriching column overhead take-off line

[0029] 8 Light component enriching column overhead reflux line 9 Acetone line

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

[0031] 13 Hydrogen feed line 16 Light component enriching column reboiler line 17 Light component enriching column reboiler take-off line 18 Gas-liquid separator liquid phase outlet

[0032] 19 De-enriching column reboiler discharge line 20 De-enriching column reboiler reflux line

[0033] 25 De-enriching column overhead reflux line 26 De-enriching column overhead take-off line

[0034] 27 De-enriching column heavy component discharge line 28 De-enriching column reboiler reflux line

[0035] 29 Heavy component enriching column overhead reflux line 30 Heavy component enriching column overhead take-off line

[0036] 31 Heavy component enriching column reboiler reflux line 32 Heavy component enriching column reboiler take-off line

[0037] 35 Ultra-clean high-purity isopropanol product DETAILED DESCRIPTION

[0038] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative and explanatory and are not intended to limit the present application.

[0039] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as implicitly split by the language of the specification. The endpoints of the ranges and any values are to be interpreted as approximately between the stated values where explicit middle points are not stated. The various range endpoints are not to be construed as being singular.

[0040] In the present application, unless otherwise specified, the orientation words such as "upper", "lower", "left", "right" generally refer to the upper, lower, left and right shown in the drawings; "inner", "outer" refer to the inner, outer relative to the contour of each component itself.

[0041] One aspect of the present application discloses a purification system of isopropyl alcohol, as shown in Figure 1 The purification system comprises:

[0042] The isopropyl alcohol purification unit comprises a light component removal subunit, a dehydration subunit, a heavy component removal subunit, an ion removal subunit and a fine particle removal subunit connected in series along the material flow direction, for sequentially removing light components, water, heavy components, ions and fine particles from isopropyl alcohol raw materials to obtain purified isopropyl alcohol;

[0043] The isopropyl alcohol raw material light component removal includes removing light components containing acetone;

[0044] The waste liquid recovery unit comprises a light component recovery subunit connected with the light component removal subunit, so that the light components can enter the light component recovery subunit, and the acetone in the light components is converted into isopropyl alcohol and returned to the light component removal subunit.

[0045] The purification system of isopropyl alcohol of the present application can effectively prepare high-grade ultra-clean high-purity isopropyl alcohol products, has the advantages of high preparation recovery rate and efficiency, stable products, simple operation, and can realize continuous production.

[0046] In some embodiments of the present application, the light component recovery subunit comprises a light component enrichment tower 5, a catalytic hydrogenation device 7 and a gas-liquid separator 9 connected in series, wherein,

[0047] The light component enrichment tower 5 is used to remove and further concentrate the light component of the light component enriched product from the light component removal tower 5. The light component removal pipeline 2 of the light component removal subunit is connected to the feed inlet 6 of the light component enrichment tower 5, and the feed inlet 6 is arranged at the middle upper part of the light component enrichment tower 5 (the middle 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 5). The tower top outlet pipeline of the light component enrichment tower 5 is provided with a light component enrichment tower top heat exchanger 6. The tower top outlet pipeline of the light component enrichment tower 5 after the light component enrichment tower top heat exchanger 6 is branched into three paths. One path is a tower top reflux pipeline 8 connected to the light component enrichment tower 5. One path is an acetone pipeline 9 connected to the catalytic hydrogenation device 7. The other path is a light component enrichment tower top outlet pipeline 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 the enriched acetone. By using the preferred scheme, the tower top outlet of the light component enrichment tower 5 can be partially discharged through the light component enrichment tower top outlet pipeline 7, so as to avoid accumulation in the system and ensure the stability of the product in the continuous operation of the system.

[0048] In some embodiments of the present application, the light component enrichment tower 5 is connected to the bottom side feed inlet 10 of the catalytic hydrogenation device 7 through the acetone pipeline 9, and the hydrogen feed pipeline 13 is connected to the bottom of the catalytic hydrogenation device 7. The acetone pipeline 9 is provided with a compressor 10. In this way, the liquid phase feed (containing acetone material) of the catalytic hydrogenation device 7 is located at the bottom side, and the hydrogen feed is located at the bottom. Studies have found that, compared with the upper feed, the liquid phase feed of the catalytic hydrogenation device is located at the bottom side, and the hydrogen feed is located at the bottom, which has a better acetone hydrogenation effect. For example, the content of acetone in the hydrogenated product is ≤100 ppm in the present application.

[0049] In some embodiments of the present application, the liquid phase outlet 18 of the gas-liquid separator 10 is connected to the isopropanol raw material feed pipeline 1 of the light component removal subunit.

[0050] In some embodiments of the present application, the gas phase outlet 12 of the gas-liquid separator 10 is connected to the hydrogen feed pipeline 13 of the catalytic hydrogenation device 7.

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

[0052] In some embodiments of the present application, the waste liquid recovery unit further comprises a heavy component recovery subunit. The feed inlet of the heavy component recovery subunit is connected to the heavy component outlet pipeline 27 of the heavy component removal subunit, and the tower top of the heavy component recovery subunit is connected to the heavy component removal subunit.

[0053] In some embodiments of the present application, the light component removal unit comprises a light component removal column ①, which is provided with an isopropanol raw material feeding pipeline 1 for separating light components in the isopropanol raw material;

[0054] The dehydration subunit comprises a dehydration adsorption device The dehydration adsorption device The dehydration adsorption device is filled with a water adsorbent and is connected to the light component removal column ①, and the water in the isopropanol after light component removal is removed by the water adsorbent;

[0055] The heavy component removal unit comprises a heavy component removal column connected to the dehydration adsorption device The heavy component removal column for removing heavy components from the isopropanol after dehydration;

[0056] The ion removal subunit comprises an ion exchange adsorption device connected to the heavy component removal column The ion exchange adsorption device for adsorbing metal cations and anions in the isopropanol after heavy component removal;

[0057] The fine particle removal unit comprises a membrane separation device connected to the ion exchange adsorption device The membrane separation device for removing fine particles in the isopropanol after ion removal.

[0058] Due to long-time rectification heating, there is a trace amount of acetone in the overhead product of the heavy component removal column , which affects the quality of the product, and therefore this material is returned to the light component removal column ①. In some embodiments of the present application, the overhead of the heavy component removal column is connected to the light component removal column ① through a heavy component removal column overhead tapping pipeline 26, which is preferably connected to the middle or upper part of the light component removal column ①, and is fed from the middle or upper part of the light component removal column ① to further purify the isopropanol. It can be understood that the heavy component removal column overhead tapping pipeline 26 is provided with a heavy component removal column overhead heat exchanger located after the heavy component removal column overhead heat exchanger The heavy component removal column overhead tapping pipeline 26 is provided with a heavy component removal column overhead reflux pipeline 25 after the heavy component removal column overhead heat exchanger , and the heavy component removal column is provided with a heavy component removal column bottom reflux pipeline 28.

[0059] The purpose of the light component removal column 1 is to remove the light components in the isopropyl alcohol raw material. In order to ensure that the light components are as little as possible in the column bottom product, the isopropyl alcohol raw material feeding position needs to be close to the upper part of the light component removal column 1. However, the higher the feeding position, the lower the recovery rate of the column bottom product of the light component removal column 1, which will lead to a significant decrease in the recovery rate of the overall system of the ultra-clean high-purity isopropyl alcohol. In some embodiments of the present application, the isopropyl alcohol raw material feeding pipeline 1 is arranged in the middle-upper part of the light component removal column 1. In the present application, the middle-upper part of the light component removal column refers to the area of 10%-40% from the top to the bottom of the light component removal column.

[0060] In some embodiments of the present application, the dehydration adsorption device is connected in communication with the middle-lower part of the heavy component removal column , and the side line extraction position of the heavy component removal column is the middle-upper part of the heavy component removal column (in the present application, the middle-upper part of the heavy component removal column refers to the area of 10%-40% from the top to the bottom of the heavy component removal column). The purpose of the heavy component removal column is to remove the column bottom product after the light component removal column. For this purpose, the feeding position of the heavy component removal column is the middle-lower part of the heavy component removal column, which can ensure that there is no heavy component in the column top product and the side line product of the heavy component removal column.

[0061] The purpose of the heavy component enrichment column is to further concentrate the heavy component product enriched by the heavy component removal column. In some embodiments of the present application, the heavy component recovery subunit includes a heavy component enrichment column The heavy component discharge pipeline 27 arranged at the bottom of the heavy component removal column is connected in communication with the middle-lower part of the heavy component enrichment column (in the present application, the middle-lower part of the heavy component enrichment column refers to the area of 10%-40% from the bottom to the top of the heavy component enrichment column), and the column top extraction pipeline 30 of the heavy component enrichment column is connected in communication with the heavy component removal column , wherein the column top extraction pipeline 30 of the heavy component enrichment column is provided with a heavy component enrichment column top heat exchanger , the column top extraction pipeline 30 after the heat exchanger diverges into a column top reflux pipeline 29 of the heavy component enrichment column , and the bottom of the heavy component enrichment column is provided with a heavy component enrichment column bottom extraction liquid pipeline 32 and a heavy component enrichment column bottom reflux liquid pipeline 31, and the heavy component enrichment column bottom reflux liquid pipeline 31 is provided with a heavy component enrichment column bottom heat exchanger

[0062] In order to reduce energy consumption, in some embodiments of the present application, the purification system includes a heat exchange unit, and the heat exchange unit includes a light component removal column top heat exchanger 2 and a heavy component removal column bottom heat exchanger , wherein

[0063] The overhead heat exchanger ② of the light-removing column is used to realize heat exchange between the overhead material of the light-removing column ① and the column bottom material of the light component enriching column ⑤; specifically, for example, the column bottom reflux pipeline 16 of the light component enriching column ⑤ is communicated with the tube side of the overhead heat exchanger ② of the light-removing column, and the light component discharge pipeline 2 is communicated with the shell side of the overhead heat exchanger ② of the light-removing column to realize heat exchange between the two.

[0064] The column bottom heat exchanger of the heavy-removing column The column bottom heat exchanger of the heavy-removing column is used to realize heat exchange between the column bottom discharge of the light-removing column ① and the feed material of the heavy-removing column ④; specifically, for example, the light-removing column ① is communicated with the column bottom of the heavy-removing column ④, and the light component enriching column ⑤ is communicated with the column bottom of the heavy-removing column ④. The column bottom heat exchanger of the heavy-removing column is used to realize heat exchange between the column bottom discharge of the light-removing column ① and the feed material of the heavy-removing column ④; specifically, for example, the light-removing column ① is communicated with the column bottom of the heavy-removing column ④, and the light component enriching column ⑤ is communicated with the column bottom of the heavy-removing column ④. The column bottom heat exchanger of the heavy-removing column is used to realize heat exchange between the column bottom discharge of the light-removing column ① and the feed material of the heavy-removing column ④; specifically, for example, the light-removing column ① is communicated with the column bottom of the heavy-removing column ④, and the light component enriching column ⑤ is communicated with the column bottom of the heavy-removing column ④.

[0065] It can be understood that, according to actual needs, the overhead heat exchanger ③ of the light-removing column can be installed on the column bottom reflux pipeline 20 of the light-removing column, the hydrogen compressor ⑨ can be installed on the hydrogen feed pipeline 13, the liquid pressure reducer I ④ can be installed on the light component discharge pipeline 2, and the liquid pressure reducer II ⑤ can be installed on the light-removing column column bottom discharge pipeline 19, and the like, and the present application will not be described here.

[0066] In the present application, the light-removing column, the light component enriching column, the heavy-removing column and the heavy component enriching column can be ordinary rectification equipment, and the present application has no special requirements therefor, and will not be described here.

[0067] Another aspect of the present application discloses a purification method of isopropyl alcohol, which adopts the purification system of isopropyl alcohol of the present application, and the method comprises the following steps.

[0068] The isopropyl alcohol raw material is fed into the light-removing subunit through the isopropyl alcohol raw material feed pipeline 1, so that the isopropyl alcohol raw material is purified by light-removing, dehydration, heavy-removing, ion-removing and microparticle-removing in sequence; wherein the light-removing of the isopropyl alcohol raw material comprises removing light components containing acetone;

[0069] The acetone in the light components is converted into isopropyl alcohol by the light component recovery subunit, and the isopropyl alcohol is returned to the light-removing subunit.

[0070] The present application not only has simple operation, energy saving and high recovery rate, but also can produce high-quality ultra-clean high-purity isopropyl alcohol.

[0071] In some embodiments of the present application, the overhead material obtained after the light component of the light-removing subunit discharge is rectified by the light component enriching column ⑤ is subjected to hydrogenation treatment in the catalytic hydrogenation device ⑧, and then the liquid phase obtained after gas-liquid separation in the gas-liquid separator ⑩ is returned to the light-removing subunit.

[0072] ​​​In some embodiments of the present application, the rectification conditions of the light component enrichment tower (5) preferably include a pressure of 50-101 kPa, a tower bottom operating temperature of 66.0-82.5°C, and a reflux ratio of 0.2-2.

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

[0074] In some embodiments of the present application, the hydrotreating conditions include a space velocity of 0.2-0.8 h -1 , a hydrogen / catalyst molar ratio of 2-10, a reaction temperature of 80-120°C, and a pressure of 3-10 MPa.

[0075] In some embodiments of the present application, the isopropyl alcohol raw material contains not less than 98% by weight of isopropyl alcohol; and preferably, the isopropyl alcohol raw material further contains at least one of water, n-propanol, isopropyl ether, acetone, methyl ethyl ketone, and isobutyl alcohol.

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

[0077] In some embodiments of the present application, the water removal includes adsorption dehydration in a water removal adsorption device , and preferably, the water adsorbent is selected from a molecular sieve membrane and / or a molecular sieve, and more preferably, is a NaA-type pervaporation molecular sieve membrane and / or an A-type molecular sieve. There is no special requirement for the water removal adsorption device , for example, an adsorption column or an adsorber can be used in the present application, and the present application will not be described hereinafter.

[0078] In some embodiments of the present application, the heavy component removal includes rectification in a heavy component removal tower , and the rectification conditions of the heavy component removal tower include a pressure of 101-150 kPa, a tower bottom operating temperature of 82.5-92.5°C, and a reflux ratio of 0.2-5.

[0079] In some embodiments of the present application, the ion removal includes ion exchange adsorption in an ion exchange adsorption device , and preferably, the ion exchange resin is a mixed resin containing a hydrogen-type strong acid cation exchange resin and a hydrogen-oxygen type strong base anion exchange resin; and more preferably, the mass ratio of the hydrogen-type strong acid cation exchange resin to the hydrogen-oxygen type strong base anion exchange resin is 3:1-1:3. There is no special requirement for the ion exchange adsorption device , for example, an adsorption column or an adsorber can be used in the present application, and the present application will not be described hereinafter.

[0080] In some embodiments of the present application, the de-micronization includes a membrane separation in a membrane separation device In some embodiments of the present application, the membrane separation is performed in at least four stages; more preferably, the membrane separation is performed using at least one of PTFE, PVDF and PE.

[0081] In some embodiments of the present application, the light component from the de-light unit is distilled in a light component enrichment column (5) to obtain 95-99wt%, preferably 97-99wt% of the light component, which is then introduced into a catalytic hydrogenation device (7) for hydrogenation treatment.

[0082] In some embodiments of the present application, the heavy component removed in the de-heavy column is introduced into a heavy component enrichment column for distillation, and the overhead product from the distillation is returned to the de-heavy column In some embodiments of the present application, the distillation conditions of the heavy component enrichment column include a pressure of 50-101 kPa, a reflux ratio of 0.2-2, and a column bottom operating temperature of 66.5-83.0°C.

[0083] In some embodiments of the present application, the overhead material from the de-light column (1) is exchanged with the column bottom material from the light component enrichment column (5) through a de-light column overhead heat exchanger (2).

[0084] In some embodiments of the present application, the column bottom material from the de-light column (1) is exchanged with the feed material of the de-heavy column (3) through a de-heavy column bottom heat exchanger (4). In some embodiments of the present application, the column bottom material from the de-light column (1) is exchanged with the feed material of the de-heavy column (3) through a de-heavy column bottom heat exchanger (4).

[0085] In order to facilitate the understanding of the present application, a process flow of the present application is provided, which includes: introducing isopropyl alcohol raw material into the de-light column from the middle and upper part of the de-light column; exchanging the overhead vapor phase from the de-light column through the de-light column overhead heat exchanger, part of which is returned to the de-light column as reflux liquid, and the other part is introduced into the light component enrichment column after being decompressed in a decompressor; after being separated in the light component enrichment column, part of the column bottom product is directly returned to the feed line of the de-light column, and the other part is exchanged with the de-light column overhead heat exchanger and then vaporized to enter the column bottom of the light component enrichment column. The overhead product of the light component enrichment column is partially directly discharged out of the boundary zone, partially returned to the light component enrichment column as reflux liquid, and the other part is pressurized and introduced into the catalytic hydrogenation device from the bottom side, and the pressurized hydrogen is also introduced into the catalytic hydrogenation device from the bottom. At the top of the catalytic hydrogenation device, a gas-liquid mixture after hydrogenation is obtained, which is separated by a gas-liquid separator, the gaseous product (mainly hydrogen) is returned to the hydrogen inlet, and the liquid product is mixed with the raw material of the de-light column and then introduced into the catalytic hydrogenation device.

[0086] ​The liquid from the column bottom of the light-removing column is adjusted by a pressure reducing regulator, and then is heated exchanged by the column bottom heat exchanger of the heavy-removing column, and then enters the dehydration device. The column bottom reflux liquid of the light-removing column is heated by the column bottom heat exchanger of the light-removing column, and then enters the light-removing column in the form of vapor phase. The isopropyl alcohol product after dehydration directly enters the heavy-removing column from the middle and lower part of the heavy-removing column. After separation by the heavy-removing column, the column bottom product of the heavy-removing column is directly discharged, and part of the column bottom product of the heavy-removing column enters the heavy component enrichment column from the middle and lower part of the heavy component enrichment column, and part of the column bottom product of the heavy-removing column is heated exchanged by the column bottom heat exchanger of the heavy-removing column, and then enters the heavy-removing column in the form of vapor phase. The top product of the heavy-removing column is heated exchanged by the top heat exchanger of the heavy-removing column, and then enters the light-removing column from the middle and upper part of the light-removing column. The side product of the heavy-removing column is sequentially subjected to ion exchange and membrane separation to obtain the super-clean high-purity isopropyl alcohol product. The column bottom product of the heavy-removing column entering the heavy component enrichment column is separated by the heavy component enrichment column, and the column bottom product of the heavy component enrichment column is the isopropyl alcohol product with high heavy component content, and the top product of the heavy component enrichment column is combined with the dehydration product of the heavy-removing column to enter the heavy-removing column.

[0087] The advantages of the present application will be illustrated by the following examples, but the present application is not limited to the following examples.

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

[0089] Example 1

[0090] In the present application, the reagents and raw materials used in the present application are commercially available, the catalysts used in the examples and comparative examples are the same copper-based catalysts, the product purity of the examples is detected by HPLC, the water content is detected by Karl Fischer titrator, the metal ions are detected by ICP-MS, and the particle number is detected by a particle counter. Figure 1The shown purification system of isopropanol is implemented, a batch of industrial grade isopropanol, measured purity of isopropanol is 99.1% by weight, the water content is 1250ppm, which contains 370ppm of acetone. The upper middle part (20% from top to bottom) of the light removal column is punched in, the operating pressure of the light removal column is 160kPa, the reflux ratio is 17, at this time, the operating temperature of the column bottom of the light removal column is 94.8℃; After separation by the light removal column, the vapor phase at the top of the column is heat exchanged by the overhead heat exchanger of the light removal column, part of which returns to the light removal column as reflux liquid, and the other part enters the upper middle part (30% from top to bottom) of the light component enrichment column after being reduced in pressure by the pressure reducer. The operating pressure of the light component enrichment column is 60kPa, the reflux ratio is 1, at this time, the operating temperature of the column bottom of the light component enrichment column is 70.1℃. After separation by the light component enrichment column, part of the column bottom product (20%) is directly returned to the isopropanol raw material feed line of the light removal column, and part is heat exchanged by the overhead heat exchanger of the light removal column and then vaporized into the column bottom of the light component enrichment column. The overhead product of the light component enrichment column, part of the non-condensable gas is directly discharged out of the boundary, part (44.4%) is returned to the light component enrichment column as reflux liquid, and part is pressurized and enters the bottom side feed port of the catalytic hydrogenation device. The mass ratio of the part discharged out of the boundary and the part entering the catalytic hydrogenation device is 3%:97%. The catalytic hydrogenation is carried out under the conditions of space velocity 0.5h -1 , hydrogen / gas feed port 10 (based on ketone compounds) is 8 (molar ratio), reaction temperature is 115℃, and pressure is 6MPa. After the above-mentioned catalytic hydrogenation process (catalyst is copper-based catalyst, same below), the acetone content in the overhead product of the light component enrichment column can be reduced from 5250ppm to 72ppm. After the gas-liquid separation of the gaseous and liquid mixed products after hydrogenation, the gaseous products are returned to the hydrogen feed line for repeated use, and the liquid crude products are together with the industrial grade isopropanol into the light removal column.

[0091] The liquid from the bottom of the light-removing column is adjusted by decompression, and then exchanged with the heat exchanger of the bottom of the heavy-removing column, 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 (from bottom to top 20%) of the heavy-removing column. The operating pressure of the heavy-removing column is 101 kPa, and the reflux ratio is 1.5. At this time, the operating temperature of the bottom of the heavy-removing column is 82.5°C. After the treatment of the heavy-removing column, part of the product (10%) of the bottom of the heavy-removing column is directly discharged, and part of the product enters the heavy component enrichment column from the middle and lower part (from bottom to top 30%) of the heavy component enrichment column, and then enters the heavy-removing column in vapor phase after being exchanged with the heat exchanger of the bottom of the light-removing column. The product at the top of the heavy-removing column is exchanged with the heat exchanger at the top of the heavy-removing column, and then enters the middle and upper part (from top to bottom 30%) of the light-removing column. The product at the bottom of the heavy-removing column enters the heavy component enrichment column, and the operating pressure of the heavy component enrichment column is 70 kPa, and the reflux ratio is 1. At this time, the operating temperature of the bottom of the heavy component enrichment column is 73.5°C. After separation under the separation conditions, the product at the bottom of the heavy component enrichment column is high in heavy component content, and the product at the top of the heavy component enrichment column is combined with the feed of the heavy-removing column after dehydration and enters the heavy-removing column.

[0092] The side product of the heavy-removing column is sequentially subjected to ion exchange and membrane separation to obtain ultra-clean high-purity isopropyl alcohol product. The ion exchange uses mixed bed resin (including hydrogen type strong acid cation exchange resin and hydrogen-oxygen type strong base anion exchange resin, and the mass ratio is 1:1), and the material of the membrane separation is PTFE, which is filtered by four levels of 200 nm, 100 nm, 50 nm and 30 nm to obtain ultra-clean high-purity isopropyl alcohol. The product purity is 99.998%, the water content is 32 ppm, the recovery rate is 92.9%, the single metal ion in the product is ≤10 ppt, and the microparticles (≥50 nm) are ≤10 / ml.

[0093] Example 2

[0094] This example uses the method as Figure 1The shown purification system of isopropanol is implemented, a batch of industrial grade isopropanol, measured isopropanol purity of 98.5wt%, the water content is 6200ppm, which contains 1800ppm of acetone. The upper part of the light removal column (from top to bottom 20%) is hit, the operating pressure of the light removal column is 200kPa, the reflux ratio is 8, at this time, the operating temperature of the light removal column is 100.7℃; After separation by the light removal column, the vapor phase at the top of the column is heat exchanged by the light removal column overhead heat exchanger, part of which returns to the light removal column as reflux liquid, and the other part is reduced in pressure by the pressure reducer and enters the upper part of the light component enrichment column (from top to bottom 30%). The operating pressure of the light component enrichment column is 90kPa, the reflux ratio is 2, at this time, the operating temperature of the light component enrichment column is 79.5℃. After separation by the light component enrichment column, part of the column product (15%) is directly returned to the isopropanol raw material feed line of the light removal column, and part is heat exchanged by the overhead heat exchanger of the light removal column and then vaporized into the column of the light component enrichment column. The overhead product of the light component enrichment column is partially discharged outside the boundary, partially (60%) returned to the light component enrichment column as reflux liquid, and partially pressurized and fed into the bottom side feed port of the catalytic hydrogenation device. The pressurized hydrogen is also fed into the bottom of the catalytic hydrogenation device. The mass ratio of the discharge outside the boundary and the catalytic hydrogenation device is 4%:96%. The catalytic hydrogenation is carried out under the conditions of space velocity 0.7h -1 , hydrogen / gas-liquid separation device 10 feed (ketone compounds) is 8 (molar ratio), reaction temperature is 100℃, pressure is 8MPa. After the above-mentioned catalytic hydrogenation process, the acetone content in the overhead product of the light component enrichment column can be reduced from 27000ppm to 120ppm. After the gas-liquid separation of the gas-liquid separation device, the gas phase product returns to the hydrogen feed line for repeated use, and the liquid phase crude product enters the light removal column together with the industrial grade isopropanol.

[0095] The liquid from the kettle of the light component removal column is adjusted by decompression, and then is heated by the heat exchanger of the kettle of the heavy component removal column, and then is introduced into the dehydration adsorption device. The dehydration device uses 4A molecular sieve. After the dehydration treatment, the product is introduced from the middle and lower part (from bottom to top 20%) of the heavy component removal column. At this time, the operating pressure of the heavy component removal column is 150 kPa, and the reflux ratio is 2, and the operating temperature of the kettle of the heavy component removal column is 92.8°C. After the treatment of the heavy component removal column, the part (10%) of the product from the kettle of the heavy component removal column is directly discharged, and the other part is heated by the heat exchanger of the kettle of the heavy component removal column, and then is introduced into the heavy component enrichment column in the form of gas phase. The product from the top of the heavy component removal column is heated by the heat exchanger of the top of the heavy component removal column, and then is introduced from the middle and upper part (from top to bottom 30%) of the light component removal column. The product from the kettle of the heavy component removal column is separated in the heavy component enrichment column under the operating pressure of 80 kPa and the reflux ratio of 2, and at this time, the operating temperature of the kettle of the heavy component enrichment column is 76.7°C. After the separation in the heavy component enrichment column, the product from the kettle is the isopropyl alcohol with high content of heavy components, and the product from the top is combined with the feed of the heavy component removal column after the dehydration treatment.

[0096] The product from the heavy component removal column is sequentially subjected to ion exchange and membrane separation to obtain the super-clean high-purity isopropyl alcohol. The ion exchange uses mixed bed resin (including hydrogen type strong acid cation exchange resin and hydrogen-oxygen type strong base anion exchange resin, and the mass ratio is 1:1.2), and the membrane separation uses PTFE, and after four-stage filtration of 200 nm, 100 nm, 50 nm and 30 nm, the super-clean high-purity isopropyl alcohol is obtained. The product has a purity of 99.996%, a water content of 47 ppm, a recovery rate of 91.2%, and a single metal ion in the product of ≤10 ppt and a particle (≥50 nm) of ≤10 pieces / ml.

[0097] Example 3

[0098] Different from example 1, the operating pressure of the light component removal column is 130 kPa, and the reflux ratio is 5, and at this time, the operating temperature of the kettle of the light component removal column is 87°C; the operating pressure of the light component enrichment column is 50 kPa, and the reflux ratio is 0.3, and the operating temperature of the kettle of the light component enrichment column is 68°C. The catalytic hydrogenation is carried out under the conditions of space velocity 0.2 h-1, hydrogen / the feed of the bottom lateral inlet 10 (calculated by the ketone compound) 3 (molar ratio), reaction temperature 80°C and pressure 3 MPa. After the above catalytic hydrogenation process, the content of acetone in the product from the top of the light component enrichment column is reduced from 6300 ppm to 198 ppm or less. -1

[0099] ​The operating pressure of the heavy component removal column is 125 kPa, the reflux ratio is 5, and the operating temperature of the column bottom of the heavy component removal column is 86.2°C. The operating pressure of the heavy component removal column is 55 kPa, the reflux ratio is 0.5, and the operating temperature of the column bottom of the heavy component removal column is 68°C.

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

[0101] Example 4

[0102] Different from Example 1, the operating pressure of the light component removal column is 160 kPa, the reflux ratio is 0.5, and the operating temperature of the column bottom of the light component removal column is 94.8°C.

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

[0104] Example 5

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

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

[0107] Example 6

[0108] Different from Example 1, the operating pressure of the heavy component removal column The overhead product of the heavy component removal column is not returned to the light component removal column 1.

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

[0110] Example 7

[0111] Different from Example 1, the light component removal pipeline 2 is directly connected to the catalytic hydrogenation device without the light component removal column.

[0112] Ultra clean high purity isopropanol was obtained with product purity 99.988%, water content = 68 ppm, recovery = 93.1%, single metal ion in product < 10 ppt, and particulates (> 50 nm) < 10 per ml.

[0113] Example 8

[0114] Unlike Example 1, the heavy component enrichment column was not provided, and the heavy component column was directly discharged from the column bottom to the system.

[0115] Ultra clean high purity isopropanol was obtained with product purity 99.998%, water content = 30 ppm, recovery = 87.1%, single metal ion in product < 10 ppt, and particulates (> 50 nm) < 10 per ml.

[0116] Example 9

[0117] Unlike Example 1, the isopropanol feed line 1 was provided at a position 60% from the top of the light component column.

[0118] Ultra clean high purity isopropanol was obtained with product purity 99.993%, water content = 45 ppm, recovery = 92.2%, single metal ion in product < 10 ppt, and particulates (> 50 nm) < 10 per ml.

[0119] Example 10

[0120] Unlike Example 1, the heavy component column overhead line 26 was provided at a position 70% from the top of the light component column.

[0121] Ultra clean high purity isopropanol was obtained with product purity 99.996%, water content = 34 ppm, recovery = 92.5%, single metal ion in product < 10 ppt, and particulates (> 50 nm) < 10 per ml.

[0122] Example 11

[0123] Unlike Example 1, the heavy component column heavy component line 27 was connected to a position 70% from the bottom of the heavy component enrichment column.

[0124] Ultra clean high purity isopropanol was obtained with product purity 99.996%, water content = 36 ppm, recovery = 92.6%, single metal ion in product < 10 ppt, and particulates (> 50 nm) < 10 per ml.

[0125] Example 12

[0126] Unlike Example 1, the dehydration adsorption device was connected to a position 50% from the bottom of the heavy component column.

[0127] The super-clean high-purity isopropyl alcohol was obtained, wherein the product purity was 99.991%, the water content was 45 ppm, the recovery rate was 92.4%, the single metal ion in the product was ≤10 ppt, and the microparticles (≥50 nm) were ≤10 pieces / ml.

[0128] Comparative Example 1

[0129] Different from Example 1, no catalytic hydrogenation device was arranged.

[0130] The super-clean high-purity isopropyl alcohol was obtained, wherein the product purity was 99.969%, the water content was 240 ppm, the recovery rate was 92.8%, the single metal ion in the product was ≤10 ppt, and the microparticles (≥50 nm) were ≤10 pieces / ml.

[0131] Comparative Example 2

[0132] Different from Example 1, the positions of the heavy-removing tower and the water-removing adsorption device were reversed, that is, the isopropyl alcohol raw material was sequentially subjected to light-removing, heavy-removing, water-removing, ion-removing and microparticle-removing to obtain the purified isopropyl alcohol.

[0133] The super-clean high-purity isopropyl alcohol was obtained, wherein the product purity was 99.994%, the water content was 27 ppm, the recovery rate was 92.5%, the single metal ion in the product was ≤1000 ppt, and the microparticles (≥50 nm) were ≤500 pieces / ml.

[0134] The preferred embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various specific technical features in any suitable manner. In order to avoid unnecessary repetition, the present application does not further describe various possible combination manners. However, these simple modifications and combinations should also be regarded as the disclosed content of the present application and belong to the protection scope of the present application.

Claims

1. A purification system for isopropanol, characterized in that, The purification system includes: The isopropanol purification unit includes a light-removal sub-unit, a dehydration sub-unit, a heavy-removal sub-unit, an ion-deionization sub-unit, and a microparticle-deionization sub-unit connected in series along the material flow direction, for sequentially removing light, water, heavy, ion, and microparticles from the isopropanol feedstock to obtain purified isopropanol. The removal of light components from the isopropanol feedstock includes the removal of light components containing acetone. The waste liquid recovery unit includes a light component recovery subunit, which is connected to the light component removal subunit so that the light component can enter the light component recovery subunit, where acetone in the light component is converted into isopropanol and then returned to the light component removal subunit. The light component recovery subunit includes a light component enrichment tower (⑤), a catalytic hydrogenation unit (⑧), and a gas-liquid separator (⑩) connected in series. 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 feed line (1) of the lepto-hydrogen unit.

2. The purification system according to claim 1, wherein, The bottom outlet of the light component enrichment tower (⑤) is connected to the isopropanol feed line (1).

3. The purification system according to claim 1, wherein, The gas phase outlet (12) of the gas-liquid separator (⑩) is connected to the hydrogen feed line (13) of the catalytic hydrogenation unit (⑧).

4. The purification system according to claim 1, characterized in that, The waste liquid recovery unit also includes a heavy component recovery subunit. The inlet of the heavy component recovery subunit is connected to the heavy component discharge pipeline (27) of the de-heavy component subunit. The top of the heavy component recovery subunit is connected to the de-heavy component subunit.

5. The purification system according to claim 1, characterized in that, The light component removal unit includes a light component removal tower (①), which is equipped with an isopropanol feedstock pipeline (1) for separating light components from the isopropanol feedstock; The dehydration subunit includes a dehydration adsorption device. The dehydration adsorption device The medium is filled with a desiccant and connected to the light-light removal tower (①), through which the water in the isopropanol after light-light removal is removed; The dehydration subunit includes a device connected to the dehydration adsorption apparatus. Deweight tower The deweight tower Used to remove the weight of dehydrated isopropanol; The detachment sub-unit includes the connection to the deweight removal tower. Ion exchange adsorption device The ion exchange adsorption device Used to adsorb metal cations and anions from isopropanol after weight removal; The demicroparticle unit includes a device connected to the ion exchange adsorption apparatus. membrane separation device The membrane separation device Used to remove particles from isopropanol after deionization.

6. The purification system according to claim 5, characterized in that, The deweight tower The top of the tower is connected to the light removal tower (①) via the heavy removal tower top extraction pipeline (26); and / or The isopropanol feedstock pipeline (1) is located in the upper middle part of the light removal tower (①); and / or The light component discharge pipeline (2) is connected to the feed inlet in the upper middle 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 side inlet (10) of the catalytic hydrogenation unit (⑧), and the hydrogen feed line (13) is connected to the bottom of the catalytic hydrogenation unit (⑧); and / or The dehydration adsorption device The discharge port and the deweight removal tower The feed inlet in the middle and lower part is connected; and / or The recombinant fraction recovery subunit includes a recombinant fraction enrichment tower. De-weight tower The recombinant discharge pipeline (27) and the recombinant enrichment tower The feed inlet in the middle and lower part is connected to the recombinant enrichment tower. The top extraction pipeline (30) and the de-weighting tower The feed inlet is connected.

7. The purification system according to claim 6, characterized in that, The deweight tower The top of the tower is connected to the feed inlet in the upper middle part of the light removal tower (①) through the top extraction pipeline (26) of the heavy removal tower.

8. The purification system according to claim 4, characterized in that, The purification system includes a heat exchange unit, which comprises a light-weight removal tower (①), a top heat exchanger (②), and a heavy-weight removal tower. Tower Boiler Heat Exchanger in, The heat exchanger (②) at the top of the light component removal tower (①) is used to achieve heat exchange between the top material of the light component removal tower (①) and the bottom material of the light component enrichment tower (⑤); De-weight tower Tower Boiler Heat Exchanger The bottom discharge of the light-weight removal tower (①) is used to achieve the same effect as the heavy-weight removal tower. Heat exchange of materials in the bottom of the tower.

9. A method for purifying isopropanol, characterized in that, The purification method employs the isopropanol purification system according to any one of claims 1-8, comprising: Isopropanol feedstock is fed into the lepto-ion removal unit, such that the isopropanol feedstock undergoes sequential lepto-ion removal, dehydration, deweight removal, deionization, and demicronization to obtain purified isopropanol; wherein, the lepto-ion removal of the isopropanol feedstock includes the removal of light components containing acetone; The light component recovery subunit converts acetone in the light component into isopropanol, and the isopropanol is returned to the lepto-removal subunit.

10. The purification method according to claim 9, wherein, The light components from the leptin removal unit are distilled in a light component enrichment tower (⑤), and the top product of the tower enters a catalytic hydrogenation unit (⑧) for hydrogenation treatment. After gas-liquid separation in a gas-liquid separator (⑩), the liquid phase is returned to the leptin removal unit.

11. The purification method according to claim 10, wherein, The distillation conditions for the light component enrichment column (⑤) include: a pressure of 50-101 kPa, a reboiler operating temperature of 66.0℃~82.5℃, and a reflux ratio of 0.2-2; and / or The catalyst for hydrogenation is a copper-based catalyst; and / or The conditions for hydrotreating include a space velocity of 0.2-0.8 h⁻¹. -1 The molar ratio of hydrogen to the bottom side feed inlet (10) is 2-10, the temperature is 80-120℃, and the pressure is 3-10Mpa.

12. The purification method according to claim 9, wherein, The isopropanol raw material contains not less than 98% by weight of isopropanol; and / or The removal of light components includes distillation in a light component removal column (①), the distillation conditions of which include: pressure 130-200 kPa, reboiler operating temperature 86.5℃~101℃, and reflux ratio 2-20; and / or The dehydration includes a dehydration adsorption device. Adsorption and dehydration are carried out in the adsorption device. The water-absorbing agent in the solution is selected from molecular sieve membranes and / or molecular sieves; and / or The deweighting process includes the deweighting tower. Distillation is carried out in the deweighting column. The distillation conditions include: a pressure of 101-150 kPa, a reboiler operating temperature of 82.5-92.5℃, and a reflux ratio of 0.2-5; and / or The detachment is included in the ion exchange adsorption device. Ion exchange resin adsorption is used; and / or The demicronization includes the membrane separation device. Membrane separation is performed in the process.

13. The purification method according to claim 12, wherein, The isopropanol raw material also contains at least one of water, n-propanol, isopropyl ether, acetone, methyl ethyl ketone, and isobutanol; and / or The desiccant is a NaA type pervaporation molecular sieve membrane and / or a type A molecular sieve; and / or The ion exchange resin is a mixed resin comprising a hydrogen-form strong acid cation exchange resin and a hydroxide-form strong base anion exchange resin; and / or The demicronization includes the membrane separation device. Membrane separation is performed using at least four stages of membrane separation.

14. The purification method according to claim 13, wherein, The mass ratio of hydrogen-form strong acid cation exchange resin to hydroxide-form strong base anion exchange resin is 3:1-1:3; and / or The membrane separation material is at least one of PTFE, PVDF and PE.

15. The purification method according to any one of claims 9, wherein, The light components from the lepto-hydrogen unit are distilled in a light component enrichment tower (⑤), and 95-99 wt% of the light components are then fed into a catalytic hydrogenation unit (⑧) for hydrogenation treatment. and / or De-weight tower The recombinant components removed from the medium enter the recombinant enrichment tower. The distillate from the top of the column after rectification is returned to the deweighting column. and / or The material at the top of the light component removal tower (①) is exchanged with the material at the bottom of the light component enrichment tower (⑤) through the heat exchanger at the top of the light component removal tower (②); and / or Through the heat exchanger of the deweighting tower bottom The bottom discharge of the light-removing tower (①) is combined with that of the heavy-removing tower. The feed material is subjected to heat exchange.

16. The purification method according to claim 15, wherein, The light components from the lepto-feed unit are distilled in a light component enrichment tower (⑤), and 97-99 wt% of the light components are then fed into a catalytic hydrogenation unit (⑧) for hydrogenation treatment. and / or Recombination enrichment tower The distillation conditions include: pressure of 50-101 kPa, reflux ratio of 0.2-2, and reboiler operating temperature of 66.5-83.0℃.

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