Method for purifying industrial grade isopropanol

Abstract

The present application relates to the field of preparation of high-end wet electronic chemicals for integrated circuits, and in particular to a method for purifying industrial-grade isopropanol. The method comprises: dehydrating and de-lighting industrial-grade isopropanol to obtain a light liquid phase and a heavy liquid phase; subjecting the light liquid phase to flash evaporation treatment to obtain a second liquid phase, and returning the second liquid phase to the de-lighting step after catalytic hydrogenation; and subjecting the heavy liquid phase to de-heavying. The present application greatly improves the recovery rate of purified isopropanol products by subjecting the material obtained after dehydration to flash evaporation + catalytic hydrogenation under the condition of ensuring the technical indicators such as product purity and water content.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of preparation of high-end wet electronic chemicals for integrated circuits, in particular to a purification method of industrial-grade isopropanol. BACKGROUND

[0002] With the rapid development of China's integrated circuit industry, the demand and requirements for ultra-clean high-purity reagents have been further improved. In the entire integrated circuit manufacturing industry, ultra-clean high-purity reagents are mainly used for chip cleaning and drying, and the quality of the products has an important influence on the yield of the chip.

[0003] Ultra-clean high-purity isopropanol is an organic wet electronic chemical with the largest amount of use, and is often used as the last cleaning of the chip, so there are very strict requirements on the product quality. In addition to product purity, organic impurities and water content, there are also very strict requirements on the residues of anions and cations and microparticles. And with the further breakthrough of chip manufacturing process, higher requirements for the product quality of ultra-clean high-purity isopropanol are put forward.

[0004] For the preparation process of ultra-clean high-purity isopropanol, some documents and patents have been reported. For example, CN 114870420A reports a production method of high-purity electronic-grade isopropanol containing a dehydration treatment device, a microfilter, an anion and cation removal device, a rectifying tower and a nanofiltration. However, the product of this process can only reach the SEMI G4 standard, and the rectification steps in the process result in a low recovery rate of electronic-grade isopropanol. For example, CN 101362675B reports a method for preparing ultra-clean high-purity isopropanol from industrial-grade isopropanol. The method adopts complexation, dehydration, microfiltration, rectification, nanofiltration and other steps to finally obtain ultra-clean high-purity isopropanol products. In the process, four-stage rectification is needed to remove organic impurities. Similarly, CN 103613486A also reports a preparation method of ultra-clean high-purity isopropanol, which adopts multi-stage continuous rectification to remove organic impurities. The above preparation methods have poor removal efficiency of organic impurities, and seriously affect the single-pass yield of ultra-clean high-purity isopropanol, and the production efficiency is low. SUMMARY

[0005] The purpose of the present application is to overcome the problems of poor removal efficiency of organic impurities and serious influence on the single-pass yield of ultra-clean high-purity isopropanol in the prior art, and to provide a purification method of industrial-grade isopropanol, which has the characteristics of short process flow, high product recovery rate and good product quality.

[0006] In order to achieve the above-mentioned purpose, the present application provides a purification method of industrial-grade isopropanol, which comprises: dehydrating and removing light components of industrial-grade isopropanol to obtain a light liquid phase and a heavy liquid phase; the light liquid phase is subjected to flash evaporation treatment to obtain a second liquid phase, and the second liquid phase is returned to the light component removal after catalytic hydrogenation; and the heavy liquid phase is subjected to heavy component removal.

[0007] Through the technical scheme, the application has the following advantages:

[0008] The application greatly improves the recovery rate of purified isopropyl alcohol product under the condition of ensuring product purity, water content and other technical indexes by performing flash evaporation + catalytic hydrogenation on the material obtained by sending into the light removal tower after dehydration. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a preferred embodiment of the application, which is a flow chart of industrial grade isopropyl alcohol purification.

[0010] BRIEF DESCRIPTION OF DRAWINGS

[0011] ①permeation vaporization device ②light removal tower

[0012] ③flash evaporation tank ④catalytic hydrogenation device

[0013] ⑤heavy removal tower ⑥ion removal tower

[0014] ⑦particulate removal device 1, industrial isopropyl alcohol

[0015] 2, product after dehydration 3, light removal tower kettle liquid

[0016] 4, light removal tower overhead liquid 5, flash evaporation vapor phase

[0017] 6, flash evaporation liquid phase 7, product after catalytic hydrogenation

[0018] 8, heavy removal tower kettle liquid 9, heavy removal tower overhead liquid

[0019] 10, ion removal product 11, purified isopropyl alcohol product DETAILED DESCRIPTION

[0020] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as the exact dimensions are not considered critical for the application. The endpoints of the ranges and the values disclosed herein should be understood to be open-ended ranges. The ranges disclosed herein are also intended to cover any and all sub-ranges of the ranges. For example, a stated range of 1 to 10 should be considered to include any and all sub-ranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all sub-ranges beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less, as well as all sub-ranges beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less, each sub-range including all values from the minimum up to and including the maximum value. For another example, a stated range of 1 to 10 should be considered to include any and all sub-ranges of 1 to 10, e.g., 7 to 8, 8 to 9 or 9 to 10, each sub-range including all values from the minimum up to and including the maximum value.

[0021] The application provides an industrial grade isopropyl alcohol purification method, which comprises: industrial grade isopropyl alcohol dehydration, light removal to obtain light liquid phase and heavy liquid phase; the light liquid phase is subjected to flash evaporation treatment to obtain a second liquid phase, and the second liquid phase is returned to the light removal after catalytic hydrogenation; and the heavy liquid phase is subjected to heavy removal.

[0022] The application greatly improves the recovery rate of purified isopropyl alcohol product under the conditions of ensuring product purity, water content and other technical indexes by performing flash evaporation + catalytic hydrogenation on the material obtained by sending into the light-removing tower after dehydration.

[0023] According to a preferred embodiment of the application, the conditions of the flash evaporation treatment include: the pressure is 20-80 kPaA, and / or the control temperature of the flash evaporation liquid phase is 46.5-76.2℃.

[0024] According to a preferred embodiment of the application, the conditions of the flash evaporation treatment include: the pressure is 40-60 kPaA, and / or the control temperature of the flash evaporation liquid phase is 60.5-69.5℃. By adopting the foregoing preferred scheme, the light components can be better removed, and the recovery rate of isopropyl alcohol is improved.

[0025] According to a preferred embodiment of the application, the catalyst of the catalytic hydrogenation is a solid catalyst, preferably a copper-based catalyst. By adopting the foregoing preferred scheme, the residual acetone can be converted into isopropyl alcohol, and the purity of the purified isopropyl alcohol is improved.

[0026] According to a preferred embodiment of the application, the conditions of the catalytic hydrogenation include: the reaction pressure is 3-10 MpaA; and / or the reaction temperature is 80℃-120℃; and / or the space velocity is 0.2-0.8h -1 , and / or the molar ratio of hydrogen gas / second liquid phase (calculated based on ketone compounds) is 2-10. By adopting the foregoing preferred scheme, the trace amount of acetone in the light-removing product can be converted into isopropyl alcohol, the content of acetone in the light-removing tower is reduced, and the product purity of the purified isopropyl alcohol is improved.

[0027] According to a preferred embodiment of the application, the conditions of the light-removing include: the pressure is 101-200 kPa; and / or the reflux ratio is 2-20; and / or the operating temperature of the column bottom is 82.8℃-100.5℃.

[0028] According to a preferred embodiment of the application, the conditions of the heavy-removing include: the pressure is 101-200 kPa; and / or the reflux ratio is 0.2-5; and / or the operating temperature of the column top is 82.5℃-100.2℃.

[0029] According to a preferred embodiment of the application, the method further includes: after the heavy liquid phase is removed, the purified isopropyl alcohol is obtained by sequentially removing ions and microparticles.

[0030] According to a preferred embodiment of the application, the ion removal adopts the ion exchange resin adsorption mode.

[0031] According to a preferred embodiment of the present application, the ion exchange resin is a mixed resin comprising 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. By adopting the foregoing preferred scheme, residual trace amounts of anions and cations in the product can be efficiently removed.

[0032] According to a preferred embodiment of the present application, the particle removal is in the form of filtration.

[0033] According to a preferred embodiment of the present application, the filtration preferably adopts a filter core made of at least one of PFA, PTFE and PP. By adopting the foregoing preferred scheme, particles in the isopropyl alcohol product can be better removed, so as to meet the technical requirement that the number of particles with a size of ≥50 nm is ≤10 / ml.

[0034] According to a preferred embodiment of the present application, the filtration is performed in a multi-stage series mode, and preferably, is performed in a mode of at least three stages in series. The present application is described by taking a mode of four stages in series (the filter cores are made of PFA, and the specifications are 200 nm, 100 nm, 50 nm and 15 nm in order) to illustrate the advantages of the present application.

[0035] According to a preferred embodiment of the present application, the dehydration is performed in a mode of molecular sieve adsorption and / or pervaporation.

[0036] According to a preferred embodiment of the present application, the molecular sieve is at least one of a 3A type molecular sieve, a 4A type molecular sieve and a 5A type molecular sieve.

[0037] According to a preferred embodiment of the present application, the pervaporation adopts a molecular sieve membrane, and preferably, the operation of the pervaporation comprises: an absolute pressure of 1-8 bar. By adopting the foregoing preferred scheme, the water content in the isopropyl alcohol product can be removed, so as to meet the technical requirement that the water content is ≤100 ppm.

[0038] According to a preferred embodiment of the present application, the content of isopropyl alcohol in the industrial grade isopropyl alcohol is ≥98 wt%, and preferably, ≥99.5 wt%.

[0039] According to a preferred embodiment of the present application, the industrial grade isopropyl alcohol further contains at least one of water, methanol, ethanol, n-propanol, isopropyl ether, acetone, methyl ethyl ketone and isobutyl alcohol.

[0040] According to a preferred embodiment of the present application, the second liquid phase returns to the light removal after catalytic hydrogenation, and then is mixed with the material after the dehydration treatment to perform the light removal together. By adopting the foregoing preferred scheme, the recovery rate of the purified isopropyl alcohol product can be improved.

[0041] According to a preferred embodiment of the present invention, the purity of isopropanol in the purified industrial-grade isopropanol product is above 99.99%, the water content is ≤100ppm, and preferably, the single metal ion in the product is ≤10ppt, and the particles with a diameter ≥50nm are ≤10 / ml.

[0042] like Figure 1 As shown, the present invention provides an exemplary description of a preferred embodiment, the illustrated device comprising:

[0043] The discharge pipeline of the pervaporation unit ① is connected to the feed pipeline of the light-weight removal tower ②. The top discharge pipeline of the light-weight removal tower ② is connected to the feed inlet of the flash tank ③. The liquid phase discharge outlet of the flash tank ③ is connected to the bottom feed inlet of the catalytic hydrogenation unit ④. The top discharge outlet of the catalytic hydrogenation unit ④ is connected to the feed pipeline of the light-weight removal tower ②. The bottom discharge pipeline of the light-weight removal tower ② is connected to the feed pipeline of the heavy-weight removal tower ⑤. The top discharge pipeline of the heavy-weight removal tower ⑤ is connected to the top feed inlet of the deionization sub-tower ⑥. The bottom of the deionization sub-tower ⑥ is connected to the de-particle removal unit ⑦.

[0044] The preparation process of isopropanol includes:

[0045] Industrial-grade isopropanol 1 enters the pervaporation unit ①. After dehydration on the concentration side, product 2 enters the light-weight removal tower ②. The overhead liquid 4 of the light-weight removal tower enters the flash tank ③ for flash evaporation. The flash vapor phase 5 is discharged from the unit. The flash liquid phase 6 is hydrogenated by the catalytic hydrogenation unit ④ to obtain the catalytically hydrogenated product 7, which is returned to the feed of the light-weight removal tower ②. The bottom liquid 3 of the light-weight removal tower enters the heavy-weight removal tower ⑤. The overhead liquid 9 of the heavy-weight removal tower passes through the deionization tower ⑥ to obtain the deionized product 10. The deionized product 10 passes through the demicronization unit ⑦ to finally obtain the purified isopropanol product 11. The bottom liquid 8 of the heavy-weight removal tower is discharged from the unit.

[0046] In this invention, "tower top" and "top" refer to the "0-30%" portion of the volume of each device from top to bottom; "tower bottom" and "bottom" refer to the "70-100%" portion of the volume of each device from top to bottom.

[0047] The present invention will be described in detail below through examples. All reagents and raw materials used in the present invention are commercially available.

[0048] In this invention, the catalytic hydrogenation apparatus of the embodiments is filled with the same copper-based catalyst, the purity of the products is detected by HPLC, the moisture content is determined by Karl Fischer titration, the metal ions are determined by ICP-MS, and the particle number is determined by an online particle counter.

[0049] Example 1

[0050] A batch of industrial-grade isopropanol, with a purity of 99.5%, a water content of 475 ppm, and an acetone content of 215 ppm, was used. First, pervaporation was employed to remove water from the industrial-grade isopropanol at an operating pressure (absolute) of 6 bar. The dehydrated product underwent a light-light component removal process at an operating pressure (absolute) of 125 kPa, a reflux ratio of 10, and a controlled reboiler temperature of 88.3°C. The top product from the light-light component removal process was then flash-distilled at an operating pressure (absolute) of 50 kPa and a controlled temperature of 65.4°C for the flash-distilled liquid phase. The flash-distilled liquid phase was then subjected to catalytic hydrogenation (using a copper-based catalyst, the same below) at an operating pressure (absolute) of 8 MPa, a reaction temperature controlled at 110°C, and a space velocity of 0.6 h⁻¹. -1 The molar ratio of hydrogen to the flash-evaporated liquid phase (based on ketone compounds) is 6. The hydrogenated product and the dehydrated product are then subjected to a second light-weight removal process. The product from the bottom of the light-weight removal process is then subjected to a heavy-weight removal process. The operating pressure (absolute pressure) for the heavy-weight removal process is 125 kPa, the reflux ratio is 2, and the operating temperature at the top of the column is controlled at 87.4℃. The resulting top product is then subjected to deionization (using a 1:1 mass ratio of hydrogen-form strong acid cation exchange resin and hydroxide-form strong base anion exchange resin) and departicle removal (using a four-stage series of PFA filter cartridges with successively 200 nm, 100 nm, 50 nm, and 15 nm wavelengths) to obtain ultra-clean, high-purity isopropanol.

[0051] The ultra-clean high-purity isopropanol product was tested and found to have a purity of 99.998%, a water content of 45 ppm, a single metal ion content of ≤10 ppt, a particle size (≥50 nm) content of ≤10 particles / ml, and a recovery rate of 89.3% (recovery rate = (yield of ultra-clean high-purity isopropanol / feed amount of industrial grade isopropanol) * 100%).

[0052] Example 2

[0053] A batch of industrial-grade isopropanol, with a purity of 99.5%, a water content of 475 ppm, and an acetone content of 215 ppm, was used. First, pervaporation was employed to remove water from the industrial-grade isopropanol at an operating pressure (absolute) of 2 bar. The dehydrated product underwent a light-light component removal process at an operating pressure (absolute) of 150 kPa, a reflux ratio of 10, and a controlled reboiler temperature of 92.8 °C. The top product from the light-light component removal process was then flash-distilled at an operating pressure (absolute) of 80 kPa and a controlled temperature of 76.2 °C for the flash-distilled liquid phase. Finally, the flash-distilled liquid phase underwent catalytic hydrogenation at an operating pressure (absolute) of 6 MPa, a reaction temperature controlled at 100 °C, and a space velocity of 0.6 h⁻¹. -1The molar ratio of hydrogen to the flash-evaporated liquid phase (based on ketone compounds) is 6. The hydrogenated product and the dehydrated product are then subjected to a second light-weight removal process. The product from the bottom of the light-weight removal process is then subjected to a heavy-weight removal process. The operating pressure (absolute pressure) for the heavy-weight removal process is 150 kPa, the reflux ratio is 2, and the operating temperature at the top of the column is controlled at 92.3℃. The resulting top product is then subjected to deionization (using a hydrogen-form strong acid cation exchange resin and a hydroxide-form strong base anion exchange resin in a mass ratio of 2:1) and departicle removal (using a four-stage series of PFA filter cartridges with successively 200 nm, 100 nm, 50 nm, and 15 nm wavelengths) to obtain ultra-clean, high-purity isopropanol.

[0054] The ultra-clean high-purity isopropanol product was found to have a purity of 99.994%, a water content of 82 ppm, a single metal ion content of ≤10 ppt, a particle size (≥50 nm) content of ≤10 particles / ml, and a recovery rate of 88.2% (recovery rate = (yield of ultra-clean high-purity isopropanol / feed amount of industrial-grade isopropanol) * 100%).

[0055] Example 3

[0056] A batch of industrial-grade isopropanol, with a purity of 98.5%, a water content of 2500 ppm, and an acetone content of 456 ppm, was used. First, pervaporation was employed to remove water from the industrial-grade isopropanol at an operating pressure (absolute) of 6 bar. The dehydrated product underwent a light-weight removal process at an operating pressure (absolute) of 200 kPa, a reflux ratio of 2, and a controlled reboiler temperature of 100.5 °C. The top product from the light-weight removal process was then flash-distilled at an operating pressure (absolute) of 40 kPa and a controlled temperature of 60.6 °C. The flash-distilled liquid phase was then subjected to catalytic hydrogenation at an operating pressure (absolute) of 8 MPa, a reaction temperature controlled at 110 °C, and a space velocity of 0.6 h⁻¹. -1 The molar ratio of hydrogen to the flash-evaporated liquid phase (based on ketone compounds) is 6. The hydrogenated product and the dehydrated product are then subjected to a second light-weight removal process. The bottom product from the light-weight removal process is then subjected to a heavy-weight removal process. The operating pressure (absolute pressure) for the heavy-weight removal process is 101 kPa, the reflux ratio is 5, and the operating temperature at the top of the column is controlled at 82.5 °C. The resulting top product is then subjected to deionization (the mass ratio of hydrogen-form strong acid cation exchange resin and hydroxide-form strong base anion exchange resin is 1:2) and departicle removal to obtain ultra-clean, high-purity isopropanol.

[0057] The ultra-clean high-purity isopropanol product was tested and found to have a purity of 99.997%, a water content of 95 ppm, a single metal ion content of ≤10 ppt, a particle size (≥50 nm) content of ≤10 particles / ml, and a recovery rate of 89.0% (recovery rate = (yield of ultra-clean high-purity isopropanol / feed amount of industrial-grade isopropanol) * 100%).

[0058] Example 4

[0059] Same as Example 1, except that the operating pressure (absolute pressure) of flash evaporation is 90 kPa and the control temperature of the flash liquid phase is 79.1 °C.

[0060] The ultra-clean high-purity isopropanol product was tested and found to have a purity of 99.992%, a water content of 63 ppm, a single metal ion content of ≤10 ppt, a particle size (≥50 nm) content of ≤10 particles / ml, and a recovery rate of 84.5% (recovery rate = (yield of ultra-clean high-purity isopropanol / feed amount of industrial-grade isopropanol) * 100%).

[0061] Example 5

[0062] Same as Example 1, except that the reaction temperature for catalytic hydrogenation is controlled at 60°C.

[0063] The ultra-clean high-purity isopropanol product was found to have a purity of 99.990%, a water content of 48 ppm, a single metal ion content of ≤10 ppt, a particle size (≥50 nm) content of ≤10 particles / ml, and a recovery rate of 85.9% (recovery rate = (yield of ultra-clean high-purity isopropanol / feed amount of industrial-grade isopropanol) * 100%).

[0064] Example 6

[0065] Same as Example 1, except that the operating pressure (absolute pressure) for pervaporation is 0.5 bar.

[0066] The ultra-clean high-purity isopropanol product was found to have a purity of 99.996%, a water content of 98 ppm, a single metal ion content of ≤10 ppt, a particle size (≥50 nm) content of ≤10 particles / ml, and a recovery rate of 85.3% (recovery rate = (yield of ultra-clean high-purity isopropanol / feed amount of industrial-grade isopropanol) * 100%).

[0067] Comparative Example 1

[0068] Similar to Example 1, except that it does not contain a flash evaporation unit, and the top product of the light-removal treatment tower directly enters the catalytic hydrogenation unit.

[0069] The ultra-clean high-purity isopropanol product was found to have a purity of 99.962%, a water content of 50 ppm, a single metal ion content of ≤10 ppt, a particle size (≥50 nm) content of ≤10 particles / ml, and a recovery rate of 81.2% (recovery rate = (yield of ultra-clean high-purity isopropanol / feed amount of industrial-grade isopropanol) * 100%).

[0070] Comparative Example 2

[0071] Same as Example 1, except that it does not contain a catalytic hydrogenation unit, and the liquid phase after flash evaporation is directly returned to the light-weight product removal process.

[0072] The ultra-clean high-purity isopropanol product was found to have a purity of 99.981%, a water content of 48 ppm, a single metal ion content of ≤10 ppt, a particle size (≥50 nm) content of ≤10 particles / ml, and a recovery rate of 79.5% (recovery rate = (yield of ultra-clean high-purity isopropanol / feed amount of industrial-grade isopropanol) * 100%).

[0073] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for purifying industrial-grade isopropanol, characterized in that, The method includes: dehydrating industrial-grade isopropanol and removing light components to obtain a light liquid phase and a heavy liquid phase; The light liquid phase is flash evaporated to obtain a second liquid phase, which is then catalytically hydrogenated and returned to the light phase removal process. The heavy liquid phase is subjected to heavy removal; the second liquid phase, after catalytic hydrogenation, is returned to the material after light removal and mixed with the material after dehydration for light removal together; The conditions for the flash evaporation treatment include: a pressure of 20-80 kPaA, and / or a controlled temperature of 46.5-76.2℃ for the flash liquid phase; The catalyst for the catalytic hydrogenation is a copper-based catalyst; The conditions for the catalytic hydrogenation include: a reaction pressure of 3-10 MPaA; and a reaction temperature of 80℃-120℃. The conditions for removing light components include: pressure of 101-200 kPa; reflux ratio of 2-20; and reboiler operating temperature of 82.8℃-100.5℃. The conditions for removing heavy materials include: pressure of 101-200 kPa; reflux ratio of 0.2-5; and tower top operating temperature of 82.5℃-100.2℃.

2. The purification method according to claim 1, wherein, The conditions for the flash evaporation treatment include: The pressure is 40-60 kPaA, and / or the controlled temperature of the flash liquid phase is 60.5-69.5℃.

3. The purification method according to claim 1 or 2, wherein, The conditions for the catalytic hydrogenation include: space velocity of 0.2-0.8 h⁻¹. -1 The molar ratio of hydrogen to the second liquid phase is 2-10.

4. The purification method according to claim 1 or 2, wherein, The method further includes: after the heavy liquid phase is deweighted, it is sequentially deionized and demicronized to obtain purified isopropanol.

5. The purification method according to claim 4, wherein, The detachment is adsorbed using an ion exchange resin; and / or The demicronization is performed through filtration.

6. The purification method according to claim 5, wherein, 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 filter uses a filter element made of at least one of PFA, PTFE, and PP.

7. The purification method according to claim 5, 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 filtering is performed in a multi-stage series manner.

8. The purification method according to claim 1 or 2, wherein, The dehydration is carried out by molecular sieve adsorption and / or pervaporation.

9. The purification method according to claim 8, wherein, The molecular sieve is at least one of type 3A, type 4A, and type 5A molecular sieve; and / or The pervaporation process employs a molecular sieve membrane.

10. The purification method according to claim 9, wherein, The pervaporation operation includes an absolute pressure of 1 bar to 8 bar.

11. The purification method according to claim 1 or 2, wherein, The industrial-grade isopropanol contains ≥98% isopropanol by weight; and / or The industrial-grade isopropanol also contains at least one of water, methanol, ethanol, n-propanol, isopropyl ether, acetone, methyl ethyl ketone, and isobutanol.

12. The purification method according to claim 11, wherein, The industrial-grade isopropanol contains ≥99.5% isopropanol by weight.

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