Method and system for preparing ultra-clean high-purity isopropanol

Abstract

The invention relates to the technical field of separation and purification, and discloses a method and system for preparing ultra-clean high-purity isopropanol, and the method comprises the following steps: carrying out first rectification and first adsorption on an isopropanol raw material to remove organic light components and moisture, carrying out first adsorption to remove organic impurities including moisture, alcohol, ether and ketone, and carrying out second rectification to remove organic light components and moisture; the first adsorption is performed before or after the first rectification; second rectification and second adsorption are carried out, the second rectification is used for removing organic heavy components and most of metal cations and anions, and the second adsorption is used for further removing the metal cations and anions; the second adsorption is performed before or after the second rectification; then carrying out third rectification to further remove moisture, alcohol, ether and ketone organic impurities, metal cations and anions; and then filtering to obtain the ultra-clean high-purity isopropanol. According to the method disclosed by the invention, the ultra-clean high-purity isopropanol product with low water content and low alcohol ketone ether impurity content can be obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of separation and purification, and particularly relates to a method and a system for preparing ultra-clean high-purity isopropyl alcohol. Background Art

[0002] Isopropyl alcohol is a commonly used organic solvent, mainly used in the fields of pharmaceuticals, cosmetics, plastics, fragrances, coatings, etc. When used as a solvent for wafer cleaning and drying in the integrated circuit industry, ultra-clean high-purity isopropyl alcohol is required. Ultra-clean high-purity isopropyl alcohol is an important type of organic wet electronic chemicals, used in high-end industries such as solar energy, displays and semiconductors. Therefore, the requirements for organic impurities (alcohols, ketones, ethers), water content, ion content and particulate matter content in isopropyl alcohol are very strict.

[0003] In the existing ultra-clean high-purity isopropyl alcohol production method, dehydration is generally performed first, and then the organic light components (impurities with a lower boiling point than isopropyl alcohol) and the organic heavy components (impurities with a higher boiling point than isopropyl alcohol) are removed by two distillations respectively, and finally the ultra-clean high-purity isopropyl alcohol product is obtained after deionization and degranulation. The high-purity isopropyl alcohol produced by this preparation method still contains a certain amount of alcohol, ether, ketone organic impurities, as well as moisture, metal cations, anions and particulate matter, which seriously affects the product quality. Therefore, a new ultra-clean high-purity isopropyl alcohol preparation method is needed to further reduce the alcohol, ether, ketone organic impurities, as well as metal cations, anions and particulate matter in the product. Summary of the invention

[0004] The purpose of the present invention is to overcome the technical defects of the prior art, such as poor product quality and high content of alcohol, ether, ketone organic impurities, moisture, metal cations, anions and particulate matter, and to provide a method for preparing ultra-clean high-purity isopropyl alcohol and a system thereof. The method of the present invention can obtain an ultra-clean high-purity isopropyl alcohol product with low content of alcohol, ether, ketone impurities, moisture, metal cations, anions and particulate matter.

[0005] In order to achieve the above object, the present invention provides a method for preparing ultra-clean high-purity isopropyl alcohol, which comprises:

[0006] The isopropanol raw material is subjected to a first distillation and a first adsorption, wherein the first distillation is used to remove organic light components and water, and the first adsorption is used to remove organic impurities including water, alcohol, ether and ketone, and the first adsorption is performed before or after the first distillation;

[0007] Then, a second distillation and a second adsorption are performed, wherein the second distillation is used to remove organic heavy components and most of the metal cations and anions, and the second adsorption is used to further remove the metal cations and anions; the second adsorption is performed before or after the second distillation;

[0008] After that, a third distillation is performed to further remove water, alcohol, ether and ketone organic impurities, metal cations and anions;

[0009] Then filter to obtain ultra-clean high-purity isopropyl alcohol.

[0010] Another aspect of the present invention provides a method for preparing ultra-clean high-purity isopropyl alcohol, the method comprising:

[0011] a) performing a first distillation of the isopropanol raw material to remove organic light components and water to obtain a bottom distillate 3;

[0012] b) subjecting the bottom distillate to a first adsorption to remove organic impurities including water, alcohol, ether and ketone to obtain an adsorbed product;

[0013] c) subjecting the adsorbed product to a second distillation to remove organic heavy components and most of the metal cations and anions to obtain a tower top distillate;

[0014] d) subjecting the top distillate to a second adsorption to further remove metal cations and anions to obtain an adsorbed product;

[0015] e) subjecting the adsorbed product to a third distillation to further remove water, alcohol, ether and ketone organic impurities, metal cations and anions to obtain a side distillate;

[0016] f) The side distillate is subjected to deep filtration to remove particulate matter to obtain ultra-clean high-purity isopropyl alcohol.

[0017] The method for preparing ultra-clean high-purity isopropyl alcohol provided by the present invention first removes light components and a part of water by distillation, then further removes water and light components that are difficult to remove by distillation, especially alcohol, ketone, and ether organic impurities, by an adsorption method, then removes heavy components and a large amount of metal cations and anions by distillation, and then removes the remaining metal cations and anions by adsorption, and finally removes water, alcohol, ketone, and ether organic impurities by re-distillation, and obtains an ultra-clean high-purity isopropyl alcohol product with low content of alcohol, ketone, ether organic impurities, water, metal cations, anions and particulate matter after the product passes through a filtering unit.

[0018] Another aspect of the present invention provides a system for preparing ultra-clean high-purity isopropyl alcohol, the system comprising: a first distillation unit and a first adsorption unit connected along a material flow direction; a second distillation unit and a second adsorption unit; a third distillation unit and a filtration unit;

[0019] Wherein, the first adsorption unit is before or after the first distillation unit, and the second adsorption unit is before or after the second distillation unit;

[0020] Preferably, along the material flow direction, the system comprises: a first distillation unit, a first adsorption unit, a second distillation unit, a second adsorption unit, a third distillation unit and a filtration unit which are sequentially connected in series.

[0021] The system for preparing ultra-clean high-purity isopropyl alcohol of the present invention removes organic impurities, especially alcohol, ether, ketone organic impurities, metal cations and anions, and particulate matter in isopropyl alcohol in an orderly and graded manner through an ingenious combination of a multi-stage distillation unit, a multi-stage adsorption unit, and a filtration unit, thereby effectively reducing the impurity content in the product and improving the product quality of the ultra-clean high-purity isopropyl alcohol. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic flow chart of a method for preparing ultra-clean high-purity isopropyl alcohol according to a specific embodiment of the present invention;

[0023] Among them, ① is the first distillation unit, ② is the first adsorption unit, ③ is the second distillation unit, ④ is the second adsorption unit, ⑤ is the third distillation unit, and ⑥ is the filtration unit.

[0024] Among them, 1 is the isopropanol raw material, 2 is the top distillate of the first distillation unit, 3 is the bottom distillate of the first distillation unit, 4 is the adsorption product of the first adsorption unit, 5 is the bottom distillate of the second distillation unit, 6 is the top distillate of the second distillation unit, 7 is the adsorption product of the second adsorption unit, 8 is the top distillate of the third distillation unit, 9 is the bottom distillate of the third distillation unit, 10 is the side distillate of the third distillation unit, and 11 is the ultra-clean high-purity isopropanol product. DETAILED DESCRIPTION

[0025] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0026] The present invention provides a method for preparing ultra-clean high-purity isopropyl alcohol, the method comprising:

[0027] The isopropanol raw material is subjected to a first distillation and a first adsorption, wherein the first distillation is used to remove organic light components and water, and the first adsorption is used to remove organic impurities including water, alcohol, ether and ketone, and the first adsorption is performed before or after the first distillation;

[0028] Then, a second distillation and a second adsorption are performed, wherein the second distillation is used to remove organic heavy components and most of the metal cations and anions, and the second adsorption is used to further remove the metal cations and anions; the second adsorption is performed before or after the second distillation;

[0029] After that, a third distillation is performed to further remove water, alcohol, ether and ketone organic impurities, metal cations and anions;

[0030] Then filter to obtain ultra-clean high-purity isopropyl alcohol.

[0031] In the present invention, when the second adsorption is carried out before the second distillation unit, the second distillation and the third distillation can be combined and implemented using one distillation tower.

[0032] According to a preferred embodiment of the present invention, the present invention provides a method for preparing ultra-clean high-purity isopropyl alcohol, the method comprising:

[0033] a) performing a first rectification of the isopropanol raw material 1 to remove organic light components, thereby obtaining a tower top effluent 2 and a tower bottom distillate 3;

[0034] b) the bottom distillate 3 is subjected to a first adsorption to remove organic impurities including water, alcohol, ether, and ketone to obtain an adsorbed product 4;

[0035] c) the adsorption product 4 is subjected to a second distillation to remove organic heavy components and most of the metal cations and anions, thereby obtaining a bottom effluent 5 and a top distillate 6;

[0036] d) the tower top distillate 6 is subjected to a second adsorption to further remove metal cations and anions to obtain an adsorbed product 7;

[0037] e) subjecting the adsorbed product 7 to a third distillation to further remove water, alcohol, ether, ketone organic impurities, metal cations and anions, to obtain a tower top effluent 8, a tower bottom effluent 9 and a side distillate 10;

[0038] f) The side distillate is subjected to deep filtration to remove particulate matter to obtain an ultra-clean high-purity isopropanol product 11.

[0039] The present invention has no special requirements for the feed position of the first distillation. According to a preferred embodiment of the present invention, the first distillation feed is the middle and upper part of the distillation tower. The purpose of the first distillation is to remove light components and moisture from the isopropanol raw material. In order to ensure the removal effect of light components, the feed position is preferably set at the middle and upper part of the distillation tower.

[0040] In the present invention, the purpose of the first distillation is to remove organic light components and moisture. The operating conditions are determined according to the materials. According to a preferred embodiment of the present invention, the operating pressure (absolute pressure) of the first distillation is 101.325kpa-150kpa; the reflux ratio is 2-30, and the bottom temperature is controlled to be 82.5℃-93.0℃.

[0041] According to a preferred embodiment of the present invention, the operating pressure (absolute pressure) of the first distillation is preferably 101.325 kpa-125 kpa; and the reflux ratio is preferably 8-20.

[0042] According to a preferred embodiment of the present invention, the operating pressure (absolute pressure) of the first rectification adopts 101.325kPa-150kPa micro-positive pressure rectification mode, can prevent the organic impurities outside the system from entering the system during the rectification process, can promote the boiling point difference between light constituent and isopropanol again, contribute to the removal of light constituent, wherein the operating pressure (absolute pressure) is preferably 101.325kpa-125kpa, can achieve the above purpose within the scope, and need not introduce too high pressure, increase the energy consumption of overhead condenser and tower reactor reboiler. Similarly, in order to ensure the recovery of isopropanol in the light constituent removal process, this process needs to be operated under a larger reflux ratio, but the larger reflux ratio will affect the removal effect of light constituent. Research has found that within the reflux ratio range of 2-30, good effect is arranged, wherein preferred reflux ratio is 8-20.

[0043] Considering that isopropanol and water form a minimum azeotropic system, a portion of water will be distilled out from the top of the distillation tower during the first distillation process. Therefore, in the process of removing light components from isopropanol, the first distillation also removes a portion of water, which greatly reduces the water content in the bottom product.

[0044] The present invention has no special requirements on the operating conditions of the first adsorption, as long as the organic impurities including water, alcohol, ether and ketone are removed. According to a preferred embodiment of the present invention, the first adsorption is carried out in an adsorption column, and the material is fed from the bottom of the adsorption column.

[0045] The present invention has no special requirements for the operating conditions of the first adsorption, etc., as long as it is ensured that organic impurities including water, alcohol, ether, and ketone are removed. There are no special requirements for the selection of adsorbents. According to a preferred embodiment of the present invention, the adsorption column is filled with a mixed molecular sieve containing 4A molecular sieve and 5A molecular sieve; preferably, the filling ratio of the 4A molecular sieve to the 5A molecular sieve is 1:3 to 3:1; due to the close boiling points and the presence of multiple azeotropes, it is difficult to completely remove the alcohol, ether, and ketone organic impurities in isopropanol in the first distillation process, so the product after distillation still contains a certain amount of alcohol, ether, and ketone organic impurities. For this reason, the purpose of the first adsorption is to remove alcohol, ether, and ketone organic impurities and continue to remove water. The adsorption column is an ordinary adsorption device. Since it is liquid-phase feed, it is easier to operate by feeding from the bottom of the adsorption column. Studies have found that the 4A molecular sieve has a good adsorption capacity for water in the isopropanol system, and the 5A molecular sieve has a certain adsorption capacity for water, and it also has a very good adsorption capacity for alcohol, ether, and ketone organic impurities in isopropanol. Therefore, in a preferred embodiment, a mixed molecular sieve of type 4A molecular sieve and type 5A molecular sieve is filled in the adsorption column to jointly remove water and organic impurities such as alcohol, ether and ketone in the bottom product after the first distillation; in order to ensure the removal effect of water and organic impurities such as alcohol, ether and ketone in the bottom product after the first distillation, it is necessary to set the filling ratio of type 4A molecular sieve to type 5A molecular sieve in the adsorption column. Studies have found that when the filling ratio of type 4A molecular sieve to type 5A molecular sieve is in the range of 1:3 to 3:1, there is a better removal effect of water and organic impurities such as alcohol, ether and ketone.

[0046] According to a preferred embodiment of the present invention, in order to ensure the use effect of the mixed molecular sieve, it is necessary to activate it at 250°C-500°C for 3h-5h before use to further remove organic impurities and moisture in the molecular sieve pores.

[0047] According to a preferred embodiment of the present invention, the second distillation feed is the middle and lower part of the distillation tower; the purpose of the second distillation is to remove the heavy components and most of the metal cations and anions in the product after the first adsorption. In order to ensure the removal effect of the heavy components and metal cations and anions, the feed position is preferably set in the middle and lower part of the distillation tower. After the first adsorption, a large amount of anions and cations will be enriched in the product. In the second distillation process, these ions are mostly enriched in the tower bottom, and the content of metal cations and anions in the overhead distillate will be greatly reduced.

[0048] According to a preferred embodiment of the present invention, the operating pressure (absolute pressure) of the second distillation is 101.325kpa-150kpa; the reflux ratio is 0.2-10, and the top temperature is controlled to be 82.0℃-92.5℃, wherein the operating pressure (absolute pressure) is preferably 101.325kpa-125kpa; the reflux ratio is preferably 0.5-2; the operating pressure (absolute pressure) of the second distillation adopts a 101.325kPa-150kPa micro-positive pressure distillation method, which can prevent organic impurities outside the system from entering the system during the distillation process, and can also increase the boiling point difference between isopropanol and the heavy components, which is helpful for the removal of the heavy components, wherein the operating pressure (absolute pressure) is preferably 101.325kpa-125kpa, within this range, the above-mentioned purpose can be achieved without introducing too high a pressure, which increases the energy consumption of the top condenser and the bottom reboiler. Similarly, in order to ensure the recovery rate of isopropyl alcohol in the process of removing water, heavy components, metal cations and anions, this process needs to be operated at a smaller reflux ratio, but a smaller reflux ratio will affect the removal effect of heavy components, metal cations and anions. Studies have found that preferably within the range of 0.2-10 reflux ratios, good results are achieved, wherein the preferred reflux ratio is 0.5-2.

[0049] The present invention has no special requirements for the operating conditions of the second adsorption, etc., as long as the residual metal cations and anions are removed. There are no special requirements for the selection of adsorbents. According to a preferred embodiment of the present invention, the second adsorption is carried out by an adsorption device with at least two adsorption columns in series, and the deboration resin and the mixed bed resin are respectively loaded along the material flow direction; the purpose of the second adsorption is to remove impurity elements such as boron and other residual metal cations and anions in the top distillate after the second distillation. According to the removal order, the impurity elements such as boron can be removed first, and then the other metal cations and anions can be removed to prevent the generation of new anions and cations during the boron removal process, which are eventually brought into the product.

[0050] According to a preferred embodiment of the present invention, the deboronizing resin is a chelating resin, and the mixed bed resin comprises a strongly acidic cation resin and a strongly basic anion resin; studies have found that the combined application of the above resins has a good effect in the removal of boron and other metal cations and anions, and can ensure that the boron and other metal cations and anions in the removed product meet the corresponding requirements.

[0051] According to a preferred embodiment of the present invention, the deboronized resin and mixed bed resin are replaced with the product before use, and the amount of the product used is 2-20 times the volume of the loaded resin; the deboronized resin and mixed bed resin contain a large amount of water and a small amount of organic and inorganic impurities. Before use, the resin is treated with the product to remove the water and organic and inorganic impurities in the deboronized resin and mixed bed resin, thereby avoiding affecting the product quality. Studies have found that when the amount of the product used is 2-20 times the volume of the loaded resin, the moisture and organic and inorganic impurities in the resin can be removed well.

[0052] According to a preferred embodiment of the present invention, the third distillation feed is the middle and lower part of the distillation tower; the purpose of the third distillation is to remove the metal cations and anions and alcohol, ether, ketone organic impurities remaining in the second adsorption product, the alcohol, ether, ketone organic impurities can be distilled from the top of the third distillation tower, and the water, metal cations and anions are mainly distilled from the bottom of the third distillation tower. In order to ensure the removal effect of metal cations and anions, as well as alcohol, ketone, ether organic impurities, the feed position needs to be set in the middle and lower part of the distillation tower.

[0053] In the present invention, the purpose of the third distillation is to further remove water, alcohol, ether, ketone organic impurities, metal cations and anions. The operating conditions are determined according to the materials. According to a preferred embodiment of the present invention, the operating pressure (absolute pressure) of the third distillation is 101.325kpa-150kpa; the reflux ratio is 0.2-10, and the tower top temperature is controlled to be 82.0℃-92.5℃, wherein the operating pressure (absolute pressure) is preferably 101.325kpa-125kpa; the reflux ratio is preferably 0.5-2; the operating pressure (absolute pressure) of the third distillation adopts a 101.325kPa-150kPa micro-positive pressure distillation method, which can prevent organic impurities outside the system from entering the system during the distillation process, and can also increase the boiling point difference between isopropanol and alcohol, ether, ketone organic impurities, which is conducive to the removal of light components. Within the above pressure range, it also has a good removal ability for metal cations and anions. Wherein operating pressure (absolute pressure) is preferably 101.325kpa-125kpa, can achieve the above purpose in this scope, and need not introduce too high pressure again, increase the energy consumption of overhead condenser and tower reactor reboiler.In order to ensure that the tower top can remove alcohol, ether, ketone organic impurities, the tower reactor can remove residual metal cation and anion, need to strictly control the size of reflux ratio, too large easily cause alcohol, ether, ketone removal unclean, too small easily cause isopropyl alcohol recovery rate to reduce, metal cation and anion removal effect is not good.Research finds that in the reflux ratio range of 0.2-10, there is good effect, wherein preferably 0.5-2.

[0054] According to a preferred embodiment of the present invention, the top distillate of the third distillation is returned to the feed position of the first distillation and / or the second distillation; the bottom distillate of the third distillation is returned to the feed position of the second distillation and / or the first distillation; the side distillate is extracted from the side line in the middle and upper part of the third distillation tower; the top product of the third distillation contains alcohol, ether, ketone organic impurities, which belong to light components, and this stream of material is returned to the first distillation unit and fed together with the isopropanol raw material. The bottom product of the third distillation contains a small amount of metal cations and anions, which can be returned to the second distillation unit and / or the first distillation unit for removal. A side line is provided in the middle and upper part of the third distillation, and an ultra-clean high-purity isopropanol product can be obtained at this position.

[0055] According to a preferred embodiment of the present invention, the filtration is carried out in a filtration device, the filtration device is multi-stage series, preferably 4-10 stages, preferably, the cut-off particle size specifications of the 4-stage filter are 0.5μm, 0.2μm, 0.1μm and 50nm, or 0.5μm, 0.1μm, 50nm, 30nm; the filtration device is a common filtration device, containing pipes, valves, filter housings and filters and other components, the filter element of the filter is, for example, a filter membrane made of materials such as PFA, PTFE, PE, etc., installed in the filter housing. Studies have found that in the multi-stage series filtration device, at least one filter element of the filter uses an ion exchange membrane, which can further reduce the ion content in the product, for example, a five-stage series is used, the filter element of the first filter uses an ion exchange membrane (model: MGSX110OTCPUHD), and the cut-off particle size specifications of the remaining 4 filters are set to 0.5μm, 0.1μm, 50nm, 30nm.

[0056] According to a preferred embodiment of the present invention, in the isopropanol raw material, the isopropanol purity is ≥98.0%, and / or the water content is ≤2000ppm, and / or the alcohol impurity content is ≤1000ppm, and / or the ether impurity content is ≤1000ppm, and / or the ketone impurity content is ≤1000ppm. Wherein the alcohol impurities refer to methanol, ethanol, n-propanol, n-butanol, n-pentanol, isobutanol, tert-butanol, 2-hexanol, etc., the ether impurities refer to ether, isopropyl ether, etc., and the ketone impurities refer to acetone, butanone, pentanone, etc. The raw materials within the above range can be used to prepare ultra-clean high-purity isopropanol through this process, but it is not limited to isopropanol raw materials beyond this range that cannot be used to prepare ultra-clean high-purity isopropanol through this invention.

[0057] According to a preferred embodiment of the present invention, in the isopropanol raw material, the isopropanol purity is ≥98.0%, the water content is ≤2000ppm, the alcohol impurity content is ≤1000ppm, the ether impurity content is ≤1000ppm, and the ketone impurity content is ≤1000ppm.

[0058] In the present invention, the isopropanol raw material generally contains metal ions and anions, which are well known to those skilled in the art and will not be described in detail herein.

[0059] According to a preferred embodiment of the method of the present invention, the purity of ultra-clean high-purity isopropanol is ≥99.999%, and / or the water content is ≤30ppm, and / or the alcohol impurity content is ≤10ppm, and / or the ether impurity content is ≤10ppm, and / or the ketone impurity content is ≤10ppm, and / or the single metal cation content is ≤10ppt, and / or the single anion content is ≤5ppb, and / or the particles (particle size ≥50nm) are ≤100 / ml.

[0060] Another aspect of the present invention provides a system for preparing ultra-clean high-purity isopropyl alcohol, the system comprising:

[0061] Along the material flow direction, the first distillation unit ①, the first adsorption unit ②; the second distillation unit ③, the second adsorption unit ④; the third distillation unit ⑤ and the filtration unit ⑥ are connected;

[0062] The first adsorption unit is before or after the first distillation unit, and the second adsorption unit is before or after the second distillation unit.

[0063] According to a preferred embodiment of the present invention, the system comprises: a first distillation unit ①, a first adsorption unit ②, a second distillation unit ③, a second adsorption unit ④, a third distillation unit ⑤ and a filtration unit ⑥ which are sequentially connected in series along the material flow direction.

[0064] According to a preferred embodiment of the present invention, in the system for preparing ultra-clean high-purity isopropyl alcohol, the first distillation unit includes a distillation tower.

[0065] According to a preferred embodiment of the present invention, in the system for preparing ultra-clean high-purity isopropyl alcohol, the first adsorption unit is an adsorption device comprising an adsorption column, and the adsorption column is filled with a mixed molecular sieve comprising a 4A molecular sieve and a 5A molecular sieve; preferably, the filling ratio of the 4A molecular sieve to the 5A molecular sieve is 1:3-3:1.

[0066] According to a preferred embodiment of the present invention, in the system for preparing ultra-clean high-purity isopropyl alcohol, the second distillation unit comprises a distillation tower.

[0067] According to a preferred embodiment of the present invention, in the system for preparing ultra-clean high-purity isopropyl alcohol, the second adsorption unit includes an adsorption device having at least two adsorption columns connected in series, and a deboronating resin and a mixed bed resin are respectively loaded along the material flow direction, the deboronating resin is a chelating resin, and the mixed bed resin comprises a strongly acidic cation exchange resin and a strongly basic anion exchange resin.

[0068] According to a preferred embodiment of the present invention, in the system for preparing ultra-clean high-purity isopropyl alcohol, the third distillation unit includes a distillation tower, and preferably a side line outlet is provided in the middle and upper part.

[0069] According to a preferred embodiment of the present invention, in the system for preparing ultra-clean high-purity isopropyl alcohol, the filtration unit includes multiple stages of filtration devices connected in series.

[0070] According to a preferred embodiment of the present invention, the bottom outlet of the third distillation unit is connected to the feed inlet of the second distillation unit and / or the first distillation unit.

[0071] According to a preferred embodiment of the present invention, the top outlet of the third distillation unit is connected to the feed inlet of the first distillation unit and / or the second distillation unit.

[0072] The system for preparing high-purity isopropyl alcohol of the present invention removes organic impurities, especially alcohol, ether, ketone organic impurities, water, metal cations and anions, and particulate matter in isopropyl alcohol in an orderly and graded manner through an ingenious combination of a distillation unit, an adsorption unit, and a filtration unit, thereby effectively reducing the impurity content in the product and improving the product quality of ultra-clean high-purity isopropyl alcohol.

[0073] The present invention is further described below through specific examples. The scope of the present invention is not limited to the scope covered by the examples. The product purity, ketones, ethers, and ketone organic impurities in the examples are detected by gas chromatography (Agilent GC7890), the water content is determined by Karl Fischer titrator (Mettler V30S), the metal ions are determined by ICP-MS / MS (Agilent 8900), the anions are determined by ion chromatography (Thermo Fisher ICS-6000+), and the particle count is determined by a liquid particle counter (RIONKS-19F).

[0074] Example 1

[0075] There is a batch of isopropanol raw materials, and the purity of isopropanol is 99.9%, the water content is 480ppm, the alcohol impurities (mainly ethanol) are 270ppm, the ether impurities (mainly isopropyl ether) are 180ppm, the ketone impurities (mainly acetone) are 340ppm, and the other organic impurities are 210ppm. It is injected from the middle and upper part of the first distillation unit. The operating pressure of the first distillation unit is 120kPa, the reflux ratio is 10, and the operating temperature of the tower bottom is controlled to be 87℃. The obtained tower bottom distillate enters from the bottom of the first adsorption unit. The first adsorption unit is filled with a mixed molecular sieve of 4A type and 5A type molecular sieve. The volume ratio of 4A type and 5A type molecular sieve is 1:1 (the mixed molecular sieve is activated at 350℃ for 4h before use). The product after adsorption treatment by the first adsorption unit enters the second distillation unit from the middle and lower part. The operating pressure of the second distillation unit is 120kPa, the reflux ratio is 1, and the operating temperature of the tower top is controlled to be 86.5℃. The obtained top distillate of the second distillation unit enters from the top of the second adsorption unit, and is sequentially treated in series with adsorption columns filled with deboronating resin Ambertec UP7530 and mixed bed resin AMBERJET UP6040 (composed of strong acidic cation resin and strong basic anion resin) (before use, the resin is replaced with 10 times its volume of product, and the amount of product used is 10 times the volume of the loaded resin). The adsorbed product obtained after the second adsorption treatment enters the third distillation unit from the middle and lower part. The operating pressure of the third distillation unit is 120kPa, the reflux ratio is 1, and the top operating temperature is controlled to be 86.5°C. The product obtained from the side line enters the filtration unit. The filtration unit uses a 4-stage filter, which is connected in series in sequence. The filter retention particle size specifications are set to 0.5μm, 0.2μm, 0.1μm, and 50nm, and finally ultra-clean high-purity isopropanol is obtained.

[0076] The product was analyzed according to the analytical method specified in the standard SEMI C41-0618. The purity of the obtained ultra-clean high-purity isopropyl alcohol was 99.9996%, the alcohol and ether organic impurities were undetectable, the acetone content was 4ppm, the water content was 30ppm, the single metal cation content was ≤8ppt, the single anion content was ≤3ppb, the particles (≥50nm) were 23 / ml, the main cation content (ppt) in the product was shown in Table 1, and the main anion content (ppb) in the product was shown in Table 2.

[0077] Table 1 Main cation content in products (ppt)

[0078]

[0079]

[0080] Table 2 Main anion content in the product (ppb)

[0081] Anions unit After detachment <![CDATA[F - ]]> ppb 1 <![CDATA[Cl - ]]> ppb 2 <![CDATA[Br - ]]> ppb 1 <![CDATA[NO2 - ]]> ppb 3 <![CDATA[NO3 - ]]> ppb 2 <![CDATA[PO4 3- ]]> ppb 1 <![CDATA[SO4 2- ]]> ppb 1

[0082] Example 2

[0083] The method of Example 1 was followed and the same isopropanol raw material was used. The difference was that the filtration unit used 4-stage filters, which were connected in series in sequence. The filter retention particle size specifications were set to 0.5 μm, 0.1 μm, 50 nm, and 30 nm, and ultra-clean high-purity isopropanol was finally obtained.

[0084] The product was analyzed according to the analytical method specified in the standard SEMI C41-0618. The purity of the obtained ultra-clean high-purity isopropyl alcohol was 99.9997%, the content of alcohol and ether organic impurities was undetectable, the acetone content was 3ppm, the water content was 27ppm, the single metal cation was ≤9ppt, the single anion was ≤4ppb, the particles (≥50nm) were 5 / ml, and the particles (>30nm) were 20 / ml.

[0085] Example 3

[0086] The method of Example 1 was followed, using the same isopropanol raw material, except that the filtration unit used a 5-stage filter, which was connected in series in sequence, the filter element of the first-stage filter used an ion exchange membrane (model: MGSX110OTCPUHD), and the retention particle size specifications of the remaining 4-stage filters were set to 0.5 μm, 0.1 μm, 50 nm, and 30 nm, and ultra-clean high-purity isopropanol was finally obtained.

[0087] The product was analyzed according to the analytical method specified in the standard SEMI C41-0618. The purity of the obtained ultra-clean high-purity isopropyl alcohol was 99.9998%, the content of alcohol and ether organic impurities was undetectable, the acetone content was 2ppm, the water content was 25ppm, the single metal cation was ≤5ppt, the single anion was ≤3ppb, the particles (≥50nm) were 3 / ml, and the particles (≥30nm) were 18 / ml.

[0088] Comparative Example 1

[0089] According to the method of Example 1, the same isopropanol raw material is used, except that there is no first adsorption unit, and ultra-clean high-purity isopropanol is finally obtained.

[0090] The product was analyzed according to the analytical method specified in the standard SEMI C41-0618. The purity of the obtained ultra-clean high-purity isopropyl alcohol was 99.9965%, the ethanol content was 20ppm, the isopropyl ether content was 5ppm, the acetone content was 10ppm, the water content was 80ppm, the single metal cation was ≤9ppt, the single anion was ≤4ppb, and the particle size (≥50nm) was 41 / ml.

[0091] Comparative Example 2

[0092] The method of Example 1 is followed, using the same isopropanol raw material, except that there is no third distillation unit, and ultra-clean high-purity isopropanol is finally obtained.

[0093] The product was analyzed according to the analytical method specified in the standard SEMI C41-0618. The purity of the obtained ultra-clean high-purity isopropyl alcohol was 99.992%, the content of alcohol organic impurities was undetectable, the content of isopropyl ether was 50ppm, the content of acetone was 30ppm, the content of water was 160ppm, the single metal cation was ≤10ppt, the single anion was ≤5ppb, and the particle size (≥50nm) was 52 / ml.

[0094] Comparative Example 3

[0095] The method of Example 1 is followed by using the same isopropanol raw material, except that the second adsorption unit is placed after the third distillation unit, and ultra-clean high-purity isopropanol is finally obtained.

[0096] The product was analyzed according to the analytical method specified in the standard SEMI C41-0618. The purity of the obtained ultra-clean high-purity isopropyl alcohol was 99.995%, the content of alcohol organic impurities was undetectable, the content of isopropyl ether was 30ppm, the content of acetone was 20ppm, the content of water was 130ppm, the single metal cation was ≤8ppt, the single anion was ≤5ppb, and the particle size (≥50nm) was 38 / ml.

[0097] Example 4

[0098] The method of Example 1 is followed by using the same isopropanol raw material, except that the first adsorption unit is placed before the first distillation unit, and ultra-clean high-purity isopropanol is finally obtained.

[0099] The product was analyzed according to the analytical method specified in the standard SEMI C41-0618. The purity of the obtained ultra-clean high-purity isopropyl alcohol was 99.9995%, the content of alcohol and ether organic impurities was undetectable, the acetone content was 5ppm, the water content was 33ppm, the single metal cation was ≤10ppt, the single anion was ≤4ppb, and the particle size (≥50nm) was 25 / ml.

[0100] Example 5

[0101] The method of Example 1 is followed by using the same isopropanol raw material, except that the second adsorption unit is placed before the second distillation unit, and ultra-clean high-purity isopropanol is finally obtained.

[0102] The product was analyzed according to the analytical method specified in the standard SEMI C41-0618. The purity of the obtained ultra-clean high-purity isopropyl alcohol was 99.9993%, the content of alcohol and ether organic impurities was undetectable, the acetone content was 7ppm, the water content was 42ppm, the single metal cation was ≤9ppt, the single anion was ≤5ppb, and the particle size (≥50nm) was 25 / ml.

[0103] Example 6

[0104] The method of Example 1 is followed, except that the purity of the isopropanol raw material is 99.85%, the water content is 1100 ppm, the alcohol impurities are 530 ppm, the ether impurities are 220 ppm, the ketone impurities are 430 ppm, and the other organic impurities are 320 ppm, and ultra-clean high-purity isopropanol is finally obtained.

[0105] The product was analyzed according to the analytical method specified in the standard SEMI C41-0618. The purity of the obtained ultra-clean high-purity isopropyl alcohol was 99.9994%, the content of alcohol and ether organic impurities was undetectable, the acetone content was 6ppm, the water content was 34ppm, the single metal cation was ≤9ppt, the single anion was ≤3ppb, and the particle size (≥50nm) was 32 / ml.

Claims

1. A method for preparing ultra-clean high-purity isopropyl alcohol, It is characterized in that The method includes: The isopropanol raw material is subjected to a first distillation and a first adsorption, wherein the first distillation is used to remove organic light components and water, and the first adsorption is used to remove organic impurities including water, alcohol, ether and ketone, and the first adsorption is performed before or after the first distillation; Then, a second distillation and a second adsorption are performed, wherein the second distillation is used to remove organic heavy components and most of the metal cations and anions, and the second adsorption is used to further remove the metal cations and anions; the second adsorption is performed before or after the second distillation; After that, a third distillation is performed to further remove water, organic impurities such as alcohols, ethers and ketones, metal cations and anions; Then filter to obtain ultra-clean high-purity isopropyl alcohol.

2. A method for preparing ultra-clean high-purity isopropyl alcohol, It is characterized in that The method includes: a) performing a first rectification of the isopropanol raw material to remove organic light components and water to obtain a bottom distillate; b) subjecting the bottom distillate to a first adsorption to remove organic impurities including water, alcohol, ether and ketone to obtain an adsorbed product; c) subjecting the adsorbed product to a second distillation to remove organic heavy components and most of the metal cations and anions to obtain a tower top distillate; d) subjecting the top distillate to a second adsorption to further remove metal cations and anions to obtain an adsorbed product; e) subjecting the adsorbed product to a third distillation to further remove water, alcohol, ether and ketone organic impurities, metal cations and anions to obtain a side distillate; f) The side distillate is subjected to deep filtration to remove particulate matter, metal cations and anions to obtain ultra-clean high-purity isopropyl alcohol.

3. The method according to claim 1 or 2, in, The first distillation feed is the middle and upper part of the distillation tower: the operating pressure (absolute pressure) of the distillation tower is 101.325kpa-150kpa; the reflux ratio is 2-30, and the bottom temperature of the tower is controlled to be 82.5℃-93.0℃; wherein, the operating pressure (absolute pressure) is preferably 101.325kpa-125kpa; the reflux ratio is preferably 8-20.

4. The method according to claim 1 or 2, in, The first adsorption is carried out in an adsorption column, and the material is fed from the bottom of the adsorption column. The adsorption column is filled with a mixed molecular sieve containing type 4A molecular sieve and type 5A molecular sieve; preferably, the filling ratio of type 4A molecular sieve to type 5A molecular sieve is 1:3 to 3:1; preferably, the mixed molecular sieve needs to be activated at 250°C-500°C for 3h-5h before use.

5. The method according to claim 1 or 2, in, The second distillation feed is the middle and lower part of the distillation tower: the operating pressure (absolute pressure) of the distillation tower is 101.325kpa-150kpa; the reflux ratio is 0.2-10, and the top temperature is controlled to be 82.0℃-92.5℃; wherein, the operating pressure (absolute pressure) is preferably 101.325kpa-125kpa; the reflux ratio is preferably 0.5-2.

6. The method according to claim 1 or 2, in, The second adsorption is carried out by using an adsorption device having at least two adsorption columns connected in series, and a deboration resin and a mixed bed resin are respectively loaded along the material flow direction, wherein the deboration resin is a chelating resin, and the mixed bed resin comprises a strongly acidic cationic resin and a strongly basic anionic resin; Preferably, the deboronized resin and mixed bed resin are subjected to a replacement treatment with a product before use.

7. The method according to claim 1 or 2, in, The third distillation feed is the middle and lower part of the distillation tower: the operating pressure (absolute pressure) of the distillation tower is 101.325kpa-150kpa; the reflux ratio is 0.2-10, and the top temperature is controlled to be 82.0℃-92.5℃; wherein, the operating pressure (absolute pressure) is preferably 101.325kpa-125kpa; the reflux ratio is preferably 0.5-2.

8. The method according to claim 1 or 7, in, The overhead product of the third distillation is returned to the feed position of the first distillation and / or the second distillation; and / or The bottom distillate of the third distillation is returned to the feed position of the second distillation and / or the first distillation; and / or A side distillate is taken out from the middle and upper part of the distillation tower of the third distillation.

9. The method according to claim 1 or 2, in, The filtration is carried out in a filtration device, which is a multi-stage cascade, preferably 4-10 stages; Preferably, in the multi-stage filtration device connected in series, the filter element of at least one stage of the filter adopts an ion exchange membrane.

10. The method according to any one of claims 1 to 9, in, In the isopropanol raw material, the isopropanol purity is ≥98.0%, the water content is ≤2000ppm, the alcohol impurity content is ≤1000ppm, the ether impurity content is ≤1000ppm, and the ketone impurity content is ≤1000ppm.

11. The method according to any one of claims 1 to 10, in, Ultra-clean high-purity isopropanol purity ≥ 99.999%, and / or water content ≤ 30ppm, and / or alcohol impurity content ≤ 10ppm, and / or ether impurity content ≤ 10ppm, and / or ketone impurity content ≤ 10ppm, and / or single metal cation content ≤ 10ppt, and / or single anion content ≤ 5ppb, and / or particles (particle size ≥ 50nm) ≤ 100 / ml.

12. A system for preparing ultra-clean high-purity isopropyl alcohol, It is characterized in that The system includes: Along the material flow direction, the first distillation unit and the first adsorption unit are connected; the second distillation unit and the second adsorption unit; the third distillation unit and the filtration unit; Wherein, the first adsorption unit is before or after the first distillation unit, and the second adsorption unit is before or after the second distillation unit; Preferably, along the material flow direction, the system comprises: a first distillation unit, a first adsorption unit, a second distillation unit, a second adsorption unit, a third distillation unit and a filtration unit which are sequentially connected in series.

13. The system according to claim 12, in, The first distillation unit comprises a distillation column; and / or The first adsorption unit is an adsorption device comprising an adsorption column, wherein the adsorption column is filled with a mixed molecular sieve comprising a 4A molecular sieve and a 5A molecular sieve; preferably, the filling ratio of the 4A molecular sieve to the 5A molecular sieve is 1:3-3:1; and / or The second distillation unit comprises a distillation column; and / or The second adsorption unit comprises an adsorption device having at least two adsorption columns connected in series, and the deboration resin and the mixed bed resin are respectively loaded along the material flow direction, wherein the deboration resin is a chelating resin, and the mixed bed resin comprises a strongly acidic cationic resin and a strongly basic anionic resin; and / or The third distillation unit comprises a distillation tower, preferably with a side line outlet in the middle and upper part; and / or The filter unit includes at least multiple stages of filter devices connected in series; Preferably, The bottom outlet of the third distillation unit is connected to the feed inlet of the second distillation unit / or the first distillation unit; and / or The tower top outlet of the third distillation unit is communicated with the feed inlet of the first distillation unit and / or the second distillation unit.

Images