Method for adsorbing and removing isopropyl ether and / or acetone in isopropanol

Abstract

The invention belongs to the technical field of fine chemical engineering, and relates to a method for adsorbing and removing isopropyl ether and / or acetone in isopropanol, which comprises the step of contacting MAF-6 with an isopropanol solution containing isopropyl ether and / or acetone. Compared with the prior art, the method has the advantages that by utilizing the characteristic that the adsorption selectivity of MAF-6 to isopropyl ether and acetone is far greater than that of isopropyl alcohol, MAF-6 is adopted as an adsorbent in an industrial-grade isopropyl alcohol raw material with relatively high purity, so that clear separation and efficient trapping of isopropyl alcohol, isopropyl ether and acetone impurities are realized, and the purpose of refining isopropyl alcohol is achieved. The isopropyl ether in the isopropyl alcohol treated by the adsorption separation method provided by the invention can be removed to be less than 1ppm, and the acetone can be reduced to be less than 2ppm, so that the purity requirement of high-grade electronic-grade isopropyl alcohol is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of fine chemical industry, and relates to a method for adsorptive removal of isopropyl ether and / or acetone from isopropanol. Background Art

[0002] Isopropanol, also known as 2-propanol, is an isomer of n-propanol. It is a colorless transparent liquid with a mixed odor of ethanol and acetone. As an important basic raw material and organic solvent, isopropanol plays a very important role in industrial production. In the pharmaceutical field, isopropanol is an important raw material for pharmaceutical production, mainly used for the production of drugs such as pindolol and diisopropylamine dichloroacetate; in the synthesis of chemicals, isopropanol is an intermediate for the production of acetone, cosmetics and other basic chemical pesticides; as a solvent, isopropanol is mainly used as a solvent in printing inks and silicon wafer production, and is also used as a cleaner in the field of electronic soldering. In addition, with the continuous breakthrough of advanced process nodes of integrated circuits, the demand for high-grade electronic-grade isopropanol has increased rapidly, and more and more stringent requirements have been put forward for the content of organic impurities in it. Industrial-grade isopropanol is difficult to meet the requirements.

[0003] The main production processes of isopropanol include the indirect hydration method of propylene, the direct hydration method of propylene (including gas-phase direct hydration method, liquid-phase direct hydration method and gas-liquid phase mixed hydration method), and the acetone hydrogenation method, etc. At present, the main production process of isopropanol at home and abroad is the direct hydration method of propylene. Under the action of a catalyst, propylene directly undergoes a hydration reaction with water to prepare isopropanol. This method makes up for the disadvantages of low efficiency and complex process of the indirect hydration method, and has many advantages such as high efficiency, low consumption and short process flow. It is the main development direction of the current propylene hydration method for producing isopropanol. However, the isopropanol synthesized by this method often contains trace amounts of by-products such as isopropyl ether and acetone. On the one hand, azeotropes are formed among isopropanol, isopropyl ether and acetone, and it is very difficult to achieve clear separation by ordinary distillation methods; on the other hand, it is very difficult to selectively adsorb and remove trace impurities such as non-polar or weakly polar isopropyl ether and acetone from a strongly polar isopropanol solution, which seriously restricts the application of isopropanol in high-precision and advanced technology fields such as integrated circuits and the commercial value of isopropanol products.

[0004] The prior art CN 115806472 A discloses a method for preparing electronic-grade isopropanol and a system for preparing electronic-grade isopropanol. Electronic-grade isopropanol is prepared by processes such as removing light and heavy components, dehydrating, and removing metal ions in sequence, and the purity of isopropanol can be increased from 99.8% to 99.95%.

[0005] The literature "Research on the Separation of Acetone-Isopropanol-Water Mixture by Extractive Distillation Combined with Distillation" (Cao Xiaoyan, master's thesis, Nanjing Normal University) proposed a method of combining extractive distillation and distillation to separate the mixture of acetone, isopropanol and water, and the purity of isopropanol is 93.5%.

[0006] The literature "Vapour–liquid equilibrium and extractive distillation for separation of azeotrope isopropyl alcohol and diisopropyl ether" (The Journal of Chemical Thermodynamics, 2019, Vol. 131, pp. 294 - 302) proposed a process for separating isopropyl alcohol and diisopropyl ether by extractive distillation. Through this process, isopropyl alcohol with a purity of 99.7% can be obtained.

[0007] At present, although many studies have reported that the production of electronic - grade isopropyl alcohol can be achieved by adopting a series of process flows such as distillation and membrane separation, and the purity of isopropyl alcohol products can reach more than 99.9%, these studies mainly focus on the removal of water, solid particles, and anions and cations in industrial - grade isopropyl alcohol, and no effective separation scheme has been proposed for isopropyl ether and acetone, which are difficult to be clearly separated by ordinary distillation. As a result, the purity of isopropyl alcohol products is far from meeting the requirements of higher grades. For the separation of isopropyl ether and acetone in isopropyl alcohol, most of the existing studies adopt the extractive distillation process to achieve the rough separation of the isopropyl ether / isopropyl alcohol system and the acetone / isopropyl alcohol system, but there are no relevant reports on the simultaneous deep removal of trace isopropyl ether and acetone impurities in isopropyl alcohol. At the same time, the extractive distillation process also has defects such as high energy consumption and the possible introduction of extractant impurities that cannot be completely separated into the product.

[0008] Therefore, there is an urgent need for a process method for removing isopropyl ether and acetone in isopropyl alcohol to fundamentally solve the problem of isopropyl alcohol purity and effectively expand its application in high - tech fields such as integrated circuits. Summary of the Invention

[0009] The object of the present invention is to provide a method for adsorptive removal of isopropyl ether and / or acetone in isopropyl alcohol, which is used to solve the problem that in the existing isopropyl alcohol materials, especially in the crude products of industrial - grade isopropyl alcohol prepared by direct hydration of propylene, it is difficult to deeply remove trace isopropyl ether and acetone, resulting in the inability to be used in high - end applications. The present invention utilizes the characteristic that the adsorption selectivity of MAF - 6 for isopropyl ether and acetone is much greater than that for isopropyl alcohol. In industrial - grade isopropyl alcohol raw materials with relatively high purity, MAF - 6 is used as an adsorbent to achieve the clear separation and efficient capture of isopropyl alcohol and trace isopropyl ether and acetone impurities, so as to achieve the purpose of isopropyl alcohol refining. After being treated by the adsorption separation method provided by the present invention, the isopropyl ether in isopropyl alcohol can be removed to less than 1 ppm, and the acetone can be reduced to less than 2 ppm, meeting the purity requirements of high - grade electronic - grade isopropyl alcohol, effectively expanding its application in high - tech fields such as integrated circuits, and enhancing the commercial value of isopropyl alcohol products.

[0010] The object of the present invention can be achieved by the following technical solutions:

[0011] The present invention provides a method for adsorptive removal of isopropyl ether and / or acetone in isopropanol, comprising: contacting MAF-6 with an isopropanol solution containing isopropyl ether and / or acetone.

[0012] The adsorption selectivity of the MAF-6 for isopropyl ether and acetone is much greater than that for isopropanol, and selective adsorption and removal of trace isopropyl ether and acetone in isopropanol can be achieved. Specifically, the adsorption energy of the adsorption material for isopropyl ether is about 10-200 kJ / mol, preferably 20-100 kJ / mol, more preferably 40-50 kJ / mol; the adsorption energy of the adsorption material for acetone is about 10-200 kJ / mol, preferably 20-100 kJ / mol, more preferably 50-60 kJ / mol; the adsorption energy of the adsorption material for isopropanol is about 10-100 kJ / mol, preferably 10-50 kJ / mol, more preferably 20-40 kJ / mol.

[0013] In some specific embodiments, a composite material having one or more structures of molecular sieves, metal-organic framework materials, covalent organic framework materials or metal oxides is used as the adsorption material for isopropyl ether and / or acetone, and an imidazole-based metal-organic framework material is preferred.

[0014] In some specific embodiments, the adsorption material has one or more of the following characteristics:

[0015] The material has rich pores, including a combination of micropores, mesopores and macropores;

[0016] The average pore diameter of the micropores of the material is 0.1-2 nm, preferably 0.5-2 nm, more preferably 0.5-1 nm;

[0017] The average pore diameter of the mesopores of the material is 2-50 nm, preferably 2-20 nm, more preferably 2-10 nm;

[0018] The average pore diameter of the material is 0.1-50 nm, preferably 0.1-20 nm, more preferably 0.5-10 nm;

[0019] The specific surface area of the material is 100-2000 m 2 / g, preferably 100-1500 m 2 / g, more preferably 500-1500 m 2 / g;

[0020] The crystal size of the material is 0.1-100 μm, preferably 0.1-10 μm, more preferably 0.1-5 μm.

[0021] In some specific embodiments, the method for contacting the MAF-6 with the isopropanol solution is selected from one of a liquid-phase dynamic adsorption method, a gas-phase dynamic adsorption method, a liquid-phase static adsorption method, or a gas-phase static adsorption method.

[0022] The liquid-phase dynamic adsorption method includes: flowing the isopropanol solution through an adsorbent bed filled with MAF-6.

[0023] The gas-phase dynamic adsorption method includes: vaporizing the isopropanol solution in advance and flowing it through an adsorbent bed filled with MAF-6.

[0024] The liquid-phase static adsorption method includes: adding MAF-6 to the isopropanol solution.

[0025] The gas-phase static adsorption method includes: placing MAF-6 in the vapor environment of the isopropanol solution.

[0026] In some preferred embodiments, the method for contacting the MAF-6 with the isopropanol solution adopts a liquid-phase dynamic adsorption method or a gas-phase dynamic adsorption method.

[0027] In some specific embodiments, the adsorption temperature is 25-120 °C, and the feed space velocity of the isopropanol solution is 0.1-5 h -1 .

[0028] In some specific embodiments, the adsorber used is selected from one of a fixed-bed adsorber, a moving-bed adsorber, or a fluidized-bed adsorber. Preferably, the adsorber used is a fixed-bed adsorber or a moving-bed adsorber.

[0029] In some specific embodiments, in the isopropanol solution, the isopropyl ether content is not higher than 2000 ppm. That is, the present invention can be used for highly selective adsorption of isopropyl ether with a content of less than 2000 ppm in the isopropanol solution. Preferably, it can be used for highly selective adsorption of isopropyl ether with a content of less than 500 ppm. More preferably, it can be used for highly selective adsorption of isopropyl ether with a content of less than 200 ppm.

[0030] In some specific embodiments, in the isopropanol solution, the acetone content is not higher than 2000 ppm. That is, the present invention can be used for highly selective adsorption of acetone with a content of less than 2000 ppm in the isopropanol solution. Preferably, it can be used for highly selective adsorption of acetone with a content of less than 500 ppm. More preferably, it can be used for highly selective adsorption of acetone with a content of less than 200 ppm.

[0031] In some specific embodiments, the preparation method of the MAF-6 includes the following steps:

[0032] Mix 2-ethylimidazole, cyclohexane, and an alcohol solvent to obtain Reaction Solution 1; mix zinc oxide, water, and ammonia water to obtain Reaction Solution 2.

[0033] Stir and react Reaction Solution 1 and Reaction Solution 2, and then purify to obtain the product.

[0034] In some specific embodiments, the mass ratio of 2-ethylimidazole, cyclohexane, alcohol, zinc oxide, water, and ammonia water is (4 - 8):(1 - 3):250:(2 - 4):(48 - 52):(180 - 220).

[0035] In some specific embodiments, during the stirring reaction, the reaction temperature is room temperature and the reaction time is 1.5 - 2 h.

[0036] In some specific embodiments, it further includes directionally regulating the nano - micro structure and surface properties of MAF - 6 or other adsorption materials, including:

[0037] (1) Ligand modification, modifying organic ligands through chemical reactions to achieve fine modification of the material;

[0038] (2) Hybridization of multiple ligands or multiple metal ions, forming hybrid materials through coordination self - assembly of two or more ligands or metal ions. Such materials may achieve performance beyond that of single adsorption materials and have broad application prospects;

[0039] (3) Adding a template agent to control the crystal form and crystal phase of the synthesized material.

[0040] According to the requirements in the fields of chemistry, chemical engineering, energy, environmental protection, biology, medicine, electronics, machinery, etc., couple high - resolution identification adsorption materials with specific functions in some necessary situations, so as to efficiently capture trace impurities in other systems.

[0041] In some specific embodiments, this method further includes desorbing and regenerating MAF - 6.

[0042] In some specific embodiments, the desorbing gas used is selected from one or more of air, nitrogen, helium, argon, hydrogen, or carbon dioxide; preferably one or more of nitrogen, helium, and carbon dioxide.

[0043] In some specific embodiments, the desorption temperature is 25 - 60 °C and the desorption space velocity is 1 - 10 h -1 .

[0044] The inventor of the present invention, through extensive and in-depth research, unexpectedly discovered for the first time a method for adsorptive removal of trace impurities to produce electronic-grade isopropanol. Compared with the production processes of electronic-grade isopropanol reported in other studies, the adsorption separation process of the present invention can deeply remove isopropyl ether and acetone, which are difficult to be clearly separated from isopropanol by ordinary distillation, thus greatly improving the purity of the electronic-grade isopropanol product. Compared with the separation processes of the isopropyl ether / isopropanol system and the acetone / isopropanol system (mainly extractive distillation processes), the adsorption separation process of the present invention can not only effectively adsorb and remove trace isopropyl ether and acetone impurities in isopropanol at the same time, but also effectively solve the problems of high energy consumption in the existing extractive distillation separation process and the possible introduction of extractant impurities that cannot be completely separated into the product. In addition, based on the characteristics of the separation system, the present invention proposes the selection basis of the adsorbent material and the strategy of targeted and purposeful directional modification of the adsorbent material to meet specific separation requirements. Through the adsorption separation method proposed by the present invention and coupling with high-resolution identification functional adsorbent materials, an efficient capture and separation process for trace impurities in other necessary occasions can be designed, which greatly broadens the application of adsorption separation in solvent purification, impurity removal and other aspects.

[0045] Compared with the prior art, the present invention has the following characteristics:

[0046] Highly selective removal of isopropyl ether and acetone impurities: The present invention uses MAF-6 as an adsorbent. When the isopropanol stream containing trace isopropyl ether and acetone impurities contacts the above adsorbent, due to the high-resolution identification function of MAF-6, it is more inclined to adsorb the isopropyl ether and acetone therein, so as to efficiently remove the isopropyl ether and acetone impurities in the isopropanol solution and realize the purification of isopropanol. Experiments show that the isopropyl ether in the purified isopropanol obtained by the adsorption separation method can be removed to less than 1 ppm, and the acetone can be reduced to less than 2 ppm. It effectively solves the problem of difficult high-efficiency removal of trace organic impurities in the current production process of electronic-grade ultra-pure isopropanol, and at the same time effectively solves the problems of huge energy consumption in the extractive distillation separation process, easy introduction of other impurities and inability to achieve simultaneous high-efficiency deep removal of trace isopropyl ether and acetone impurities in isopropanol.

[0047] Renewable and reusable: The present invention can realize the efficient desorption of isopropyl ether and acetone in MAF-6 and the regeneration of the adsorbent by purging with gases such as air, carbon dioxide, and nitrogen. Experiments show that the adsorbent after 3 times of desorption and regeneration still maintains the removal rate of isopropyl ether higher than 90% and the removal rate of acetone higher than 60%.

[0048] Wide range of product uses: The purified electronic-grade isopropanol obtained by the adsorption separation of the present invention can be used not only as an important basic chemical raw material and organic solvent, but also as a high-grade chip surface cleaning solvent.

[0049] Simple process and wide application: The adsorption separation process of the present invention is simple, with high separation efficiency, high product recovery rate, and is easy to operate industrially, greatly broadening the application of adsorption separation in high-efficiency and deep separation processes such as solvent purification and impurity removal.

[0050] In addition to being able to deeply remove trace organic impurities such as isopropyl ether and acetone in electronic-grade isopropyl alcohol, it can also be coupled with high-resolution identification adsorption materials with specific functions, so as to efficiently capture trace impurities in other systems, such as the adsorption and removal of trace benzene and other organic substances in water. Description of the drawings

[0051] Figure 1 It is the concentration change curve of isopropyl ether and acetone during the selective adsorption of isopropyl ether and acetone from isopropyl alcohol by MAF-6 in Example 3.

[0052] Figure 2 It is the comparison chart of the regeneration and recycling effect of MAF-6 in Example 4. Detailed implementation manners

[0053] The present invention will be described in detail below with reference to the drawings and specific embodiments.

[0054] Based on the fact that in the existing production process of electronic-grade isopropanol, isopropanol forms azeotropes with isopropyl ether and acetone, making it difficult to achieve a clear separation of isopropyl ether and acetone. This leads to the problem that the purity of isopropanol products cannot meet the requirements of high-grade electronic-grade isopropanol. In addition, the extractive distillation separation process consumes a large amount of energy, is prone to introducing other impurities, and cannot achieve the simultaneous and efficient deep removal of trace isopropyl ether and acetone impurities in isopropanol. The present invention provides a method for producing electronic-grade isopropanol by adsorptive removal of trace impurities, which includes the following steps: 1) Passing the isopropanol raw material into an adsorption separation device filled with an adsorbent material having excellent adsorption selectivity for trace isopropyl ether and acetone at a certain space velocity; 2) Effectively removing isopropyl ether and acetone from the isopropanol solution through the adsorption separation section, and collecting the raffinate effluent, which is the purified electronic-grade isopropanol; 3) After the adsorption is completed, through the adsorbent regeneration section, collecting the desorption effluent, which is the isopropanol solution rich in isopropyl ether and acetone impurities. By the adsorption separation method provided by the present invention and filling the adsorption separation device with an adsorbent having high-resolution adsorption selectivity for trace isopropyl ether and acetone, the efficient capture of trace isopropyl ether and acetone can be achieved, thereby effectively removing them from the isopropanol solution and achieving the purpose of refining electronic-grade isopropanol. The isopropyl ether in the isopropanol obtained by adsorption treatment can be removed to less than 1 ppm, and the acetone can be reduced to less than 2 ppm, further enhancing the application of isopropanol in high-precision and advanced technology fields such as integrated circuits and the commercial value of isopropanol products. Through the adsorption separation method proposed by the present invention, coupling with a high-resolution identification adsorbent material with specific functions, it can be widely applied to the efficient capture of trace impurities in other necessary occasions, such as the adsorption and removal of trace organic substances such as benzene in water.

[0055] Thus, it can effectively solve the problem of the failure to clearly separate trace organic impurities such as isopropyl ether and acetone in the existing production process of electronic-grade ultrapure isopropanol, and at the same time, it can also effectively solve the problems of the large energy consumption of the extractive distillation separation process, the easy introduction of other impurities, and the inability to achieve the simultaneous and efficient deep removal of trace isopropyl ether and acetone impurities in isopropanol.

[0056] It should be understood that within the scope of the present invention, the above technical features of the present invention and the technical features specifically described below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be elaborated one by one here.

[0057] This embodiment is implemented on the premise of the technical solution of the present invention, and gives detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following embodiments.

[0058] The following are more detailed implementation cases, further illustrating the technical solution of the present invention and the technical effects that can be obtained through the following implementation cases.

[0059] In the following examples, unless otherwise specified, raw material reagents or treatment techniques are conventional commercially available products or conventional treatment techniques in the art, and the treatment conditions are normal temperature and pressure.

[0060] In the following examples, the concentration of ammonia water used is 25 - 28 wt.%.

[0061] Example 1

[0062] A kind of MAF-6, its preparation method includes:

[0063] Dissolve 4 g of zinc oxide in a mixed solution of 50 g of deionized water and 200 g of ammonia water to obtain reaction solution 1. Dissolve 8 g of 2-ethylimidazole and 1 g of cyclohexane in 250 g of ethanol solution to obtain reaction solution 2. Slowly drop reaction solution 1 into reaction solution 2, and continuously stir and react at room temperature for 1.5 h to obtain a crystallization product. Centrifuge and wash the obtained crystallization product with methanol 3 times, and vacuum dry at 150 °C for 5 h to obtain MAF-6.

[0064] The application of the above MAF-6 in selectively adsorbing isopropyl ether and acetone from isopropanol includes:

[0065] Weigh 1 g of the above synthesized MAF-6 and add it to 10 g of an isopropanol solution containing 494 ppm of isopropyl ether and 1519 ppm of acetone. After sealing, oscillate and stir in a 25 °C constant temperature water bath for 6 h. Analyze by gas chromatograph, the concentration of isopropyl ether in the isopropanol solution after adsorption is 138 ppm, and the concentration of acetone is 1147 ppm. Thus, the removal rate of isopropyl ether is 72.1%, and the removal rate of acetone is 24.5%.

[0066] Example 2

[0067] A kind of MAF-6, its preparation method includes:

[0068] Dissolve 4 g of zinc oxide in a mixed solution of 50 g of deionized water and 200 g of ammonia water to obtain reaction solution 1. Dissolve 8 g of 2-ethylimidazole and 3 g of cyclohexane in 250 g of ethanol solution to obtain reaction solution 2. Slowly drop reaction solution 1 into reaction solution 2, and continuously stir and react at room temperature for 1.5 h to obtain a crystallization product. Centrifuge and wash the obtained crystallization product with methanol 3 times, and vacuum dry at 150 °C for 5 h to obtain MAF-6.

[0069] The application of the above MAF-6 in selectively adsorbing isopropyl ether and acetone from isopropanol includes:

[0070] Weigh 3 g of the synthesized MAF-6 above and add it to a polytetrafluoroethylene fixed-bed adsorption column. Fill appropriate amounts of quartz sand at both the upper and lower ends of the adsorption column, and use a constant-temperature water bath to maintain the column temperature at 25 °C. At the start of the adsorption experiment, use a constant-flow pump to control the isopropanol solution to flow into the adsorption column at a flow rate of 0.3 mL / min (the concentration of isopropyl ether in the isopropanol solution is 237 ppm, and the concentration of acetone is 7 ppm). Start timing when the first drop of liquid drips out from the bed outlet, collect the filtrate in the first 20 min and analyze the concentration of isopropyl ether in the isopropanol solution after adsorption by gas chromatography to be 0, and the concentration of acetone is 2 ppm. Thus, the removal rate of isopropyl ether can be obtained as 100%, and the removal rate of acetone is 71.4%.

[0071] Example 3

[0072] A kind of MAF-6, its preparation method includes:

[0073] Dissolve 2 g of zinc oxide in a mixed solution of 50 g of deionized water and 200 g of ammonia water to obtain reaction solution one. Dissolve 4 g of 2-ethylimidazole and 3 g of cyclohexane in 250 g of ethanol solution to obtain reaction solution two. Slowly drip reaction solution one into reaction solution two, and continuously stir and react at room temperature for 1.5 h. Centrifuge and wash the obtained crystallization product with methanol 3 times, and vacuum dry at 150 °C for 5 h to obtain MAF-6.

[0074] The application of the above MAF-6 in selectively adsorbing isopropyl ether and acetone from isopropanol includes:

[0075] Weigh 10 g of the synthesized MAF-6 above and add it to a polytetrafluoroethylene fixed-bed adsorption column. Fill appropriate amounts of quartz sand at both the upper and lower ends of the adsorption column, and use a constant-temperature water bath to maintain the column temperature at 25 °C. At the start of the adsorption experiment, use a constant-flow pump to control the isopropanol solution to flow into the adsorption column at a flow rate of 0.3 mL / min (the concentration of isopropyl ether in the isopropanol solution is 54 ppm, and the concentration of acetone is 41 ppm). Start timing when the first drop of liquid drips out from the bed outlet, collect the filtrate every 5 min and analyze by gas chromatography. Thus, the concentration change curves of isopropyl ether and acetone can be obtained, as Figure 1 shown, within the experimental range, the removal rate of isopropyl ether is 100%, and the removal rate of acetone is 86.1 - 88.0%.

[0076] Example 4

[0077] After conducting the experiment according to the experimental steps in Example 2, use a flowmeter to control the desorbent CO2 at 5 h -1The airspeed was introduced into the adsorption column bed for 1 h, and the desorption temperature was controlled at 40 °C. After the desorption regeneration was completed, the corresponding adsorption experiment was continued according to the experimental steps in Example 2. The filtrate in the first 20 min was collected and analyzed by a gas chromatograph, and the removal rates of isopropyl ether and acetone were calculated and compared with the fresh adsorbent. This process was repeated three times, and the results are as Figure 2 shown. After the adsorbent was regenerated three times, the removal rate of isopropyl ether was still higher than 90%, and the removal rate of acetone was still higher than 60%.

[0078] Example 5

[0079] The MAF-6 material synthesized in Example 1 was taken for water contact angle measurement. Before the measurement, the powder sample was pressed into a tablet under a pressure of 1 MPa, and 1 μL of water droplet was dropped onto the sample surface. The contact angle was determined by analyzing the water droplet image. The water contact angle of this material was 69°.

[0080] The MAF-6 material synthesized in Example 2 was taken for water contact angle measurement. Before the measurement, the powder sample was pressed into a tablet under a pressure of 1 MPa, and 1 μL of water droplet was dropped onto the sample surface. The contact angle was determined by analyzing the water droplet image. The water contact angle of this material was 112°.

[0081] Comparative Example 1

[0082] A Zif material, the preparation method includes:

[0083] Weigh 5 g of 2-methylimidazole, 10 g of zinc nitrate hexahydrate, 6 g of sodium formate anhydrous, and 1 g of cetyltrimethylammonium bromide and place them in a beaker. Then add 150 g of water and 150 g of N,N-dimethylformamide, and ultrasonically dissolve them fully. Transfer this completely dissolved mixed solution into a stainless steel reaction kettle made of polytetrafluoroethylene, and crystallize at 90 °C for 24 h. After the crystallization is completed, the product is centrifugally washed several times with deionized water, the solid is recovered, and dried at 90 °C for 6 h to obtain the corresponding Zif material.

[0084] The application of the above Zif material in selectively adsorbing isopropyl ether and acetone from isopropanol includes:

[0085] Weigh 1 g of the above synthesized Zif sample and add it to 10 g of an isopropanol solution containing 494 ppm of isopropyl ether and 1519 ppm of acetone. After sealing, shake and stir in a constant temperature water bath at 25 °C for 6 h. By analyzing with a gas chromatograph, the concentration of isopropyl ether in the isopropanol solution after adsorption was 457 ppm, and the concentration of acetone was 1085 ppm. Thus, the removal rate of isopropyl ether was 7.5%, and the removal rate of acetone was 28.6%.

[0086] Comparing Example 1 with Comparative Example 1, it can be seen that the MAF-6 prepared in Example 1 shows significant adsorption selectivity for trace amounts of isopropyl ether and acetone in isopropanol solution.

[0087] Comparative Example 2

[0088] A Zif material, the preparation method includes:

[0089] Weigh 5 g of zinc nitrate hexahydrate and 5 g of cobalt nitrate hexahydrate and place them in a beaker. Add 60 g of water and 90 g of N,N-dimethylformamide thereto, and ultrasonically dissolve them thoroughly. Weigh 1 g of agar powder and add it to the mixed solution, heat and stir to completely dissolve the agar powder, and then cool until the solution becomes gel-like. Weigh 15 g of 2-methylimidazole and add it to 60 g of water and 90 g of N,N-dimethylformamide, and ultrasonically obtain the corresponding solution. Quickly add the above solution to the gel-like mixture, and let it stand for crystallization at 25 °C for 72 h. After the crystallization is completed, completely dissolve this mixture under heating and stirring conditions, centrifuge and wash the product several times with deionized water, recover the solid, and dry it at 90 °C for 6 h to obtain the corresponding Zif material.

[0090] The application of the above Zif material in selectively adsorbing isopropyl ether and acetone from isopropanol includes:

[0091] Weigh 1 g of the synthesized Zif sample above and add it to 10 g of an isopropanol solution containing 494 ppm of isopropyl ether and 1519 ppm of acetone. After sealing, oscillate and stir in a constant temperature water bath at 25 °C for 6 h. Analyze by gas chromatograph that the concentration of isopropyl ether in the isopropanol solution after adsorption is 465 ppm, and the concentration of acetone is 1040 ppm. From this, the removal rate of isopropyl ether can be obtained as 5.9%, and the removal rate of acetone is 31.5%.

[0092] Comparative Example 3

[0093] A Zif material, the preparation method includes:

[0094] Dissolve 3 g of zinc oxide in a mixed solution of 50 g of deionized water and 200 g of ammonia water to obtain Reaction Solution 1. Dissolve 6 g of 2-propylimidazole and 1 g of cyclohexane in 250 g of ethanol solution to obtain Reaction Solution 2. Slowly drip Reaction Solution 1 into Reaction Solution 2, and continuously stir and react at room temperature for 1.5 h. Centrifuge and wash the obtained crystallization product 3 times with methanol, and vacuum dry it at 150 °C for 5 h to obtain the corresponding Zif material.

[0095] The application of the above Zif material in selectively adsorbing isopropyl ether and acetone from isopropanol includes:

[0096] Weigh 1 g of the above-synthesized Zif sample and add it to 10 g of an isopropanol solution containing 494 ppm of isopropyl ether and 1519 ppm of acetone. After sealing, shake and stir it in a constant temperature water bath at 25 °C for 6 h. Analyze the concentration of isopropyl ether in the isopropanol solution after adsorption by a gas chromatograph, which is 486 ppm, and the concentration of acetone is 1393 ppm. From this, the removal rate of isopropyl ether is 1.6%, and the removal rate of acetone is 8.3%.

[0097] Comparing Example 1 with Comparative Example 3 shows that the raw materials for preparing the adsorbent have a significant impact on the material properties. In Comparative Example 3, when 2-propylimidazole was used to replace 2-ethylimidazole and the amounts of zinc oxide and imidazole reagents were adjusted slightly, the removal effect of the prepared material changed significantly, indicating that not all similar materials with similar preparation methods can exhibit the same removal performance of isopropyl ether and acetone as MAF-6 used in the present invention.

[0098] Comparative Example 4

[0099] Add 500 g of industrial isopropanol with a purity of 99.70% (isopropyl ether content: 211 ppm; acetone content: 97 ppm) to the bottom of a batch distillation column with 50 theoretical plates, and introduce nitrogen to displace the air for 1 h. After the gas displacement is completed, turn on the heating function, maintain the bottom temperature at 90 °C, set the temperature of the top condenser at 20 °C, and set the reflux ratio of the top splitter at 20:1. Collect the top products of different fractions according to the temperature difference at the top. The product with a distillation temperature of 81 - 84 °C is refined isopropanol. Analyze the top product by a gas chromatograph, and the concentration of isopropyl ether is 154 ppm, and the concentration of acetone is 58 ppm.

[0100] Comparing Example 1 with Comparative Example 4 shows that the conventional distillation process is difficult to effectively remove trace isopropyl ether and acetone in isopropanol. Under the same raw material composition conditions, the removal effect of the above organic impurities is significantly inferior to that of using MAF-6 in Example 1. Moreover, Example 1 completes the impurity removal at normal temperature and pressure, which has significant advantages in equipment cost and energy consumption cost compared with the distillation process, and thus has good industrial application prospects.

[0101] The present invention first proposes a method for adsorptive removal of trace impurities to produce electronic-grade isopropyl alcohol. Compared with the electronic-grade isopropyl alcohol production processes reported in other studies, the adsorption separation process of the present invention can deeply remove isopropyl ether and acetone that are difficult to be clearly separated by ordinary distillation, thereby greatly improving the purity of the electronic-grade isopropyl alcohol product. Compared with the separation processes of the isopropyl ether / isopropyl alcohol system and the acetone / isopropyl alcohol system (mainly extractive distillation processes), the adsorption separation process of the present invention can not only effectively adsorb and remove trace isopropyl ether and acetone impurities in isopropyl alcohol at the same time, but also effectively solve the problems of high energy consumption in the existing extractive distillation separation process and the possible introduction of extractant impurities that cannot be completely separated into the product. By the adsorption separation method proposed by the present invention and coupling with an adsorbent material with high-resolution identification function, an efficient trace impurity capture and separation process applicable to other necessary occasions can be designed, which greatly broadens the application of adsorption separation in aspects such as solvent purification and impurity removal. According to the method proposed by the present invention, by changing the adsorbent material with high-resolution identification function, an efficient trace impurity capture and separation process applicable to other necessary occasions can be designed.

[0102] It should be understood that according to the ideas and methods proposed by the present invention, those skilled in the art can easily propose new adsorption separation schemes based on the types and contents of impurities in typical electronic-grade isopropyl alcohol, coupling with other adsorbent materials with high-resolution identification functions, not limited to the effective removal of trace isopropyl ether and acetone. The creativity of the present invention mainly lies in first proposing a method for adsorptive removal of trace impurities to produce electronic-grade isopropyl alcohol, and thus proposing a method for efficiently removing impurities in electronic-grade isopropyl alcohol by dynamic adsorption separation and coupling with an adsorbent material with high-resolution identification function.

[0103] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the invention. Obviously, those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative labor. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A method for adsorptive removal of isopropyl ether and / or acetone from isopropanol, characterized in that, The method includes: contacting MAF-6 with an isopropanol solution containing isopropyl ether and / or acetone.

2. The method for adsorptive removal of isopropyl ether and / or acetone from isopropanol according to claim 1, characterized in that, The method for contacting the MAF-6 with the isopropanol solution is selected from one of a liquid-phase dynamic adsorption method, a gas-phase dynamic adsorption method, a liquid-phase static adsorption method, or a gas-phase static adsorption method; The liquid-phase dynamic adsorption method includes: flowing the isopropanol solution through an adsorbent bed filled with MAF-6; The gas-phase dynamic adsorption method includes: pre-vaporizing the isopropanol solution and flowing it through an adsorbent bed filled with MAF-6; The liquid-phase static adsorption method includes: adding MAF-6 to the isopropanol solution; The gas-phase static adsorption method includes: placing MAF-6 in the vapor environment of the isopropanol solution.

3. The method for adsorptive removal of isopropyl ether and / or acetone from isopropanol according to claim 2, wherein The adsorption temperature is 25 to 120 °C, and the feed space velocity of the isopropanol solution is 0.1 to 5 h -1 .

4. The method for adsorptive removal of isopropyl ether and / or acetone from isopropanol according to claim 2, wherein The adsorber used is selected from one of a fixed-bed adsorber, a moving-bed adsorber, or a fluidized-bed adsorber.

5. The method for adsorptive removal of isopropyl ether and / or acetone from isopropanol according to claim 1, wherein In the isopropanol solution, the content of isopropyl ether is not higher than 2000 ppm.

6. The method for adsorptive removal of isopropyl ether and / or acetone from isopropanol according to claim 1, characterized in that In the isopropanol solution, the content of acetone is not higher than 2000 ppm.

7. The method for adsorptive removal of isopropyl ether and / or acetone from isopropanol according to claim 1, wherein The preparation method of the MAF-6 includes the following steps: Mix 2-ethylimidazole, cyclohexane, and an alcohol solvent to obtain a first reaction solution; mix zinc oxide, water, and ammonia water to obtain a second reaction solution; Stir and react the first reaction solution with the second reaction solution, and then purify to obtain.

8. The method for adsorptive removal of isopropyl ether and / or acetone in isopropanol according to claim 7, wherein The mass ratio of the 2-ethylimidazole, cyclohexane, alcohol, zinc oxide, water, and ammonia water is (4-8):(1-3):250:(2-4):(48-5):(180-220).

9. The method for adsorptive removal of isopropyl ether and / or acetone from isopropanol according to claim 7, wherein In the stirring reaction, the reaction temperature is room temperature, and the reaction time is 1.5-2 h.

10. The method for adsorptive removal of isopropyl ether and / or acetone from isopropanol according to claim 1, characterized in that, It also includes desorbing and regenerating the MAF-6; The desorption gas used is selected from one or more of air, nitrogen, helium, argon, hydrogen or carbon dioxide; the desorption temperature is 25 to 60 °C, and the desorption space velocity is 1 to 10 h -1 .

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