Electronic-grade isopropanol purification device

Abstract

The utility model provides an electronic grade isopropanol purification device, including the raw material tank, dehydration unit, filter, rectification tower and adsorption unit that set continuously in proper order, dehydration unit removes the moisture in industrial grade isopropanol in the raw material tank through molecular sieve to make the isopropanol water content control in 40-60ppm, there are provided a plurality of rectification tower and are connected in proper order, the adsorption unit is connected in proper order, and the adsorption unit is connected in proper order. The content of metal ions in the tower top condensate of the tail-end rectifying tower is less than 50ppt, and the adsorption unit reduces the content of the metal ions in the tower top condensate of the tail-end rectifying tower to 10ppt by using a resin adsorbent to output electronic-grade isopropanol. The electronic-grade isopropanol purification device provided by the utility model can be used for finally preparing a G5-grade electronic-grade isopropanol product of which the metal ions are less than 10ppt.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of isopropanol purification, and particularly relates to an electronic-grade isopropanol purification device. BACKGROUND

[0002] Electronic-grade isopropanol is an innovative product combining electronic technology and chemical materials. As an indispensable wet electronic chemical reagent, electronic-grade isopropanol is mainly used in wafer cleaning, packaging testing and other links, has a broad market prospect and great development potential. Due to its high purity, high quality requirements, harsh environmental cleanliness requirements and high product added value.

[0003] Traditional separation and purification methods include rectification, adsorption and membrane separation. Rectification can be further divided into azeotropic rectification, extractive rectification distillation, sub-boiling distillation, reduced pressure distillation and low temperature distillation. Among them, adsorption and membrane separation can only remove part of the impurities, and the quality grade of the obtained isopropanol is low. In the rectification treatment method, azeotropic rectification and extractive rectillation introduce new materials, which can easily affect the quality of isopropanol. Sub-boiling rectification, reduced pressure rectification and low temperature rectification have high energy consumption, low product grade and low product yield. The foregoing two schemes have not been put into continuous production in actual devices, and the process is relatively complex, and there is no actual engineering case. In addition, there are many process treatment types (multiple filtration, cation and anion removal, dehydration treatment, nanofiltration, etc.) in the prior art, which can easily introduce other impurities and cause fluctuations in product quality. SUMMARY

[0004] In order to solve the above problems existing in the prior art, the present application provides an electronic-grade isopropanol purification device to solve the above technical defect problems.

[0005] The present application provides an electronic-grade isopropanol purification device, which comprises a raw material tank, a dehydration unit, a filter, a rectification tower and an adsorption unit arranged in sequence. The dehydration unit removes water in industrial-grade isopropanol in the raw material tank by molecular sieve to control the water content of isopropanol to 40-60 ppm. The rectification tower is provided with a plurality of rectification towers connected in sequence. The metal ion content in the condensate at the top of the last rectification tower is less than 50 ppt. The adsorption unit uses a resin adsorbent to reduce the metal ion content in the condensate at the top of the last rectification tower to 10 ppt to output electronic-grade isopropanol. The device can realize efficient purification from industrial-grade isopropanol to electronic-grade isopropanol, and finally achieve the G5-grade electronic-grade isopropanol standard with a metal ion content of less than 10 ppt.

[0006] In some specific embodiments, the distillation column includes a primary distillation column, a secondary distillation column, and a tertiary distillation column arranged sequentially. The condensate from the top of the primary distillation column is fed into the secondary distillation column, and the bottom liquid from the secondary distillation column is fed into the tertiary distillation column. By fully utilizing the high purity of the condensate from the top of the column and the high impurity enrichment of the bottom liquid, staged distillation improves the reliability and continuity of the process, making it suitable for large-scale production.

[0007] In some specific embodiments, the first-stage distillation column has 40-60 theoretical plates, a pressure of 0-2 bar, a top temperature of 65-90°C, and a reflux ratio of 0.5-10, controlling the metal ion concentration in the overhead condensate to below 1 ppb; the second-stage distillation column has 40-60 theoretical plates, a pressure of 0-2 bar, a top temperature of 65-90°C, and a reflux ratio of 0.5-15; the third-stage distillation column has 40-60 theoretical plates, a pressure of 0-2 bar, a top temperature of 65-90°C, and a reflux ratio of 0.5-15, controlling the metal ion concentration in the overhead condensate to below 50 ppt. By removing metal ions stage by stage through first-, second-, and third-stage distillation columns, and by precisely controlling the number of plates, pressure, temperature, and reflux ratio of each stage, the staged removal and efficient purification of metal ions can be achieved.

[0008] In some specific embodiments, the distillation column is equipped with 3 to 7 layers of distributors and packing zones. The packing zones consist of bulk packing with Raschig rings or spiral rings, or structured packing with corrugated packing or wire mesh packing. This arrangement ensures sufficient gas-liquid contact, improving separation efficiency.

[0009] In some specific embodiments, a reboiler is provided at the bottom of the distillation column, including a forced circulation or siphon reboiler. This arrangement improves heat transfer efficiency and reduces energy consumption.

[0010] In some specific embodiments, the molecular sieve includes 3A, 4A, or 5A molecular sieves, and the molecular sieve shape is granular, particulate, or flake-like, with a particle size of 1–3 mm. This configuration improves the moisture adsorption capacity, ensuring that the moisture content in industrial-grade isopropanol is controlled within 40–60 ppm.

[0011] In some specific embodiments, a transfer pump is installed between the raw material tank and the dehydration unit. The transfer pump delivers industrial-grade isopropanol from the raw material tank into the dehydration unit and filter at a flow rate of 2000–3000 L / h. The transfer pump provides a continuous and stable flow rate, improving the overall operating efficiency of the unit and avoiding the impact of flow rate fluctuations on subsequent purification steps.

[0012] In some specific embodiments, the filter element is made of polytetrafluoroethylene (PTFE) or modified PTFE. It possesses excellent chemical stability and corrosion resistance, ensuring filtration efficiency and equipment lifespan.

[0013] In some specific embodiments, the filter has a filtering accuracy of 0.5 μm, 1 μm or 3 μm. The filter has an accuracy range (0.5 μm, 1 μm or 3 μm) that can be selected according to the impurity content and purity requirements, further improving the filtering accuracy and adaptability.

[0014] In some specific embodiments, the resin adsorbent includes a mixed bed resin or a weakly basic anion exchange resin. The mixed bed resin and the weakly basic anion exchange resin have excellent adsorption performance on metal ions, and can further reduce the metal ion content in the end rectification column condensate from 50 ppt to within 10 ppt.

[0015] In some specific embodiments, the resin adsorbent has a loading mode including fixed bed stacking, boiling bed bulk loading, fluidized bed bulk loading or suspended bed bulk loading. The fixed bed stacking, boiling bed bulk loading, fluidized bed bulk loading or suspended bed bulk loading of the resin loading mode is provided to adapt to different process requirements, and further improve the adsorption effect.

[0016] Compared with the prior art, the beneficial results of the electronic grade isopropanol purification device are as follows:

[0017] The process route selection and internal packing selection of the electronic grade isopropanol purification device can avoid the introduction of unnecessary impurities, and the process is simple, convenient to operate and stable in working condition; through the selection of the dehydration system, the internal design of the rectification tower and the type of the reboiler, the process energy consumption is reduced, and the yield of the product is ensured; finally, the G5 grade electronic grade isopropanol product with less than 10 ppt of metal ions can be obtained. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings are included to provide a further understanding of embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain the principles of the present application. Other embodiments and many of the intended advantages of the present application will be readily appreciated as the same becomes better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.

[0019] Figure 1 is a structural schematic diagram of an electronic grade isopropanol purification device according to an embodiment of the present application.

[0020] The meanings of the numbers in the figure are as follows: 1 - raw material tank, 2 - first conveying pump, 3 - first resin tank, 4 - filter, 5 - first-stage rectification tower, 6 - first reboiler, 7 - second conveying pump, 8 - first condenser, 9 - first collection tank, 10 - third conveying pump, 11 - second-stage rectification tower, 12 - second reboiler, 13 - fourth conveying pump, 14 - second condenser, 15 - second collection tank, 16 - fourth conveying pump, 17 - third-stage rectification tower, 18 - third reboiler, 19 - fifth conveying pump, 20 - third condenser, 21 - third collection tank, 22 - sixth conveying pump, 23 - second resin tank, 24 - finished product tank, 25 - seventh conveying pump. DETAILED DESCRIPTION

[0021] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration illustrative embodiments in which the application can be practiced. For purposes of explanation and illustration, directional terms are used with reference to the orientation of the described figures. Because components of embodiments can be positioned in a number of different orientations, the directional terminology is used in connection with the illustrative embodiments for purposes of illustration and description only. It is to be understood that other embodiments can be utilized and logical substitutions and alterations of described embodiments can be made without departing from the scope of the present application. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present application is defined by the appended claims.

[0022] The utility model provides a kind of electronic grade isopropanol purification device, Figure 1 The structure diagram of electronic grade isopropanol purification device of the embodiment of the utility model is shown, Figure 1 As shown in the figure, industrial grade isopropanol is stored in raw material tank 1, and is conveyed to first resin tank 3 by first conveying pump 2 at a constant flow rate (preferably, the control flow rate is 2000-3000 L / h). First resin tank 3 is a dehydration unit, filled with 3A, 4A or 5A molecular sieve inside, for removing water in isopropanol, so that its water content is controlled at 40-60 ppm. After dehydration, isopropanol flows into filter 4 through pipeline, and the filter core material of filter 4 is polytetrafluoroethylene (PTFE) or modified polytetrafluoroethylene (N-PTFE), and the filtration accuracy can be selected as 0.5 μm, 1 μm or 3 μm according to requirements. After filtration, isopropanol is treated by multi-stage rectification, preferably, by three-stage rectification tower in the present application, specifically as follows:

[0023] Primary distillation: The filtered isopropyl alcohol is pumped into the primary distillation column 5, which has 40-60 theoretical plates, and is operated at a pressure of 0-2 bar, a column top temperature of 65-90°C, and a reflux ratio of 0.5-10. The primary distillation column 5 is heated by the first reboiler 6, and the column top gas is condensed by the first condenser 8. The column top condensate is collected in the first collection tank 9, and the column bottom liquid is isopropyl alcohol containing high-boiling impurities, which is output as industrial-grade isopropyl alcohol by the second delivery pump 7. The purpose of the primary distillation is to remove high-boiling impurities and control the metal ion content in the column top condensate to be below 1 ppb.

[0024] Secondary distillation: The column top condensate of the first collection tank 9 is delivered to the secondary distillation column 11 by the third delivery pump 10. The secondary distillation column 11 is provided with 40-60 theoretical plates, and is operated at a pressure of 0-2 bar, a column top temperature of 65-90°C, and a reflux ratio of 0.5-15. During the distillation process, the second reboiler 12 heats the column bottom, and the column top condensate is collected in the second collection tank 15 by the second condenser 14 and can be output as industrial-grade isopropyl alcohol by the fourth delivery pump 16. The column bottom liquid is delivered to the tertiary distillation column 17 by the fourth delivery pump 13.

[0025] Tertiary distillation: The column bottom liquid of the secondary distillation column is delivered to the tertiary distillation column 17 by the fourth delivery pump 13. The tertiary distillation column 17 also has 40-60 theoretical plates, and is operated at a pressure of 0-2 bar, a column top temperature of 65-90°C, and a reflux ratio of 0.5-15. The distillation process is heated by the third reboiler 18, and the column top condensate is cooled by the third condenser 20 and collected in the third collection tank 21. The column bottom liquid is output as industrial-grade isopropyl alcohol by the fifth delivery pump 19. The purpose of the tertiary distillation is to reduce the metal ion content in the column top condensate to below 50 ppt.

[0026] The column top condensate of the tertiary distillation column 17 is delivered to the second resin tank 23 by the sixth delivery pump 22. The second resin tank 23 serves as an adsorption unit, which is filled with mixed bed resin or weakly basic anion exchange resin, and is used to further remove metal ions, reducing the metal ion content in the isopropyl alcohol to within 10 ppt. The electronic-grade isopropyl alcohol treated by the adsorption unit is pumped into the finished product tank 24 for storage, and the final electronic-grade isopropyl alcohol meeting the G5 grade standard is obtained. The G5-grade isopropyl alcohol is filled as needed by the seventh delivery pump 25.

[0027] In specific embodiments, the distillation column is provided with 3-7 layers of distributors and packing zones to ensure sufficient gas-liquid contact and improve separation efficiency. The packing zone can be filled with bulk packing (such as Raschig rings, spiral rings) or structured packing (such as corrugated packing, wire mesh packing) according to production needs to adapt to different purity requirements and process conditions.

[0028] In specific embodiments, the reboiler comprises a forced circulation or siphon reboiler. The reboiler provides the heat required by the column bottom material to maintain the continuous distillation process in the column. In the rectification process, the liquid mixture at the column bottom needs to be heated to the boiling state so that the light components therein can evaporate and rise to the top of the column for condensation separation, while the heavy components remain at the bottom. The reboiler heats the column bottom material by an external heat source (such as steam, hot water or heat conducting oil, etc.) to ensure that the heat energy is uniformly and stably transferred to the column bottom material. The reboiler is designed with a high-efficiency heat exchange structure, which can fully utilize the heat energy, avoid energy waste, and can adjust the heating amount in time according to the changes in the distillation conditions in the column, so as to maintain the stability of the temperature in the column and the optimization of the distillation efficiency.

[0029] In specific embodiments, the molecular sieve has a shape of granular, particulate or flaky, and a particle size of 1-3 mm. The optimized design improves the water adsorption capacity, ensuring that the water content in the industrial-grade isopropyl alcohol is controlled to be not more than 50 ppm. Different types of molecular sieves (such as 3A, 4A or 5A) can be flexibly selected according to the water content of isopropyl alcohol to adapt to different process requirements.

[0030] In specific embodiments, the resin tank adsorbent of the second resin tank 23 is a mixed bed resin composed of hydrogen type strong acid cation exchange resin and hydrogen oxygen type strong base anion exchange resin, or a macroporous weak base anion exchange resin of styrene-divinylbenzene copolymer. The specific type of the mixed bed resin is Bleight mixed bed resin HCL5-10 75-150 40-100, and its characteristics include: it is a ready-to-use resin composed of gel type strong acid cation exchange resin and strong base anion exchange resin and has been pre-mixed and regenerated; it is mixed and compounded according to specific chemical equivalents after high transformation and special purification treatment; it is mainly applied to direct purification of water, preparation of electronic industry pure water, and subsequent mixed bed fine treatment of other various water treatment processes. The specific type of the macroporous weak base anion exchange resin of styrene-divinylbenzene copolymer is D201, and its appearance is milky white to light yellow opaque spherical particles, and its performance indicators are: the factory type is chlorine type; the water content is 50.00-60.00%; the maximum regeneration capacity is ≥4.00 mmol / g; the strong group capacity is ≥3.70 mmol / g; the volume full exchange capacity is ≥1.20 mmol / ml; the wet apparent density is 0.65-0.73 g / ml; the wet true density is 1.060-1.100 g / ml; the range particle size (0.315-1.250 mm) is ≥95%, and the lower limit particle size (<0.315 mm) is ≤1; the effective particle size is 0.400-0.700 mm; the uniformity coefficient is ≤1.60; and the sphericity rate is ≥90.00%.

[0031] In a specific embodiment, the packing mode of the adsorbent is fixed bed, boiling bed, fluidized bed or suspended bed. In a specific example, the second resin tank 23 adopts fixed bed packing, which is composed of a vertical cylindrical container, filled with adsorbent material (such as mixed bed resin or weak base anion exchange resin) inside, and adopts fixed bed packing mode. The liquid inlet is located at the top of the container, used to introduce the condensate from the top of the third rectifying tower; the adsorption layer is evenly filled with resin material in the adsorption zone, fixed and not moving, and the liquid passes from top to bottom; the support layer is a layer of support grid or filter screen set below the resin, used to fix the resin particles and prevent them from entering the downstream pipeline; the liquid outlet is located at the bottom of the container, used to output the high-purity isopropyl alcohol treated by adsorption; a porous distributor is installed below the liquid inlet to ensure uniform distribution of the liquid on the surface of the resin layer, avoiding early saturation of the resin caused by excessive local flow. A porous support plate or filter screen is installed above the liquid outlet, which can uniformly collect the liquid and fix the resin particles to prevent their loss.

[0032] Obviously, those skilled in the art can make various modifications and changes to the embodiments of the present application without departing from the spirit and scope of the present application. In this way, if these modifications and changes are within the scope of the claims of the present application and their equivalents, the present application also aims to cover these modifications and changes. The word "comprising" does not exclude the presence of other elements or steps not listed in the claims. The simple fact that certain measures are described in mutually different dependent claims does not mean that the combination of these measures cannot be used to advantage. Any reference signs in the claims should not be considered as limiting the scope.

Claims

1. An electronic grade isopropanol purification apparatus, characterized by, The device comprises a raw material tank, a dehydration unit, a filter, a rectifying tower and an adsorption unit arranged in sequence, the dehydration unit removes water in industrial-grade isopropyl alcohol in the raw material tank by molecular sieve to control the water content of isopropyl alcohol at 40-60 ppm, the rectifying tower is provided with multiple rectifying towers connected in sequence, the content of metal ions in the condensate at the top of the last rectifying tower is less than 50 ppt, and the adsorption unit uses a resin adsorbent to reduce the content of metal ions in the condensate at the top of the last rectifying tower to 10 ppt to output electronic-grade isopropyl alcohol.

2. The electronic grade isopropanol purification apparatus of claim 1, wherein, The rectifying tower comprises a first-stage rectifying tower, a second-stage rectifying tower and a third-stage rectifying tower arranged in sequence, the condensate at the top of the first-stage rectifying tower is connected to the second-stage rectifying tower, and the liquid at the bottom of the second-stage rectifying tower is connected to the third-stage rectifying tower.

3. The electronic grade isopropanol purification apparatus of claim 2, wherein, The first-stage rectifying tower has 40-60 theoretical plates, a pressure of 0-2 bar, a top temperature of 65-90℃, a reflux ratio of 0.5-10, and the content of metal ions in the condensate at the top is controlled to be less than 1 ppb; the second-stage rectifying tower has 40-60 theoretical plates, a pressure of 0-2 bar, a top temperature of 65-90℃, and a reflux ratio of 0.5-15; and the third-stage rectifying tower has 40-60 theoretical plates, a pressure of 0-2 bar, a top temperature of 65-90℃, and a reflux ratio of 0.5-15, and the content of metal ions in the condensate at the top is controlled to be less than 50 ppt.

4. The electronic grade isopropanol purification apparatus of claim 1, wherein, The rectifying tower is provided with 3-7 layers of distributors and a packing zone, the packing zone is bulk packing of Raschig rings or spiral rings, or structured packing of corrugated packing or wire mesh packing.

5. The electronic grade isopropanol purification apparatus according to claim 1 or 2, characterized by, The rectifying tower is provided with a tower bottom reboiler, and the reboiler comprises a forced circulation type or a siphon type reboiler.

6. The electronic grade isopropanol purification apparatus of claim 1, wherein, The molecular sieve comprises 3A, 4A or 5A molecular sieve, and the molecular sieve has a shape of granular, particulate or sheet, and a particle size of 1-3 mm.

7. The electronic grade isopropyl alcohol purification apparatus as claimed in claim 1, wherein, A conveying pump is arranged between the raw material tank and the dehydration unit, and the conveying pump feeds the industrial-grade isopropyl alcohol in the raw material tank into the dehydration unit and the filter at a flow rate of 2000-3000 L / h.

8. The electronic grade isopropyl alcohol purification apparatus as claimed in claim 1, wherein, The filter element of the filter is made of polytetrafluoroethylene or modified polytetrafluoroethylene, and the filter has a filtering accuracy of 0.5 μm, 1 μm or 3 μm.

9. The electronic grade isopropyl alcohol purification apparatus as claimed in claim 1, wherein, The resin adsorbent comprises a mixed bed resin or a weakly basic anion exchange resin.

10. The electronic grade isopropanol purification apparatus of claim 1, wherein, The resin adsorbent is loaded in a fixed bed type, a boiling bed bulk, a fluidized bed bulk or a suspended bed type.

Images