A purification device, its use and a method for purifying dimethyl carbonate

Abstract

The application belongs to the technical field of separation and purification, and particularly relates to a purification device and a purification method for dimethyl carbonate. The purification device provided by the application can reduce the liquid droplets entrained in the evaporation gas in the evaporation device, control the impurities in the overhead product, and thus purify the overhead fraction, so that the metal ions in the raw material are effectively removed, the content of metal ions in the chemical product is significantly reduced, and the product quality is improved. The content of a single metal ion can be reduced to below 0.1 ppb, and the content of total metal ions can be reduced to below 1 ppb.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of separation and purification, and particularly relates to a purification device and application thereof and a dimethyl carbonate purification method. BACKGROUND

[0002] Electronic grade tetramethylammonium hydrogencarbonate is synthesized from trimethylamine, dimethyl carbonate in methanol solvent. The trimethylamine, dimethyl carbonate, methanol and the like required for the synthesis reaction need to be further rectified to reduce the 17 kinds of metal ions (Na, Ca, Fe and the like) in each to below 1 ppb. In some harsh application scenarios, the content of a single metal ion is even required to be reduced to below 0.1 ppp. However, in the rectification process of trimethylamine, dimethyl carbonate and methanol, the metal ions (especially Na, Fe and the like with higher content) can only be removed to 1-2 ppb, which is difficult to meet the use requirements of higher grade products.

[0003] Electronic chemicals have the characteristics of many varieties, high quality requirements, small amount, and harsh environmental cleanliness requirements, and these characteristics are becoming more and more obvious with the development of microfabrication technology. The separation and purification process is the key unit of electronic grade chemical production, and electronic grade chemicals are often obtained by purifying industrial grade chemicals. The purification process usually uses multiple separation technologies such as rectification, adsorption, crystallization, extraction, etc. in combination, among which the rectification technology has the outstanding advantages of high separation efficiency, high product purity, large treatment capacity, strong controllability, wide application range, and easy engineering, etc. It is a commonly used and key technology for the purification of electronic grade chemicals.

[0004] In recent years, with the rapid development of the semiconductor industry, the quality requirements of electronic grade chemicals are becoming higher and higher. Based on the characteristics of extremely high purity and strict impurity control, the rectification technology used in the preparation of electronic grade chemicals in the prior art cannot meet the higher use requirements of electronic grade chemicals. SUMMARY

[0005] Therefore, the technical problem to be solved by the present application is to overcome the defects in the prior art that the content of single metal ion and total metal ion is high after the separation and purification of industrial grade chemicals, and the higher use requirements cannot be met, so as to provide a purification device, application thereof and a dimethyl carbonate purification method.

[0006] To this end, the present application provides the following technical solutions:

[0007] According to one aspect of the present application, a purification device is provided, comprising:

[0008] The evaporation device is provided with a steam straight pipe at the top, the height of the steam straight pipe is 5-15 m, and the diameter of the steam straight pipe is 20-60 cm; for example, the height of the steam straight pipe is 5 m, 7 m, 9 m, 10 m, 12 m, 13 m, 15 m, or within the range of any of the above values; the diameter of the steam straight pipe can be 20 cm, 25 cm, 30 cm, 35 cm, 40 cm, 45 cm, 50 cm, 55 cm, 60 cm, or within the range of any of the above values;

[0009] The cyclone filter device is communicated with the evaporation device through the steam straight pipe, and the cyclone filter device comprises a cyclone separator and a precision filter assembly arranged in the cyclone separator.

[0010] In some optional embodiments, the height of the cyclone separator is 120-200 cm, and the diameter of the cyclone separator is 300-600 cm; for example, the height of the cyclone separator is 120 cm, 130 cm, 140 cm, 150 cm, 160 cm, 170 cm, 180 cm, 190 cm, 200 cm, or within the range of any of the above values; the diameter of the cyclone separator is 300 cm, 330 cm, 350 cm, 370 cm, 400 cm, 430 cm, 450 cm, 480 cm, 500 cm, 520 cm, 550 cm, 565 cm, 600 cm, or within the range of any of the above values.

[0011] In some optional embodiments, the length of the precision filter assembly is 80-100 cm.

[0012] And / or, the precision filter assembly comprises precision filter cartridges, and the number of cartridges is 20-40. Those skilled in the art can understand that the precision filter cartridge is a standard part in the field, and the diameter of the cartridge can be selected according to the specific application scenario (in this application, the diameter of the cartridge can be selected according to the diameter of the cyclone separator), for example, the commonly used cartridge diameter can be 10 inches, 20 inches, 30 inches, etc. For example, the length of the precision filter assembly is 80 cm, 85 cm, 90 cm, 95 cm, 100 cm, or within the range of any of the above values; the number of cartridges (i.e. the number of cartridges) is 20, 23, 25, 27, 30, 32, 35, 38, 40, or within the range of any of the above values.

[0013] In some optional embodiments, the filtering precision of the precision filter assembly is 0.1-1 μm. For example, the filtering precision of the precision filter assembly is 0.1 μm, 0.3 μm, 0.5 μm, 1 μm, or within the range of any of the above values.

[0014] In some alternative embodiments, the cyclone separator is made of 316L with a roughness Ra≤0.1 μm.

[0015] In some alternative embodiments, the precision filter is made of PP (Polypropylene), PTFE (Polytetrafluoroethylene) or PFA (Polyfluoroalkoxy).

[0016] In some alternative embodiments, the evaporation device comprises an evaporation kettle and a heating device capable of providing heat to the evaporation kettle, the evaporation kettle is provided with a raw material inlet and a kettle residue outlet at the bottom.

[0017] The cyclone filter device is provided with a material outlet at the top and a reflux pipe at the bottom, which communicates with the evaporation kettle.

[0018] According to another aspect of the present application, the above-mentioned purification device is used for the preparation of electronic chemicals.

[0019] According to another aspect of the present application, a purification method of dimethyl carbonate is provided, which uses the above-mentioned purification device.

[0020] In some alternative embodiments, the tower top pressure of the evaporation device is 0-2 PaG and the kettle temperature is 80-150℃. For example, the tower top pressure of the evaporation device is 0 PaG, 0.3 PaG, 0.5 PaG, 0.8 PaG, 1.0 PaG, 1.2 PaG, 1.5 PaG, 1.7 PaG, 2 PaG or within a range consisting of any of the above values; the kettle temperature is 80℃, 90℃, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃ or within a range consisting of any of the above values.

[0021] Alternatively, the tower top pressure of the evaporation device is 0-0.8 PaG and the kettle temperature is 90-130℃.

[0022] Alternatively, the gas flow rate of the cyclone separation device is 12-30 m / s and the material residence time is 0.2-10 s. For example, the gas flow rate of the cyclone separation device is 12 m / s, 15 m / s, 18 m / s, 20 m / s, 23 m / s, 25 m / s, 27 m / s, 30 m / s or within a range consisting of any of the above values; the material residence time is 0.2 s, 1 s, 1.5 s, 2 s, 3 s, 4 s, 5 s, 6 s, 7 s, 8 s, 9 s, 10 s or within a range consisting of any of the above values.

[0023] Those skilled in the art can understand that the precision filtering assembly described in the present application is a conventional device in the field, as long as it can achieve precision filtration and meet the requirement of filtration precision, the present application does not make specific limitation, as an example, it can be a precision filter cartridge. In the present application, the precision filtering assembly can be fixed in the cyclone separator by conventional method, as an example, the precision filter cartridge is fixed on the upper sealing plate of the cyclone separator, and is distributed in a lattice according to the number of cartridges.

[0024] Those skilled in the art can understand that the heating device described in the present application is a conventional device in the field, as long as it can provide heat for the evaporation kettle, the present application does not make specific limitation, as an example, it can be a heating jacket, a heating coil pipe, etc.

[0025] The technical scheme of the present application has the following advantages:

[0026] The purification device provided by the present application comprises: an evaporation device, a steam straight pipe is arranged at the top of the evaporation device, the height of the steam straight pipe is 5-15 m, and the diameter of the steam straight pipe is 20-60 cm; a cyclone filtering device is in communication with the evaporation device through the steam straight pipe, and the cyclone filtering device comprises a cyclone separator and a precision filtering assembly arranged in the cyclone separator. The purification device provided by the present application can reduce the liquid droplets entrained in the evaporation gas in the evaporation device, control the impurities in the product reaching the top of the tower, and thus purify the overhead fraction, thereby effectively removing the metal ions from the raw material, significantly reducing the content of metal ions in the chemical product, and improving the product quality. The content of a single metal ion can be reduced to below 0.1 ppb, and the content of total metal ions can be reduced to below 1 ppb. In addition, the present application couples the cyclone separator and the precision filtering assembly, uses the thrust of the external-to-center pressure drop of the cyclone separator to provide power for the steam filtration of the precision filtering assembly, saves power consumption, and reduces the operating pressure of the purification device, and further reduces the heating load of the evaporation device.

[0027] The purification device provided by the present application can control the metal impurities introduced in the process by controlling the material of the selected device unit, significantly reduce the metal ion pollution in the chemical product, and further improve the product quality.

[0028] The purification method of dimethyl carbonate provided by the application can effectively remove metal ions from raw materials by selecting the above purification device, significantly reduce the content of metal ions in dimethyl carbonate, and improve the product quality. Among the metal ions in industrial dimethyl carbonate, the content of Na and Fe ions is the highest. Taking these two metal ions as representatives, the purification device of the application can significantly reduce the content of Na and Fe ions and improve the product quality. The content of a single metal ion can be reduced to below 0.1 ppb, and the content of total metal ions can be reduced to below 1 ppb. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the specific embodiments of the application or the prior art, the drawings needed in the specific embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0030] Figure 1 is a structural schematic diagram of the purification device provided in the embodiments of the application;

[0031] Reference signs:

[0032] 1, raw material inlet; 2, steam straight pipe; 3, residue outlet; 4, heating device; 5, evaporation kettle; 6, cyclone separator; 7, precision filtration assembly; 8, material outlet; 9, reflux pipe. DETAILED DESCRIPTION

[0033] The following embodiments are provided to better further understand the application and are not limited to the best embodiments, and do not limit the content and protection scope of the application. Any person who obtains any product the same as or similar to the application under the inspiration of the application or by combining the application with other prior art features falls within the protection scope of the application.

[0034] The specific experimental steps or conditions not mentioned in the embodiments can be performed according to the conventional experimental steps described in the literature in the art or the operation or conditions. The reagents or instruments not mentioned by the manufacturer are conventional reagent products that can be obtained by market purchase.

[0035] In order to facilitate data comparison, the raw materials or crude dimethyl carbonate used in the following examples and comparative examples of the application are industrial-grade dimethyl carbonate produced by propylene carbonate or ethylene carbonate and methanol as raw materials (i.e. the raw material entering the purification device).

[0036] Example 1

[0037] The present embodiment provides a purification device, a structural schematic diagram of which is shown in Figure 1 as follows:

[0038] An evaporation device is provided with a steam straight pipe 2 at the top, the height of the steam straight pipe 2 is 5-15 m, and the diameter is 20-60 cm; the evaporation device includes an evaporation kettle 5 and a heating device 4 capable of providing heat for the evaporation kettle 5, the evaporation kettle 5 is provided with a raw material inlet 1 at the top and a kettle residue outlet 3 at the bottom; the heating device in the present embodiment is a heating jacket;

[0039] A cyclone filtering device is in communication with the evaporation device through the steam straight pipe 2, the cyclone filtering device includes a cyclone separator 6 and a precision filtering assembly 7 arranged inside the cyclone separator 6; the cyclone filtering device is provided with a material outlet 8 at the top and a reflux pipe 9 at the bottom, the reflux pipe 9 is in communication with the evaporation kettle 5; the height of the cyclone separator is 120-200 cm, and the diameter is 300-600 cm; the length of the precision filtering assembly is 80-100 cm, the number of cores is 20-40 cores in terms of 20-inch filter cores, the filtering precision of the precision filtering assembly is 0.1-1 μm, the material of the cyclone separator is 316L, and the roughness Ra is less than 0.1 μm; the material of the precision filtering assembly is PP, PTFE or PFA.

[0040] Embodiment 2

[0041] The present embodiment provides a purification method of dimethyl carbonate, which uses the purification device described in Embodiment 1, and the specific steps and operation parameters are as follows:

[0042] Industrial-grade dimethyl carbonate is provided into the evaporation kettle 5 through the raw material inlet 1, the heating jacket (heating device 4) is used to heat the evaporation kettle 5, the tower top pressure of the evaporation kettle is controlled to be 0 PaG, and the kettle temperature is controlled to be 90℃. The height of the steam straight pipe 2 of the evaporation kettle is 5 m, and the diameter is 20 cm.

[0043] The steam generated by the evaporation kettle 5 enters the cyclone filtering device through the steam straight pipe 2, and is further separated and filtered by the cyclone separator 6 and the precision filtering assembly 7 (in the present embodiment, it is a precision filter core, the same below). The height of the cyclone separator is 120 cm, and the diameter is 300 cm. The material of the cyclone separator is 316L, and the roughness Ra is 0.1 μm. The length of the precision filtering assembly is 80 cm, the number of cores is 20 in terms of 20-inch filter cores. The material of the precision filtering assembly is PP, the filtering precision of the precision filtering assembly is 0.1 μm. The gas flow rate of the cyclone separation device is 12 m / s, and the material residence time is 10 s. The dimethyl carbonate treated by the purification process is extracted through the material outlet 8. The condensed and settled reflux liquid in the purification process is refluxed to the evaporation kettle through the reflux pipe 9, the kettle residue liquid of the evaporation kettle is discharged through the kettle residue outlet 3, and the kettle residue discharge amount is 2% of the feed amount.

[0044] Example 3

[0045] The present example provides a method for purifying dimethyl carbonate, which uses the purification device described in Example 1, and the specific steps and operating parameters are as follows:

[0046] Industrial-grade dimethyl carbonate is provided to the evaporation kettle 5 through the raw material inlet 1, and the evaporation kettle 5 is heated using a heating jacket (heating device 4). The overhead pressure of the evaporation kettle is controlled at 0.8 PaG, and the kettle temperature is 130°C. The height of the vapor straight pipe 2 of the evaporation kettle is 15 m, and the diameter is 60 cm.

[0047] The vapor generated by the evaporation kettle 5 enters the cyclone filtration device through the vapor straight pipe 2, and is further separated and filtered by the cyclone separator 6 and the precision filtration assembly 7. The height of the cyclone separator is 200 cm, and the diameter is 600 cm. The material of the cyclone separator is 316L, and the roughness Ra is 0.1 μm. The length of the precision filtration assembly is 100 cm, and the number of 20-inch filter cartridges is 40. The material of the precision filtration assembly is PTFE, and the filtration precision of the precision filtration assembly is 1 μm. The purified dimethyl carbonate is extracted through the material outlet 8. The gas flow rate of the cyclone separation device is 30 m / s, and the material residence time is 0.2 s. The condensed and settled backflow liquid during the purification process is backflowed to the evaporation kettle through the backflow pipe 9, and the kettle residue is discharged through the kettle residue outlet 3. The kettle residue discharge amount is 1% of the feed amount.

[0048] Example 4

[0049] The present example provides a method for purifying dimethyl carbonate, which uses the purification device described in Example 1, and the specific steps and operating parameters are as follows:

[0050] Industrial-grade dimethyl carbonate is provided to the evaporation kettle 5 through the raw material inlet 1, and the evaporation kettle 5 is heated using a heating jacket (heating device 4). The overhead pressure of the evaporation kettle is controlled at 0.8 PaG, and the kettle temperature is 130°C. The height of the vapor straight pipe 2 of the evaporation kettle is 15 m, and the diameter is 60 cm.

[0051] The vapor generated by the evaporation kettle 5 enters the cyclone filter device through the vapor straight pipe 2, and is subjected to further separation and filtration treatment through the cyclone separator 6 and the precision filtration assembly 7, wherein the height of the cyclone separator is 160 cm, and the diameter is 450 cm. The material of the cyclone separator is 316L, and the roughness Ra is 0.1 μm. The length of the precision filtration assembly is 90 cm, the core number is 30, and the filter core is 20 inches. The material of the precision filtration assembly is PFA, the filtration precision of the precision filtration assembly is 1 μm, and the carbon dioxide generated by the evaporation kettle 5 enters the cyclone filter device through the vapor straight pipe 2. The purified dimethyl carbonate is taken out through the material outlet 8. The gas flow rate of the cyclone separation device is 22 m / s, and the material residence time is 5 s. The condensed and settled backflow liquid in the purification process is backflowed to the evaporation kettle through the backflow pipe 9, and the kettle residue is discharged through the kettle residue outlet 3. The kettle residue discharge amount is 1.5% of the feed amount.

[0052] Example 5

[0053] The present embodiment provides a purification method of dimethyl carbonate, which adopts the purification device of example 1, and the specific steps and operation parameters are as follows:

[0054] The industrial-grade dimethyl carbonate is provided to the evaporation kettle 5 through the raw material inlet 1, the evaporation kettle 5 is heated by the heating jacket (heating device 4), the tower top pressure of the evaporation kettle is controlled to be 0.2 PaG, and the kettle temperature is controlled to be 95 ℃. The height of the vapor straight pipe 2 of the evaporation kettle is 12 m, and the diameter is 30 cm.

[0055] The vapor generated by the evaporation kettle 5 enters the cyclone filter device through the vapor straight pipe 2, and is subjected to further separation and filtration treatment through the cyclone separator 6 and the precision filtration assembly 7, wherein the height of the cyclone separator is 180 cm, and the diameter is 550 cm. The material of the cyclone separator is 316L, and the roughness Ra is 0.1 μm. The length of the precision filtration assembly is 85 cm, the core number is 35, and the filter core is 20 inches. The material of the precision filtration assembly is PFA, the filtration precision of the precision filtration assembly is 0.1 μm, and the carbon dioxide generated by the evaporation kettle 5 enters the cyclone filter device through the vapor straight pipe 2. The purified dimethyl carbonate is taken out through the material outlet 8. The gas flow rate of the cyclone separation device is 18 m / s, and the material residence time is 8 s. The condensed and settled backflow liquid in the purification process is backflowed to the evaporation kettle through the backflow pipe 9, and the kettle residue is discharged through the kettle residue outlet 3. The kettle residue discharge amount is 1% of the feed amount.

[0056] Example 6

[0057] The present embodiment provides a purification method of dimethyl carbonate, which adopts the purification device of example 1, and the specific steps and operation parameters are as follows:

[0058] The industrial grade dimethyl carbonate is provided to the evaporation kettle 5 through the raw material inlet 1, the evaporation kettle 5 is heated by the heating jacket (heating device 4), the overhead pressure of the evaporation kettle is controlled to be 0.6 PaG, and the kettle temperature is 120°C. The height of the steam straight pipe 2 of the evaporation kettle is 7 m, and the diameter is 50 cm.

[0059] The steam generated by the evaporation kettle 5 enters the cyclone filtering device through the steam straight pipe 2, and is further separated and filtered by the cyclone separator 6 and the precision filtering assembly 7, wherein the height of the cyclone separator is 130 cm, and the diameter is 350 cm. The material of the cyclone separator is 316L, and the roughness Ra is 0.1 μm. The length of the precision filtering assembly is 95 cm, the filter core is 20 inches, the core number is 25, the material of the precision filtering assembly is PP, and the filtering precision of the precision filtering assembly is 1 μm. The purified dimethyl carbonate is taken out through the material outlet 8. The gas flow rate of the cyclone separation device is 26 m / s, and the material residence time is 4 s. The condensed and settled backflow liquid in the purification process is backflowed to the evaporation kettle through the backflow pipe 9, the kettle residue of the evaporation kettle is discharged through the kettle residue outlet 3, and the kettle residue discharge amount is 2% of the feed amount.

[0060] Comparative Example 1

[0061] The comparative example provides a purification method of dimethyl carbonate, and only the evaporation device is used for purification treatment compared with Example 2, and the specific steps are as follows:

[0062] The industrial grade dimethyl carbonate is provided to the evaporation kettle 5 through the raw material inlet 1, the evaporation kettle 5 is heated by the heating jacket, the overhead pressure of the evaporation kettle is controlled to be 0 PaG, and the kettle temperature is 90°C. The height of the steam straight pipe 2 of the evaporation kettle is 5 m, and the diameter is 20 cm. The purified dimethyl carbonate is taken out from the end of the steam straight pipe 2.

[0063] Comparative Example 2

[0064] The comparative example provides a purification method of dimethyl carbonate, and the only difference compared with Example 2 is that the precision filtering assembly is not arranged in the cyclone filtering device.

[0065] Comparative Example 3

[0066] The comparative example provides a purification method of dimethyl carbonate, and the only difference compared with Example 2 is that the precision filtering assembly is used instead of the cyclone filtering device, that is, the steam generated by the evaporation kettle enters the precision filtering assembly through the steam straight pipe.

[0067] Comparative Example 4

[0068] The comparative example provides a purification method of dimethyl carbonate, and the only difference compared with Example 2 is that the height of the evaporation straight pipe is 3 m, and the diameter is 10 cm.

[0069] Test Example

[0070] The dimethyl carbonate products obtained by the method of each example and the comparative example were detected according to the national standard GB / T 33107-2016 dimethyl carbonate for industrial use, the particle number and the metal ion content were detected according to GB / T 37403-2019, and the results are shown in the following table.

[0071] Table 1

[0072]

[0073]

[0074] From the data in the above table, by using the purification device provided in the present application, through the combination of gravity settling in the steam straight pipe of a specific size, cyclone separation and precision filtration of the cyclone filtration device, the liquid droplets entrained in the evaporation gas process in the evaporation device can be reduced, the impurities reaching the top product can be controlled, thereby achieving the purpose of purifying the top fraction, and then effectively removing the metal ions from the raw material, significantly reducing the metal ion content in the dimethyl carbonate, and improving the product quality. Among them, the content of a single metal ion can be reduced to below 0.1 ppb.

[0075] Obviously, the above examples are only examples for clarity and do not limit the embodiments. Based on the above description, those skilled in the art can also make other different forms of changes or variations. Here, it is not necessary and impossible to exhaust all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A purification device, characterized in that, The application relates to a purification device for industrial-grade chemicals and preparation of electronic chemicals. The purification device comprises an evaporation device provided with a steam straight pipe with a height of 5-15 m and a diameter of 20-60 cm; a cyclone filtering device in communication with the evaporation device through the steam straight pipe, wherein the cyclone filtering device comprises a cyclone separator and a precision filtering assembly arranged in the cyclone separator; the cyclone separator has a height of 120-200 cm and a diameter of 300-600 cm; the precision filtering assembly has a length of 80-100 cm; the precision filtering assembly comprises precision filter cartridges, and the number of the cartridges is 20-40; and the precision filtering assembly has a filtering precision of 0.1-1 mu m. The cyclone separator is made of 316L, and has a roughness Ra of less than or equal to 0.1 mu m. The precision filtering assembly is made of polypropylene, polytetrafluoroethylene or tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer. The evaporation device comprises an evaporation kettle and a heating device capable of providing heat for the evaporation kettle, the evaporation kettle is provided with a raw material inlet and a kettle residue outlet at the bottom, and the cyclone filtering device is provided with a material outlet at the top and a reflux pipe at the bottom, wherein the reflux pipe is in communication with the evaporation kettle.

5. Application of the purification device according to any one of claims 1-4 to the purification of industrial-grade chemicals and preparation of electronic chemicals. The purification device according to any one of claims 1-4 is adopted.

2. The purification device of claim 1, wherein, The tower top pressure of the evaporation device is 0-2 PaG, and the kettle temperature is 80-150 DEG C.

3. The purification device of claim 1, wherein, The gas flow rate of the cyclone filtering device is 12-30 m / s, and the material residence time is 0.2-10 s.

4. The purification device according to any one of claims 1 to 3, characterized in that, The tower top pressure of the evaporation device is 0-0.8 PaG, and the kettle temperature is 90-130 DEG C. ​ ​ 6. A method for purifying dimethyl carbonate, characterized by, ​ 7. The purification method of dimethyl carbonate according to claim 6, characterized by, ​ ​ 8. The purification method of dimethyl carbonate according to claim 7, characterized by, ​

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