Purification device, application thereof and dimethyl carbonate purification method

Abstract

The invention belongs to the technical field of separation and purification, and particularly relates to a dimethyl carbonate purification device and a dimethyl carbonate purification method. According to the purification device provided by the invention, by combining gravity settling in the steam straight pipe with a specific size and cyclone separation and precision filtration of the cyclone filtration device, liquid drops entrained in the evaporation device in a gas evaporation process can be reduced, and impurities reaching a tower top product can be controlled, so that the purpose of purifying tower top fractions is achieved; the metal ions in the raw materials are effectively removed, the content of the metal ions in chemicals is remarkably reduced, the product quality is improved, the content of single metal ions can be reduced to 0.1 ppb or below, and the content of total metal ions can be reduced to 1ppb or below.

Description

Technical Field

[0001] The present application belongs to the technical field of separation and purification, and specifically relates to a purification device and its application and a dimethyl carbonate purification method. Background Art

[0002] Electronic grade tetramethylammonium bicarbonate is synthesized from trimethylamine and dimethyl carbonate in methanol solvent. The trimethylamine, dimethyl carbonate, methanol, etc. required for this synthesis reaction need to be further distilled to reduce the 17 metal ions (Na, Ca, Fe, etc.) to less than 1 ppb. In some demanding application scenarios, the content of a single metal ion is even required to be reduced to less than 0.1 ppp. However, in the distillation process of trimethylamine, dimethyl carbonate, and methanol, the metal ions (especially those with high content such as Na and Fe) can often 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 a wide variety, high quality requirements, small dosage, and strict requirements on environmental cleanliness. These characteristics are becoming more and more obvious with the development of micro-processing technology. The separation and purification process is a key unit in the production of electronic-grade chemicals, and electronic-grade chemicals are often purified from industrial-grade chemicals. The purification process usually uses a variety of separation technologies such as distillation, adsorption, crystallization, and extraction. Among them, distillation technology has outstanding advantages such as high separation efficiency, high product purity, large processing capacity, strong controllability, wide application range, and easy engineering. It is a common technology 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 for electronic-grade chemicals have become increasingly higher. Due to the characteristics of extremely high purity and strict impurity control, the distillation technology used in the preparation of electronic-grade chemicals in existing technologies cannot meet the higher usage requirements of electronic-grade chemicals. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present application is to overcome the defects of the prior art in that the single metal ion content and the total metal ion content of industrial-grade chemicals after separation and purification are high and cannot meet higher usage requirements, thereby providing a purification device and its application and a dimethyl carbonate purification method.

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

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

[0008] An evaporation device, with a straight steam pipe on the top, the height of the straight steam pipe is 5 to 15 m, and the diameter is 20 to 60 cm; as an example, the height of the straight steam 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 straight steam 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 connected to the evaporation device through the steam straight pipe, and the cyclone filter device includes a cyclone separator and a precision filter component arranged inside the cyclone separator.

[0010] In some optional embodiments, the height of the cyclone separator is 120-200 cm, and the diameter is 300-600 cm. As an 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 filtration component is 80 to 100 cm;

[0012] And / or, the precision filtration component includes a precision filter element, and the number of cores is 20 to 40. It can be understood by those skilled in the art that the precision filter element is a standard part in the field, and the diameter size of the filter element can be selected according to the specific application scenario (in this application, it can be selected according to the diameter of the cyclone separator). For example, the commonly used filter element diameter size can be 10 inches, 20 inches, 30 inches, etc. As an example, the length of the precision filtration component is 80cm, 85cm, 90cm, 95cm, 100cm, or within the range of any of the above values; the number of cores (i.e., the number of filter elements) 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 filtration accuracy of the precision filtration component is 0.1-1 μm. As an example, the filtration accuracy of the precision filtration component 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 optional embodiments, the cyclone separator is made of 316L with a roughness Ra≤0.1 μm.

[0015] In some optional embodiments, the material of the precision filtration component is PP (polypropylene), PTFE (polytetrafluoroethylene) or PFA (tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer, Polyfluoroalkoxy).

[0016] In some optional embodiments, the evaporation device includes an evaporation kettle and a heating device capable of providing heat therefor, the evaporation kettle is provided with a raw material inlet on the top and a kettle residue outlet at the bottom;

[0017] The top of the cyclone filter device is provided with a material outlet, and the bottom is provided with a reflux pipe, and the reflux pipe is communicated with the evaporator.

[0018] According to another aspect of the present application, there is provided an application of the above-mentioned purification device in purifying industrial-grade chemicals to prepare electronic chemicals.

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

[0020] In some optional embodiments, the tower top pressure of the evaporation device is 0-2PaG, and the tower bottom temperature is 80-150°C; as an example, the tower top pressure of the evaporation device is 0PaG, 0.3PaG, 0.5PaG, 0.8PaG, 1.0PaG, 1.2PaG, 1.5PaG, 1.7PaG, 2PaG, or within the range of any of the above values; the tower bottom temperature is 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, or within the range of any of the above values;

[0021] Optionally, the tower top pressure of the evaporation device is 0-0.8 PaG, and the tower bottom temperature is 90-130°C;

[0022] And / or, the gas flow rate of the cyclone separation device is 12-30 m / s, and the material residence time is 0.2-10 s. As an 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 the range 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 the range of any of the above values.

[0023] It can be understood by those skilled in the art that the precision filtration assembly described in this application is a conventional device in the field. As long as it can achieve precision filtration and meet the requirements of filtration accuracy, this application does not make specific limitations. As an example, it can be a precision filter element. In this application, the precision filtration assembly can be fixed in the cyclone separator by conventional methods. As an example, the precision filter element is fixed on the upper cover plate of the cyclone separator and is distributed in a lattice according to the number of filter elements.

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

[0025] The technical solution of this application has the following advantages:

[0026] The purification device provided by the present application includes: an evaporation device, a steam straight pipe is arranged on the top, the height of the steam straight pipe is 5 to 15m, and the diameter is 20 to 60cm; a cyclone filter device is connected to the evaporation device through the steam straight pipe, and the cyclone filter device includes a cyclone separator and a precision filter component arranged inside it. The purification device provided by the present application can reduce the droplets entrained in the evaporation gas process in the evaporation device by combining the gravity sedimentation in the steam straight pipe of a specific size, and the cyclone separation and precision filtration of the cyclone filter device, so as to control the impurities reaching the top product of the tower, thereby achieving the purpose of purifying the top fraction of the tower, and then effectively removing the metal ions of the raw materials, significantly reducing the metal ion content in the chemicals, and improving the product quality, wherein the content of a single metal ion can be reduced to less than 0.1ppb, and the content of total metal ions can be reduced to less than 1ppb. In addition, the present application couples the cyclone separator and the precision filter component, and utilizes the thrust of the pressure drop from the outside of the cyclone separator to the center to provide the precision filter component with steam filtration power, saving power consumption, and reducing the operating pressure of the purification device, further reducing the heating load of the evaporation device.

[0027] The purification device provided in the present application controls the material of the selected device units and the metal impurities introduced during the process, thereby significantly reducing the metal ion contamination in chemicals and further improving the product quality.

[0028] The purification method of dimethyl carbonate provided by the present application effectively removes the metal ions of the raw materials by selecting the above-mentioned purification device provided by the present application, significantly reduces the metal ion content in dimethyl carbonate, and improves 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, it has been tested that the purification device of the present application can significantly reduce the content of Na ions and Fe ions, improve the product quality, wherein 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 THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 It is a schematic diagram of the structure of the purification device provided in the examples of the present application;

[0031] Reference numerals:

[0032] 1. Raw material inlet; 2. Steam straight pipe; 3. Kettle residue outlet; 4. Heating device; 5. Evaporator; 6. Cyclone separator; 7. Precision filtration component; 8. Material outlet; 9. Reflux pipe. DETAILED DESCRIPTION

[0033] The following examples are provided for a better understanding of the present application, but are not limited to the best implementation mode described, and do not limit the content and protection scope of the present application. Any product identical or similar to the present application obtained by anyone under the inspiration of the present application or by combining the features of the present application with other prior arts shall fall within the protection scope of the present application.

[0034] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0035] For the convenience of data comparison, the raw material or crude dimethyl carbonate used in the following examples and comparative examples of the present application is industrial-grade dimethyl carbonate produced from propylene carbonate or ethylene carbonate and methanol as raw materials (i.e., the raw material entering the purification device).

[0036] Example 1

[0037] This embodiment provides a purification device, and its structural schematic diagram is as follows Figure 1 As shown, including:

[0038] The evaporation device is provided with a steam straight pipe 2 at the top, the height of the steam straight pipe 2 is 5 to 15 meters, and the diameter is 20 to 60 cm; the evaporation device comprises an evaporation kettle 5 and a heating device 4 capable of providing heat therefor, the evaporation kettle 5 is provided with a raw material inlet 1, and the bottom is provided with a kettle residue outlet 3; the heating device in this embodiment is a heating jacket;

[0039] The cyclone filter device is connected to the evaporation device through the steam straight pipe 2, and the cyclone filter device includes a cyclone separator 6 and a precision filter component 7 arranged inside the cyclone filter device; a material outlet 8 is arranged on the top of the cyclone filter device, and a reflux pipe 9 is arranged on the bottom, and the reflux pipe 9 is connected to the evaporation kettle 5; the height of the cyclone separator is 120 to 200 cm, and the diameter is 300 to 600 cm; the length of the precision filter component is 80 to 100 cm, and the number of cores is 20 to 40 based on a 20-inch filter element. The filtration accuracy of the precision filter component is 0.1 to 1 μm, and the material of the cyclone separator is 316L, and the roughness Ra<0.1 μm; the material of the precision filter component is PP, PTFE or PFA.

[0040] Example 2

[0041] This embodiment provides a method for purifying dimethyl carbonate, using the purification device described in Example 1, and the specific steps and operating parameters are as follows:

[0042] Industrial-grade dimethyl carbonate is provided to the evaporator 5 through the raw material inlet 1, and the evaporator 5 is heated by a heating jacket (heating device 4), and the top pressure of the evaporator is controlled to be 0 PaG and the temperature of the tower is controlled to be 90° C. The steam straight pipe 2 of the evaporator has a height of 5 m and a diameter of 20 cm.

[0043] The steam generated by the evaporator 5 enters the cyclone filter device through the steam straight pipe 2, and is further separated and filtered through the cyclone separator 6 and the precision filter component 7 (precision filter element in this embodiment, the same below), wherein the height of the cyclone separator is 120cm and the diameter is 300cm. The cyclone separator is made of 316L with a roughness of Ra=0.1μm. The length of the precision filter component is 80cm, and the number of cores is 20 based on a 20-inch filter element. The material of the precision filter component is PP, and the filtration accuracy of the precision filter component is 0.1μm. The gas flow rate of the cyclone separation device is 12m / s, and the material residence time is 10s. The purified dimethyl carbonate is extracted through the material outlet 8. The condensed and precipitated reflux liquid during the purification process is refluxed to the evaporator through the reflux pipe 9, and the residual liquid of the evaporator is discharged through the residual outlet 3, and the residual discharge amount is 2% of the feed amount.

[0044] Example 3

[0045] This embodiment provides a method for purifying dimethyl carbonate, using 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 evaporator 5 through the raw material inlet 1, and the evaporator 5 is heated by a heating jacket (heating device 4), and the top pressure of the evaporator is controlled to be 0.8 PaG and the bottom temperature is controlled to be 130° C. The steam straight pipe 2 of the evaporator has a height of 15 m and a diameter of 60 cm.

[0047] The steam generated by the evaporator 5 enters the cyclone filter device through the steam straight pipe 2, and is further separated and filtered through the cyclone separator 6 and the precision filter component 7, wherein the height of the cyclone separator is 200 cm and the diameter is 600 cm. The cyclone separator is made of 316L with a roughness of Ra = 0.1 μm. The length of the precision filter component is 100 cm, and the number of cores is 40 based on a 20-inch filter element. The material of the precision filter component is PTFE, and the filtration accuracy of the precision filter component is 1 μm. The purified dimethyl carbonate is extracted through the material outlet 8. The gas flow rate of the cyclone separator is 30 m / s, and the material residence time is 0.2 s. The condensed and precipitated reflux liquid during the purification process is refluxed to the evaporator through the reflux pipe 9, and the residual liquid of the evaporator is discharged through the residual outlet 3, and the residual discharge amount is 1% of the feed amount.

[0048] Example 4

[0049] This embodiment provides a method for purifying dimethyl carbonate, using 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 evaporator 5 through the raw material inlet 1, and the evaporator 5 is heated by a heating jacket (heating device 4), and the top pressure of the evaporator is controlled to be 0.4 PaG and the bottom temperature is controlled to be 110° C. The steam straight pipe 2 of the evaporator has a height of 10 m and a diameter of 40 cm.

[0051] The steam generated by the evaporator 5 enters the cyclone filter device through the steam straight pipe 2, and is further separated and filtered through the cyclone separator 6 and the precision filter component 7, wherein the height of the cyclone separator is 160cm and the diameter is 450cm. The cyclone separator is made of 316L with a roughness of Ra=0.1μm. The length of the precision filter component is 90cm, and the number of cores is 30 based on a 20-inch filter element. The material of the precision filter component is PFA, and the filtration accuracy of the precision filter component is 1μm. The purified dimethyl carbonate is extracted through the material outlet 8. The gas flow rate of the cyclone separator is 22m / s, and the material residence time is 5s. The condensed and precipitated reflux liquid in the purification process is refluxed to the evaporator through the reflux pipe 9, and the residual liquid of the evaporator is discharged through the residual outlet 3, and the residual discharge amount is 1.5% of the feed amount.

[0052] Example 5

[0053] This embodiment provides a method for purifying dimethyl carbonate, using the purification device described in Example 1, and the specific steps and operating parameters are as follows:

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

[0055] The steam generated by the evaporator 5 enters the cyclone filter device through the steam straight pipe 2, and is further separated and filtered through the cyclone separator 6 and the precision filter component 7, wherein the height of the cyclone separator is 180 cm and the diameter is 550 cm. The cyclone separator is made of 316L with a roughness of Ra = 0.1 μm. The length of the precision filter component is 85 cm, and the number of cores is 35 based on a 20-inch filter element. The material of the precision filter component is PFA, and the filtration accuracy of the precision filter component is 0.1 μm. The purified dimethyl carbonate is extracted through the material outlet 8. The gas flow rate of the cyclone separator is 18 m / s, and the material residence time is 8 s. The condensed and precipitated reflux liquid during the purification process is refluxed to the evaporator through the reflux pipe 9, and the residual liquid of the evaporator is discharged through the residual outlet 3, and the residual discharge amount is 1% of the feed amount.

[0056] Example 6

[0057] This embodiment provides a method for purifying dimethyl carbonate, using the purification device described in Example 1, and the specific steps and operating parameters are as follows:

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

[0059] The steam generated by the evaporator 5 enters the cyclone filter device through the steam straight pipe 2, and is further separated and filtered through the cyclone separator 6 and the precision filter component 7, wherein the height of the cyclone separator is 130 cm and the diameter is 350 cm. The cyclone separator is made of 316L with a roughness of Ra = 0.1 μm. The length of the precision filter component is 95 cm, and the number of cores is 25 based on a 20-inch filter element. The material of the precision filter component is PP, and the filtration accuracy of the precision filter component is 1 μm. The purified dimethyl carbonate is extracted through the material outlet 8. The gas flow rate of the cyclone separator is 26 m / s, and the material residence time is 4 s. The condensed and precipitated reflux liquid during the purification process flows back to the evaporator through the reflux pipe 9, and the residual liquid of the evaporator is discharged through the residual outlet 3, and the residual discharge amount is 2% of the feed amount.

[0060] Comparative Example 1

[0061] This comparative example provides a method for purifying dimethyl carbonate. Compared with Example 2, only an evaporation device is used for purification. The specific steps are as follows:

[0062] Industrial-grade dimethyl carbonate is provided to the evaporator 5 through the raw material inlet 1, and the evaporator 5 is heated by a heating jacket, and the top pressure of the evaporator is controlled to be 0 PaG and the bottom temperature is controlled to be 90° C. The steam straight pipe 2 of the evaporator has a height of 5 m and a diameter of 20 cm, and the purified dimethyl carbonate is extracted from the end of the steam straight pipe 2.

[0063] Comparative Example 2

[0064] This comparative example provides a method for purifying dimethyl carbonate. Compared with Example 2, the only difference is that no precision filtration component is provided in the cyclone filtration device.

[0065] Comparative Example 3

[0066] This comparative example provides a method for purifying dimethyl carbonate. Compared with Example 2, the only difference is that a precision filtration component is used instead of a cyclone filter device, that is, the steam generated by the evaporator enters the precision filtration component through a steam straight pipe.

[0067] Comparative Example 4

[0068] This comparative example provides a method for purifying dimethyl carbonate. Compared with Example 2, the only difference is that the height of the evaporation straight tube is 3 m and the diameter is 10 cm.

[0069] Test Case

[0070] Referring to the national standard GB / T 33107-2016 Industrial Dimethyl Carbonate, industrial-grade dimethyl carbonate and dimethyl carbonate products produced by the methods of various embodiments and comparative examples were tested, and the number of particles and metal ion content were tested according to GB / T37403-2019. The results are shown in the following table.

[0071] Table 1

[0072]

[0073]

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

[0075] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the invention.

Claims

1. A purification device, characterized in that: include: The evaporation device has a steam straight pipe on the top, the height of the steam straight pipe is 5 to 15 meters and the diameter is 20 to 60 cm; The cyclone filter device is connected to the evaporation device through the steam straight pipe, and the cyclone filter device includes a cyclone separator and a precision filter component arranged inside the cyclone separator.

2. The purification device according to claim 1, characterized in that: The cyclone separator has a height of 120 to 200 cm and a diameter of 300 to 600 cm.

3. The purification device according to claim 1, characterized in that: The length of the precision filtration component is 80 to 100 cm; And / or, the precision filtration component includes precision filter elements with 20 to 40 elements.

4. The purification device according to claim 1, characterized in that: The filtration accuracy of the precision filtration component is 0.1-1 μm.

5. The purification device according to any one of claims 1 to 4, characterized in that: The cyclone separator is made of 316L material with a roughness Ra≤0.1 μm.

6. The purification device according to any one of claims 1 to 4, characterized in that: The material of the precision filtering component is polypropylene, polytetrafluoroethylene or tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer.

7. The purification device according to any one of claims 1 to 4, characterized in that: The evaporation device comprises an evaporation kettle and a heating device capable of providing heat therefor, wherein the evaporation kettle is provided with a raw material inlet and a kettle residue outlet at the bottom; The top of the cyclone filter device is provided with a material outlet, and the bottom is provided with a reflux pipe, and the reflux pipe is communicated with the evaporator.

8. Use of the purification device according to any one of claims 1 to 7 in purifying industrial-grade chemicals to prepare electronic chemicals.

9. A method for purifying dimethyl carbonate, characterized in that: A purification device according to any one of claims 1 to 7 is used.

10. The method for purifying dimethyl carbonate according to claim 9, characterized in that: The tower top pressure of the evaporation device is 0-2 PaG, and the tower bottom temperature is 80-150°C; Optionally, the tower top pressure of the evaporation device is 0-0.8 PaG, and the tower bottom temperature is 90-130°C; And / or, the gas flow rate of the cyclone separation device is 12 to 30 m / s, and the material residence time is 0.2 to 10 s.

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