A purification system for boron trifluoride gas

Abstract

The present invention relates to a purification system for boron trifluoride gas. The purification system for boron trifluoride gas comprises an anhydrous hydrogen fluoride storage tank, a condenser, an adsorbent storage tank and a filter which are connected in sequence through pipelines. The present invention adopts the methods of absorption by the anhydrous hydrogen fluoride storage tank and adsorption by the adsorbent storage tank. Metal components in the boron trifluoride gas are first dissolved in the anhydrous hydrogen fluoride liquid or form new compounds with gaseous hydrogen fluoride and then are adsorbed on metal fluorides, so as to be removed together with hydrogen fluoride. The purification system for boron trifluoride gas of the present invention has the characteristics of short process flow and low energy consumption.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical purification, and particularly to a purification system for boron trifluoride gas. Background Art

[0002] Boron trifluoride (BF3) is an important raw material widely used in organic chemical industry. It is used as an acidic catalyst in many organic chemical reactions such as esterification, alkylation, polymerization, isomerization, sulfonation, and nitration reactions, and is also used to prepare boron halides, elemental boron, boranes, borohydrides and other borides.

[0003] Existing purification techniques for boron trifluoride gas mostly adopt adsorption method, cold trap method, low-temperature rectification method or a combination of the above methods. The impurity components in the gas are removed by the adsorption of the adsorbent or the boiling point differences between different gas components. When the content of boron trifluoride gas and the impurities contained therein is very low, it is difficult to efficiently adsorb the impurities using the adsorption method; when the boiling point and melting point differences between boron trifluoride gas and the impurities contained therein are very small, the removal effect is not good when using the cold trap method and the low-temperature rectification method.

[0004] The content of metal impurities in boron trifluoride gas is relatively low, and they generally exist in the gas in the form of fine particles of metals or metal compounds, making it difficult to remove them using a single adsorption method. Or metal halides and metal complex gases with relatively high vapor pressures are easy to sublimate, and it is not easy to remove them using low-temperature purification methods. Summary of the Invention

[0005] Based on this, it is necessary to provide a purification system that can effectively remove metal impurities in boron trifluoride gas.

[0006] To achieve the above object, the present invention provides a technical solution:

[0007] A purification system for boron trifluoride gas, characterized in that the purification system for boron trifluoride gas includes:

[0008] An anhydrous hydrogen fluoride storage tank; the anhydrous hydrogen fluoride storage tank is provided with a first inlet and a first outlet, and a gas-liquid mixer is arranged in the anhydrous hydrogen fluoride storage tank, and the gas-liquid mixer is connected to the first inlet;

[0009] A condenser; the anhydrous hydrogen fluoride storage tank is provided with a second inlet and a second outlet, and the second inlet is connected to the first outlet;

[0010] An adsorbent storage tank; the adsorbent storage tank is provided with a third inlet and a third outlet, and the third inlet is connected to the second outlet;

[0011] A filter; the filter includes a fourth inlet and a fourth outlet, and the fourth inlet is connected to the third outlet;

[0012] The adsorbent in the adsorbent storage tank includes metal fluoride.

[0013] Preferably, the purification system of boron trifluoride gas further includes a cooling jacket, which is sleeved outside the anhydrous hydrogen fluoride storage tank.

[0014] Preferably, the cooling jacket is provided with a first thermometer.

[0015] Preferably, a flow meter and a regulating valve are provided on the pipeline of the first inlet.

[0016] Preferably, the anhydrous hydrogen fluoride storage tank is provided with a liquid level gauge.

[0017] Preferably, the second outlet is provided with a second thermometer.

[0018] Preferably, the third inlet is provided with a first pressure transmitter, and the fourth inlet is provided with a second pressure transmitter.

[0019] Preferably, the adsorbent storage tank is provided with a temperature transmitter.

[0020] Preferably, the fourth inlet is provided with a third pressure transmitter, and the fourth outlet is provided with a fourth pressure transmitter.

[0021] Preferably, the filter is a high-precision filter.

[0022] Advantages of the present invention:

[0023] The present invention adopts the method of absorption by the anhydrous hydrogen fluoride storage tank and adsorption by the adsorbent storage tank. The metal components in the boron trifluoride gas are first dissolved in the anhydrous hydrogen fluoride liquid or form new compounds with gaseous hydrogen fluoride, and then adsorbed on the metal fluoride, so as to be removed together with hydrogen fluoride.

[0024] The purification system of boron trifluoride gas of the present invention has the characteristics of short process and low energy consumption. Description of the drawings

[0025] Figure 1 It is a flow chart of the purification system of boron trifluoride gas.

[0026] In the figure, 100 is an anhydrous hydrogen fluoride storage tank; 110 is the first inlet; 120 is the first outlet; 130 is a gas-liquid mixer; 140 is a flow meter; 150 is a regulating valve; 160 is a liquid level gauge; 200 is a condenser; 210 is the second inlet; 220 is the second outlet; 230 is the second thermometer; 300 is an adsorbent storage tank; 310 is the third inlet; 320 is the third outlet; 330 is the first pressure transmitter; 340 is the second pressure transmitter; 400 is a filter; 410 is the fourth inlet; 420 is the fourth outlet; 430 is the third pressure transmitter; 440 is the fourth pressure transmitter; 500 is a cooling jacket; 510 is the first thermometer; 600 is a liquid phase reflux pipeline. Detailed implementation manners

[0027] In order to better illustrate the purpose, technical solution and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0028] In the embodiments, unless otherwise specified, the test methods used are all conventional methods, and the materials, reagents, etc. used, unless otherwise specified, can all be obtained from commercial channels.

[0029] A purification system for boron trifluoride gas, as Figure 1 shown, the purification system for boron trifluoride gas includes an anhydrous hydrogen fluoride storage tank 100, a condenser 200, an adsorbent storage tank 300 and a filter 400 that are sequentially connected through pipelines.

[0030] The anhydrous hydrogen fluoride storage tank 100 is provided with a first inlet 110 and a first outlet 120. A gas-liquid mixer 130 is arranged in the anhydrous hydrogen fluoride storage tank 100, and the gas-liquid mixer 130 is connected to the first inlet 110; the anhydrous hydrogen fluoride storage tank 100 is provided with a second inlet 210 and a second outlet 220, and the second inlet 210 is connected to the first outlet 120; the adsorbent storage tank 300 is provided with a third inlet 310 and a third outlet 320, and the third inlet 310 is connected to the second outlet 220; the filter 400 includes a fourth inlet 410 and a fourth outlet 420, and the fourth inlet 410 is connected to the third outlet 320.

[0031] The purification system for boron trifluoride gas further includes a liquid phase reflux pipeline 600, and the liquid phase reflux pipeline 600 is connected to the condenser 200 and the anhydrous hydrogen fluoride storage tank 100.

[0032] Specifically, the purification system for boron trifluoride gas further includes a cooling jacket 500. The cooling jacket 500 is sleeved outside the anhydrous hydrogen fluoride storage tank 100. The cooling jacket 500 is provided with a first thermometer 510 for controlling the temperature of the anhydrous hydrogen fluoride storage tank 100 and regulating the cold quantity supply of the anhydrous hydrogen fluoride storage tank 100.

[0033] A flow meter 140 and a regulating valve 150 are provided on the pipeline of the first inlet 110 to control the flow rate of boron trifluoride gas.

[0034] The anhydrous hydrogen fluoride storage tank 100 is equipped with a liquid level gauge 160 to monitor the liquid level of the anhydrous hydrogen fluoride storage tank 100.

[0035] The second outlet 220 is provided with a second thermometer 230 to monitor the outlet temperature of the condenser 200 and control the load of the condenser 200.

[0036] The third inlet 310 is provided with a first pressure transmitter 330, and the fourth inlet 410 is provided with a second pressure transmitter 340 to monitor the pressure difference between the inlet and outlet of the adsorption tank.

[0037] The adsorbent storage tank 300 is provided with a temperature transmitter to monitor the temperature change of the adsorbent storage tank 300.

[0038] The fourth inlet 410 is provided with a third pressure transmitter 430, and the fourth outlet 420 is provided with a fourth pressure transmitter 440 to monitor the pressure difference between the fourth inlet 410 and the fourth outlet 420 of the filter 400.

[0039] The adsorbent in the adsorbent storage tank 300 includes metal fluorides, specifically at least one of KF, NaF, and MgF2.

[0040] In one embodiment, the filter 400 is a high-precision filter, and one side of the high-precision filter is connected to the boron trifluoride gas outlet pipeline through a fan.

[0041] Specifically, the filler of the high-precision filter is PTFE (polytetrafluoroethylene), and the pore diameter of the filter membrane of the high-precision filter is 0.03 - 5.0 μm.

[0042] The specific purification process of boron trifluoride gas is as follows:

[0043] The unpurified boron trifluoride gas enters the anhydrous hydrogen fluoride storage tank 100 under the action of the cylinder pressure, and is fully mixed with the anhydrous hydrogen fluoride solution through the gas-liquid mixer 130 in the tank.

[0044] The mixed gas is led out through the pipeline of the first outlet 120 at the top of the anhydrous hydrogen fluoride storage tank 100 to the condenser 200. After the condenser 200 cools part of the hydrogen fluoride gas to the liquid state, it returns to the anhydrous hydrogen fluoride storage tank 100 through the liquid phase reflux pipeline 600, and the remaining boron trifluoride and the uncompletely cooled hydrogen fluoride mixed gas enter the adsorption agent storage tank 300.

[0045] After being fully absorbed by the adsorbent storage tank 300, the boron trifluoride gas is then passed through the filter 400 to remove the existing particulate matter.

[0046] After the above process is repeated once or a certain number of times (the number of cycles depends on the metal element content in the initial boron trifluoride gas), boron trifluoride gas with extremely low metal element content can be obtained, and metal elements such as Fe, Ni, Cr, Mn, Co, and Cu in the boron trifluoride gas can be effectively removed. Boron trifluoride gas with a metal element content of less than 10 ppb can be obtained.

[0047] Specifically, the anhydrous hydrogen fluoride liquid storage tank needs to be controlled at 0°C to 5°C.

[0048] The anhydrous hydrogen fluoride storage tank 100 is a steel storage tank with a jacket, and salt water at -10°C to -15°C is passed through the jacket to keep it at a relatively low temperature. The anhydrous hydrogen fluoride liquid storage tank contains a gas-liquid mixer 130 to fully mix the boron trifluoride gas and the anhydrous hydrogen fluoride liquid.

[0049] Boron trifluoride gas enters the anhydrous hydrogen fluoride storage tank 100 in a top-in and top-out manner, wherein the air inlet pipe is connected to the gas-liquid mixer 130 in the storage tank, and the liquid reflux pipe 600 is located at the top of the anhydrous hydrogen fluoride storage tank 100. The liquid reflux pipe 600 is the coolant discharge port of the condenser 200, specifically the cooled hydrogen fluoride liquid.

[0050] The condenser 200 is placed at an angle, the working temperature of the condenser 200 is -8°C to -10°C, the angle of inclination is 3° to 5°, the drainage is gravity drainage, and the temperature of the second outlet 220 of the condenser 200 is controlled at 0°C to 5°C.

[0051] according to Figure 1 As shown, the gas supply uses a steel cylinder of boron trifluoride gas (purity ≥ 99.99 volume %), and the anhydrous hydrogen fluoride storage tank 100 is filled to a liquid level of about 60% (HF purity ≥ 99.99 volume %). The boron trifluoride gas inlet pipeline is equipped with a mass flow meter 140 and a regulating valve 150 to control the gas supply of each gas. The adsorbent storage tank 300 uses a metal fluoride filling part, using a nickel tube with a diameter of 1 inch (25.4 mm) × 200 mm, which is filled with 100-200 grams of adsorbent particles. The adsorbent storage tank 300 is maintained at room temperature, and the operating temperature of the adsorbent storage tank 300 is 5°C to 25°C. The content of the metal component is determined by an inductively coupled plasma mass spectrometer (ICP-MS).

[0052] The processing results are shown in Table 1, Table 2 and Table 3:

[0053] Table 1 Metal ion content of boron trifluoride gas

[0054]

[0055] Among them, the temperature of the second outlet 220 of the condenser 200 is controlled at 2°C, the packing of the adsorbent storage tank 300 is NaF, and the temperature of the adsorbent storage tank 300 is 20°C.

[0056] Table 2 Metal ion content of boron trifluoride gas

[0057]

[0058] Among them, the temperature of the second outlet 220 of the condenser 200 is controlled at 4°C, the packing of the adsorbent storage tank 300 is KF, and the temperature of the adsorbent storage tank 300 is 15°C.

[0059] Table 3 Metal ion content of boron trifluoride gas

[0060]

[0061] Among them, the temperature of the second outlet 220 of the condenser 200 is controlled at 3°C, the packing of the adsorbent storage tank 300 is NaF, and the temperature of the adsorbent storage tank 300 is 12°C.

[0062] It should be noted that the specific parameters or some reagents in the above embodiments are specific embodiments or preferred embodiments under the concept of the present invention, rather than limitations thereof; those skilled in the art can make adaptive adjustments within the concept and protection scope of the present invention.

Claims

1. A purification system for boron trifluoride gas, characterized in that, The purification system for boron trifluoride gas includes: An anhydrous hydrogen fluoride storage tank; the anhydrous hydrogen fluoride storage tank is provided with a first inlet and a first outlet, and a gas-liquid mixer is arranged inside the anhydrous hydrogen fluoride storage tank, and the gas-liquid mixer is connected to the first inlet; A condenser; the anhydrous hydrogen fluoride storage tank is provided with a second inlet and a second outlet, and the second inlet is connected to the first outlet; An adsorbent storage tank; the adsorbent storage tank is provided with a third inlet and a third outlet, and the third inlet is connected to the second outlet; A filter; the filter includes a fourth inlet and a fourth outlet, and the fourth inlet is connected to the third outlet; The adsorbent in the adsorbent storage tank includes metal fluoride.

2. The purification system of boron trifluoride gas according to claim 1, wherein The purification system for boron trifluoride gas further includes a cooling jacket, and the cooling jacket is sleeved outside the anhydrous hydrogen fluoride storage tank.

3. The purification system of boron trifluoride gas according to claim 2, wherein The cooling jacket is provided with a first thermometer.

4. The purification system of boron trifluoride gas according to claim 1, characterized in that, The purification system for boron trifluoride gas further includes a liquid-phase reflux pipeline, and the liquid-phase reflux pipeline connects the condenser and the anhydrous hydrogen fluoride storage tank.

5. The purification system for boron trifluoride gas according to claim 1, characterized in that, The anhydrous hydrogen fluoride storage tank is provided with a liquid level gauge.

6. The purification system for boron trifluoride gas according to claim 1, characterized in that, The second outlet is provided with a second thermometer.

7. The purification system for boron trifluoride gas according to claim 1, wherein The third inlet is provided with a first pressure transmitter, and the fourth inlet is provided with a second pressure transmitter.

8. The purification system of boron trifluoride gas according to claim 1, wherein The adsorbent storage tank is provided with a temperature transmitter.

9. The purification system of boron trifluoride gas according to claim 1, characterized in that, The fourth inlet is provided with a third pressure transmitter, and the fourth outlet is provided with a fourth pressure transmitter.

10. The purification system of boron trifluoride gas according to claim 1, characterized in that, The filter is a high-precision filter.

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