System and method for continuous reaction and raw material recycling of electronic-grade diborane

Abstract

The invention aims to provide a continuous reaction and raw material recycling system for electronic-grade diborane. The system comprises a solid-liquid mixer, a liquid filter, a gas filter, a pipeline mixer, a U-shaped tubular reactor and a gas-liquid separator, segmented control is achieved through the U-shaped tubular reactors connected in series, fluid turbulence is enhanced, backmixing is reduced, and the contact efficiency of reactants is improved. Meanwhile, efficient separation and collection are realized based on the boiling point difference of the materials, a closed-loop recovery system is constructed, and the cyclic utilization rate of the raw materials is increased, so that a high-yield and high-quality diborane product is obtained.

Description

Technical Field

[0001] This invention relates to a continuous reaction and raw material recycling system for electronic-grade diborane, belonging to the field of electronic-grade specialty gas synthesis. Background Technology

[0002] Diborane (B₂H₆) is a boron-hydrogen compound with a boiling point of -92.5℃. It is a highly reactive inorganic compound, extremely toxic, and a colorless gas at room temperature. It spontaneously combusts and explodes in air and decomposes upon contact with water. Electronic-grade diborane plays an irreplaceable role in high-tech fields. In the electronics industry, it is used as a gaseous impurity source, a dopant for ion implantation and boron doping oxidation diffusion, primarily as a dopant in the production of P-type semiconductor chips. Diborane pretreatment has become a standard step in DRAM and 3D NAND processes below 28nm. As a core material in the semiconductor, photovoltaic, and optoelectronic industries, the depth and breadth of diborane's applications continue to expand with technological advancements. In the future, accelerated domestic substitution, growing demand in emerging fields, and breakthroughs in environmental protection technologies will be key directions for the industry's development.

[0003] Currently, common industrial methods for producing diborane include sodium borohydride reduction and electrolysis. The tetraaluminum hydride reduction method, which involves the reduction of boron trifluoride (BF3) by lithium aluminum hydride to produce diborane (B2H6), offers relatively mild reaction conditions, typically carried out in ether solvents (such as diethyl ether). It does not require extreme high temperatures and pressures, produces fewer byproducts, and has a stable source of raw materials, making it suitable for large-scale production of high-purity diborane. Therefore, developing a method for producing diborane that is applicable to large-scale industrial production, with high yield, high purity, safety, and low cost is of great significance. A process utilizing a series of continuous reactions and a gas-liquid separation recycling system to produce electronic-grade diborane is safe and stable, effectively achieving efficient resource recycling, and is both economical and environmentally friendly. Summary of the Invention

[0004] The purpose of this invention is to provide a continuous reaction and raw material recycling system for electronic-grade borane, which is safe and stable and can effectively achieve low-cost and high-efficiency production of high-quality borane.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A continuous reaction and gas-liquid separation circulation system for electronic-grade diborane is provided, including a solid-liquid mixer, a gas filter, a pipeline mixer, a U-shaped tubular reactor, a gas-liquid separator, a liquid filter, etc., and its production steps are as follows: Solid-liquid mixer: used to dissolve and mix lithium aluminum hydride (solid white crystals) and solvent (the solvent includes tetrahydrofuran) to form a mixed solution. The lower end of the solid-liquid mixer is connected to the upper end of the U-shaped tubular reactor through a pipe, and the mixed solution is transported to the U-shaped tubular reactor by a solution circulation pump.

[0006] Gas filter: The gas filter is connected to the Y-cylinder of boron trifluoride and a sintered filter element with a precision of 1 micrometer or less is used to fully filter the gas to remove moisture and particulate matter from the boron trifluoride gas, so as to maintain the purity of the raw material gas.

[0007] The sintered filter element is a stainless steel sintered filter element, mainly used to control moisture content to <100ppb and total metal ion content to <10ppm.

[0008] Pipeline mixer: By controlling the mixed feed of inert gas and boron trifluoride gas, the inert gas and boron trifluoride gas are mixed to form a mixed gas.

[0009] In some embodiments, the inert gas includes one or more combinations of argon, helium, and nitrogen.

[0010] U-shaped tubular reactor: The upper section of the U-shaped tubular reactor is connected in series by pipes, and the bottom of the U-shaped tubular reactor is provided with independent raw material gas inlets, which are used to allow the mixed gas from the pipe mixer to enter the U-shaped tubular reactor and react with the mixed solution from the solid-liquid mixer.

[0011] It can be understood that at least three independent U-shaped tubular reactors are connected in series to form a U-shaped tubular reactor unit group, collectively referred to as a U-shaped tubular reactor.

[0012] In some embodiments, two U-shaped tubular reactor units are formed, with one operating and the other on standby during operation to ensure reaction stability.

[0013] Tetrahydrofuran gas-liquid separator: The upper end of the tetrahydrofuran gas-liquid separator is connected to the upper end of the U-shaped tubular reactor through a pipe, and the tetrahydrofuran and other substances from the U-shaped tubular reactor are separated into gas and liquid components. Liquid filter: The liquid filter is connected to the bottom of the tetrahydrofuran gas-liquid separator and combined with a stainless steel filter element (5 microns and below) for filtration to remove particulate matter from the tetrahydrofuran solution.

[0014] The tetrahydrofuran solution filtered by the liquid filter is transported from the pipeline to the solid-liquid mixer by a solution transport pump for recycling, and fresh solution is added as needed based on operating conditions.

[0015] Diborane gas-liquid separator: The upper end of the diborane gas-liquid separator is connected to the upper end of the tetrahydrofuran gas-liquid separator through a pipeline, and diborane from the tetrahydrofuran gas-liquid separator and other substances are separated into gas and liquid components.

[0016] The lower end of the borane gas-liquid separator is also provided with a solution outlet, from which borane liquid product with a purity >99.9% is collected from the bottom of the borane gas-liquid separator and transported through pipeline to an intermediate buffer tank or to the next stage for purification.

[0017] Boron trifluoride gas-liquid separator: The upper end of the boron trifluoride gas-liquid separator is connected to the upper end of the diborane gas-liquid separator through a pipeline, and the boron trifluoride and inert gas from the diborane gas-liquid separator are separated into gas and liquid components.

[0018] The upper end of the boron trifluoride gas-liquid separator is provided with a gas outlet to discharge inert gas, and the lower end of the boron trifluoride gas-liquid separator is also provided with a solution outlet. The boron trifluoride can be transported to the front end of the gas filter by a pump to realize the recycling of resources.

[0019] Furthermore, the solid-liquid mixing tank is equipped with a feeding port for lithium aluminum hydride solid.

[0020] Furthermore, an electric heating tape is installed on the gas transport pipeline at the rear end of the gas filter.

[0021] It is understandable that pumps and / or on / off valves are installed on the pipeline according to the needs of the equipment operation.

[0022] This invention provides a method for synthesizing diborane using this reaction system, as follows: Prepare and mix the raw materials according to the formula. Add solid lithium aluminum hydride with a mass purity >99% into the solid-liquid mixer through the solid feed port above the solid-liquid mixer. After the lithium aluminum hydride is fed into the solid-liquid mixer, add solvent. Mix the solid lithium aluminum hydride and tetrahydrofuran solvent evenly to form a reaction solution.

[0023] The mixed solution is transported through a pipeline by the solution circulation pump to the upper inlet of the U-shaped tubular reactor and fed into the U-shaped tubular reactor; at the same time, the mixed gas from the pipeline mixer is transported through a pipeline to the bottom air inlet of the U-shaped tubular reactor.

[0024] The material discharged from the top of the U-shaped tubular reactor includes diborane, inert gas, solution material, and trace amounts of unreacted boron trifluoride. This material is then transported sequentially through pipelines to the tetrahydrofuran gas-liquid separator, the diborane gas-liquid separator, and the boron trifluoride gas-liquid separator. The tetrahydrofuran flows out from the bottom outlet of the tetrahydrofuran gas-liquid separator and proceeds to the solid-liquid mixer. The inert gas exits from the top outlet of the boron trifluoride gas-liquid separator. After cooling, the diborane liquefies and flows out from the bottom of the diborane gas-liquid separator, entering an intermediate buffer tank or a subsequent purification unit to prepare 5N-grade diborane.

[0025] The solvent includes tetrahydrofuran; the concentration of the lithium aluminum hydride mixed solution is 0.05-0.5 g / ml. In some preferred embodiments, the concentration of the lithium aluminum hydride mixed solution is 0.1-0.3 g / ml. The lithium aluminum hydride mixed solution and the boron trifluoride mixed gas are introduced into the U-shaped tube reactor at rates of 0.5-3 kg / h, preferably 1.2-1.5 kg / h.

[0026] In order to ensure uniform mixing of raw materials, the solid-liquid mixer is equipped with a container heating layer at the outer end of the equipment, and the heating temperature is controlled at 25-35℃.

[0027] Furthermore, the inert gas includes one or more combinations of high-purity helium, high-purity argon, and high-purity nitrogen, and the mass purity of the inert gas is >99.99%.

[0028] The mass mixing ratio of boron trifluoride and inert gas in the mixed gas is 2-10:1, preferably 3:1, and the mass purity of the boron trifluoride gas is >99.99%.

[0029] Furthermore, the U-shaped tubular reactors are connected in series, with the temperature controlled at 20~30℃. Each reactor has an inlet for mixed gas from bottom to top, and the gas inlet velocity of each inlet is 1.0-5 kg / h, preferably 1.5-2.0 kg / h. The mixed gas is fed in excess. In order to ensure experimental safety and precise control of reaction conditions, each U-shaped tubular reactor is equipped with a pressure gauge.

[0030] The temperature of the tetrahydrofuran gas-liquid separator is controlled at 0~10℃, the temperature of the diborane gas-liquid separator is controlled at -90~-100℃, and the temperature of the boron trifluoride gas-liquid separator is controlled at -100~-110℃. In addition, pressure gauges are installed on each gas-liquid separator.

[0031] Furthermore, the bottom end of the tetrahydrofuran gas-liquid separator is equipped with an electric heating belt; the bottom end of the boron trifluoride gas-liquid separator is equipped with a heat insulation layer.

[0032] The synthesis reaction of diborane is carried out using the reaction system of the present invention. In the U-shaped tubular reactor, lithium aluminum hydride and boron trifluoride in the reaction solvent react to generate a small amount of gaseous byproducts and solid impurities. The gaseous byproducts include carbon dioxide, methane, ethane, etc. Because the reaction solvent is in a flowing state in the U-shaped tubular reactor (equipment model of U-shaped tubular reactor: Guizhou Microchemical Technology, LT microchannel reactor), when gas is introduced into the liquid, a dynamic interface is formed at the gas-liquid interface. Due to the density difference between the gas and liquid (gas density is much smaller than liquid), bubbles rise under buoyancy. During the ascent, the bubble volume expands due to pressure changes, and simultaneously drives the liquid flow through shearing action, forming a circulating flow state. Furthermore, the continuous addition of mixed gas ensures thorough mixing of the reactants. The reaction process occurs according to the following reaction formula: LiAlH4+ BF3→ B2H6+ AlF3+ LiF.

[0033] The U-shaped tubular reactor group formed in series adopts a one-on-one standby state to ensure the normal operation of the entire reaction system when cleaning solid impurities at the bottom of the reactor.

[0034] The filtration equipment (such as liquid filters and gas filters) is configured with one in operation and one on standby to ensure that the filter components can alternately perform filtration and cleaning, thereby ensuring that the overall reaction system can always operate normally.

[0035] This invention provides a continuous reaction and raw material recycling system for the efficient synthesis of diborane. Compared with existing equipment, this invention optimizes equipment and processes. Compared with traditional batch reactors, the series U-tube reactor can achieve segmented control, enhance fluid turbulence, reduce backmixing, and improve reactant contact efficiency. At the same time, it achieves efficient separation and collection based on the difference in boiling points of materials, constructs a closed-loop recovery system, improves the recycling rate of raw materials, and obtains high-yield, high-quality diborane products. Attached Figure Description

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0037] Figure 1 Here is a process flow diagram of the present invention: 1-Boron trifluoride Y-type bottle, 2-Liquid filter, 3-Gas filter, 4-Solid-liquid mixer, 5-Pipeline mixer, 6-U-shaped tubular reactor, 7-Tetrahydrofuran gas-liquid separator, 8-Diborane gas-liquid separator, 9-Boron trifluoride gas-liquid separator, 10-Heating pipeline. Detailed Implementation

[0038] Boron trifluoride Y-bottle: Seronte Y-bottle.

[0039] Liquid filter: Hangzhou Dali XHF high-flow pleated filter cartridge.

[0040] Gas filter: Hangzhou Dali Has-cleen integrated electronic-grade stainless steel gas filter element.

[0041] Solid-liquid mixer: SJBF-1.1 from Seher Intelligent Equipment (Shanghai) Co., Ltd.

[0042] Pipeline mixer: The mixing ratio of two gases (helium and boron trifluoride) is precisely controlled by a mass flow controller.

[0043] U-shaped tubular reactor: Guizhou Microchemical Technology LT microchannel reactor.

[0044] Tetrahydrofuran gas-liquid separator: Stainless steel pressurized distillation unit from Aishengke (Jiangsu) Chemical Technology Co., Ltd.

[0045] Borane gas-liquid separator: Stainless steel pressurized distillation unit from Aishengke (Jiangsu) Chemical Technology Co., Ltd.

[0046] Boron trifluoride gas-liquid separator: Stainless steel pressurized distillation unit from Aishengke (Jiangsu) Chemical Technology Co., Ltd.

[0047] Example 1 A system for synthesizing diborane, comprising the following structure: Solid-liquid mixer 4 is used to mix lithium aluminum hydride and solvent to form a lithium aluminum hydride mixed solution; Pipeline mixer 5 is used to mix boron trifluoride and inert gas to form a boron trifluoride mixed gas; The U-shaped tubular reactor 6 has its top inlet connected to the bottom outlet of the solid-liquid mixer 4, and its bottom inlet connected to the outlet of the pipe mixer 5, which is used to provide a reaction site for the lithium aluminum hydride mixed solution and the boron trifluoride mixed gas. The gas-liquid separator has its top inlet connected to the top outlet of the U-shaped tubular reactor 6 to achieve gas-liquid separation and obtain liquid diborane.

[0048] The solvent is equipped with a liquid filter 2, which contains a stainless steel filter element with a 5-micron pore size to remove particulate matter from the solvent. The liquid filter 2 is provided in two sets, one in operation and one on standby. Figure 1 (The remaining text is not shown, but will be understood by those skilled in the art). The boron trifluoride is equipped with a gas filter 3, which contains a sintered filter element with a pore size of 1 micrometer to remove moisture and particulate matter from the boron trifluoride gas. The gas filter 3 is provided in two sets, one on and one on standby. Figure 1 (The remaining text is not shown, but will be understood by those skilled in the art). The gas filter 3 is connected to a heat tracing pipe 10 at its front end for adding boron trifluoride raw material.

[0049] The U-shaped tubular reactor 6 consists of three sets of U-shaped tubular reactors connected in series to form a U-shaped tubular reactor group; If two sets of U-shaped tubular reactors are formed, then one will be in operation and the other will be on standby. Figure 1 (The details are not shown in the image, but will be understood by those skilled in the art).

[0050] The gas-liquid separator includes a tetrahydrofuran gas-liquid separator 7, a diborane gas-liquid separator 8, and a boron trifluoride gas-liquid separator 9. The upper inlet of the tetrahydrofuran gas-liquid separator 7 is connected to the upper outlet of the U-shaped tubular reactor to separate tetrahydrofuran and other substances from the U-shaped tubular reactor into gas and liquid components. The lower end of the tetrahydrofuran gas-liquid separator 7 is also provided with a solution outlet, which is circulated back to the solid-liquid mixer; The upper inlet of the borane gas-liquid separator 8 is connected to the upper outlet of the tetrahydrofuran gas-liquid separator 7 via a pipeline, which separates borane from other substances in gas and liquid form. The lower end of the borane gas-liquid separator is also provided with a solution outlet, which can transport borane to an intermediate buffer tank or the next stage. The upper inlet of the boron trifluoride gas-liquid separator 9 is connected to the upper outlet of the diborane gas-liquid separator 8 via a pipeline, thereby separating boron trifluoride and inert gas from the diborane gas-liquid separator. The lower end of the boron trifluoride gas-liquid separator is also provided with a solution outlet, which transports boron trifluoride to the front end of the gas filter to realize the recycling of resources.

[0051] Example 2 The method for synthesizing diborane using the system of Example 1 includes the following steps: Prepare and mix the raw materials according to the formula. Add solid lithium aluminum hydride with a mass purity >99% into the solid-liquid mixer through the solid feed port above the solid-liquid mixer. After the electronic scale shows that 390g of lithium aluminum hydride has been fed into the solid-liquid mixer, add 3000g of tetrahydrofuran solvent. Mix the solid lithium aluminum hydride and tetrahydrofuran solvent evenly according to the formula to form a reaction solution. The diborane U-tube reactor is a continuous reactor with a height of 1.2 meters, an inner cylinder diameter of 0.4 meters, and an outer cylinder diameter of 0.6 meters. First, inert gas is used to thoroughly replace and purify the pipelines related to material feeding in the diborane U-tube reactor, repeating this process 20 times. Then, a lithium aluminum hydride mixed solution is injected into the diborane U-tube reactor through the flanged feed port of the diborane synthesizer, after which the flanged feed port is closed. 99.99% electronic-grade boron trifluoride is fed from the bottom of the U-tube reactor. The mixed solution is transported to the upper inlet of the U-shaped tubular reactor via a solution circulation pump and a pipeline, and fed into the U-shaped tubular reactor at a rate of 1.2 kg / h. Simultaneously, a mixed gas from the pipeline mixer (the mass ratio of boron trifluoride to inert gas in the mixed gas is 3:1, and the gas inlet velocity at each inlet is 1.5 kg / h) is transported to the bottom inlet of the U-shaped tubular reactor via a pipeline to allow it to react fully, as follows: LiAlH4 + BF3 → B2H6 + AlF3 + LiF. The material discharged from the top of the U-shaped tubular reactor includes diborane, inert gas, solution material, and trace amounts of unreacted boron trifluoride. This material is then sequentially transported through pipelines to the tetrahydrofuran gas-liquid separator, the diborane gas-liquid separator, and the boron trifluoride gas-liquid separator. The temperature of the tetrahydrofuran gas-liquid separator is controlled at 0~10℃, the temperature of the diborane gas-liquid separator is controlled at -90~-100℃, and the temperature of the boron trifluoride gas-liquid separator is controlled at -100~-110℃. Each gas-liquid separator is equipped with a pressure gauge (maintaining a slightly positive pressure of 0.1-0.2 MPa), and is protected with an inert gas (such as helium) to prevent oxygen from causing combustion, explosion, or chemical reactions. Tetrahydrofuran flows out from the bottom outlet of the tetrahydrofuran gas-liquid separator and goes to the solid-liquid mixer. Inert gas is discharged from the top outlet of the boron trifluoride gas-liquid separator. After being cooled, borane is liquefied and flows out from the bottom of the borane gas-liquid separator. The purity of tetrahydrofuran is 97%, and the purity of boron trifluoride after passing through the gas filter is 99.99%. The bottom of the borane gas-liquid separator collects borane liquid product with a purity >98%, which is transported through pipeline to an intermediate buffer tank or to the next stage for purification treatment, with a yield of 72%.

[0052] Example 3 The specific embodiments of the synthesis method of high-purity electronic-grade diborane and the separation method of high-purity diborane from raw materials of the present invention are as follows: Prepare and mix the raw materials according to the formula. Add solid lithium aluminum hydride with a mass purity >99% into the solid-liquid mixer through the solid feed port above the solid-liquid mixer. After the electronic scale shows that 400g of lithium aluminum hydride has been fed into the solid-liquid mixer, add 4400g of tetrahydrofuran solvent. Mix the solid lithium aluminum hydride and tetrahydrofuran solvent evenly according to the formula to form a reaction solution. The diborane U-tube reactor is a continuous reactor with a height of 1.2 meters, an inner cylinder diameter of 0.4 meters, and an outer cylinder diameter of 0.6 meters. First, inert gas is used to thoroughly replace and purify the pipelines related to material feeding in the diborane U-tube reactor, repeating this process 20 times. Then, a lithium aluminum hydride mixed solution is injected into the diborane U-tube reactor through the flanged feed port of the diborane synthesizer, after which the flanged feed port is closed. 99.99% electronic-grade boron trifluoride is fed from the bottom of the U-tube reactor. The mixed solution is transported to the upper inlet of the U-shaped tubular reactor via a solution circulation pump and pipeline at a rate of 1.2 kg / h. Simultaneously, a mixed gas from the pipeline mixer (with a mass ratio of boron trifluoride to inert gas of 3:1 and an inlet velocity of 1.5 kg / h at each inlet) is transported to the bottom inlet of the U-shaped tubular reactor via pipeline to allow for a complete reaction, as follows: LiAlH4 + BF3 → B2H6 + AlF3 + LiF. The material discharged from the top of the U-shaped tubular reactor includes diborane, inert gas, solution material, and trace amounts of unreacted boron trifluoride. This material is then sequentially transported through pipelines to the tetrahydrofuran gas-liquid separator, the diborane gas-liquid separator, and the boron trifluoride gas-liquid separator. The temperature of the tetrahydrofuran gas-liquid separator is controlled at 5~15℃, the temperature of the diborane gas-liquid separator is controlled at -70~-85℃, and the temperature of the boron trifluoride gas-liquid separator is controlled at -85~-100℃. Each gas-liquid separator is equipped with a pressure gauge (maintained under pressure, 0.25-0.35 MPa), and inert gas is used for protection to prevent oxygen from causing combustion, explosion, or chemical reactions. Tetrahydrofuran flows out from the bottom outlet of the tetrahydrofuran gas-liquid separator and goes to the solid-liquid mixer. Inert gas is discharged from the top outlet of the boron trifluoride gas-liquid separator. After being cooled, borane is liquefied and flows out from the bottom of the borane gas-liquid separator. The purity of tetrahydrofuran is 99%, the purity of boron trifluoride is 99.99%, the purity of borane is 99%, and the yield is 78%.

[0053] Comparative Example 1 This application provides an apparatus and method for producing electronic-grade phosphorus trifluoride and co-producing high-purity hydrogen chloride. Similar to Example 1, the reactor and related pipelines for material feeding are thoroughly replaced and purified 20 times. The only difference from Example 1 is the use of a stirred tank reactor, where solid-liquid mixing and raw material reaction are completed within the reactor. The liquid feed rate is 1.2 kg / h, and the gas feed rate is 1.5 kg / h (the mass ratio of boron trifluoride to inert gas in the mixed gas is 3:1). Insufficient agitation of the solid and liquid within the reactor leads to uneven mixing of reactants, resulting in a slow and incomplete reaction. The final product obtained is electronic-grade diborane with a yield of 54% and a purity molar fraction of 95%. However, a significant amount of unreacted solid residue remains, causing blockages in some pipelines and posing a certain safety risk.

Claims

1. A continuous reaction and raw material recycling system for electronic-grade diborane, characterized in that, A solid-liquid mixer is used to mix lithium aluminum hydride and a solvent to form a lithium aluminum hydride mixed solution; Pipeline mixer, used to mix boron trifluoride and inert gas to form boron trifluoride mixed gas; The U-shaped tubular reactor has its top inlet connected to the bottom outlet of the solid-liquid mixer and its bottom inlet connected to the outlet of the pipe mixer. It is used to provide a reaction site for the lithium aluminum hydride mixed solution and the boron trifluoride mixed gas. The gas-liquid separator has its top inlet connected to the top outlet of the U-shaped tubular reactor to achieve gas-liquid separation and obtain liquid diborane.

2. The continuous reaction and raw material recycling system for electronic-grade diborane according to claim 1, characterized in that, The solvent is equipped with a liquid filter, which contains a stainless steel filter element with a pore size of 5 micrometers or less to remove particulate matter from the solvent. The liquid filter is provided in at least two sets, with one set in operation and one set in standby. The boron trifluoride is equipped with a gas filter, which contains a sintered filter element with a pore size of 1 micrometer or less, used to remove moisture and particulate matter from the boron trifluoride gas. At least two sets of gas filters are provided, with one set in operation and one set on standby. The gas filter is connected to a heat tracing pipe at its front end for adding boron trifluoride raw material.

3. The continuous reaction and raw material recycling system for electronic-grade diborane according to claim 1, characterized in that, The U-shaped tubular reactor is formed by connecting at least three U-shaped tubular reactors in series to form a U-shaped tubular reactor group; If two sets of U-shaped tubular reactors are formed, then one will be in operation and the other will be on standby.

4. The continuous reaction and raw material recycling system for electronic-grade diborane according to claim 1, characterized in that, The gas-liquid separators include tetrahydrofuran gas-liquid separators, diborane gas-liquid separators, and boron trifluoride gas-liquid separators. The upper inlet of the tetrahydrofuran gas-liquid separator is connected to the upper outlet of the U-shaped tubular reactor to separate tetrahydrofuran and other substances from the U-shaped tubular reactor into gas and liquid components. The lower end of the tetrahydrofuran gas-liquid separator is also provided with a solution outlet, which is circulated back to the solid-liquid mixer. The upper inlet of the borane gas-liquid separator is connected to the upper outlet of the tetrahydrofuran gas-liquid separator through a pipeline, which separates borane from other substances in the tetrahydrofuran gas-liquid separator. The lower end of the borane gas-liquid separator is also provided with a solution outlet, which can transport borane to an intermediate buffer tank or the next process stage. The upper inlet of the boron trifluoride gas-liquid separator is connected to the upper outlet of the diborane gas-liquid separator via a pipeline, thereby separating the boron trifluoride and inert gas from the diborane gas-liquid separator. The lower end of the boron trifluoride gas-liquid separator is also provided with a solution outlet, which transports the boron trifluoride to the front end of the gas filter to realize the recycling of resources.

5. A method for continuous reaction and raw material recycling of electronic-grade diborane, characterized in that, Includes the following steps: (1) Lithium aluminum hydride and solvent are mixed to form a lithium aluminum hydride mixed solution; (2) Boron trifluoride and an inert gas are mixed to form a boron trifluoride mixed gas; (3) The lithium aluminum hydride mixed solution and the boron trifluoride mixed gas are fed from the top and bottom of the U-shaped tube reactor, respectively, so that the reaction takes place in the U-shaped tube reactor. The product after the reaction is separated into gas and liquid to obtain diborane liquid.

6. The method for continuous reaction and raw material recycling of electronic-grade diborane according to claim 5, characterized in that, The solvent mentioned in step (1) includes tetrahydrofuran; the concentration of the lithium aluminum hydride mixed solution is 0.05-0.5 g / ml.

7. The method for continuous reaction and raw material recycling of electronic-grade diborane according to claim 5, characterized in that, In step (2), the mass mixing ratio of boron trifluoride and inert gas is 2-10:

1.

8. The method for continuous reaction and raw material recycling of electronic-grade diborane according to claim 5, characterized in that, In step (3), the rates at which the lithium aluminum hydride mixed solution and the boron trifluoride mixed gas enter the U-shaped tube reactor are 0.5-3 kg / h and 1.0-5 kg / h, respectively.

9. The method for continuous reaction and raw material recycling of electronic-grade diborane according to claim 5, characterized in that, Are there any reaction conditions in step (3) with a pressure of 0.1-0.2 MPa and a reaction temperature of -45℃ to -35℃? 10. The method for continuous reaction and raw material recycling of electronic-grade diborane according to claim 5, characterized in that, The gas-liquid separation in step (3) includes tetrahydrofuran gas-liquid separation, diborane gas-liquid separation, and boron trifluoride gas-liquid separation; wherein, The separation temperature during the gas-liquid separation process of tetrahydrofuran is 0~10℃; The separation temperature during the gas-liquid separation process of diborane is -90~-100℃; The separation temperature during the boron trifluoride gas-liquid separation process is -100~-110℃.

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