Device and method for continuously synthesizing disilane through discharge reaction

Abstract

The invention discloses a device and method for continuously synthesizing disilane through a discharge reaction, the device comprises a plasma reactor, an adsorption tower and two rectifying towers, an annular electrode anode and an annular electrode cathode are arranged in the plasma reactor, and the electrode anode and the electrode cathode are coaxially arranged. The synthesis method comprises the following steps: evacuating a device for continuously synthesizing disilane through discharge reaction until the absolute pressure is 5-10 Pa; preheating the plasma reactor to 60-100 DEG C; monosilane and hydrogen enter a first buffer tank through a flow meter to be mixed; introducing the mixed gas into a plasma reactor for reaction, wherein the reaction temperature is 60-100 DEG C; a product obtained after reaction enters a cold trap, and part of high-order silane is removed; pumping the crude disilane gas subjected to cold trap into an adsorption tower through a compressor for adsorption, and removing moisture and part of carbon dioxide; and feeding the adsorbed gas into a rectifying tower for rectifying to obtain the electronic-grade disilane with the purity of 5N and above. The device and the method are safe, high in disilane selectivity, low in energy consumption and good in product quality.

Description

Technical Field

[0001] This invention relates to an electrochemical synthesis technology, specifically to a method and apparatus for the continuous synthesis of silane (Si2H6) using DC discharge plasma technology, applicable to the fields of semiconductor materials, photovoltaic materials, and specialty chemicals preparation. Background Technology

[0002] Silane is a key raw material in the manufacture of semiconductor and photovoltaic materials. In the fabrication of semiconductor devices, silane can be used in chemical vapor deposition (CVD) processes to prepare high-quality monocrystalline and polycrystalline silicon thin films. In the photovoltaic industry, it can be used to prepare silicon thin films, improving the conversion efficiency of solar cells. Furthermore, as an important raw material for the synthesis of organosilicon, silane can also be used to prepare materials such as silicone oil, silicone resin, and silicone rubber, showing broad application prospects.

[0003] Currently, the main methods for synthesizing silane include the reaction of silane with chlorine, direct synthesis of silane, catalytic conversion of silane and hydrogen, and reaction of magnesium silicide with ammonium chloride. Patent document CN 118929667 A discloses a method for preparing silane by catalytic reaction of silane and chlorine. This method involves mixing silane and chlorine gas and then introducing the mixture into a fixed-bed reactor for catalytic reaction within a temperature range of 0-10°C, yielding a mixture of silane, chlorosilane, and hydrogen chloride. However, due to the large number of byproducts, multiple cyclic reactions are required to improve the utilization rate of these byproducts. Patent document CN 115477305 A discloses a method for directly synthesizing silane from silane. This method uses silane as a raw material and, under reaction conditions of 120°C to 380°C and reaction pressure of 1.2-3.0 MPa, obtains a reaction product containing silane, silane, propane, and hydrogen through a catalytic reaction in a fixed-bed reactor, achieving a single-pass yield of up to 20%. After filtering, cooling, separating, and purifying the reaction product, 6N silane was obtained. This method has a high yield, but its synthesis requires high-temperature and high-pressure conditions, placing high demands on personnel operation and reaction equipment. It also faces the problem of catalyst deactivation.

[0004] The current mainstream synthesis method utilizes magnesium silicide and ammonium chloride to synthesize disilane, a reaction carried out in a liquid ammonia medium. This involves mixing magnesium silicide and ammonium chloride in a specific ratio to produce disilane, magnesium chloride, and higher-order silanes. Patent document CN 114715900 A discloses a method for the continuous synthesis of disilane using magnesium silicide and ammonium chloride. Magnesium powder and silicon powder are added to a mixer in a specific ratio and mixed evenly. The mixture is then added to a vacuum reactor at a temperature of 400–600℃ and a pressure of -0.075–0.12 MPa. After heating and holding at this temperature, a magnesium-silicon alloy (magnesium silicide) is obtained. This magnesium-silicon alloy is then added to a reactor at a reaction temperature of -5–50℃ and a pressure of 0.01–0.03 MPa. Dry ammonium chloride is introduced, and the reaction proceeds for 3–10 hours to obtain crude disilane. Electronic-grade disilane is then obtained after purification using a multi-stage distillation unit. However, when magnesium powder and silicon powder are mixed to prepare alloyed magnesium silicide, the alloying degree of magnesium silicide is low, resulting in significant material waste. Furthermore, this method also currently faces problems with low selectivity and yield of silane.

[0005] Therefore, providing an efficient method for the synthesis of silanes is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] To address the shortcomings of existing preparation technologies, the first objective of this invention is to provide an apparatus for the continuous synthesis of silane via a discharge reaction.

[0007] A second objective of this invention is to provide a method for the continuous synthesis of silane via a discharge reaction.

[0008] To achieve the first objective mentioned above, the present invention provides an apparatus for the continuous synthesis of silane via discharge reaction, comprising a plasma reactor 6, an adsorption tower 11, and two distillation towers. The plasma reactor 6 is internally equipped with an annular electrode anode 6-2 and an annular electrode cathode 6-3, which are coaxially arranged. A heat exchange jacket 6-1 is externally installed on the plasma reactor 6. The upper part of the plasma reactor 6 is connected to a first buffer tank 5, followed by connections to a silane cylinder 1 and a hydrogen cylinder 2. A silane flow meter 4 is installed between the first buffer tank 5 and the silane cylinder 1, and a hydrogen flow meter 3 is installed between the first buffer tank 5 and the hydrogen cylinder 2. One branch of the bottom of the plasma reactor 6 connects to a second buffer tank 7 and a vacuum pump 8, while another branch connects to the top of the adsorption tower 11 via a cold trap 9 and a compressor 10. The bottom of the adsorption tower 11 is connected to the middle of the first distillation tower 13 via a filter tank 12. The top of the first distillation tower 13 is connected to a vent pipe, and its bottom is connected to the middle of the second distillation tower 14. All components are connected via pipes and valves.

[0009] Furthermore, the flow rates of the hydrogen flow meter 3 and the silane flow meter 4 are preferably 0~500 mL / min.

[0010] Furthermore, the first buffer tank 5 and the second buffer tank 7 are equipped with pressure sensors, preferably with a range of 0~0.3 MPa.

[0011] Furthermore, the anode material is preferably a molybdenum-doped graphene-silicon carbide hollow electrode with a wall thickness of 5 mm and an outer diameter of 30-50 mm; the cathode material is preferably a Hastelloy C-276 hollow electrode with a wall thickness of 5 mm and an outer diameter of 10-20 mm.

[0012] Furthermore, the inner wall of the plasma reactor 6 is equipped with a temperature sensor and a pressure sensor. The temperature sensor is preferably measured in the range of 0~200 ℃, and the pressure sensor is preferably measured in the range of 0~0.30 MPa.

[0013] Furthermore, the preferred pumping speed of the vacuum pump is 3~5 m / s. 3 / h, the ultimate vacuum can reach 5 Pa under absolute pressure.

[0014] Furthermore, a temperature sensor and a cooling coil are installed inside the cold trap 9. The lower end of the coil is the cooling liquid inlet, and the upper end is the cooling liquid outlet. The temperature sensor's range is preferably -50~100 ℃.

[0015] Furthermore, the compressor 10 has an adjustable boost pressure range of 0~1 MPa.

[0016] Furthermore, the adsorption tower 11 is preferably made of 316L stainless steel, and its inner diameter is preferably 30~50 mm. The top of the adsorption tower 11 is equipped with an openable and closable cover for filling with adsorbent, which is preferably 5A molecular sieve, activated alumina, or color-changing silica gel.

[0017] Furthermore, the filter element pore size in the filter tank 12 is preferably 0.1 μm; Furthermore, the two distillation columns are preferably made of 316L stainless steel, with an inner diameter of 10-15 mm and a height of 1-3 m. The first distillation column 13 and the second distillation column 14 are made of Sulzer CY700 stainless steel structured packing with a specific surface area ≥700 m² / m³ and a theoretical plate number ≥20 plates / m.

[0018] To achieve the second objective, this invention provides a method for the continuous synthesis of silane via discharge reaction. Using silane as a raw material and H2 as a carrier gas, silane is synthesized via discharge at atmospheric pressure. After passing through a cold trap, adsorption tower, and distillation tower, 5N electronic-grade silane is obtained. The method includes the following steps: Step 1: Evacuate the apparatus for the continuous synthesis of silane via discharge reaction to an absolute pressure of 5-10 Pa; Step 2: Preheat the plasma reactor to 60~100 ℃; Step 3: Mix silane and hydrogen by introducing them into the first buffer tank through a flow meter; Step 4: The mixed gas is introduced into the plasma reactor for reaction at a temperature of 60~100℃; Step 5: The reaction product enters a cold trap to remove some of the higher-order silanes; the higher-order silanes refer to Si... n H 2n+2 n≥3; Step 6: The crude silane gas after the cold trap is drawn to the adsorption tower by the compressor for adsorption, removing moisture and some carbon dioxide; Step 7: The adsorbed gas enters a distillation column for distillation to obtain electronic-grade silane with a purity of 5N or higher.

[0019] Furthermore, the flow rate ratio of silane to hydrogen is 1:(1~5), and the total gas flow rate is preferably 50~200 mL / min.

[0020] Furthermore, the reactor temperature is controlled at a certain temperature point between 60 and 100°C by using a heat exchange jacket.

[0021] Furthermore, the plasma reactor is equipped with a high-frequency pulsed DC power supply with a frequency of 1~10 kHz and a voltage of 5~20 kV. The preferred reaction pressure range inside the reactor is 0.001~0.10 MPa. Furthermore, the temperature of the cold trap is 0 °C, and higher-order silanes with silicon atomic lengths greater than 3 are removed; Furthermore, the distillation columns employ continuous distillation, with an operating pressure preferably between 0.1 and 0.3 MPa. The preferred temperatures for the top of the first distillation column 13 are -40 to -20°C, the preferred temperatures for the bottom are 40 to 60°C, and the preferred temperatures for the condenser are -40 to -20°C. Similarly, the preferred temperatures for the top of the second distillation column 14 are -10 to 10°C, the preferred temperatures for the bottom are 10 to 30°C, and the preferred temperatures for the condenser are -20 to 0°C.

[0022] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention utilizes hydrogen as both a carrier gas and a reactant gas. During discharge, hydrogen promotes the breaking of Si-H bonds in silane, generating highly reactive SiH3· radicals. These radicals are key intermediates in the synthesis of disilane (Si2H6), and can efficiently generate the target product through radical coupling reactions. Furthermore, the presence of hydrogen provides stable H· radicals, inhibiting silicon deposition, regulating the reaction pathway, and suppressing the generation of byproducts. In addition, hydrogen, as both a carrier gas and a reactant gas, can regulate the thermal effects of the reaction system, preventing localized overheating or excessive reaction during the reaction.

[0023] 2. In this invention, the plasma reactor generates a gentler electric field gradient after power is applied, effectively avoiding localized arcing and overheating. The resulting annular discharge region restricts plasma diffusion, improving energy density and electron collision efficiency. Furthermore, when the gas flows along the axial direction during the reaction, the coaxial structure reduces turbulence dead zones, lowers the probability of generating higher-order silanes (such as Si3H8), and improves the selectivity of silanes.

[0024] 3. Through the synergistic effect of the innovative coaxial ring electrode structure and high-frequency pulsed DC power supply, a maximum single-pass conversion rate of 70% for silane and a selectivity of 88% for silane were achieved under normal pressure conditions of 60~100℃, and the energy consumption was significantly reduced compared to the traditional method.

[0025] 4. The reaction has a fast reaction rate. Combined with a three-stage purification system of cold trap-adsorption-distillation, it can achieve deep removal of SiH4, N2, O2, CO2, H2 and higher silanes. It can obtain electronic grade silane with a purity ≥5N (impurities <0.5 ppm) in one step, which solves the problems of complex process and low selectivity in the existing technology. It is suitable for continuous large-scale production of silane. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of an apparatus for the continuous synthesis of silane via a discharge reaction.

[0027] Figure 2 This is a schematic diagram of a coaxial ring electrode structure.

[0028] Among them: 1. Silane cylinder, 2. Hydrogen cylinder, 3. Hydrogen flow meter, 4. Silane flow meter, 5. First buffer tank, 6. Plasma reactor, 6-1. Heat exchange jacket, 6-2. Annular electrode anode, 6-3. Annular electrode cathode, 7. Second buffer tank, 8. Vacuum pump, 9. Cold trap, 10. Compressor, 11. Adsorption tower, 12. Filter tank, 13. First-stage distillation tower, 14. Second-stage distillation tower. Detailed Implementation

[0029] The present application will be further described in detail below with reference to the embodiments.

[0030] like Figure 1 , 2As shown, an apparatus for the continuous synthesis of silane via discharge reaction includes a plasma reactor 6, an adsorption tower 11, and two distillation towers. The plasma reactor 6 contains an annular anode 6-2 and an annular cathode 6-3, which are coaxially arranged. A heat exchange jacket 6-1 is installed outside the plasma reactor 6. The upper part of the plasma reactor 6 is connected to a first buffer tank 5, followed by connections to a silane cylinder 1 and a hydrogen cylinder 2. A silane flow meter 4 is installed between the first buffer tank 5 and the silane cylinder 1, and a hydrogen flow meter 3 is installed between the first buffer tank 5 and the hydrogen cylinder 2. One branch of the bottom of the plasma reactor 6 connects to a second buffer tank 7 and a vacuum pump 8, while another branch connects to the top of the adsorption tower 11 via a cold trap 9 and a compressor 10. The bottom of the adsorption tower 11 is connected to the middle of the first distillation tower 13 via a filter tank 12. The top of the first distillation tower 13 is connected to a vent pipe, and its bottom is connected to the middle of the second distillation tower 14. All components are connected via pipes and valves.

[0031] The flow rate of hydrogen flow meter 3 and silane flow meter 4 is preferably 0~500 mL / min; the first buffer tank 5 and the second buffer tank 7 are equipped with pressure sensors, preferably with a range of 0~0.3 MPa; the anode material is preferably a molybdenum-doped graphene-silicon carbide hollow electrode with a wall thickness of 5 mm and an outer diameter of 30~50 mm; the cathode material is preferably a Hastelloy C-276 hollow electrode with a wall thickness of 5 mm and an outer diameter of 10~20 mm; the inner wall of the plasma reactor 6 is equipped with temperature and pressure sensors, preferably with a temperature sensor range of 0~200 ℃ and a pressure sensor range of 0~0.30 MPa; the pumping speed of the vacuum pump 8 is preferably 3~5 m. 3 / h, with an ultimate vacuum reaching 5 Pa under absolute pressure; the cold trap 9 is equipped with a temperature sensor and a cooling coil, with the lower end of the coil being the cooling liquid inlet and the upper end being the cooling liquid outlet; the temperature sensor's range is preferably -50~100 ℃; the compressor 10 has an adjustable pressure range of 0~1 MPa; the adsorption tower 11 is preferably made of 316L stainless steel, with an inner diameter preferably of 30~50 mm; the top of the adsorption tower 11 is equipped with an openable and closable cover for filling the adsorbent, which is preferably 5A molecular sieve, activated alumina, or color-changing silica gel; the filter element in the filter tank 12 has a pore size preferably of 0.1 μm; the two distillation towers are preferably made of 316L stainless steel, with an inner diameter preferably of 10~15 mm and a tower height of 1~3 m. The first distillation tower 13 and the second distillation tower 14 use Sulzer CY700 type stainless steel structured packing, with a specific surface area ≥700 m² / m³ and a theoretical plate number ≥20 plates / m.

[0032] Example 1 Combined with appendix Figure 1A method for the continuous synthesis of silane via discharge reaction, using silane as a raw material and H2 as a carrier gas, synthesizes silane via discharge under atmospheric pressure, and obtains 5N electronic-grade silane after passing through a cold trap, adsorption tower, and distillation tower. The method includes the following steps: Step 1: System evacuation. Start vacuum pump 6 and evacuate the system to an absolute pressure of 5 Pa to ensure that the reaction system is in an oxygen-free environment and to avoid interference from impurities.

[0033] Step 2: Preheat the reactor. Circulate heat transfer oil into the heat exchange jacket 4-1 to stabilize the temperature inside the reactor at 80℃.

[0034] Step 3: Raw material mixing. Silane and hydrogen are introduced into methane cylinder 1 and hydrogen cylinder 2 respectively, with the flow ratio controlled at 1:3 by mass flow meters F1 and F2, and the total gas flow rate at 120 mL / min. The mixed gas then enters buffer tank 3 for thorough mixing.

[0035] Step 4: Plasma reaction. The mixed gas is introduced into plasma reactor 4, and the pressure inside the reactor is controlled at 0.010 MPa. A high-frequency pulsed DC power supply with a frequency of 5 kHz and a voltage of 12 kV is applied to form a stable annular discharge region.

[0036] Step 5: Removal of byproducts in the cold trap. After the reaction, the gas enters the cold trap 7, and the temperature of the cold trap is set to 0°C. The ethylene glycol-water mixture (volume ratio 1:1) is circulated through the cooling coil to condense and remove higher-order silanes such as Si3H8.

[0037] Step 6: Adsorption and purification. The remaining gas is pressurized to 0.5 MPa by compressor 8 and enters adsorption tower 9 with an inner diameter of 40 mm and 5A molecular sieve as adsorbent to remove trace amounts of moisture and CO2. The gas exiting the adsorption tower passes through filter tank 10 to prevent particulate matter from entering the distillation tower.

[0038] Step 7: Distillation purification. The gas enters distillation column 11 (2 m high, 12 mm inner diameter, filled with Sulzer CY700 structured packing), operating at a pressure of 0.2 MPa, with a top temperature of -10℃, a bottom temperature of 10℃, and a condenser temperature of -30℃. A total reflux mode is used. Unreacted SiH4 and H2 at the top are returned to buffer tank 3 for recycling via valve K11. The bottom of the column is verified by gas chromatography-mass spectrometry (GC-MS) to obtain electronic-grade silane (Si2H6) with a purity of 5N (≥99.999%).

[0039] Example 2 Combined with appendix Figure 1 Based on Example 1, the key parameters are adjusted, and the specific implementation steps are as follows: Step 1: Evacuate the system. Start vacuum pump 6 and evacuate the system to an absolute pressure of 5 Pa to ensure that the reaction system is free of oxygen and other impurities.

[0040] Step 2: Preheat the reactor. Circulate heat transfer oil into the heat exchange jacket 4-1 to precisely control the reactor temperature at 90 ℃.

[0041] Step 3: Raw material mixing. Control the flow ratio of silane to hydrogen to be 1:4, and the total gas flow rate to be 150 mL / min.

[0042] Step 4: Plasma reaction. Introduce the feed gas; the reactor pressure is approximately 0.012 MPa. Adjust the spacing between the coaxial annular electrodes to 12 mm, ensuring the anode and cathode are coaxially aligned. Apply a high-frequency pulsed DC power supply with a frequency of 8 kHz and a voltage of 15 kV.

[0043] Step 5: Cold trap removal of byproducts. Cold trap 7 is maintained at 0 °C. Higher-order silanes (Si3H8, Si4H...) are removed... 10 Condensation efficiency > 98%, residual amount < 0.1%.

[0044] Step 6: Adsorption purification. Compressor 8 pressurizes the gas to 0.6 MPa. The adsorption tower 9 is filled with a composite adsorbent of 5A molecular sieve and activated alumina (mass ratio 3:1), increasing the adsorption capacity by 30%. After passing through a 0.05 μm filter canister 10, the outlet gas has a moisture content of <0.5 ppm and a CO2 content of <1 ppm.

[0045] Step 7: Distillation purification. Distillation column 11 operates at a pressure of 0.25 MPa, with a top temperature of -15°C, a bottom temperature of 15°C, and a condenser temperature of -35°C. In total reflux mode, the unreacted gases (SiH4 and H2) at the top of the column are recycled at a rate >95%, and silane with a purity of 5N is obtained at the bottom of the column. Verification by gas chromatography-mass spectrometry (GC-MS) shows that the total impurity content is <0.5 ppm.

[0046] Example 3 Combined with appendix Figure 1 To address the needs of small-scale production, the parameters are adjusted as follows: Step 1: Evacuate the system. Evacuate to an absolute pressure of 5 Pa.

[0047] Step 2: Preheat the reactor. Set the reactor temperature to 70 °C using a heat exchange jacket.

[0048] Step 3: Raw material mixing. The flow ratio of silane to hydrogen is 1:2, and the total gas flow rate is 80 mL / min.

[0049] Step 4: Plasma reaction. The reaction pressure within the plasma is approximately 0.07 MPa. The electrode spacing is adjusted to 18 mm, and the anode and cathode are arranged coaxially. A low-frequency DC pulse (frequency 3 kHz, voltage 8 kV) is used.

[0050] Step 5: Remove byproducts using the cold trap. The temperature of the cold trap 7 is 0 ℃.

[0051] Step 6: Adsorption and purification. The compressor is pressurized to 0.3 MPa, and the adsorption tower 9 is filled with color-changing silica gel. The moisture adsorption capacity reaches 5%, and the CO2 removal rate is >90%.

[0052] Step 7: Distillation purification. Distillation column 11 operates at a pressure of 0.15 MPa, with a top temperature of -5 ℃, a bottom temperature of 8 ℃, and a condenser temperature of -25 ℃. The purity of the silane at the bottom of the column is 5N, verified by gas chromatography-mass spectrometry (GC-MS) to be <1 ppm, suitable for photovoltaic-grade silicon film preparation.

[0053] The reaction conditions of each embodiment are shown in Table 1.

[0054] Table 1. Reaction status of each embodiment

[0055] In summary, this invention provides an apparatus and method for the continuous synthesis of silane via discharge reaction. It is the first to employ a coaxial ring electrode structure combined with a pulsed DC power supply, utilizing silane and hydrogen gas to synthesize silane under ambient pressure. The single-pass conversion rate of silane and the selectivity of silane reach 70% and 88%, respectively. The crude gas, after condensation, adsorption, and purification, yields electronic-grade silane with a purity of 5N, suitable for industrial production.

[0056] The above embodiments are not limiting embodiments of the present invention. Any modifications, improvements or equivalent variations made in accordance with the spirit and principles of the present invention shall be within the technical scope of the present invention.

Claims

1. An apparatus for the continuous synthesis of silane via a discharge reaction, characterized in that, The plasma reactor (6) includes an adsorption tower (11) and two distillation towers. The plasma reactor (6) is equipped with an annular anode (6-2) and an annular cathode (6-3), which are coaxially arranged. A heat exchange jacket (6-1) is installed outside the plasma reactor (6). The upper part of the plasma reactor (6) is connected to a first buffer tank (5), followed by a silane cylinder (1) and a hydrogen cylinder (2). A silane flow meter (4) is installed between the first buffer tank (5) and the silane cylinder (1). A hydrogen flow meter (3) is installed between the first buffer tank (5) and the hydrogen cylinder (2); one branch of the plasma reactor (6) is connected to the second buffer tank (7) and the vacuum pump (8), and the other branch is connected to the top of the adsorption tower (11) via the cold trap (9) and the compressor (10); the bottom of the adsorption tower (11) is connected to the middle of the first distillation tower (13) via the filter tank (12), the top of the first distillation tower (13) is connected to the vent pipe, and the bottom is connected to the middle of the second distillation tower (14). The components are connected by pipes and valves.

2. The apparatus according to claim 1, characterized in that, The range of the hydrogen flow meter (3) and the silane flow meter (4) is 0~500 mL / min.

3. The apparatus according to claim 1, characterized in that, The first buffer tank (5) and the second buffer tank (7) are equipped with pressure sensors with a range of 0~0.3 MPa.

4. The apparatus according to claim 1, characterized in that, The anode material is a molybdenum-doped graphene-silicon carbide hollow electrode with a wall thickness of 5 mm and an outer diameter of 30~50 mm; the cathode material is a Hastelloy C-276 hollow electrode with a wall thickness of 5 mm and an outer diameter of 10~20 mm.

5. The apparatus according to claim 1, characterized in that, The inner wall of plasma reactor 6 is equipped with temperature sensors and pressure sensors. The temperature sensors have a range of 0~200 ℃, and the pressure sensors have a range of 0~0.30 MPa.

6. The apparatus according to claim 1, characterized in that, The vacuum pump (8) has a pumping speed of 3~5 m. 3 / h, the ultimate vacuum can reach 5 Pa under absolute pressure.

7. The apparatus according to claim 1, characterized in that, The cold trap (9) is equipped with a temperature sensor and a cold liquid coil. The lower end of the coil is the cold liquid inlet, and the upper end is the cold liquid outlet. The temperature sensor has a range of -50~100 ℃.

8. The apparatus according to claim 1, characterized in that, The compressor (10) has an adjustable pressure range of 0~1 MPa; the adsorption tower (11) is made of 316L stainless steel with an inner diameter of 30~50 mm; the top of the adsorption tower (11) is equipped with an openable cover for filling with adsorbent, which is 5A molecular sieve, activated alumina or color-changing silica gel; the filter element in the filter tank (12) has a pore size of 0.1 μm; the two distillation towers are made of 316L stainless steel with an inner diameter of 10~15 mm and a tower height of 1~3 m; the first distillation tower (13) and the second distillation tower (14) are equipped with Sulzer CY700 stainless steel structured packing with a specific surface area ≥700 m² / m³ and a theoretical plate number ≥20 plates / m.

9. A method for the continuous synthesis of silane via a discharge reaction, characterized in that, Using silane as a raw material and H2 as a carrier gas, ethylsilane is synthesized by discharge under normal pressure. After passing through a cold trap, adsorption tower, and distillation tower, 5N electronic-grade ethylsilane is obtained, including the following steps: Step 1: Evacuate the apparatus for the continuous synthesis of silane via discharge reaction to an absolute pressure of 5-10 Pa; Step 2: Preheat the plasma reactor to 60~100 ℃; Step 3: Mix silane and hydrogen by introducing them into the first buffer tank through a flow meter; Step 4: The mixed gas is introduced into the plasma reactor for reaction at a temperature of 60~100℃; Step 5: The reaction product enters a cold trap to remove some of the higher-order silanes; Step 6: The crude silane gas after the cold trap is drawn to the adsorption tower by the compressor for adsorption, removing moisture and some carbon dioxide; Step 7: The adsorbed gas enters a distillation column for distillation to obtain electronic-grade silane with a purity of 5N or higher.

10. The method according to claim 9, characterized in that, The flow ratio of silane to hydrogen is 1:1~5, and the total gas flow rate is 50~200 mL / min. The reactor temperature is controlled at a certain temperature node between 60~100℃ through a heat exchange jacket. The plasma reactor is equipped with a high-frequency pulsed DC power supply with a frequency of 1~10 kHz and a voltage of 5~20 kV. The reaction pressure range in the reactor is 0.001~0.10 MPa. The temperature of the cold trap is 0℃, and higher-order silanes with silicon atomic lengths greater than 2 are removed. The distillation columns adopt continuous distillation, with an operating pressure of 0.1~0.3 MPa. The top temperature of the first distillation column 13 is -40~-20℃, the bottom temperature is 40~60℃, and the condenser temperature is -40~-20℃. The top temperature of the second distillation column 14 is -10~10℃, the bottom temperature is 10~30℃, and the condenser temperature is -20~0℃.

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