Polycrystalline silicon cold hydrogenation reaction system and reaction method

Abstract

The invention provides a polycrystalline silicon cold hydrogenation reaction system and method. The reaction system comprises a cold hydrogenation reactor, a hydrogen supplementing compressor, a silicon powder high-pressure hopper, a silicon powder high-pressure hopper filter, a recycled hydrogen filter, an air cooler, a first cooler, a second cooler, a heat exchanger and a third cooler. According to the reaction system, hydrogen for feeding cold hydrogenated silicon powder can be recycled, so that the discharge amount of hydrogen in the cold hydrogenation process is reduced, the consumption of hydrogen in polycrystalline silicon production is reduced, and the load of a waste gas leaching procedure is reduced; the consumption of a cooling medium can be reduced, the energy consumption of a reaction system is reduced, and the production cost is saved.

Description

Technical Field

[0001] The invention relates to a polysilicon cold hydrogenation reaction system and a reaction method, belonging to the technical field of chemical separation. Background Art

[0002] In the semiconductor and solar photovoltaic industries, polysilicon is a key raw material for manufacturing high-purity silicon materials. In the polysilicon production process, cold hydrogenation is a key step. A catalyst is mainly used to cause silicon powder, hydrogen and silicon tetrachloride to undergo cold hydrogenation reaction at high temperature to obtain reaction tail gas including trichlorosilane and hydrogen. At present, the reaction tail gas formed after the cold hydrogenation reaction is mainly dusted and cooled in one step using a cooling medium to obtain circulating hydrogen and chlorosilane solution in the reaction tail gas. This method is prone to increase the consumption of cooling medium and increase the energy consumption of the reaction system.

[0003] And in the process of feeding silicon powder, the silicon powder high-pressure hopper needs to accept silicon powder again after the silicon powder is pushed out. In this process, the hydrogen in the silicon powder high-pressure hopper needs to be discharged to reduce the pressure of the silicon powder high-pressure hopper from high pressure to slightly positive pressure. The discharged hydrogen is sent to the waste gas leaching process for treatment and then discharged into the atmosphere. However, the direct discharge of hydrogen will cause great waste. At the same time, a large amount of hydrogen will also increase the load of the waste gas leaching process and increase production costs. Summary of the invention

[0004] The present invention provides a polysilicon cold hydrogenation reaction system, which can recycle hydrogen fed into cold hydrogenated silicon powder, thereby reducing the emission of hydrogen during the cold hydrogenation process, reducing the consumption of hydrogen in polysilicon production, and reducing the load of the waste gas elution process; it can also reduce the consumption of cooling medium, reduce the energy consumption of the reaction system, and save production costs.

[0005] The present invention provides a polysilicon cold hydrogenation reaction method, which is carried out using the above-mentioned reaction system. The reaction method can recycle the hydrogen fed to the cold hydrogenated silicon powder, thereby reducing the emission of hydrogen during the cold hydrogenation process, reducing the consumption of hydrogen in the polysilicon production, and reducing the load of the waste gas elution process; it can also reduce the consumption of cooling medium, reduce the energy consumption of the reaction system, and save production costs; it can also reduce the consumption of cooling medium, reduce the energy consumption of the reaction system, save production costs, and help improve the competitiveness of the enterprise.

[0006] The present invention provides a polysilicon cold hydrogenation reaction system, which includes a cold hydrogenation reactor, a hydrogen supplement compressor, a silicon powder high-pressure hopper, a silicon powder high-pressure hopper filter, a hydrogen recovery filter, an air cooler, a first cooler, a second cooler, a heat exchanger and a third cooler;

[0007] The outlet of the supplementary hydrogen compressor is connected to the pressurized hydrogen inlet of the silicon powder high-pressure hopper, the silicon powder outlet of the silicon powder high-pressure hopper is connected to the silicon powder inlet of the cold hydrogenation reactor, the hydrogen outlet of the silicon powder high-pressure hopper is connected to the hydrogen inlet of the silicon powder high-pressure hopper filter, the silicon powder-containing hydrogen outlet of the silicon powder high-pressure hopper filter is connected to the hydrogen inlet of the hydrogen recovery filter, and the hydrogen recovery filter has a hydrogen recovery outlet;

[0008] The outlet of the cold hydrogenation reactor is communicated with the inlet of the air cooler, the outlet of the air cooler is communicated with the inlet of the first cooler, the gas phase outlet of the first cooler is communicated with the inlet of the second cooler, the gas phase outlet of the second cooler is communicated with the heat source inlet of the heat exchanger, the heat source outlet of the heat exchanger is communicated with the inlet of the third cooler, and the gas phase outlet of the third cooler is communicated with the cold source medium inlet of the heat exchanger;

[0009] The cooling medium in the first cooler is circulating water, the cooling medium in the second cooler is at least one of chilled water, ethylene glycol, and -25°C Freon, and the cooling medium in the third cooler is -45°C Freon.

[0010] The polysilicon cold hydrogenation reaction system as described above, wherein, if the pressure of the recovered hydrogen outlet is greater than the inlet pressure of the supplementary hydrogen compressor, the recovered hydrogen outlet is connected to the inlet of the supplementary hydrogen compressor; or,

[0011] If the pressure of the recovered hydrogen outlet is less than or equal to the inlet pressure of the supplementary hydrogen compressor, the recovered hydrogen outlet is connected to the hydrogen-containing tail gas recovery system.

[0012] In the polysilicon cold hydrogenation reaction system as described above, the silicon powder high-pressure hopper filter is located at the top of the silicon powder high-pressure hopper, and the gas outlet of the silicon powder high-pressure hopper is connected to the gas inlet of the silicon powder high-pressure hopper filter.

[0013] The polysilicon cold hydrogenation reaction system as described above, further comprises a silicon powder low-pressure hopper, wherein the outlet of the silicon powder low-pressure hopper is connected to the silicon powder inlet of the silicon powder high-pressure hopper.

[0014] The polysilicon cold hydrogenation reaction system as described above, further includes a silicon powder low-pressure hopper filter, the gas outlet of the silicon powder low-pressure hopper is connected to the gas inlet of the silicon powder low-pressure hopper filter, and the silicon powder outlet of the silicon powder low-pressure hopper is connected to the silicon powder inlet of the silicon powder high-pressure hopper.

[0015] The polysilicon cold hydrogenation reaction system as described above, wherein the silicon powder low-pressure hopper filter is located at the top of the silicon powder low-pressure hopper; and / or,

[0016] The silicon powder low-pressure hopper is located on the top of the silicon powder high-pressure hopper.

[0017] The polysilicon cold hydrogenation reaction system as described above, further includes a coarse separation tower, wherein the liquid phase outlet of the first cooler, the liquid phase outlet of the second cooler, the liquid phase outlet of the third cooler and the liquid phase outlet of the heat exchanger are respectively connected to the inlet of the coarse separation tower.

[0018] The polysilicon cold hydrogenation reaction system as described above, wherein the coarse fractionation tower comprises a reboiler, and the reaction tail gas is connected to the reboiler; and / or,

[0019] Also includes a first preheater and a second preheater;

[0020] The reaction tail gas is connected to the heat source inlet of the first preheater, the cold source outlet of the heat exchanger is connected to the cold source inlet of the first preheater, the heat source outlet of the first preheater is connected to the heat source inlet of the second preheater, the silicon tetrachloride outlet of the coarse fractionation tower is connected to the cold source inlet of the second preheater, and the heat source outlet of the second preheater is connected to the inlet of the air cooler.

[0021] The polysilicon cold hydrogenation reaction system as described above, wherein, further comprises a heating vaporization unit, wherein the cold source outlet of the first preheater is connected to the inlet of the heating vaporization unit, the cold source outlet of the second preheater is connected to the inlet of the heating vaporization unit, and the outlet of the heating vaporization unit is connected to the cold hydrogenation reactor.

[0022] The present invention also provides a polysilicon cold hydrogenation reaction method, wherein the method is carried out using the polysilicon cold hydrogenation reaction system as described above.

[0023] The polysilicon cold hydrogenation reaction system of the present invention can reduce the emission of hydrogen during the cold hydrogenation process, reduce the consumption of hydrogen in the production of polysilicon, reduce the load of the waste gas elution process, and reduce the consumption of cooling medium, reduce the energy consumption of the reaction system, and save production costs through the organic connection of the cold hydrogenation reactor, the replenishing hydrogen compressor, the silicon powder high-pressure hopper, the silicon powder high-pressure hopper filter, the hydrogen recovery filter, the air cooler, the first cooler, the second cooler, the heat exchanger and the third cooler.

[0024] The polysilicon cold hydrogenation reaction method of the present invention is carried out through the above-mentioned polysilicon cold hydrogenation reaction system. The reaction method can reduce the emission of hydrogen during the cold hydrogenation process, reduce the consumption of hydrogen in polysilicon production, and reduce the load of the waste gas elution process. It can also reduce the consumption of cooling medium, reduce the energy consumption of the reaction system, and save production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present invention or related technologies. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 Schematic diagram of a hydrogen recovery system for feeding polysilicon cold hydrogenated silicon powder in some embodiments of the present invention;

[0027] Figure 2 Schematic diagram of a system for processing tail gas from a cold hydrogenation reaction of polysilicon in some embodiments of the present invention.

[0028] Description of reference numerals:

[0029] 1: Heating and vaporizing unit; 2: Cold hydrogenation reactor; 3: Washing and cooling unit; 4: Coarse fractionation tower; 5: Reboiler; 6: First preheater; 7: Second preheater; 8: Air cooler; 9: First cooler; 10: Second cooler; 11: Heat exchanger; 12: Third cooler; 13: Detection unit; 14: Pressure swing adsorption unit;

[0030] 21: Silicon powder high pressure hopper; 22: Silicon powder high pressure hopper filter; 23: Hydrogen recovery filter; 24: Silicon powder low pressure hopper filter; 25: Silicon powder low pressure hopper. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Figure 1 Schematic diagram of a hydrogen recovery system for feeding polysilicon cold hydrogenated silicon powder in some embodiments of the present invention; Figure 2 Schematic diagram of a system for treating tail gas from a polysilicon cold hydrogenation reaction in some embodiments of the present invention. Figure 1 and Figure 2 As shown, the first aspect of the present invention provides a polysilicon cold hydrogenation reaction system, comprising: a cold hydrogenation reactor 2, a supplementary hydrogen compressor, a silicon powder high-pressure hopper 21, a silicon powder high-pressure hopper filter 22, a hydrogen recovery filter 23, an air cooler 8, a first cooler 9, a second cooler 10, a heat exchanger 11 and a third cooler 12;

[0033] The outlet of the supplementary hydrogen compressor is connected to the pressurized hydrogen inlet of the silicon powder high-pressure hopper 21, the silicon powder outlet of the silicon powder high-pressure hopper 21 is connected to the silicon powder inlet of the cold hydrogenation reactor 2, the hydrogen outlet of the silicon powder high-pressure hopper 21 is connected to the hydrogen inlet of the silicon powder high-pressure hopper filter 22, the silicon powder-containing hydrogen outlet of the silicon powder high-pressure hopper filter 22 is connected to the hydrogen inlet of the recovery hydrogen filter 23, and the recovery hydrogen filter 23 has a recovery hydrogen outlet;

[0034] The outlet of the cold hydrogenation reactor 2 is communicated with the inlet of the air cooler 8, the outlet of the air cooler 8 is communicated with the inlet of the first cooler 9, the gas phase outlet of the first cooler 9 is communicated with the inlet of the second cooler 10, the gas phase outlet of the second cooler 10 is communicated with the heat source inlet of the heat exchanger 11, the heat source outlet of the heat exchanger 11 is communicated with the inlet of the third cooler 12, and the gas phase outlet of the third cooler 12 is communicated with the cold source medium inlet of the heat exchanger 11;

[0035] The cooling medium in the first cooler is circulating water, the cooling medium in the second cooler is at least one of chilled water, ethylene glycol, and -25°C Freon, and the cooling medium in the third cooler is -45°C Freon.

[0036] In the present invention, a hydrogen compressor is used to transport the compressed hydrogen to the silicon powder high-pressure hopper 21, so that the silicon powder in the silicon powder high-pressure hopper 21 is transported to the cold hydrogenation reactor 2 by the compressed hydrogen pressure. When the silicon powder in the silicon powder high-pressure hopper 21 is emptied, it is necessary to receive silicon powder again. In this process, the pressure in the silicon powder high-pressure hopper 21 (in some embodiments, the pressure in the silicon powder high-pressure hopper 21 can be 2.6-3.8MPaG) needs to be relieved from high pressure to slightly positive pressure. At this time, the silicon powder-containing hydrogen in the silicon powder high-pressure hopper 21 is output through the hydrogen outlet of the silicon powder high-pressure hopper 21, and then The hydrogen inlet of the silicon powder high-pressure hopper filter 22 enters the silicon powder high-pressure hopper filter 22 for the first filtering treatment to filter out large particles of silicon powder in the silicon powder-containing hydrogen, thereby obtaining intermediate hydrogen; then the intermediate hydrogen is output through the silicon powder-containing hydrogen outlet of the silicon powder high-pressure hopper filter 22, and enters the recovery hydrogen filter 23 through the inlet of the recovery hydrogen filter 23, and the intermediate hydrogen undergoes the second filtering treatment in the recovery hydrogen filter 23 to further filter and remove small particles of silicon powder in the hydrogen, thereby obtaining recovered hydrogen, and the obtained recovered hydrogen is output through the recovery hydrogen outlet of the recovery hydrogen filter 23.

[0037] Then, silicon powder, catalyst, hydrogen, silicon tetrachloride and silicon powder are subjected to cold hydrogenation reaction in cold hydrogenation reactor 2 to obtain polysilicon cold hydrogenation reaction tail gas including trichlorosilane, silicon tetrachloride and hydrogen, and the reaction tail gas is output through the outlet of cold hydrogenation reactor 2, firstly enters air cooler 8 through the inlet of air cooler 8 for air cooling treatment, and then is output from the outlet of air cooler 8 after the temperature of the reaction tail gas is preliminarily reduced; the reaction tail gas output from the outlet of air cooler 8 enters the first cooler 9 through the inlet of the first cooler 9 to perform a first cooling treatment on the reaction tail gas, further reducing the temperature of the reaction tail gas, and reacting The first part of the chlorosilane in the reaction tail gas is converted into a chlorosilane solution, the chlorosilane solution is output from the liquid phase outlet of the first cooler 9, and the reaction tail gas is output from the gas phase outlet of the first cooler 9; then the reaction tail gas output from the gas phase outlet of the first cooler 9 enters the second cooler 10 through the inlet of the second cooler 10 to perform a second cooling treatment on the reaction tail gas, and the temperature of the reaction tail gas is reduced again, and the second part of the chlorosilane in the reaction tail gas is converted into a chlorosilane solution, the chlorosilane solution is output from the liquid phase outlet of the second cooler 10, and the reaction tail gas is output from the gas phase outlet of the second cooler 10; then The reaction tail gas output from the gas phase outlet of the second cooler 10 enters the heat exchanger 11 through the heat source inlet of the heat exchanger 11 for heat exchange treatment and enters the third cooler 12 through the inlet of the third cooler 12 for third cooling treatment, wherein the reaction tail gas output from the heat source outlet of the heat exchanger 11 enters the third cooler 12 through the inlet of the third cooler 12 for third cooling treatment, the reaction tail gas temperature is reduced again, and the third part of the chlorosilane in the reaction tail gas is converted into a chlorosilane solution, the chlorosilane solution is output from the liquid phase outlet of the third cooler 12, and the circulating hydrogen is output from the third cooler The circulating hydrogen output from the gas phase outlet of the third cooler 12 enters the heat exchanger 11 through the cold source medium inlet of the heat exchanger 11 for heat exchange treatment, so that the reaction tail gas output from the gas phase outlet of the second cooler 10 is cooled and the fourth part of chlorosilane in the reaction tail gas is converted into chlorosilane solution. In the heat exchanger 11, the reaction tail gas can also preheat the circulating hydrogen to increase the temperature of the circulating hydrogen to obtain the first intermediate circulating hydrogen. The chlorosilane solution is output from the liquid phase outlet of the heat exchanger 11, and the first intermediate circulating hydrogen is output from the cold source outlet of the heat exchanger 11.

[0038] The present invention sequentially uses a silicon powder high-pressure hopper filter 22 and a hydrogen recovery filter 23 to process the silicon powder-containing hydrogen output from the silicon powder high-pressure hopper 21, which can reduce the content and particle size of silicon powder in the silicon powder-containing hydrogen, thereby obtaining recycled hydrogen that can be recycled again. The hydrogen recovery system can recycle the hydrogen fed to the cold hydrogenated silicon powder, reduce the emission of hydrogen during the cold hydrogenation process, reduce the consumption of hydrogen in the production of polysilicon, and reduce the load of the waste gas washing process, thereby reducing production costs. At the same time, the reaction tail gas is cooled and treated multiple times by the treatment system of the air cooler 8, the first cooler 9, the second cooler 10, the heat exchanger 11, and the third cooler 12 to obtain a chlorosilane solution and circulating hydrogen, which can reduce the consumption of the cooling medium, reduce the energy consumption of the reaction system, save production costs, and help improve the competitiveness of the enterprise.

[0039] In the present invention, the recovered hydrogen can be recovered in stages according to the pressure of the recovered hydrogen, thereby further improving the utilization rate of the recovered hydrogen and saving the consumption of hydrogen.

[0040] Exemplarily, in some embodiments of the present invention, if the pressure of the outlet of the recovered hydrogen is greater than the inlet pressure of the supplemental hydrogen compressor, the outlet of the recovered hydrogen is connected to the inlet of the supplemental hydrogen compressor.

[0041] Specifically, if the pressure of the recovered hydrogen outlet is greater than the inlet pressure of the hydrogen replenishment compressor, the recovered hydrogen is output through the recovered hydrogen outlet, enters the hydrogen replenishment compressor air inlet buffer tank, and after being compressed by the hydrogen replenishment compressor, re-enters the cold hydrogenation reaction system for recycling.

[0042] In some embodiments of the present invention, if the pressure of the recovered hydrogen outlet is less than or equal to the inlet pressure of the supplementary hydrogen compressor, the recovered hydrogen outlet is connected to the hydrogen-containing tail gas recovery system.

[0043] Specifically, if the pressure of the recovered hydrogen outlet is ≤ the inlet pressure of the hydrogen replenishment compressor, the recovered hydrogen is output through the recovered hydrogen outlet, enters the hydrogen-containing tail gas recovery system, and is compressed and pressurized by the hydrogen-containing tail gas recovery system compressor before being sent to the hydrogen replenishment compressor inlet buffer tank.

[0044] In a specific embodiment, the inlet pressure of the hydrogen supplement compressor is 0.6 MPaG. If the pressure of the recovered hydrogen outlet is greater than 0.6 MPaG, the recovered hydrogen outlet is connected to the hydrogen inlet of the hydrogen supplement compressor intake buffer tank;

[0045] If the pressure of the recovered hydrogen outlet is less than or equal to 0.6 MPaG, the recovered hydrogen outlet is connected to the hydrogen-containing tail gas recovery system.

[0046] In some embodiments, when the silicon powder high-pressure hopper 21 is replaced with nitrogen or the silicon powder high-pressure hopper filter 22 is replaced with nitrogen, hydrogen tail gas containing nitrogen (nitrogen-containing replaced hydrogen) will be discharged, and the nitrogen-containing replaced hydrogen will not be recovered, and the pressure will not be controlled, but will be directly discharged to the waste gas network for treatment.

[0047] In some embodiments of the present invention, the hydrogen recovery system further includes a silicon powder low-pressure hopper 25 , and a silicon powder outlet of the silicon powder low-pressure hopper 25 is connected to a silicon powder inlet of the silicon powder high-pressure hopper 21 .

[0048] Specifically, the silicon powder is outputted through the silicon powder outlet of the silicon powder low-pressure hopper 25 , and enters the silicon powder high-pressure hopper 21 through the silicon powder inlet of the silicon powder high-pressure hopper 21 .

[0049] The present invention utilizes the silicon powder low-pressure hopper 25 to store silicon powder, which helps to control the silicon powder feed amount of the silicon powder high-pressure hopper 21, thereby better controlling the cold hydrogenation reaction and promoting the generation of trichlorosilane.

[0050] In some embodiments of the present invention, the hydrogen recovery system also includes a silicon powder low-pressure hopper filter 24, the gas outlet of the silicon powder low-pressure hopper 25 is connected to the gas inlet of the silicon powder low-pressure hopper filter 24, and the silicon powder outlet of the silicon powder low-pressure hopper 25 is connected to the silicon powder inlet of the silicon powder high-pressure hopper 21.

[0051] Specifically, the hydrogen containing silicon powder in the silicon powder low-pressure hopper 25 is output through the hydrogen containing silicon powder outlet of the silicon powder low-pressure hopper 25 , and is discharged after being filtered by the silicon powder low-pressure hopper filter 24 ; the silicon powder is output through the outlet of the silicon powder low-pressure hopper filter 24 , and enters the silicon powder low-pressure hopper 25 through the silicon powder inlet of the silicon powder low-pressure hopper 25 .

[0052] The present invention first uses the silicon powder low-pressure hopper filter 24 to filter the silicon powder in the air discharged from the silicon powder low-pressure hopper 25, which can reduce the content of silicon powder in the air discharged during the feeding process, improve the operating environment of the cold hydrogenation device, and reduce air pollution.

[0053] In some embodiments, an electric hoist or a pneumatic conveying device may be used to convey the silicon powder to the powder low-pressure hopper 5 .

[0054] In some embodiments of the present invention, the silicon powder low-pressure hopper filter 24 is located on the top of the silicon powder low-pressure hopper 25 .

[0055] Specifically, when the silicon powder low-pressure hopper filter 24 is located on the top of the silicon powder low-pressure hopper 25, the silicon powder flows through the silicon powder low-pressure hopper filter 24 under the action of gravity to the silicon powder low-pressure hopper 25 for storage.

[0056] In some embodiments of the present invention, the silicon powder low-pressure hopper 25 is located on the top of the silicon powder high-pressure hopper 21. The present invention utilizes the potential difference to transport the silicon powder, which helps to further save energy consumption.

[0057] Specifically, when the silicon powder low-pressure hopper 25 is located on the top of the silicon powder high-pressure hopper 21 , the silicon powder flows by gravity through the silicon powder low-pressure hopper 25 into the silicon powder high-pressure hopper 21 .

[0058] In some embodiments of the present invention, a coarse fractionation tower 4 is further included, and the liquid phase outlet of the first cooler 9, the liquid phase outlet of the second cooler 10, the liquid phase outlet of the third cooler 12 and the liquid phase outlet of the heat exchanger 11 are respectively connected to the inlet of the coarse fractionation tower 4.

[0059] In the present invention, the chlorosilane solution is outputted through the liquid phase outlet of the first cooler 9, the liquid phase outlet of the second cooler 10, the liquid phase outlet of the third cooler 12 and the liquid phase outlet of the heat exchanger 11 respectively, and enters the coarse fractionation tower 4 through the inlet of the coarse fractionation tower 4 for coarse fractionation treatment to obtain circulating silicon tetrachloride and crude trichlorosilane. The crude trichlorosilane can enter the subsequent distillation treatment, and the separated circulating silicon tetrachloride can participate in the cold hydrogenation reaction.

[0060] The present invention performs rough separation treatment on the chlorosilane solution entering the rough separation tower 4 through the inlet of the rough separation tower 4, and separates the chlorosilane solution into circulating silicon tetrachloride and crude trichlorosilane, so that the chlorosilane solution can be further utilized to further improve the utilization rate of resources.

[0061] In some embodiments of the present invention, the coarse fraction tower 4 includes a reboiler 5 , and the reaction tail gas is in communication with the reboiler 5 .

[0062] In the present invention, the reaction tail gas enters the reboiler 5 of the coarse fractionation tower 4 and serves as a heat source for the reboiler 5 to provide heat for the reboiler 5. After the heat is fully utilized, the reaction tail gas is output through the reboiler 5 to participate in the first preheating treatment.

[0063] The present invention uses the reaction tail gas as the heat source of the reboiler 5 to provide heat for the coarse fractionation tower 4, which can realize the heat utilization of the reaction tail gas and also reduce the temperature of the reaction tail gas, which helps to further reduce energy consumption and save production costs.

[0064] In some embodiments of the present invention, a first preheater 6 and a second preheater 7 are further included;

[0065] The reaction tail gas is connected to the heat source inlet of the first preheater 6, the cold source outlet of the heat exchanger 11 is connected to the cold source inlet of the first preheater 6, the heat source outlet of the first preheater 6 is connected to the heat source inlet of the second preheater 7, the silicon tetrachloride outlet of the coarse fractionation tower 4 is connected to the cold source inlet of the second preheater 7, and the heat source outlet of the second preheater 7 is connected to the inlet of the air cooler 8.

[0066] Specifically, the reaction tail gas enters the first preheater 6 through the heat source inlet of the first preheater 6, and the first intermediate circulating hydrogen output from the cold source outlet of the heat exchanger 11 enters the first preheater 6 through the cold source inlet of the first preheater 6. The reaction tail gas entering the first preheater 6 is used as a heat source to heat the first intermediate circulating hydrogen. After heating, the first intermediate reaction tail gas, chlorosilane solution and preheating circulating hydrogen are obtained. The first intermediate reaction tail gas is output through the heat source outlet of the first preheater 6, the chlorosilane solution is output through the liquid phase outlet of the first preheater 6, and the preheating circulating hydrogen is output through the circulating hydrogen outlet of the first preheater 6; the first intermediate reaction tail gas output from the heat source outlet of the first preheater 6 enters the second preheater 7 through the heat source inlet In the reactor 7, the chlorosilane solution outputted through the liquid phase outlet of the first preheater 6 enters the coarse fractionation tower 4 through the inlet of the coarse fractionation tower 4 for coarse fractionation to obtain the circulating silicon tetrachloride, and the circulating silicon tetrachloride is outputted from the silicon tetrachloride outlet of the coarse fractionation tower 4 through the cold source inlet of the second preheater 7 to enter the second preheater 7, and the first intermediate reaction tail gas entering the second preheater 7 is used as a heat source to heat the circulating silicon tetrachloride entering the second preheater 7, and after heating, the reaction tail gas, which has been cooled again, the chlorosilane solution and the preheated silicon tetrachloride are obtained, and the reaction tail gas, which has been cooled again, is outputted from the heat source outlet of the second preheater 7 and enters the air cooler 8 through the inlet of the air cooler 8 for air cooling treatment, and the obtained preheated silicon tetrachloride can be further preheated to participate in the cold hydrogenation reaction.

[0067] The present invention uses the reaction tail gas to perform a first preheating treatment in the first preheater 6 and a second preheating treatment in the second preheater 7 in sequence, thereby making full use of the heat of the reaction tail gas, saving energy consumption and reducing production costs.

[0068] In some embodiments of the present invention, the polysilicon cold hydrogenation reaction system also includes a heating vaporization unit 1, the cold source outlet of the first preheater 6 is connected to the inlet of the heating vaporization unit 1, the cold source outlet of the second preheater 7 is connected to the inlet of the heating vaporization unit 1, and the outlet of the heating vaporization unit 1 is connected to the cold hydrogenation reactor 2.

[0069] Specifically, the preheated circulating hydrogen is output through the cold source outlet of the first preheater 6, and enters the heating vaporization unit 1 through the inlet of the heating vaporization unit 1. The preheated silicon tetrachloride is output through the cold source outlet of the second preheater 7, and enters the heating vaporization unit 1 through the inlet of the heating vaporization unit 1. After the preheated circulating hydrogen and the preheated silicon tetrachloride are heated and vaporized in the heating vaporization unit 1, they are output through the outlet of the heating vaporization unit 1, enter the cold hydrogenation reactor 2 through the inlet of the cold hydrogenation reactor 2, and continue to participate in the cold hydrogenation reaction.

[0070] The present invention can realize resource recycling and save production costs by mixing preheated circulating hydrogen with preheated silicon tetrachloride to participate in cold hydrogenation reaction.

[0071] In some embodiments, the cold hydrogenation reaction system further includes a washing and cooling unit 3, a detection unit 13, and a pressure swing adsorption unit 14;

[0072] Among them, the outlet of the cold hydrogenation reactor 2 is connected to the inlet of the washing and cooling unit 3, the gas phase outlet of the washing and cooling unit 3 is connected to the reboiler 5 of the coarse fraction tower 4, the reboiler 5 is connected to the heat source inlet of the first preheater 6, the liquid phase outlet of the first preheater 6 is connected to the chlorosilane inlet of the coarse fraction tower 4, and the cold source outlet of the first preheater 6 is connected to the inlet of the heating vaporization unit 1; the heat source outlet of the first preheater 6 is connected to the heat source inlet of the second preheater 7, the circulating silicon tetrachloride outlet of the coarse fraction tower 4 is connected to the cold source inlet of the second preheater 7, the liquid phase outlet of the second preheater 7 is connected to the chlorosilane inlet of the coarse fraction tower 4, and the cold source outlet of the second preheater 7 is connected to the inlet of the heating vaporization unit 1; the heat source outlet of the second preheater 7 is connected to the inlet of the air cooler 8, the outlet of the air cooler 8 is connected to the inlet of the first cooler 9, and the liquid phase outlet of the first cooler 9 is connected to the The chlorosilane inlet of the coarse fractionation tower 4 is connected; the gas phase outlet of the first cooler 9 is connected to the inlet of the second cooler 10, and the liquid phase outlet of the second cooler 10 is connected to the chlorosilane inlet of the coarse fractionation tower 4; the gas phase outlet of the second cooler 10 is connected to the heat source inlet of the heat exchanger 11, the heat source outlet of the heat exchanger 11 is connected to the inlet of the third cooler 12, the liquid phase outlet of the third cooler 12 is connected to the chlorosilane inlet of the coarse fractionation tower 4, the gas phase outlet of the third cooler 12 is connected to the cold source inlet of the heat exchanger 11, the cold source outlet of the heat exchanger 11 is connected to the inlet of the detection unit 13, the outlet of the detection unit 13 is respectively connected to the inlet of the pressure swing adsorption unit 14 and the cold source inlet of the first preheater 6; the outlet of the pressure swing adsorption unit 14 is connected to the cold source inlet of the first preheater 6, and the outlet of the heating vaporization unit 1 is connected to the inlet of the cold hydrogenation reactor 2.

[0073] The second aspect of the present invention provides a polysilicon cold hydrogenation reaction method, which is performed using the polysilicon cold hydrogenation reaction system of the first aspect.

[0074] The reaction method can recycle the hydrogen fed to the cold hydrogenated silicon powder, thereby reducing the emission of hydrogen during the cold hydrogenation process, reducing the consumption of hydrogen in the production of polysilicon, and reducing the load of the waste gas elution process; it can also reduce the consumption of cooling medium, reduce the energy consumption of the reaction system, and save production costs; it can also reduce the consumption of cooling medium, reduce the energy consumption of the reaction system, save production costs, and help improve the competitiveness of the enterprise.

[0075] The technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0076] Example 1

[0077] The polysilicon cold hydrogenation reaction system of the present embodiment includes: a supplementary hydrogen compressor, a silicon powder high-pressure hopper 21, a silicon powder high-pressure hopper filter 22, a hydrogen recovery filter 23, a silicon powder low-pressure hopper filter 24, a silicon powder low-pressure hopper 25, a cold hydrogenation reactor 2, an air cooler 8, a first cooler 9, a second cooler 10, a heat exchanger 11, a third cooler 12, a coarse fractionation tower 4, a reboiler 5, a first preheater 6, a second preheater 7, a detection unit 13, a pressure swing adsorption unit 14, a heating vaporization unit 1, a cold hydrogenation reactor 2, and a washing and cooling unit 3;

[0078] The outlet of the cold hydrogenation reactor 2 is communicated with the inlet of the washing and cooling unit 3, the gas phase outlet of the washing and cooling unit 3 is communicated with the reboiler 5 of the coarse fraction tower 4, the reboiler 5 is communicated with the heat source inlet of the first preheater 6, the liquid phase outlet of the first preheater 6 is communicated with the chlorosilane inlet of the coarse fraction tower 4, and the cold source outlet of the first preheater 6 is communicated with the inlet of the heating vaporization unit 1; the heat source outlet of the first preheater 6 is communicated with the heat source inlet of the second preheater 7, the circulating silicon tetrachloride outlet of the coarse fraction tower 4 is communicated with the cold source inlet of the second preheater 7, the liquid phase outlet of the second preheater 7 is communicated with the chlorosilane inlet of the coarse fraction tower 4, and the cold source outlet of the second preheater 7 is communicated with the inlet of the heating vaporization unit 1; the heat source outlet of the second preheater 7 is communicated with the inlet of the air cooler 8, the outlet of the air cooler 8 is communicated with the inlet of the first cooler 9, and the liquid phase outlet of the first cooler 9 is communicated with the inlet of the coarse fraction tower 4. The chlorosilane inlet of tower 4 is connected; the gas phase outlet of the first cooler 9 is connected to the inlet of the second cooler 10, and the liquid phase outlet of the second cooler 10 is connected to the chlorosilane inlet of the coarse fractionation tower 4; the gas phase outlet of the second cooler 10 is connected to the heat source inlet of the heat exchanger 11, the heat source outlet of the heat exchanger 11 is connected to the inlet of the third cooler 12, the liquid phase outlet of the third cooler 12 is connected to the chlorosilane inlet of the coarse fractionation tower 4, the gas phase outlet of the third cooler 12 is connected to the cold source inlet of the heat exchanger 11, the cold source outlet of the heat exchanger 11 is connected to the inlet of the detection unit 13, the outlet of the detection unit 13 is respectively connected to the inlet of the pressure swing adsorption unit 14 and the cold source inlet of the first preheater 6; the outlet of the pressure swing adsorption unit 14 is connected to the cold source inlet of the first preheater 6, and the outlet of the heating vaporization unit 1 is connected to the inlet of the cold hydrogenation reactor 2.

[0079] The silicon powder-containing hydrogen outlet of the silicon powder low-pressure hopper 25 is connected to the hydrogen inlet of the silicon powder low-pressure hopper filter 24, the outlet of the silicon powder low-pressure hopper filter 24 is connected to the silicon powder inlet of the silicon powder low-pressure hopper 25, and the silicon powder outlet of the silicon powder low-pressure hopper 25 is connected to the silicon powder inlet of the silicon powder high-pressure hopper 21;

[0080] The outlet of the supplementary hydrogen compressor is connected to the pressurized hydrogen inlet of the silicon powder high-pressure hopper 21, the silicon powder outlet of the silicon powder high-pressure hopper 21 is connected to the silicon powder inlet of the cold hydrogenation reactor 2, the hydrogen outlet of the silicon powder high-pressure hopper 21 is connected to the hydrogen inlet of the silicon powder high-pressure hopper filter 22, the silicon powder-containing hydrogen outlet of the silicon powder high-pressure hopper filter 22 is connected to the hydrogen inlet of the recovery hydrogen filter 23, and the recovery hydrogen filter 23 has a recovery hydrogen outlet;

[0081] The silicon powder high pressure hopper filter 22 is located at the top of the silicon powder high pressure hopper 21, the silicon powder low pressure hopper filter 24 is located at the top of the silicon powder low pressure hopper 25, and the silicon powder low pressure hopper 25 is located at the top of the silicon powder high pressure hopper 21;

[0082] The cooling medium in the first cooler is circulating water, the cooling medium in the second cooler is ethylene glycol, and the cooling medium in the third cooler is -45°C Freon.

[0083] Example 2

[0084] The polysilicon cold hydrogenation reaction method of this embodiment is carried out through the reaction system of embodiment 1, comprising:

[0085] After the silicon powder-containing vent air of the silicon powder low-pressure hopper 25 is filtered by the silicon powder low-pressure hopper filter 24, the recovered silicon powder is output through the outlet of the silicon powder low-pressure hopper filter 24, and enters the silicon powder low-pressure hopper 25 through the silicon powder inlet of the silicon powder low-pressure hopper 25 for storage; the silicon powder stored in the silicon powder low-pressure hopper 25 is output through the silicon powder outlet of the silicon powder low-pressure hopper 25, and enters the silicon powder high-pressure hopper 21 through the silicon powder inlet of the silicon powder high-pressure hopper 21; the silicon powder in the silicon powder high-pressure hopper 21 is transported to the cold hydrogenation reactor 2 by the pressure of the pressurized hydrogen gas, and in the cold hydrogenation reactor 2, the silicon powder, hydrogen and silicon tetrachloride undergo cold hydrogenation reaction to obtain trichlorosilane, The tail gas of the cold hydrogenation reaction of polysilicon containing silicon tetrachloride and hydrogen, the hydrogen containing silicon powder in the silicon powder high-pressure hopper 21 is output through the hydrogen outlet of the silicon powder high-pressure hopper 21, and enters the silicon powder high-pressure hopper filter 22 through the hydrogen inlet of the silicon powder high-pressure hopper filter 22 for the first filtering treatment to obtain intermediate hydrogen; then the intermediate hydrogen is output through the silicon powder hydrogen outlet of the silicon powder high-pressure hopper filter 22, and enters the hydrogen recovery filter 23 through the inlet of the hydrogen recovery filter 23, the intermediate hydrogen is subjected to the second filtering treatment in the hydrogen recovery filter 23 to obtain recovered hydrogen, and the recovered hydrogen obtained is output through the hydrogen recovery outlet of the hydrogen recovery filter 23;

[0086] The reaction tail gas outputted from the outlet of the cold hydrogenation reactor 2 enters the washing and cooling unit 3 for washing and cooling treatment, then enters the reboiler 5 of the coarse fractionation tower 4 to provide heat for the coarse fractionation treatment, and then enters the first preheater 6 through the heat source inlet of the first preheater 6 for the first preheating treatment, and the obtained preheated circulating hydrogen enters the heating vaporization unit 1 through the inlet of the heating vaporization unit 1, and the obtained first intermediate reaction tail gas enters the second preheater 7 through the heat source inlet of the second preheater 7, and the obtained chlorosilane solution enters the coarse fractionation tower 4 through the chlorosilane inlet of the coarse fractionation tower 4 for coarse fractionation treatment; the circulating silicon tetrachloride obtained after the coarse fractionation treatment is discharged from the coarse fractionation tower 4 through the circulating silicon tetrachloride outlet The first intermediate reaction tail gas is output from the outlet of the second preheater 7, enters the second preheater 7 through the cold source inlet of the second preheater 7, in the second preheater 7, the first intermediate reaction tail gas performs a second preheating treatment on the circulating silicon tetrachloride, and the preheated silicon tetrachloride is output from the outlet of the second preheater 7, enters the heating vaporization unit 1 through the inlet of the heating vaporization unit 1, in the heating vaporization unit 1, the preheated silicon tetrachloride is heated and vaporized with the circulating hydrogen, and then output from the outlet of the heating vaporization unit 1, enters the cold hydrogenation reactor 2 through the inlet of the cold hydrogenation reactor 2 to participate in the cold hydrogenation reaction, and the obtained chlorosilane solution is output from the liquid phase outlet of the second preheater 7, and enters the coarse fractionation tower 4 through the chlorosilane inlet of the coarse fractionation tower 4;

[0087] The first intermediate reaction tail gas obtained in the second preheating treatment is output through the heat source outlet of the second preheater 7, enters the air cooler 8 through the inlet of the air cooler 8 for air cooling treatment, the reaction tail gas after the air cooling treatment is output through the outlet of the air cooler 8, enters the first cooler 9 through the inlet of the first cooler 9 for the first cooling treatment, the obtained chlorosilane solution is output through the liquid phase outlet of the first cooler 9, enters the coarse fractionation tower 4 through the inlet of the coarse fractionation tower 4, the obtained reaction tail gas is output through the gas phase outlet of the first cooler 9, enters the second cooler 10 through the inlet of the second cooler 10 for the second cooling treatment, the obtained chlorosilane solution is output through the liquid phase outlet of the second cooler 10, enters the coarse fractionation tower 4 through the inlet of the coarse fractionation tower 4, the obtained reaction tail gas is output through the gas phase outlet of the second cooler 10, and is successively passed through the exchange The heat source inlet of the heat exchanger 11 enters the heat exchanger 11 for heat exchange treatment and enters the third cooler 12 through the inlet of the third cooler 12 for third cooling treatment, wherein the reaction tail gas output through the heat source outlet of the heat exchanger 11 enters the third cooler 12 through the inlet of the third cooler 12 for third cooling treatment, the obtained chlorosilane solution is output from the liquid phase outlet of the third cooler 12, enters the coarse fractionation tower 4 through the inlet of the coarse fractionation tower 4, the obtained circulating hydrogen is output from the gas phase outlet of the third cooler 12 and enters the heat exchanger 11 through the cold source medium inlet of the heat exchanger 11 for heat exchange treatment, the obtained chlorosilane solution is output from the liquid phase outlet of the heat exchanger 11, enters the coarse fractionation tower 4 through the inlet of the coarse fractionation tower 4, and the obtained first intermediate circulating hydrogen is output from the cold source outlet of the heat exchanger 11;

[0088] The first intermediate cycle hydrogen obtained in the heat exchange process is output from the cold source outlet of the heat exchanger 11 and enters the detection unit 13 through the inlet of the detection unit 13 for nitrogen content detection processing;

[0089] After the nitrogen content detection process is performed, if the nitrogen content in the first intermediate circulating hydrogen is ≥3%, the first intermediate circulating hydrogen is output from the outlet of the detection unit 13 and enters the pressure swing adsorption unit 14 through the inlet of the pressure swing adsorption unit 14 for pressure swing adsorption process, and the obtained pure hydrogen is output from the outlet of the pressure swing adsorption unit 14 and enters the first preheater 6 through the cold source inlet of the first preheater 6 for first preheating process;

[0090] If the nitrogen content in the first intermediate circulating hydrogen is less than 3%, the first intermediate circulating hydrogen is output from the outlet of the detection unit 13 and directly enters the first preheater 6 through the cold source inlet of the first preheater 6 for the first preheating treatment;

[0091] When the pressure of the recovered hydrogen outlet is greater than 0.6MPaG, the recovered hydrogen outlet is connected to the inlet of the hydrogen supplement compressor air inlet buffer tank; when the pressure of the recovered hydrogen outlet is less than or equal to 0.6MPaG, the recovered hydrogen outlet is connected to the hydrogen-containing tail gas recovery system;

[0092] Among them, in the cold hydrogenation reactor 2, the temperature is 550°C and the pressure is 3.0MPa; the pressure in the silicon powder high-pressure hopper is 3.4MPaG;

[0093] After washing and cooling treatment, the temperature of the reaction tail gas is 150°C. After providing heat for coarse separation, the temperature of the reaction tail gas is 120°C. The temperature of the first intermediate reaction tail gas is 115°C. After the second preheating treatment, the temperature of the first intermediate reaction tail gas is 105°C. After air cooling treatment, the temperature of the reaction tail gas is 60°C. After the first cooling treatment, the temperature of the reaction tail gas is 40°C. After the second cooling treatment, the temperature of the reaction tail gas is -15°C. After the third cooling treatment, the temperature of the reaction tail gas is -40°C. The temperature of the first intermediate circulating hydrogen is 10°C.

[0094] When the annual processing capacity is 350,000 tons of silicon tetrachloride (STC), in the polysilicon cold hydrogenation reaction method of this embodiment: after the reaction tail gas is used in the roughing tower reboiler, the refrigerant heat load can be saved by about 5300Kw, which is equivalent to about 455t / h of circulating water (10°C temperature difference); the reaction tail gas can also save hydrogen and silicon tetrachloride heating medium through the first preheater and the second preheater. When 10 kg of steam is used as the heating medium, 3-4t / h can be saved; the reaction tail gas can save about 870Kw of -45°C refrigerant cooling capacity and recover 600-1500Nm of hydrogen through heat exchange treatment. 3 / h.

[0095] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. The above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the scope of protection of the present invention.

Claims

1. A polysilicon cold hydrogenation reaction system, characterized in that: It includes a cold hydrogenation reactor, a hydrogen supplement compressor, a silicon powder high-pressure hopper, a silicon powder high-pressure hopper filter, a hydrogen recovery filter, an air cooler, a first cooler, a second cooler, a heat exchanger and a third cooler; The outlet of the supplementary hydrogen compressor is connected to the pressurized hydrogen inlet of the silicon powder high-pressure hopper, the silicon powder outlet of the silicon powder high-pressure hopper is connected to the silicon powder inlet of the cold hydrogenation reactor, the hydrogen outlet of the silicon powder high-pressure hopper is connected to the hydrogen inlet of the silicon powder high-pressure hopper filter, the silicon powder-containing hydrogen outlet of the silicon powder high-pressure hopper filter is connected to the hydrogen inlet of the hydrogen recovery filter, and the hydrogen recovery filter has a hydrogen recovery outlet; The outlet of the cold hydrogenation reactor is communicated with the inlet of the air cooler, the outlet of the air cooler is communicated with the inlet of the first cooler, the gas phase outlet of the first cooler is communicated with the inlet of the second cooler, the gas phase outlet of the second cooler is communicated with the heat source inlet of the heat exchanger, the heat source outlet of the heat exchanger is communicated with the inlet of the third cooler, and the gas phase outlet of the third cooler is communicated with the cold source medium inlet of the heat exchanger; The cooling medium in the first cooler is circulating water, the cooling medium in the second cooler is at least one of chilled water, ethylene glycol, and -25°C Freon, and the cooling medium in the third cooler is -45°C Freon.

2. The polysilicon cold hydrogenation reaction system according to claim 1, characterized in that: If the pressure of the recovered hydrogen outlet is greater than the inlet pressure of the hydrogen replenishment compressor, the recovered hydrogen outlet is connected to the inlet of the hydrogen replenishment compressor; or, If the pressure of the recovered hydrogen outlet is less than or equal to the inlet pressure of the supplementary hydrogen compressor, the recovered hydrogen outlet is connected to the hydrogen-containing tail gas recovery system.

3. The polysilicon cold hydrogenation reaction system according to claim 1 or 2, characterized in that: The silicon powder high-pressure hopper filter is located at the top of the silicon powder high-pressure hopper, and the gas outlet of the silicon powder high-pressure hopper is communicated with the gas inlet of the silicon powder high-pressure hopper filter.

4. The polysilicon cold hydrogenation reaction system according to any one of claims 1 to 3, characterized in that: It also includes a silicon powder low-pressure hopper, the outlet of which is connected to the silicon powder inlet of the silicon powder high-pressure hopper.

5. The polysilicon cold hydrogenation reaction system according to claim 4, characterized in that: It also includes a silicon powder low-pressure hopper filter, the gas outlet of the silicon powder low-pressure hopper is connected to the gas inlet of the silicon powder low-pressure hopper filter, and the silicon powder outlet of the silicon powder low-pressure hopper is connected to the silicon powder inlet of the silicon powder high-pressure hopper.

6. The polysilicon cold hydrogenation reaction system according to claim 5, characterized in that: The silicon powder low-pressure hopper filter is located at the top of the silicon powder low-pressure hopper; and / or, The silicon powder low-pressure hopper is located on the top of the silicon powder high-pressure hopper.

7. The polysilicon cold hydrogenation reaction system according to any one of claims 1 to 6, characterized in that: It also includes a coarse fractionation tower, wherein the liquid phase outlet of the first cooler, the liquid phase outlet of the second cooler, the liquid phase outlet of the third cooler and the liquid phase outlet of the heat exchanger are respectively connected to the inlet of the coarse fractionation tower.

8. The polysilicon cold hydrogenation reaction system according to claim 7, characterized in that: The coarse fraction tower comprises a reboiler, and the reaction tail gas is connected to the reboiler; and / or, Also includes a first preheater and a second preheater; The reaction tail gas is connected to the heat source inlet of the first preheater, the cold source outlet of the heat exchanger is connected to the cold source inlet of the first preheater, the heat source outlet of the first preheater is connected to the heat source inlet of the second preheater, the silicon tetrachloride outlet of the coarse fractionation tower is connected to the cold source inlet of the second preheater, and the heat source outlet of the second preheater is connected to the inlet of the air cooler.

9. The polysilicon cold hydrogenation reaction system according to claim 8, characterized in that: It also includes a heating vaporization unit, wherein the cold source outlet of the first preheater is connected to the inlet of the heating vaporization unit, the cold source outlet of the second preheater is connected to the inlet of the heating vaporization unit, and the outlet of the heating vaporization unit is connected to the cold hydrogenation reactor.

10. A method for cold hydrogenation of polysilicon, characterized in that: The method is carried out using the polysilicon cold hydrogenation reaction system described in any one of claims 1 to 9.

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