A silane gas production system and method based on a double reaction rectification column

Abstract

The application provides a silane gas production system and method based on double reaction distillation columns. The system comprises a second reaction distillation column (2) arranged in the silane gas production system, a middle input end of the second reaction distillation column (2) is connected with a bottom output end of a silane distillation column (3) in the silane gas production system, receives an intermediate mixture output from the silane distillation column (3) and performs a disproportionation reaction; a top output end of the second reaction distillation column (2) is connected with a top output end of a first reaction distillation column (1) in the silane gas production system, and the mixture in the second reaction distillation column (2) is subjected to subsequent treatment; and a bottom output end of the second reaction distillation column (2) is connected with a middle input end of the first reaction distillation column (1) in the silane gas production system, and the output from the first reaction distillation column (1) is subjected to a disproportionation reaction. The method is realized by using the system to produce silane gas based on double reaction distillation columns.

Description

TECHNICAL FIELD

[0001] The present application relates to a silane gas production system and method, in particular to a silane gas production system and method based on double reaction rectification columns. BACKGROUND

[0002] The information provided in this section is merely background information related to the present disclosure and can not necessarily be prior art.

[0003] The silane gas production process is divided into fixed bed reaction process and reaction rectification process. Both processes use chlorosilane as raw material. Due to the factors of production conversion rate and reaction component change, not all chlorosilane in the system will participate in the reaction, and not all produced silane gas will be purified as product. Maximizing silane gas yield is the direction of silane gas production research.

[0004] In the existing production process, the fixed bed reaction process has high production cost. The reaction rectification production process is affected by the material components. The produced silane gas is dissolved in chlorosilane material, which needs to be gradually purified and separated to obtain silane gas product. The light component chlorosilane after separation returns to the reaction rectification column for reaction, which increases the separation load of the reaction rectification column and increases the energy consumption.

[0005] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present disclosure, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0006] The purpose of the present application is to solve the technical problems of the prior art and provide a silane gas production system and method based on double reaction rectification columns.

[0007] In order to solve the above technical problems, the present application discloses a silane gas production system and method based on double reaction rectification columns, which comprises:

[0008] A second reaction rectification column is arranged in the silane gas production system. The middle input end of the second reaction rectification column is connected with the bottom output end of the silane rectification column in the silane gas production system, receives the output intermediate mixture and performs disproportionation reaction.

[0009] The top output end of the second reaction rectification column is connected with the top output end of the first reaction rectification column in the silane gas production system, and the mixture is subjected to subsequent treatment.

[0010] The bottom output end of the second reaction rectification column is connected with the middle input end of the first reaction rectification column in the silane gas production system, and the output substance is subjected to disproportionation reaction.

[0011] The silane gas production system comprises:

[0012] The first reaction rectifying tower is provided with a middle input end for receiving trichlorosilane TCS transmitted by an upstream system and performing a disproportionation reaction; and a bottom output end for outputting liquid-phase silicon tetrachloride STC generated by the reaction;

[0013] The top output end of the first reaction rectifying tower is connected with an input end of a cooling heat exchange system, and the crude silane generated by the reaction is subjected to cooling heat exchange to obtain liquid-phase crude silane;

[0014] The bottom of the first reaction rectifying tower is further provided with a first reaction rectifying tower reboiler for providing heat for the first reaction rectifying tower;

[0015] The output end of the cooling heat exchange system is connected with an input end of a silane rectifying tower, the silane rectifying tower is used for rectifying the liquid-phase crude silane input thereto, the top of the silane rectifying tower is provided with a silane rectifying tower condenser, a gas-phase part of the top of the silane rectifying tower is condensed into a liquid phase by the silane rectifying tower condenser and serves as reflux of the silane rectifying tower, and a non-condensed part serves as a gas-phase impurity and is discharged, a side line output end of the silane rectifying tower outputs silane, a bottom output end of the silane rectifying tower outputs the intermediate mixture, and the bottom of the silane rectifying tower is provided with a silane rectifying tower reboiler for providing heat for the silane rectifying tower.

[0016] The cooling heat exchange system comprises:

[0017] The first-stage condenser, the second-stage condenser, the third-stage condenser, the fourth-stage heat exchanger and the fifth-stage condenser are connected in sequence;

[0018] The condensate pipeline of the first-stage condenser is connected with a reflux tank, the reflux tank is used for storing condensate of the first-stage condenser, the reflux tank is connected with the top input end of the first reaction rectifying tower through a reflux pump, and the reflux pump is used for pressurizing the condensate;

[0019] The condensate pipelines of the second-stage condenser and the third-stage condenser are connected with the middle input end of the first reaction rectifying tower, and the condensate is used for continuing the disproportionation reaction;

[0020] The fourth-stage heat exchanger performs heat exchange by taking the liquid-phase crude silane condensed from the fifth-stage condenser as a cold source.

[0021] The cooling heat exchange system further comprises:

[0022] A silane phase separation tank connected with the output end of the fifth-stage condenser and used for storing the liquid-phase crude silane, and an output end of the silane phase separation tank is connected with a silane pressurizing pump, which is used for pressurizing the liquid-phase crude silane and inputting the liquid-phase crude silane to a downstream device.

[0023] The intermediate mixture is a mixture of trichlorosilane TCS, dichlorodisilane DCS and chlorotriisilane MCS.

[0024] The first reaction rectifying column comprises:

[0025] The first catalyst packing section is used for trichlorosilane TCS disproportionation reaction, the first rectifying section is used for preliminary purification of silane, and the first stripping section is used for purification of silicon tetrachloride STC.

[0026] Liquid phase silicon tetrachloride STC is obtained in the tower kettle of the first reaction rectifying column, and a gas phase silane mixture containing trichlorosilane TCS, dichlorodisilane DCS, chlorotriisilane MCS and silane, i.e. crude silane, is obtained at the top of the column.

[0027] The pressure in the first reaction rectifying column is set to 0.1 Mpa (G) -0.4 Mpa (G), and the temperature of the first catalyst packing section is set to 20-150℃.

[0028] The second reaction rectifying column comprises:

[0029] The second catalyst packing section is used for trichlorosilane TCS disproportionation reaction, the second stripping section is used for purification of trichlorosilane TCS, and the second rectifying section is used for preliminary purification of silane.

[0030] A mixture containing trichlorosilane TCS and dichlorodisilane DCS is obtained in the tower kettle of the second reaction rectifying column, and a second reaction rectifying column condenser is provided at the top of the column, and a gas phase silane mixture containing dichlorodisilane DCS, chlorotriisilane MCS and silane, i.e. crude silane, is obtained by condensation.

[0031] The crude silane is condensed again into liquid phase chlorosilane material by the second reaction rectifying column condenser, and returned to the second reaction rectifying column as reflux at the top of the column.

[0032] The second reaction rectifying column further comprises a second reaction rectifying column reboiler for providing heat to the second reaction rectifying column.

[0033] The pressure in the second reaction rectifying column is set to 1.5 Mpa (G) -0.6 Mpa (G), and the temperature of the second catalyst packing section is set to 20-150℃.

[0034] The inlet temperature of the primary condenser is set to 30-100℃, and the outlet temperature is set to 20-60℃.

[0035] The inlet temperature of the secondary condenser is set to 20-60 DEG C, and the outlet temperature is set to -20-0 DEG C.

[0036] The inlet temperature of the tertiary condenser is set to -20-0 DEG C, and the outlet temperature is set to -30--60 DEG C.

[0037] The inlet temperature of the heat flow medium in the fourth heat exchanger is set to -30--60 DEG C, and the outlet temperature is set to -40--70 DEG C.

[0038] The inlet temperature of the fifth condenser is set to -40--70 DEG C, and the outlet temperature is set to -70--120 DEG C.

[0039] The reflux pump is a magnetic pump or a shield pump, which is used to increase the pressure to 0.3-2.0 MPa (G).

[0040] The silane booster pump is a magnetic pump or a shield pump, which is used to increase the pressure to 0.6-5.0 MPa (G).

[0041] The column pressure of the silane rectification column is set to 0.5-4.0 MPa (G), the overhead temperature is set to -20--80 DEG C, and the bottom temperature is set to 20-80 DEG C.

[0042] The application also provides a silane gas production method based on a double reaction rectification column, which is realized by using the system.

[0043] Step 1, a second reaction rectification column is arranged in the silane gas production system.

[0044] Step 2, the middle input end of the first reaction rectification column in the silane gas production system receives trichlorosilane TCS transmitted by an upstream system, and performs a disproportionation reaction, and outputs liquid phase silicon tetrachloride STC generated by the reaction through the bottom output end;

[0045] Step 3, the top output end of the second reaction rectification column is connected with the top output end of the first reaction rectification column, the gas output by the two is mixed and then transmitted to the cooling heat exchange system in the silane gas production system, and after cooling heat exchange, liquid phase crude silane is obtained; the bottom output end of the second reaction rectification column is connected with the middle input end of the first reaction rectification column, and the substance output by the bottom output end of the second reaction rectification column is subjected to a disproportionation reaction.

[0046] Step 4, the liquid phase crude silane obtained by the cooling heat exchange system is transmitted to the silane rectification column for rectification, the top output end of the silane rectification column discharges gaseous phase impurities after rectification, the side line output end outputs silane, and the bottom output end transmits the intermediate mixture to the middle part of the second reaction rectification column for a disproportionation reaction.

[0047] Advantages:

[0048] The present application is in the existing method for producing silane gas based on reactive distillation, by increasing a reaction tower, the trichlorosilane and dichlorosilane separated from the top of the original reactive distillation tower are reacted in the new reaction tower, so that the part of the material can produce silane gas under high conversion rate, improve the silane gas production, at the same time avoid the part of the material returning to the original reactive distillation tower, reduce the separation load of the original reactive distillation tower. BRIEF DESCRIPTION OF DRAWINGS

[0049] The above and / or other aspects of the present application will become apparent and more readily appreciated from the following description, taken in conjunction with the accompanying drawings, in which:

[0050] Figure 1 It is a schematic diagram of the overall architecture of the present application.

[0051] Wherein:

[0052] 1 is a reactive distillation 1# tower; 2 is a reactive distillation 2# tower; 3 is a silane distillation tower; 4 is a reflux tank; 5 is a silane phase separation tank; 6 is a reflux pump; 7 is a silane booster pump; 8 is a first-stage condenser; 9 is a second-stage condenser; 10 is a third-stage condenser; 11 is a fourth-stage heat exchanger; 12 is a fifth-stage condenser; 13 is a silane distillation tower condenser; 14 is a reactive distillation 2# tower condenser; 15 is a reactive distillation 1# tower reboiler; 16 is a silane distillation tower reboiler; 17 is a reactive distillation 2# tower reboiler. DETAILED DESCRIPTION

[0053] The general idea of the present application is as follows:

[0054] According to the existing reactive distillation production process and the characteristics of the reaction conversion rate of trichlorosilane, dichlorosilane and trichlorosilane being weakened in turn, the light chlorosilane (trichlorosilane, dichlorosilane) purified in the reactive distillation system is introduced into a reactive distillation tower for reaction, so as to improve the silane gas production of the reactive distillation production process and further reduce the production energy consumption.

[0055] According to the above design idea, the present application provides a system and method for producing high-purity silane by trichlorosilane reactive distillation, which adopts a multi-stage condensation and distillation tower combined treatment process, and the process flow chart is as follows: Figure 1As shown in the figure, wherein 1 is reaction rectification 1# tower; 2 is reaction rectification 2# tower; 3 is silane rectification tower; 4 is reflux tank; 5 is silane phase separation tank; 6 is reflux pump; 7 is silane booster pump; 8 is first stage condenser; 9 is second stage condenser; 10 is third stage condenser; 11 is fourth stage heat exchanger; 12 is fifth stage condenser; 13 is silane rectification tower condenser; 14 is reaction rectification 2# tower condenser; 15 is reaction rectification 1# tower reboiler; 16 is silane rectification tower reboiler; 17 is reaction rectification 2# tower reboiler.

[0056] As shown in the figure, wherein 1 is reaction rectification 1# tower; 2 is reaction rectification 2# tower; 3 is silane rectification tower; 4 is reflux tank; 5 is silane phase separation tank; 6 is reflux pump; 7 is silane booster pump; 8 is first stage condenser; 9 is second stage condenser; 10 is third stage condenser; 11 is fourth stage heat exchanger; 12 is fifth stage condenser; 13 is silane rectification tower condenser; 14 is reaction rectification 2# tower condenser; 15 is reaction rectification 1# tower reboiler; 16 is silane rectification tower reboiler; 17 is reaction rectification 2# tower reboiler. Figure 1 The technical scheme provided by the present application specifically comprises the following steps:

[0057] Step 1, trichlorosilane (TCS) enters reaction rectification 1# tower 1, and after disproportionation reaction and rectification purification, crude silane is obtained at the top of the tower, and high-purity liquid-phase silicon tetrachloride STC is obtained at the bottom.

[0058] Step 2, the crude silane obtained at the top of reaction rectification 1# tower 1 passes through first stage condenser 8, second stage condenser 9 and third stage condenser 10 in sequence, wherein the condensate of first stage condenser 8 enters reflux tank 4, is pressurized by reflux pump 6, and then enters the top of reaction rectification 1# tower 1 as backflow, the condensate of second stage condenser 9 and third stage condenser 10 flows back to the middle part of reaction rectification 1# tower 1 to continue disproportionation reaction, and the condensed gas is gaseous crude silane.

[0059] Step 3, the gaseous crude silane condensed in step 2 enters fourth stage heat exchanger 11, and the liquid-phase crude silane condensed by fifth stage condenser 12 is used as a cold source for heat exchange of fourth stage heat exchanger 11, and the crude silane after heat exchange of fourth stage heat exchanger 11 enters fifth stage condenser 12 to be condensed, and liquid-phase crude silane is obtained.

[0060] Step 4, the liquid-phase crude silane obtained by passing through fifth stage condenser 12 in step 3 enters silane phase separation tank 5, is pressurized by silane booster pump 7, and enters silane rectification tower 3 for rectification, the gaseous phase part at the top of the tower is condensed into liquid-phase silane rectification tower 3 backflow by silane rectification tower condenser 13, a small amount of uncondensed part is discharged from the top of the tower as gaseous impurities, and a part of trichlorosilane TCS, dichlorodisilane DCS and monochlorotrisilane MCS mixture is obtained at the bottom of the tower, the remaining part of the material in the kettle is heated by silane rectification tower reboiler 16 and then returned to silane rectification tower 3 to provide heat for the tower, and high-purity silane with silane content ≥ 99.9999% is obtained from the side line of silane rectification tower 3.

[0061] Step 5, the mixture of TCS, DCS and MCS from the bottom of the silane rectification column 3 in step 4 is introduced into the middle of the reaction rectification 2# column 2 for dismutation reaction again, the gaseous crude silane condensed by the reaction rectification 2# column condenser 14 is mixed with the overhead product of the reaction rectification 1# column 1, and then condensed and purified to obtain silane gas, and the liquid chlorosilane condensed by the reaction rectification 2# column condenser 14 is returned to the reaction rectification 2# column 2 as the reflux, the mixture of TCS and DCS from the bottom of the reaction rectification 2# column 2 is introduced into the middle of the reaction rectification 1# column 1 for dismutation reaction again, and the remaining material in the column is heated by the reaction rectification 2# column reboiler 17 and returned to the reaction rectification 2# column 2 to provide heat for the column.

[0062] Step 6, the reaction rectification 1# column 1 is composed of a catalyst packing section, a rectification section and a stripping section, the dismutation reaction of TCS is carried out in the catalyst packing section, the rectification section is used for purifying silane, and the stripping section is used for purifying STC, the high-purity liquid STC is obtained from the bottom of the column, part of the product is taken out of the system, and the remaining part is heated by the reaction rectification 1# column reboiler 15 and returned to the reaction rectification 2# column 1 to provide heat for the column; the rectification section is used for purifying silane, and the gaseous silane mixture containing TCS, DCS, MCS and silane is obtained from the top of the column, that is, crude silane. The pressure in the reaction rectification 1# column 1 is 0.1 MPa (G)-0.4 MPa (G), and the temperature in the catalyst packing section is 20-150 ℃.

[0063] In a specific embodiment, the first-stage condenser 8 preferably uses circulating water as a cold source, the inlet temperature of the first-stage condenser is 30-100 ℃, and the outlet temperature is 20-60 ℃.

[0064] In a specific embodiment, the reflux tank 4 stores the mixture containing TCS, DCS and MCS condensed by the first-stage condenser, and the temperature is 20-60 ℃.

[0065] In a specific embodiment, the reflux pump 6 preferably uses a magnetic pump or a canned motor pump to increase the pressure of the liquid chlorosilane mixture obtained from the reflux tank 4 to 0.3-2.0 MPa (G).

[0066] In a specific embodiment, the second-stage condenser 9 preferably uses an aqueous ethylene glycol solution as a cold source, the inlet temperature of the second-stage condenser is 20-60 ℃, and the outlet temperature is -20-0 ℃.

[0067] In a specific embodiment, the third-stage condenser 10 preferably uses Freon as a cold source, the inlet temperature of the third-stage condenser is -20-0 ℃, and the outlet temperature is -30--60 ℃.

[0068] In a specific embodiment, the fourth heat exchanger 11 exchanges heat with the crude silane condensed by the fifth condenser 12 as a cold source, the fourth heat exchanger has an inlet temperature of -30℃ to -60℃ and an outlet temperature of -40℃ to -70℃, and the crude silane exchanged by the fourth heat exchanger contains trichlorosilane TCS, dichlorodisilane DCS, chlorotrisilane MCS and silane MS.

[0069] In a specific embodiment, the cold source of the fifth condenser 12 is preferably one of ethylene, R23 and liquid nitrogen, the fifth condenser has an inlet temperature of -40℃ to -70℃ and an outlet temperature of -70℃ to -120℃.

[0070] In a specific embodiment, the silane phase separation tank 5 stores the liquid-phase crude silane condensed by the fifth condenser 12, and the temperature is -70℃ to -120℃.

[0071] In a specific embodiment, the silane booster pump 7 is preferably a magnetic pump or a canned pump, which boosts the pressure of the liquid-phase crude silane stored in the silane phase separation tank to 0.6MPa(G) to 5.0MPa(G).

[0072] In a specific embodiment, the column pressure of the silane rectification column 3 is 0.5MPa(G) to 4.0MPa(G), and the overhead temperature is -20℃ to -80℃.

[0073] In a specific embodiment, the temperature of the silane rectification column condenser 13 is -30℃ to -90℃, and the gaseous impurities are discharged from the overhead.

[0074] In a specific embodiment, the bottom temperature of the silane rectification column 3 is 20℃ to 80℃, and the trichlorosilane TCS, dichlorodisilane DCS and chlorotrisilane MCS mixture is obtained from the bottom.

[0075] In a specific embodiment, the reaction rectification 2# column 2 is composed of a catalyst packing section, a rectification section and a stripping section, the TCS disproportionation reaction is carried out in the catalyst packing section, the trichlorosilane TCS is purified in the stripping section, and the trichlorosilane TCS and dichlorodisilane DCS mixture is obtained from the column bottom; the silane is preliminarily purified in the rectification section, and the gaseous silane mixture containing dichlorodisilane DCS, chlorotrisilane MCS and silane, i.e. the crude silane, is obtained from the overhead. The pressure of the reaction rectification 2# column 2 is 1.5MPa(G) to 0.6MPa(G), and the temperature of the catalyst packing section is 20℃ to 150℃.

[0076] In a specific embodiment, the reaction rectification 2# column condenser 14 preferably uses circulating water as a cold source, the inlet temperature of the reaction rectification 2# column condenser 14 is 30℃ to 100℃, and the outlet temperature is 20℃ to 60℃.

[0077] In one specific embodiment, the reaction rectification 1# column reboiler 15 preferably uses steam as a heat source.

[0078] In one specific embodiment, the silane rectification column reboiler 16 preferably uses steam as a heat source.

[0079] In one specific embodiment, the reaction rectification 2# column reboiler 17 preferably uses steam as a heat source.

[0080] The present application improves the silane gas production capacity of the existing silane reaction system (10% increase in the existing silane gas production capacity) by adding a reaction rectification column, while further reducing the energy consumption of the system (steam consumption reduced by 0.82 t / t.SiH4).

[0081] In a specific implementation, the present application provides a computer storage medium and a corresponding data processing unit, wherein the computer storage medium can store a computer program, and the computer program can run the invention content of a silane gas production system and method based on a double reaction rectification column and some or all steps in each embodiment when executed by the data processing unit. The storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM), etc.

[0082] Those skilled in the art can clearly understand that the technical solutions in the embodiments of the present application can be realized by means of a computer program and its corresponding general hardware platform. Based on such understanding, the technical solutions in the embodiments of the present application or the parts that essentially contribute to the prior art can be embodied in the form of a computer program, i.e., a software product, which can be stored in a storage medium, including a plurality of instructions for causing a device (which can be a personal computer, a server, a single-chip microcomputer, an MCU, or a network device, etc.) containing a data processing unit to execute the method described in each embodiment or some parts of the embodiments of the present application.

[0083] The present application provides a silane gas production system and method based on a double reaction rectification column. There are many methods and ways to implement this technical solution, and the above description is only the preferred embodiment of the present application. It should be noted that for ordinary skilled persons in the technical field, without departing from the principles of the present application, some improvements and refinements can be made, which should also be considered within the scope of protection of the present application. The components not explicitly described in the embodiments can be implemented using existing technology.

Claims

1. A silane gas production system based on a dual reactive distillation column, characterized in that, The system includes: The second reactive distillation column (2) is installed in the silane gas production system. The middle input end of the second reactive distillation column (2) is connected to the bottom output end of the silane distillation column (3) in the silane gas production system to receive the intermediate mixture output by it and carry out the disproportionation reaction. The top output of the second reactive distillation column (2) is connected to the top output of the first reactive distillation column (1) in the silane gas production system, and the substances therein are mixed and then processed. The bottom output end of the second reactive distillation column (2) is connected to the middle input end of the first reactive distillation column (1) in the silane gas production system, and the substances output by it undergo a disproportionation reaction. The silane gas production system includes: The middle input end of the first reactive distillation column (1) is used to receive trichlorosilane TCS transmitted from the upstream system and carry out a disproportionation reaction; the bottom output end of the first reactive distillation column (1) outputs the liquid phase silicon tetrachloride STC produced by the reaction. The top output end of the first reactive distillation column (1) is connected to the input end of the cooling heat exchange system, and the crude silane produced by the reaction is cooled and heat exchanged to obtain liquid crude silane; The bottom of the first reactive distillation column (1) is also provided with a first reactive distillation column reboiler (15) to provide heat to it; The output end of the cooling heat exchange system is connected to the input end of the silane distillation column (3). The silane distillation column (3) is used to distill the input liquid crude silane. The top of the silane distillation column (3) is equipped with a silane distillation column condenser (13). The gas phase at the top of the silane distillation column (3) is condensed into a liquid phase by the silane distillation column condenser (13) and used as reflux of the silane distillation column (3). The uncondensed part is discharged as gas phase impurities. The side output end of the silane distillation column (3) outputs silane. The bottom output end of the silane distillation column (3) outputs the intermediate mixture. The bottom of the silane distillation column (3) is equipped with a silane distillation column reboiler (16) to provide heat for it. The cooling heat exchange system includes: The first-stage condenser (8), the second-stage condenser (9), the third-stage condenser (10), the fourth-stage heat exchanger (11), and the fifth-stage condenser (12) are connected in sequence. The condensate pipe of the first-stage condenser (8) is connected to the reflux tank (4), which is used to store the condensate of the first-stage condenser (8). The reflux tank (4) is connected to the top input end of the first reactive distillation column (1) via a reflux pump (6), which is used to pressurize the condensate. The condensate pipes of the secondary condenser (9) and the tertiary condenser (10) are connected to the middle input end of the first reactive distillation column (1), and the condensate is used to continue the disproportionation reaction; The fourth-stage heat exchanger (11) uses the liquid-phase crude silane condensed in the fifth-stage condenser (12) as a cold source for heat exchange; The cooling heat exchange system further includes: A silane phase separation tank (5) connected to the output end of the five-stage condenser (12) is used to store the liquid phase crude silane. The output end of the silane phase separation tank (5) is connected to a silane booster pump (7) to pressurize the liquid phase crude silane and input it to the downstream device. The intermediate mixture is a mixture of trichlorosilane (TCS), dichlorodisilane (DCS), and monochlorotrisilane (MCS).

2. The silane gas production system based on a dual reactive distillation column according to claim 1, characterized in that, The first reactive distillation column (1) includes: The system comprises a first catalyst packing section, a first rectification section, and a first stripping section, wherein the first catalyst packing section is used for the disproportionation reaction of trichlorosilane (TCS), the first stripping section is used for the purification of silicon tetrachloride (STC), and the first rectification section is used for the preliminary purification of silanes. In the bottom of the first reactive distillation column (1), liquid silicon tetrachloride STC is obtained, and a gaseous silane mixture containing trichlorosilane TCS, dichlorodisilazane DCS, monochlorotrisilane MCS and silane is obtained at the top of the column, namely crude silane. The pressure in the first reactive distillation column (1) is set to 0.1 MPa (G) - 0.4 MPa (G), and the temperature of the first catalyst packing section is set to 20°C to 150°C.

3. A silane gas production system based on a dual reactive distillation column according to claim 2, characterized in that, The second reactive distillation column (2) includes: The second catalyst packing section, the second rectification section, and the second stripping section are used for the disproportionation reaction of trichlorosilane (TCS), the second stripping section is used for the purification of trichlorosilane (TCS), and the second rectification section is used for the preliminary purification of silane. The bottom of the second reactive distillation column (2) yields a mixture containing trichlorosilane TCS and dichlorodisilane DCS. The top of the column is equipped with a second reactive distillation column condenser (14) to condense and obtain a gaseous silane mixture containing dichlorodisilane DCS, monochlorotrisilane MCS and silane, namely crude silane. The crude silane is condensed again into liquid chlorosilane material by the condenser (14) of the second reactive distillation column and returned to the second reactive distillation column (2) as top reflux. The second reactive distillation column (2) also includes a second reactive distillation column reboiler (17) for providing heat to the second reactive distillation column (2); The pressure in the second reactive distillation column (2) is set to 1.5 MPa (G) - 0.6 MPa (G), and the temperature of the second catalyst packing section is set to 20°C to 150°C.

4. A silane gas production system based on a dual reactive distillation column according to claim 3, characterized in that, The inlet temperature of the primary condenser (8) is set to 30°C to 100°C, and the outlet temperature is set to 20°C to 60°C. The inlet temperature of the secondary condenser (9) is set to 20°C to 60°C, and the outlet temperature is set to -20°C to 0°C. The inlet temperature of the three-stage condenser (10) is set to -20℃ to 0℃, and the outlet temperature is set to -30℃ to -60℃. The inlet temperature of the heat flow medium in the four-stage heat exchanger (11) is set to -30°C to -60°C, and the outlet temperature is set to -40°C to -70°C. The inlet temperature of the five-stage condenser (12) is set to -40°C to -70°C, and the outlet temperature is set to -70°C to -120°C. The reflux pump (6) is a magnetic pump or a canned pump, used to boost the pressure to 0.3 MPa (G) to 2.0 MPa (G); The silane booster pump (7) is a magnetic pump or a canned pump used to boost pressure to 0.6 MPa (G) to 5.0 MPa (G).

5. A silane gas production system based on a dual reactive distillation column according to claim 4, characterized in that, The pressure of the silane distillation column (3) is set to 0.5MPa(G)-4.0MPa(G), the top temperature is set to -20℃ to -80℃, and the bottom temperature is set to 20℃ to 80℃.

6. A method for producing silane gas based on a dual reactive distillation column, characterized in that, Implemented using any one of claims 1 to 5, comprising: Step 1: Install the second reactive distillation column (2) in the silane gas production system; Step 2: The middle input end of the first reactive distillation column (1) in the silane gas production system receives trichlorosilane TCS transmitted from the upstream system and performs a disproportionation reaction, and outputs the liquid silicon tetrachloride STC produced by the reaction through its bottom output end. Step 3: The top output end of the second reactive distillation column (2) is connected to the top output end of the first reactive distillation column (1), and the gases output from the two are mixed and then transmitted to the cooling heat exchange system in the silane gas production system. After cooling heat exchange, liquid crude silane is obtained; The bottom output end of the second reactive distillation column (2) is connected to the middle input end of the first reactive distillation column (1), and the substance output from the bottom of the second reactive distillation column (2) undergoes a disproportionation reaction. Step 4: The liquid crude silane obtained from the cooling heat exchange system is transferred to the silane distillation column (3) for distillation. The top output end of the silane distillation column (3) discharges the gaseous impurities after distillation, the side output end outputs silane, and the bottom output end transfers the intermediate mixture to the middle part of the second reactive distillation column (2) for disproportionation reaction.

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