DCS reaction rectification device and silane production system

Abstract

The utility model provides a DCS reaction rectification device and a silane production system, and relates to the technical field of silane gas production. The DCS reactive distillation device comprises: a device body; the DCS catalytic reaction section is arranged in the device body; the TCS catalytic reaction section is arranged in the device body and is positioned below the DCS catalytic reaction section; tCS generated by disproportionation reaction in the DCS catalytic reaction section moves downwards in a liquid state to the TCS catalytic reaction section to participate in reaction; dCS generated by the disproportionation reaction of the TCS catalytic reaction section is in a gaseous state and moves upwards to the DCS catalytic reaction section to participate in the reaction. The silane production system comprises the DCS reaction rectification device. According to the utility model, the conversion rate of converting the byproduct TCS into SiH4 in the DCS disproportionation catalytic reaction process can be improved, the yield of silane gas produced by taking DCS as a raw material is improved, the process is simple, the equipment investment is low, and the operation energy consumption is low.

Description

Technical Field

[0001] The utility model relates to the technical field of silane gas production, in particular to a DCS reactive distillation device and a silane production system. Background Technique

[0002] Silane, namely the compound of silicon and hydrogen, is the general name of a series of compounds, including (SiH4), (Si2H6) and some higher silanes, with the general formula SinH2n+2. Flexible chemical reactions can be completed by using silane to produce silicon materials with high purity and high fineness (up to atomic size).

[0003] Methane silane, also known as silane, with the chemical formula SiH4, is the most common silane. Sometimes methane silane is simply referred to as silane. Methane silane can be used to manufacture high-purity polysilicon, monocrystalline silicon, microcrystalline silicon, amorphous silicon, silicon nitride, silicon oxide, hetero-silicon and various metal silicides. Because of its high purity and easy fine control, it has become the most important special gas in semiconductor microelectronics technology and cannot be replaced by other silicon sources. Methane silane is widely used in the microelectronics and optoelectronics industries, for manufacturing solar cells, flat panel displays, glass and other fields, and is the intermediate product for the global large-scale production of granular silicon so far.

[0004] The manufacturing processes of methane silane can be mainly divided into three types: magnesium silicide method, lithium aluminum hydride method and chlorosilane disproportionation method.

[0005] 1) The magnesium silicide method is the first industrial synthesis method of SiH4 developed abroad earlier. It contains relatively low metals. The crude silane adopts purification processes such as rectification or adsorption, complexation, absorption, etc. Its advantages are simple and mature process, wide raw material sources and low cost. Its disadvantages are high energy consumption for separating and recycling liquid ammonia, but the SiH4 yield is relatively low (the average yield is 80%).

[0006] 2) The lithium aluminum hydride method uses the strong reducing agent LiAlH4 in the solvent of dimethyl ether tetrahydrofuran to generate SiH4 gas through the reduction reaction SiCl4 + LiAlH4 → SiH4 + LiCl + AlCl3. The raw materials LiAlH4 and SiCl4 used in this method are easy to generate, but the chemical activity of the raw materials is strong, the reaction is violent, the danger is high, and it is difficult to control in the production process.

[0007] 3) The chlorosilane disproportionation method (i.e., the improved Siemens method) is to prepare chlorosilane by hydrogenation of chlorosilane and industrial silicon powder under the action of a catalyst, and then prepare silane through a secondary disproportionation reaction. It is simply called the "two-step" disproportionation process. The conversion rate of the first step of disproportionation is relatively low, and the conversion rate of the second step of disproportionation is high. The main reactions are:

[0008] SiCl4 + H2 + Si → SiHCl3, (hydrogenation reaction)

[0009] SiHCl3 → SiH2Cl2 + SiCl4, (the first disproportionation reaction)

[0010] SiH2Cl2 → SiH4 + SiHCl3. (the second disproportionation reaction)

[0011] The improved Siemens process is a widely used industrial production process with an annual output scale of up to 100,000 tons. It is also an ideal method for producing several silicon source gases (SiH4, SiH2Cl2, SiHCl3). All three silicon source gases can be widely used in the optoelectronics, microelectronics, and optical fiber manufacturing fields. The production process is mature, can be continuously produced, and the production process can be adjusted according to the usage of various silicon products. Therefore, the cost of manufacturing silane is low. In the SiHCl3 → SiH2Cl2 → SiH4 production chain, purification and separation are included in each step, and the final product has high purity. Therefore, this method has been widely used in large-scale silane production. It is used to prepare various microelectronic thin films and a series of silicon-containing substances such as single-crystalline silicon, polycrystalline silicon, amorphous silicon, metal silicides, silicon nitride, silicon carbide, and silicon oxide.

[0012] In the improved Siemens process, the main raw materials, intermediate products, and products include: monochlorosilane, dichlorosilane, trichlorosilane, silicon tetrachloride, and silane. Among them, monochlorosilane (MCS) is an inorganic silicon compound with the chemical formula SiH3Cl and the English name: monochlorosilane, usually abbreviated as MCS. Currently, monochlorosilane is more used as an intermediate to synthesize compounds such as TSA and is widely used in the semiconductor chip industry and the solar energy industry. Dichlorosilane (DCS) is an inorganic silicon compound with the chemical formula SiH2Cl2 and the English name: dichlorosilane, usually abbreviated as DCS. DCS has a wide range of uses and is one of the commonly used special gases in the current integrated circuit industry and semiconductor chips. Trichlorosilane (TCS) is an inorganic silicon compound with the chemical formula SiHCl3 and the English name: trichlorosilane, usually abbreviated as TCS, mainly used to manufacture compounds. Silicon tetrachloride (STC), also known as tetrachlorosilane, is an inorganic silicon compound with the chemical formula SiCl4 and the English name: tetrachlorosilane, usually abbreviated as STC, mainly used to produce pure silicon, ethyl silicate, etc., and is also used to produce smoke agents.

[0013] Gaseous silane is also known as silane gas. Currently, the main processes for producing silane gas mainly include the disproportionation reaction of DCS based on the improved Siemens method to prepare silane gas. Although the disproportionation conversion rate of DCS is high, the disproportionation reaction of DCS will by-produce TCS. The single-pass conversion rate of TCS is relatively low, and the material components at the reactor outlet are complex. It is necessary to pass through a multi-stage rectification column to completely separate each component. If the by-produced TCS from the disproportionation reaction of DCS is to be fully utilized, it will increase equipment investment and operating energy consumption. If the by-produced TCS is not fully utilized, the yield of silane gas prepared by the disproportionation reaction of DCS will be limited. Utility Model Content

[0014] In order to solve the problem in the prior art that it is difficult to fully utilize the TCS by-produced from the disproportionation reaction of DCS, resulting in the limitation of the yield of silane gas prepared by the disproportionation reaction of DCS, the present utility model provides a DCS reactive distillation device and a silane production system that can improve the conversion rate of TCS, strengthen the utilization of TCS, and thus increase the yield of silane gas.

[0015] The technical solution adopted by the present utility model is as follows:

[0016] A DCS reactive distillation device uses DCS as a raw material to produce SiH4 and STC. The DCS reactive distillation device includes:

[0017] The device body;

[0018] The DCS catalytic reaction section is arranged in the device body; and

[0019] The TCS catalytic reaction section is arranged in the device body and is located below the DCS catalytic reaction section;

[0020] Among them, the TCS generated by the disproportionation reaction in the DCS catalytic reaction section moves downward in a liquid state to participate in the reaction in the TCS catalytic reaction section; the DCS generated by the disproportionation reaction in the TCS catalytic reaction section moves upward in a gaseous state to participate in the reaction in the DCS catalytic reaction section.

[0021] Furthermore, the device body at least has:

[0022] The rectifying section is arranged in the device body and is located above the DCS catalytic reaction section, and is used for rectifying and separating the upward moving gas mixture in the device body; and

[0023] The stripping section is arranged in the device body and is located below the TCS catalytic reaction section, and is used for rectifying and separating the downward moving liquid mixture in the device body.

[0024] Furthermore, both the DCS catalytic reaction section and the TCS catalytic reaction section include:

[0025] A pressure plate is arranged at the top of the DCS catalytic reaction section or the TCS catalytic reaction section, allowing the passage of gas phase and liquid phase;

[0026] A support plate is arranged at the bottom of the DCS catalytic reaction section or the TCS catalytic reaction section, allowing the passage of gas phase and liquid phase; and

[0027] Catalyst packing is filled between the pressure plate and the support plate for catalyzing the disproportionation reaction of gas phase and liquid phase.

[0028] Furthermore, the device body at least has:

[0029] A main condenser is arranged at the top of the device body; and

[0030] A main reboiler is arranged below the bottom of the device body.

[0031] Furthermore, the device body at least also has:

[0032] A main feed end is arranged on the side of the device body tower and above the DCS catalytic reaction section for introducing liquid-phase DCS;

[0033] A first main discharge end is connected to the liquid-phase pipeline of the main condenser for extracting the liquid-phase crude SiH4 after rectification and condensation;

[0034] A second main discharge end is connected to the gas-phase pipeline at the top of the device body for extracting the gas-phase crude SiH4 after rectification; and

[0035] A third main discharge end is connected to the liquid-phase connecting pipe between the bottom of the device body and the main reboiler for extracting liquid-phase STC.

[0036] A silane production system for producing SiH4 and STC using DCS as a raw material includes:

[0037] The DCS reactive distillation device as described above.

[0038] Furthermore, it also includes a degassing tower which is connected to the main feed end for rectifying and removing light components and impurities in the introduced DCS raw material.

[0039] Furthermore, it also includes:

[0040] An adsorption device is connected to the second main discharge end for adsorbing and removing solid particle impurities in the gas-phase crude SiH4; and

[0041] A purification tower is connected to the first main discharge end or the adsorption device for rectifying and removing heavy components and impurities including MCS in the crude SiH4;

[0042] Further, the purification column at least has:

[0043] A first SiH4 discharge end, which is connected to the liquid phase pipeline of the purification column condenser at the top of the purification column, and is used for extracting liquid-phase SiH4;

[0044] A second SiH4 discharge end, which is connected to the side of the purification column, and is used for extracting gaseous SiH4; and

[0045] An MCS discharge end, which is connected to the liquid-phase connection pipe between the bottom of the purification column and the reboiler below the bottom of the purification column, and is used for extracting heavy components and impurities containing MCS in the liquid phase.

[0046] Further, it also includes an MCS buffer tank. The MCS buffer tank is connected to the MCS discharge end and the main body feed end of the device body. The MCS buffer tank is used for collecting liquid-phase MCS and can introduce inert gas to transport the liquid-phase MCS into the device body.

[0047] The beneficial effects of the present utility model are:

[0048] 1. The DCS reactive distillation device of the present utility model forms a cyclic flow reaction of reactants between the DCS catalytic reaction section above and the TCS catalytic reaction section below in the device body, in cooperation with the control of temperature and pressure. Macroscopically, the disproportionation reaction equation of DCS is changed from 3SiH2Cl2 → SiH4 + 2SiHCl3 to 2SiH2Cl2 → SiH4 + SiCl4. This not only improves the production rate of silane gas but also reduces equipment investment and operation energy consumption, and solves the problem in the prior art that it is difficult to fully utilize the by-product TCS of the disproportionation reaction of DCS, resulting in the limitation of the yield of silane gas prepared by the disproportionation reaction of DCS.

[0049] 2. The silane production system of the present utility model forms a complete high-purity SiH4 production system by setting a degassing tower, an adsorption device, a purification column, an MCS buffer tank, etc., which cooperate with the reactive distillation device. It improves the production rate of high-purity silane gas and also reduces equipment investment and operation energy consumption, and solves the problem in the prior art that it is difficult to fully utilize the by-product TCS of the disproportionation reaction of DCS, resulting in the limitation of the yield of high-purity silane gas prepared by the disproportionation reaction of DCS. Description of the Drawings

[0050] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings required for the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0051] Figure 1 Structural schematic diagram of the reactive distillation device according to the first embodiment of the present utility model;

[0052] Figure 2 Structural schematic diagram of the silane production system according to the second embodiment of the present utility model.

[0053] Reference numerals: 100 - degassing tower, 101 - degassing tower feed end, 102 - degassing tower upper exhaust end, 103 - degassing tower lower discharge end, 150 - degassing tower condenser, 160 - degassing tower reboiler;

[0054] 200 - device body, 201 - first body discharge end, 202 - second body discharge end, 203 - third body discharge end, 204 - body feed end, 210 - rectifying section, 220 - DCS catalytic reaction section, 221 - pressure plate, 222 - support plate, 224 - catalyst packing, 230 - TCS catalytic reaction section, 240 - stripping section, 250 - body condenser, 260 - body reboiler;

[0055] 300 - adsorption device;

[0056] 400 - purification tower, 401 - first SiH4 discharge end, 402 - second SiH4 discharge end, 403 - MCS discharge end, 450 - purification tower condenser, 460 - purification tower reboiler;

[0057] 500 - MCS buffer tank. Detailed implementation manners

[0058] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.

[0059] The following disclosure provides many different embodiments or examples for implementing different structures of the present utility model. To simplify the disclosure of the present utility model, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present utility model.

[0060] The embodiments of the utility model will be described in detail below with reference to the accompanying drawings.

[0061] Embodiment 1

[0062] In the prior art, the process for producing silane gas that is more commonly used is to prepare silane gas based on the disproportionation reaction of DCS in the improved Siemens process. Although the disproportionation conversion rate of DCS is high, the disproportionation reaction of DCS will by-produce TCS, and the single-pass conversion rate of TCS is relatively low. Since it is difficult to fully utilize the TCS by-produced from the disproportionation reaction of DCS, the yield of producing silane gas by the disproportionation reaction of DCS is limited. Please refer to Figure 1 , the first embodiment provides a DCS reactive distillation device for producing SiH4 and STC using DCS as a raw material, which can improve the conversion rate of TCS by-produced during the disproportionation catalytic reaction of DCS into SiH4, strengthen the utilization of the by-product TCS, thereby improving the yield of producing silane gas using DCS as a raw material, and the process of this DCS reactive distillation device is simple, with less equipment investment and low operating energy consumption at the same time. This DCS reactive distillation device mainly includes: the device body 200 and the DCS catalytic reaction section 220 and the TCS catalytic reaction section 230 arranged inside it.

[0063] As Figure 1 shown in , the device body 200 includes the main structure of a reactive distillation column, and the reactive distillation column is a comprehensive device that combines a disproportionation reactor and a rectifying separator, and can carry out chemical reactions and material separation simultaneously.

[0064] The DCS catalytic reaction section 220 is arranged inside the device body 200. The DCS catalytic reaction section 220 is internally provided with a catalyst for carrying out the catalytic disproportionation reaction of DCS in the device body 200. The main reaction is:

[0065] 3SiH2Cl2→SiH4+2SiHCl3 (Reaction formula ①),

[0066] The TCS catalytic reaction section 230 is arranged inside the device body 200 and is located below the DCS catalytic reaction section 220 so as to be in liquid phase contact with the heavier component TCS. The TCS catalytic reaction section 230 is internally provided with a catalyst, and the catalyst is preferably PA100 macroporous weakly basic anion exchange resin, which is used for carrying out the catalytic disproportionation reaction of TCS in the device body 200. The main reaction is:

[0067] 2SiHCl3→SiH2Cl2+SiCl4 (Reaction formula ②),

[0068] In this embodiment, by controlling the temperature and pressure and taking advantage of the difference in boiling points between DCS and TCS, the TCS in the middle of the apparatus main body 200 is mainly in a liquid state, and the DCS is mainly in a gaseous state. The TCS produced by the disproportionation reaction in the DCS catalytic reaction section 220 moves downward in a liquid state to participate in the reaction in the TCS catalytic reaction section 230; the DCS produced by the disproportionation reaction in the TCS catalytic reaction section 230 moves upward in a gaseous state to participate in the reaction in the DCS catalytic reaction section 220. Therefore, the DCS and TCS in the reactants can be efficiently and continuously cyclically converted in the internal space of the apparatus main body 200. It can be seen from Reaction Formula ① that only 1 molecule of SiH4 can be produced from 3 molecules of DCS, and this reaction is a reversible reaction, and the conversion rate cannot reach 100%. Without considering the reverse reaction, the yield of SiH4 is only 10.56%. This embodiment utilizes Reaction Formula ② in which the disproportionation product TCS of the first step is continuously used for the disproportionation reaction. Substituting Reaction Formula ② into Reaction Formula ①, the overall reaction formula can be obtained: 2SiH2Cl2 → SiH4 + SiCl4. Similarly, without considering the reverse reaction, the yield of SiH4 can reach 15.84% at this time, which is a 50% increase compared to the SiH4 yield of Reaction Formula ①.

[0069] Considering that both the two-step disproportionation reactions combining Reaction Formula ① and Reaction Formula ② are reversible reactions, in this embodiment, during the cyclic conversion process, through the structure of the reactive distillation column itself, the gaseous crude SiH4 produced in the DCS catalytic reaction section 220 moves upward and is continuously withdrawn from the top of the apparatus main body 200, and the liquid-phase STC produced in the TCS catalytic reaction section 230 is continuously withdrawn from the bottom of the apparatus main body 200. The timely withdrawal at the top and the bottom of the column reduces the concentration of the products, thereby promoting the forward progress of Reaction Formula ① and Reaction Formula ②.

[0070] In summary, the DCS reactive distillation apparatus in this embodiment forms a cyclic flow reaction of the reactants between the DCS catalytic reaction section 220 and the TCS catalytic reaction section 230 by arranging the DCS catalytic reaction section 220 above and the TCS catalytic reaction section 230 below in the apparatus main body 200 and cooperating with the control of temperature and pressure. Macroscopically, the disproportionation reaction equation of DCS is changed from 3SiH2Cl2 → SiH4 + 2SiHCl3 to 2SiH2Cl2 → SiH4 + SiCl4, which not only improves the production rate of silane gas, but also reduces the equipment investment and operation energy consumption, and solves the problem in the prior art that it is difficult to make full use of the disproportionation by-product TCS of DCS, resulting in the limitation of the yield of silane gas prepared by the disproportionation reaction of DCS.

[0071] In addition, the apparatus body 200 in this embodiment is further provided with a rectifying section 210 and a stripping section 240. Among them, the rectifying section 210 is arranged above the DCS catalytic reaction section 220. The rectifying section 210 is internally provided with a rectifier (tray or packing). Under the condition of constant pressure, the gas mixture moving upward after the reaction in the DCS catalytic reaction section 220 is purified and separated by temperature control. The main component of the processed gas mixture is SiH4, but it also contains a small amount of MCS. The rectifying section 210 is mainly used to remove the heavy components in SiH4, liquefy and reflux the unreacted DCS and part of MCS so that they can continue to participate in the disproportionation reaction, and the crude SiH4 containing a trace amount of MCS enters the top of the tower in a gaseous state. The stripping section 240 is arranged below the TCS catalytic reaction section 230. The stripping section 240 is internally provided with a stripper (tray or packing). Under the condition of constant pressure, the liquid mixture moving downward after the reaction in the TCS catalytic reaction section 230 is purified and separated by temperature control. The main components of the processed liquid mixture are STC, unreacted TCS, and a small amount of DCS, etc. The stripping section 240 is mainly used to evaporate and lift the unreacted TCS and a small amount of DCS to the upper part of the apparatus body 200 so that they can continue to participate in the reaction, and STC enters the bottom of the tower in a liquid state.

[0072] Moreover, a main condenser 250 is provided at the top of the apparatus body 200, and a main reboiler 260 is provided below the bottom of the apparatus body 200. The apparatus body 200 also has a first main discharge end 201, a second main discharge end 202, a third main discharge end 203, and a main feed end 204. Among them, the main feed end 204 is provided on the side of the apparatus body 200 tower, above the DCS catalytic reaction section 220 and below the rectifying section 210, and is used to introduce liquid-phase DCS so that it can directly enter the DCS catalytic reaction section 220 for reaction. The first main discharge end 201 is connected to the liquid-phase pipeline of the main condenser 250 at the top of the apparatus body 200. The main condenser 250 re-condenses the rectified gas phase into liquid-phase crude SiH4. Through the liquid-phase pipeline of the main condenser 250, a part of the liquid-phase crude SiH4 is used as the top reflux, and the other part is used as the liquid-phase draw. The second main discharge end 202 is connected to the gas-phase pipeline at the top of the apparatus body 200 and is used to draw the rectified gas-phase crude SiH4. At the same time, the third main discharge end 203 is connected to the liquid-phase connection pipe between the bottom of the apparatus body 200 and the main reboiler 260, which is convenient for drawing the liquid-phase by-product with the main component of STC, and the main reboiler 260 provides heat for the apparatus body 200. The main reboiler 260 provides evaporation for the gas-liquid contact, mass transfer, and heat transfer in the tower, so as to evaporate the light components in the stripping section 240 of the apparatus body 200 and lift them to the upper section of the apparatus body 200 for further reaction. It should be noted that in one or more embodiments, one of the first main discharge end 201 and the second main discharge end 202 is selected to be provided, and the crude SiH4 product is drawn only in one way.

[0073] In this embodiment, the structures of the DCS catalytic reaction section 220 and the TCS catalytic reaction section 230 both include a pressure plate 221, a support plate 222, and catalyst packing 224. Among them, the DCS catalytic reaction section 220 and the TCS catalytic reaction section 230 each have a pressure plate 221 and a support plate 222, which are respectively arranged at the top and bottom of the two. Both the pressure plate 221 and the support plate 222 allow the gas phase and the liquid phase to pass through; the catalyst packing 224 is filled between the top pressure plate 221 and the bottom support plate 222 to catalyze the disproportionation reaction of the gas phase and the liquid phase. The catalyst packing 224 is preferably PA100 macroporous weakly basic anion exchange resin. The catalyst packing 224 of the DCS catalytic reaction section 220 and the TCS catalytic reaction section 230 also provides a place for gas-liquid mass transfer and heat transfer in the rectifying column to achieve the rectifying effect.

[0074] Preferably, when the reactive distillation apparatus of this embodiment is in use, the temperature in the apparatus body 200 is preferably maintained at -100°C to -50°C, and the pressure is preferably maintained at 1 to 7 bar.

[0075] Embodiment 2

[0076] Based on the first embodiment, the second embodiment further provides a silane production system. The silane production system in the second embodiment forms a complete high-purity silane gas production system by adding other equipment to cooperate with the reactive distillation device.

[0077] Please refer to Figure 1 - Figure 2 , the silane production system in the second embodiment mainly includes: the reactive distillation device in the first embodiment, as well as a degassing tower 100, an adsorption device 300, a purification tower 400, an MCS buffer tank 500, etc.

[0078] As Figure 2 shown in, the degassing tower 100 is connected to the main body feed end 204 for light component removal and purification. In the degassing tower 100, the hydrogen dissolved in the raw material DCS is analyzed, and the hydrogen and other light component impurities in the introduced liquid-phase DCS raw material are removed by rectification. The degassing tower 100 is provided with a degassing tower feed end 101 for introducing the liquid-phase DCS as the raw material, and a degassing tower upper exhaust end 102, which is connected to the degassing tower condenser 150 at the top of the degassing tower 100, for discharging the light component impurities in the state of non-condensable gas. The degassing tower condenser 150 mainly provides liquid-phase reflux for the top of the degassing tower 100. By providing the liquid-phase reflux for gas-liquid contact, mass transfer and heat transfer in the degassing tower 100, the effect of DCS purification and impurity removal is achieved. In addition, there is also a degassing tower lower discharge end 103, which is arranged on the liquid connection pipe of the degassing tower reboiler 160 at the bottom of the degassing tower 100 and is connected to the main body feed end 204. The degassing tower reboiler 160 is used to provide heat source for the degassing tower 100, facilitating the analysis of hydrogen and light component impurities dissolved in the liquid phase and ensuring the quality of the material drawn from the bottom of the tower. In addition, when in use, the temperature in the degassing tower 100 is preferably maintained at 15°C to 50°C, and the pressure is preferably maintained at 2 to 7 bar.

[0079] The adsorption device 300 is connected to the second main body discharge end 202, and the gaseous crude SiH4 is introduced. The adsorption device 300 is filled with adsorbents, mainly including adsorption resins or activated carbon, etc., for adsorbing and removing solid particle impurities in the gaseous crude SiH4, mainly including B, P and metal impurities, etc.

[0080] The purification column 400 is connected to the first body discharge end 201 or the adsorption device 300, and is used for rectifying and removing the heavy components and impurities containing MCS in the crude SiH4. According to the product requirements, the purification column 400 can be connected to the first body discharge end 201 to directly introduce the liquid-phase crude SiH4; or connected to the adsorption device 300 to introduce the gas-phase crude SiH4 after adsorption and impurity removal. Moreover, the purification column 400 has at least a first SiH4 discharge end 401, a second SiH4 discharge end 402, an MCS discharge end 403, etc. Among them, the first SiH4 discharge end 401 is connected to the liquid-phase pipeline of the purification column condenser 450 at the top of the purification column 400, and is used for extracting the liquid-phase high-purity SiH4; the purification column condenser 450 is used to liquefy the gas-phase SiH4 product at the top of the column. Through the liquid-phase pipeline of the purification column condenser 450, part of the liquid flows back into the top of the column, and the other part is extracted as the liquid-phase SiH4 product. The second SiH4 discharge end 402 is connected to the side of the purification column 400, and can be used to extract the gas-phase high-purity SiH4 product when needed. At the same time, the MCS discharge end 403 is connected to the liquid-phase connection pipe between the bottom of the purification column 400 and the purification column reboiler 460 below the bottom of the column, and is used for extracting the liquid-phase heavy components and impurities containing MCS. In addition, when in use, the temperature in the purification column 400 is preferably maintained at -100°C to -50°C, and the pressure is preferably maintained at 1 to 7 bar.

[0081] The MCS buffer tank 500 is connected to the MCS discharge end 403 of the purification column 400 and the body feed end 204 of the device body 200. The MCS buffer tank 500 is used to collect the liquid-phase MCS mixture extracted from the bottom of the purification column 400, and inert gas can be introduced to transport the liquid-phase heavy components containing MCS back into the device body 200 and then recycled in the system. In addition, the MCS discharge end 403 of the purification column 400 is also connected to the flare. When the production system is abnormal or in an emergency, the materials in the purification column can be led to the flare system for combustion treatment to eliminate potential hazards.

[0082] In this embodiment, the silane production system forms a complete high-purity SiH4 production system through the cooperation of the degassing tower 100, the adsorption device 300, the purification column 400, the MCS buffer tank 500, etc. with the reactive distillation device, improving the output rate of high-purity silane gas, reducing equipment investment and operating energy consumption, and solving the problem in the prior art that it is difficult to fully utilize the TCS by-produced from the disproportionation reaction of DCS, resulting in the limitation of the yield of high-purity silane gas prepared by the disproportionation reaction of DCS.

[0083] The foregoing has shown and described the basic principles, main features and advantages of the present utility model. Those skilled in the art should understand that the present utility model is not limited by the above embodiments. The above embodiments and the descriptions in the specification are only preferred examples of the present utility model and are not used to limit the present utility model. Without departing from the spirit and scope of the present utility model, the present utility model will have various changes and improvements, and these changes and improvements all fall within the scope of the present utility model claimed. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents.

Claims

1. A DCS reactive distillation device, characterized in that: Using DCS as raw material to produce SiH4 and STC, the DCS reactive distillation device comprises: Device body (200); A DCS catalytic reaction section (220) is disposed in the device body (200); and A TCS catalytic reaction section (230) is arranged in the device body (200) and is located below the DCS catalytic reaction section (220); The TCS generated by the disproportionation reaction in the DCS catalytic reaction section (220) moves downward in a liquid state to the TCS catalytic reaction section (230) to participate in the reaction; and the DCS generated by the disproportionation reaction in the TCS catalytic reaction section (230) moves upward in a gaseous state to the DCS catalytic reaction section (220) to participate in the reaction.

2. The DCS reactive distillation device according to claim 1, characterized in that: The device body (200) at least comprises: a rectification section (210), arranged in the device body (200) and located above the DCS catalytic reaction section (220), and used for rectifying and separating the gas mixture moving upward in the device body (200); and The stripping section (240) is arranged in the device body (200) and is located below the TCS catalytic reaction section (230), and is used for distilling and separating the liquid mixture moving downward in the device body (200).

3. The DCS reactive distillation device according to claim 1, characterized in that: The DCS catalytic reaction section (220) and the TCS catalytic reaction section (230) both include: a pressure plate (221), arranged at the top of the DCS catalytic reaction section (220) or the TCS catalytic reaction section (230), allowing a gas phase and a liquid phase to pass through; a support plate (222), disposed at the bottom of the DCS catalytic reaction section (220) or the TCS catalytic reaction section (230), allowing gas phase and liquid phase to pass through; and The catalyst filler (224) is filled between the pressure plate (221) and the support plate (222) and is used to catalyze the disproportionation reaction of the gas phase and the liquid phase.

4. The DCS reactive distillation device according to any one of claims 1 to 3, characterized in that: The device body (200) at least comprises: A body condenser (250) is arranged at the top of the device body (200); and The main body reboiler (260) is arranged below the tower kettle of the device main body (200).

5. The DCS reactive distillation device according to claim 4, characterized in that: The device body (200) further comprises at least: A body feed end (204) is arranged on the tower side of the device body (200) and located above the DCS catalytic reaction section (220) for introducing liquid DCS; A first body discharge end (201) is connected to a liquid phase pipeline of the body condenser (250) and is used to extract liquid phase crude SiH4 that is condensed after distillation; The second body discharge end (202) is connected to the gas phase pipeline at the top of the device body (200) and is used to extract the gas phase crude SiH4 after distillation; and The third body discharge end (203) is connected to the liquid phase communication pipe of the tower kettle of the device body (200) and the body reboiler (260), and is used to extract the liquid phase STC.

6. A silane production system for producing SiH4 and STC using DCS as raw material, characterized in that: Include: The DCS reactive distillation device as claimed in claim 5.

7. The silane production system according to claim 6, characterized in that: It also comprises a degassing tower (100), which is connected to the main body feed end (204) and is used for distilling and removing light components and impurities in the DCS raw material introduced.

8. The silane production system according to claim 6, characterized in that: Also includes: An adsorption device (300), connected to the discharge end (202) of the second body, for removing solid particle impurities in the crude SiH4 in the gas phase by adsorption; and The purification tower (400) is connected to the first body discharge end (201) or the adsorption device (300) and is used for distilling and removing heavy components and impurities including MCS in the crude SiH4.

9. The silane production system according to claim 8, characterized in that: The purification tower (400) at least comprises: A first SiH4 discharge end (401) is connected to a liquid phase pipeline of a purification tower condenser (450) at the top of the purification tower (400) for extracting liquid phase SiH4; A second SiH4 discharge port (402) is connected to the tower side of the purification tower (400) and is used to extract gaseous SiH4; and The MCS discharge end (403) is connected to the bottom of the purification tower (400) and the liquid phase communication pipe of the purification tower reboiler (460) below the bottom of the tower, and is used to extract the heavy components and impurities of the MCS contained in the liquid phase.

10. The silane production system according to claim 9, characterized in that: It also includes an MCS buffer tank (500), which is connected to the MCS discharge end (403) and the body feed end (204) of the device body (200). The MCS buffer tank (500) is used to collect liquid-phase MCS and can be introduced with inert gas to transport the liquid-phase MCS into the device body (200).

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