Process and apparatus for the production of silane by the combined catalysis of solid and liquid catalysts of chlorosilane dismutation

Abstract

The application discloses a process and equipment for producing silane by chlorosilane disproportionation with combined solid catalyst and liquid catalyst, and the process at least comprises a reaction rectification stage catalyzed by a solid catalyst and a reaction and separation stage catalyzed by a liquid catalyst. The process of the application uses the solid catalyst and the liquid catalyst simultaneously, and combines the homogeneous catalytic reaction rectification and the heterogeneous catalytic reaction rectification, so that the rate-controlling step of the disproportionation reaction is first balanced through primary disproportionation, then the generated intermediate product is subjected to secondary disproportionation, and the silane and the silicon tetrachloride are continuously removed, so that the chemical equilibrium is further transferred to the product site, that is, the limited reaction conversion of the very high or all chemical equilibrium is achieved. The chlorosilane disproportionation reaction which is not favorable to the reaction kinetics is strengthened, the reaction is promoted to reach the equilibrium, and the multiple disproportionation is used to improve the reaction conversion rate.

Description

Technical Field

[0001] This invention relates to the technical field of disproportionation of chlorosilanes to produce silanes, and in particular to a process and equipment for the disproportionation of chlorosilanes to produce silanes by combining a solid catalyst and a liquid catalyst. Background Technology

[0002] Rapid industrial development has led to a surge in energy demand, while the non-renewable nature of traditional energy sources has resulted in a supply-demand imbalance. Therefore, finding alternative, environmentally friendly, or renewable energy sources is urgently needed. The most important "green" renewable energy source is solar energy, which is both environmentally friendly and inexhaustible. Converting solar energy into usable energy requires photovoltaic panels, and polysilicon is one of the main raw materials for producing photovoltaic modules. Currently, the primary process for obtaining polysilicon is the Siemens process, used by over 80% of the world's polysilicon manufacturers. However, this process also has drawbacks, such as high energy consumption, high investment, and high pollution. The thermal decomposition of silane to produce electronic-grade polysilicon has attracted greater interest due to its low investment, low energy costs, and minimal environmental pollution during production. Furthermore, silane has wide applications in optoelectronics, microelectronics and nanoelectronics in solar cells, and the semiconductor industry.

[0003] Currently, silanes are mainly prepared through methods such as the catalytic disproportionation of trichlorosilane, the decomposition of magnesium silicide, the reduction of silicon tetrafluoride, and plasma treatment. Compared with the magnesium silicide decomposition method, the trichlorosilane (TCS) disproportionation method is simpler, lower in cost, and has higher industrial safety. The TCS disproportionation method was first proposed by Union Carbide Corporation (UCC) in its patent US4340574. This patent uses fixed-bed disproportionation followed by separation and purification in a distillation column. The problem is that the conversion efficiency is high and the energy consumption is high. Later, process intensification technology was used to combine the reaction and distillation into one, overcoming the limitation of chemical reaction equilibrium. It was proposed to use chlorosilane as raw material and purify it into high-purity silane through reactive distillation. The disadvantage of this method is that an expensive refrigerant is required at the top of the column to condense the silane.

[0004] The preparation of silanes by the disproportionation of chlorosilanes involves three steps:

[0005]

[0006]

[0007]

[0008] The three-stage continuous reversible reaction of trichlorosilane disproportionation to silane has very unfavorable reaction kinetics, with a thermodynamic conversion rate close to zero. Its components are both reactants and intermediates, and the coupling between substances is very high. Among them, reaction (1) has the slowest reaction rate and is the rate-determining step of the reaction. Thermodynamic calculations show that the enthalpy change of reaction (1) is greater than 0, and high temperature is favorable for the reaction to proceed in the forward direction.

[0009] Among the various organic and inorganic compounds that can catalyze TCS disproportionation, there is particular interest in anion exchange resins with chemically inert matrices possessing multiple functional groups and large specific surface areas. Currently, catalysts for TCS disproportionation reactions are mainly based on styrene-divinylbenzene (ST / DVB) ion exchange resins and modified resins containing strong basic functional groups (ammonium groups) in chlorine form. The most commonly used TCS catalysts in industry are Amberlyst A-21Dry and Amberlite IRA-400, whose main drawback is poor thermal stability, limited to 80°C, thus restricting the kinetic reaction rate (1)-(3). Given these limitations, we focus on studying high-temperature resistant catalysts. Several types of catalysts have been used to achieve this goal, such as amines, amine salts, amine complexes, nitrogen-containing Lewis acids, and nitriles, which are beneficial for accelerating the exchange of hydrogen and halogens. These catalysts can catalyze the disproportionation of chlorosilanes at higher temperatures, increasing the catalytic reaction rate. However, liquid catalysts can introduce impurities into the products, and the use of organic homogeneous catalysts containing nitrogen atoms as electron donor pairs makes it difficult to separate the reaction mixture and products. Summary of the Invention

[0010] The purpose of this invention is to address the problems of low conversion rate of chlorosilanes in a single reaction and difficulty in separating homogeneous catalysts after the reaction in the existing technology, and to provide a process for the disproportionation of chlorosilanes to produce silanes by combining solid catalysts and liquid catalysts.

[0011] Another objective of this invention is to provide a silane production apparatus for the combined catalytic disproportionation of chlorosilanes to produce silanes using a solid catalyst and a liquid catalyst.

[0012] The technical solution adopted to achieve the purpose of this invention is:

[0013] A process for the disproportionation of chlorosilanes to produce silanes by co-catalyzing a solid catalyst and a liquid catalyst, comprising at least a reactive distillation stage catalyzed by a solid catalyst and a reaction and separation stage catalyzed by a liquid catalyst; including the following steps:

[0014] Step 1: The preheated chlorosilane is passed into a first reaction vessel containing a first catalyst to carry out a first disproportionation reaction at a first pressure and a first temperature to obtain the first product.

[0015] Step 2: Perform a first separation on the first product obtained in Step 1 to separate silicon tetrachloride and an intermediate product;

[0016] Step 3: The intermediate product obtained in Step 2 is passed into a second reaction vessel containing a second catalyst to carry out a second disproportionation reaction at a second pressure and a second temperature to obtain the second product.

[0017] Step 4: The second product obtained in step 3 is subjected to a second separation to obtain silicon tetrachloride and silane. Alternatively, the light phase product after the second separation is subjected to a third disproportionation reaction. The conditions for the third disproportionation reaction are the same as those for the first disproportionation reaction. The third product of the third disproportionation reaction is separated to obtain silicon tetrachloride and silane.

[0018] When the first disproportionation reaction uses a solid catalyst, the second disproportionation reaction uses a liquid catalyst; when the first disproportionation reaction uses a liquid catalyst, the second disproportionation reaction uses a solid catalyst.

[0019] In the above technical solution, when the first catalyst is a solid catalyst, the first disproportionation reaction in step 1 and the first separation in step 2 are carried out simultaneously, which is the reactive distillation stage. When the second catalyst is a solid catalyst, the second disproportionation reaction in step 3 and the second separation in step 4 are carried out simultaneously, which is the reactive distillation stage.

[0020] In the above technical solution, the solid catalyst is a resin catalyst, preferably A-21Dry or AmberliteIRA-400.

[0021] In the above technical solution, the boiling point of the liquid catalyst is higher than that of silicon tetrachloride; the liquid catalyst is an organic liquid catalyst or ionic liquid catalyst that promotes the disproportionation of chlorosilanes, preferably an imidazole organic catalyst, a quinoline organic catalyst or a pyridine organic catalyst, and more preferably hexamethylphosphoric triamine, 4-methylimidazolium or 8-hydroxyquinoline.

[0022] In the above technical solution, both the first separation and the second separation are carried out by distillation separation. The refrigerant for distillation separation is one or more combinations of circulating water, chilled water, chilled brine, ethylene glycol, ammonia refrigerant, Freon, CO2 refrigerant, ethylene, and liquid nitrogen.

[0023] A silane production apparatus for producing silane by disproportionation of chlorosilane based on a combination of solid and liquid catalysts includes a bubble reactor and a reactive distillation column. The reactive distillation column is provided with at least one reaction section filled with solid catalyst. The stripping section of the reactive distillation column is connected to a reboiler at the bottom of the reactive distillation column, and the top of the reactive distillation column is connected to a condenser.

[0024] The preheated chlorosilane is transported through a pipeline to the feed inlet of the bubbling reactor, the outlet of the bubbling reactor is connected to the bottom of the reactive distillation column, the outlet of the reboiler at the bottom of the reactive distillation column is connected to the outlet of silicon tetrachloride, and the outlet of the condenser of the reactive distillation column is connected to the rectification section of the reactive distillation column and the outlet of the silane, respectively.

[0025] A silane production apparatus for the disproportionation of chlorosilanes to silanes based on the combined catalytic action of solid and liquid catalysts includes a bubble reactor, a reactive distillation column, and a distillation purification column. The reactive distillation column has at least one reaction section filled with a solid catalyst. The stripping section of the reactive distillation column is connected to a reboiler at the bottom of the column. The top of the column is connected to a condenser. The purification column is connected to a mid-section reboiler and a condenser at the top.

[0026] The preheated chlorosilane is transported through a pipeline to the inlet of the bubbling reactor. The outlet of the bubbling reactor is connected to the distillation purification column. A mid-section reboiler is connected to the middle section of the distillation purification column. The outlet of the mid-section reboiler outputs silicon tetrachloride. The outlet of the top of the distillation purification column is connected to the inlet of the distillation purification column condenser. The outlet of the distillation purification column condenser is connected to both the rectification section of the distillation purification column and the reaction section of the reactive distillation column. The top of the reactive distillation column is connected to the reactive distillation column condenser to output silane. The stripping section of the reactive distillation column is connected to the bottom reboiler of the reactive distillation column. The outlet of the bottom reboiler of the reactive distillation column outputs silicon tetrachloride.

[0027] Alternatively, the preheated chlorosilane is piped to the reaction section of a reactive distillation column. The side outlet of the reactive distillation column is connected to the inlet of a bubbling reactor, and the outlet of the bubbling reactor is connected to the distillation purification column. A middle section reboiler is connected to the middle section of the distillation purification column, and silicon tetrachloride is output from the outlet of the middle section reboiler. The top outlet of the distillation purification column is connected to the inlet of the distillation purification column condenser, and the outlet of the distillation purification column condenser is connected to the reaction section of the reactive distillation column. The top of the reactive distillation column is connected to the reactive distillation column condenser, and the outlet of the reactive distillation column condenser is connected to both the silane outlet and the rectification section of the reactive distillation column. The stripping section of the reactive distillation column is connected to the bottom reboiler of the reactive distillation column, and silicon tetrachloride is output from the outlet of the bottom reboiler of the reactive distillation column.

[0028] Alternatively, the preheated chlorosilane is piped to the reaction section of a reactive distillation column. The top of the reactive distillation column is connected to a condenser, and the outlet of the condenser is connected to the inlet of a bubbling reactor and the rectification section of the column. The stripping section is connected to a reboiler at the bottom of the column, and silicon tetrachloride is discharged from the reboiler. The outlet of the bubbling reactor is connected to the distillation purification column, and a mid-section reboiler is connected to the middle section. Silicon tetrachloride is discharged from the reboiler. The outlet of the top of the distillation purification column is connected to the inlet of the condenser, and the outlet of the condenser is connected to the rectification section and the silane outlet of the column.

[0029] In the above technical solution, the pressure inside the distillation purification column is higher than the pressure inside the reactive distillation column.

[0030] In the above technical solution, the bubbling reactor is equipped with a heating jacket or uses external heating;

[0031] One or more baffles are installed inside the bubbling reactor to increase the contact time between chlorosilane and liquid catalyst;

[0032] Silyl chloride or intermediate products are introduced into the liquid catalyst from the bottom of the bubbling reactor for bubbling reaction. The temperature of the bubbling reaction is lower than the boiling point of the liquid catalyst at that pressure to avoid mixing of the catalyst with the reaction products.

[0033] In the above technical solution, the reactive distillation column adopts one or more mid-section reflux for energy-saving modification;

[0034] The reactive distillation column is equipped with one or more reaction sections filled with solid catalysts.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] 1. The process of this invention uses both solid and liquid catalysts, combining homogeneous and heterogeneous catalytic reactive distillation. First, a primary disproportionation reaction is initiated to bring the rate-determining step of the disproportionation reaction to equilibrium. Then, the resulting intermediate product undergoes a secondary disproportionation, continuously removing silanes and silicon tetrachloride, further shifting the chemical equilibrium to the product site, thus achieving a very high or complete chemical equilibrium in a limited reaction conversion. This process enhances the kineticly unfavorable disproportionation reaction of chlorosilanes, promoting equilibrium. The advantage of increasing reaction conversion through multiple disproportionations, combined with distillation purification, not only reduces equipment investment but also overcomes the problem of low reversible reaction conversion in fixed-bed reactors.

[0037] 2. Compared with the traditional heterogeneous reactive distillation disproportionation process, the process of this invention uses a liquid catalyst for homogeneous catalysis in the reactive distillation column. This overcomes the problem that the thermal stability of traditional resin catalysts prevents the increase of the disproportionation reaction rate of chlorosilanes by raising the temperature. The homogeneous catalyst can carry out catalytic disproportionation at a higher temperature of 100-250℃. Pressurization and high temperature are beneficial to accelerate the forward disproportionation reaction and enhance the reaction. The increase in pressure inside the column will correspondingly increase the temperature of the condenser at the top of the column, ultimately saving more than 70% of cryogenic refrigerant and reducing operating costs.

[0038] 3. When the catalytic capacity of the original solid catalyst with poor thermal stability decays, the process of this invention supports the introduction of homogeneous liquid catalysis as a supplement to the original tower, achieving efficient industrial production of silanes without changing the original process. Compared with the traditional fixed-bed multi-step disproportionation process, the equipment of this invention is simplified, the process is reasonable, and the equipment investment cost is low.

[0039] 4. This invention uses a high-boiling-point liquid catalyst and employs a bubbling method to induce the disproportionation reaction of chlorosilanes, which greatly reduces the problem of mixing between the catalyst and the reaction products and overcomes the disadvantage of difficult separation of mixtures.

[0040] 5. In the apparatus of the present invention, the raw material is fed from the bottom into a heated bubbling reactor, where it comes into full contact with the liquid catalyst. Then, the reactants and reaction products are separated and purified. The heavy component, silicon tetrachloride, is continuously collected, promoting the reversible reaction towards the generation of more silanes. The light phase components are mixed with chlorosilanes and then further disproportionated and separated to collect silanes and silicon tetrachloride. The apparatus of the present invention can be a homogeneous catalyst reactive distillation followed by a heterogeneous reactive distillation, or a heterogeneous catalyst reactive distillation followed by a homogeneous reactive distillation, or a homogeneous catalysis and a heterogeneous catalysis can be integrated into a single tower device.

[0041] 6. The device of this invention has a reasonable process and is easy to control. By using solid and liquid catalysts in combination, the addition of liquid catalysts reduces the influence of temperature limitation on the reaction rate of traditional resin catalysts, effectively shortens the time for the disproportionation reaction to reach equilibrium, and improves the reaction rate. The conversion rate of the reaction can reach more than 95%, which is an ideal process for the industrial production of silane. Attached Figure Description

[0042] Figure 1 The diagram shown is a schematic diagram of the first type of silane production equipment.

[0043] Figure 2 The diagram shows the structure of the second type of silane production equipment.

[0044] Figure 3 The diagram shows the structure of the third type of silane production equipment.

[0045] Figure 4 The diagram shows the structure of the fourth type of silane production equipment.

[0046] In the diagram: 1-1-First chlorosilane inlet pipe, 1-2-First bubbling reactor, 1-3-First distillation purification column, 1-4-First intermediate reboiler, 1-5-Condenser of the first distillation purification column, 1-6-First reactive distillation column, 1-7-Condenser of the first reactive distillation column, 1-8-First reaction section, 1-9-Reboiler at the bottom of the first reactive distillation column;

[0047] 2-1-Second reactive distillation column, 2-2-Second chlorosilane inlet pipe, 2-3-Second reaction section, 2-4-Second reactive distillation column condenser, 2-5-Second reactive distillation column side outlet pipe, 2-6-Second reactive distillation column bottom reboiler, 2-7-Second distillation purification column condenser, 2-8-Second distillation purification column, 2-9-Second intermediate reboiler, 2-10-Second bubbling reactor;

[0048] 3-1-Third reactive distillation column, 3-2-Third chlorosilane inlet pipe, 3-3-Third reaction section, 3-4-Third reactive distillation column condenser, 3-5-Third reactive distillation column bottom reboiler, 3-6-Third bubbling reactor, 3-7-Third intermediate reboiler, 3-8-Third distillation purification column, 3-9-Third distillation purification column condenser;

[0049] 4-1-Fourth chlorosilane inlet pipe, 4-2-Fourth bubbling reactor, 4-3-Fourth reactive distillation column, 4-4-Fourth reaction section, 4-5-Fourth reactive distillation column condenser, 4-6-Fourth reactive distillation column bottom reboiler. Detailed Implementation

[0050] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0051] A process for the disproportionation of chlorosilanes to produce silanes by co-catalyzing a solid catalyst and a liquid catalyst, comprising at least a reactive distillation stage catalyzed by a solid catalyst and a reaction and separation stage catalyzed by a liquid catalyst; including the following steps:

[0052] Step 1: The preheated chlorosilane is passed into a first reaction vessel containing a first catalyst and subjected to a first disproportionation at a first pressure and a first temperature to obtain the first product.

[0053] Step 2: Perform a first separation on the first product obtained in Step 1 to separate silicon tetrachloride and an intermediate product;

[0054] Step 3: The intermediate product obtained in Step 2 is passed into a second reaction vessel containing a second catalyst to carry out a second disproportionation reaction at a second pressure and a second temperature to obtain the second product.

[0055] Step 4: The second product obtained in step 3 is subjected to a second separation to obtain silicon tetrachloride and silane. Alternatively, the light phase product after the second separation is subjected to a third disproportionation reaction. The conditions for the third disproportionation reaction are the same as those for the first disproportionation reaction. The third product of the third disproportionation reaction is separated to obtain silicon tetrachloride and silane.

[0056] When the first disproportionation reaction uses a solid catalyst, the second disproportionation reaction uses a liquid catalyst; when the first disproportionation reaction uses a liquid catalyst, the second disproportionation reaction uses a solid catalyst.

[0057] Specifically, when the first catalyst is a solid catalyst, the first disproportionation reaction in step 1 and the first separation in step 2 are carried out simultaneously, which is the reactive distillation stage. When the second catalyst is a solid catalyst, the second disproportionation reaction in step 3 and the second separation in step 4 are carried out simultaneously, which is the reactive distillation stage.

[0058] The solid catalyst is a resin catalyst, preferably A-21Dry or Amberlite IRA-400. The boiling point of the liquid catalyst is higher than that of silicon tetrachloride. The liquid catalyst is an organic liquid catalyst or ionic liquid catalyst that promotes the disproportionation of chlorosilanes, preferably an imidazole organic catalyst, a quinoline organic catalyst, or a pyridine organic catalyst, and more preferably hexamethylphosphoric triamine, 4-methylimidazolium, or 8-hydroxyquinoline. Both the first and second separations are carried out by distillation separation. The refrigerant for distillation separation is one or more combinations of circulating water, chilled water, chilled brine, ethylene glycol, ammonia refrigerant, Freon, CO2 refrigerant, ethylene, and liquid nitrogen.

[0059] On the other hand, a silane production apparatus based on the process of jointly catalyzing the disproportionation of chlorosilane to produce silane using the aforementioned solid catalyst and liquid catalyst includes the following four examples.

[0060] The first type of silane production equipment, such as Figure 1As shown, the preheated chlorosilane is conveyed to the inlet of the first bubbling reactor 1-2 through the first chlorosilane inlet pipe 1-1. The outlet of the first bubbling reactor 1-2 is connected to the first distillation purification column 1-3. The middle section of the first distillation purification column 1-3 is connected to the first middle section reboiler 1-4. The outlet of the first middle section reboiler 1-4 outputs silicon tetrachloride. The outlet at the top of the first distillation purification column 1-3 is connected to the inlet of the first distillation purification column condenser 1-5. The outlet of the first distillation purification column condenser 1-5 is connected to the rectification section of the first distillation purification column 1-3 and the first reaction section 1-8 in the first reactive distillation column 1-6, respectively. The top of the first reactive distillation column 1-6 is connected to the first reactive distillation column condenser 1-7 to output silane. The stripping section of the first reactive distillation column 1-6 is connected to the bottom reboiler 1-9 of the first reactive distillation column. The outlet of the bottom reboiler 1-9 of the first reactive distillation column outputs silicon tetrachloride.

[0061] The second type of production equipment, such as Figure 2 As shown, the preheated chlorosilane is transported through the second chlorosilane inlet pipe 2-2 to the second reaction section 2-3 within the second reactive distillation column 2-1. The side outlet pipe 2-5 of the second reactive distillation column is connected to the inlet of the second bubbling reactor 2-10. The outlet of the second bubbling reactor 2-10 is connected to the second distillation purification column 2-8. The second distillation purification column 2-8 is connected to a second intermediate reboiler 2-9. The outlet of the second intermediate reboiler 2-9 outputs silicon tetrachloride. The outlet at the top of the second distillation purification column 2-8 is connected to the second distillation purification column. The feed inlet of the second distillation purification column condenser 2-7 is connected to the second reaction section 2-3 inside the second reactive distillation column 2-1. The top of the second reactive distillation column 2-1 is connected to the second reactive distillation column condenser 2-4. The outlet of the second reactive distillation column condenser 2-4 is connected to the silane outlet and the rectification section of the second reactive distillation column 2-1, respectively. The bottom of the second reactive distillation column 2-1 is connected to the bottom reboiler 2-6 of the second reactive distillation column. The outlet of the bottom reboiler 2-6 of the second reactive distillation column outputs silicon tetrachloride.

[0062] The third type of production equipment, such as Figure 3As shown, the preheated chlorosilane is transported through the third chlorosilane inlet pipe 3-2 to the third reaction section 3-3 within the third reactive distillation column 3-1. The top of the third reactive distillation column 3-1 is connected to the third reactive distillation column condenser 3-4. The outlet of the third reactive distillation column condenser 3-4 is connected to both the inlet of the third bubbling reactor 3-6 and the rectification section of the third reactive distillation column 3-1. The stripping section of the third reactive distillation column 3-1 is connected to the reboiler 3-5 at the bottom of the third reactive distillation column. The outlet of the -5 unit outputs silicon tetrachloride. The outlet of the third bubbling reactor 3-6 is connected to the third distillation purification column 3-8. The middle section of the third distillation purification column 3-8 is connected to the third middle section reboiler 3-7. The outlet of the third middle section reboiler 3-7 outputs silicon tetrachloride. The outlet of the top of the third distillation purification column 3-8 is connected to the inlet of the condenser 3-9 of the third distillation purification column. The outlet of the condenser 3-9 of the third distillation purification column is connected to the rectification section and the silane outlet of the third distillation purification column 3-8, respectively.

[0063] The fourth type of production equipment, such as Figure 4 As shown, the preheated chlorosilane is transported to the inlet of the fourth bubbling reactor 4-2 through the fourth chlorosilane inlet pipe 4-1. The outlet of the fourth bubbling reactor 4-2 is connected to the bottom of the fourth reactive distillation column 4-3. The stripping section of the fourth reactive distillation column 4-3 is connected to the reboiler 4-6 at the bottom of the fourth reactive distillation column. The top of the fourth reactive distillation column 4-3 is connected to the condenser 4-5. The outlet of the reboiler 4-6 at the bottom of the fourth reactive distillation column is connected to the outlet of silicon tetrachloride. The outlet of the condenser 4-5 is connected to both the rectification section and the outlet of the silane in the fourth reactive distillation column 4-3.

[0064] The reactive distillation column employs one or more intermediate reflux sections for energy-saving retrofitting, and the reactive distillation column is equipped with one or more reaction sections filled with solid catalysts.

[0065] The refrigerant used in the condensers of the distillation purification column and the reactive distillation column is one or more combinations of circulating water, chilled water, chilled brine, ethylene glycol, ammonia, Freon, CO2, ethylene, and liquid nitrogen. The pressure inside the distillation purification column is higher than the pressure inside the reactive distillation column.

[0066] The bubbling reactor is equipped with a built-in heating jacket or uses external heating; one or more baffles are set inside the bubbling reactor to increase the contact time between the chlorosilane and the liquid catalyst; the chlorosilane or intermediate product enters from the bottom of the bubbling reactor and reacts in the liquid catalyst, and the reaction temperature is required to be lower than the boiling point of the liquid catalyst at this pressure to avoid mixing of the catalyst and the reaction product.

[0067] Application Example 1

[0068] In this application embodiment, the first catalyst is a liquid catalyst, and the second catalyst is a solid catalyst, selected as follows: Figure 1 The first type of production equipment shown is used for production. It is produced through the following process:

[0069] Step 1, First disproportionation reaction: TCS is preheated to 80℃ and injected at a rate of 10 kmol / h from the first chlorosilane inlet pipe 1-1 into the heated first bubble reactor 1-2. The first bubble reactor 1-2 is loaded with hexamethylphosphoric triamine catalyst. The reaction temperature is 180-200℃ and the pressure is 650 kPa. Trichlorosilane undergoes first disproportionation in the first bubble reactor 1-2 with full contact with the liquid catalyst. The conversion rate of trichlorosilane is about 20%. The small amount of dichlorosilane, monochlorosilane, silane, silicon tetrachloride and the large amount of unreacted trichlorosilane are all fed into the first distillation purification column 1-3 for separation and purification. The temperature range of the first distillation purification column 1-3 is 50-160℃. The pressure of the first distillation purification column condenser 1-5 is 600 kPa. The top temperature of the column can be cooled by circulating water to save low-temperature refrigerant.

[0070] Step 2, First Separation: The heavy component silicon tetrachloride is extracted from the first intermediate reboiler 1-4. The other light components, trichlorosilane, dichlorosilane, monochlorosilane and silane, are partially refluxed to the first distillation purification column 1-3 after passing through the condenser 1-5 of the first distillation purification column to maintain the stable operation of the distillation column, and part of them are used as feed to the first reactive distillation column 1-6. The feed location is the first reaction section 1-8 filled with solid catalyst.

[0071] Step 3, Second Disproportionation Reaction and Second Separation: The intermediate products undergo secondary disproportionation. Dichlorosilane and monochlorosilane can be rapidly disproportionated in the first reaction section 1-8, with a secondary conversion rate exceeding 50%. The first reaction section 1-8 of the first reactive distillation column 1-6 is filled with basic anion exchange resin A-21. The resin is packed in corrosion-resistant and permeable bags, separated from the wire mesh corrugated packing, serving as a separation agent. The temperature of the first reaction section 1-8 is controlled between 70 and 80°C to ensure efficient disproportionation while maintaining catalyst activity. The temperature range of the first reactive distillation column 1-6 is -80 to 110°C. At 2℃, the pressure of the condenser 1-7 in the first reactive distillation column is 350 kPa. Ethylene is used as the low-temperature cold source in the condenser 1-7 of the first reactive distillation column. An intermediate condenser can be installed in the column to save the deep cryogenic refrigerant at the top of the column. The reboiler 1-9 at the bottom of the first reactive distillation column uses 500 kPa steam as the high-temperature heat source. Trichlorosilane, dichlorosilane, monochlorosilane, a small amount of silane and silicon tetrachloride are further disproportionated and separated in the first reactive distillation column 1-6. The final conversion rate of trichlorosilane can be close to 100%. At the top of the column, about 2.49 kmol / h of silane (MS) with a purity of 99% is collected.

[0072] Application Example 2

[0073] The difference between this application example and application example 1 is that the raw material is a DCS preheated to 50°C. Dichlorosilane undergoes disproportionation with the liquid catalyst in the first bubbling reactor 1-2, achieving a primary conversion rate of approximately 50%. The resulting trichlorosilane, dichlorosilane, monochlorosilane, silane, and silicon tetrachloride are all fed into the first distillation purification column 1-3 for separation and purification. The temperature range of the first distillation purification column 1-3 is 35–160°C, and the pressure of the condenser 1-5 of the first distillation purification column is 60 kcal / kg. 0 kPa, the top temperature of the column can be cooled by circulating water; the heavy component silicon tetrachloride is extracted from the first intermediate reboiler 1-4, and the other light components trichlorosilane, dichlorosilane, monochlorosilane and silane are partially refluxed to the first distillation purification column 1-3 after passing through the condenser 1-5 of the first distillation purification column to maintain the stable operation of the distillation column, and part of it is used as feed for the first reactive distillation column 1-6, with the feed location being the first reaction section 1-8 filled with solid catalyst; the first reaction section 1-8 of the first reactive distillation column 1-6 is filled with solid catalyst. The reaction is carried out using alkaline anion exchange resin A-21, which is packed in a corrosion-resistant, permeable bag and separated from the corrugated wire mesh packing to facilitate reaction separation. The temperature of the first reaction section 1-8 is controlled between 70 and 80°C to ensure efficient disproportionation reaction while maintaining catalyst activity. The temperature range of the first reactive distillation column 1-6 is -80 to 112°C, and the pressure of the first reactive distillation column condenser 1-7 is 350 kPa. The first reactive distillation column condenser 1-7 uses ethylene as a low-temperature cold source. The reboiler 1-9 at the bottom of the distillation column uses 500 kPa steam as a high-temperature heat source. Trichlorosilane, dichlorosilane, monochlorosilane, a small amount of silane and silicon tetrachloride are further disproportionated in the first reactive distillation column 1-6, and then separated and purified through the stripping and rectification sections. In this embodiment, the final conversion rate of dichlorosilane can be close to 100%. Silane (MS) with a purity of 99% is collected at the top of the column, and silicon tetrachloride (STC) with a purity of 99% is collected at the bottom of the first reactive distillation column reboiler 1-9.

[0074] Application Example 3

[0075] This application example differs from Application Example 1 in that the raw materials used in this example are a mixture of TCS and DCS preheated to 80°C. The temperature range of the first distillation purification column 1-3 is 30-160°C. Finally, silane (MS) with a purity of 99% is collected from the top of the first reactive distillation column 1-6, and silicon tetrachloride (STC) with a purity of 99% is collected from the reboiler 1-9 at the bottom of the first reactive distillation column.

[0076] Application Example 4

[0077] The difference between this application example and application example 1 is that the first bubbling reactor 1-2 is equipped with a 4-methylimidazolium catalyst, the temperature of the first bubbling reactor 1-2 is 250-280℃, the pressure is 650 kPa, and the temperature range of the first distillation purification column 1-3 is 60-220℃. Finally, 99% pure silane (MS) is collected from the top of the first reactive distillation column 1-6, and 99% pure silicon tetrachloride (STC) is collected from the reboiler 1-9 at the bottom of the first reactive distillation column.

[0078] Application Example 5

[0079] In this application embodiment, the first catalyst is a solid catalyst, and the second catalyst is a liquid catalyst, selected as follows: Figure 2 The second type of production equipment shown is used for production. The process involves the following steps:

[0080] Step 1, First disproportionation reaction: TCS preheated to 80℃ is injected at a rate of 10 kmol / h from the second chlorosilane inlet pipe 2-2 into the second reaction section 2-3 of the second reactive distillation column 2-1, which is filled with a solid catalyst. The disproportionation reaction occurs in the second reaction section 2-3, with a single-stage conversion rate of approximately 25%. The second reaction section 2-3 of the second reactive distillation column 2-1 is filled with basic anion exchange resin A-21, which is packed in a corrosion-resistant, permeable bag, separated from the wire mesh corrugated packing, serving as a reaction separation mechanism. The temperature of the second reaction section 2-3 is controlled between 70 and 80℃ to ensure efficient disproportionation while maintaining catalyst activity. The temperature range of the second reactive distillation column 2-1 is -80 to 112℃, and the pressure of the condenser 2-4 of the second reactive distillation column is 350 kPa.

[0081] Step 2, First Separation: The light component then rises under the influence of the temperature gradient inside the column, and silane (MS) is collected at the top of the column, while silicon tetrachloride (STC) is collected at the bottom of the second reactive distillation column in reboiler 2-6. Ethylene is used as a low-temperature cold source in condenser 2-4 of the second reactive distillation column, and 500 kPa steam is used as a high-temperature heat source in reboiler 2-6 of the second reactive distillation column.

[0082] Step 3, Second disproportionation reaction: In this step, a stream of material is drawn from the second reaction section 2-3 of the second reactive distillation column 2-1, which is filled with solid catalyst, and fed to the bottom of the heated second bubbling reactor 2-10. The material then bubbles from the bottom into the liquid catalyst for another catalytic disproportionation reaction. The second bubbling reactor 2-10 is filled with hexamethylphosphoric acid triamine catalyst. The temperature of the second reactor is 180-200℃ and the pressure is 650 kPa.

[0083] Step 4, Second Separation: The materials trichlorosilane, dichlorosilane, monochlorosilane, silane, and silicon tetrachloride all enter the second distillation purification column 2-8 for separation and purification. The temperature range of the second distillation purification column 2-8 is 50-160℃. The second distillation purification column 2-8 has a second intermediate reboiler 2-9 and a second distillation purification column condenser 2-7. The pressure of the second distillation purification column condenser 2-7 is 600 kPa. The heavy component silicon tetrachloride is continuously extracted from the second intermediate reboiler 2-9, promoting the reversible reaction towards the generation of more silanes. The light component at the top of the column contains trichlorosilane (TCS), dichlorosilane (DCS), monochlorosilane (MCS), a small amount of silane (MS), and silicon tetrachloride (STC).

[0084] Step 5, the third disproportionation reaction and the third separation: the light component at the top of the second distillation purification column 2-8 is fed into the second reactive distillation column 2-1 after passing through the condenser 2-7 of the second distillation purification column. The feed location is the second reaction section 2-3 filled with solid catalyst. Both the reacted and unreacted materials undergo further disproportionation and separation purification in the second reactive distillation column 2-1. The final conversion rate of trichlorosilane can approach 100%, and approximately 2.49 kmol / h of silane (MS) with a purity of 99% is collected at the top of the column.

[0085] Application Example 6

[0086] The difference between this application example and application example 5 is that this application example uses a DCS at 50°C as raw material, and silane (MS) with a purity of 99% is collected from the top of the second reactive distillation column 2-1, and silicon tetrachloride (STC) with a purity of 99% is collected from the reboiler 2-6 at the bottom of the second reactive distillation column.

[0087] Application Example 7

[0088] In this application embodiment, the first catalyst is a liquid catalyst, and the second catalyst is a solid catalyst, selected as follows: Figure 4 The fourth type of production equipment shown is used for production.

[0089] Step 1, the first disproportionation reaction: TCS preheated to 80℃ is injected at a rate of 10 kmol / h from the tetrachlorosilane inlet pipe 4-1 into the heated fourth bubble reactor 4-2. The fourth bubble reactor 4-2 contains a hexamethylphosphoric triamine catalyst, and its temperature is 130–150℃, with a pressure of 350 kPa. Trichlorosilane undergoes disproportionation in the fourth bubble reactor 4-2, fully contacting the liquid catalyst. The resulting small amounts of dichlorosilane, monochlorosilane, silane, silicon tetrachloride, and a large amount of unreacted trichlorosilane are all fed into the fourth reactive distillation column 4-3 for secondary disproportionation, separation, and purification. The temperature range of the fourth reactive distillation column 4-3 is -80℃ to 1℃. At 15℃, the pressure in the condenser 4-5 of the fourth reactive distillation column is 350 kPa. The fourth reaction section 4-4 of the fourth reactive distillation column 4-3 is filled with basic anion exchange resin A-21. The resin is packed in a corrosion-resistant and permeable bag, separated from the wire mesh corrugated packing, which plays a role in reaction separation. The temperature of the fourth reaction section 4-4 is controlled between 70 and 80℃ to ensure the efficient disproportionation reaction and maintain the activity of the catalyst. The heavy component silicon tetrachloride with a purity of 99% is continuously extracted from the reboiler in the fourth middle section, promoting the reversible reaction towards the generation of more silanes. The light components move to the upper part of the fourth reactive distillation column 4-3, and about 2.49 kmol / h of silane (MS) with a purity of 99% is extracted from the top of the column.

[0090] For ease of explanation, spatial relative terms such as “up,” “down,” “left,” and “right” are used in the embodiments to describe the relationship of one element or feature shown in the figures relative to another element or feature. It should be understood that, in addition to the orientations shown in the figures, spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figures is inverted, an element described as being “down” of other elements or features would be positioned “up” of those other elements or features. Therefore, the exemplary term “down” can encompass both up and down orientations. The device may be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0091] Moreover, relational terms such as “first” and “second” are used merely to distinguish one component from another that has the same name, without necessarily requiring or implying any such actual relationship or order between the components.

[0092] The above description is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A process for the disproportionation of chlorosilanes to produce silanes by combining a solid catalyst and a liquid catalyst, characterized in that, It includes at least a reaction distillation stage catalyzed by a solid catalyst and a reaction and separation stage catalyzed by a liquid catalyst; it includes the following steps: Step 1: The preheated chlorosilane is passed into a first reaction vessel containing a first catalyst to carry out a first disproportionation reaction at a first pressure and a first temperature to obtain the first product. Step 2: Perform a first separation on the first product obtained in Step 1 to separate silicon tetrachloride and an intermediate product; Step 3: The intermediate product obtained in Step 2 is passed into a second reaction vessel containing a second catalyst to carry out a second disproportionation reaction at a second pressure and a second temperature to obtain the second product. Step 4: The second product obtained in step 3 is subjected to a second separation to obtain silicon tetrachloride and silane. Alternatively, the light phase product after the second separation is subjected to a third disproportionation reaction. The conditions for the third disproportionation reaction are the same as those for the first disproportionation reaction. The third product of the third disproportionation reaction is separated to obtain silicon tetrachloride and silane. When the first disproportionation reaction uses a solid catalyst, the second disproportionation reaction uses a liquid catalyst; when the first disproportionation reaction uses a liquid catalyst, the second disproportionation reaction uses a solid catalyst.

2. The process for the combined catalytic disproportionation of chlorosilanes to produce silanes using a solid catalyst and a liquid catalyst as described in claim 1, characterized in that, When the first catalyst is a solid catalyst, the first disproportionation reaction in step 1 and the first separation in step 2 are carried out simultaneously, which is the reactive distillation stage. When the second catalyst is a solid catalyst, the second disproportionation reaction in step 3 and the second separation in step 4 are carried out simultaneously, which is the reactive distillation stage.

3. The process for the disproportionation of chlorosilanes to produce silanes by combining a solid catalyst and a liquid catalyst as described in claim 1, characterized in that, The solid catalyst is a resin catalyst.

4. The process for the combined catalytic disproportionation of chlorosilanes to produce silanes using a solid catalyst and a liquid catalyst as described in claim 3, characterized in that, The solid catalyst is either A-21 Dry or Amberlite IRA-400.

5. The process for the combined catalytic disproportionation of chlorosilanes to produce silanes using a solid catalyst and a liquid catalyst as described in claim 1, characterized in that, The boiling point of the liquid catalyst is higher than that of silicon tetrachloride; the liquid catalyst is an organic liquid catalyst or an ionic liquid catalyst that promotes the disproportionation of chlorosilanes.

6. The process for the combined catalytic disproportionation of chlorosilanes to produce silanes using a solid catalyst and a liquid catalyst as described in claim 5, characterized in that, The liquid catalyst is an imidazole organic catalyst, a quinoline organic catalyst, or a pyridine organic catalyst.

7. The process for the combined catalytic disproportionation of chlorosilanes to produce silanes using a solid catalyst and a liquid catalyst as described in claim 1, characterized in that, Both the first and second separations are carried out by distillation separation, and the refrigerant for distillation separation is one or more combinations of circulating water, chilled water, chilled brine, ethylene glycol, ammonia refrigerant, Freon, CO2 refrigerant, ethylene, and liquid nitrogen.

8. A silane production apparatus based on the process of jointly catalyzing the disproportionation of chlorosilanes to produce silanes using a solid catalyst and a liquid catalyst as described in claim 1, characterized in that, It includes a bubbling reactor and a reactive distillation column. The reactive distillation column is provided with at least one reaction section filled with a solid catalyst. The stripping section of the reactive distillation column is connected to a reboiler at the bottom of the reactive distillation column, and the top of the reactive distillation column is connected to a condenser. The preheated chlorosilane is transported through a pipeline to the feed inlet of the bubbling reactor, the outlet of the bubbling reactor is connected to the bottom of the reactive distillation column, the outlet of the reboiler at the bottom of the reactive distillation column is connected to the outlet of silicon tetrachloride, and the outlet of the condenser of the reactive distillation column is connected to the rectification section of the reactive distillation column and the outlet of the silane, respectively.

9. A silane production apparatus based on the process of jointly catalyzing the disproportionation of chlorosilanes to produce silanes using a solid catalyst and a liquid catalyst as described in claim 1, characterized in that, The system includes a bubbling reactor, a reactive distillation column, and a distillation purification column. The reactive distillation column has at least one reaction section filled with a solid catalyst. The stripping section of the reactive distillation column is connected to a bottom reboiler. The top of the reactive distillation column is connected to a condenser. The distillation purification column is connected to a middle reboiler. The top of the distillation purification column is also equipped with a condenser. The preheated chlorosilane is transported through a pipeline to the inlet of the bubbling reactor. The outlet of the bubbling reactor is connected to the distillation purification column. A mid-section reboiler is connected to the middle section of the distillation purification column. The outlet of the mid-section reboiler outputs silicon tetrachloride. The outlet of the top of the distillation purification column is connected to the inlet of the distillation purification column condenser. The outlet of the distillation purification column condenser is connected to both the rectification section of the distillation purification column and the reaction section of the reactive distillation column. The top of the reactive distillation column is connected to the reactive distillation column condenser to output silane. The stripping section of the reactive distillation column is connected to the bottom reboiler of the reactive distillation column. The outlet of the bottom reboiler of the reactive distillation column outputs silicon tetrachloride. Alternatively, the preheated chlorosilane is piped to the reaction section of a reactive distillation column. The side outlet of the reactive distillation column is connected to the inlet of a bubbling reactor, and the outlet of the bubbling reactor is connected to the distillation purification column. A middle section reboiler is connected to the middle section of the distillation purification column, and silicon tetrachloride is output from the outlet of the middle section reboiler. The top outlet of the distillation purification column is connected to the inlet of the distillation purification column condenser, and the outlet of the distillation purification column condenser is connected to the reaction section of the reactive distillation column. The top of the reactive distillation column is connected to the reactive distillation column condenser, and the outlet of the reactive distillation column condenser is connected to both the silane outlet and the rectification section of the reactive distillation column. The stripping section of the reactive distillation column is connected to the bottom reboiler of the reactive distillation column, and silicon tetrachloride is output from the outlet of the bottom reboiler of the reactive distillation column. Alternatively, the preheated chlorosilane is piped to the reaction section of a reactive distillation column. The top of the reactive distillation column is connected to a condenser, and the outlet of the condenser is connected to the inlet of a bubbling reactor and the rectification section of the column. The stripping section is connected to a reboiler at the bottom of the column, and silicon tetrachloride is discharged from the reboiler. The outlet of the bubbling reactor is connected to the distillation purification column, and a mid-section reboiler is connected to the middle section. Silicon tetrachloride is discharged from the reboiler. The outlet of the top of the distillation purification column is connected to the inlet of the condenser, and the outlet of the condenser is connected to the rectification section and the silane outlet of the column.

10. The silane production apparatus for producing silanes by the combined catalytic disproportionation of chlorosilanes using a solid catalyst and a liquid catalyst as described in claim 9, characterized in that, The pressure inside the distillation purification column is higher than the pressure inside the reactive distillation column.

11. The silane production apparatus according to any one of claims 8-10, characterized in that, The bubbling reactor is equipped with a heating jacket or uses external heating. One or more baffles are installed inside the bubbling reactor to increase the contact time between chlorosilane and liquid catalyst; Silyl chloride or intermediate products are introduced into the liquid catalyst from the bottom of the bubbling reactor for bubbling reaction. The temperature of the bubbling reaction is lower than the boiling point of the liquid catalyst under the reaction pressure to avoid mixing of the catalyst and the reaction products.

12. The silane production apparatus according to any one of claims 8-10, characterized in that, The reactive distillation column employs one or more mid-section reflux sections for energy-saving retrofitting. The reactive distillation column is equipped with one or more reaction sections filled with solid catalysts.

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