Energy-saving silane production and purification system

Abstract

The present application relates to the field of silane production, and discloses an energy-saving silane production and purification system, which comprises a production unit for converting trichlorosilane into silane gas and chlorosilane compounds and performing preliminary separation and treatment on the silane gas and chlorosilane compounds. The present application adopts a disproportionation reaction rectification method, and after pressurization by a compressor, the temperature and pressure of the silane gas and other chlorosilane compounds are increased, and the boiling point of the chlorosilane compounds is increased, so that the chlorosilane compounds are more easily liquefied at a higher temperature, which is helpful to realize more effective condensation and separation in a pre-cooler, and moreover, through the cooling effect of the pre-cooler, part of the chlorosilane compounds is condensed into a liquid state, so as to realize preliminary separation from the gaseous silane gas, part of the impurities is removed in advance, the impurity content entering a silane separation tower is reduced, and the separation efficiency of the separation tower is improved.

Description

Technical Field

[0001] The present invention relates to the field of silane production, in particular to an energy-saving silane production and purification system. Background Art

[0002] Silane gas is a special electronic gas that is widely used in many fields such as photovoltaics, integrated circuits, display panels, solar cells, thin film transistors, advanced ceramics, etc.

[0003] Currently, there are four methods for producing silane: the fluorosilicon method, the chlorosilicon method, the magnesium-silicon method, and the lithium-silicon method. The chlorosilicon method (also known as the disproportionation method) is the primary production process, divided into a two-step method and a reactive distillation method. This method uses trichlorosilane as a raw material and undergoes a disproportionation reaction to produce silane. The two-step method offers advantages such as high product purity and high raw material utilization, but it also suffers from a more complex production process, low reaction conversion rates, and high equipment requirements. Compared to the traditional two-step method, reactive distillation offers advantages such as high reaction conversion rates and relatively low energy consumption, making it suitable for large-scale production. However, it also suffers from high operating energy consumption and a high concentration of trace impurities.

[0004] The present invention improves the product quality of silane on the basis of improving the reactive distillation process, greatly reduces the operating energy consumption of silane production, reduces the amount of refrigerant used, and saves resources. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is that the operating energy consumption of silane production is relatively high.

[0006] The above technical problems are solved by the following technical solutions: The present invention proposes an energy-saving silane production and purification system, comprising:

[0007] A production unit for converting trichlorosilane into silane gas and chlorosilane compounds, and performing preliminary separation treatment on the silane gas and chlorosilane compounds;

[0008] A separation unit, comprising a silane separation tower, for deeply separating the preliminarily treated silane gas from other impurities, including but not limited to monochlorosilane, dichlorosilane, hydrogen, and nitrogen, to improve the purity of the silane;

[0009] The separation tower condenser is used to condense the silane gas discharged from the top of the silane separation tower to achieve liquefaction of silane and separation of impurities;

[0010] A precooler is used to precool the silane gas before the silane separation tower to reduce the temperature of the silane gas and condense some impurities;

[0011] The precooler is connected to the separation tower condenser and is used to receive the refrigerant from the separation tower condenser and use the refrigerant to precool the silane gas;

[0012] A compressor, which is used to pressurize the silane gas before the precooler to increase the pressure of the silane gas;

[0013] A purification unit, used to remove trace impurities from the silane gas and further purify the silane gas through distillation;

[0014] The circulation unit is used for circulating the refrigerant.

[0015] In a preferred embodiment of the energy-saving silane production and purification system of the present invention: the production unit comprises:

[0016] Silane reaction tower, which is used to convert trichlorosilane into silane gas and other chlorosilane compounds;

[0017] A reaction tower reboiler, connected to the silane reaction tower, is used to provide heat to the silane reaction tower to maintain the temperature required for the reaction;

[0018] a first condenser connected to the silane reaction tower and used to condense part of the chlorosilane compounds discharged from the top of the silane reaction tower;

[0019] a second condenser connected to the first condenser for further condensing uncondensed silane gas and other chlorosilane compounds;

[0020] a gas-liquid separation tank connected to the second condenser and used for separating the condensed liquid substance and the uncondensed gaseous silane;

[0021] The outlet of the gas-liquid separation tank is connected to the inlet of the compressor, and is used to transport the separated gaseous silane to the compressor.

[0022] In a preferred embodiment of the energy-saving silane production and purification system of the present invention: the production unit further includes:

[0023] An outlet buffer tank connected to the outlet of the compressor and used to stabilize the pressure of the pressurized silane gas;

[0024] The outlet of the outlet buffer tank is connected to the inlet of the precooler, and is used to transport the pressurized silane gas to the precooler.

[0025] In a preferred embodiment of the energy-saving silane production and purification system of the present invention: the production unit further includes:

[0026] A reaction tower reflux tank, connected to the liquid phase outlets of the first condenser, the second condenser and the precooler, for collecting the condensed liquid chlorosilane and refluxing it to the silane reaction tower;

[0027] A pressure pump is connected to the reflux tank of the reaction tower and is used to pressurize the reflux liquid and then transport it back to the silane reaction tower.

[0028] In a preferred embodiment of the energy-saving silane production and purification system of the present invention, impurities discharged from the bottom of the silane separation tower are refluxed to the silane reaction tower to achieve material recycling.

[0029] In a preferred embodiment of the energy-saving silane production and purification system of the present invention: the purification unit comprises:

[0030] an adsorption column connected to the silane separation tower for adsorbing and removing trace impurities in the silane gas, wherein the trace impurities include boron and phosphorus;

[0031] A silane purification tower, which is used to further purify silane gas by distillation to obtain a high-purity silane product;

[0032] The inlet of the silane purification tower is connected to the outlet of the adsorption column, and is used to receive the silane gas that has undergone adsorption treatment;

[0033] The outlet of the silane purification tower is used to output high-purity silane products.

[0034] In a preferred embodiment of the energy-saving silane production and purification system of the present invention: the purification unit further comprises:

[0035] a purification tower reboiler connected to the silane purification tower and used to provide heat to the silane purification tower and maintain the operating temperature in the tower;

[0036] The purification tower condenser is connected to the silane purification tower and is used for condensing the silane gas discharged from the top of the silane purification tower.

[0037] In a preferred embodiment of the energy-saving silane production and purification system of the present invention: the purification unit further comprises:

[0038] The separation tower reboiler is connected to the reaction tower reboiler and the silane separation tower, and is used to receive the heat medium from the reaction tower reboiler and use the heat medium to provide heat for the silane separation tower, thereby fully utilizing the waste heat.

[0039] In a preferred embodiment of the energy-saving silane production and purification system of the present invention, the adsorption column is filled with an adsorbent, which includes but is not limited to activated carbon, molecular sieves, silica, resin, zeolite or metal oxide, and is used to remove trace impurities in the silane gas.

[0040] In a preferred embodiment of the energy-saving silane production and purification system of the present invention: the circulation unit includes a chilled water device and a chilled water pipeline, and the chilled water device distributes the refrigerant to a first chilled water pipeline and a second chilled water pipeline, wherein the refrigerant in the second chilled water pipeline is subjected to heat exchange in a separation tower condenser and then flows out through a third chilled water pipeline, and the refrigerant in the first chilled water pipeline is subjected to heat exchange in a purification tower condenser and then flows out through a fourth chilled water pipeline.

[0041] In a preferred embodiment of the energy-saving silane production and purification system of the present invention: the third chilled water pipeline and the fourth chilled water pipeline distribute the refrigerant to the fifth chilled water pipeline and the sixth chilled water pipeline, respectively, wherein the refrigerant of the fifth chilled water pipeline undergoes heat exchange through the second condenser and then flows out through the seventh chilled water pipeline, and the refrigerant of the sixth chilled water pipeline undergoes heat exchange through the first condenser and then flows out through the eighth chilled water pipeline.

[0042] In a preferred embodiment of the energy-saving silane production and purification system of the present invention: the seventh chilled water pipeline and the eighth chilled water pipeline distribute the refrigerant to the ninth chilled water pipeline, wherein the refrigerant of the ninth chilled water pipeline undergoes heat exchange in the precooler and then flows out through the tenth chilled water pipeline and returns to the chilled water equipment for recycling.

[0043] The present invention has the beneficial effects of employing a disproportionation reaction distillation method. After pressurization by a compressor, the temperature and pressure of the silane gas and other chlorosilane compounds increase, raising the boiling point of the chlorosilane compounds. This makes the chlorosilane compounds more easily liquefied at higher temperatures, facilitating more efficient condensation and separation in the precooler. Furthermore, the cooling effect of the precooler condenses some of the chlorosilane compounds into a liquid state, thereby achieving preliminary separation from the gaseous silane gas. This allows for the early removal of some impurities, reducing the impurity content entering the silane separation tower, improving the separation efficiency of the separation tower, and reducing the operating load of the separation tower.

[0044] Due to the increased boiling point of chlorosilane compounds, the precooler can achieve condensation at a relatively high temperature, reducing the demand for low-temperature refrigerant, reducing refrigerant consumption, and reducing the energy consumption of the cooling system.

[0045] The precooler uses the waste heat from the separation tower condenser as refrigerant, realizing the recycling of heat and further improving energy utilization efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings of the embodiments of the present invention. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention. Among them:

[0047] Figure 1 Shows a schematic diagram of the connection of separation units in an energy-saving silane production and purification system;

[0048] Figure 2 The diagram shows the distribution of production units, separation units and purification units in an energy-saving silane production and purification system;

[0049] Figure 3 The diagram shows the distribution of production units, separation units, purification units and circulation units in an energy-saving silane production and purification system;

[0050] Figure 4 Shows the overall connection diagram of the energy-saving silane production and purification system;

[0051] Figure 5 A schematic diagram of the circulation of chilled water in the circulation unit of the energy-saving silane production and purification system is shown. DETAILED DESCRIPTION

[0052] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below with reference to specific embodiments and the accompanying drawings.

[0053] The terms used in the present invention are those commonly used in the art in view of the functions of the present invention, but these terms may vary according to the intentions of those skilled in the art, precedents, or new technologies in the art. In addition, specific terms may be selected by the applicant, and in such cases, their detailed meanings will be described in the detailed description of the present invention. Therefore, the terms used in the specification should not be understood as simple names, but rather as the meanings of the terms and the overall description of the present invention.

[0054] Reference Figure 1 and Figure 3 This embodiment provides an energy-saving silane production and purification system, including a production unit 200 and a purification unit 300.

[0055] The production unit 200 is used to convert trichlorosilane into silane gas and chlorosilane compounds and separate the silane gas and chlorosilane compounds. The purification unit 300 is used to remove trace impurities in the silane gas and further purify the silane gas through distillation.

[0056] In the present invention, a silane separation tower 101 , a separation tower condenser 102 , a precooler 103 and a compressor 104 are provided between the production unit 200 and the purification unit 300 .

[0057] The silane separator 101 is used to further separate the pre-treated silane gas from other impurities, including but not limited to monochlorosilane, dichlorosilane, hydrogen, and nitrogen, to improve the purity of the silane. The separator condenser 102 is used to condense the silane gas discharged from the top of the silane separator 101 to liquefy the silane and separate the impurities. The precooler 103 is used to precool the silane gas before the silane separator 101 to lower its temperature and condense some of the impurities. The compressor 104 is used to pressurize the silane gas before the precooler 103 to increase its pressure. The precooler 103 is connected to the separator condenser 102, receiving refrigerant from the separator condenser 102 and using the refrigerant to precool the silane gas.

[0058] Furthermore, after being pressurized by compressor 104, the temperature and pressure of the silane gas and other chlorosilane compounds increase, making it easier for the chlorosilane compounds to condense into a liquid phase during the subsequent condensation process in precooler 103. This improved efficiency of the condensation process can reduce the amount of refrigerant required for condensation, thereby reducing energy consumption. At the same time, the increased pressure condenses the chlorosilane compound gas that would not condense under normal pressure, reducing impurities in the silane gas and achieving a preliminary impurity removal effect. This not only reduces the operating load of the subsequent silane separation tower 101, but also improves the purity of the purified silane.

[0059] Furthermore, the internal pressure of silane separation tower 101 is relatively high, and compressor 104 can stably deliver the separated silane gaseous material to silane separation tower 101, ensuring pressure balance and material flow stability throughout the system. Without compressor 104, the silane pressure would be unstable, affecting the operating efficiency of silane separation tower 101 and product quality.

[0060] During use, the gaseous material mainly composed of silane enters the compressor 104, and is pressurized by the compressor 104, and the gaseous material mainly composed of silane is discharged to the outlet of the compressor 104. The gaseous material discharged from the outlet of the compressor 104 passes through the separation tower condenser 102 and then enters the silane separation tower 101 for deep separation. In the silane separation tower 101, silane and a small amount of materials such as monochlorosilane entrained are separated, and monochlorosilane is discharged from the bottom of the silane separation tower 101. Silane and a small amount of hydrogen, nitrogen and other hydrogen components entrained are extracted from the top of the silane separation tower 101 and first pass through the separation tower condenser 102. After condensation, the silane is condensed into a liquid phase and refluxed into the silane separation tower 101. The small amount of hydrogen and nitrogen that have not been condensed are discharged from the exhaust port of the heat exchanger. High-purity silane is extracted from the side of the silane separation tower 101.

[0061] Reference Figure 2 and Figure 4The production unit 200 includes a silane reaction tower 201, a reaction tower reboiler 202, a first condenser 203, a second condenser 204, and a gas-liquid separation tank 205.

[0062] The silane reaction tower 201 is used to convert trichlorosilane into silane gas and other chlorosilane compounds. A reaction tower reboiler 202 is connected to the silane reaction tower 201 to provide heat to the silane reaction tower 201 and maintain the required reaction temperature. A first condenser 203 is connected to the silane reaction tower 201 to condense some of the chlorosilane compounds discharged from the top of the silane reaction tower 201. A second condenser 204 is connected to the first condenser 203 to further condense uncondensed silane gas and other chlorosilane compounds. A gas-liquid separator 205 is connected to the second condenser 204 to separate the condensed liquid from the uncondensed gaseous silane. The outlet of the gas-liquid separator 205 is connected to the inlet of the compressor 104 to transport the separated gaseous silane to the compressor 104.

[0063] Furthermore, in the silane reaction tower 201, trichlorosilane generates products such as silane gas, monochlorosilane, dichlorosilane and silicon tetrachloride through a disproportionation reaction.

[0064] The reaction tower reboiler 202 promotes the reaction by heating the material at the bottom of the reaction tower, ensuring the continuity and stability of the reaction. Through the heat provided by the reaction tower reboiler 202, the reaction in the reaction tower can be carried out efficiently, ensuring the stable generation of silane.

[0065] The first condenser 203 reduces the temperature of the gaseous product and partially condenses it into liquid, thereby achieving preliminary separation. Through condensation, some high-boiling-point chlorosilane compounds are condensed into liquid, reducing the processing load of subsequent equipment.

[0066] The second condenser 204 ensures the efficient execution of the multi-stage condensation process by further reducing the temperature of the gaseous product, thereby improving the separation efficiency. The multi-stage condensation further reduces the impurity content in the gaseous product and improves the purity of the silane gas.

[0067] The gas-liquid separation tank 205 separates the liquid chlorosilane compound from the gaseous silane gas, reducing the entrainment of liquid impurities. The gas-liquid separation tank 205 not only separates the gas and liquid, but also acts as a buffer for the inlet of the compressor 104 to prevent the compressor 104 from carrying liquid. The gas-liquid separation tank 205 has a dual function.

[0068] Reference Figure 2 and Figure 4 The production unit 200 also includes an outlet buffer tank 207, a reaction tower reflux tank 208, and a pressure pump 209.

[0069] The outlet buffer tank 207 is connected to the outlet of the compressor 104 to stabilize the pressure of the pressurized silane gas. The outlet of the outlet buffer tank 207 is connected to the inlet of the precooler 103 to deliver the pressurized silane gas to the precooler 103. The reaction tower reflux tank 208 is connected to the first condenser 203, the second condenser 204, and the liquid phase outlet of the precooler 103 to collect the condensed liquid chlorosilane and reflux it to the silane reaction tower 201. The pressure pump 209 is connected to the reaction tower reflux tank 208 to pressurize the reflux liquid and deliver it back to the silane reaction tower 201.

[0070] Furthermore, the buffer tank 207 is used to balance the airflow output by the compressor 104, reduce pressure fluctuations, and ensure the stable operation of the precooler 103. The outlet of the buffer tank 207 is connected to the inlet of the precooler 103, and the pressurized silane gas is smoothly delivered to the precooler 103. The stable airflow reduces the impact on the precooler 103 and extends the service life of the equipment. At the same time, after the stable airflow enters the precooler 103, it can cool the silane gas more evenly, thereby more effectively separating liquid impurities and improving the separation efficiency of the subsequent separation tower.

[0071] The reaction tower reflux tank 208 is used to collect the condensed liquid chlorosilane and transport it back to the silane reaction tower 201 through the pressure pump 209 to achieve material recycling. By recycling the liquid chlorosilane, the demand for fresh raw materials is reduced, and the energy consumption of preheating the raw materials is reduced. The refluxed liquid chlorosilane has a certain temperature before entering the silane reaction tower 201, which reduces the heat demand of the reaction tower reboiler 202 and further reduces energy consumption.

[0072] The provision of the pressure pump 209 ensures that the reflux liquid can smoothly enter the silane reaction tower 201 and maintain the pressure and liquid level in the silane reaction tower 201 stable.

[0073] Reference Figure 2 and Figure 4 The purification unit 300 includes an adsorption column 301, a silane purification tower 302, a purification tower reboiler 303, a purification tower condenser 304, and a separation tower reboiler 305.

[0074] The adsorption column 301 is connected to the silane separation tower 101 and is used to adsorb and remove trace impurities in the silane gas, including boron and phosphorus. The silane purification tower 302 is used to further purify the silane gas through distillation to obtain a high-purity silane product. The inlet of the silane purification tower 302 is connected to the outlet of the adsorption column 301 and is used to receive the adsorbed silane gas. The outlet of the silane purification tower 302 is used to output the high-purity silane product. The purification tower reboiler 303 is connected to the silane purification tower 302 and is used to provide heat to the silane purification tower 302 to maintain the operating temperature within the tower. The purification tower condenser 304 is connected to the silane purification tower 302 and is used to condense the silane gas discharged from the top of the silane purification tower 302. The separation tower reboiler 305 is connected to the reaction tower reboiler 202 and the silane separation tower 101 for receiving the heat medium from the reaction tower reboiler 202 and using the heat medium to provide heat for the silane separation tower 101, thereby fully utilizing the waste heat.

[0075] Furthermore, the adsorption column 301 removes trace impurities in the silane gas, ensuring that the silane gas entering the distillation tower has a higher purity. Moreover, after removing the trace impurities, the corrosive impurities in the silane gas are reduced, thereby extending the service life of the silane purification tower 302.

[0076] The silane purification tower 302 is used to further purify the silane gas through distillation to obtain a high-purity silane product. The inlet of the silane purification tower 302 is connected to the outlet of the adsorption column 301, and receives the silane gas that has been adsorbed. Through the distillation process, the impurities in the silane gas are further separated to ensure the purity of the final product.

[0077] The purification tower reboiler 303 heats the material at the bottom of the tower to promote the distillation process in the tower. The configuration of the purification tower reboiler 303 reduces temperature fluctuations and improves the stability of the distillation process.

[0078] The purification tower condenser 304 reduces the temperature of gaseous silane and condenses it into liquid, thereby collecting high-purity silane. The condensed liquid silane has high purity and is easy to collect and store.

[0079] Separator reboiler 305 heats the material at the bottom of the tower to ensure efficient separation within the tower. Separator reboiler 305 is connected to reactor reboiler 202. The heat medium used in reactor reboiler 202 releases heat in reactor reboiler 202 and undergoes pretreatment before entering separator reboiler 305 to release heat. This fully utilizes the waste heat and, through waste heat recovery, reduces heat medium loss and lowers operating costs.

[0080] Furthermore, impurities discharged from the bottom of silane separation tower 101 are refluxed to silane reaction tower 201, enabling material recycling. Impurities discharged from the bottom of the tower primarily consist of unreacted raw materials such as trichlorosilane, silicon dichloride, and silicon monochloride, as well as other byproducts. By returning these impurities to the reaction tower, they can re-enter the reaction, reducing raw material waste.

[0081] Furthermore, the adsorption column 301 is filled with an adsorbent, including but not limited to activated carbon, molecular sieves, silica, resins, zeolites, or metal oxides, for removing trace impurities from the silane gas. The adsorbent filled in the adsorption column 301 can be activated carbon or molecular sieves. The surface functional groups of the activated carbon can bind to impurities such as boron and phosphorus through chemical adsorption, while the molecular sieve can selectively adsorb small molecular impurities that match the pore size, such as boron and phosphorus compounds, through physical adsorption.

[0082] During use, trichlorosilane first enters the silane reaction tower 201, where a disproportionation reaction occurs to generate silane, monochlorosilane, dichlorosilane, trichlorosilane, silicon tetrachloride and other substances. Liquid silicon tetrachloride is separated from the bottom of the silane reaction tower 201, and gaseous substances such as silane, monochlorosilane, dichlorosilane, and trichlorosilane are discharged from the top of the tower and gradually condensed through the first condenser 203 and the second condenser 204. Most of the dichlorosilane in the first condenser 203 is Substances such as chlorosilane and trichlorosilane are condensed into liquid phase and enter the reaction tower reflux tank 208 from the lower liquid pipeline of the first condenser 203. The uncondensed silane and monochlorosilane substances are discharged from the exhaust port of the first condenser 203 and enter the second condenser 204. In the first condenser 203, most of the monochlorosilane is condensed into liquid phase and enters the reaction tower reflux tank 208 from the lower liquid pipeline of the second condenser 204. The uncondensed silane is discharged after passing through the gas-liquid separation tank 205.

[0083] The silane discharged from the gas-liquid separation tank 205 enters the compressor 104. After being pressurized by the compressor 104, the gaseous material mainly composed of silane is discharged to the outlet buffer tank 207. The gaseous material discharged from the top of the outlet buffer tank 207 passes through the precooler 103 and enters the silane separation tower 101 for deep separation. The dichlorosilane, trichlorosilane and other materials in the reaction tower reflux tank 208 are pressurized by the pressure pump 209 and then refluxed to the silane reaction tower 201 for re-reaction. In the silane separation tower 101, the silane and the entrained A small amount of monochlorosilane and other materials are separated, and the monochlorosilane is discharged from the bottom of the silane separation tower 101 and returned to the silane reaction tower 201 for reaction. Silane and a small amount of entrained hydrogen, nitrogen and other hydrogen components are extracted from the top of the silane separation tower 101 and enter the separation tower condenser 102. After heat exchange, the silane is condensed into a liquid phase and refluxed to the silane separation tower 101. The small amount of hydrogen and nitrogen that are not condensed are discharged from the exhaust port of the separation tower condenser 102, and high-purity silane is extracted from the side of the silane separation tower 101.

[0084] The high-purity silane extracted from the side of the silane separation tower 101 enters the adsorption column 301, where trace amounts of impurities such as boron and phosphorus in the high-purity silane are removed. The silane after adsorption and impurity removal enters the silane purification tower 302 for distillation, and high-quality silane is extracted from the side of the silane purification tower 302.

[0085] Reference Figure 5 Next, the recycling of refrigerant will be explained.

[0086] Circulation unit 400 includes a chilled water system 401 and chilled water pipelines. The "refrigerant" (here, the "refrigerant" refers to the heat-exchanged water, which is necessarily hotter than the refrigerant required by the silane production and purification units) that returns to chilled water system 401 after heat exchange, as well as water supplied from the outside, is cooled by chilled water system 401 and then distributed to the various chilled water pipelines for recycling.

[0087] In this embodiment, specifically: the chilled water equipment 401 includes a chilled water tank, a refrigeration unit, a chilled water pump and an internal circulation chilled water pipeline. The chilled water tank is provided with a water supply end, a water return end, a water inlet end and a liquid level meter. The external water enters the chilled water tank through the water supply end, and then passes through the internal circulation chilled water pipeline and is cooled by the refrigeration unit to obtain a refrigerant, and then enters the chilled water tank through the water inlet end, and the refrigerant is distributed to the first chilled water pipeline 402 and the second chilled water pipeline 403.

[0088] The chilled water equipment 401 distributes the refrigerant to the first chilled water pipeline 402 and the second chilled water pipeline 403, wherein the refrigerant in the second chilled water pipeline 403 undergoes heat exchange through the separation tower condenser 102 and then flows out through the third chilled water pipeline 404, and the refrigerant in the first chilled water pipeline 402 undergoes heat exchange through the purification tower condenser 304 and then flows out through the fourth chilled water pipeline 405.

[0089] In this embodiment, the liquefaction temperature of silane is -98°C. Under standard atmospheric pressure, silane will change from gas to liquid at this temperature. Therefore, the refrigerant temperature required by the separation tower condenser 102 and the purification tower condenser 304 needs to be lower than -98°C. Therefore, the temperature range of the refrigerant in the first chilled water pipeline 402 and the second chilled water pipeline 403 is between -120°C and -98°C. After the refrigerant in the first chilled water pipeline 402 and the second chilled water pipeline 403 undergoes heat exchange with the silane gas entering the separation tower condenser 102 and the second chilled water pipeline 403, the refrigerant temperature increases.

[0090] By calculating the heat transfer equation, the temperature of the refrigerant after heat exchange in the separation tower condenser 102 and the second chilled water pipeline 403 can be obtained, wherein the heat transfer equation is:

[0091] ;

[0092] Where Q is the heat transfer rate, U is the heat transfer coefficient, A is the heat transfer area, and ΔT is the temperature difference between the refrigerant and the silane.

[0093] The third chilled water pipeline 404 and the fourth chilled water pipeline 405 distribute the refrigerant to the fifth chilled water pipeline 406 and the sixth chilled water pipeline 407 respectively, wherein the refrigerant in the fifth chilled water pipeline 406 undergoes heat exchange through the second condenser 204 and then flows out through the seventh chilled water pipeline 408, and the refrigerant in the sixth chilled water pipeline 407 undergoes heat exchange through the first condenser 203 and then flows out through the eighth chilled water pipeline 409.

[0094] The refrigerant temperature in the first chilled water line 402 and the second chilled water line 403 ranges from -120°C to -98°C. After heat exchange in the separation tower condenser 102 and the purification tower condenser 304, the refrigerant temperature rises, but still needs to be low enough to meet the condensation requirements of the first condenser 203 and the second condenser 204. The primary task of the first condenser 203 and the second condenser 204 is to condense the gaseous products, so the refrigerant temperature must be below the boiling point of the gaseous products to achieve effective condensation.

[0095] The primary condensers in the first condenser 203 are dichlorosilane and trichlorosilane. Dichlorosilane has a boiling point of approximately 29°C, and trichlorosilane has a boiling point of approximately 54°C. To condense these substances, the refrigerant temperature must be below 29°C, the boiling point of dichlorosilane. Typically, the refrigerant temperature is 10°C to 20°C below the boiling point, so the refrigerant temperature in the first condenser 203 can be controlled below 10°C.

[0096] The second condenser 204 primarily condenses monochlorosilane, which has a boiling point of approximately -13°C. To condense monochlorosilane, the refrigerant temperature must be below -13°C, the boiling point of monochlorosilane. Typically, the refrigerant temperature is 10°C to 20°C below the boiling point, so the refrigerant temperature in the second condenser 204 can be controlled below -20°C.

[0097] After heat exchange between the separation tower condenser 102 and the purification tower condenser 304 , the refrigerant temperature will increase, but can still meet the condensation requirements of the first condenser 203 and the second condenser 204 .

[0098] The seventh chilled water pipeline 408 and the eighth chilled water pipeline 409 distribute the refrigerant to the ninth chilled water pipeline 410 . The refrigerant in the ninth chilled water pipeline 410 undergoes heat exchange in the precooler 103 and then flows out through the tenth chilled water pipeline 411 and returns to the chilled water equipment 401 for recycling.

[0099] The heat medium produced by the precooler 103 can also be first provided to the purification tower reboiler 303 for use, providing heat for the purification tower reboiler 303. At the same time, the purification tower reboiler 303 will preliminarily cool the heat medium produced by the precooler 103, and then output the heat medium after heat exchange in the purification tower reboiler 303 to the chilled water equipment 401, reducing the cooling pressure of the chilled water equipment 401.

[0100] Precooler 103 uses refrigerant from ninth chilled water line 410 to cool the silane material. Because the refrigerant in ninth chilled water line 410 has passed through first condenser 203 and second condenser 204, its maximum temperature may be above -20°C. However, by regulating the pressure, the boiling point of monochlorosilane is increased, allowing the refrigerant in ninth chilled water line 410 to meet the condensation requirements of precooler 103, thereby pre-separating the monochlorosilane.

[0101] Precooler 103 uses the refrigerant from ninth chilled water line 410 to lower the temperature of the silane. This not only pre-cools the silane but also condenses a portion of the monochlorosilane in the silane-based material into a liquid phase, achieving a preliminary separation of silane and monochlorosilane. Because the boiling point of monochlorosilane is higher than that of silane, some monochlorosilane condenses into a liquid phase, while the silane gas remains in a gaseous state. The condensed liquid monochlorosilane can be separated through a pipeline, while the uncondensed silane gas continues to enter the silane separation tower 101. After the pre-cooling process, the impurity content of the silane gas entering the silane separation tower 101 is reduced, reducing the separation load of the silane separation tower 101 and improving separation efficiency.

[0102] The substance mainly condensed in the precooler 103 is monochlorosilane, which has a boiling point of approximately -13°C. Due to the configuration of the compressor 104, the boiling point of monochlorosilane is significantly higher than the boiling point at normal pressure. The relationship between the boiling point and pressure can be determined by the Antoine equation. The Antoine equation is an empirical formula used to describe the relationship between the vapor pressure and temperature of a pure substance. In the present invention, the Antoine equation is used to illustrate the relationship between the boiling point and pressure of monochlorosilane, wherein the Antoine equation is:

[0103] ;

[0104] Where P is pressure, T is temperature, and A, B, and C are the Antoine constants of the substance.

[0105] Table 1 shows the boiling points of silane and monochlorosilane at different atmospheric pressures, which also illustrates the boiling point differences and separation efficiencies of silane and monochlorosilane at different atmospheric pressures.

[0106] Table 1 Boiling points of silane and monochlorosilane at different atmospheric pressures

[0107]

[0108] Among them, according to the temperature of the refrigerant in the ninth chilled water pipe 410, the precooler 103 can be pressurized to a level that can separate monochlorosilane, and silane can be precooled at the same time, that is, the boiling point of silane is lower than the temperature of the refrigerant in the ninth chilled water pipe 410, and the boiling point of monochlorosilane is higher than the temperature of the refrigerant in the ninth chilled water pipe 410. For example, if the temperature of the refrigerant is 10°C, the compressor 104 is started to make the pressure in the precooler 103 at 4 atmospheres. At this time, the boiling point of monochlorosilane is 15°C, and the temperature of the refrigerant can just condense monochlorosilane.

[0109] By monitoring the refrigerant temperature in the ninth chilled water line 410, the horsepower of compressor 104 is dynamically adjusted to maintain optimal separation efficiency and minimize energy consumption. A temperature sensor is installed in the ninth chilled water line 410 to monitor the refrigerant temperature in real time. Based on the refrigerant temperature, the control system dynamically adjusts the horsepower of compressor 104.

[0110] Table 2 illustrates the corresponding relationship between the refrigerant temperature in the ninth chilled water pipeline 410 and the pressure in the precooler 103 .

[0111] Table 2 Different refrigerant temperatures correspond to different pressures in the precooler

[0112]

[0113] Wherein, pressure is the output pressure of compressor 104. Atmospheric pressure is used for practical convenience. Refrigerant temperature is the temperature of the refrigerant in ninth chilled water pipeline 410. Boiling point of monochlorosilane is the boiling point at the corresponding pressure. Boiling point of silane is the boiling point at the corresponding pressure. Compressor horsepower is the horsepower of compressor 104 at the corresponding pressure.

[0114] A high-precision temperature sensor is installed in the ninth chilled water line 410 to monitor the refrigerant temperature in real time. Dynamic adjustment of the horsepower of compressor 104 is achieved through a PLC (Programmable Logic Controller) or DCS (Distributed Control System). If the refrigerant temperature exceeds the boiling point of monochlorosilane, the horsepower of compressor 104 is increased, thereby raising the pressure and raising the boiling point of monochlorosilane. Assuming a refrigerant temperature of 20°C, the corresponding pressure is 0.5 MPa according to the table. At this point, the boiling point of silane is -74°C, and the boiling point of monochlorosilane is 21°C. By adjusting the compressor horsepower, the refrigerant temperature can be kept below the boiling point of monochlorosilane, achieving optimal separation efficiency and minimizing energy consumption. To enhance condensation efficiency, the pressure can be increased to 0.6 MPa, thereby increasing the temperature difference between the refrigerant temperature and the boiling point of monochlorosilane.

[0115] Finally, it should be pointed out that the methods and devices described in detail above are merely embodiments, and those skilled in the art can modify these embodiments in different ways without departing from the scope of the present invention.

Claims

1. An energy-saving silane production and purification system, characterized by: include, A separation unit (100) includes a silane separation tower (101) for deeply separating the preliminarily treated silane gas from other impurities, including but not limited to monochlorosilane, dichlorosilane, hydrogen and nitrogen, to improve the purity of the silane; A separation tower condenser (102) is used to condense the silane gas discharged from the top of the silane separation tower (101) to achieve liquefaction of the silane and separation of impurities; A precooler (103) is used to precool the silane gas before the silane separation tower (101) to reduce the temperature of the silane gas and achieve condensation of some impurities; The precooler (103) is connected to the separation tower condenser (102), and is used to receive the refrigerant from the separation tower condenser (102) and use the refrigerant to precool the silane gas; A compressor (104) is used to pressurize the silane gas before the precooler (103) to increase the pressure of the silane gas; A production unit (200) for converting trichlorosilane into silane gas and chlorosilane compounds, and performing preliminary separation treatment on the silane gas and chlorosilane compounds; A purification unit (300) for removing trace impurities in the silane gas and further purifying the silane gas by distillation; A circulation unit (400) for circulating the refrigerant; The production unit (200) comprises, A silane reaction tower (201) for converting trichlorosilane into silane gas and other chlorosilane compounds; A reaction tower reboiler (202), connected to the silane reaction tower (201), is used to provide heat to the silane reaction tower (201) to maintain the temperature required for the reaction; A first condenser (203), connected to the silane reaction tower (201), for condensing part of the chlorosilane compound discharged from the top of the silane reaction tower (201); a second condenser (204), connected to the first condenser (203), for further condensing uncondensed silane gas and other chlorosilane compounds; a gas-liquid separation tank (205), connected to the second condenser (204), for separating condensed liquid substances from uncondensed gaseous silane; The outlet of the gas-liquid separation tank (205) is connected to the inlet of the compressor (104), and is used to transport the separated gaseous silane to the compressor (104); An outlet buffer tank (207), connected to the outlet of the compressor (104), for stabilizing the pressure of the pressurized silane gas; The outlet of the outlet buffer tank (207) is connected to the inlet of the precooler (103), and is used to transport the pressurized silane gas to the precooler (103).

2. The energy-saving silane production and purification system according to claim 1, characterized in that: The production unit (200) further comprises, A reaction tower reflux tank (208), which is connected to the liquid phase outlet of the first condenser (203), the second condenser (204) and the precooler (103), and is used to collect the condensed liquid chlorosilane and reflux it to the silane reaction tower (201); A pressure pump (209) is connected to the reaction tower reflux tank (208) and is used to pressurize the reflux liquid and then transport it back to the silane reaction tower (201).

3. The energy-saving silane production and purification system according to claim 1 or 2, characterized in that: Impurities discharged from the bottom of the silane separation tower (101) are refluxed to the silane reaction tower (201) to achieve recycling of materials.

4. The energy-saving silane production and purification system according to claim 1 or 2, characterized in that: The purification unit (300) comprises, an adsorption column (301), connected to the silane separation tower (101), for adsorbing and removing trace impurities in the silane gas, wherein the trace impurities include boron and phosphorus; A silane purification tower (302) is used to further purify the silane gas by distillation to obtain a high-purity silane product; The inlet of the silane purification tower (302) is connected to the outlet of the adsorption column (301), and is used to receive the silane gas that has undergone adsorption treatment; The outlet of the silane purification tower (302) is used to output high-purity silane products.

5. The energy-saving silane production and purification system according to claim 4, characterized in that: The purification unit (300) further comprises, A purification tower reboiler (303), which is connected to the silane purification tower (302) and is used to provide heat to the silane purification tower (302) to maintain the operating temperature in the tower; The purification tower condenser (304) is connected to the silane purification tower (302) and is used to condense the silane gas discharged from the top of the silane purification tower (302).

6. The energy-saving silane production and purification system according to claim 5, characterized in that: The purification unit (300) further comprises, The separation tower reboiler (305) is connected to the reaction tower reboiler (202) and the silane separation tower (101), and is used to receive the heat medium from the reaction tower reboiler (202) and use the heat medium to provide heat for the silane separation tower (101), thereby fully utilizing the waste heat.

7. The energy-saving silane production and purification system according to claim 4, characterized in that: The adsorption column (301) is filled with an adsorbent, which includes but is not limited to activated carbon, molecular sieves, silicon dioxide, resin or metal oxide, and is used to remove trace impurities in the silane gas.

8. The energy-saving silane production and purification system according to any one of claims 1, 2, 5, 6, and 7, characterized in that: The circulation unit (400) includes a chilled water device (401) and a chilled water pipeline. The chilled water device (401) distributes the refrigerant to a first chilled water pipeline (402) and a second chilled water pipeline (403). The refrigerant in the second chilled water pipeline (403) undergoes heat exchange in a separation tower condenser (102) and then flows out through a third chilled water pipeline (404). The refrigerant in the first chilled water pipeline (402) undergoes heat exchange in a purification tower condenser (304) and then flows out through a fourth chilled water pipeline (405).

9. The energy-saving silane production and purification system according to claim 8, characterized in that: The third chilled water pipeline (404) and the fourth chilled water pipeline (405) distribute the refrigerant to the fifth chilled water pipeline (406) and the sixth chilled water pipeline (407), respectively, wherein the refrigerant of the fifth chilled water pipeline (406) is subjected to heat exchange in the second condenser (204) and then flows out through the seventh chilled water pipeline (408), and the refrigerant of the sixth chilled water pipeline (407) is subjected to heat exchange in the first condenser (203) and then flows out through the eighth chilled water pipeline (409).

10. The energy-saving silane production and purification system according to claim 9, characterized in that: The seventh chilled water pipeline (408) and the eighth chilled water pipeline (409) distribute the refrigerant to the ninth chilled water pipeline (410), wherein the refrigerant in the ninth chilled water pipeline (410) undergoes heat exchange in the precooler (103), flows out through the tenth chilled water pipeline (411) and returns to the chilled water equipment (401) for recycling.

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