A production system for preparing silane gas by using polysilicon by-product DCS
In a production system for producing silane gas from polysilicon by-product DCS, a preheater removes light component impurities, a silane separation tower separates silane, and heat recovery is utilized. This solves the problems of complex processes, high costs, and low purity in existing technologies, and achieves high-purity, low-cost silane gas production.
Patent Information
- Application Number
- CN202521865676.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-01
- Publication Date
- 2026-08-25
- Estimated Expiration
- 2035-09-01
AI Technical Summary
Existing technologies for preparing silanes suffer from problems such as long process flow, large equipment investment, high safety requirements, high production costs, and low product purity.
Design a production system for producing silane gas using DCS as a byproduct of polycrystalline silicon. The raw material is preheated by a preheater and then light component impurities are removed in a light component removal tower. The liquid generated by the reaction is separated into methanesilane in a silane separation tower, and heat is recovered using multiple heat exchangers. Pressure gauges and thermometers are installed to facilitate operation.
This simplifies the process flow, reduces equipment investment and production costs, improves the purity of silane gas to semiconductor grade, and saves energy consumption.
Smart Images
Figure CN224672673U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of polycrystalline silicon production technology, specifically relating to a production system for preparing silane gas using DCS, a byproduct of polycrystalline silicon. Background Technology
[0002] High-purity silane can be used to manufacture polycrystalline silicon, monocrystalline silicon, microcrystalline silicon, silicon nitride, and various metal silicides. It is also an important electronic specialty gas, widely used in the microelectronics and optoelectronics industries. In recent years, with the rapid development of industries such as photovoltaics and display panels, the demand for silane has grown rapidly, thus making inexpensive and efficient silane production technologies increasingly important.
[0003] There are dozens of methods for preparing silanes. The methods that are practical and can be industrialized mainly include the magnesium silicide method, the lithium hydride reduction of trichlorosilane method, the sodium aluminum hydride reduction of silicon tetrafluoride method, and the chlorosilane disproportionation method.
[0004] Chlorosilane disproportionation method: Industrial silicon powder, silicon tetrachloride, hydrogen chloride, etc., react in a fluidized bed reactor to produce trichlorosilane. Under the action of a catalyst, trichlorosilane undergoes a series of complex disproportionation reactions, gradually transforming into dichlorodihydrosilane, monochlorosilane, and silane. The reaction products are a mixture containing silanes and various chlorosilanes. High-purity silanes are separated through a complex purification process. This process is lengthy, involves many steps, requires significant equipment investment, and involves large quantities of flammable, explosive, and highly corrosive chemicals (chlorosilanes, hydrogen chloride). Operation is complex and requires extremely high safety standards.
[0005] Magnesium silicide reduction method: This method utilizes the reaction of magnesium silicide and ammonium chloride in liquid ammonia solvent to produce silane. Industrial silicon powder and magnesium powder react at high temperature to produce magnesium silicide. The resulting magnesium silicide then reacts with ammonium chloride in liquid ammonia solvent at low temperature to produce silane. The reactants are separated and purified to obtain silane gas. The process is relatively simple, with low investment, and the product purity can meet the requirements of solar energy applications. However, the reaction is carried out in liquid ammonia under harsh conditions (low temperature and high pressure), resulting in high consumption of magnesium powder, high production costs, and relatively low product purity.
[0006] Sodium aluminum hydride method: Silane gas is synthesized by reacting sodium aluminum hydride with silicon tetrafluoride. The crude silane gas produced by the reaction is purified to improve its purity to 6N grade silane gas. This method requires a large amount of metallic sodium and aluminum powder, and the cost is relatively high. Utility Model Content
[0007] The purpose of this invention is to solve the problems of the existing technology and provide a production system for preparing silane gas using a DCS (Distributed Control System) as a byproduct of polycrystalline silicon. The preheater preheats the raw material (whose main component is dichlorosilane) before it is fed into a light component removal tower. The light component removal tower removes light component impurities (which are discharged through a light component discharge pipe). The raw material, after removing light component impurities (including hydrogen, nitrogen, hydrogen chloride, carbon monoxide, and carbon dioxide), flows into a reactor to react and obtain a reaction liquid (dichlorosilane reacts to obtain monochlorosilane, and monochlorosilane reacts to obtain methanesilane). The generated reaction liquid flows into a silane separation tower, where the first heavy component (the first heavy component...) is separated. The silanes (including trichlorosilane and dichlorosilane) flow into the trichlorosilane separation tower. The dichlorosilane and other silanes separated in the trichlorosilane separation tower are returned to the second connecting pipe through the first tower top discharge pipe and then re-enter the reactor. The trichlorosilane separated in the trichlorosilane separation tower is returned to the preheater through the second tower bottom discharge pipe for preheating and primary heat utilization. The first light component (including silane and impurities) in the silane separation tower flows into the product silane tower. The tail gas in the product silane tower is discharged through the second tower top discharge pipe (the tail gas is treated). The heavy impurities in the product silane tower are discharged through the third tower bottom discharge pipe. The pure silane is discharged through the product discharge pipe.
[0008] This utility model is achieved through the following technical solution: A production system for preparing silane gas using a DCS (Distributed Control System) as a byproduct of polycrystalline silicon includes a feed pipe connected to a preheater. The preheater is connected to a light component removal tower via a first connecting pipe. The light component removal tower is equipped with a light component discharge pipe and a second connecting pipe. The second connecting pipe is connected to a reactor. The reactor is connected to a silane separation tower via a fourth connecting pipe. The silane separation tower is equipped with a third connecting pipe and a first bottom discharge pipe. The first bottom discharge pipe is connected to a trichlorosilane separation tower. The trichlorosilane separation tower is equipped with a first top discharge pipe and a second bottom discharge pipe. The first top discharge pipe is connected to the second connecting pipe. The second bottom discharge pipe is connected to the preheater. The preheater is also equipped with a first heat exchange outlet pipe. The third connecting pipe is connected to a product silane tower. The product silane tower is equipped with a second top discharge pipe, a product discharge pipe, and a third bottom discharge pipe.
[0009] Preferably, the product discharge pipe is equipped with a product heater.
[0010] Preferably, the product heater is connected to the first heat exchange outlet tube and the second heat exchange outlet tube.
[0011] Preferably, the preheater and the product heater are shell-and-tube heat exchangers.
[0012] Preferably, the reactor is a fluidized bed reactor.
[0013] Preferably, pressure gauges are installed on the light silane removal tower, silane separation tower, trichlorosilane separation tower, and product silane tower.
[0014] Preferably, thermometers are installed on the light silane removal tower, silane separation tower, trichlorosilane separation tower, and product silane tower.
[0015] Preferably, the light silane removal tower, silane separation tower, trichlorosilane separation tower, and product silane tower are all equipped with reboilers.
[0016] Compared with the prior art, this utility model has the following advantages and beneficial effects: I. This utility model provides a production system for preparing silane gas using DCS as a byproduct of polycrystalline silicon. The preheater preheats the raw material (whose main component is dichlorosilane) before it is fed into a light component removal tower. The light component impurities are removed in the light component removal tower (the light component impurities are discharged through a light component discharge pipe). The raw material after removing the light component impurities (including hydrogen, nitrogen, hydrogen chloride, carbon monoxide, and carbon dioxide, etc.) flows into a reactor to react and obtain a reaction liquid (dichlorosilane reacts to obtain monochlorosilane, and monochlorosilane reacts to obtain methanesilane). The generated reaction liquid flows into a silane separation tower. The first heavy component in the silane separation tower (the first heavy component includes trichlorosilane)... The dichlorosilane and other components (such as dichlorosilane) flow into the trichlorosilane separation tower. The dichlorosilane and other components separated in the trichlorosilane separation tower are returned to the second connecting pipe through the first tower top discharge pipe and then re-enter the reactor. The trichlorosilane separated in the trichlorosilane separation tower is returned to the preheater through the second tower bottom discharge pipe for preheating and primary heat utilization. The first light component (including silane and impurities) in the silane separation tower flows into the product silane tower. The tail gas in the product silane tower is discharged through the second tower top discharge pipe (the tail gas is treated). The heavy impurities in the product silane tower are discharged through the third tower bottom discharge pipe. The pure silane is discharged through the product discharge pipe.
[0017] II. This utility model provides a production system for preparing silane gas using DCS, a byproduct of polycrystalline silicon. Trichlorosilane is preheated by a preheater and then flows into the product heater through the first heat exchange outlet pipe for secondary heat utilization. This reduces the heat required for heating in subsequent production of silane and lowers energy consumption.
[0018] III. The present invention provides a production system for preparing silane gas using a polycrystalline silicon by-product DCS. The setting of pressure gauges and thermometers facilitates operators to adjust the production conditions of the light silane removal tower, silane separation tower, trichlorosilane separation tower and product silane tower.
[0019] IV. This utility model provides a production system for preparing silane gas using a polycrystalline silicon by-product DCS, which avoids the excessively long production process and high equipment investment of the ordinary chlorosilane disproportionation method, and has low production costs; it makes full use of energy by setting up multiple heat exchangers for cold and hot medium exchange, saving energy consumption; the by-product DCS has high purity, and the produced silane has high purity, improving the quality of silane gas to reach semiconductor grade. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the structure of this utility model; The components are: 1. Feed pipe; 2. Preheater; 3. First connecting pipe; 4. Light component removal tower; 5. Light component discharge pipe; 6. Second connecting pipe; 7. Silane separation tower; 8. Third connecting pipe; 9. First tower bottom discharge pipe; 10. Trichlorosilane separation tower; 11. First tower top discharge pipe; 12. Second tower bottom discharge pipe; 13. First heat exchange outlet pipe; 14. Product silane tower; 15. Second tower top discharge pipe; 16. Product discharge pipe; 17. Third tower bottom discharge pipe; 18. Product heater; 19. Second heat exchange outlet pipe; 20. Reactor; 21. Fourth connecting pipe. Detailed Implementation
[0021] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.
[0022] Example 1 like Figure 1 As shown, a production system for preparing silane gas using a polysilicon byproduct DCS includes a feed pipe 1 connected to a preheater 2. The preheater 2 is connected to a light component removal tower 4 via a first connecting pipe 3. The light component removal tower 4 is equipped with a light component discharge pipe 5 and a second connecting pipe 6, which is connected to a reactor 20. The reactor 20 is connected to a silane separation tower 7 via a fourth connecting pipe 21. The silane separation tower 7 is equipped with a third connecting pipe 8 and a first tower bottom discharge pipe 9. The discharge pipe 9 is connected to the trichlorosilane separation tower 10, which is equipped with a first top discharge pipe 11 and a second bottom discharge pipe 12. The first top discharge pipe 11 is connected to the second connecting pipe 6, and the second bottom discharge pipe 12 is connected to the preheater 2. The preheater 2 is also equipped with a first heat exchange outlet pipe 13. The third connecting pipe 8 is connected to the product silane tower 14, which is equipped with a second top discharge pipe 15, a product discharge pipe 16, and a third bottom discharge pipe 17.
[0023] Example 2 like Figure 1As shown, a production system for preparing silane gas using a polysilicon byproduct DCS includes a feed pipe 1 connected to a preheater 2. The preheater 2 is connected to a light component removal tower 4 via a first connecting pipe 3. The light component removal tower 4 is equipped with a light component discharge pipe 5 and a second connecting pipe 6, which is connected to a reactor 20. The reactor 20 is connected to a silane separation tower 7 via a fourth connecting pipe 21. The silane separation tower 7 is equipped with a third connecting pipe 8 and a first tower bottom discharge pipe 9. The discharge pipe 9 is connected to the trichlorosilane separation tower 10, which is equipped with a first top discharge pipe 11 and a second bottom discharge pipe 12. The first top discharge pipe 11 is connected to the second connecting pipe 6, and the second bottom discharge pipe 12 is connected to the preheater 2. The preheater 2 is also equipped with a first heat exchange outlet pipe 13. The third connecting pipe 8 is connected to the product silane tower 14, which is equipped with a second top discharge pipe 15, a product discharge pipe 16, and a third bottom discharge pipe 17.
[0024] The product discharge pipe 16 is equipped with a product heater 18.
[0025] The product heater 18 is connected to the first heat exchange outlet tube 13 and the second heat exchange outlet tube 19.
[0026] The preheater 2 and the product heater 18 are shell-and-tube heat exchangers.
[0027] The reactor 20 is a fluidized bed reactor 20.
[0028] Pressure gauges are installed on the light silane removal tower 4, the silane separation tower 7, the trichlorosilane separation tower 10, and the product silane tower 14.
[0029] Thermometers are installed on the light silane removal tower 4, silane separation tower 7, trichlorosilane separation tower 10 and product silane tower 14.
[0030] Reboilers are provided on the light silane removal tower 4, silane separation tower 7, trichlorosilane separation tower 10, and product silane tower 14.
[0031] Compared with the prior art, this utility model has the following advantages and beneficial effects: I. This utility model provides a production system for preparing silane gas using a DCS (Distributed Control System) as a byproduct of polycrystalline silicon. The preheater 2 preheats the raw material (whose main component is dichlorosilane) and then feeds it into a light component removal tower 4. The light component removal tower 4 removes light component impurities (which are discharged through a light component discharge pipe 5). The raw material after removing light component impurities (including hydrogen, nitrogen, hydrogen chloride, carbon monoxide, and carbon dioxide, etc.) flows into a reactor 20 to react and obtain a reaction liquid (dichlorosilane reacts to obtain monochlorosilane, and monochlorosilane reacts to obtain methanesilane). The generated reaction liquid flows into a silane separation tower 7. The first heavy component in the silane separation tower 7 (which includes trichlorosilane and dichlorosilane, etc.) flows into… In the trichlorosilane separation tower 10, dichlorosilane and other substances separated in the trichlorosilane separation tower 10 are returned to the second connecting pipe 6 through the first tower top discharge pipe 11 and then re-enter the reactor 20; the trichlorosilane separated in the trichlorosilane separation tower 10 is returned to the preheater 2 through the second tower bottom discharge pipe 12 for preheating and primary heat utilization; the first light component (the first light component includes silane and impurities) in the silane separation tower 7 flows into the product silane tower 14, and the tail gas is discharged through the second tower top discharge pipe 15 in the product silane tower 14 (the tail gas is treated), and the heavy impurities are removed through the third tower bottom discharge pipe 17 in the product silane tower 14, and the pure silane is discharged through the product discharge pipe 16.
[0032] II. The present invention provides a production system for preparing silane gas using DCS byproducts of polycrystalline silicon. Trichlorosilane is preheated by the preheater 2 and then flows into the product heater 18 through the first heat exchange outlet pipe 13 for secondary heat utilization. This reduces the heat required for heating in the subsequent production of silane and lowers energy consumption.
[0033] III. The present invention provides a production system for preparing silane gas using a polycrystalline silicon by-product DCS. The setting of pressure gauges and thermometers facilitates operators to adjust the production conditions of the light-light separation tower 4, silane separation tower 7, trichlorosilane separation tower 10 and product silane tower 14.
[0034] IV. This utility model provides a production system for preparing silane gas using a polycrystalline silicon by-product DCS, which avoids the excessively long production process and high equipment investment of the ordinary chlorosilane disproportionation method, and has low production costs; it makes full use of energy by setting up multiple heat exchangers for cold and hot medium exchange, saving energy consumption; the by-product DCS has high purity, and the produced silane has high purity, improving the quality of silane gas to reach semiconductor grade.
[0035] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present utility model shall fall within the protection scope of the present utility model.
Claims
1. A production system for preparing silane gas using a DCS (Distributed Control System) as a byproduct of polycrystalline silicon production, characterized in that: The system includes a feed pipe (1) connected to a preheater (2), which is connected to a light component removal tower (4) via a first connecting pipe (3). The light component removal tower (4) is equipped with a light component discharge pipe (5) and a second connecting pipe (6), which is connected to a reactor (20). The reactor (20) is connected to a silane separation tower (7) via a fourth connecting pipe (21). The silane separation tower (7) is equipped with a third connecting pipe (8) and a first tower bottom discharge pipe (9), which separates trichlorosilane from... The trichlorosilane separation tower (10) is connected to the tower. The tower is equipped with a first top discharge pipe (11) and a second bottom discharge pipe (12). The first top discharge pipe (11) is connected to the second connecting pipe (6). The second bottom discharge pipe (12) is connected to the preheater (2). The preheater (2) is also equipped with a first heat exchange outlet pipe (13). The third connecting pipe (8) is connected to the product silane tower (14). The product silane tower (14) is equipped with a second top discharge pipe (15), a product discharge pipe (16), and a third bottom discharge pipe (17).
2. The production system for preparing silane gas using a polycrystalline silicon by-product DCS according to claim 1, characterized in that: A product heater (18) is provided on the product discharge pipe (16).
3. A production system for preparing silane gas using a polycrystalline silicon by-product DCS according to claim 2, characterized in that: The product heater (18) is connected to the first heat exchange outlet pipe (13) and the second heat exchange outlet pipe (19).
4. A production system for preparing silane gas using a polycrystalline silicon by-product DCS according to claim 3, characterized in that: The preheater (2) and the product heater (18) are shell-and-tube heat exchangers.
5. A production system for preparing silane gas using a polycrystalline silicon by-product DCS according to claim 1, characterized in that: The reactor (20) is a fluidized bed reactor.
6. A production system for preparing silane gas using a polycrystalline silicon by-product DCS according to claim 1, characterized in that: Pressure gauges are installed on the light removal tower (4), silane separation tower (7), trichlorosilane separation tower (10) and product silane tower (14).
7. A production system for preparing silane gas using a polycrystalline silicon by-product DCS according to claim 1, characterized in that: Thermometers are installed on the light removal tower (4), silane separation tower (7), trichlorosilane separation tower (10) and product silane tower (14).
8. A production system for preparing silane gas using a polycrystalline silicon by-product DCS according to claim 1, characterized in that: The light silane removal tower (4), silane separation tower (7), trichlorosilane separation tower (10) and product silane tower (14) are all equipped with reboilers.