Energy-saving preparation system for silane

Abstract

The utility model discloses a kind of energy-saving preparation systems for monosilane, it is related to monosilane preparation technical field, including chlorosilane feed pipe, chlorosilane stripping tower, pre-cooler, adsorption column, reaction tower and product tower connected in turn, reboiler, heat source discharge pipe, heat source feed pipe, heat source pump, the setting of fifth connecting pipe and pre-cooler, effectively utilize heat.The utility model reduces the heat source consumption of monosilane purification tower by comprehensive utilization of cold and heat load, according to 10000 tons / monosilane, can reduce cold and heat medium cost>200 million yuan / year;Low-temperature refrigerant effectively replaces before adsorption column, reduces the refrigerant consumption cost, according to 10000 tons / monosilane, can reduce refrigerant cost>100 million yuan / year;Material before adsorption is carried out ultra-low temperature cooling by pre-cooler before adsorption column, improves adsorption effect, improves quality.

Description

Technical Field

[0001] This utility model belongs to the field of silane preparation technology, specifically relating to an energy-saving preparation system for silane. Background Technology

[0002] Silane, also known as silane or silane hydrodeionization, is a colorless, highly flammable gas with the chemical formula SiH4. It is easily purified and can be precisely controlled, earning it the title of "flowing pure silicon." It is the core raw material for the silane method of producing high-purity crystalline silicon and an important electronic specialty gas that cannot be replaced by other silicon sources. It is widely used in TFT / LCD, crystalline silicon solar cells, semiconductors, and emerging fields such as silicon-carbon anodes and advanced ceramics. Silane practically dominates the entire new energy, semiconductor, and new materials industries. The main methods for silane preparation include the magnesium silicide method, the sodium aluminum hydride method, and the chlorosilane disproportionation method. The chlorosilane disproportionation method involves the hydrogenation reaction of silicon tetrachloride to synthesize trichlorosilane, which then undergoes a three-step reversible disproportionation reaction to produce silane products, with silicon tetrachloride as a byproduct. The silicon tetrachloride is returned to the hydrogenation process. The entire system is a closed-loop cycle with almost no emissions, high atom utilization, and is environmentally friendly, making it very suitable for industrial production and the primary method for silane preparation.

[0003] The chlorosilane disproportionation process was developed by Union Carbide Corporation (UCC) and proposed in patent US4340574. This process involves a multi-step disproportionation reaction in a two-stage fixed bed combined with distillation purification to prepare silanes. Due to the limitation of reaction equilibrium, the single-pass yield of silanes is less than 8 mol.%, a large amount of material needs to be recycled, the process is long, the production efficiency is low, and the energy consumption and investment are large.

[0004] In the silane production process, during the distillation and purification section after the silane reaction, the low boiling point of silane limits the bottom temperature of the silane purification tower, which is controlled at -30℃ to -70℃. Commonly used heat transfer media such as steam, hot water, and circulating water are unsuitable as heat sources. Electric heating or heat transfer oil is typically used to provide the heat source for the purification tower. During silane purification, the heat consumption of the silane purification tower is high; simultaneously, the amount of refrigerant used before the adsorption column is also large. Utility Model Content

[0005] The purpose of this invention is to solve the problems of existing technologies and provide an energy-saving preparation system for silane. The system includes a reboiler, a heat source discharge pipe, a heat source feed pipe, a heat source pump, a fifth connecting pipe, and a precooler, effectively utilizing heat. This invention reduces the heat source consumption of the silane purification tower through the comprehensive utilization of heating and cooling loads. Based on 10,000 tons / ton of silane, it can reduce the cost of heating and cooling media by >2 million RMB / year. The low-temperature refrigerant before the adsorption column is effectively replaced, reducing the cost of refrigerant usage. Based on 10,000 tons / ton of silane, it can reduce the cost of refrigerant by >1 million RMB / year. The precooler before the adsorption column provides ultra-low temperature cooling of the material before adsorption, improving the adsorption effect and quality.

[0006] This utility model is achieved through the following technical solution: An energy-saving preparation system for silane includes a chlorosilane feed pipe connected to a chlorosilane stripping tower. The bottom of the chlorosilane stripping tower is connected to a precooler via a first connecting pipe. The precooler is connected to an adsorption column via a second connecting pipe. The adsorption column is connected to a reaction tower via a third connecting pipe. The top of the reaction tower is connected to a product tower via a fourth connecting pipe. The product tower is equipped with a product tower top discharge pipe and a product tower bottom discharge pipe. The product tower top discharge pipe is connected to a cooler. The cooler is equipped with a tower top reflux pipe and a product discharge pipe. The tower top reflux pipe is connected to the product tower. The product tower bottom discharge pipe is connected to a reboiler. The reboiler is equipped with a tower bottom reflux pipe, a heat source discharge pipe, and a heat source feed pipe. The heat source discharge pipe is connected to a heat source pump. The heat source pump is connected to the precooler via a fifth connecting pipe. The precooler is also connected to the heat source feed pipe.

[0007] Preferably, a light component discharge pipe is provided at the top of the chlorosilane stripping tower.

[0008] Preferably, the reaction tower is equipped with a recombinant component discharge pipe.

[0009] Preferably, the recombinant discharge pipe is connected to the trichlorosilane separation tower.

[0010] Preferably, the trichlorosilane separation tower is equipped with a top discharge pipe and a bottom discharge pipe.

[0011] Preferably, the product tower bottom outlet pipe is connected to the silane outlet pipe containing impurities.

[0012] Compared with the prior art, this utility model has the following advantages and beneficial effects: I. This utility model provides an energy-saving preparation system for silane. Chlorosilane is fed into a chlorosilane stripping tower through a chlorosilane feed pipe. In the stripping tower, light component impurities are removed. The chlorosilane after impurity removal is discharged through a first connecting pipe into a precooler (the precooler uses the material discharged from the heat source outlet pipe of the product tower reboiler as a refrigerant) for precooling. The precooled material is then discharged through a second connecting pipe into an adsorption column for secondary impurity removal. The material after secondary impurity removal is discharged through a third connecting pipe into… In the reaction tower, chlorosilane undergoes a disproportionation reaction to prepare silane. The silane is then discharged into the product tower via a fourth connecting pipe for distillation purification. The purified silane is discharged through the top outlet pipe of the product tower into a cooler for cooling; a portion flows back into the product tower through the top reflux pipe, while the remaining portion is discharged through the product pipe. The purified silane containing impurities is discharged through the bottom outlet pipe of the product tower and heated in a reboiler (the material discharged from the reboiler via the heat source inlet pipe of the precooler serves as the heat medium). This invention reduces the heat source consumption of the silane purification tower through comprehensive utilization of heating and cooling loads. Based on 10,000 tons / ton / silane, it can reduce heating and cooling medium costs by >2 million RMB / year. It effectively replaces the low-temperature refrigerant before the adsorption column, reducing refrigerant usage costs. Based on 10,000 tons / ton / silane, it can reduce refrigerant costs by >1 million RMB / year. The precooler at the adsorption column provides ultra-low temperature cooling of the material before adsorption, improving adsorption efficiency and quality.

[0013] II. The present invention provides an energy-saving preparation system for silane, wherein light component impurities in chlorosilane are discharged through a light component discharge pipe; chlorosilane (including unreacted dichlorosilane and trichlorosilane obtained by reaction) in the reaction tower are discharged through a heavy component discharge pipe; and silane containing impurities separated in the product tower are discharged through a silane containing impurities discharge pipe.

[0014] III. The energy-saving preparation system for silane provided by this utility model shall be used to discharge chlorosilane (including unreacted dichlorosilane and trichlorosilane obtained by reaction) in the column into the trichlorosilane separation column through the recombinant discharge pipe. The dichlorosilane separated in the trichlorosilane separation column shall be discharged through the top discharge pipe of the trichlorosilane separation column. The trichlorosilane separated in the trichlorosilane separation column shall be discharged through the bottom discharge pipe of the trichlorosilane separation column. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the structure of Embodiment 2 of this utility model; The components are as follows: 1. Chlorosilane feed pipe; 2. Chlorosilane stripping tower; 3. First connecting pipe; 4. Precooler; 5. Second connecting pipe; 6. Adsorption column; 7. Third connecting pipe; 8. Reaction tower; 9. Fourth connecting pipe; 10. Product tower; 11. Product tower top discharge pipe; 12. Product tower bottom discharge pipe; 13. Cooler; 14. Tower top reflux pipe; 15. Product discharge pipe; 16. Reboiler; 17. Tower bottom reflux pipe; 18. Heat source discharge pipe; 19. Heat source feed pipe; 20. Heat source pump; 21. Fifth connecting pipe; 22. Light component discharge pipe; 23. Heavy component discharge pipe; 24. Trichlorosilane separation tower; 25. Trichlorosilane separation tower top discharge pipe; 26. Trichlorosilane separation tower bottom discharge pipe; 27. Impurity-containing silane discharge pipe. Detailed Implementation 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.

[0016] Example 1 like Figure 1 As shown, an energy-saving preparation system for silane includes a chlorosilane feed pipe 1, which is connected to a chlorosilane stripping tower 2. The bottom of the chlorosilane stripping tower 2 is connected to a precooler 4 via a first connecting pipe 3. The precooler 4 is connected to an adsorption column 6 via a second connecting pipe 5. The adsorption column 6 is connected to a reaction tower 8 via a third connecting pipe 7. The top of the reaction tower 8 is connected to a product tower 10 via a fourth connecting pipe 9. The product tower 10 is equipped with a product tower top discharge pipe 11 and a product tower bottom discharge pipe 12. The top discharge pipe 11 of the product tower is connected to the cooler 13. The cooler 13 is equipped with a top reflux pipe 14 and a product discharge pipe 15. The top reflux pipe 14 is connected to the product tower 10. The bottom discharge pipe 12 of the product tower is connected to the reboiler 16. The reboiler 16 is equipped with a bottom reflux pipe 17, a heat source discharge pipe 18, and a heat source feed pipe 19. The heat source discharge pipe 18 is connected to the heat source pump 20. The heat source pump 20 is connected to the precooler 4 through a fifth connecting pipe 21. The precooler 4 is also connected to the heat source feed pipe 19.

[0017] Example 2 like Figure 2As shown, an energy-saving preparation system for silane includes a chlorosilane feed pipe 1, which is connected to a chlorosilane stripping tower 2. The bottom of the chlorosilane stripping tower 2 is connected to a precooler 4 via a first connecting pipe 3. The precooler 4 is connected to an adsorption column 6 via a second connecting pipe 5. The adsorption column 6 is connected to a reaction tower 8 via a third connecting pipe 7. The top of the reaction tower 8 is connected to a product tower 10 via a fourth connecting pipe 9. The product tower 10 is equipped with a product tower top discharge pipe 11 and a product tower bottom discharge pipe 12. The top discharge pipe 11 of the product tower is connected to the cooler 13. The cooler 13 is equipped with a top reflux pipe 14 and a product discharge pipe 15. The top reflux pipe 14 is connected to the product tower 10. The bottom discharge pipe 12 of the product tower is connected to the reboiler 16. The reboiler 16 is equipped with a bottom reflux pipe 17, a heat source discharge pipe 18, and a heat source feed pipe 19. The heat source discharge pipe 18 is connected to the heat source pump 20. The heat source pump 20 is connected to the precooler 4 through a fifth connecting pipe 21. The precooler 4 is also connected to the heat source feed pipe 19.

[0018] The chlorosilane stripping tower 2 is equipped with a light component discharge pipe 22 at the top of the tower.

[0019] The reaction tower 8 is equipped with a recombinant component discharge pipe 23 on its bottom.

[0020] The recombinant discharge pipe 23 is connected to the trichlorosilane separation tower 24.

[0021] The trichlorosilane separation tower 24 is equipped with a top discharge pipe 25 and a bottom discharge pipe 26.

[0022] The product tower bottom discharge pipe 12 is connected to the silane discharge pipe 27 containing impurities.

[0023] Compared with the prior art, this utility model has the following advantages and beneficial effects: I. This utility model provides an energy-saving preparation system for silane. Chlorosilane is fed into a chlorosilane stripping tower 2 via a chlorosilane feed pipe 1. Light component impurities are removed in the chlorosilane stripping tower 2. The chlorosilane after light component impurity removal is discharged into a precooler 4 via a first connecting pipe 3 (the material discharged from the heat source outlet pipe 18 of the reboiler 16 of the product tower 10 is used as the refrigerant) for precooling. The precooled material is discharged into an adsorption column 6 via a second connecting pipe 5 for secondary impurity removal. The material after secondary impurity removal is discharged into a reaction tower via a third connecting pipe 7. In step 8, chlorosilane undergoes a disproportionation reaction in reaction tower 8 to prepare silane. The silane is discharged into product tower 10 through the fourth connecting pipe 9 for distillation purification. The purified silane is discharged into cooler 13 through product tower top discharge pipe 11 and cooled. Part of it flows back to product tower 10 through top reflux pipe 14, and the other part is discharged through product pipe. The purified silane containing impurities is discharged through product tower bottom discharge pipe 12 and heated in reboiler 16 (the material discharged from reboiler 16 through the heat source feed pipe 19 of precooler 4 is used as the heat medium). This invention reduces the heat source consumption of the silane purification tower by comprehensively utilizing the cold and heat loads. Based on 10,000 tons / ton of silane, the cost of cold and heat transfer media can be reduced by more than 2 million yuan / year. The low-temperature refrigerant before the adsorption column 6 is effectively replaced, reducing the cost of refrigerant usage. Based on 10,000 tons / ton of silane, the cost of refrigerant can be reduced by more than 1 million yuan / year. The material before adsorption is cooled at ultra-low temperature by the precooler 4 before adsorption column 6, which improves the adsorption effect and improves the quality.

[0024] II. The present invention provides an energy-saving preparation system for silane, wherein light component impurities in chlorosilane are discharged through light component discharge pipe 22; chlorosilane (including unreacted dichlorosilane and trichlorosilane obtained by reaction) in reaction tower 8 are discharged through heavy component discharge pipe 23; and silane containing impurities separated in product tower 10 are discharged through impurity silane discharge pipe 27.

[0025] III. The energy-saving preparation system for silane provided by this utility model shall discharge chlorosilane (including unreacted dichlorosilane and trichlorosilane obtained by reaction, etc.) in the column into the trichlorosilane separation column 24 through the recombinant discharge pipe 23. The dichlorosilane separated in the trichlorosilane separation column 24 shall be discharged through the top discharge pipe 25 of the trichlorosilane separation column. The trichlorosilane separated in the trichlorosilane separation column 24 shall be discharged through the bottom discharge pipe 26 of the trichlorosilane separation column.

[0026] In use, this invention employs an ethylene glycol aqueous solution / dichloromethane as the heat medium in the reboiler 16 to provide heat to the product column 10. After the heat medium's temperature decreases, it is transported to the precooler 4 via the heat source outlet pipe 18, the heat source pump 20, and the fifth connecting pipe 21 to cool the material before adsorption. The temperature of the heat medium flowing out of the reboiler 16 is controlled to -40 to -10°C. This low temperature reduces the amount of chlorosilane entering the adsorption column 6, facilitating adsorption.

[0027] 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. An energy-saving preparation system for silane, characterized in that: The system includes a chlorosilane feed pipe (1), which is connected to a chlorosilane stripping tower (2). The bottom of the chlorosilane stripping tower (2) is connected to a precooler (4) via a first connecting pipe (3). The precooler (4) is connected to an adsorption column (6) via a second connecting pipe (5). The adsorption column (6) is connected to a reaction tower (8) via a third connecting pipe (7). The top of the reaction tower (8) is connected to a product tower (10) via a fourth connecting pipe (9). The product tower (10) is equipped with a product tower top discharge pipe (11) and a product tower bottom discharge pipe (12). The product tower top discharge pipe (11) is connected to a product tower bottom discharge pipe (12). 1) Connected to the cooler (13), the cooler (13) is provided with a tower top reflux pipe (14) and a product discharge pipe (15), the tower top reflux pipe (14) is connected to the product tower (10), the product tower bottom discharge pipe (12) is connected to the reboiler (16), the reboiler (16) is provided with a tower bottom reflux pipe (17), a heat source discharge pipe (18) and a heat source feed pipe (19), the heat source discharge pipe (18) is connected to the heat source pump (20), the heat source pump (20) is connected to the precooler (4) through the fifth connecting pipe (21), and the precooler (4) is also connected to the heat source feed pipe (19).

2. The energy-saving preparation system for silane according to claim 1, characterized in that: The chlorosilane stripping tower (2) is equipped with a light component external discharge pipe (22) at the top of the tower.

3. The energy-saving preparation system for silane according to claim 1, characterized in that: The reaction tower (8) is equipped with a recombinant component discharge pipe (23) on the bottom of the tower.

4. The energy-saving preparation system for silane according to claim 3, characterized in that: The recombinant discharge pipe (23) is connected to the trichlorosilane separation tower (24).

5. The energy-saving preparation system for silane according to claim 4, characterized in that: The trichlorosilane separation tower (24) is equipped with a top discharge pipe (25) and a bottom discharge pipe (26).

6. The energy-saving preparation system for silane according to claim 1, characterized in that: The product tower bottom discharge pipe (12) is connected to the silane discharge pipe (27) containing impurities.

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