Production system for preparing monosilane gas using chlorosilanes

Abstract

The utility model discloses a production system of preparing methyl silane gas by chlorosilane belongs to methyl silane preparation technical field, and chlorosilane passes through chlorosilane feed and flows through first preheater preheating and enters the light component impurity removal in the light component removal tower, and the chlorosilane after light component removal passes through first tower bottom discharge pipe and flows through first cooler cooling and enters the adsorption column and carries out secondary impurity removal, and the chlorosilane after secondary impurity removal flows into the reaction tower in the second connecting pipe and carries out the reaction, and the overhead liquid of reaction tower is condensed after third condenser and carries out third condensation, and part backflow, and part flows into chlorosilane rectifying column, and carries out chlorosilane rectification in chlorosilane rectifying column, and product gas flows into product tower through third tower top discharge pipe, and product gas carries out secondary rectification in product tower, and pure methyl silane is discharged through product discharge pipe, and the methyl silane containing light component impurity is discharged through fourth tower top discharge pipe, and the methyl silane containing heavy component impurity is discharged through fourth tower bottom discharge pipe.

Description

Technical Field

[0001] This invention belongs to the field of silane preparation technology, specifically relating to a production system for preparing silane gas using chlorosilane. Background Technology

[0002] The main methods for preparing silanes include the disproportionation of chlorosilanes, the reduction of magnesium silicides, and the sodium aluminum hydride method.

[0003] The chlorosilane disproportionation process involves reacting industrial silicon powder, silicon tetrachloride, and hydrogen chloride 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, chlorosilane, and silane. The reaction products are a mixture containing silane and various chlorosilanes. High-purity silanes are then separated through a complex purification process. This process is lengthy, involves numerous steps, requires significant equipment investment, and involves large quantities of flammable, explosive, and highly corrosive chemicals (chlorosilanes and hydrogen chloride). Operation is complex and requires extremely high safety standards.

[0004] The magnesium silicide reduction 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, which 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, high pressure), resulting in high consumption of magnesium powder, high production costs, and relatively low product purity.

[0005] The sodium aluminum hydride method involves reacting sodium aluminum hydride with silicon tetrafluoride to synthesize silane gas. The crude silane gas produced by the reaction is then purified to increase its purity to 6N grade silane gas. This method requires a large amount of metallic sodium and aluminum powder, resulting in relatively high costs. Utility Model Content

[0006] This invention addresses the problems of various current methods such as chlorosilane disproportionation, magnesium silicide reduction, and sodium aluminum hydride methods, which suffer from long processes, high investment, high consumption, and low purity. In this invention, chlorosilane is preheated in a first preheater after being fed into a light component removal tower to remove light component impurities. The removed chlorosilane then flows through a first tower bottom outlet pipe, is cooled in a first cooler, and enters an adsorption column for secondary impurity removal. The chlorosilane after secondary impurity removal flows into a reaction tower through a second connecting pipe for reaction. The top liquid from the reaction tower is condensed for a third time in a third condenser, and part of it is refluxed, while part flows into a chlorosilane distillation tower for chlorosilane distillation. The product gas flows into a product tower through a third tower top outlet pipe, where it undergoes secondary distillation. Pure silane is discharged through a product outlet pipe; silane containing light component impurities is discharged through a fourth tower top outlet pipe, and silane containing heavy component impurities is discharged through a fourth tower bottom outlet pipe.

[0007] This utility model is achieved through the following technical solution:

[0008] A production system for preparing silane gas from chlorosilanes includes a light-weight removal tower. The light-weight removal tower is equipped with a chlorosilane feed pipe, a first top outlet pipe, and a first bottom outlet pipe. The first bottom outlet pipe is connected to a first preheater, which is connected to a first connecting pipe. The first connecting pipe is connected to a first cooler, which 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 reaction tower is equipped with a second top outlet pipe and a second bottom outlet pipe. A third condenser is installed on the second top outlet pipe. The condenser is connected to the reaction column via a top reflux pipe. The second top discharge pipe is connected to the chlorosilane distillation column. The chlorosilane distillation column is equipped with a third top discharge pipe and a third bottom discharge pipe. The third bottom discharge pipe is connected to the product column. The product column is equipped with a fourth top discharge pipe, a fourth bottom discharge pipe, a product discharge pipe, and a product column reboiler. The fourth bottom discharge pipe is equipped with a first reboiler reflux pipe and a heavy impurity discharge pipe. The first reboiler reflux pipe is connected to the product column reboiler. The product column reboiler is connected to the product column via a second reboiler reflux pipe.

[0009] Preferably, the reaction tower includes a first separation section, a first reaction section, a second reaction section, and a second separation section arranged sequentially from top to bottom. A first condenser is provided between the first separation section and the first reaction section, and a second condenser is provided between the first reaction section and the second reaction section.

[0010] Preferably, a first tower bottom pressure pump is installed on the first tower bottom discharge pipe.

[0011] Preferably, the product tower reboiler is provided with a heat medium inlet pipe and a heat medium outlet pipe.

[0012] Preferably, the first cooler is connected to the heat medium inlet pipe and the heat medium outlet pipe.

[0013] Preferably, the discharge pipe of the third tower is connected to the second connecting pipe.

[0014] Preferably, a heater is provided on the product discharge pipe.

[0015] Preferably, the discharge pipe of the second tower is connected to the heater, and the heater is provided with an external discharge pipe.

[0016] Preferably, the second tower top discharge pipe is also equipped with a compressor and a second cooler.

[0017] Preferably, a heat medium pressurizing pump is installed on the heat medium outlet pipe, and a second tower bottom pressurizing pump is installed on the second tower bottom outlet pipe.

[0018] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0019] I. The production system for preparing silane gas from chlorosilane provided by this utility model comprises the following steps: chlorosilane is preheated by a first preheater after passing through a chlorosilane feed stream and then enters a light component removal tower to remove light component impurities. The chlorosilane after light component removal flows through a first tower bottom outlet pipe and is cooled by a first cooler before entering an adsorption column for secondary impurity removal. The chlorosilane after secondary impurity removal flows into a reaction tower through a second connecting pipe for reaction. The liquid collected at the top of the reaction tower is partially refluxed after a third condensation by a third condenser, and partially flows into a chlorosilane distillation tower for chlorosilane distillation. The product gas flows into the product tower through a third tower top outlet pipe and undergoes secondary distillation in the product tower. Pure silane is discharged through a product outlet pipe; silane containing light component impurities is discharged through a fourth tower top outlet pipe, and silane containing heavy component impurities is discharged through a fourth tower bottom outlet pipe.

[0020] II. The production system for preparing silane gas from chlorosilane provided by this utility model includes a process where the chlorosilane, after secondary impurity removal, flows between the second reaction section and the second separation section. The chlorosilane undergoes a second reaction in the first and second reaction sections. After the first reaction, it is condensed for the first time in the first condenser and then refluxed back into the reaction tower. After the second reaction, it is condensed for the second time in the second condenser and then refluxed back into the reaction tower. The material in the reaction tower is separated for the first time in the first separation section and then discharged from the bottom of the reaction tower. The material in the reaction tower is separated for the second time in the second separation section and then discharged from the top of the reaction tower. The liquid collected from the top of the reaction tower is condensed for the third time in the third condenser, and part of it is refluxed back into the chlorosilane distillation tower.

[0021] III. The production system for preparing silane gas from chlorosilane provided by this utility model fully utilizes the heat of the material discharged from the bottom of the light-duty removal tower in the first preheater, fully utilizes the cold energy in the heat medium discharge pipe of the product tower reboiler, and fully utilizes the heat of the material discharged from the bottom of the reaction tower, thus making full use of energy.

[0022] IV. The production system for preparing silane gas from chlorosilane provided by this utility model avoids excessively long processes and high equipment investment; makes full use of energy by setting up multiple heat exchangers for cold and hot medium exchange, thus saving energy consumption; and sets up an adsorption column to improve the quality of silane. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of this utility model;

[0024] The components are as follows: 1. Light weight removal tower; 2. Chlorosilane feed pipe; 3. First tower top discharge pipe; 4. First tower bottom discharge pipe; 5. First preheater; 6. First connecting pipe; 7. First cooler; 8. Second connecting pipe; 9. Adsorption column; 10. Third connecting pipe; 11. Reaction tower; 12. Second tower top discharge pipe; 13. Second tower bottom discharge pipe; 14. Third condenser; 15. Tower top reflux pipe; 16. Chlorosilane distillation tower; 17. Third tower top discharge pipe; 18. Third tower bottom discharge pipe; 19. Product tower; 20. Fourth tower top discharge pipe; 21. Fourth tower 21. Discharge pipe of the reactor; 22. Product discharge pipe; 23. Reboiler of the product tower; 24. Reflux pipe of the first reboiler; 25. Heavy impurities discharge pipe; 26. Reflux pipe of the second reboiler; 27. First separation section; 28. First reaction section; 29. ​​Second reaction section; 30. Second separation section; 31. First condenser; 32. Second condenser; 33. First tower reactor pressurization pump; 34. Heater inlet pipe; 35. Heater outlet pipe; 36. Heater; 37. Discharge pipe; 38. Compressor; 39. Second cooler; 40. Heater pressurization pump; 41. Second tower reactor pressurization pump. Detailed Implementation

[0025] 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.

[0026] Example 1

[0027] like Figure 1As shown, a production system for preparing silane gas using chlorosilane includes a light-light gas removal tower 1. The light-light gas removal tower 1 is equipped with a chlorosilane feed pipe 2, a first tower top discharge pipe 3, and a first tower bottom discharge pipe 4. The first tower bottom discharge pipe 4 is connected to a first preheater 5, which is connected to a first connecting pipe 6. The first connecting pipe 6 is connected to a first cooler 7, which is connected to an adsorption column 9 via a second connecting pipe 8. The adsorption column 9 is connected to a reaction tower 11 via a third connecting pipe 10. The reaction tower 11 is equipped with a second tower top discharge pipe 12 and a second tower bottom discharge pipe 13. A third condenser 14 is installed on the second tower top discharge pipe 12. The third condenser 14 is connected to... The top reflux pipe 15 is connected to the reaction column 11, and the second top discharge pipe 12 is connected to the chlorosilane distillation column 16. The chlorosilane distillation column 16 is provided with a third top discharge pipe 17 and a third bottom discharge pipe 18. The third bottom discharge pipe 18 is connected to the product column 19. The product column 19 is provided with a fourth top discharge pipe 20, a fourth bottom discharge pipe 21, a product discharge pipe 22, and a product column reboiler 23. The fourth bottom discharge pipe 21 is provided with a first reboiler reflux pipe 24 and a heavy impurity discharge pipe 25. The first reboiler reflux pipe 24 is connected to the product column reboiler 23. The product column reboiler 23 is connected to the product column 19 through a second reboiler reflux pipe 26.

[0028] Example 2

[0029] like Figure 1 As shown, a production system for preparing silane gas using chlorosilane includes a light-light gas removal tower 1. The light-light gas removal tower 1 is equipped with a chlorosilane feed pipe 2, a first tower top discharge pipe 3, and a first tower bottom discharge pipe 4. The first tower bottom discharge pipe 4 is connected to a first preheater 5, which is connected to a first connecting pipe 6. The first connecting pipe 6 is connected to a first cooler 7, which is connected to an adsorption column 9 via a second connecting pipe 8. The adsorption column 9 is connected to a reaction tower 11 via a third connecting pipe 10. The reaction tower 11 is equipped with a second tower top discharge pipe 12 and a second tower bottom discharge pipe 13. A third condenser 14 is installed on the second tower top discharge pipe 12. The third condenser 14 is connected to... The top reflux pipe 15 is connected to the reaction column 11, and the second top discharge pipe 12 is connected to the chlorosilane distillation column 16. The chlorosilane distillation column 16 is provided with a third top discharge pipe 17 and a third bottom discharge pipe 18. The third bottom discharge pipe 18 is connected to the product column 19. The product column 19 is provided with a fourth top discharge pipe 20, a fourth bottom discharge pipe 21, a product discharge pipe 22, and a product column reboiler 23. The fourth bottom discharge pipe 21 is provided with a first reboiler reflux pipe 24 and a heavy impurity discharge pipe 25. The first reboiler reflux pipe 24 is connected to the product column reboiler 23. The product column reboiler 23 is connected to the product column 19 through a second reboiler reflux pipe 26.

[0030] The reaction tower 11 includes a first separation section 27, a first reaction section 28, a second reaction section 29 and a second separation section 30 arranged sequentially from top to bottom. A first condenser 31 is arranged between the first separation section 27 and the first reaction section 28, and a second condenser 32 is arranged between the first reaction section 28 and the second reaction section 29.

[0031] The first tower bottom discharge pipe 4 is equipped with a first tower bottom pressurization pump 33.

[0032] The product tower reboiler 23 is equipped with a heat medium inlet pipe 34 and a heat medium outlet pipe 35.

[0033] The first cooler 7 is connected to the heat medium inlet pipe 34 and the heat medium outlet pipe 35.

[0034] The third tower bottom discharge pipe 18 is connected to the second connecting pipe 8.

[0035] A heater 36 is provided on the product discharge pipe 22.

[0036] The second tower bottom discharge pipe 13 is connected to the heater 36, and the heater 36 is provided with an external discharge pipe 37.

[0037] The second tower top discharge pipe 12 is also equipped with a compressor 38 and a second cooler 39.

[0038] The heat medium outlet pipe 35 is equipped with a heat medium pressurizing pump 40, and the second tower bottom outlet pipe 13 is equipped with a second tower bottom pressurizing pump 41.

[0039] Among them, the light component removal tower 1, the first preheater 5, the first cooler 7, the adsorption column 9, the third condenser 14, the chlorosilane distillation tower 16, the product tower 19, the product tower reboiler 23, the first separation section 27, the first reaction section 28, the second reaction section 29, the second separation section 30, the first condenser 31, the second condenser 32, the first tower bottom pressurization pump 33, the heater 36, the compressor 38, the second cooler 39, the heat medium pressurization pump 40, and the second tower bottom pressurization pump 41 are all existing technologies and will not be described in detail here.

[0040] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0041] I. The production system for preparing silane gas using chlorosilane provided by this utility model involves chlorosilane being preheated by a first preheater 5 and then entering a light component removal tower 1 to remove light component impurities. The chlorosilane after light component removal flows through a first tower bottom outlet pipe 4 and is cooled by a first cooler 7 before entering an adsorption column 9 for secondary impurity removal. The chlorosilane after secondary impurity removal flows into a reaction tower 11 through a second connecting pipe 8 for reaction. The liquid collected from the top of the reaction tower 11 is partially refluxed after a third condensation by a third condenser 14, and partially flows into a chlorosilane distillation tower 16 for chlorosilane distillation. The product gas flows into a product tower 19 through a third tower top outlet pipe 17. The product gas undergoes secondary distillation in the product tower 19, and the pure silane is discharged through a product outlet pipe 22. The silane containing light component impurities is discharged through a fourth tower top outlet pipe 20, and the silane containing heavy component impurities is discharged through a fourth tower bottom outlet pipe 21.

[0042] II. The production system for preparing silane gas from chlorosilane provided by this utility model: After secondary impurity removal, the chlorosilane flows into the space between the second reaction section 29 and the second separation section 30. The chlorosilane undergoes a second reaction through the first reaction section 28 and the second reaction section 29. After the first reaction, it is condensed for the first time through the first condenser 31 and then returned to the reaction tower 11. After the second reaction, it is condensed for the second time through the second condenser 32 and then returned to the reaction tower 11. The material in the reaction tower 11 is separated for the first time through the first separation section 27 and then discharged from the bottom of the reaction tower 11. The material in the reaction tower 11 is separated for the second time through the second separation section 30 and then discharged from the top of the reaction tower 11. The liquid collected from the top of the reaction tower 11 is partially refluxed and partially flows into the chlorosilane distillation tower 16 after being condensed for the third time through the third condenser 14.

[0043] III. The production system for preparing silane gas using chlorosilane provided by this utility model fully utilizes the heat of the material collected from the bottom of the light-duty removal tower 1 in the first preheater 5, fully utilizes the cold energy in the heat medium discharge pipe of the product tower reboiler 23, and fully utilizes the heat of the material collected from the bottom of the reaction tower 11, thus making full use of energy.

[0044] IV. The production system for preparing silane gas from chlorosilane provided by this utility model avoids excessively long processes and high equipment investment; makes full use of energy by setting up multiple heat exchangers for cold and hot medium exchange, thus saving energy consumption; and sets up an adsorption column 9 to improve the quality of silane.

[0045] 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 chlorosilanes, characterized in that: The system includes a light silane removal tower (1), which is equipped with a chlorosilane feed pipe (2), a first tower top discharge pipe (3), and a first tower bottom discharge pipe (4). The first tower bottom discharge pipe (4) is connected to a first preheater (5), which is connected to a first connecting pipe (6). The first connecting pipe (6) is connected to a first cooler (7), which is connected to an adsorption column (9) via a second connecting pipe (8). The adsorption column (9) is connected to a reaction tower (11) via a third connecting pipe (10). The reaction tower (11) is equipped with a second tower top discharge pipe (12) and a second tower bottom discharge pipe (13). The second tower top discharge pipe (12) is equipped with a third condenser (14), which is connected to a tower top reflux pipe (15). The second column top discharge pipe (12) is connected to the chlorosilane distillation column (16). The chlorosilane distillation column (16) is provided with a third column top discharge pipe (17) and a third column bottom discharge pipe (18). The third column bottom discharge pipe (18) is connected to the product column (19). The product column (19) is provided with a fourth column top discharge pipe (20), a fourth column bottom discharge pipe (21), a product discharge pipe (22), and a product column reboiler (23). The fourth column bottom discharge pipe (21) is provided with a first reboiler reflux pipe (24) and a heavy impurity discharge pipe (25). The first reboiler reflux pipe (24) is connected to the product column reboiler (23). The product column reboiler (23) is connected to the product column (19) through a second reboiler reflux pipe (26).

2. The production system for preparing silane gas from chlorosilane according to claim 1, characterized in that: The reaction tower (11) includes a first separation section (27), a first reaction section (28), a second reaction section (29) and a second separation section (30) arranged sequentially from top to bottom. A first condenser (31) is arranged between the first separation section (27) and the first reaction section (28), and a second condenser (32) is arranged between the first reaction section (28) and the second reaction section (29).

3. The production system for preparing silane gas using chlorosilane according to claim 2, characterized in that: The first tower bottom discharge pipe (4) is equipped with a first tower bottom pressure pump (33).

4. The production system for preparing silane gas from chlorosilane according to claim 3, characterized in that: The product tower reboiler (23) is equipped with a heat medium inlet pipe (34) and a heat medium outlet pipe (35).

5. The production system for preparing silane gas from chlorosilane according to claim 4, characterized in that: The first cooler (7) is connected to the heat medium inlet pipe (34) and the heat medium outlet pipe (35).

6. The production system for preparing silane gas from chlorosilane according to claim 5, characterized in that: The third tower bottom discharge pipe (18) is connected to the second connecting pipe (8).

7. The production system for preparing silane gas from chlorosilane according to claim 6, characterized in that: A heater (36) is provided on the product discharge pipe (22).

8. The production system for preparing silane gas from chlorosilane according to claim 7, characterized in that: The second tower bottom discharge pipe (13) is connected to the heater (36), and the heater (36) is provided with an external discharge pipe (37).

9. The production system for preparing silane gas from chlorosilane according to claim 8, characterized in that: A compressor (38) and a second cooler (39) are also installed on the second tower top discharge pipe (12).

10. The production system for preparing silane gas from chlorosilane according to claim 9, characterized in that: A heat medium pressurizing pump (40) is installed on the heat medium outlet pipe (35), and a second tower bottom pressurizing pump (41) is installed on the second tower bottom outlet pipe (13).

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