Impurity removal system for preparing disproportionation reaction silane gas

Abstract

The utility model provides an impurity removal system for preparing disproportionation reaction silane gas, which comprises a dehydrogenation tower (1) for preparing silane, and further comprises a side production pipeline (5) arranged in the middle of the side of the dehydrogenation tower (1), the other end of the side production pipeline (5) is in fluid connection with a circulating water condenser (6), and the other end of the circulating water condenser (6) is in fluid connection with the dehydrogenation tower (1). A liquid phase outlet of the circulating water condenser (6) is in fluid connection with a buffer tank (7), and the buffer tank (7) is in fluid connection with a silane reaction tower (9) through a pump (8). According to the device, the content of heavy phosphorus impurities in silane gas can be reduced, and the quality of the product silane gas is improved; the dehydrogenation tower is transformed to reduce the influence of phosphorus impurities on the activity of the catalyst in the reaction tower.

Description

Technical Field

[0001] This utility model relates to a purification system, and more particularly to a purification system for the preparation of silane gas by disproportionation reaction. Background Technology

[0002] This section provides only background information relevant to this disclosure and is not necessarily prior art.

[0003] Currently, in the disproportionation reaction of silane gas, phosphorus (P) impurities in the feedstock cannot be completely removed during the dehydrogenation tower, resulting in some phosphorus impurities remaining in the silane gas product and affecting its quality. The current method involves phosphorus removal at the source stage, but the treated chlorosilane still contains some phosphorus. Furthermore, the current phosphorus removal process in silane gas preparation relies on catalyst adsorption in the reaction tower, where the catalyst adsorbs some phosphorus, and on increasing the effluent flow rate in a downstream process to remove phosphorus from the silane gas product.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0005] Purpose of the invention: The technical problem to be solved by this invention is to provide a purification system for the preparation of silane gas by disproportionation reaction, which addresses the shortcomings of the existing technology.

[0006] To address the aforementioned technical problems, this utility model discloses a purification system for the preparation of silane gas from a disproportionation reaction, comprising a dehydrogenation tower for silane preparation, and the system further comprising:

[0007] A side-extraction pipeline is installed in the middle of the side of the dehydrogenation tower. The other end of the side-extraction pipeline is fluidly connected to a circulating water condenser. The liquid phase outlet of the circulating water condenser is fluidly connected to a buffer tank. The buffer tank is fluidly connected to the silane reaction tower through a pump.

[0008] Furthermore, the bottom outlet of the dehydrogenation tower is fluidly connected to the filtration and storage device, and the outlet of the filtration and storage device is fluidly connected to the middle inlet of the dehydrogenation tower.

[0009] Furthermore, the filter storage device includes:

[0010] The raw material tank is fluidly connected to the bottom outlet of the dehydrogenation tower, and the raw material tank is fluidly connected to the product tank through an adsorption column. The outlet of the product tank is fluidly connected to the middle inlet of the dehydrogenation tower.

[0011] Furthermore, the adsorption column is provided with a catalytic adsorption substance to reduce impurities in trichlorosilane.

[0012] Furthermore, the number of adsorption columns is set to multiple.

[0013] Furthermore, the adsorption columns are in a parallel structure.

[0014] Furthermore, in the parallel structure, each adsorption column is equipped with an independent valve upstream.

[0015] Furthermore, the top outlet of the dehydrogenation tower is fluidly connected to a downstream tail gas condensation system for treating gaseous substances within the dehydrogenation tower.

[0016] Furthermore, the gas phase outlet of the circulating water condenser is fluidly connected to the exhaust gas condensation system.

[0017] Furthermore, the side sampling pipeline is located at the point where gaseous substances accumulate in the middle of the vessel of the dehydrogenation tower.

[0018] Beneficial effects:

[0019] 1. This utility model can reduce the content of phosphorus impurities in silane gas and improve the quality of silane gas products.

[0020] 2. This utility model reduces the impact of phosphorus impurities on catalyst activity in the reaction tower by modifying the dehydrogenation tower. Attached Figure Description

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, and the advantages of the present invention in the above and / or other aspects will become clearer.

[0022] Figure 1 This is a schematic diagram of the overall architecture of this utility model.

[0023] In the diagram, 1 is the dehydrogenation tower, 2 is the raw material tank, 3 is the adsorption column, 4 is the product tank, 5 is the side-collection pipeline, 6 is the circulating water condenser, 7 is the buffer tank, 8 is the pump, and 9 is the silane reaction tower. Detailed Implementation

[0024] The overall concept of this invention is as follows: In the preparation of silane gas, by modifying the dehydrogenation tower, reducing the entry of phosphorus impurities into the reaction system, and adding heat exchangers, reflux tanks, pumps and corresponding pipelines, the product quality will be greatly improved, ensuring the control of phosphorus impurities in the silane gas product and reducing the impact of phosphorus impurities on catalyst activity.

[0025] Specifically, a side sampling line is added to the dehydrogenation tower, allowing the material inside the condenser side sampling line to enter the reaction tower, thereby reducing the amount of phosphorus impurities entering the reaction tower and thus affecting product quality, as well as reducing the impact of phosphorus impurities on the catalyst in the reaction tower.

[0026] The dehydrogenation tower 1 for silane gas preparation was modified. The TCS (trichlorosilane) in the bottom of dehydrogenation tower 1 contained a significant amount of phosphorus impurities. The TCS discharged to the upstream phosphorus removal system's feed tank 2 underwent phosphorus impurity removal via adsorption column 3 and was then fed into product tank 4. The TCS in product tank 4 entered dehydrogenation tower 1 as feedstock for silane gas preparation. By adding a side-collection pipeline 5 to dehydrogenation tower 1, the less phosphorus-containing gaseous TCS was promptly collected, condensed by circulating water condenser 6, and then fed into buffer tank 7. Finally, pump 8 transported the condensate to the silane reaction tower 9. The hydrogen component at the top of dehydrogenation tower 1 was treated by a tail gas condensation system (not shown).

[0027] like Figure 1 As shown, a purification system for the preparation of silane gas via disproportionation reaction includes:

[0028] The dehydrogenation tower 1 is used for silane preparation. The bottom outlet of the dehydrogenation tower 1 is fluidly connected to the raw material tank 2 to transport trichlorosilane in the bottom of the dehydrogenation tower 1.

[0029] Raw material tank 2 is fluidly connected to product tank 4 via adsorption column 3. Adsorption column 3 is used to remove phosphorus impurities. Under the action of the catalyst in adsorption column 3, boron and phosphorus impurities in trichlorosilane are adsorbed onto adsorption column 3, thus reducing the amount of boron and phosphorus impurities in trichlorosilane passing through adsorption column 3. Adsorption column 3 can be configured as multiple parallel lines as needed to improve efficiency. Each of the multiple parallel adsorption columns 3 is equipped with a valve upstream for individually closing the passage of adsorption column 3 for maintenance.

[0030] Product tank 4 is fluidly connected to dehydrogenation tower 1, and the processed trichlorosilane is fed into dehydrogenation tower 1 for further reaction.

[0031] The top of the dehydrogenation tower 1 is fluidly connected to the tail gas condensation system (not shown) for treating gaseous substances such as hydrogen components in the dehydrogenation tower 1.

[0032] The dehydrogenation tower 1 is equipped with a side sampling pipeline 5, which is fluidly connected to the circulating water condenser 6 to extract and condense the gaseous TCS with low phosphorus content.

[0033] The gas phase outlet of the circulating water condenser 6 is fluidly connected to the tail gas condensation system (not shown), and the liquid phase outlet is fluidly connected to the buffer tank 7.

[0034] The buffer tank 7 is fluidly connected to the silane reaction tower 9 via the pump 8, and is used to transfer the condensed material stored in the buffer tank 7 to the silane reaction tower 9 for subsequent reaction.

[0035] This invention provides a concept and method for a purification system in the preparation of silane gas from a disproportionation reaction. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of this invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technology.

Claims

1. A purification system for the preparation of silane gas from a disproportionation reaction, comprising a dehydrogenation tower (1) for silane preparation, characterized in that, The system also includes: A side-extraction pipeline (5) is opened in the middle of the side of the dehydrogenation tower (1). The other end of the side-extraction pipeline (5) is fluidly connected to the circulating water condenser (6). The liquid phase outlet of the circulating water condenser (6) is fluidly connected to the buffer tank (7). The buffer tank (7) is fluidly connected to the silane reaction tower (9) through a pump (8).

2. The impurity removal system for the preparation of silane gas from a disproportionation reaction according to claim 1, characterized in that, The bottom outlet of the dehydrogenation tower (1) is fluidly connected to the filter and storage device, and the outlet of the filter and storage device is fluidly connected to the middle inlet of the dehydrogenation tower (1).

3. The impurity removal system for the preparation of silane gas from a disproportionation reaction according to claim 2, characterized in that, The filter storage device includes: A raw material tank (2) is fluidly connected to the bottom outlet of the dehydrogenation tower (1). The raw material tank (2) is fluidly connected to the product tank (4) through an adsorption column (3). The outlet of the product tank (4) is fluidly connected to the middle inlet of the dehydrogenation tower (1).

4. The impurity removal system for the preparation of silane gas from a disproportionation reaction according to claim 3, characterized in that, The adsorption column (3) is provided with a catalytic adsorption substance to reduce impurities in trichlorosilane.

5. The impurity removal system for the preparation of silane gas from a disproportionation reaction according to claim 4, characterized in that, The number of adsorption columns (3) is set to multiple.

6. The impurity removal system for the preparation of silane gas from a disproportionation reaction according to claim 5, characterized in that, The adsorption column (3) has a parallel structure.

7. The impurity removal system for the preparation of silane gas from a disproportionation reaction according to claim 6, characterized in that, In the parallel structure, each of the adsorption columns (3) is provided with an independent valve upstream.

8. The impurity removal system for the preparation of silane gas from a disproportionation reaction according to claim 7, characterized in that, The top outlet of the dehydrogenation tower (1) is fluidly connected to the downstream tail gas condensation system for processing gaseous substances in the dehydrogenation tower (1).

9. The impurity removal system for the preparation of silane gas from a disproportionation reaction according to claim 8, characterized in that, The gas phase outlet of the circulating water condenser (6) is fluidly connected to the tail gas condensation system.

10. A purification system for the preparation of silane gas from a disproportionation reaction according to claim 9, characterized in that, The side-collection pipeline (5) is located at the gas phase accumulation point in the middle of the vessel of the dehydrogenation tower (1).

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