Device for separating trichlorosilane tail gas and co-producing fumed silica

Abstract

The utility model relates to the technical field of chemical gas recovery, and provides a device for separating trichlorosilane tail gas and co-producing fumed silica, which adopts a combined process to treat the trichlorosilane tail gas and is provided with a rectification separation seat provided with a low-temperature cold energy recovery mechanism. Hydrogen, hydrogen chloride and chlorosilane in the tail gas are separated step by step through the rectification separation assembly, the hydrogen chloride and the chlorosilane are directly conveyed to the combustion assembly, the purity of the hydrogen chloride is recycled to the trichlorosilane tail gas treatment assembly, recycling after separation is achieved, and the purposes of further saving energy consumption and improving the purity are achieved; a fumed silica combustion furnace suitable for low-boiling-point chlorosilane is adopted, so that the chlorosilane and hydrogen are mixed and combusted to generate fumed silica and hydrogen chloride, and the fumed silica can be directly discharged through a fumed silica discharge pipe; and the generated hydrogen chloride is recovered into the trichlorosilane tail gas treatment seat through a second hydrogen chloride return pipe, and closed-loop utilization is realized.

Description

A device for separating trichlorosilane tail gas and producing fumed silica. Technical Field

[0001] This utility model relates to the field of chemical gas recovery technology, specifically to a device for separating trichlorosilane tail gas and producing gaseous silica. Background Technology

[0002] The main purpose of trichlorosilane tail gas separation is to recover valuable components such as trichlorosilane, silicon tetrachloride, hydrogen chloride, and hydrogen from the tail gas. These components have important applications in chemical production. Through separation and purification, resources can be reused, improving production efficiency. Specifically, trichlorosilane and silicon tetrachloride are key raw materials for synthesizing organosilicon materials. Tail gas separation technology can efficiently recover these components from the tail gas, reducing raw material waste. Meanwhile, hydrogen chloride and hydrogen are also important chemical raw materials. After recovery, they can be used to synthesize other chemicals, further broadening the application scope of the resources. In addition, trichlorosilane tail gas separation also helps reduce environmental pollution. If harmful substances in the tail gas are directly emitted into the atmosphere, they will pollute the environment. Through separation technology, these harmful substances can be converted into reusable resources, achieving environmentally friendly production. In conclusion, trichlorosilane tail gas separation is of great significance for improving resource utilization efficiency and reducing environmental pollution. With continuous technological progress and innovation, tail gas separation technology will play an increasingly important role in chemical production.

[0003] A search revealed that CN220026553U discloses a pressure swing adsorption (PSA) recovery system for trichlorosilane synthesis tail gas. This system uses two adsorption units to adsorb and regenerate hydrogen chloride / chlorosilane and nitrogen / hydrogen, respectively, yielding high-purity hydrogen at the tail gas level. Each adsorption unit includes at least two adsorption towers to achieve pressure equalization between the towers. A vacuum pump provides power for desorption, resulting in low energy consumption. Furthermore, the system enables the recovery and utilization of the two mixed gases and high-purity hydrogen, thereby increasing the economic value of the recovered tail gas byproducts.

[0004] Although the aforementioned trichlorosilane synthesis tail gas pressure swing adsorption recovery system proposes a two-stage pressure swing adsorption system for separating hydrogen chloride / chlorosilane and hydrogen, it suffers from problems such as low adsorbent redundancy, complex equipment, high energy consumption, and inability to directly co-produce high value-added products. Summary of the Invention

[0005] This invention proposes a device for separating trichlorosilane tail gas and co-producing gaseous silica, which solves the problems of low adsorbent redundancy, complex equipment, high energy consumption, and inability to directly co-produce high value-added products in the treatment of trichlorosilane synthesis tail gas in the prior art.

[0006] The technical solution of this utility model is as follows: A trichlorosilane tail gas separation and parallel production of gaseous silica device, comprising a distillation separation component, a trichlorosilane tail gas treatment component that can be fed into the trichlorosilane tail gas is provided on one side of the distillation separation component, and a combustion component that can receive chlorosilane and hydrogen produced after low-temperature distillation is provided on the other side of the distillation separation component. The combustion component includes a combustion furnace body with a furnace cavity inside. The combustion component also includes a second hydrogen chloride return pipe that can send the hydrogen chloride produced after combustion back into the trichlorosilane tail gas treatment component. The second hydrogen chloride return pipe is fixedly connected to the top of the combustion furnace body.

[0007] Preferably, the trichlorosilane tail gas treatment assembly includes a trichlorosilane tail gas treatment seat, which is located outside the distillation separation assembly. The trichlorosilane tail gas treatment seat also has a treatment chamber inside, and the top of the treatment chamber is connected to the second hydrogen chloride return pipe.

[0008] Preferably, the trichlorosilane tail gas treatment assembly further includes a tail gas inlet pipe, which is fixedly connected to the outside of the trichlorosilane tail gas treatment base and is connected to the treatment chamber.

[0009] Preferably, the distillation separation assembly includes a distillation separation seat, and the distillation separation seat has a separation chamber inside.

[0010] Preferably, the trichlorosilane tail gas treatment assembly further includes a tail gas outlet pipe, one end of which is connected to the treatment chamber and the other end of which is connected to the separation chamber.

[0011] Preferably, the distillation separation assembly further includes a low-temperature cold energy recovery mechanism, which is fixedly installed inside and outside the distillation separation seat. The distillation separation assembly also includes a first hydrogen chloride return pipe, one end of which is connected to the separation chamber and the other end of which is connected to the processing chamber.

[0012] Preferably, the combustion assembly further includes a fuel filling chamber and an ignition mechanism, the fuel filling chamber and the ignition mechanism being fixedly installed at the bottom of the furnace cavity, and the combustion assembly further includes a fumed silica discharge pipe, the fumed silica discharge pipe being fixedly connected to the side of the furnace cavity.

[0013] Preferably, the distillation separation assembly further includes an inlet pipe, one end of which is connected to the separation chamber and the other end of which is connected to the furnace chamber.

[0014] The beneficial effects of this utility model are as follows:

[0015] 1. This utility model adopts a combined process to treat trichlorosilane tail gas and is equipped with a distillation separation unit with a low-temperature cold energy recovery mechanism. The hydrogen, hydrogen chloride, and chlorosilane in the tail gas are separated in stages through the distillation separation component. The hydrogen with a purity of ≥99.99% and the chlorosilane are directly transported to the combustion component, while the hydrogen chloride with a purity of ≥99.5% is recycled to the trichlorosilane tail gas treatment component, realizing "separation and reuse", thereby further saving energy and improving purity.

[0016] 2. This utility model uses a gas phase silica combustion furnace suitable for low-boiling-point chlorosilanes to mix and burn chlorosilanes with hydrogen to generate gas phase silica and hydrogen chloride. The gas phase silica can be directly discharged through the gas phase silica discharge pipe, while the generated hydrogen chloride is recovered to the trichlorosilane tail gas treatment base through the second hydrogen chloride return pipe and realized closed-loop utilization. Attached Figure Description

[0017] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0018] Figure 1 is a schematic diagram of the overall device of this utility model;

[0019] Figure 2 is a schematic diagram of the internal structure of the overall device of this utility model;

[0020] Figure 3 is an enlarged view of region A in Figure 2;

[0021] Figure 4 is an enlarged view of region B in Figure 2;

[0022] In the diagram: 1. Trichlorosilane tail gas treatment assembly; 11. Trichlorosilane tail gas treatment seat; 111. Treatment chamber; 12. Tail gas inlet pipe; 13. Tail gas outlet pipe; 2. Distillation and separation assembly; 21. Distillation and separation seat; 211. Separation chamber; 22. Low-temperature cold energy recovery mechanism; 23. First hydrogen chloride return pipe; 24. Feed pipe; 3. Combustion assembly; 31. Combustion furnace body; 311. Furnace chamber; 32. Fuel filling chamber; 33. Ignition mechanism; 34. Second hydrogen chloride return pipe; 35. Gas phase silica discharge pipe. Detailed Implementation

[0023] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this utility model.

[0024] Please refer to Figures 1, 2, 3, and 4. This utility model provides a technical solution: a trichlorosilane tail gas separation and parallel production of gaseous silica device, including a distillation separation component 2. A trichlorosilane tail gas treatment component 1 is provided on one side of the distillation separation component 2, which can be fed into the trichlorosilane tail gas. A combustion component 3 is provided on the other side of the distillation separation component 2, which can receive chlorosilane and hydrogen produced after low-temperature distillation. The combustion component 3 includes a combustion furnace body 31, and a furnace cavity 311 is opened inside the combustion furnace body 31. The combustion component 3 also includes a second hydrogen chloride return pipe 34, which can send the hydrogen chloride produced after combustion back into the trichlorosilane tail gas treatment component 1. The second hydrogen chloride return pipe 34 is fixedly connected to the top of the combustion furnace body 31.

[0025] This design solves the problems of low adsorbent redundancy, complex equipment, high energy consumption, and inability to directly co-produce high value-added products in the treatment of trichlorosilane synthesis tail gas in existing technologies.

[0026] Please refer to Figures 1, 2, 3 and 4. The trichlorosilane tail gas treatment assembly 1 includes a trichlorosilane tail gas treatment seat 11, which is located outside the distillation and separation assembly 2. The trichlorosilane tail gas treatment seat 11 also has a treatment chamber 111 inside, and the top of the treatment chamber 111 is connected to the second hydrogen chloride return pipe 34.

[0027] The trichlorosilane tail gas treatment assembly 1 also includes a tail gas inlet pipe 12, which is fixedly connected to the outside of the trichlorosilane tail gas treatment base 11 and is connected to the treatment chamber 111.

[0028] The distillation separation assembly 2 includes a distillation separation seat 21, and a separation chamber 211 is provided inside the distillation separation seat 21.

[0029] The trichlorosilane tail gas treatment assembly 1 also includes a tail gas outlet pipe 13, one end of which is connected to the treatment chamber 111, and the other end of which is connected to the separation chamber 211.

[0030] The distillation separation assembly 2 also includes a low-temperature cold energy recovery mechanism 22, which is fixedly installed inside and outside the distillation separation seat 21. The distillation separation assembly 2 also includes a first hydrogen chloride return pipe 23, one end of which is connected to the separation chamber 211 and the other end of which is connected to the processing chamber 111.

[0031] The combustion assembly 3 also includes a fuel filling chamber 32 and an ignition mechanism 33. The fuel filling chamber 32 and the ignition mechanism 33 are fixedly installed at the bottom of the furnace cavity 311. The combustion assembly 3 also includes a fumed silica discharge pipe 35, which is fixedly connected to the side of the furnace cavity 311.

[0032] The distillation separation assembly 2 also includes an inlet pipe 24, one end of which is connected to the separation chamber 211 and the other end of which is connected to the furnace chamber 311.

[0033] This design separates hydrogen, hydrogen chloride, and chlorosilane in the tail gas through a distillation separation component 2. The hydrogen with a purity of ≥99.99% and the chlorosilane are directly transported to the combustion component 3, while the hydrogen chloride with a purity of ≥99.5% is recycled to the trichlorosilane tail gas treatment component 1, achieving "separation and reuse".

[0034] The separated chlorosilane and hydrogen are directly reacted in the trichlorosilane tail gas treatment component 1 to generate gaseous silicon dioxide, eliminating the need for additional storage or transportation of intermediate products and reducing the risk of material loss.

[0035] This design uses a distillation separation seat 21 integrated with a low-temperature cold energy recovery mechanism 22 to separate low-boiling hydrogen, medium-boiling hydrogen chloride, and high-boiling chlorosilane through gradient cooling from -50℃ to 20℃.

[0036] Combustion component 3 design: Chlorosilane is mixed with hydrogen and combusted to produce gaseous silicon dioxide and hydrogen chloride;

[0037] The hydrogen chloride produced by combustion is returned to the trichlorosilane tail gas treatment unit 11, achieving closed-loop utilization.

[0038] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A device for separating trichlorosilane tail gas and producing fumed silica, comprising a distillation separation component (2), characterized in that, The distillation separation component (2) is provided with a trichlorosilane tail gas treatment component (1) on one side, which can be fed into the trichlorosilane tail gas. The distillation separation component (2) is provided with a combustion component (3) on the other side, which can receive the chlorosilane and hydrogen produced after low-temperature distillation. The combustion component (3) includes a combustion furnace body (31), and a furnace cavity (311) is opened inside the combustion furnace body (31). The combustion component (3) also includes a second hydrogen chloride return pipe (34) that can send the hydrogen chloride produced after combustion back into the trichlorosilane tail gas treatment component (1). The second hydrogen chloride return pipe (34) is fixedly connected to the top of the combustion furnace body (31).

2. The device for separating and producing fumed silica from trichlorosilane tail gas according to claim 1, characterized in that, The trichlorosilane tail gas treatment assembly (1) includes a trichlorosilane tail gas treatment seat (11), which is located outside the distillation separation assembly (2). The trichlorosilane tail gas treatment seat (11) also has a treatment chamber (111) inside, and the top of the treatment chamber (111) is connected to the second hydrogen chloride return pipe (34).

3. A device for separating and producing fumed silica from trichlorosilane tail gas according to claim 2, characterized in that, The trichlorosilane tail gas treatment assembly (1) further includes a tail gas inlet pipe (12), which is fixedly connected to the outside of the trichlorosilane tail gas treatment base (11) and is connected to the treatment chamber (111).

4. The trichlorosilane tail gas separation and parallel production of fumed silica device according to claim 2, characterized in that, The distillation separation assembly (2) includes a distillation separation seat (21), and a separation chamber (211) is provided inside the distillation separation seat (21).

5. The apparatus for separating and producing fumed silica from trichlorosilane off-gas according to claim 2, wherein, The trichlorosilane tail gas treatment assembly (1) further includes a tail gas outlet pipe (13), one end of which is connected to the treatment chamber (111), and the other end of which is connected to the separation chamber (211).

6. A device for separating and producing fumed silica from trichlorosilane off-gas according to claim 4, characterized in that, The distillation separation assembly (2) also includes a low-temperature cold energy recovery mechanism (22), which is fixedly installed inside and outside the distillation separation seat (21). The distillation separation assembly (2) also includes a first hydrogen chloride return pipe (23), one end of which is connected to the separation chamber (211), and the other end of which is connected to the processing chamber (111).

7. The device according to claim 1, wherein The combustion assembly (3) also includes a fuel filling chamber (32) and an ignition mechanism (33), which are fixedly installed at the bottom of the furnace cavity (311). The combustion assembly (3) also includes a fumed silica discharge pipe (35), which is fixedly connected to the side of the furnace cavity (311).

8. The apparatus according to claim 4, wherein the apparatus is characterized by: The distillation separation assembly (2) also includes an inlet pipe (24), one end of which is connected to the separation chamber (211) and the other end of which is connected to the furnace chamber (311).

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