A high-oxygen hydrogen-rich tail gas purification device for sodium chlorate

Abstract

The utility model discloses a kind of high-oxygen hydrogen-rich tail gas purification equipment for sodium chlorate, including tail gas pipeline and the Roots blower connected with tail gas pipeline, Roots blower outlet end is connected with dechlorinator, dechlorinator outlet end is sequentially connected with first deoxygenator and second deoxygenator, first deoxygenator and second deoxygenator are connected with first cooling blow line and second cooling blow line respectively, second deoxygenator outlet end is sequentially connected with first cooler and dryer, and dryer is connected with PSA system, and PSA system is connected with discharge pipeline.The utility model can carry out multistage purification to the oxygen with higher content in sodium chlorate tail gas, improve the purity of hydrogen after tail gas purification, cooling can be carried out to the deoxidation process in first deoxygenator and second deoxygenator respectively, reduce the risk caused by heat generated in deoxidation process to deoxidation process, guarantee the security of tail gas purification.

Description

Technical Field

[0001] This utility model relates to the technical field of exhaust gas purification equipment, and in particular to a high-oxygen, hydrogen-rich exhaust gas purification device for sodium chlorate. Background Technology

[0002] High-purity hydrogen is an important type of industrial gas, widely used in chemical, petrochemical, petroleum, energy, electronics, metallurgy, food, machinery, aerospace, and nuclear industries. With the continuous development of hydrogen energy in my country, the demand for hydrogen for fuel cells and high-purity hydrogen is constantly increasing, making hydrogen energy a crucial component of China's energy system. Currently, my country's hydrogen sources mainly consist of fossil fuel-derived hydrogen, water electrolysis, and chlor-alkali tail gas. Among these, chlor-alkali tail gas, as an industrial byproduct, has low raw material costs, large quantities, and relatively good environmental performance. The annual hydrogen production from the chlor-alkali industry is 700,000 to 800,000 tons. Purifying the pre-purified chlor-alkali tail gas into high-purity hydrogen to meet my country's growing hydrogen energy demand has broad market prospects.

[0003] Conventional methods for purifying chlor-alkali tail gas to obtain high-purity hydrogen include palladium membrane diffusion, pressure swing adsorption (PSA), and low-temperature adsorption. For example, patent publication CN215208468U discloses a hydrogen purification system for chlor-alkali tail gas, which can effectively improve the recovery rate of hydrogen during the purification process. However, for sodium chlorate tail gas, a common component of chlor-alkali tail gas, both oxygen and hydrogen content are high. When using existing methods to purify this tail gas, the purity of the purified hydrogen is insufficient. Furthermore, under such high oxygen content conditions, existing compressors apply excessive pressure to the tail gas during deoxygenation. Additionally, the deoxygenation process is exothermic, posing certain risks during the process. Utility Model Content

[0004] To address the technical problems of existing technologies, such as the high oxygen and hydrogen content in sodium chlorate tail gas, insufficient hydrogen purity after tail gas purification, and certain risks during the deoxygenation process, this utility model provides the following technical solution.

[0005] This utility model discloses a high-oxygen, hydrogen-rich tail gas purification device for sodium chlorate, comprising a tail gas pipeline and a Roots blower connected to the tail gas pipeline. A dechlorinator is connected to the outlet end of the Roots blower, and a first deoxygenator and a second deoxygenator are sequentially connected to the outlet end of the dechlorinator. The first deoxygenator and the second deoxygenator are respectively connected to a first cooling pipeline and a second cooling pipeline. A first cooler and a dryer are sequentially connected to the outlet end of the second deoxygenator. The dryer is connected to a PSA system, and the PSA system is connected to a discharge pipeline.

[0006] As a further technical solution, the discharge pipeline is connected to a return gas pipeline, the return gas pipeline is connected to a second cooler and an exhaust fan, and the exhaust fan is connected to the first cooling pipeline and the second cooling pipeline respectively.

[0007] As a further technical solution, the return gas pipeline, the first cooling pipeline, and the second cooling pipeline are all equipped with one-way shut-off valves.

[0008] As a further technical solution, the first cooling pipeline and the second cooling pipeline are respectively connected to external high-purity hydrogen gas.

[0009] As a further technical solution, a compressor is connected between the dryer and the PSA system.

[0010] As a further technical solution, the Roots blower is an oil-free lubricated Roots blower.

[0011] The beneficial effects of this invention are that the dechlorinator is sequentially connected to a first deoxygenator and a second deoxygenator, enabling multi-stage purification of the high oxygen content in sodium chlorate tail gas, thereby improving the purity of the hydrogen after purification. Simultaneously, the first and second deoxygenators are respectively connected to a first cooling pipeline and a second cooling pipeline, which can respectively cool the deoxygenation process in the first and second deoxygenators, reducing the risk posed by the heat generated during deoxygenation and ensuring the safety of tail gas purification. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of the high-oxygen, hydrogen-rich tail gas purification equipment for sodium chlorate according to this utility model;

[0013] In the diagram: 1-Exhaust gas pipeline; 2-Roots blower; 3-Dechlorinator; 4-First deoxygenator; 5-Second deoxygenator; 6-First cooler; 7-Dryer; 8-Compressor; 9-PSA system; 10-Discharge pipeline; 11-Return gas pipeline; 12-Second cooler; 13-Exhaust fan; 14-First cooling pipeline; 15-Second cooling pipeline. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0015] In the description of this utility model, it should be understood that the terms "upper" and "lower" are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0016] like Figure 1 As shown, this utility model discloses a high-oxygen, hydrogen-rich tail gas purification device for sodium chlorate, including a tail gas pipeline 1 and a Roots blower 2 connected to the tail gas pipeline 1. The tail gas pipeline 1 is used to transport sodium chlorate tail gas, and the Roots blower 2 is used to transport the tail gas in a metered manner. The Roots blower 2 adopts an oil-free lubricated Roots blower to prevent the introduction of foreign impurities into the sodium chlorate tail gas.

[0017] In a preferred embodiment, a dechlorinator 3 is connected to the outlet end of the Roots blower 2. The dechlorinator 3 contains dechlorination substances such as zinc oxide and aluminum oxide, which can reduce the chlorine in the exhaust gas to 0.1 ppm. The exhaust gas delivered by the Roots blower 2 first undergoes dechlorination in the dechlorinator 3. Subsequently, a first deoxygenator 4 and a second deoxygenator 5 are sequentially connected to the outlet end of the dechlorinator 3. Since the sodium chlorate exhaust gas has a high oxygen content, the first deoxygenator 4 and the second deoxygenator 5 are used to perform multi-stage purification of the exhaust gas, thereby removing the oxygen contained in the exhaust gas.

[0018] Specifically, the first deoxidizer 4 and the second deoxidizer 5 are equipped with metal target deoxidation catalysts. After the exhaust gas passes through the first deoxidizer 4, the first deoxidizer 4 can remove 70% of the oxygen in the exhaust gas. Then the exhaust gas enters the second deoxidizer 5, which can further remove the oxygen in the exhaust gas to 1 ppm, thus completing the removal of the high oxygen content in the exhaust gas.

[0019] In a preferred embodiment, since the deoxygenation processes in the first deoxygenator 4 and the second deoxygenator 5 are both exothermic reactions, to ensure the safety of the deoxygenation process, the first deoxygenator 4 and the second deoxygenator 5 are respectively connected to a first cooling pipeline 14 and a second cooling pipeline 15. The first cooling pipeline 14 and the second cooling pipeline 15 are used to provide a cold source for the first deoxygenator 4 and the second deoxygenator 5 to cool them down. The outlet end of the second deoxygenator 5 is sequentially connected to a first cooler 6 and a dryer 7. Since water is produced during the exhaust gas deoxygenation process, and the deoxygenation process is an exothermic reaction, the first cooler 6 is set after the second deoxygenator 5 to reduce the exhaust gas temperature to below 40°C before it enters the dryer 7 to remove the water. Thus, high-purity hydrogen can be obtained.

[0020] In a preferred embodiment, the dryer 7 is connected to a PSA system 9, which is connected to a discharge line 10. The PSA system 9 is an existing pressure swing adsorption system, which can further remove impurities in the exhaust gas to obtain high-purity hydrogen. The high-purity hydrogen is discharged and collected from the discharge line 10. Furthermore, a compressor 8 is connected between the dryer 7 and the PSA system 9. The compressor 8 can regulate the pressure of the exhaust gas delivered from the dryer 7, allowing it to enter the PSA system 9 at a higher pressure. This facilitates further pressure swing adsorption purification of the exhaust gas by the PSA system 9 to obtain high-purity hydrogen.

[0021] In a preferred embodiment, the discharge pipeline 10 is connected to a return gas pipeline 11, which is connected to a second cooler 12 and an exhaust fan 13. The exhaust pressure of the exhaust fan 13 is lower than that of the Roots blower 2. The exhaust fan 13 is connected to a first cooling pipeline 14 and a second cooling pipeline 15. All pipelines, including the return gas pipeline 11, the first cooling pipeline 14, and the second cooling pipeline 15, are equipped with one-way shut-off valves. After the discharge pipeline 10 discharges most of the high-purity hydrogen, the return gas pipeline 11 cools a small portion of the high-purity hydrogen through the second cooler 12. The cooled high-purity hydrogen then enters the first deoxidizer 4 and the second deoxidizer 5 via the first cooling pipeline 14 and the second cooling pipeline 15, respectively, to provide a cooling source for the first deoxidizer 4 and the second deoxidizer 5, ensuring the safety of the deoxidation process.

[0022] Of course, the first cooling pipeline 14 and the second cooling pipeline 15 can also be connected to external high-purity hydrogen. After the external high-purity hydrogen is cooled down, it enters the first cooling pipeline 14 and the second cooling pipeline 15 to cool down the deoxygenation reaction in the first deoxygenator 4 and the second deoxygenator 5. This utility model does not make any special limitations on it.

[0023] The preferred embodiments and examples of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments and examples. Within the scope of knowledge possessed by those skilled in the art, various changes or equivalent substitutions can be made without departing from the concept of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A high-oxygen, hydrogen-rich tail gas purification device for sodium chlorate, comprising a tail gas pipeline (1) and a Roots blower (2) connected to the tail gas pipeline (1), characterized in that: The outlet end of the Roots blower (2) is connected to a dechlorinator (3), and the outlet end of the dechlorinator (3) is sequentially connected to a first deoxygenator (4) and a second deoxygenator (5). The first deoxygenator (4) and the second deoxygenator (5) are respectively connected to a first cooling pipeline (14) and a second cooling pipeline (15). The outlet end of the second deoxygenator (5) is sequentially connected to a first cooler (6) and a dryer (7). The dryer (7) is connected to a PSA system (9), and the PSA system (9) is connected to a discharge pipeline (10).

2. The high-oxygen, hydrogen-rich tail gas purification equipment for sodium chlorate according to claim 1, characterized in that: The discharge pipeline (10) is connected to the return gas pipeline (11), the return gas pipeline (11) is connected to the second cooler (12) and the exhaust fan (13), and the exhaust fan (13) is connected to the first cooling pipeline (14) and the second cooling pipeline (15) respectively.

3. The high-oxygen, hydrogen-rich tail gas purification equipment for sodium chlorate according to claim 2, characterized in that: The return gas line (11), the first cooling line (14) and the second cooling line (15) are all equipped with one-way shut-off valves.

4. The high-oxygen, hydrogen-rich tail gas purification equipment for sodium chlorate according to claim 1, characterized in that: The first cooling line (14) and the second cooling line (15) are respectively connected to external high-purity hydrogen.

5. The high-oxygen, hydrogen-rich tail gas purification device for sodium chlorate according to claim 1, characterized in that: A compressor (8) is connected between the dryer (7) and the PSA system (9).

6. The high-oxygen, hydrogen-rich tail gas purification equipment for sodium chlorate according to claim 1, characterized in that: The Roots blower (2) is an oil-free Roots blower.

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