Method and device for purifying hydrogen sulfide gas

Abstract

The invention relates to a method for purifying hydrogen sulfide gas, which comprises the following steps: introducing crude hydrogen sulfide gas into a first adsorption tower filled with a modified 5A molecular sieve; introducing the hydrogen sulfide gas adsorbed by the first adsorption tower into a second adsorption tower filled with a modified 5A molecular sieve; introducing the hydrogen sulfide gas adsorbed by the second adsorption tower into a low-temperature storage tank, and condensing the hydrogen sulfide gas into a solid state in the low-temperature storage tank; and vacuumizing the low-temperature storage tank to negative pressure, slowly raising the temperature of the low-temperature storage tank, gasifying the hydrogen sulfide in the low-temperature storage tank, and filling the gasified hydrogen sulfide into a product collecting bottle to obtain a hydrogen sulfide product with the purity of more than 99.99%. Through the first adsorption tower and the second adsorption tower which are arranged in sequence, hydrogen sulfide is sequentially subjected to normal-temperature adsorption and cryogenic adsorption by using a modified 5A molecular sieve, so that impurities such as carbon dioxide and water in hydrogen sulfide gas can be effectively removed, and low-boiling-point impurities such as hydrogen and nitrogen can be effectively removed by vacuumizing the low-temperature storage tank; the product purity is favorably improved.

Description

Technical Field

[0001] The invention relates to the field of gas purification, and in particular to a method and a device for purifying hydrogen sulfide gas. Background Art

[0002] High-purity hydrogen sulfide is an important electronic gas, which is used in the preparation of optical and electronic devices in processes such as CVD and doping. In addition to semiconductors, hydrogen sulfide gas plays an important role in national defense chemical industry, electroluminescence, photoconductors and photovoltaics.

[0003] Patent CN108392948A discloses a hydrogen sulfide purification process and device, which uses multi-stage pressure swing adsorption to treat methanol-washed acid gas, and uses different molecular sieves such as alumina, silica gel, zeolite, and activated carbon to adsorb gas phase impurities to obtain a hydrogen sulfide product with a purity greater than 92%. This method is complex and the product purity is low.

[0004] Patent CN112408336A provides a process combining liquid absorption and rectification, wherein part of the impurity solvent of the crude hydrogen sulfide product is adsorbed and liquefied to obtain a first crude hydrogen sulfide product; the first crude hydrogen sulfide product is fractionated to obtain a second crude hydrogen sulfide product and light waste gas; the second crude hydrogen sulfide product is fractionated to obtain hydrogen sulfide gas and heavy impurity products, and a hydrogen sulfide product with a content of 99.99% is obtained. This method is relatively complex and has high energy consumption.

[0005] A difficult problem to solve in the process of hydrogen sulfide gas purification is how to remove impurities such as water, carbon dioxide, and hydrogen. Therefore, it is urgent to invent a method for purifying hydrogen sulfide gas that can remove impurities simply, economically and efficiently. Summary of the invention

[0006] In order to overcome the above problems existing in the prior art, the object of the present invention is to provide a method and device for purifying hydrogen sulfide gas, which can remove impurities simply, economically and efficiently.

[0007] To achieve the purpose of the present invention, the specific technical solutions provided by the present invention are as follows:

[0008] A device for purifying hydrogen sulfide gas comprises a first adsorption tower, a second adsorption tower and a cryogenic storage tank which are connected in sequence;

[0009] The first adsorption tower is provided with a first adsorption tower feed inlet at the bottom and a first adsorption tower discharge port at the top;

[0010] The second adsorption tower is provided with a second adsorption tower feed port at the bottom and a second adsorption tower discharge port at the top;

[0011] The top of the cryogenic storage tank is provided with a cryogenic storage tank feed port and a cryogenic storage tank discharge port;

[0012] The feed port of the first adsorption tower is connected to the crude hydrogen sulfide gas source through a pipeline, the discharge port of the first adsorption tower is connected to the feed port of the second adsorption tower through a pipeline, the discharge port of the second adsorption tower is connected to the feed port of the low-temperature storage tank through a pipeline, and the discharge port of the low-temperature storage tank is connected to the product collection bottle.

[0013] Preferably, a silicone coil is wound around the outside of the second adsorption tower, and the silicone coil is connected to a low-temperature constant-temperature reaction bath, and a 60% concentration ethylene glycol aqueous solution circulates through the low-temperature constant-temperature reaction bath in the silicone coil; the diameter of the silicone coil is 12 mm, and the ratio of the diameter of the silicone coil to the diameter of the second adsorption tower is 0.26:1.

[0014] Preferably, a cryogenic tank exhaust port is also provided on the top of the cryogenic tank, and the cryogenic tank exhaust port is connected to the vacuum pump through a pipeline.

[0015] Preferably, the cryogenic storage tank is provided with a jacket on the outside, the jacket is provided with a liquid nitrogen inlet and a cold nitrogen outlet, and the liquid nitrogen inlet of the jacket is connected to the liquid nitrogen tank.

[0016] Preferably, a liquid nitrogen tank discharge port is provided at the bottom of the liquid nitrogen tank, and the liquid nitrogen tank discharge port is connected to the liquid nitrogen inlet of the low-temperature storage tank jacket through a pipeline.

[0017] Preferably, the ratio of the diameter to the height of the first adsorption tower to the second adsorption tower is 45:1000, and the first adsorption tower and the second adsorption tower are both filled with modified 5A molecular sieve.

[0018] The present invention also provides a method for purifying hydrogen sulfide gas, which is implemented using a device for purifying hydrogen sulfide gas and comprises the following steps:

[0019] S1. The crude hydrogen sulfide gas is passed into the first adsorption tower filled with modified 5A molecular sieve, and the temperature of the first adsorption tower is controlled at 15°C to 35°C, and the pressure is controlled at 0.6MPa to 1MPa;

[0020] S2, passing the hydrogen sulfide gas adsorbed by the first adsorption tower into the second adsorption tower equipped with modified 5A molecular sieve, the temperature is controlled at -50°C to -30°C, and the pressure is controlled at 0.5MPa to 0.8MPa;

[0021] S3, passing the hydrogen sulfide gas adsorbed by the second adsorption tower into a cryogenic storage tank, where the hydrogen sulfide gas is condensed into a solid state;

[0022] S4. Evacuate the cryogenic storage tank to negative pressure for 10 minutes, then stop evacuating and close the liquid nitrogen inlet of the cryogenic storage tank jacket, slowly increase the temperature of the cryogenic storage tank, and gasify the hydrogen sulfide in the cryogenic storage tank and fill it into the product collection bottle to obtain a hydrogen sulfide product with a purity greater than 99.99%.

[0023] Preferably, the modification method of the 5A molecular sieve is: soaking the 5A molecular sieve in a mixed solution of 10% dilute nitric acid and saturated hydrosulfuric acid in a volume ratio of 10:1 to 30:1 for 2h-4h, taking it out and placing it in a forced air drying oven, and drying it at a temperature of 80°C-100°C for 8h-10h.

[0024] Preferably, in step S1, the flow rate of the crude hydrogen sulfide gas introduced is 3-5 L / min, and the purity of hydrogen sulfide is 99.5%.

[0025] Preferably, in step S3, the low-temperature storage tank is cooled by liquid nitrogen, and the temperature of the storage tank is controlled to be -120°C to -90°C.

[0026] A method and device for purifying hydrogen sulfide gas of the present invention has the following advantages:

[0027] 1. The present invention uses the adsorption performance of the modified 5A molecular sieve to effectively remove impurities in hydrogen sulfide gas and improve the purity of hydrogen sulfide gas by sequentially arranging the first adsorption tower and the second adsorption tower. The modified 5A molecular sieve is used to sequentially adsorb hydrogen sulfide at room temperature and deep cold, thereby reducing the adsorption amount of hydrogen sulfide by the conventional 5A molecular sieve and enhancing the adsorption effect on carbon dioxide and water.

[0028] 2. The present invention further ensures the purity of hydrogen sulfide gas by setting up a low-temperature storage tank, so that the final product quality is higher. The adsorbed gas is treated by a freezing and negative extraction method, which can effectively remove low-boiling point impurities such as hydrogen and nitrogen that are difficult to remove by adsorption, which is beneficial to improving product purity.

[0029] 3. The method and device of the present invention have simple structure, easy operation, no need for complicated equipment and process, and reduce production cost. In addition, through reasonable pipeline design and size ratio of adsorption tower, the whole purification process is more efficient and the waste of energy and resources is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of a device for purifying hydrogen sulfide gas according to the present invention;

[0031] Explanation of the markings in the figure: 1. Crude hydrogen sulfide gas source; 2. First adsorption tower; 3. Second adsorption tower; 4. Silica gel coil; 5. Low-temperature constant temperature reaction bath; 6. Low-temperature storage tank; 7. Vacuum pump; 8. Product collection bottle; 9. Liquid nitrogen tank. DETAILED DESCRIPTION

[0032] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation method, structure, characteristics and effects of the present invention are described in detail below in combination with the preferred embodiments.

[0033] Device Example 1

[0034] like Figure 1 , which is a schematic diagram of a device for purifying hydrogen sulfide gas according to the present invention;

[0035] A device for purifying hydrogen sulfide gas, comprising a crude hydrogen sulfide gas source 1, a first adsorption tower 2, a second adsorption tower 3, a low-temperature storage tank 6 and a product collecting bottle 8 connected in sequence;

[0036] The first adsorption tower 2 has a first adsorption tower feed port at the bottom and a first adsorption tower discharge port at the top;

[0037] The second adsorption tower 3 has a second adsorption tower feed port at the bottom and a second adsorption tower discharge port at the top;

[0038] The top of the cryogenic storage tank 6 is provided with a cryogenic storage tank feed port, a cryogenic storage tank discharge port and a cryogenic storage tank exhaust port.

[0039] The feed port of the first adsorption tower is connected to the crude hydrogen sulfide gas source 1 through a pipeline; the discharge port of the first adsorption tower is connected to the feed port of the second adsorption tower through a pipeline, a silicone coil 4 is wound around the outside of the second adsorption tower 3, the silicone coil 4 is connected to a low-temperature constant-temperature reaction bath 5, and the silicone coil 4 contains a 60% concentration ethylene glycol aqueous solution circulating through the low-temperature constant-temperature reaction bath 5; the diameter of the silicone coil 4 is 12 mm, and the ratio of the diameter of the silicone coil 4 to the diameter of the second adsorption tower 3 is 0.26:1; the diameter and height ratio of the first adsorption tower 2 is 45:1000, and the diameter and height ratio of the second adsorption tower 3 is 45:1000.

[0040] Through reasonable pipeline design and adsorption tower size ratio, the entire purification process is made more efficient and the waste of energy and resources is reduced.

[0041] The first adsorption tower 2 and the second adsorption tower 3 are both filled with modified 5A molecular sieves;

[0042] By sequentially arranging the first adsorption tower 2 and the second adsorption tower 3, the adsorption performance of the modified 5A molecular sieve is utilized to effectively remove impurities in the hydrogen sulfide gas and improve the purity of the hydrogen sulfide gas. The modified 5A molecular sieve is used to sequentially adsorb hydrogen sulfide at room temperature and deep cold, thereby reducing the adsorption amount of hydrogen sulfide by the conventional 5A molecular sieve and enhancing the adsorption effect on carbon dioxide and water.

[0043] The discharge port of the second adsorption tower is connected to the feed port of the low-temperature storage tank through a pipeline, the exhaust port of the low-temperature storage tank is connected to the vacuum pump 7 through a pipeline, and the discharge port of the low-temperature storage tank is connected to the product collecting bottle 8; a jacket is provided on the outside of the low-temperature storage tank 6, and a liquid nitrogen inlet and a cold nitrogen outlet are provided on the jacket, the liquid nitrogen inlet of the jacket is connected to the liquid nitrogen tank 9, and a liquid nitrogen tank discharge port is provided at the bottom of the side wall of the liquid nitrogen tank 9, and specifically, the liquid nitrogen tank discharge port is connected to the liquid nitrogen inlet of the jacket through a pipeline.

[0044] The setting of the low-temperature storage tank 6 further ensures the purity of the hydrogen sulfide gas, so that the final product quality is higher. The adsorbed gas is treated by the method of freezing and pumping, which can effectively remove low-boiling point impurities such as hydrogen and nitrogen that are difficult to remove by adsorption, which is beneficial to improving the purity of the product.

[0045] Valves are provided on the connecting pipes between the crude hydrogen sulfide gas source 1, the first adsorption tower 2, the second adsorption tower 3, the low-temperature storage tank 6 and the product collecting bottle 8.

[0046] The device for purifying hydrogen sulfide gas disclosed in the present application has a simple structure and is easy to operate, does not require complicated equipment and processes, and reduces production costs.

[0047] The modification method of the modified 5A molecular sieve is as follows: immerse the 5A molecular sieve in a mixed solution of 10% dilute nitric acid and saturated hydrosulfuric acid in a volume ratio of 20:1 for 3 hours, take it out and place it in a forced air drying oven, and dry it at a temperature of 95°C for 10 hours. Method Examples 1-3 of the present application all use the modified 5A molecular sieve prepared by this method.

[0048] Method Example 1

[0049] A method for purifying hydrogen sulfide gas, using a device for purifying hydrogen sulfide gas of a device embodiment, comprises the following steps:

[0050] S1, passing crude hydrogen sulfide gas with a purity of 99.5% into a first adsorption tower 2 filled with modified 5A molecular sieve at a flow rate of 5L / min, the temperature of the first adsorption tower 2 is controlled at 20°C, and the pressure is controlled at 0.6MPa-1MPa;

[0051] S2, passing the hydrogen sulfide gas adsorbed by the first adsorption tower 2 into the second adsorption tower 3 filled with modified 5A molecular sieve, the temperature is controlled at -50 ° C, and the pressure is controlled at 0.5 MPa to 0.8 MPa;

[0052] S3, passing the hydrogen sulfide gas adsorbed by the second adsorption tower 3 into the cryogenic storage tank 6, where the hydrogen sulfide gas is condensed into a solid state. The refrigerant of the cryogenic storage tank 6 is liquid nitrogen, and the tank temperature is controlled at -90°C;

[0053] S4. Evacuate the cryogenic storage tank 6 to negative pressure for 10 minutes, then stop evacuating, close the liquid nitrogen inlet on the jacket, and slowly increase the temperature of the cryogenic storage tank 6. The hydrogen sulfide in the cryogenic storage tank 6 is gasified and filled into the product collection bottle 8 to obtain a hydrogen sulfide product with a purity of 99.992%.

[0054] Method Example 2

[0055] A method for purifying hydrogen sulfide gas, using a device for purifying hydrogen sulfide gas of a device embodiment, comprises the following steps:

[0056] S1, passing crude hydrogen sulfide gas with a purity of 99.5% into a first adsorption tower 2 filled with modified 5A molecular sieve at a flow rate of 4 L / min, the temperature of the first adsorption tower 2 is controlled at 35° C., and the pressure is controlled at 0.6 MPa to 1 MPa;

[0057] S2, passing the hydrogen sulfide gas adsorbed by the first adsorption tower 2 into the second adsorption tower 3 filled with modified 5A molecular sieve, the temperature is controlled at -40 ° C, and the pressure is controlled at 0.5 MPa to 0.8 MPa;

[0058] S3, passing the hydrogen sulfide gas adsorbed by the second adsorption tower 3 into the cryogenic storage tank 6, where the hydrogen sulfide gas is condensed into a solid state. The refrigerant of the cryogenic storage tank 6 is liquid nitrogen, and the tank temperature is controlled at -100°C;

[0059] S4, evacuate the cryogenic storage tank 6 to negative pressure, then slowly increase the temperature of the cryogenic storage tank 6, and fill the hydrogen sulfide in the cryogenic storage tank 6 into the product collection bottle 8 after gasification, to obtain a hydrogen sulfide product with a purity of 99.994%.

[0060] Method Example 3

[0061] A method for purifying hydrogen sulfide gas, using a device for purifying hydrogen sulfide gas of a device embodiment, comprises the following steps:

[0062] S1, the crude hydrogen sulfide gas with a purity of 99.5% is passed into the first adsorption tower 2 filled with modified 5A molecular sieve at a flow rate of 3L / min, the temperature of the first adsorption tower 2 is controlled at 15°C, and the pressure is controlled at 0.6MPa-1MPa;

[0063] S2, passing the hydrogen sulfide gas adsorbed by the first adsorption tower 2 into the second adsorption tower 3 filled with modified 5A molecular sieve, the temperature is controlled at -30 ° C, and the pressure is controlled at 0.5 MPa to 0.8 MPa;

[0064] S3, passing the hydrogen sulfide gas adsorbed by the second adsorption tower 3 into the cryogenic storage tank 6, where the hydrogen sulfide gas is condensed into a solid state. The refrigerant of the cryogenic storage tank 6 is liquid nitrogen, and the tank temperature is controlled at -120°C;

[0065] S4, evacuate the cryogenic storage tank 6 to negative pressure, then slowly increase the temperature of the cryogenic storage tank 6, and fill the hydrogen sulfide in the cryogenic storage tank 6 into the product collection bottle 8 after gasification, to obtain a hydrogen sulfide product with a purity of 99.995%.

[0066] Comparative Example 1

[0067] The difference from method example 1 is that common 5A molecular sieve adsorbent is used in the first adsorption tower 2 and the second adsorption tower 3, and the other steps and parameters remain unchanged, and finally a hydrogen sulfide product with a purity of 99.94% is obtained.

[0068] Comparative Example 2

[0069] The difference from method example 1 is that the temperature of the second adsorption tower 3 is also controlled to be room temperature 20° C., and the other steps and parameters remain unchanged, and finally a hydrogen sulfide product with a purity of 99.98% is obtained.

[0070] The present invention can effectively remove impurities in hydrogen sulfide gas and improve the purity of hydrogen sulfide gas by sequentially arranging a first adsorption tower 2 and a second adsorption tower 3 and utilizing the adsorption performance of a modified 5A molecular sieve. The modified 5A molecular sieve is used to sequentially adsorb hydrogen sulfide at room temperature and deep cold, thereby reducing the adsorption amount of hydrogen sulfide by a conventional 5A molecular sieve and enhancing the adsorption effect on carbon dioxide and water.

[0071] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as above based on the preferred embodiment, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A device for purifying hydrogen sulfide gas, characterized in that: It includes a first adsorption tower, a second adsorption tower and a low-temperature storage tank which are connected in sequence; The first adsorption tower is provided with a first adsorption tower feed inlet at the bottom and a first adsorption tower discharge port at the top; The second adsorption tower is provided with a second adsorption tower feed port at the bottom and a second adsorption tower discharge port at the top; The top of the cryogenic storage tank is provided with a cryogenic storage tank feed port and a cryogenic storage tank discharge port; The feed port of the first adsorption tower is connected to the crude hydrogen sulfide gas source through a pipeline, the discharge port of the first adsorption tower is connected to the feed port of the second adsorption tower through a pipeline, the discharge port of the second adsorption tower is connected to the feed port of the low-temperature storage tank through a pipeline, and the discharge port of the low-temperature storage tank is connected to the product collection bottle.

2. The device for purifying hydrogen sulfide gas according to claim 1, characterized in that: A silicone coil is wound around the outside of the second adsorption tower, and the silicone coil is connected to a low-temperature constant-temperature reaction bath. The silicone coil contains a 60% volume concentration ethylene glycol aqueous solution that circulates through the low-temperature constant-temperature reaction bath; the diameter of the silicone coil is 12 mm, and the ratio of the diameter of the silicone coil to the diameter of the second adsorption tower is 0.26:

1.

3. The device for purifying hydrogen sulfide gas according to claim 1, characterized in that: The top of the cryogenic tank is also provided with a cryogenic tank exhaust port, and the cryogenic tank exhaust port is connected with the vacuum pump through a pipeline.

4. The device for purifying hydrogen sulfide gas according to claim 1, characterized in that: A jacket is arranged outside the low-temperature storage tank, a liquid nitrogen inlet and a cold nitrogen outlet are arranged on the jacket, and the liquid nitrogen inlet of the jacket is communicated with the liquid nitrogen tank.

5. The device for purifying hydrogen sulfide gas according to claim 4, characterized in that: A liquid nitrogen tank discharge port is provided at the bottom of the liquid nitrogen tank, and the liquid nitrogen tank discharge port is communicated with the liquid nitrogen inlet of the low-temperature storage tank jacket through a pipeline.

6. The device for purifying hydrogen sulfide gas according to claim 1, characterized in that: The ratio of the diameter to the height of the first adsorption tower to the second adsorption tower is 45:1000, and the first adsorption tower and the second adsorption tower are both filled with modified 5A molecular sieves.

7. A method for purifying hydrogen sulfide gas, using the device for purifying hydrogen sulfide gas according to any one of claims 1 to 7, characterized in that: The steps include: S1. The crude hydrogen sulfide gas is passed into the first adsorption tower filled with modified 5A molecular sieve, and the temperature of the first adsorption tower is controlled at 15°C to 35°C, and the pressure is controlled at 0.6MPa to 1MPa; S2, passing the hydrogen sulfide gas adsorbed by the first adsorption tower into the second adsorption tower equipped with modified 5A molecular sieve, the temperature is controlled at -50°C to -30°C, and the pressure is controlled at 0.5MPa to 0.8MPa; S3, passing the hydrogen sulfide gas adsorbed by the second adsorption tower into a cryogenic storage tank, where the hydrogen sulfide gas is condensed into a solid state; S4. Evacuate the cryogenic storage tank to negative pressure for 10 minutes, then stop evacuating and close the liquid nitrogen inlet of the cryogenic storage tank jacket, slowly increase the temperature of the cryogenic storage tank, and gasify the hydrogen sulfide in the cryogenic storage tank and fill it into the product collection bottle to obtain a hydrogen sulfide product with a purity greater than 99.99%.

8. A method for purifying hydrogen sulfide gas according to claim 8, characterized in that: The modification method of the 5A molecular sieve is as follows: immersing the 5A molecular sieve in a mixed solution of 10% mass concentration of dilute nitric acid and saturated hydrosulfuric acid in a volume ratio of 10:1 to 30:1 for 2h-4h, taking it out and placing it in a forced air drying oven, and drying it at a temperature of 80°C-100°C for 8h-10h.

9. A method for purifying hydrogen sulfide gas according to claim 8, characterized in that: In step S1, the flow rate of the crude hydrogen sulfide gas introduced is 3-5 L / min, and the purity of hydrogen sulfide is 99.5%.

10. A method for purifying hydrogen sulfide gas according to claim 8, characterized in that: In step S3, the low-temperature storage tank is cooled by liquid nitrogen, and the temperature of the storage tank is controlled to be -120°C to -90°C.

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