Helium purification system

Abstract

The utility model discloses a helium purification system, which belongs to the technical field of helium purification, and comprises a dehydrogenation unit, a purification unit and a control unit, and is characterized in that the dehydrogenation unit is used for dehydrogenating crude helium conveyed from a substation; the drying unit is used for dehydrating the dehydrogenated crude helium; the PSA unit is used for performing pressure swing adsorption on the dried crude helium to remove foreign gases except helium; the low-temperature purification unit is used for carrying out trace impurity adsorption on the helium subjected to impurity removal; according to hydrogen contained in raw material gas, hydrogen in crude helium is converted into water through the dehydrogenation unit, then the water is absorbed through the drying unit, so that hydrogen removal is achieved, the dehydrogenated and dried crude helium enters the PSA unit, other impurity gases except the helium are removed in a pressure swing adsorption mode, and the hydrogen in the crude helium is removed. Then the helium treated by the PSA unit enters a low-temperature adsorption purification unit, all trace impurities except the helium are adsorbed, and a helium product with the concentration larger than or equal to 99.999% (Vol) is obtained.

Description

Technical Field

[0001] This utility model relates to the field of helium purification technology, specifically a helium purification system. Background Technology

[0002] Helium, as a rare gas with an irreplaceable role in many key fields, occupies a pivotal position in the development of modern industry and technology.

[0003] Currently, helium production facilities produce helium with low purity, containing impurities such as nitrogen, trace amounts of argon, neon, oxygen, and methane. Conventional processes are energy-intensive, and the removal of some impurities is difficult to control, ultimately resulting in helium with substandard purity. Summary of the Invention

[0004] To address the problems of existing technologies, this utility model provides a helium purification system, comprising: a dehydrogenation unit for dehydrogenating crude helium delivered from a substation;

[0005] The drying unit is used to dehydrate the crude helium gas after dehydrogenation.

[0006] The PSA unit is used to remove impurity gases other than helium from dried crude helium gas by pressure swing adsorption.

[0007] The low-temperature purification unit is used to adsorb trace impurities from the purified helium gas.

[0008] One end of the dehydrogenation unit is connected to the substation, the other end of the dehydrogenation unit is connected to one end of the drying unit, the other end of the drying unit is connected to one end of the PSA unit, the other end of the PSA unit is connected to one end of the low-temperature purification unit, and the other end of the low-temperature purification unit is connected to the helium storage tank.

[0009] Furthermore, the dehydrogenation unit includes: a dehydrogenation tower, which is filled with a high-efficiency catalyst, and the high-efficiency catalyst reacts with hydrogen to produce water;

[0010] The two ends of the dehydrogenation tower are connected to the substation and the drying unit, respectively.

[0011] Furthermore, the drying unit is a dryer, and the dryer contains a drying adsorbent.

[0012] Furthermore, the PSA unit includes: multiple adsorption towers, a forward venting buffer tank, a reverse venting buffer tank, and a desorption gas mixing tank;

[0013] The adsorption towers are connected in sequence by pipes to form a closed loop, and the bottom of one of the adsorption towers is connected to the dryer.

[0014] The last adsorption tower through which the helium gas passes is connected to the low-temperature purification unit.

[0015] The venting buffer tank is connected to the venting outlet of the last adsorption tower through which the helium gas passes;

[0016] The reverse venting buffer tank is connected to the reverse venting outlet of the last adsorption tower through which the helium gas passes.

[0017] The desorbed gas mixing tank is connected to the reverse release buffer tank and the desorbed gas buffer tank.

[0018] Furthermore, the low-temperature purification unit is a low-temperature adsorber.

[0019] Furthermore, a pressurization unit is provided between the cryogenic purification unit and the helium storage tank, and the pressurization unit is a filling pressurizer.

[0020] Furthermore, the system also includes a desorption gas recovery and pressurization unit and a helium recovery and pressurization unit;

[0021] The desorbed gas recovery and booster unit includes a desorbed gas compressor;

[0022] The helium recovery booster unit includes a helium recovery booster;

[0023] The desorbed gas recovery and pressurization unit is connected to the PSA unit and the low-temperature purification unit, respectively;

[0024] The desorbed gas recovery and pressurization unit is connected to the recovered helium pressurization unit via a separation unit, and the recovered helium pressurization unit is connected to the dehydrogenation unit.

[0025] Furthermore, the separation unit includes: a filter, a primary membrane separator, and a secondary membrane separator;

[0026] The filter is connected to the desorbed gas recovery and pressurization unit and the first-stage membrane separator, respectively; the first-stage membrane separator is connected to the second-stage membrane separator and the helium recovery and pressurization unit, respectively.

[0027] The secondary membrane separator is connected to the desorbed gas recovery and pressurization unit.

[0028] The beneficial effects of this utility model are:

[0029] The hydrogen in the raw helium gas is converted into water by a dehydrogenation unit. The water is then absorbed by a drying unit, thus removing the hydrogen. The dehydrogenated and dried raw helium gas enters a PSA unit, where other impurities besides helium are removed by pressure swing adsorption. The helium gas treated by the PSA unit then enters a low-temperature adsorption purification unit, where all trace impurities except helium are adsorbed to obtain a helium product with a concentration ≥99.999% (Vol). Attached Figure Description

[0030] Figure 1 A schematic diagram of the framework of the helium purification system provided by this utility model.

[0031] Figure label:

[0032] In the diagram: 1 is the dehydrogenation unit, 2 is the drying unit, 3 is the PSA unit, 4 is the low-temperature purification unit, 5 is the pressurization unit, 6 is the desorbed gas recovery pressurization unit, 7 is the helium recovery pressurization unit, 8 is the filter, 9 is the primary membrane separator, and 10 is the secondary membrane separator. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please see Figure 1 This utility model provides a helium purification system, including: a dehydrogenation unit 1, used to dehydrogenate crude helium delivered from a substation;

[0035] The dehydrogenation unit 1 includes: a dehydrogenation tower, which is filled with a high-efficiency catalyst, and the high-efficiency catalyst reacts with hydrogen to produce water;

[0036] The two ends of the dehydrogenation tower are connected to the substation and the drying unit 2, respectively;

[0037] Drying unit 2 is used to dehydrate the crude helium gas after dehydrogenation;

[0038] The drying unit 2 is a dryer, and the dryer is equipped with a drying adsorbent.

[0039] The raw gas contains approximately 14%–18% hydrogen, requiring oxygen catalytic removal. The dehydrogenation tower is filled with a highly efficient catalyst, which can remove hydrogen from the crude helium to below 0.1 ppm at room temperature. Since water is produced after the reaction of hydrogen and oxygen, it must also be removed. The gas exiting the catalytic oxidation tower contains a large amount of reacted water. It is first cooled by a cooler, then separated by gas-liquid separation, and finally enters a switching dehydration dryer, where the water content in the raw gas is reduced to below 1 ppm. After the dehydration drying adsorbent is saturated, it is regenerated by heating to restore its adsorption activity. Multiple dehydrogenation towers are installed, with at least two operating for water absorption and drying, and one for heating and regeneration, thus achieving continuous drying of the raw gas.

[0040] PSA unit 3 is used to remove impurity gases other than helium from dried crude helium gas by pressure swing adsorption; wherein, PSA unit 3 includes: multiple adsorption towers, one forward venting buffer tank, one reverse venting buffer tank and one desorption gas mixing tank.

[0041] The adsorption towers are connected in sequence by pipes to form a closed loop, and the bottom of one of the adsorption towers is connected to the dryer.

[0042] The last adsorption tower through which the helium gas passes is connected to the low-temperature purification unit 4.

[0043] The venting buffer tank is connected to the venting outlet of the last adsorption tower through which the helium gas passes;

[0044] The reverse venting buffer tank is connected to the reverse venting outlet of the last adsorption tower through which the helium gas passes.

[0045] The desorbed gas mixing tank is connected to the reverse release buffer tank and the desorbed gas buffer tank.

[0046] The connection methods for each device in the PSA unit are as follows:

[0047] Adsorption towers: Up to eight towers can be configured, connected sequentially via pipelines to form a closed loop. The feed gas enters from the bottom of one tower, undergoes adsorption treatment, and exits from the top. The gas then flows sequentially through the other towers, undergoing a continuous adsorption and regeneration process.

[0048] Forward venting buffer tank: The forward venting buffer tank is connected to the forward venting outlet of the adsorption tower and is used to store the gas discharged from the adsorption tower during the forward venting step. The forward venting buffer tank can stabilize the pressure and flow rate, ensuring the smooth discharge of the forward venting gas.

[0049] Backdraft buffer tank: The backdraft buffer tank is connected to the backdraft outlet of the adsorption tower and is used to store the gas discharged from the adsorption tower during the backdraft step. The backdraft buffer tank can collect and store backdraft gas for subsequent treatment or recycling.

[0050] Desorption gas mixing tank: The desorption gas mixing tank is connected to the backflow buffer tank and the desorption gas buffer tank, and is used to mix the backflow gas and the desorption gas. The desorption gas mixing tank can play a role in uniformly mixing the gases and ensuring the stability of the composition and pressure of the desorption gas.

[0051] Through the above connection methods, the various devices in the PSA unit work together to achieve the adsorption, separation and purification process of the raw gas, thereby obtaining high-purity product hydrogen and desorbed gas.

[0052] After being processed by the drying unit, crude helium is obtained, which contains impurities such as nitrogen, trace amounts of argon, neon, oxygen, and methane. The crude helium gas with a concentration of ≥70% (Vol) obtained from dehydrogenation drying enters the PSA unit, where other impurity gases besides helium are removed by pressure swing adsorption to obtain helium gas with a concentration of ≥99.5% (Vol).

[0053] The low-temperature purification unit 4 is used to adsorb trace impurities in the purified helium gas; the low-temperature purification unit 4 is a low-temperature adsorber.

[0054] In this process, helium gas from the PSA unit enters the low-temperature adsorption purification unit. After passing through the low-temperature adsorber, all trace impurities other than helium are adsorbed, resulting in a helium product with a concentration ≥99.999% (Vol).

[0055] One end of the dehydrogenation unit 1 is connected to the substation, the other end of the dehydrogenation unit 1 is connected to one end of the drying unit 2, the other end of the drying unit 2 is connected to one end of the PSA unit, the other end of the PSA unit 3 is connected to one end of the low-temperature purification unit 4, and the other end of the low-temperature purification unit 4 is connected to the helium storage tank.

[0056] In some embodiments, a pressurization unit 5 is provided between the cryogenic purification unit 4 and the helium storage tank, and the pressurization unit 5 is a filling pressurizer.

[0057] To facilitate the helium storage process, a filling compressor is installed with the following specifications: intake pressure: 1.5 MPa(G); intake temperature: <40℃; exhaust pressure: 20 MPa(G); exhaust temperature: ≤50℃ (after cooling); volumetric flow rate: 160 Nm3 / h. The filling compressor can quickly fill helium.

[0058] In some embodiments, the system further includes a desorption gas recovery and pressurization unit 6 and a helium recovery and pressurization unit 7;

[0059] The desorbed gas recovery and booster unit 6 includes a desorbed gas compressor;

[0060] The helium recovery booster unit 7 includes a helium recovery booster;

[0061] The desorbed gas recovery and pressurization unit 6 is connected to the PSA unit 3 and the low-temperature purification unit 4, respectively;

[0062] The desorbed gas recovery and pressurization unit 6 is connected to the recovered helium pressurization unit 7 via a separation unit, and the recovered helium pressurization unit 7 is connected to the dehydrogenation unit 1.

[0063] The separation unit includes: a filter 8, a primary membrane separator 9, and a secondary membrane separator 10;

[0064] The filter 8 is connected to the desorbed gas recovery and pressurization unit 6 and the first-stage membrane separator 9 respectively, and the first-stage membrane separator 9 is connected to the second-stage membrane separator 10 and the helium recovery and pressurization unit 7 respectively;

[0065] The secondary membrane separator 10 is connected to the desorbed gas recovery and pressurization unit 6.

[0066] Specifically, the regenerated gas and desorbed gas from the PSA unit and the cryogenic purification unit are pressurized and cooled by the desorbed gas compressor before entering the first-stage membrane separator of the membrane separation unit. The permeate is pressurized and cooled by the helium recovery compressor and then mixed with the feed gas before dehydrogenation drying before entering the dehydrogenation unit. The tail gas from the first-stage membrane separator enters the second-stage membrane separator, and the tail gas from the second-stage membrane separator enters the venting system. The permeate from the second-stage membrane separator returns to the inlet of the desorbed gas recovery and pressurization unit, where it is mixed with the PSA regenerated gas and the cryogenic purification desorbed gas before entering the desorbed gas compressor. Finally, after passing through the membrane separation skid, it enters the helium recovery pressurizer for pressurization and cooling before entering the dehydrogenation drying skid, thus achieving the purpose of recovery.

[0067] The above description is only a preferred embodiment of the present utility model and is 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 should be included within the protection scope of the present utility model.

Claims

1. A helium purification system, characterized by, The system comprises: a dehydrogenation unit for dehydrogenating crude helium gas delivered from a substation; a drying unit for dehydrating the crude helium gas after dehydrogenation; a PSA unit for pressure swing adsorption of the crude helium gas after drying to remove impurity gases other than helium; a low-temperature purification unit for adsorbing trace impurities from the helium gas after impurity removal; one end of the dehydrogenation unit is connected to the substation, the other end of the dehydrogenation unit is connected to one end of the drying unit, the other end of the drying unit is connected to one end of the PSA unit, the other end of the PSA unit is connected to one end of the low-temperature purification unit, and the other end of the low-temperature purification unit is connected to a helium storage tank; the PSA unit comprises a plurality of adsorption towers, a forward purge gas buffer tank, a reverse purge gas buffer tank, and a desorption gas mixing tank; the adsorption towers are connected in sequence by pipelines, and the bottom of one of the adsorption towers is connected to a dryer; the last adsorption tower through which the helium gas passes is connected to the low-temperature purification unit; the forward purge gas buffer tank is connected to the forward purge gas outlet of the last adsorption tower through which the helium gas passes; the reverse purge gas buffer tank is connected to the reverse purge gas outlet of the last adsorption tower through which the helium gas passes; the desorption gas mixing tank is connected to the reverse purge gas buffer tank and a desorption gas buffer tank; a booster unit is provided between the low-temperature purification unit and the helium storage tank, and the booster unit is a charging booster; the system further comprises a desorption gas recovery booster unit and a recovered helium gas booster unit; the desorption gas recovery booster unit comprises a desorption gas compressor; the recovered helium gas booster unit comprises a recovered helium gas booster; the desorption gas recovery booster unit is connected to the PSA unit and the low-temperature purification unit respectively; the desorption gas recovery booster unit is connected to the recovered helium gas booster unit through a separation unit, and the recovered helium gas booster unit is connected to the dehydrogenation unit; the separation unit comprises a filter, a primary membrane separator, and a secondary membrane separator; the filter is connected to the desorption gas recovery booster unit and the primary membrane separator respectively, the primary membrane separator is connected to the secondary membrane separator and the recovered helium gas booster unit respectively; the secondary membrane separator is connected to the desorption gas recovery booster unit.

2. The helium purification system of claim 1, wherein, The dehydrogenation unit comprises a dehydrogenation tower, the dehydrogenation tower is filled with high-efficiency catalyst, and the high-efficiency catalyst reacts with hydrogen to generate water; both ends of the dehydrogenation tower are connected to the substation and the drying unit respectively.

3. The helium purification system of claim 1, wherein, The drying unit is a dryer, and the dryer is provided with a drying adsorbent.

4. The helium purification system of claim 1, wherein, The low-temperature purification unit is a low-temperature adsorber.

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