Gas purification apparatus and gas purification method

Abstract

To provide a gas purification device that can efficiently recover and reuse exhaust gases. [Solution] The system includes adsorption towers 2A and 2B that remove impurities from the supplied raw material gas G1 to purify the gas; a raw material gas introduction path L1 that supplies the raw material gas G1 to one end of the adsorption towers 2A and 2B; a product gas discharge path L2 that discharges the purified gas from the other end of the adsorption towers 2A and 2B; an exhaust path L4 that discharges the exhaust gas G4 generated in the adsorption towers 2A and 2B; a buffer tank 5 that recovers at least a portion of the exhaust gas G4 passing through the exhaust path L4 so that it can be reused as recycled gas; and a recycled gas supply path L3 that connects the adsorption towers 2A and 2B to the buffer tank 5 and allows recycled gas G3 to flow into the buffer tank 5.

Description

Technical Field

[0001] The present invention relates to a gas purification apparatus and a gas purification method.

Background Art

[0002] Conventionally, for example, in a room-temperature air purification apparatus as disclosed in Patent Document 1, an apparatus that removes impurities such as moisture using a room-temperature adsorption cylinder is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a conventional room-temperature air purification apparatus, it is necessary to exhaust the purified gas in the purification cylinder before heating and regenerating the room-temperature adsorption cylinder, and after heating and regeneration, it is necessary to pressurize using a part of the purified gas. Therefore, it has been required that a large amount of the purified gas exhausted before regeneration can be reused, and there has been room for improvement in this regard.

[0005] Therefore, the present invention has been made in view of the above circumstances, and provides a gas purification apparatus and a gas purification method capable of efficiently recovering and reusing exhaust gas.

Means for Solving the Problems

[0006] In order to achieve the above object, the present invention employs the following means. In other words, the gas purification apparatus according to the present invention comprises: a purification cylinder for purifying purified gas by removing impurities from a supplied raw material gas; a raw material gas introduction path for supplying the raw material gas to one end of the purification cylinder; a product gas discharge path for dischargeing the purified gas from the other end of the purification cylinder; an exhaust path for exhausting exhaust gas generated in the purification cylinder; a buffer tank for recovering at least a portion of the exhaust gas passing through the exhaust path so that it can be reused as reusable gas; and a reusable gas supply path for connecting the purification cylinder and the buffer tank and for allowing the reusable gas to flow into the buffer tank.

[0007] Furthermore, the gas purification apparatus according to the present invention may be configured such that the reuse gas supply path includes a first reuse gas supply path connecting the buffer tank and the exhaust side of the purification cylinder, and a second reuse gas supply path connecting the buffer tank and the purified gas outlet side of the purification cylinder, and when the purification cylinder is regenerated, at least a portion of the exhaust gas generated in the purification cylinder is filled into the buffer tank through the first reuse gas supply path to release pressure inside the purification cylinder before heating and regeneration, and after heating and regeneration, the reuse gas is filled into the purification cylinder from the buffer tank through the second reuse gas supply path to fill pressure inside the purification cylinder.

[0008] Furthermore, in the gas purification apparatus according to the present invention, a plurality of purification cylinders may be provided, and the apparatus may be configured to allow for regeneration processing in other purification cylinders in parallel with the purification processing in at least one of the plurality of purification cylinders.

[0009] Furthermore, in the gas purification apparatus according to the present invention, the purification cylinder may be provided with a heating means for heating the recycled gas inside the purification cylinder.

[0010] Furthermore, in the gas purification apparatus according to the present invention, the reuse gas supply path may be configured to include a third reuse gas supply path that connects from the buffer tank to an external reuse facility.

[0011] Furthermore, the gas purification method according to the present invention is characterized by comprising: a raw material gas introduction step of supplying the raw material gas to one end of the purification cylinder; a gas purification step of removing impurities in the supplied raw material gas with the purification cylinder to purify the purified gas; a product gas discharge step of dischargeing the purified gas from the other end of the purification cylinder; an exhaust step of exhausting the exhaust gas generated in the purification cylinder; and a reuse gas recovery step of recovering at least a portion of the exhaust gas into a buffer tank so that it can be reused as reuse gas.

[0012] Furthermore, the gas purification method according to the present invention may be characterized by having, when regenerating the purification cylinder, a reuse gas recovery step is performed in which, before heating and regeneration, at least a portion of the exhaust gas generated in the purification cylinder is recovered in the buffer tank to release pressure inside the purification cylinder, and after heating and regeneration, the reuse gas is filled into the purification cylinder from the buffer tank to fill pressure inside the purification cylinder.

[0013] Furthermore, the gas purification method according to the present invention may be characterized in that a plurality of purification cylinders are provided, and at least one of the plurality of purification cylinders is purified while the other purification cylinders are regenerated in parallel. [Effects of the Invention]

[0014] According to the gas purification apparatus and gas purification method of the present invention, exhaust gas can be efficiently recovered and reused. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram showing the configuration of a gas purification apparatus according to one embodiment to which the present invention is applied. [Figure 2] Figure 1 shows the gas path in the reuse gas recovery process using a gas purification device, as shown in the system diagram. [Figure 3] Figure 1 shows the gas path in the purification cylinder filling process using the gas purification device, as shown in the system diagram.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, a gas purification apparatus and a gas purification method according to an embodiment to which the present invention is applied will be described in detail with reference to the drawings. Note that the drawings used in the following description may show enlarged portions that are characteristic for ease of understanding, and the dimensional ratios of each component are not necessarily the same as those in reality.

[0017] FIG. 1 is a system diagram showing the configuration of a gas purification apparatus 1 according to the present embodiment. The gas purification apparatus 1 of the present embodiment is an example for purifying carbon dioxide gas. The gas purification apparatus 1 of the present embodiment can be applied to, for example, a semiconductor production factory where a large amount of high-purity carbon dioxide gas is used at high and low pressures.

[0018] As shown in FIG. 1, the gas purification apparatus 1 of the present embodiment generally includes two adsorption towers 2A and 2B (purification cylinders), a raw material gas introduction path L1, a product gas discharge path L2, heating means 3A and 3B, a buffer tank 5, a recycled gas supply path L3, and an exhaust path L4.

[0019] The gas purification apparatus 1 of the present embodiment is an apparatus for removing impurities such as total organic carbon and moisture in carbon dioxide gas by the temperature swing adsorption (TSA) method. The gas purification apparatus 1 can be used at a low pressure of less than 1 MPaG or a high pressure of 1 MPaG or more.

[0020] The adsorption towers 2A and 2B are cylindrical adsorption containers having heat resistance and pressure resistance. The shape of the container is not particularly limited.

[0021] Inside the adsorption towers 2A and 2B, an adsorbent is filled to adsorb hydrocarbons and nitrous oxide in the gas. By this adsorbent, total organic carbon and moisture in the gas can be removed. Also, although the adsorption capacity of this adsorbent decreases by adsorbing total organic carbon and moisture, it can desorb total organic carbon and moisture by heating and regenerate the adsorption capacity. The two adsorption towers 2A and 2B are respectively equipped with heating means 3A and 3B.

[0022] The adsorbent is not particularly limited as long as it can remove total organic carbon and moisture in carbon dioxide gas. Specifically, zeolite can be used as the cation. Zeolite is preferable because it has excellent adsorption capacity for total organic carbon and moisture in the gas.

[0023] Although the adsorption capacity of zeolite decreases by adsorbing total organic carbon and moisture, it can desorb total organic carbon and moisture by heating with the heating means 3A and 3B and regenerate the adsorption capacity. As the upper limit value of the heating temperature when regenerating the adsorbent, 300°C is preferable. Since the heating temperature is below the upper limit value, total organic carbon and moisture adsorbed on the adsorbent can be efficiently desorbed, and the activity of the regenerated adsorbent is maintained. When the heating temperature is above the upper limit value, it is not preferable because the power of the heater increases. Also, it causes deterioration of members such as valves.

[0024] At one end side of the first adsorption tower 2A and the second adsorption tower 2B, a first branched raw gas introduction path L1A and a second branched raw gas introduction path L1B branched from the raw gas introduction path L1 are respectively connected. Thereby, the gas before purification (hereinafter sometimes referred to as "raw gas G1") can be supplied to the adsorption towers 2A and 2B via the raw gas introduction path L1. <​Furthermore, product gas outlet L2, which merges from the first branch product gas outlet L2A and the second branch product gas outlet L2B connected to the other ends of the first adsorption tower 2A and the second adsorption tower 2B, respectively, is connected to the other end of each tower. This allows the raw material gas (hereinafter sometimes referred to as "product gas G2") from which all organic carbon and moisture have been removed in the adsorption towers 2A and 2B to be supplied to the outside from the adsorption towers 2A and 2B via the product gas outlet L2.

[0026] The raw material gas introduction paths L1A and L1B are equipped with on / off valves V1A and V1B, respectively. Similarly, the product gas outlet paths L2A and L2B are equipped with on / off valves V2A and V2B, respectively. By operating the open / closed states of the on / off valves V1A, V1B, V2A, and V2B, the raw material gas can be supplied to only one of the first adsorption tower 2A or the second adsorption tower 2B. For example, to supply the raw material gas only to the first adsorption tower 2A, the on / off valves V1A and V2A are opened, and the on / off valves V1B and V2B are closed.

[0027] The exhaust path L4 is connected by confluence from the first branch exhaust path L4A and the second branch exhaust path L4B, which are connected to the other ends of the first adsorption tower 2A and the second adsorption tower 2B, respectively.

[0028] On the first branched raw material gas introduction path L1A, the first branched exhaust path L4A is connected between one end of the first adsorption tower 2A and the on / off valve V1A. Also, on the second raw material gas introduction path L1B, the second branched exhaust path L4B is connected between one end of the second adsorption tower 2B and the on / off valve V1B.

[0029] The exhaust path L4 is formed by connecting the first branch exhaust path L4A and the second branch exhaust path L4B midway. The exhaust path L4 allows exhaust gas generated in the first adsorption tower 2A and the second adsorption tower 2B to be exhausted to the outside. An on / off valve V4 is provided in the exhaust path L4.

[0030] The first branch exhaust path L4A and the second branch exhaust path L4B are equipped with on-off valves V4A and V4B, respectively. By operating the open / closed states of on-off valves V4A and V4B, the generated exhaust gas G4 can be exhausted to the outside. For example, to exhaust the exhaust gas G4 generated in the second adsorption tower 2B to the outside, on-off valve V4B is opened and on-off valve V4A is closed.

[0031] Furthermore, the first branch exhaust path L4A and the second branch exhaust path L4B are provided with air cooling means 4A and 4B, respectively. When exhausting the exhaust gas G4 generated in the adsorption towers 2A and 2B, the air cooling means 4A and 4B can lower the temperature of the exhaust gas G4 as it passes through each branch exhaust path L4A and L4B.

[0032] Furthermore, by operating the open / closed states of the aforementioned on-off valves V1A, V1B, V2A, V2B, V3A, V3B, V4, V4A, and V4B, it is possible to perform a process in one adsorption tower to remove all organic carbon and moisture from the gas (purification process) while simultaneously supplying all organic carbon and moisture adsorbed on the adsorbent from the other adsorption tower to the exhaust path L4 (regeneration process). For example, if purification is performed in the first adsorption tower 2A and regeneration is performed in the second adsorption tower 2B, on-off valves V1A, V2A, V3B, and V4B are opened, and on-off valves V1B, V2B, V3A, and V4A are closed.

[0033] Heating means 3A and 3B are provided in adsorption towers 2A and 2B. Heating means 3A and 3B heat the adsorbent in adsorption towers 2A and 2B, causing all organic carbon and moisture to be desorbed from the adsorbent. The desorbed organic carbon and moisture mix with the recycled gas and are discharged outside the system as exhaust gas. Heating means 3A and 3B heat the recycled gas G3 supplied to adsorption towers 2A and 2B from the buffer tank 5, which will be described later. Therefore, the temperature of the exhaust gas G4 discharged from adsorption towers 2A and 2B after heating and regeneration is high. The exhaust gas G4 passing through the first branch exhaust path L4A and the second branch exhaust path L4B is air-cooled by air-cooling means 4A and 4B and discharged from exhaust path L4.

[0034] The buffer tank 5 is located separately from the gas purification unit 10, which includes two adsorption towers 2A and 2B, a raw material gas introduction path L1, a product gas discharge path L2, heating means 3A and 3B, and an exhaust path L4. In other words, the buffer tank 5 is connected to the gas purification unit 10 via a reused gas supply path L3. The buffer tank 5 is connected to the two adsorption towers 2A and 2B via a reused gas supply path L3 that branches off from the exhaust path L4. A portion of the exhaust gas G4 generated by the adsorption towers 2A and 2B (hereinafter sometimes referred to as "reused gas G3") is filled into the buffer tank 5. The reused gas G3 filled into this buffer tank 5 can be reused. An example of the use of reused gas G3 will be described later. In this embodiment, one buffer tank 5 is provided, but multiple buffer tanks may be provided. Also, the shape and capacity of the buffer tank 5 can be arbitrarily set.

[0035] The recycled gas supply path L3 comprises a first recycled gas supply path L3A, a second recycled gas supply path L3B, and a third recycled gas supply path L3C. The first recycled gas supply path L3A is located at one end (exhaust side) of the adsorption towers 2A and 2B in the buffer tank 5. The second recycled gas supply path L3B is located at the other end (product gas extraction side) of the adsorption towers 2A and 2B in the buffer tank 5. The third recycled gas supply path L3C is located from the buffer tank 5 toward the outside of the system.

[0036] The first recycled gas supply route L3A is connected at one end to the exhaust route L4 and at the other end to the buffer tank 5. The first recycled gas supply route L3A is equipped with an on / off valve V3A. By operating the on / off state of the on / off valve V3A, a portion of the generated exhaust gas G4 (recycled gas G3) can be filled into the buffer tank 5.

[0037] The thick line in Figure 2 shows the gas flow when the gas from the second adsorption tower 2B is introduced into the buffer tank 5 for regeneration. As shown in Figure 2, when a portion of the exhaust gas G4 (reused gas G3) generated in the second adsorption tower 2B is introduced into the buffer tank 5, the exhaust-side on-off valve V4 is closed, and the on-off valves V4B and V3A are opened, allowing the reused gas G3 to flow into the buffer tank 5 through the first reused gas supply path L3A.

[0038] The second reused gas supply route L3B branches at one end into the first branch reused gas supply route L3Ba and the second branch reused gas supply route L3Bb, each of which connects to the first branch product gas outlet route L2A and the second branch product gas outlet route L2B, respectively, while the other end is connected to the buffer tank 5. The second reused gas supply route L3B is equipped with on / off valves V3Ba, V3Bb, V3Bc, V3Bd, and V3Be. By operating the open / closed state of each on / off valve V3Ba, V3Bb, V3Bc, V3Bd, and V3Be, the reused gas G3 filled in the buffer tank 5 can be supplied to the two adsorption towers 2A and 2B.

[0039] The thick line in Figure 3 shows the gas flow when the gas in the buffer tank 5 is introduced into the second adsorption tower 2B to regenerate it and pressurize it. As shown in Figure 3, when supplying the reused gas G3 filled in the buffer tank 5 to the second adsorption tower 2B to pressurize it, the on / off valves V2B and V3Bd are closed, and the on / off valves V3Ba, V3Bb, V3Bc, and V3Be are opened, and the reused gas G3 is pressurized into the second adsorption tower 2B from the second reused gas supply path L3B through the second branch reused gas supply path L3Bb.

[0040] The third recycled gas supply route L3C is connected at one end to the buffer tank 5 and at the other end to a recycling facility outside the system (not shown). The third recycled gas supply route L3C is equipped with an on / off valve V3C. By operating the on / off state of the on / off valve V3C, the recycled gas G3 filled in the buffer tank 5 can be supplied to the recycling facility outside the system. For example, when supplying recycled gas G3 to the recycling facility, the on / off valve V3C is opened. For example, by using the on / off valve V3C as a pressure reducing valve, the recycled gas G3 in the third recycled gas supply route L3C can be reduced to a low pressure, and the low-pressure recycled gas G3 can be used in the above-mentioned recycling facility.

[0041] The gas purification apparatus 1 is designed so that, when regenerating the adsorption towers 2A and 2B, at least a portion of the exhaust gas G4 generated in the adsorption towers 2A and 2B is filled into the buffer tank 5 via the first reuse gas supply path L3A to release pressure inside the adsorption towers 2A and 2B before heating and regeneration, and so that, after heating and regeneration, reuse gas G3 is filled into the adsorption towers 2A and 2B from the buffer tank 5 via the second reuse gas supply path L3B to fill the adsorption towers 2A and 2B to fill pressure inside the adsorption towers 2A and 2B.

[0042] Next, the gas purification method of this embodiment using the gas purification apparatus 1 described above will be explained. The gas purification method of this embodiment includes a raw material gas introduction step of supplying raw material gas G1 to one end of a first adsorption tower 2A and a second adsorption tower 2B; a gas purification step of removing impurities in the supplied raw material gas G1 with one of the adsorption towers (in this case, the first adsorption tower 2A) to purify the gas (product gas G2); a product gas discharge step of dischargeing the purified product gas G2 from the other end of the first adsorption tower 2A; an exhaust step of exhausting exhaust gas G4 generated in the first adsorption tower 2A; and a reuse gas recovery step of recovering at least a portion of the exhaust gas G4 into a buffer tank 5 so that it can be reused as reuse gas G3.

[0043] In other words, the gas purification method of this embodiment involves connecting a first adsorption tower 2A and a second adsorption tower 2B in parallel, performing a purification process to purify the raw material gas G1 in one adsorption tower, and performing a regeneration process to regenerate the adsorbent in the other adsorption tower. By alternately switching the purification process and the regeneration process between the first adsorption tower 2A and the second adsorption tower 2B, the gas can be continuously purified as a whole. In this embodiment, a method in which purification is performed in the first adsorption tower 2A and regeneration is performed in the second adsorption tower 2B will be described as an example.

[0044] First, in the raw material gas introduction process, the raw material gas G1 supplied from the raw material gas introduction path L1 is supplied to the first adsorption tower 2A via the first branch raw material gas introduction path L1A. Specifically, by opening the on / off valve V1A and closing the on / off valves V1B, V2B, V3A, and V4A, the raw material gas G1 can be allowed to flow from the raw material gas introduction path L1 into the first adsorption tower 2A.

[0045] Next, in the gas purification process, the adsorbent in the first adsorption tower 2A removes all organic carbon and moisture from the raw material gas G1 to produce product gas G2. The removed organic carbon and moisture are adsorbed onto the adsorbent. Subsequently, in the product gas discharge process, the purified product gas G2 is supplied to the outside via the first branched product gas discharge route L2A and the product gas discharge route L2. Specifically, the on / off valves V1A and V2A are opened, and the on / off valves V1B, V2B, V3A, and V4B are closed, allowing the product gas G2 purified in the first adsorption tower 2A to flow out to the outside via the first branched product gas outlet path L2A and the product gas outlet path L2.

[0046] Meanwhile, while the product gas G2 is being supplied to the outside from the product gas outlet path L2 in the first adsorption tower 2A, regeneration processing is performed in the second adsorption tower 2B. In the regeneration processing, the reuse gas recovery process and the purification cylinder filling process described above are performed. Specifically, the regeneration processing by the second adsorption tower 2B includes, when regenerating the second adsorption tower 2B, as shown in Figure 2, a reuse gas recovery process in which at least a portion of the exhaust gas G4 generated in the second adsorption tower 2B is recovered in the buffer tank 5 and the pressure inside the second adsorption tower 2B is released, and as shown in Figure 3, a purification cylinder filling process in which reuse gas G3 is filled into the second adsorption tower 2B from the buffer tank 5 and the pressure inside the second adsorption tower 2B is filled.

[0047] In the refining column filling process, before heating and regeneration, a portion of the exhaust gas G4 stored in the buffer tank 5 (recycled gas G3) is supplied to the second adsorption tower 2B via the recycled gas supply path L3. The recycled gas G3 supplied to the second adsorption tower 2B is then heated by the heating means 3B. The heated recycled gas G3 heats the adsorbent in the second adsorption tower 2B to 100-300°C, causing all organic carbon and moisture to be removed from the adsorbent and regenerating the adsorption capacity of the adsorbent. After heating and regeneration, the removed organic carbon and moisture are exhausted to the outside as exhaust gas G4 via the second branch exhaust path L4B and exhaust path L4, and recycled gas G3 is filled into the second adsorption tower 2B from the buffer tank 5 to fill and pressurize the second adsorption tower 2B.

[0048] The specific path for pressurizing is as shown in Figure 3: the on / off valves V2B and V3Bd are closed, and the on / off valves V3Ba, V3Bb, V3Bc, and V3Be are opened. At this time, the recycled gas G3 flowing from the buffer tank 5 to the second adsorption tower 2B is passed through the flow meter F1, thereby gradually increasing the flow rate to pressurize the second adsorption tower 2B.

[0049] Through the above process, purification can be performed in the first adsorption tower 2A and regeneration can be performed in the second adsorption tower 2B. Furthermore, in the regeneration process in the second adsorption tower 2B, by using recycled gas G3, the exhaust gas G4 generated in the first adsorption tower 2A can be reused without being discharged.

[0050] Next, when regenerating the first adsorption tower 2A while gas purification is being performed in the second adsorption tower 2B, the on / off valves V1B, V2B, and V4A are opened, and the on / off valves V1A, V2A, V3A, and V4B are closed. This allows regeneration to be performed in the first adsorption tower 2A and purification to be performed in the second adsorption tower 2B. By switching between gas purification and regeneration in the first adsorption tower 2A and the second adsorption tower 2B in this way, gas can be continuously purified overall.

[0051] Furthermore, the recycled gas G3 recovered and stored in buffer tank 5 can be sent to an external recycling facility (not shown) via the third recycled gas supply route L3C and reused as needed. In this case, the recycled gas G3 in buffer tank 5 can also be kept at a low pressure using a pressure reducing valve.

[0052] The gas purification apparatus 1 configured in this way includes adsorption towers 2A and 2B that remove impurities from the supplied raw material gas G1 to purify the purified gas, a raw material gas introduction path L1 that supplies the raw material gas G1 to one end of the adsorption towers 2A and 2B, a product gas discharge path L2 that discharges the purified gas from the other end of the adsorption towers 2A and 2B, an exhaust path L4 that discharges the exhaust gas G4 generated in the adsorption towers 2A and 2B, a buffer tank 5 that recovers at least a portion of the exhaust gas G4 passing through the exhaust path L4 so that it can be reused as reusable gas, and a reusable gas supply path L3 that connects the adsorption towers 2A and 2B to the buffer tank 5 and allows the reusable gas G3 to flow into the buffer tank 5.

[0053] Furthermore, the gas purification method according to this embodiment includes a raw material gas introduction step of supplying raw material gas G1 to one end of adsorption towers 2A and 2B; a gas purification step of removing impurities in the supplied raw material gas G1 with adsorption towers 2A and 2B to purify the gas; a product gas discharge step of dischargeing the purified gas (product gas G2) from the other end of adsorption towers 2A and 2B; an exhaust step of exhausting exhaust gas G4 generated in adsorption towers 2A and 2B; and a reuse gas recovery step of recovering at least a portion of the exhaust gas G4 into a buffer tank 5 so that it can be reused as reuse gas G3.

[0054] In the gas purification apparatus 1 and gas purification method configured in this way, the gas purification apparatus 1 equipped with a buffer tank 5 can remove all organic carbon and impurities such as water from the raw material gas G1. Furthermore, in this embodiment, at least a portion of the exhaust gas G4 generated in the adsorption towers 2A and 2B can be efficiently recovered and stored in the buffer tank 5 through the reuse gas supply path L3, so that the reuse gas G3 in the buffer tank 5 can be reused. Thus, the purified gas in the adsorption towers 2A and 2B, which was conventionally exhausted as is, can be used as reuse gas G3. For example, although all the exhaust gas generated in the adsorption towers 2A and 2B was exhausted before heating and regeneration of the adsorption towers 2A and 2B, at least a portion of this exhaust gas G4 can be recovered in the buffer tank 5.

[0055] Furthermore, the gas purification apparatus according to this embodiment includes a reused gas supply path L3 which comprises a first reused gas supply path L3A connecting the buffer tank 5 and the exhaust side of the adsorption towers 2A and 2B, and a second reused gas supply path L3B connecting the buffer tank 5 and the purified gas outlet side of the adsorption towers 2A and 2B. When regenerating the adsorption towers 2A and 2B, before heating and regeneration, at least a portion of the exhaust gas G4 generated in the adsorption towers 2A and 2B may be filled into the buffer tank 5 through the first reused gas supply path L3A to release pressure inside the adsorption towers 2A and 2B. After heating and regeneration, reused gas G3 may be filled into the adsorption towers 2A and 2B from the buffer tank 5 through the second reused gas supply path L3B to fill pressure inside the adsorption towers 2A and 2B. Furthermore, in the gas purification method according to this embodiment, when regenerating the adsorption towers 2A and 2B, a reuse gas recovery step is performed before heating and regeneration in which at least a portion of the exhaust gas G4 generated in the adsorption towers 2A and 2B is recovered in the buffer tank 5 and the pressure inside the adsorption towers 2A and 2B is released. After heating and regeneration, a purification cylinder filling step is performed in which reuse gas G3 is filled into the adsorption towers 2A and 2B from the buffer tank 5 and the pressure inside the adsorption towers 2A and 2B is filled.

[0056] Therefore, in this embodiment, during the regeneration process, first, before heating and regeneration, the purified gas (exhaust gas G4) generated in the adsorption towers 2A and 2B can be recovered in the buffer tank 5 via the first reuse gas supply path L3A, and reuse gas G3 can be stored. Furthermore, after heating and regeneration, the reuse gas G3 in the buffer tank 5 can be used to fill the adsorption towers 2A and 2B, thereby enabling the reuse of the purified gas. Thus, in this embodiment, after heating and regeneration, the exhaust gas G4 can be recovered by supplying it to the buffer tank 5, which is maintained at a predetermined internal pressure, without being released into the atmosphere as would occur if exhausted through the exhaust path L4. Additionally, reuse gas G3 can be filled into the adsorption towers 2A and 2B from the buffer tank 5 to fill them and pressurize them. As a result, pressure fluctuations inside the adsorption towers 2A and 2B after thermal regeneration can be mitigated, and the occurrence of condensation and other issues caused by these pressure fluctuations can be suppressed.

[0057] Furthermore, in the gas purification apparatus 1 according to this embodiment, multiple adsorption towers 2A and 2B are provided, and the apparatus is designed so that regeneration processing can be performed in the other adsorption towers 2A and 2B in parallel with the purification process in at least one of the multiple adsorption towers 2A and 2B. Furthermore, in the gas purification method according to this embodiment, multiple adsorption towers 2A and 2B are provided, and while purification processing is performed on at least one of the multiple adsorption towers 2A and 2B, regeneration processing is performed in the other purification towers in parallel.

[0058] Therefore, by arranging two adsorption towers 2A and 2B, and while the first adsorption tower 2A removes impurities at room temperature, the second adsorption tower 2B is heated and regenerated, and by switching between adsorption towers 2A and 2B at regular intervals, purified gas can be continuously supplied and product gas G2 can be extracted.

[0059] Furthermore, in this embodiment, the adsorption towers 2A and 2B are provided with heating means 3A and 3B for heating the recycled gas G3 inside the adsorption towers 2A and 2B. Therefore, the recycled gas G3 supplied to the adsorption towers 2A and 2B during the regeneration process can be efficiently heated by the heating means 3A and 3B.

[0060] Furthermore, in this embodiment, the recycled gas supply route L3 includes a third recycled gas supply route L3C that connects from the buffer tank 5 to an external recycled gas facility. Therefore, the recycled gas G3 stored in the buffer tank 5 can be supplied to the recycled gas facility through the third recycled gas supply route L3C.

[0061] It should be noted that the purification method, or the various shapes and combinations of each component shown in the above-described embodiment, are merely examples and can be modified in various ways based on design requirements, etc., without departing from the spirit of the present invention.

[0062] For example, in the embodiment shown above, carbon dioxide was used as an example of the raw material gas to be purified in the gas purification apparatus 1, but it is not limited to carbon dioxide, and the apparatus can also be applied to the purification of other types of gases such as hydrogen gas and nitrogen gas. [Explanation of Symbols]

[0063] 1. Gas purification apparatus 2A, 2B…Adsorption tower (purification column) 3A, 3B…Heating means 4A, 4B…Air cooling means 5…Buffer Tank 10...Gas purification section L1, L1A, L1B... Raw gas introduction route L2, L2A, L2B... Product gas outlet routes L3, L3A, L3B, L3C... Reusable gas supply routes L4, L4A, L4B... Exhaust path G1... Raw gas G2…Product gas G3…Recycled gas G4... Exhaust gas

Claims

1. A purification cylinder that removes impurities from the supplied raw material gas to purify the gas, A raw material gas introduction path that supplies the raw material gas to one end of the purification cylinder, A product gas discharge path for dischargeing the purified gas from the other end of the purification cylinder, An exhaust path for exhausting the exhaust gas generated in the aforementioned purification cylinder, A buffer tank for recovering at least a portion of the exhaust gas passing through the exhaust path so that it can be reused as recycled gas, A gas purification apparatus comprising a purification cylinder and a buffer tank, and a reuse gas supply path for introducing the reuse gas into the buffer tank.

2. The aforementioned recycled gas supply route is A first recycled gas supply path connects the buffer tank and the exhaust side of the purification cylinder, The system includes a second reuse gas supply path connecting the buffer tank and the purified gas outlet side of the purification cylinder, When the aforementioned refining cylinder is regenerated, Before heating and regeneration, at least a portion of the exhaust gas generated in the purification cylinder is filled into the buffer tank through the first reuse gas supply path, and the purification cylinder is provided to release pressure. The gas purification apparatus according to claim 1, wherein, after heating and regeneration, the reused gas is supplied from the buffer tank to the purification cylinder via the second reused gas supply path, and the inside of the purification cylinder is provided to be pressurized.

3. Multiple refining cylinders are provided. The gas purification apparatus according to claim 2, wherein it is provided that at least one of the plurality of purification cylinders can be purified while the other purification cylinders can be regenerated in parallel.

4. The gas purification apparatus according to claim 2, wherein the purification cylinder is provided with a heating means for heating the recycled gas inside the purification cylinder.

5. The gas purification apparatus according to claim 1 or 2, wherein the reuse gas supply path includes a third reuse gas supply path connected from the buffer tank to an external reuse facility.

6. A raw material gas introduction step in which the raw material gas is supplied to one end of the purification cylinder, A gas purification step in which impurities in the supplied raw material gas are removed in the purification cylinder to purify the purified gas, A product gas discharge step involves dischargeing the purified gas from the other end of the purification cylinder, An exhaust process for exhausting the exhaust gas generated in the aforementioned refining cylinder, A gas purification method comprising a reuse gas recovery step of recovering at least a portion of the exhaust gas into a buffer tank so that it can be reused as reuse gas.

7. When the aforementioned refining cylinder is regenerated, Before heating and regeneration, the reuse gas recovery process is performed, in which at least a portion of the exhaust gas generated in the purification cylinder is recovered in the buffer tank to release pressure inside the purification cylinder. The gas purification method according to claim 6, further comprising a purification cylinder pressure step of filling the purification cylinder with the reused gas from the buffer tank after heating and regeneration to pressurize the inside of the purification cylinder.

8. Multiple refining cylinders are provided. The gas purification method according to claim 7, wherein at least one of the plurality of purification cylinders is purified while the other purification cylinders are regenerated in parallel.

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