Gas separation method, gas separation equipment, and gas production method

Abstract

The present invention provides a gas separation control method, gas separation equipment, and gas production method that can maximize the recovery rate of the target gas component. [Solution] The gas separation method according to the present invention is a gas separation method that separates and recovers a target gas component from a raw material gas containing the target gas component by a pressure swing adsorption method, wherein the time t for adsorbing the target gas component onto the adsorbent is determined using the flow rate of the raw material gas, the volume concentration of the target gas component in the raw material gas, the amount of adsorbent, and the adsorption capacity of the adsorbent.

Description

[Technical Field]

[0001] The present invention relates to a gas separation method, a gas separation facility, and a gas production method. [Background technology]

[0002] Conventionally, the pressure swing adsorption method (PSA method) has been used as a method for separating specific gas components contained in raw material gases. The PSA method is a separation method that utilizes the fact that the amount of gas component adsorbed by the adsorbent differs depending on the type of gas and its partial pressure. It has been applied in various fields and is often used as a method to produce high-concentration gases by adsorbing a single component contained in the raw material gas. As a method to improve the separation performance of the PSA method (such as the volume concentration and recovery rate of the target gas component), a method of controlling the temperature of the adsorbent (see Patent Document 1) has been proposed. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 7207626 specification [Overview of the project] [Problems that the invention aims to solve]

[0004] In the PSA method, separation performance, including the recovery rate of specific components, tends to change depending on the cycle time, which corresponds to the time it takes to adsorb and desorb those components. Therefore, if the cycle time is not adjusted to an optimal range, the separation performance will not be maximized, resulting in a problem of inefficient operation.

[0005] Even in the method disclosed in Patent Document 1 mentioned above, when the temperature of the adsorbent is increased, the cycle time may not be optimal for the set temperature depending on the cycle time setting, and the recovery rate does not necessarily increase.

[0006] Furthermore, the optimal cycle time varies depending on the volume concentration of the target gas component contained in the raw gas. If the raw gas changes due to the operating conditions of the upstream equipment, it is necessary to adjust the cycle time to match the volume concentration of the target gas component contained in the raw gas.

[0007] This invention addresses these problems and aims to provide a gas separation method, gas separation equipment, and gas production method that can maximize the recovery rate of the target gas component. [Means for solving the problem]

[0008] The solution to the above problem is as follows:

[0009] 1. A gas separation method for separating and recovering a target gas component from a source gas containing the target gas component by pressure swing adsorption method, A gas separation method in which the time t for adsorbing the target gas component onto the adsorbent is determined using the flow rate of the raw material gas, the volume concentration of the target gas component in the raw material gas, the amount of the adsorbent, and the adsorption capacity of the adsorbent.

[0010] 2. The gas separation method according to item 1 above, wherein the time t for adsorbing the target gas component is within the range of the following formula (1), where tb is the time (s) for the adsorbent to reach its adsorption capacity. 0.27 ≤ t / tb ≤ 0.43 (1) tb = (M × y) / (F × x) (2) Here, Flow rate of the aforementioned raw material gas: F(Nm 3 / s) Volume concentration of the target gas component in the source gas: x(-) Amount of the adsorbent: M (kg) Adsorption capacity of the adsorbent: y(Nm) 3 It is ( / kg).

[0011] 3. The gas separation method according to claim 1 or 2, wherein the adsorption capacity y of the adsorbent is a function of the temperature of the adsorbent.

[0012] 4. The gas separation method according to item 3 above, wherein the adsorption capacity y of the adsorbent is given by the following formula (3). y = -1.7×10 -6 ×T 2 +9.0×10 -5 ×T + 0.034 (3) Here, T (°C) is the temperature of the adsorbent.

[0013] 5. The gas separation method according to any one of items 1 to 4 above, wherein the target gas component is carbon dioxide.

[0014] 6. The gas separation method according to any one of items 1 to 5 above, wherein the raw material gas is blast furnace gas.

[0015] 7. A gas separation facility for separating and recovering a target gas component from a raw material gas containing the target gas component by pressure swing adsorption, comprising: An adsorption tower filled with an adsorbent for adsorbing the target gas component; A raw material gas introduction part for introducing the raw material gas into the adsorption tower; An off-gas discharge part for discharging off-gas containing non-adsorbed gas components not adsorbed by the adsorbent from the adsorption tower; A decompression part for decompressing the inside of the adsorption tower to desorb the raw material gas adsorbed by the adsorbent; A recovery part for recovering the target gas component desorbed by the decompression part; A flow rate measurement part for measuring the flow rate of the raw material gas; A concentration measurement part for measuring the volume concentration of the target gas component in the raw material gas; A control part for controlling the time t for the adsorbent to adsorb the target gas component by using the flow rate of the raw material gas measured by the flow rate measurement part and the volume concentration of the target gas component in the raw material gas measured by the concentration measurement part; The gas separation facility.

[0016] 8. The gas separation facility according to item 7 above, further comprising a pressure relief part having a pressure relief pipe and a valve for discharging gas from the adsorption tower.

[0017] 9. The system further includes a temperature measuring unit for measuring the temperature of the adsorbent, The gas separation apparatus according to 7 or 8, wherein the control unit controls the time t for adsorbing the target gas component onto the adsorbent using the temperature of the adsorbent measured by the temperature measuring unit.

[0018] 10. A gas production method for producing carbon dioxide gas from a raw material gas, using the gas separation method described in any one of items 1 to 6 above, wherein the raw material gas is a gas containing carbon dioxide and the target gas component is carbon dioxide.

[0019] 11. A gas production method for producing hydrogen gas from a raw material gas, using the gas separation method described in any one of items 1 to 4 and 6 above, wherein the raw material gas is a gas containing hydrogen and the target gas component is an impurity component other than hydrogen. [Effects of the Invention]

[0020] According to the present invention, the recovery rate of the target gas component can be maximized. [Brief explanation of the drawing]

[0021] [Figure 1] This figure shows an example of a gas separation facility according to the present invention. [Figure 2] This figure shows the relationship between the ratio t / tb (the time t required for the adsorbent to adsorb the target gas component (carbon dioxide)) to the time tb required for the adsorbent to reach its adsorption capacity, and the recovery rate of the target gas component (carbon dioxide). [Modes for carrying out the invention]

[0022] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 shows an example of a gas separation facility according to the present invention. The gas separation facility 1 shown in Figure 1 is a facility that separates and recovers a gas containing a target gas component (for example, carbon dioxide) from a raw material gas by a pressure swing adsorption method, and comprises two adsorption towers 2 filled with an adsorbent that adsorbs the target gas component, a raw material gas introduction section 3 for introducing the raw material gas into the adsorption towers 2, and an off-gas discharge section 4 for discharging off-gas containing non-adsorbed gas components that were not adsorbed by the adsorbent from the adsorption towers 2. Note that the gas separation facility 1 does not have a cleaning gas supply pipe that supplies a portion of the target gas discharged from the other adsorption tower 2 as cleaning gas to the adsorption tower 2.

[0023] The raw material gas introduction section 3 includes a raw material gas supply pipe L1 for introducing the raw material gas into the adsorption tower 2 during the adsorption process, and a valve V1 for controlling the flow of the raw material gas in the raw material gas supply pipe L1. The raw material gas supply pipe L1 is also equipped with a raw material gas flow meter (flow rate measuring section) 9 for measuring the flow rate of the raw material gas, and a raw material gas concentration meter (concentration measuring section) 10 for measuring the volume concentration of the target gas component in the raw material gas.

[0024] The off-gas discharge section 4 includes an off-gas discharge pipe L2 and a valve V2, and discharges off-gas containing non-adsorbed gas components that were not adsorbed by the adsorbent when the raw material gas is introduced into the adsorption tower 2 during the adsorption process.

[0025] Furthermore, the gas separation equipment 1 includes a pressure reduction unit 5, a recovery unit 6, and a control unit 7. The pressure reduction unit 5 has a vacuum pump VP that sucks gas from inside the adsorption tower 2 to reduce the pressure, a vacuum pump intake pipe L3 from the adsorption tower 2 to the vacuum pump VP, and a valve V3, and reduces the pressure inside the adsorption tower 2 in order to desorb the target gas components adsorbed on the adsorbent.

[0026] The recovery unit 6 has a valve V4 on the discharge side of the vacuum pump VP that switches between desorption of the target gas component and desorption of other gas components, and a gas recovery pipe L4, and recovers the target gas containing the target gas component desorbed in the depressurization unit 5, as well as gas containing gas components other than the target gas component.

[0027] The control unit 7 controls the time t for adsorbing the target gas component onto the adsorbent, using the flow rate of the raw material gas, the volume concentration of the target gas component in the raw material gas, the amount of adsorbent, and the time tb for reaching the adsorption capacity calculated from the adsorption capacity of the adsorbent. The control unit 7 is connected to a raw material gas flow meter 9 and a raw material gas concentration meter 10 that measures the volume concentration of the target gas component in the raw material gas. The control unit 7 is configured to receive data on the flow rate of the raw material gas measured by the raw material gas flow meter and data on the volume concentration of the target gas component in the raw material gas measured by the raw material gas concentration meter 10.

[0028] The above-mentioned "time t for adsorbing the target gas component onto the adsorbent" refers to the time of the adsorption process, in which raw material gas is introduced into the adsorption tower 2, the target gas component contained in the raw material gas is adsorbed onto the adsorbent, and the gas containing gas components that were not adsorbed onto the adsorbent is discharged as off-gas. It does not include the time of the pressurization process for increasing the pressurization inside the adsorption tower 2.

[0029] Furthermore, as shown in Figure 1, it is preferable that the gas separation equipment 1 includes a pressure relief section 8 in the adsorption tower 2, which has a pressure relief pipe L5 and a pressure relief valve V5 for reducing the pressure inside the adsorption tower 2. This allows for a pressure relief process to be performed in which the pressure relief valve V5 is opened to reduce the pressure inside the adsorption tower 2 before the pressure inside the adsorption tower 2 is reduced by the vacuum pump VP of the depressurization section 5 during the desorption process.

[0030] In PSA operation, the raw material gas is often supplied to the adsorption tower 2 under pressurized conditions during the adsorption process. Therefore, at the start of the desorption process, impurity gas components can be desorbed from the adsorbent by pressure release alone and discharged as pressure-released gas, which is the impurity gas. Accordingly, as shown in the lower part of the adsorption tower 2 in Figure 1, the power consumption of the vacuum pump VP can be reduced by connecting a pressure-release pipe L5, which is a gas line that does not pass through the vacuum pump VP, to the adsorption tower 2 to recover the impurity gas. The pressure-release pipe L5 can also be connected to the gas recovery piping L4 downstream of the vacuum pump VP (piping that recovers gases containing gas components other than the target gas component) without going through the vacuum pump VP.

[0031] Furthermore, since the adsorption capacity of the adsorbent changes somewhat with temperature, it is preferable to provide a temperature measuring unit 11 for measuring the temperature of the adsorbent. It is preferable to provide the temperature measuring unit 11 inside the adsorbent packed bed to measure the temperature of the adsorbent. Also, when the raw material gas is heated and the adsorbent is heated by the sensible heat of the raw material gas, the temperatures of the raw material gas and the adsorbent become approximately the same. Therefore, in an adsorption tower where it is known that the temperature of the raw material gas and the temperature of the adsorbent are approximately the same, instead of directly measuring the temperature of the adsorbent, the temperature measuring unit 11 can be configured to measure the temperature of the raw material gas in the raw material gas introduction unit 3 (for example, the raw material gas supply pipe L1) (i.e., the temperature measuring unit 11 can be configured as a raw material gas thermometer), and the measured temperature of the raw material gas can be used as the temperature of the adsorbent. The temperature measuring unit 11 can be configured as, for example, a thermometer.

[0032] Furthermore, if the temperature dependence of the adsorption capacity of the adsorbent is given by a mathematical formula, it is preferable to store the formula describing the temperature dependence of the adsorption capacity in the control unit 7, provide the temperature data of the adsorbent to the control unit 7, and use the provided temperature data of the adsorbent to control the time t for adsorbing the target gas component onto the adsorbent. This makes it possible to determine an appropriate adsorption time t for any given operating temperature.

[0033] Next, the operation of the gas separation equipment 1 will be explained. The operation of the gas separation equipment 1 consists of four processes, for example: a pressurization process, an adsorption process, a depressurization process, and a desorption process. When one of the two adsorption towers 2 is performing the adsorption process, the other adsorption tower 2 is performing the desorption process, and then the two processes are switched and the equipment operates in reverse.

[0034] The pressurization step is the process of increasing the pressure of the adsorption tower 2 to a certain pressure, and the adsorption step is the process of mainly adsorbing the target gas components onto the adsorbent in the adsorption tower 2. The depressurization step is the process of reducing the pressure inside the adsorption tower 2 before transitioning from the adsorption step to the desorption step, and the desorption step is the process of reducing the pressure inside the adsorption tower 2 in the depressurization section 5 and desorbing the target gas components adsorbed onto the adsorbent in the adsorption tower 2 from the adsorbent. Then, during the desorption step, the valve V4 of the recovery section 6 on the discharge side of the vacuum pump VP is switched to separate the target gas components from other gas components.

[0035] The duration of the adsorption process (adsorption time t) is preferably set to maximize adsorption efficiency. When operating the gas separation equipment 1 as described above, the optimal conditions, such as the adsorption time of the target gas component onto the adsorbent in the adsorption tower 2, vary depending on the flow rate of the raw material gas, the volume concentration of the target gas component in the raw material gas, and the type of adsorbent. Therefore, if the raw material gas changes due to the operating conditions of the upstream equipment, it is necessary to adjust the adsorption time onto the adsorbent according to the amount of the target gas component in the raw material gas.

[0036] Based on diligent research conducted by the inventors using laboratory experimental results of different scales, they discovered that even when the apparatus size and gas conditions differ, an appropriate adsorption time t can be set regardless of the apparatus scale or gas conditions by non-dimensionalizing the ratio t / tb, which is obtained by dividing the time t for adsorption of the target gas component by the time tb for reaching the adsorption capacity. Here, the time tb for reaching the adsorption capacity is the time required to fill all the adsorption sites of the adsorbent, assuming that all of the target gas component in the raw material gas introduced into the adsorption tower 2 is adsorbed. The time tb for reaching the adsorption capacity is calculated by the flow rate F(Nm³) of the raw material gas. 3 (v / s), volume concentration x (dimensionless) of the target gas component (= (v / v)), amount of adsorbent M (kg), adsorption capacity y (Nm³) of the adsorbent 3 It can be calculated using the value of ( / kg). Specifically, it is shown in the following equation (2). tb = (M × y) / (F × x) (2) Here, the time tb to reach adsorption capacity is determined by the number of moles of the target gas component flowing into adsorption tower 2. Therefore, the flow rate F of the raw material gas is proportional to the molar flow rate, calculated at 0°C and 1 atmosphere (Nm³). 3 The adsorption capacity y of the adsorbent changes with temperature, so the value of the adsorption capacity at the adsorbent temperature during the adsorption process is used.

[0037] If the target gas component were adsorbed across the entire adsorbent at an infinitely fast rate, then setting the adsorption time so that t / tb is 1 should maximize the adsorption efficiency. However, in reality, adsorption of gas components onto an adsorbent occurs through both adsorption onto the adsorbent surface and diffusion into the adsorbent's interior. Adsorption onto the adsorbent surface tends to be faster, while diffusion into the adsorbent's interior tends to be slower. Therefore, immediately after the start of adsorption, the target gas component is adsorbed at the adsorption sites on the adsorbent surface, where the adsorption rate is high, resulting in high adsorption efficiency. However, as time passes after the start of adsorption, the number of adsorption sites on the adsorbent surface decreases, and diffusion into the adsorbent becomes the rate-limiting factor, thus reducing the adsorption efficiency. As a result, in the actual adsorption tower 2, the t / tb that yields maximum adsorption efficiency is less than 1.

[0038] The inventors have found that the recovery rate of the target gas component can be maximized by determining the time t for adsorbing the target gas component onto the adsorbent, based on the amount of the target gas component in the raw gas measured by the raw gas flow meter 9 and the raw gas concentration meter 10, such that the ratio t / tb, which is the ratio of t to the time tb for the adsorbent to reach its adsorption capacity, is between 0.27 and 0.43.

[0039] That is, when t / tb is less than 0.27, the adsorption time t is short and the ratio of the raw material gas supply amount to the filled adsorbent is small. Therefore, among the filled adsorbents, the target gas component is adsorbed only on the upstream adsorbent on the raw material gas introduction side, and the adsorption efficiency decreases. On the other hand, when t / tb exceeds 0.43, as described above, the adsorption rate decreases as time elapses from the start of adsorption. Therefore, the target gas component does not adsorb sufficiently and flows out as off-gas, and the adsorption efficiency decreases. Thus, in the present invention, t / tb is set to be 0.27 or more and 0.43 or less. That is, t / tb satisfies the following formula (1). 0.27 ≦ t / tb ≦ 0.43 (1)

[0040] Note that the adsorption capacity y varies depending on the temperature T (°C) of the adsorbent in the adsorption process. That is, since the adsorption capacity y of the adsorbent is a function of the temperature of the adsorbent, by formulating the dependence of the adsorption capacity y (Nm 3 / kg) on the temperature T (°C), it becomes possible to determine the appropriate adsorption time t without measuring the adsorption capacity y every time the operating temperature is changed, which is preferable.

[0041] Specifically, when formulating the relationship between the adsorption capacity y (Nm 3 / kg) of 13X zeolite and the temperature T (°C), y = -1.7×10 -6 ×T 2 +9.0×10 -5 ×T + 0.034 (3) When this formula (3) is substituted into formula (2), the adsorption capacity reach time tb is given by the following formula (4). tb = {M×(-1.7×10 -6 ×T 2 +9.0×10 -5 ×T + 0.034)} / (F×x) (4)

[0042] As is clear from formula (4), without measuring the adsorption capacity y of the adsorbent every time the operating temperature is changed, the flow rate F (Nm 3The appropriate adsorption time t can be determined solely from the volume concentration x (dimensionless) (= (v / v)) of the target gas component, the amount of adsorbent M (kg), and the temperature T (°C) of the adsorbent. Furthermore, since the temperature T (°C) of the adsorbent in the adsorption process may vary slightly depending on the operating environment, it is preferable to use the temperature T (°C) of the adsorbent measured at the end of the adsorption process of the previous cycle to calculate the adsorption capacity y and determine the appropriate adsorption time t.

[0043] The present invention is applicable to any PSA-type gas separation equipment. Using the gas separation method according to the present invention, carbon dioxide gas or hydrogen gas can be produced. For example, carbon dioxide can be used as the target gas component and separated from a raw material gas. The raw material gas can be by-product gas discharged from a steel mill. For example, carbon dioxide can be used as the raw material gas, such as blast furnace gas, and carbon dioxide as the target gas component, allowing carbon dioxide to be separated from the blast furnace gas. Alternatively, for example, hydrogen can be used as the raw material gas, such as coke oven gas, and other impurity components can be used as the target gas component, allowing hydrogen to be separated from the coke oven gas by removing the impurity components. Therefore, by using the gas separation method of the present invention, carbon dioxide gas with a higher carbon dioxide concentration and hydrogen gas with a higher hydrogen concentration can be produced from a raw material gas.

[0044] As is clear from the above description, the present invention is characterized by a method for determining the time t for adsorbing a target gas component onto an adsorbent in the adsorption process. Other conditions are not limited as long as they do not impair the effects of the invention and can be appropriately configured. [Examples]

[0045] To confirm the effects of the present invention, adsorption tests were conducted using two types of test equipment: a small laboratory test apparatus and a large bench test apparatus. The raw material gas had a gas composition simulating blast furnace gas, and the target gas component was carbon dioxide. The adsorbent was 13X zeolite (particle size 1.5 mm). The carbon dioxide adsorption capacity of 13X zeolite changed with temperature, and the adsorption capacity per 1 kg of adsorbent was 0.035 Nm³ at 25°C. 3 -Carbon dioxide / kg, 0.034 Nm³ at 55°C 3 -Carbon dioxide / kg, 0.029 Nm³ at 85°C 3 -Carbon dioxide / kg. In this laboratory test apparatus, it has been confirmed that the temperature of the adsorbent is the same as the gas temperature, so the adsorption capacity of the adsorbent was calculated using the temperature of the raw material gas measured in the raw material gas introduction section 3.

[0046] [Laboratory testing equipment] The configuration of the laboratory test apparatus and experimental conditions are as follows. Details of the experiment and experimental results are shown in Table 1. Adsorbent amount: 0.19 kg Raw material gas: A mixed gas intended to simulate blast furnace gas. Flow rate of raw material gas: 0.32 Nm³ 3 / h, CO2 concentration of raw material gas: 22% by volume, raw material gas temperature: 25~85°C (at the end of the adsorption process) Pressure inside the adsorption tower during the adsorption process: 151 kPa Pressure inside the adsorption tower during the desorption process: 6 kPa Carbon dioxide capture purity: 89.5-96.8% by volume Adsorption time t:87.5~147.5s

[0047] [Table 1]

[0048] [Bench testing equipment] The configuration of the bench test apparatus and the experimental conditions are as follows: Adsorbent quantity: 260 kg Raw material gas: Blast furnace gas Flow rate of raw material gas: 440 Nm 3 / h, CO2 concentration of source gas: 23.8~26.1% by volume, source gas temperature: 25℃ Pressure inside the adsorption tower during the adsorption process: 151 kPa Pressure inside the adsorption tower during the desorption process: 6 kPa Carbon dioxide capture purity: 89.6-95.1% by volume Adsorption time t: 104~125s

[0049] Figure 2 shows the relationship between t / tb and the recovery rate of the target gas component. t / tb is the ratio of the time t for adsorbing the target gas component (carbon dioxide) onto the adsorbent to the time tb for the adsorbent to reach its adsorption capacity. Figure 2 plots the data obtained from the laboratory and bench testing apparatus described above. As is clear from Figure 2, a higher recovery rate is achieved when t / tb is between 0.27 and 0.43 compared to cases where t / tb is outside this range, indicating that the recovery rate of the target gas component, carbon dioxide, can be maximized. [Industrial applicability]

[0050] According to the present invention, the recovery rate of the target gas component can be maximized. [Explanation of Symbols]

[0051] 1. Gas separation equipment 2 Adsorption tower 3. Introduction 4. Off-gas discharge section 5. Reduced pressure section 6. Recovery section 7 Control Unit 8. Pressure relief section 9. Raw material gas flow meter (flow measurement unit) 10. Raw material gas concentration meter (concentration measurement unit) 11. Raw material gas thermometer (temperature measuring section) L1 Raw Gas Supply Piping L2 Off-gas discharge piping L3 Vacuum pump intake piping L4 Gas Recovery Piping L5 pressure relief pipe V1, V2, V3, V4 valves V5 pressure relief valve VP Vacuum Pump

Claims

1. A gas separation method for separating and recovering a target gas component from a source gas containing the target gas component by pressure swing adsorption method, A gas separation method in which the time t for adsorbing the target gas component onto the adsorbent is determined using the flow rate of the raw material gas, the volume concentration of the target gas component in the raw material gas, the amount of the adsorbent, and the adsorption capacity of the adsorbent.

2. The gas separation method according to claim 1, wherein the time t for adsorbing the target gas component is within the range of the following formula (1), where tb is the time (s) for the adsorbent to reach its adsorption capacity. 0.27 ≦ t / tb ≦ 0.43 (1) tb=(M×y) / (F×x) (2) Here, Flow rate of the aforementioned raw material gas: F (Nm ３ / s) Volume concentration of the target gas component in the source gas: x(-) Amount of the adsorbent: M (kg) Adsorption capacity of the adsorbent: y (Nm) ３ It is ( / kg).

3. The gas separation method according to claim 1 or 2, wherein the adsorption capacity y of the adsorbent is a function of the temperature of the adsorbent.

4. The gas separation method according to claim 3, wherein the adsorption capacity y of the adsorbent is given by the following formula (3). y=-1.7×10 －６ xT ２ +9.0×10 －５ ×T+0.034 (3) Here, the temperature of the adsorbent is T (°C).

5. The gas separation method according to claim 1 or 2, wherein the target gas component is carbon dioxide.

6. The gas separation method according to claim 1 or 2, wherein the raw material gas is blast furnace gas.

7. A gas separation apparatus for separating and recovering a target gas component from a source gas containing the target gas component by pressure swing adsorption method, An adsorption tower filled with an adsorbent that adsorbs the aforementioned target gas component, A raw material gas introduction unit for introducing the raw material gas into the adsorption tower, An off-gas discharge section discharges off-gas containing non-adsorbed gas components that were not adsorbed by the adsorbent from the adsorption tower, A depressurization section for reducing the pressure inside the adsorption tower in order to desorb the raw material gas adsorbed on the adsorbent, A recovery unit for recovering the target gas component desorbed in the aforementioned depressurization unit, A flow rate measuring unit for measuring the flow rate of the aforementioned raw material gas, A concentration measuring unit for measuring the volume concentration of the target gas component in the raw material gas, A control unit controls the time t for adsorbing the target gas component onto the adsorbent, using the flow rate of the raw material gas measured by the flow rate measuring unit and the volume concentration of the target gas component in the raw material gas measured by the concentration measuring unit. A gas separation facility equipped with the following features.

8. The gas separation apparatus according to claim 7, further comprising a pressure relief section having a pressure relief pipe and a valve for releasing gas from the adsorption tower.

9. The system further includes a temperature measuring unit for measuring the temperature of the adsorbent, The gas separation apparatus according to claim 7 or 8, wherein the control unit controls the time t for adsorbing the target gas component onto the adsorbent using the temperature of the adsorbent measured by the temperature measuring unit.

10. A gas production method comprising using the gas separation method described in claim 1 or 2, wherein the raw material gas is a gas containing carbon dioxide and the target gas component is carbon dioxide, and carbon dioxide gas is produced from the raw material gas.

11. A gas production method comprising producing hydrogen gas from a raw material gas using the gas separation method described in claim 1 or 2, wherein the raw material gas is a gas containing hydrogen and the target gas component is an impurity component other than hydrogen.

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