Target gas pressure control system, psa device, and target gas pressure control method

Abstract

To appropriately boost the pressure of a target gas to be boosted without using a booster accompanied by large energy consumption such as a compressor.SOLUTION: Provided is a target gas pressure control system, which: includes a temporary storage tank T1 having a storage space SP2 for temporarily storing the received target gas TG, and a blow-out portion PS2a for blowing out the target gas TG in the storage space SP2 to the outside; is provided inside the storage space SP2 of the temporary storage tank T1 with an expanding and contracting bag membrane MF that expands when fluid flows into the bag membrane interior SP1 from the outside and contracts when fluid is discharged from the bag membrane interior SP1, with the bag membrane interior SP1 airtightly partitioned from the storage space SP2; is configured so that the inside SP1 of the bag membrane can be connected in communication with a high-pressure conduit PH through which flows a fluid with a high pressure equal to or higher than the pressure of the target gas TG received in the temporary storage tank T1; and includes a control device that executes an expansion step for communicating the inside SP1 of the membrane with the high-pressure conduit PH in a state in which the target gas TG is present in the storage space SP2.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a target gas pressure control system, a PSA device, and a target gas pressure control method for increasing the pressure of a target gas to a predetermined pressure. [Background technology]

[0002] Recently, there are known plant facilities that produce and supply industrially useful gases (e.g., methane gas) from raw gases such as biogas and coal mine gas by various methods. Among such plant facilities, there is known one equipped with a PSA apparatus as shown in Patent Document 1. The PSA apparatus described in Patent Document 1 shows a process in which the gas to be adsorbed (methane gas) contained in a raw gas (coal mine methane gas) is temporarily pressurized using the PSA method, and the raw gas is pumped into an adsorption tower, where it is adsorbed onto an adsorbent in the adsorption tower. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-169383 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned PSA apparatus, when a gas to be adsorbed is adsorbed by an adsorbent filled in an adsorption tower, the gas to be adsorbed needs to be compressed and pressurized by a compressor or the like that uses electricity, etc., and since the electricity required for compression by the compressor is relatively large, there is room for improvement from the viewpoint of energy saving.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide a target gas pressure control system, a PSA device, and a target gas pressure control method that can appropriately boost the pressure of a target gas to be pressurized without using a booster that involves a large amount of energy consumption, such as a compressor. [Means for solving the problem]

[0006] The gas pressure control system to achieve the above object is as follows: A temporary storage tank including a receiving section for receiving a target gas to be pressurized, a storage space for temporarily storing the received target gas, and a blowing section for blowing the target gas in the storage space to the outside, an expansion / contraction bag membrane that expands when a fluid flows into the bag membrane from the outside and contracts when the fluid is discharged from the bag membrane is provided inside the storage space of the temporary storage tank in a state in which the inside of the bag membrane is airtightly partitioned from the storage space; The inside of the bag membrane is configured to be communicatively connectable to a high-pressure conduit through which the fluid flows at a pressure higher than or equal to the pressure of the target gas received in the temporary storage tank, The device is characterized by including a control device that executes an expansion process for communicating the inside of the bag membrane with the high-pressure conduit while the target gas is present in the storage space.

[0007] A method for controlling a target gas pressure to achieve the above object includes the steps of: A target gas pressure control method for a target gas pressure control system for increasing the pressure of a target gas that is a target to be increased, the method comprising the steps of: The present invention provides a temporary storage tank having a receiving section for receiving the target gas to be pressurized, a storage space for temporarily storing the received target gas, and a blowing section for blowing the target gas in the storage space to the outside, an expansion / contraction bag membrane that expands when a fluid flows into the bag membrane from the outside and contracts when the fluid is discharged from the bag membrane is provided inside the storage space of the temporary storage tank in a state in which the inside of the bag membrane is airtightly partitioned from the storage space; In a target gas pressure control system configured to be able to communicate with a high pressure conduit through which the fluid having a high pressure equal to or higher than the pressure of the storage space flows through the bag membrane, The point is to carry out an expansion step of communicating the inside of the bag membrane with the high-pressure conduit while the target gas is present in the storage space.

[0008] According to the above characteristic configuration, a temporary storage tank is provided with a storage space for temporarily storing a target gas, and an expansion / contraction bag membrane is provided inside the storage space of the temporary storage tank, with the inside of the bag membrane expanding when a fluid flows into the inside of the bag membrane from the outside and contracting when the fluid is discharged from inside the bag membrane, and the inside of the bag membrane is airtightly partitioned from the storage space.By configuring the inside of the bag membrane to be connectable to a high-pressure conduit through which a high-pressure fluid greater than the pressure of the target gas received in the temporary storage tank flows, a high-pressure fluid greater than the pressure of the storage space can be introduced into the inside of the bag membrane, thereby expanding the expansion / contraction bag membrane at high pressure. Furthermore, by the control device executing an expansion process that connects the inside of the bag membrane with the high-pressure conduit while the target gas is present in the storage space, the target gas in the storage space can be compressed and pressurized at high pressure without using a compressor that requires an external power supply, and for example, the pressurized target gas can be blown out from the blowing portion of the temporary storage tank, allowing the pressurized target gas to be efficiently supplied to the outside. As a result, it is possible to realize a target gas pressure control system (target gas pressure control method) that can appropriately boost the pressure of the target gas to be boosted without using a booster that involves a large amount of energy consumption, such as a compressor.

[0009] Further characteristic configurations of the target gas pressure control system include: The inside of the bag membrane is configured to be communicatively connectable to a low-pressure conduit through which the fluid flows at a pressure lower than the pressure of the target gas received in the temporary storage tank, The control device selectively executes a contraction process, which connects the inside of the bag membrane with the low-pressure conduit, alternately with the expansion process while the target gas can flow from the receiving section into the storage space.

[0010] According to the above characteristic configuration, the inside of the bag membrane is configured to be connectable to a low-pressure conduit through which a low-pressure fluid flows that is lower than the pressure of the target gas received in the temporary storage tank. This allows, for example, the control device to realize a contraction process that connects the inside of the bag membrane to the low-pressure conduit while allowing the target gas to flow from the receiving section into the storage space via a check valve or the like, in a highly energy-saving configuration without using a blower or the like that requires an external power supply. Furthermore, because this configuration allows the fluid used to expand the expansion / contraction bag membrane to be guided to the low-pressure pipe in the contraction process, for example, by installing the target gas pressure control system at a location where city gas or the like is used as the fluid and the pressure is reduced from a high-pressure pipe to a low-pressure pipe, it is possible to effectively utilize the pressure energy that has not been used in the past when reducing the pressure of city gas to increase the pressure of the target gas. The city gas used as the fluid for increasing the pressure can be smoothly guided to the gas usage location via the low-pressure pipe, as in the past.

[0011] Further characteristic configurations of the target gas pressure control system include: The control device includes: an adsorption tower which is filled with an adsorbent that adsorbs the gas to be adsorbed contained in the target gas blown out from the blow-out portion of the temporary storage tank, and which has a supply portion to which the target gas is supplied in an adsorption step of adsorbing the gas to be adsorbed to the adsorbent, a separation and discharge portion which separates and discharges to the outside a gas to be separated that is contained in the target gas in the adsorption step and is other than the gas to be adsorbed, and a discharge portion which discharges to the outside the gas to be adsorbed that has been desorbed in a depressurization step of depressurizing the inside of the adsorption tower when the gas to be adsorbed is desorbed from the adsorbent, In one of the adsorption steps, the expansion step is performed at least twice, and the target gas received in the temporary storage tank is guided to the adsorption tower.

[0012] In the target gas pressure control system described above, the target gas can be pressurized without using a compressor or the like that is driven by an external power supply, but the amount of pressurized target gas that can be supplied at one time is limited by the capacity of the temporary storage tank. Therefore, in order to supply the amount of target gas required for one adsorption step to the adsorption tower from the temporary storage tank at one time, it is necessary to prepare a temporary storage tank with a large capacity, which requires a large installation space and increases the initial cost due to the increased equipment construction costs. According to the above characteristic configuration, the control device directs the target gas received in the temporary storage tank to the adsorption tower in a form in which the expansion process is performed at least twice in one adsorption process. Therefore, by adjusting the number of expansion processes performed in one adsorption process according to the amount of target gas required in the adsorption tower in one adsorption process, the amount of target gas required in one adsorption process can be adjusted to an appropriate amount without increasing the capacity of the temporary storage tank.

[0013] Further characteristic configurations of the target gas pressure control system include: The temporary storage tank is configured as a part of a conduit through which the fluid flows.

[0014] According to the above-mentioned characteristic configuration, since the temporary storage tank is constructed from a portion of the piping through which the fluid flows, for example, the temporary storage tank can be buried underground like other high-pressure and low-pressure pipes. Compared to the case of installing a new fluid storage tank above ground, there is no need to secure installation space above ground, and deterioration of the scenery can be prevented. Furthermore, if unused high-pressure pipelines or low-pressure pipeline branches buried underground can be used as temporary storage tanks, it will be possible to reduce initial costs.

[0015] The PSA device to achieve the above objective is: A temporary storage tank including a receiving section for receiving a target gas to be pressurized, a storage space for temporarily storing the received target gas, and a blowing section for blowing the target gas in the storage space to the outside, an expansion / contraction bag membrane that expands when a fluid flows into the bag membrane from the outside and contracts when the fluid is discharged from the bag membrane is provided inside the storage space of the temporary storage tank in a state in which the inside of the bag membrane is airtightly partitioned from the storage space; The inside of the bag membrane is configured to be communicatively connectable to a high-pressure conduit through which the fluid flows at a pressure higher than or equal to the pressure of the storage space, an adsorption tower having an adsorbent filled therein for adsorbing the gas to be adsorbed contained in the target gas blown out from the blow-out portion of the temporary storage tank, a separation and discharge portion for separating and discharging to the outside a gas to be separated other than the gas to be adsorbed that is contained in the target gas in an adsorption step of adsorbing the gas to be adsorbed into the adsorbent, and a discharge portion for discharging to the outside the gas to be adsorbed that is desorbed in a depressurization step of depressurizing the inside when the gas to be adsorbed is desorbed from the adsorbent, This method is characterized by including a control device that performs an expansion process, which connects the inside of the bag membrane with the high-pressure conduit while the target gas is present in the storage space, at least two or more times during one of the adsorption processes.

[0016] According to the above characteristic configuration, in the target gas pressure control system described above, in a PSA apparatus having a configuration in which the pressurized target gas is guided to an adsorption tower, the control device achieves the same effect as when the control device executes the expansion process at least two or more times in one adsorption process. In other words, according to the above-mentioned characteristic configuration, the control device directs the target gas received in the temporary storage tank to the adsorption tower in a form in which the expansion process is performed at least twice in one adsorption process, and by adjusting the number of expansion processes performed in one adsorption process according to the amount of target gas required in the adsorption tower in one adsorption process, the amount of target gas required in one adsorption process can be adjusted to an appropriate amount without increasing the capacity of the temporary storage tank. [Brief description of the drawings]

[0017] [Figure 1]1 is a schematic diagram showing a state in which an expansion / contraction bag membrane is in an expansion process in an adsorption process of a PSA cycle in a PSA device including a target gas pressure control system of the present invention. FIG. [Diagram 2] 1 is a schematic diagram showing a state in which an expansion / contraction bag membrane is in a contraction process in an adsorption process of a PSA cycle in a PSA apparatus including a target gas pressure control system of the present invention. FIG. [Diagram 3] FIG. 2 is a schematic diagram showing a state in which an expansion / contraction bag membrane is in a contraction process during a decompression process of a PSA cycle in a PSA device including a target gas pressure control system of the present invention. [Figure 4] FIG. 1 is a graph showing the change over time in pressure and amount of raw material gas in a temporary storage tank when a decompression step is performed after an adsorption step of a PSA cycle while pressurizing and supplying raw material gas from the target gas pressure control system of the present invention. [Diagram 5] 3 is a control flow when a PSA cycle is executed while pressurizing and supplying a source gas from the target gas pressure control system of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The target gas pressure control system, PSA device, and target gas pressure control method according to the embodiments of the present invention are capable of appropriately pressurizing a target gas to be pressurized without using a booster device that consumes a large amount of energy, such as a compressor. Hereinafter, a target gas pressure control system, a PSA device, and a target gas pressure control method will be described with reference to the drawings. Incidentally, in this embodiment, the pressure of the target gas or the like is shown, but this pressure is an example and is not limited to this value.

[0019] <Target gas pressure control system> As shown in FIGS. 1 to 3, the target gas pressure control system 100 includes a temporary storage tank T1 having a receiving section PS5a that receives a raw material gas TG (an example of a target gas) to be pressurized, a storage space SP2 that temporarily stores the received raw material gas TG, and a blowing section PS2a that blows out the raw material gas TG in the storage space SP2 to the outside. The temporary storage tank T1 expands when a fluid (e.g., city gas 13A) flows into a bag membrane interior SP1 from the outside, and contracts when the fluid is discharged from the bag membrane interior SP1. The bag membrane MF is provided inside the storage space SP2 of the temporary storage tank T1 with the bag membrane interior SP1 airtightly partitioned from the storage space SP2, the bag membrane interior SP1 is configured to be connectable to a high-pressure conduit PH through which a high-pressure fluid received into the temporary storage tank T1 and having a pressure equal to or higher than the pressure of the raw material gas TG flows, and the bag membrane interior SP1 is configured to be connectable to a low-pressure conduit PL through which a low-pressure fluid lower than the pressure of the raw material gas TG received into the temporary storage tank T1 flows, and a control device (not shown) that controls operation is provided.

[0020] To further explain, the receiving section PS5a of the temporary storage tank T1 is connected to a raw material gas supply passage PS5 that supplies the raw material gas TG at a constant pressure (for example, 0.05 MPaG), and the blowing section PS2a is connected to a pressurized gas flow passage PS2 that guides the pressurized raw material gas TG to the supplied section PS2b of the adsorption tower T2 serving as the PSA apparatus 200. The raw material gas supply passage PS5 is provided with a second check valve NV2 that prevents the raw material gas TG from flowing back from the temporary storage tank T1 to the raw material gas supply passage PS5, and the pressurized gas flow passage PS2 is provided with a first check valve NV1 that prevents the raw material gas TG from flowing back from the adsorption tower T2 to the temporary storage tank T1.

[0021] The temporary storage tank T1 is preferably made of steel. The expansion / contraction membrane MF can be made of various materials that can withstand the pressure difference (about 0.4 MPa) between the membrane interior SP1 and the storage space SP2, but a flexible material that maintains its softness over a wide temperature range and maintains its flexibility stably at both low and high temperatures is particularly preferred. For example, nitrile rubber (NBR), which is used as a measuring membrane for medium pressure meters with a pressure resistance of 0.9 MPa, can be suitably used. From the viewpoint of installation space, it is preferable that the volume of the temporary storage tank T1 is small. For example, 3 The volume of the interior SP1 of the expansion / contraction bag membrane MF when expanded can also be set to about the same.

[0022] The high-pressure conduit PH is connected to the bag membrane interior SP1 via a fluid flow passage PS1, and the fluid flow passage PS1 is provided with a first switching valve V1 that can switch the fluid flow passage PS1 between an open state and a closed state. Furthermore, a low-pressure conduit PL is connected to the fluid flow path PS1 between the first switching valve V1 and the bag membrane interior SP1, and the low-pressure conduit PL is provided with a governor G whose opening is adjusted so that the pressure on the secondary side becomes a predetermined target pressure (e.g., 0.002 MPaG). In this embodiment, the pressure of the fluid flowing through the high-pressure conduit PH is 0.65 MPaG, and the supply pressure of the source gas TG is 0.05 MPaG.

[0023] 2, in the control device, when the raw material gas supply passage PS5 is connected to the storage space SP2 of the temporary storage tank T1 and the expansion / contraction bag membrane MF is inflated and the first switching valve V1 is closed, the fluid in the bag membrane interior SP1 of the expansion / contraction bag membrane MF is guided to the low-pressure conduit PL, and a contraction process is executed in which the expansion / contraction bag membrane MF contracts. That is, since the supply pressure of the raw material gas TG is higher than the secondary pressure of the governor G of the low-pressure conduit PL, when the fluid flow passage PS1 is in a communication state with the low-pressure conduit PL, the bag membrane interior SP1 of the expansion / contraction bag membrane MF is compressed by the supply pressure of the raw material gas TG, and a contraction process is realized in which the volume of the bag membrane interior SP1 is reduced. For reference, the supply area downstream of the low-pressure pipeline PL contains, for example, 3 billion m 3 A shipping volume of approximately 1000 tons per year is expected, and in this case, the fluid flowing out from the inside SP1 of the expansion / contraction membrane MF during the contraction process can be recovered sufficiently at all times.

[0024] As shown in FIG. 1, after the contraction process, when the first switching valve V1 is opened in a state where the raw material gas TG exists in the storage space SP2 of the temporary storage tank T1 and the expansion and contraction bag film MF is contracted, the high-pressure fluid flowing through the high-pressure conduit PH is guided to the inside SP1 of the bag film of the expansion and contraction bag film MF, and the expansion process in which the expansion and contraction bag film MF expands is executed. In this expansion process, the raw material gas TG existing in the storage space SP2 of the temporary storage tank T1 is compressed and pressurized as the expansion and contraction bag film MF expands, and the raw material gas TG having a pressure equal to or higher than a certain level is supplied through the pressure-increased gas flow path PS2.

[0025] <PSA device> In the PSA device 200 according to this embodiment, the pressure-increased raw material gas TG blown out from the blowing portion PS2a of the temporary storage tank T1 by the above-described target gas pressure control system 100 is configured to be received in the adsorption process of the PSA cycle by the pressure swing adsorption method (hereinafter sometimes abbreviated as the PSA method). Although detailed description is omitted, the PSA cycle includes an adsorption process of adsorbing the gas to be adsorbed to the adsorbent K inside the adsorption tower T2, a depressurization process of depressurizing the inside of the adsorption tower T2 to expel the gas to be adsorbed adsorbed to the adsorbent K to the outside, a purge process of sweeping out the gas inside the adsorption tower T2, etc., which are executed with different phases among a plurality of adsorption towers T2, so that a highly concentrated gas to be adsorbed can be supplied to the outside. For the sake of easy explanation, the PSA device 200 according to this embodiment is configured such that the pressure-increased raw material gas TG is supplied from the target gas pressure control system 100 to one adsorption tower T2.

[0026] As shown in Figures 1 to 3, the adsorption tower T2 is filled with an adsorbent K that adsorbs the gas to be adsorbed contained in the raw material gas TG blown out from the blow-out section PS2a of the temporary storage tank T1, and has a supply section PS2b to which the raw material gas TG is supplied in an adsorption process in which the gas to be adsorbed is adsorbed into the adsorbent K, a separation and discharge section PS4a that separates and discharges to the outside a gas to be separated other than the gas to be adsorbed that is contained in the target gas in the adsorption process, and a discharge section PS3a that discharges to the outside the desorbed gas to be adsorbed in a depressurization process in which the inside of the adsorbent is depressurized when the gas to be adsorbed is desorbed from the adsorbent K. More specifically, the separation and discharge section PS4a of the adsorption tower T2 is connected to a discharge passage PS4 that discharges the gas to be separated to the outside, and the discharge section PS3a is connected to a discharge passage PS3 that discharges the gas to be adsorbed to the outside. Furthermore, the discharge passage PS4 is provided with a third switching valve V3 that switches the discharge passage PS4 between an open state and a closed state, and the discharge passage PS3 is provided with a second switching valve V2 that switches the discharge passage PS3 between an open state and a closed state.

[0027] In this embodiment, the raw gas TG as the target gas is a gas containing methane and carbon dioxide, and in the PSA apparatus 200 described later, the gas to be separated is methane and the gas to be adsorbed is carbon dioxide. Various adsorbents can be used as the adsorbent K, but CMS (Carbon. Molecular Sieves) can be preferably used.

[0028] The control device closes the second switching valve V2 and opens the third switching valve V3 to receive the raw material gas TG from the supply part PS2b, pressurizes the inside of the adsorption tower T2, and performs an adsorption process in which the adsorption target gas is adsorbed into the adsorbent K. At this time, the separation target gas contained in the raw material gas TG is led to the outside via the discharge flow path PS4. Furthermore, the control device executes a depressurization step of depressurizing the inside of the adsorption tower T2 through the discharge flow path PS3 by opening the second switching valve V2 and closing the third switching valve V3. In this depressurization step, the adsorption target gas adsorbed by the adsorbent K is desorbed and supplied to the outside through the discharge flow path PS3. Although not shown in the drawings, in the depressurization step, the inside of the adsorption tower T2 may be depressurized by a vacuum pump through the discharge flow path PS3.

[0029] In addition, the control device controls the opening and closing of a valve (not shown) to purge the inside of the adsorption tower T2 with a purge gas, thereby executing a purge process and the like; however, detailed explanation of the configuration and control thereof will be omitted here.

[0030] The control device supplies the raw gas TG from the temporary storage tank T1 to the adsorption tower T2 in a form that selectively executes an expansion process and a contraction process alternately. In this embodiment, however, in order to keep the capacity of the temporary storage tank T1 relatively small, the expansion process is executed at least two times in one adsorption process. The process flow will be described below based on the graph in FIG. 4 and the control flow in FIG.

[0031] In the graph of FIG. 4, the period from timing T0 to timing T8 indicates the adsorption step of the PSA cycle, and the period from timing T8 to timing T9 indicates the depressurization step of the PSA cycle. The control device closes the second switching valve V2 and opens the third switching valve V3 during the adsorption process (during execution of steps #01 to #04 in the control flow below), and opens the second switching valve V2 and closes the third switching valve V3 during the depressurization process (during execution of step #05 in the control flow below). The control device executes the adsorption process for about 3 minutes, for example, and executes the depressurization process for about 2 minutes, although this depends on the size of the temporary storage tank T1.

[0032] At the timing T0 shown in Figure 4, when the raw material gas TG is present in the storage space SP2 of the temporary storage tank T1 and the expansion / contraction bag membrane MF is contracting, the control device opens the first switching valve V1 (open / closed state shown in Figure 1) and guides the high-pressure fluid flowing through the high-pressure conduit PH to the inside SP1 of the expansion / contraction bag membrane MF, starting the expansion process in which the expansion / contraction bag membrane MF expands (#01).

[0033] The control device performs the expansion process for a predetermined expansion time (the time from T0 to T1: for example, a time of several tens of seconds), and then immediately switches the first switching valve V1 from an open state to a closed state (the open / closed state shown in Figure 2) to switch to the contraction process (#02).

[0034] Incidentally, after the expansion step is completed, a waiting time may be provided while the raw material gas TG stored in the storage space SP2 is being led to the adsorption tower T2. However, in this embodiment, the waiting time is set to zero from the viewpoint of shortening the time of the adsorption step, taking into consideration that the raw material gas TG is led from the storage space SP2 of the temporary storage tank T1 to the adsorption tower T2 even during the contraction step.

[0035] The control device executes the contraction step over a predetermined contraction time (the period from T1 to T3: for example, a time of about several tens of seconds, which is longer than the expansion time) (#03). In the contraction process, until the pressure inside the temporary storage tank T1 becomes the supply pressure of the raw material gas TG (between T1 and T2), the raw material gas TG stored in the storage space SP2 of the temporary storage tank T1 is guided from the temporary storage tank T1 to the adsorption tower T2, and when the pressure inside the temporary storage tank T1 becomes less than the supply pressure of the raw material gas TG (between T2 and T3), the raw material gas TG flows from the receiving section PS5a of the temporary storage tank T1 into the storage space SP2 of the temporary storage tank T1. On the other hand, in the adsorption tower T2, while the pressure in the temporary storage tank T1 is equal to or higher than the pressure at which the adsorbent K in the adsorption tower T2 can adsorb the target gas, the raw material gas TG flows from the temporary storage tank T1 to the adsorption tower T2, and when the pressure in the temporary storage tank T1 falls below the pressure at which the adsorbent K in the adsorption tower T2 can adsorb the target gas, the flow of the raw material gas TG from the temporary storage tank T1 to the adsorption tower T2 stops. The pressure at which the adsorbent K in the adsorption tower T2 can adsorb the target gas changes depending on the amount of adsorption to the adsorbent K.

[0036] When the number of expansion steps for supplying the amount of raw gas TG necessary to ensure the desired adsorption amount of the adsorbent K in the adsorption tower T2 reaches a predetermined set number (Yes in #04), the control device switches from the expansion step to the contraction step, and starts the depressurization step with the second switching valve V2 in the open state and the third switching valve V3 in the closed state (open / closed state shown in Figure 3), thereby desorbing the adsorption target gas adsorbed by the adsorbent K, and dispensing and recovering it from the dispensing section PS3a (#05). On the other hand, if the number of expansion steps is less than the predetermined number of times (No in #04), the control device repeatedly executes steps #01 to #03.

[0037] [Another embodiment] (1) In the above embodiment, a configuration and control example has been shown in which the raw material gas TG in the storage space SP2 is pumped from the storage space SP2 of the temporary storage tank T1 to the adsorption tower T2 only in the adsorption step of the PSA cycle in the PSA apparatus 200. However, without being limited to this configuration, the raw material gas TG in the storage space SP2 may be controlled to be pumped from the storage space SP2 to the adsorption tower T2 not only in the adsorption step but also, for example, in a pressurization step of pressurizing the adsorption tower T2.

[0038] (2) In the above embodiment, the target gas in the storage space SP2 is only the raw material gas, as the PSA apparatus 200. However, the target gas may be not only the raw material gas, but also the pressurization air used to pressurize the adsorption tower in the pressurization step.

[0039] (3) In the above embodiment, the target gas, which is the raw material gas TG, is a gas containing methane and carbon dioxide. However, various other gases may be used as the target gas.

[0040] (4) In the above embodiment, the fluid flowing into the bag membrane interior SP1 of the expansion / contraction bag membrane MF is city gas 13A. However, the fluid may be any fluid that can expand and contract the bag membrane interior SP1 of the expansion / contraction bag membrane MF, and may be, for example, pressurized air.

[0041] (5) When pressurized air or the like is used as the fluid that expands and contracts the inside SP1 of the bag membrane, a configuration may be adopted in which the fluid flowing out from the inside SP1 of the bag membrane during the contraction process is released into the atmosphere without being guided to the low-pressure conduit PL.

[0042] (6) In the above embodiment, a configuration in which one temporary storage tank T1 is provided has been shown, but a configuration in which a plurality of temporary storage tanks T1 are provided may also be adopted. In this case, it is preferable to execute the expansion step and the contraction step in a plurality of temporary storage tanks T1 in a state where the phases are different from each other.

[0043] (7) In the above embodiment, the adsorption tower T2 may be formed from a part of a conduit through which a fluid flows (for example, the high-pressure conduit PH or the low-pressure conduit PL: not shown). The conduit can be provided as a branch pipe branching off from the high-pressure conduit PH, and can be buried underground, making it suitable for installation in locations with limited installation space.

[0044] (8) In the above embodiment, the waiting time when switching from the expansion process to the adsorption process is set to zero. However, the waiting time may be set to a time greater than zero.

[0045] (9) In the above embodiment, the control device performs control such that the expansion process is performed for a predetermined expansion time and the deflation process is performed for a predetermined deflation time. As another type of control, the control device may determine the start and end timings of the expansion process and the contraction process based on the pressure in the storage space SP2 of the temporary storage tank T1.

[0046] (10) The first check valve NV1 and the second check valve NV2 may be configured as switching valves whose open / closed states can be switched by a control device, and the control device may actively control the open / closed states.

[0047] Furthermore, the configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, provided no contradiction arises. Furthermore, the embodiments disclosed in this specification are merely examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified within the scope that does not deviate from the purpose of the present invention. [Industrial Applicability]

[0048] The target gas pressure control system, PSA device, and target gas pressure control method of the present invention can be effectively used as they are capable of appropriately pressurizing the target gas to be pressurized without using a booster that involves a large amount of energy consumption, such as a compressor. [Explanation of symbols]

[0049] 100: Target gas pressure control system 200:PSA device K: Adsorbent MF: Expansion and contraction bag membrane PH: High pressure pipe PL: Low pressure pipe PS2a:Blowout part PS3a: Payment section PS4a: Separation discharge part PS5a:Reception Department SP1: Inside the pouch membrane SP2: Storage space T1: Temporary storage tank T2: Adsorption tower TG: Raw material gas

Claims

1. A temporary storage tank including a receiving section for receiving a target gas to be pressurized, a storage space for temporarily storing the received target gas, and a blowing section for blowing the target gas in the storage space to the outside, an expansion / contraction bag membrane that expands when a fluid flows into the bag membrane from the outside and contracts when the fluid is discharged from the bag membrane is provided inside the storage space of the temporary storage tank in a state in which the inside of the bag membrane is airtightly partitioned from the storage space; The inside of the bag membrane is configured to be communicatively connectable to a high-pressure conduit through which the fluid flows at a pressure higher than or equal to the pressure of the target gas received in the temporary storage tank, A target gas pressure control system comprising a control device that executes an expansion process to connect the inside of the bag membrane with the high-pressure conduit while the target gas is present in the storage space.

2. The inside of the bag membrane is configured to be communicatively connectable to a low-pressure conduit through which the fluid flows at a pressure lower than the pressure of the target gas received in the temporary storage tank, The target gas pressure control system of claim 1, wherein the control device selectively performs a contraction process, which connects the inside of the bag membrane with the low-pressure conduit, alternately with the expansion process, while the target gas can flow from the receiving section into the storage space.

3. The control device includes: an adsorption tower which is filled with an adsorbent that adsorbs the gas to be adsorbed contained in the target gas blown out from the blow-out portion of the temporary storage tank, and which has a supply portion to which the target gas is supplied in an adsorption step of adsorbing the gas to be adsorbed to the adsorbent, a separation and discharge portion which separates and discharges to the outside a gas to be separated that is contained in the target gas in the adsorption step and is other than the gas to be adsorbed, and a discharge portion which discharges to the outside the gas to be adsorbed that has been desorbed in a depressurization step of depressurizing the inside of the adsorption tower when the gas to be adsorbed is desorbed from the adsorbent, 3. The target gas pressure control system according to claim 1, wherein the expansion step is performed at least twice in one of the adsorption steps, and the target gas received in the temporary storage tank is guided to the adsorption tower.

4. 3. The target gas pressure control system according to claim 1, wherein the temporary storage tank is formed as a part of a conduit through which the fluid flows.

5. A target gas pressure control method for a target gas pressure control system for increasing the pressure of a target gas that is a target to be increased, comprising: The present invention provides a temporary storage tank having a receiving section for receiving the target gas to be pressurized, a storage space for temporarily storing the received target gas, and a blowing section for blowing the target gas in the storage space to the outside, an expansion / contraction bag membrane that expands when a fluid flows into the bag membrane from the outside and contracts when the fluid is discharged from the bag membrane is provided inside the storage space of the temporary storage tank in a state in which the inside of the bag membrane is airtightly partitioned from the storage space; In a target gas pressure control system configured to be able to communicate with a high pressure conduit through which the fluid having a high pressure equal to or higher than the pressure of the storage space flows through the bag membrane, A target gas pressure control method comprising: carrying out an expansion process for connecting the inside of the bag membrane with the high-pressure conduit while the target gas is present in the storage space.

6. A temporary storage tank including a receiving section for receiving a target gas to be pressurized, a storage space for temporarily storing the received target gas, and a blowing section for blowing the target gas in the storage space to the outside, an expansion / contraction bag membrane that expands when a fluid flows into the bag membrane from the outside and contracts when the fluid is discharged from the bag membrane is provided inside the storage space of the temporary storage tank in a state in which the inside of the bag membrane is airtightly partitioned from the storage space; The inside of the bag membrane is configured to be communicatively connectable to a high-pressure conduit through which the fluid flows at a pressure higher than or equal to the pressure of the storage space, an adsorption tower having an adsorbent filled therein for adsorbing the gas to be adsorbed contained in the target gas blown out from the blow-out portion of the temporary storage tank, a separation and discharge portion for separating and discharging to the outside a gas to be separated other than the gas to be adsorbed that is contained in the target gas in an adsorption step of adsorbing the gas to be adsorbed into the adsorbent, and a discharge portion for discharging to the outside the gas to be adsorbed that is desorbed in a depressurization step of depressurizing the inside when the gas to be adsorbed is desorbed from the adsorbent, A PSA apparatus comprising a control device which performs an expansion process for connecting the inside of the bag membrane with the high-pressure conduit while the target gas is present in the storage space at least twice or more in one of the adsorption processes.

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