Adsorptive separation method

Abstract

An adsorptive separation method is disclosed. The adsorptive separation method, of the present invention, for adsorbing and separating a first gas from a mixed gas by using a plurality of adsorption beds having an adsorbent that selectively adsorbs the first gas comprises an adsorption step, a decompression step, a first rinse step, a second rinse step, a decompression desorption step, a purge step, a pressurization step, a pressure-equalizing pressurization step, and an accumulation step. Provided is the adsorptive separation method, according to the present invention, by which, in the second rinse step, the high-purity first gas is injected at a first pressure into the adsorption bed and, in the decompression desorption step, the first gas is compressed to the first pressure by a compressor in a process of transferring the gas to a high-pressure product container, such that a product gas of atmospheric pressure or higher discharged in a blowdown step is pressurized to the pressure at which rinsing is performed, thereby reducing power consumption, and reducing the consumption of power used to form a recirculation stream used for rinsing.

Description

Adsorption separation method

[0001] The present invention relates to an adsorption separation method, and more specifically, to an adsorption separation method configured to adsorb and separate a specific gas from a mixed gas.

[0002] Steam Methane Reforming (SMR) produces reformed gas containing H2, CO, N2, and CH4 by chemically reacting methane gas contained in natural gas with steam through a catalyst at a certain pressure under the action of high temperature (700–1,000°C). The reformed gas is fed into a Water Gas Shift (WGS) reactor, where CO is converted into H2 and CO2.

[0003] Pressure Swing Adsorption (PSA) adsorbs N2, CO, CH4, and CO2, and extracts high-purity hydrogen products through pressure increase.

[0004] When a CO2VPSA (Vacuum Pressure Swing Adsorption) device is installed between the SMR+WGS reactor and the H2PSA device, the CO2VPSA device extracts CO2, increasing the H2 partial pressure of the H2PSA feed stream and increasing the H2 recovery rate.

[0005] In this regard, U.S. Register No. 8709136 (hereinafter referred to as the 'prior art') discloses an adsorption process.

[0006] The adsorption process of the prior art is a process for separating a first gas (CO2) from a feed gas mixture including the first gas and a second gas (H2), and uses five or more adsorption beds containing a selective adsorbent for the first gas.

[0007] This process exposes each adsorption bed to a cycle repeated in the order of (a) a feeding step, (b) a pressure reduction equalization step, (c) an additional pressure reduction step, (d) a blowdown step, (e) a purge step, (f) a rinse step, (g) a pressure increase equalization step, and (h) a repressurization step.

[0008] The adsorption process of the prior art initiates a process of producing high-purity CO2 by reducing the pressure to a vacuum during the blowdown step and storing the CO2 product in a CO2 product tank. At this time, if the component to be separated is a highly adsorbent component, a rinse step must be performed to recirculate the heavy component obtained as a product in order to achieve high purity of the component.

[0009] [Prior Art Literature]

[0010] [Patent Literature]

[0011] U.S. Registered Publication No. 8709136 (Registration Date: April 29, 2014)

[0012] The objective of the present invention is to provide an adsorption separation method that reduces power consumption by pressurizing the product gas discharged at the blowdown stage to a pressure higher than atmospheric pressure to the pressure at which rinsing is performed, and reduces the power consumption used to create the recirculation stream used for rinsing.

[0013] The above objective is achieved, according to the present invention, by a method for separating a first gas from a mixed gas by adsorbing it using a plurality of adsorption beds equipped with an adsorbent that selectively adsorbs a first gas, comprising: an adsorption step of supplying a mixed gas to the adsorption beds so that the adsorption beds adsorb the first gas and discharge a second gas separated from the first gas; a depressurization step of depressurizing the adsorption beds after the adsorption step is completed to discharge the second gas present in the empty space of the adsorption beds and concentrate the first gas; a first rinse step of transferring exhaust gas having a higher concentration of the first gas than the mixed gas to the adsorption beds after the depressurization step is completed to remove gas components other than the first gas; a second rinse step of transferring high-purity first gas from a high-pressure product container to the adsorption beds after the first rinse step is completed to remove gas components other than the first gas; and a depressurization desorption step of depressurizing and transferring the first gas adsorbed on the adsorption beds after the second rinse step is completed to the high-pressure product container. A low-pressure cleaning step (purging step) for transferring gas from an intermediate storage tank storing a portion of the gas discharged in the above-mentioned depressurization step to an adsorption bed where the above-mentioned depressurization step is completed, and further desorbing the first gas adsorbed on the adsorption bed where the depressurization step is completed; a first partial pressurization step for transferring a portion of the gas from the intermediate storage tank storing the gas discharged in the above-mentioned depressurization step, the first rinse, and the exhaust gas discharged in the above-mentioned second rinse step to the adsorption bed where the above-mentioned depressurization step is completed, and pressurizing; and a pressure equalization pressurization step for transferring a portion of the exhaust gas obtained in the above-mentioned depressurization step to the adsorption bed where the first partial pressurization is completed and pressurizing the pressure equalization.This is achieved by an adsorption separation method comprising: a pressurization step in which a high-concentration first gas from an intermediate storage tank is transferred through a compressor to an adsorption bed in which the above-mentioned equalization pressurization is completed, thereby pressurizing an adsorption tower in which the first equalization pressurization step is completed; wherein, in the second rinsing step, the high-purity first gas is introduced into the adsorption bed at a first pressure, and in the depressurization desorption step, the first gas is introduced into a compressor while maintaining the pressure at the time of depressurization, compressed to a pressure greater than the first pressure, and transferred to a high-pressure product container.

[0014] The plurality of adsorption beds includes a first adsorption bed, a second adsorption bed, a third adsorption bed, a fourth adsorption bed, and a fifth adsorption bed, and the first adsorption bed, the second adsorption bed, the third adsorption bed, the fourth adsorption bed, and the fifth adsorption bed may each be configured to periodically adsorb and separate a first gas from a mixed gas.

[0015] The above pressure reduction step may comprise: a pressure equalization reduction step in which the adsorption bed in which the adsorption step is completed is connected to the adsorption bed in which the first partial pressurization is completed and the pressure of the adsorption bed in which the adsorption step is completed is reduced until the pressure becomes equal; and a first parallel pressure reduction step in which the adsorption bed in which the first pressure equalization reduction step is completed is additionally reduced.

[0016] When the low-pressure washing step is performed in the adsorption bed where the above-mentioned depressurization step is completed, the exhaust gas from the low-pressure washing step can be compressed through a compressor and transferred to the adsorption bed where the above-mentioned depressurization step is completed so as to be used in the first rinsing step.

[0017] The gas components discharged in the first rinse step and the second rinse step may be transferred to the intermediate storage tank, some of which are introduced into the adsorption bed in the low-pressure cleaning step to be used for performing the low-pressure cleaning step, and some of which are compressed through a compressor and transferred to the adsorption bed where pressure equalization is completed to be used for accumulating pressure in the adsorption bed where pressure equalization is completed.

[0018] Some of the gas stored in the above intermediate storage can be transferred to the above low-pressure washing step and utilized for low-pressure washing or for pressurizing the adsorption bed after the equalization pressurization is completed, or it can be used as fuel to supply reaction heat for the methane steam reforming reaction process.

[0019] The above method may include a step of further accumulating pressure to the pressure at which the adsorption step is performed by utilizing a portion of the high-concentration second gas discharged from the adsorption bed where the adsorption step is in progress, in the adsorption bed where the above-mentioned accumulation is completed.

[0020] The above pressure reduction step comprises: a first equalization pressure reduction step for reducing the pressure of the adsorption bed for which the adsorption step has been completed by connecting the adsorption bed for which the adsorption step has been completed with the adsorption bed for which the second equalization pressure pressurization has been completed so that the pressures of the two towers become equal; a cleaning supply step for reducing the pressure of the adsorption bed for which the first equalization pressure reduction has been completed by connecting the adsorption bed for which the first equalization pressure reduction has been completed with the adsorption bed for which the pressure desorption has been completed, while supplying gas for low-pressure cleaning of the adsorption bed for which the pressure desorption has been completed; and a second equalization pressure reduction step for reducing the pressure of the adsorption bed for which the cleaning supply step has been completed by connecting the adsorption bed for which the cleaning supply step has been completed with the adsorption bed for which the first partial pressurization has been completed so that the pressures of the two towers become equal. And it may be performed by connecting the adsorption bed in which the second equalization pressure reduction step is completed to an intermediate storage tank that stores the exhaust gas of the first rinse step and the second rinse step, and further reducing the pressure of the adsorption bed in which the second equalization pressure reduction step is completed.

[0021]

[0022]

[0023] Pressure desorption is performed through two different pipes; the initial pressure desorption is carried out through a pipe connected to a compressor that compresses the high-concentration product gas, and after a certain period of time, it can be carried out through a compressor connected to a pipe that performs low-pressure cleaning. During the above pressure desorption, the final pressure reached by the adsorption tower may be below atmospheric pressure to increase the effective adsorption capacity of the adsorbent.

[0024] The above objective is achieved, according to the present invention, by a method for separating a first gas from a mixed gas by adsorbing it using a plurality of adsorption beds equipped with an adsorbent that selectively adsorbs a first gas, comprising: an adsorption step of supplying a mixed gas to the adsorption beds so that the adsorption beds adsorb the first gas and discharge a second gas separated from the first gas; a depressurization step of depressurizing the adsorption beds by discharging the first gas adsorbed on the adsorption beds; a first rinse step of removing gas components other than the first gas by transferring exhaust gas having a higher concentration of the first gas than the mixed gas to the adsorption beds; and a second rinse step of removing gas components other than the first gas by transferring high-purity first gas from a high-pressure product container to the adsorption beds. A second depressurization step in which the adsorption bed, having completed the second rinsing step, is connected to the adsorption bed, having completed the first partial pressurization, after low-pressure cleaning, and the pressure of the adsorption bed, having completed the second rinsing step, is reduced in the same direction as the raw material to partially remove the high-concentration second component present in the outlet portion of the adsorption bed; a depressurization desorption step in which the first gas adsorbed on the adsorption bed, having completed the second depressurization step, is depressurized and desorbed and transferred to the high-pressure product container; a low-pressure cleaning step in which the high-concentration first gas from the intermediate storage tank is transferred to the adsorption bed and low-pressure cleaned; a first partial pressurization step in which the high-concentration first gas from the intermediate storage tank is transferred to the adsorption bed and pressurized; and a second partial pressurization step in which the adsorption bed, having completed the first partial pressurization, is connected to the adsorption bed, having completed the second rinsing step, and the pressure of the adsorption bed, having completed the first partial pressurization, is increased. A pressure equalization step of pressurizing the adsorption bed where the second partial pressurization step is completed by connecting the adsorption bed where the depressurization is being performed with the adsorption bed where the second partial pressurization step is completed;This is achieved by an adsorption separation method comprising: a pressure accumulation step in which the gas from the intermediate storage tank is transferred to the adsorption bed in which the pressure equalization step is completed to pressurize the adsorption bed in which the first pressure equalization step is completed; wherein, in the second rinsing step, a high-purity first gas is introduced into the adsorption bed at a first pressure, and in the depressurization desorption step, the first gas is introduced into the compressor inlet while maintaining the pressure at the time of depressurization and transferred to a high-pressure product container at a pressure higher than the first pressure.

[0025] The first gas may include CO2, and the second gas may include H2.

[0026] According to the present invention, in the second rinsing step, a high-purity first gas is introduced into an adsorption bed at a first pressure, and in the vacuum desorption step, the first gas is compressed to a first pressure by a compressor during the process of being transferred to a high-pressure product container, thereby pressurizing the product gas discharged in the blowdown step to a pressure higher than atmospheric pressure to the pressure at which rinsing is performed, thereby reducing power consumption and reducing power consumption used to create a recirculation stream used for rinsing.

[0027] Figure 1 is a diagram showing a CO2VPSA device located between the SMR+WGS reactor and the H2PSA device.

[0028] FIG. 2 is a schematic diagram showing a VPSA apparatus for performing an adsorption separation method according to an embodiment of the present invention.

[0029] FIG. 3 is a conceptual diagram showing the VPSA process configuration of an adsorption separation method according to an embodiment of the present invention.

[0030] FIG. 4 is a diagram showing each step of the adsorption separation method according to an embodiment of the present invention.

[0031] FIG. 5 is a diagram showing the operation of a valve at each step of an adsorption separation method according to an embodiment of the present invention.

[0032] FIG. 6 is a diagram showing each step of an adsorption separation method according to another embodiment of the present invention.

[0033] FIG. 7 is a diagram showing each step of an adsorption separation method according to another embodiment of the present invention.

[0034] FIG. 8 is a diagram showing each step of an adsorption separation method according to an embodiment of the present invention.

[0035] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, in describing the present invention, descriptions of already known functions or configurations will be omitted in order to clarify the gist of the present invention.

[0036]

[0037] The adsorption separation method (S100) according to an embodiment of the present invention is configured to reduce power consumption by pressurizing the product gas discharged at an atmospheric pressure or higher in the blowdown step to a pressure at which rinsing is performed, and to reduce power consumption used to create the recirculation stream used for rinsing.

[0038] Figure 1 is a diagram showing a CO2VPSA device located between the SMR+WGS reactor and the H2PSA device.

[0039] As shown in Fig. 1, Steam Methane Reforming (SMR) produces a reformed gas containing H2, CO, N2, and CH4 by chemically reacting methane gas contained in natural gas with steam through a catalyst at a certain pressure under the action of a high temperature (700–1,000°C). The reformed gas is introduced into a Water Gas Shift (WGS) reactor, where CO is converted into H2 and CO2.

[0040] H2PSA (Pressure Swing Adsorption) adsorbs N2, CO, CH4, and CO2 and extracts high-purity hydrogen products through pressure increase.

[0041] When a CO2VPSA (Vacuum Pressure Swing Adsorption) device is installed between the SMR+WGS reactor and the H2PSA device, the CO2VPSA device extracts CO2, increasing the H2 partial pressure of the H2PSA feed stream and increasing the H2 recovery rate.

[0042] An adsorption separation method (S100) according to an embodiment of the present invention discloses a method for separating a first gas by adsorbing it from a mixed gas using an adsorption separation system (1). The adsorption separation system (1) according to an embodiment of the present invention may refer to CO2VPSA. The first gas described above may include CO2 gas.

[0043] FIG. 2 is a schematic diagram showing a VPSA apparatus for performing an adsorption separation method (S100) according to an embodiment of the present invention.

[0044] As shown in FIG. 2, the adsorption separation system (1) includes a plurality of adsorption beds (10), a raffinate storage tank (20), a high-pressure product container (30), an intermediate storage tank (40), and a compressor (50).

[0045] A plurality of adsorption beds (10) include a first adsorption bed (V101), a second adsorption bed (V102), a third adsorption bed (V103), a fourth adsorption bed (V104), and a fifth adsorption bed (V105). The first adsorption bed (V101), the second adsorption bed (V102), the third adsorption bed (V103), the fourth adsorption bed (V104), and the fifth adsorption bed (V105) are equipped with an adsorbent that selectively adsorbs a first gas.

[0046] The first adsorption bed (V101), the second adsorption bed (V102), the third adsorption bed (V103), the fourth adsorption bed (V104), and the fifth adsorption bed (V105) can be connected to a supply pipe (sp), a raffinate storage tank (20), a high-pressure product container (30), and an intermediate storage tank (40) by means of a plurality of pipes and a plurality of valves. The supply pipe (sp) transports the mixed gas. A control unit controls the plurality of valves in stages.

[0047] When valve 1a is opened, the mixed gas flows into the first adsorption bed (V101). When valve 2a is opened, the first adsorption bed (V101) and the high-pressure product container (30) are connected by the first discharge pipe (b1). When valve 3a is opened, the first adsorption bed (V101) and the high-pressure product container (30) are connected by the purge pipe (pt). When valve 4a is opened, the first adsorption bed (V101) and the high-pressure product container (30) are connected by the first conduit (t1).

[0048] When valve 5a is opened, the first adsorption bed (V101) and the raffinate storage tank (20) are connected by the second discharge pipe (b2). When valve 6a is opened, the first adsorption bed (V101) and the intermediate storage tank (40) are connected by the second conduit (t2). When valve 7a is opened, the first adsorption bed (V101) and the intermediate storage tank (40) are connected by the fourth conduit (t4). When valve 8a is opened, the first adsorption bed (V101) and the intermediate storage tank (40) are connected by the third conduit (t3).

[0049] When valve 1b is opened, the mixed gas flows into the second adsorption bed (V102). When valve 2b is opened, the second adsorption bed (V102) and the high-pressure product container (30) are connected by the first discharge pipe (b1). When valve 3b is opened, the second adsorption bed (V102) and the high-pressure product container (30) are connected by the purge pipe (pt). When valve 4b is opened, the second adsorption bed (V102) and the high-pressure product container (30) are connected by the first conduit (t1).

[0050] When valve 5b is opened, the second adsorption bed (V102) and the raffinate storage tank (20) are connected by the second discharge pipe (b2). When valve 6b is opened, the second adsorption bed (V102) and the intermediate storage tank (40) are connected by the second conduit (t2). When valve 7b is opened, the second adsorption bed (V102) and the intermediate storage tank (40) are connected by the fourth conduit (t4). When valve 8b is opened, the second adsorption bed (V102) and the intermediate storage tank (40) are connected by the third conduit (t3).

[0051] When valve 1c is opened, the mixed gas flows into the third adsorption bed (V103). When valve 2c is opened, the third adsorption bed (V103) and the high-pressure product container (30) are connected by the first discharge pipe (b1). When valve 3c is opened, the third adsorption bed (V103) and the high-pressure product container (30) are connected by the purge pipe (pt). When valve 4c is opened, the third adsorption bed (V103) and the high-pressure product container (30) are connected by the first conduit (t1).

[0052] When valve 5c is opened, the third adsorption bed (V103) and the raffinate storage tank (20) are connected by the second discharge pipe (b2). When valve 6c is opened, the third adsorption bed (V103) and the intermediate storage tank (40) are connected by the second conduit (t2). When valve 7c is opened, the third adsorption bed (V103) and the intermediate storage tank (40) are connected by the fourth conduit (t4). When valve 8c is opened, the third adsorption bed (V103) and the intermediate storage tank (40) are connected by the third conduit (t3).

[0053] When valve 1d is opened, the mixed gas flows into the fourth adsorption bed (V104). When valve 2d is opened, the fourth adsorption bed (V104) and the high-pressure product container (30) are connected by the first discharge pipe (b1). When valve 3d is opened, the fourth adsorption bed (V104) and the high-pressure product container (30) are connected by the purge pipe (pt). When valve 4d is opened, the fourth adsorption bed (V104) and the high-pressure product container (30) are connected by the first conduit (t1).

[0054] When valve 5d is opened, the fourth adsorption bed (V104) and the raffinate storage tank (20) are connected by the second discharge pipe (b2). When valve 6d is opened, the fourth adsorption bed (V104) and the intermediate storage tank (40) are connected by the second conduit (t2). When valve 7d is opened, the fourth adsorption bed (V104) and the intermediate storage tank (40) are connected by the fourth conduit (t4). When valve 8d is opened, the fourth adsorption bed (V104) and the intermediate storage tank (40) are connected by the third conduit (t3).

[0055] When the 1e valve is opened, the mixed gas flows into the fifth adsorption bed (V105). When the 2e valve is opened, the fifth adsorption bed (V105) and the high-pressure product container (30) are connected by the first discharge pipe (b1). When the 3e valve is opened, the fifth adsorption bed (V105) and the high-pressure product container (30) are connected by the purge pipe (pt). When the 4e valve is opened, the fifth adsorption bed (V105) and the high-pressure product container (30) are connected by the first conduit (t1).

[0056] When the 5e valve is opened, the fifth adsorption bed (V105) and the raffinate storage tank (20) are connected by the second discharge pipe (b2). When the 6e valve is opened, the fifth adsorption bed (V105) and the intermediate storage tank (40) are connected by the second conduit (t2). When the 7e valve is opened, the fifth adsorption bed (V105) and the intermediate storage tank (40) are connected by the fourth conduit (t4). When the 8e valve is opened, the fifth adsorption bed (V105) and the intermediate storage tank (40) are connected by the third conduit (t3).

[0057] FIG. 3 is a conceptual diagram showing the VPSA process configuration of an adsorption separation method (S100) according to an embodiment of the present invention.

[0058] FIG. 4 is a diagram showing each step of the adsorption separation method (S100) according to an embodiment of the present invention.

[0059] As shown in FIG. 4, the first adsorption bed (V101), the second adsorption bed (V102), the third adsorption bed (V103), the fourth adsorption bed (V104), and the fifth adsorption bed (V105) each periodically adsorb and separate the first gas from the mixed gas.

[0060] As illustrated in FIGS. 3 and 4, the adsorption separation method (S100) according to an embodiment of the present invention comprises an adsorption step (a), a depressurization step (b), a first rinse step (c), a second rinse step (d), a depressurization desorption step (e), a purge step (f), a pressurization step (g), a pressure equalization pressurization step (h), and a pressure accumulation step (i). The adsorption separation system (1) according to an embodiment of the present invention can be easily understood through the adsorption separation method (S100).

[0061] The adsorption step (a) is a step in which a mixed gas is supplied to an adsorption bed (10) so that the adsorption bed (10) adsorbs a first gas through an adsorbent, and the second gas separated from the first gas is discharged to a raffinate storage tank (20). The second gas described above may include H2.

[0062] In steps 1, 2, 3, and 4, the first bed continuously performs the adsorption step (a). In steps 1, 2, 3, and 4, the second bed continuously performs the depressurization desorption step (e) (see FIG. 4).

[0063] In Step 1, the control unit opens valves 1a, 2b, 3d, 5a, 8c, and 8e (see FIG. 5).

[0064] In Step 1, the first bed performs the adsorption step (a), the second bed performs the depressurization step (e), the third bed performs the equalization depressurization step (b1), the fourth bed performs the depressurization step (e), and the fifth bed performs the equalization pressurization step (h) (see FIG. 4).

[0065] In Step 2, the control unit opens valves 1a, 2b, 3d, 5a, 6c, and 7e (see FIG. 5).

[0066] In Step 2, the first adsorption bed (V101) performs the adsorption step (a), the second adsorption bed (V102) performs the depressurization step (e), the third adsorption bed (V103) performs the additional depressurization step (b2), the fourth adsorption bed (V104) performs the purging step (f), and the fifth adsorption bed (V105) performs the accumulation step (i) (see FIG. 4).

[0067] In step 3, the control unit opens valves 1a, 2b, 3d, 4c, 5a, 6c, 7e, and 8d (see FIG. 5).

[0068] In Step 3, the first adsorption bed (V101) performs the adsorption step (a), the second adsorption bed (V102) performs the depressurization desorption step (e), the third adsorption bed (V103) performs the first rinse step (c), the fourth adsorption bed (V104) performs the purge step (f), and the fifth adsorption bed (V105) performs the compression step (i) (see FIG. 4).

[0069] In step 4, the control unit opens valves 1a, 2b, 4c, 5a, 6c, 7e, and 8d (see FIG. 5).

[0070] In Step 4, the first adsorption bed (V101) performs the adsorption step (a), the second adsorption bed (V102) performs the depressurization desorption step (e), the third adsorption bed (V103) performs the second rinsing step (d), the fourth adsorption bed (V104) performs the pressurization step (g), and the fifth adsorption bed (V105) performs the accumulation step (i) (see FIG. 4).

[0071] The depressurization step (b) is a step of depressurizing the adsorption bed (10) by discharging the first gas adsorbed on the adsorption bed (10). The depressurization step (b) includes a pressure equalization depressurization step (b1) and an additional depressurization step (b2).

[0072] Based on the first adsorption bed (V101), the equalization pressure reduction step (b1) is a step of transferring the first gas adsorbed on the first adsorption bed (V101) to the fifth adsorption bed (V105) to equalize the pressure of the first adsorption bed (V101). When the first adsorption bed (V101) performs the equalization pressure reduction step (b1), the fifth adsorption bed (V105) performs the equalization pressure increase step (h).

[0073] In step 5, the control unit opens valves 1e, 2c, 3b, 5e, 8a, and 8d (see FIG. 5).

[0074] In Step 5, the first adsorption bed (V101) performs a pressure equalization depressurization step (b1), the second adsorption bed (V102) performs a pressure desorption step (e), the third adsorption bed (V103) performs a pressure desorption step (e), the fourth adsorption bed (V104) performs EQ_PR, and the fifth adsorption bed (V105) performs an adsorption step (a) (see FIG. 4).

[0075] Based on the first adsorption bed (V101), the additional depressurization step (b2) is a step of depressurizing the adsorption bed (10) by transferring the first gas adsorbed on the first adsorption bed (V101) to an intermediate storage tank (40).

[0076] In step 6, the control unit opens valves 1e, 2c, 3b, 5e, 6a, and 7d (see FIG. 5).

[0077] In Step 6, the first adsorption bed (V101) performs an additional depressurization step (b2), the second adsorption bed (V102) performs a purging step (f), the third adsorption bed (V103) performs a depressurization desorption step (e), the fourth adsorption bed (V104) performs a pressure accumulation step (i), and the fifth adsorption bed (V105) performs an adsorption step (a) (see FIG. 4).

[0078] The first rinse step (c) is a step of removing gas components other than the first gas by transferring exhaust gas, in which the concentration of the first gas is higher than that of the mixed gas, to the adsorption bed (10). The gas components discharged in the first rinse step (c) are transferred to an intermediate storage tank (40).

[0079] In step 7, the control unit opens valves 1e, 2c, 3b, 4a, 5e, 6a, 7d, and 8b (see FIG. 5).

[0080] In Step 7, the first adsorption bed (V101) performs the first rinse step (c), the second adsorption bed (V102) performs the purge step (f), the third adsorption bed (V103) performs the depressurization desorption step (e), the fourth adsorption bed (V104) performs the accumulation step (i), and the fifth adsorption bed (V105) performs the adsorption step (a) (see FIG. 4).

[0081] Based on Step 7, when the second adsorption bed (V102) performs the purge step (f), the control unit closes the 1v shut-off valve and the 3v shut-off valve, and opens the 2v shut-off valve. When the 2v shut-off valve is opened, the first conduit (t1) and the purge pipe (pt) are connected by the bypass pipe (bt). Thus, the exhaust gas from the second adsorption bed (V102) is used in the first rinse step (c) of the first adsorption bed (V101).

[0082] The second rinsing step (d) is a step of removing gas components other than the first gas by transferring the high-purity first gas of the high-pressure product container (30) to the adsorption bed (10). The gas components discharged in the second rinsing step (d) are transferred to an intermediate storage tank (40).

[0083] In step 8, the control unit opens valves 1e, 2c, 4a, 5e, 6a, 7d, and 8b (see FIG. 5).

[0084] In Step 8, the first adsorption bed (V101) performs the second rinsing step (d), the second adsorption bed (V102) performs the pressurization step (g), the third adsorption bed (V103) performs the depressurization desorption step (e), the fourth adsorption bed (V104) performs the accumulation step (i), and the fifth adsorption bed (V105) performs the adsorption step (a) (see FIG. 4).

[0085] The depressurization desorption step (e) is a step of depressurizing the first gas adsorbed on the adsorption bed (10) and transferring it to the high-pressure product container (30).

[0086] In the depressurization step (e), the first gas is compressed to a first pressure by a compressor (50) while being transferred to a high-pressure product container (30), and in the second rinse step (d), the high-purity first gas is introduced into the adsorption bed (10) at a first pressure.

[0087] As illustrated in FIG. 1, in order to store CO2 purified to a high purity in a high-pressure product container (30) underground or in liquid form, a step of compressing it to at least 25 bar is required. High-pressure compression is performed using a multi-stage compressor (60) (an 8-stage compressor is used when compressing to 140 bar).

[0088] The adsorption separation method (S100) according to an embodiment of the present invention pressurizes the gas discharged in the depressurization step (e; BD) to a first pressure higher than atmospheric pressure (pressure at which rinsing is performed) through a compressor (50).

[0089] For example, in the adsorption separation method (S100) according to an embodiment of the present invention, the adsorption pressure of the adsorption step (a), the rinsing pressure of the first rinsing step (c) and the second rinsing step (d), and the desorption pressure of the depressurization step (e) may be as shown in [Table 1] below.

[0090] Raw material concentration 1% CO, 4% CH4, 20% CO2, 75% H2 Raw material flow rate 1560 Nm 3 / hr Adsorption pressure 15 barg Desorption pressure -0.4 barg Rinse pressure 2.5 barg

[0091] Therefore, compared to depressurizing to the existing atmospheric pressure and then compressing back to the rinse pressure (the pressure at which the rinse is performed), the power consumption required to pressurize to the rinse pressure can be reduced. Additionally, the power used to create the recirculation flow used for the rinse can also be reduced. In steps 9, 10, 11, 12, and 13, the first bed continuously performs the depressurization desorption step (e) (see FIG. 4). In step 9, the control unit opens valves 1d, 2a, 3c, 5d, 8b, and 8e (see FIG. 5). In Step 9, the first adsorption bed (V101) performs the depressurization step (e), the second adsorption bed (V102) performs EQ_PR, the third adsorption bed (V103) performs the depressurization step (e), the fourth adsorption bed (V104) performs the adsorption step (a), and the fifth adsorption bed (V105) performs the equalization depressurization step (b1) (see FIG. 4).

[0092] In step 10, the control unit opens valves 1d, 2a, 3c, 5d, 6e, and 7b (see FIG. 5).

[0093] In Step 10, the first adsorption bed (V101) performs a depressurization desorption step (e), the second adsorption bed (V102) performs a pressure accumulation step (i), the third adsorption bed (V103) performs a purge step (f), the fourth adsorption bed (V104) performs an adsorption step (a), and the fifth adsorption bed (V105) performs an additional depressurization step (b2) (see FIG. 4).

[0094] In step 11, the control unit opens valves 1d, 2a, 3c, 4e, 5d, 6e, 7b, and 8c (see FIG. 5).

[0095] In Step 11, the first adsorption bed (V101) performs a depressurization desorption step (e), the second adsorption bed (V102) performs a pressure accumulation step (i), the third adsorption bed (V103) performs a purge step (f), the fourth adsorption bed (V104) performs an adsorption step (a), and the fifth adsorption bed (V105) performs a first rinse step (c) (see FIG. 4).

[0096] In step 12, the control unit opens valves 1d, 2a, 4e, 5d, 6e, 7b, and 8c (see FIG. 5).

[0097] In Step 12, the first adsorption bed (V101) performs a depressurization desorption step (e), the second adsorption bed (V102) performs a pressure accumulation step (i), the third adsorption bed (V103) performs a pressure increase step (g), the fourth adsorption bed (V104) performs an adsorption step (a), and the fifth adsorption bed (V105) performs a second rinsing step (d) (see FIG. 4).

[0098] In step 13, the control unit opens valves 1b, 2e, 3a, 5b, 8c, and 8d (see FIG. 5).

[0099] In Step 13, the first adsorption bed (V101) performs the depressurization step (e), the second adsorption bed (V102) performs the adsorption step (a), the third adsorption bed (V103) performs EQ_PR, the fourth adsorption bed (V104) performs the equalization depressurization step (b1), and the fifth adsorption bed (V105) performs the depressurization step (e) (see FIG. 4).

[0100] In steps 9, 10, 11, and 12, the first gas depressurized from the first adsorption bed (V101) is transferred to the high-pressure product container (30) through the first discharge pipe (b1). In step 13, the first gas depressurized from the first adsorption bed (V101) is transferred to the high-pressure product container (30) through the purge pipe (pt).

[0101] The purging step (f) is a step of transferring the high-concentration first gas from the intermediate storage tank (40) to the adsorption bed (10) and performing low-pressure cleaning.

[0102] A significant amount of high-concentration CO2 exists inside the adsorption bed (10) after depressurization desorption is completed. If this is recovered and utilized, the productivity of the process can be increased and the amount of high-purity product recirculated can be reduced.

[0103] When the first adsorption bed (V101) performs the purge step (f), the control unit closes the 1v shut-off valve and the 3v shut-off valve, and opens the 2v shut-off valve. When the 2v shut-off valve is opened, the first conduit (t1) and the purge pipe (pt) are connected by the bypass pipe (bt). Thus, the exhaust gas from the first adsorption bed (V101) is used in the first rinse step (c) of the fourth adsorption bed (V104).

[0104] In step 14, the control unit opens valves 1b, 2e, 3a, 5b, 6d, and 7c (see FIG. 5).

[0105] In Step 14, the first adsorption bed (V101) performs a purging step (f), the second adsorption bed (V102) performs an adsorption step (a), the third adsorption bed (V103) performs a pressure accumulation step (i), the fourth adsorption bed (V104) performs an additional pressure reduction step (b2), and the fifth adsorption bed (V105) performs a pressure reduction desorption step (e) (see FIG. 4).

[0106] In step 15, the control unit opens valves 1b, 2e, 3a, 4d, 5b, 6d, 7c, and 8a (see FIG. 5).

[0107] In Step 15, the first adsorption bed (V101) performs a purging step (f), the second adsorption bed (V102) performs an adsorption step (a), the third adsorption bed (V103) performs a pressure accumulation step (i), the fourth adsorption bed (V104) performs a first rinsing step (c), and the fifth adsorption bed (V105) performs a pressure reduction desorption step (e) (see FIG. 4).

[0108] The pressurization step (g) is a step of transferring the high-concentration first gas from the intermediate storage tank (40) to the adsorption bed (10) and pressurizing it.

[0109] In step 16, the control unit opens valves 1b, 2e, 4d, 5b, 6d, 7c, and 8a (see FIG. 5).

[0110] In Step 16, the first adsorption bed (V101) performs a pressurization step (g), the second adsorption bed (V102) performs an adsorption step (a), the third adsorption bed (V103) performs a pressure accumulation step (i), the fourth adsorption bed (V104) performs a second rinse step (d), and the fifth adsorption bed (V105) performs a pressure reduction desorption step (e) (see FIG. 4).

[0111] The equal pressure pressurization step (h) is a step of equalizing pressure by transferring exhaust gas, in which the concentration of the first gas is higher than that of the mixed gas, to the adsorption bed (10). When the first adsorption bed (V101) performs the equal pressure pressurization step (h), the second adsorption bed (V102) performs the equal pressure reduction step (b1).

[0112] In step 17, the control unit opens valves 1c, 2d, 3e, 5c, 8a, 8b, and 2 (see FIG. 5).

[0113] In Step 17, the first adsorption bed (V101) performs a pressure equalization step (h), the second adsorption bed (V102) performs a pressure equalization step (b1), the third adsorption bed (V103) performs an adsorption step (a), the fourth adsorption bed (V104) performs a pressure reduction step (e), and the fifth adsorption bed (V105) performs a pressure reduction step (e) (see FIG. 4).

[0114] The accumulation step (i) is a step of transferring the high-concentration first gas from the intermediate storage tank (40) to the adsorption bed (10) and pressurizing it. In steps 18, 19, and 20, the first bed continuously performs the accumulation step (i).

[0115] In step 18, the control unit opens valves 1c, 2d, 3e, 5c, 6b, and 7a (see FIG. 5).

[0116] In Step 18, the first adsorption bed (V101) performs the pressure accumulation step (i), the second adsorption bed (V102) performs the additional pressure reduction step (b2), the third adsorption bed (V103) performs the adsorption step (a), the fourth adsorption bed (V104) performs the pressure reduction desorption step (e), and the fifth adsorption bed (V105) performs the purge step (f) (see FIG. 4).

[0117] In step 19, the control unit opens valves 1c, 2d, 3e, 4b, 5c, 6b, 7a, and 8e (see FIG. 5).

[0118] In Step 19, the first adsorption bed (V101) performs the pressure accumulation step (i), the second adsorption bed (V102) performs the first rinse step (c), the third adsorption bed (V103) performs the adsorption step (a), the fourth adsorption bed (V104) performs the pressure reduction desorption step (e), and the fifth adsorption bed (V105) performs the purge step (f) (see FIG. 4).

[0119] In step 20, the control unit opens valves 1c, 2d, 4b, 5c, 6b, 7a, and 8e (see FIG. 5).

[0120] In Step 20, the first adsorption bed (V101) performs the accumulation step (i), the second adsorption bed (V102) performs the second rinsing step (d), the third adsorption bed (V103) performs the adsorption step (a), the fourth adsorption bed (V104) performs the depressurization desorption step (e), and the fifth adsorption bed (V105) performs the pressurization step (g) (see FIG. 4).

[0121] FIG. 6 is a diagram showing each step of an adsorption separation method (S200) according to another embodiment of the present invention.

[0122] A plurality of adsorption beds (10) may further include a sixth adsorption bed (V106). The sixth adsorption bed (V106) may be equipped with an adsorbent that selectively adsorbs the first gas.

[0123] As shown in FIG. 6, the first adsorption bed (V101), the second adsorption bed (V102), the third adsorption bed (V103), the fourth adsorption bed (V104), the fifth adsorption bed (V105), and the sixth adsorption bed (V106) can each periodically adsorb and separate the first gas from the mixed gas.

[0124] FIG. 7 is a diagram illustrating each step of an adsorption separation method (S300) according to another embodiment of the present invention. A plurality of adsorption beds (10) may further include a seventh adsorption bed (V107). The seventh adsorption bed (V107) may be equipped with an adsorbent that selectively adsorbs a first gas.

[0125] As shown in FIG. 7, the first adsorption bed (V101), the second adsorption bed (V102), the third adsorption bed (V103), the fourth adsorption bed (V104), the fifth adsorption bed (V105), the sixth adsorption bed (V106), and the seventh adsorption bed (V107) can each periodically adsorb and separate the first gas from the mixed gas.

[0126] According to the present invention, in the second rinse step (d), a first high-purity gas is introduced into an adsorption bed (10) at a first pressure, and in the process of transferring the first gas to a high-pressure product container (30) in the depressurization desorption step (e), the first gas is compressed to a first pressure by a compressor (50), thereby pressurizing the product gas discharged in the blowdown step to a pressure higher than atmospheric pressure to the pressure at which the rinse is performed, thereby reducing power consumption and reducing power consumption used to create a recirculation stream used for the rinse.

[0127]

[0128] Although specific embodiments of the present invention have been described and illustrated above, it is obvious to those skilled in the art that the present invention is not limited to the described embodiments and can be modified and varied in various ways without departing from the spirit and scope of the invention. Accordingly, such modifications or variations should not be understood individually from the technical spirit or perspective of the present invention, and the modified embodiments should be considered to fall within the scope of the claims of the present invention.

[0129] [Explanation of the symbol]

[0130] S100: Adsorption separation method

[0131] a : Adsorption stage e : Pressure desorption stage

[0132] b : Depressurization stage f : Purge stage

[0133] b1 : Pressure equalization / reduction stage g : Pressurization stage

[0134] b2: Additional depressurization step h: Pressure equalization step

[0135] c : 1st rinse stage i : Accumulation stage

[0136] d : Second rinse step

[0137]

[0138] 1 : Adsorption separation system

[0139] 10: Adsorption bed 20: Raffinate storage tank

[0140] V101 : 1st adsorption bed 30 : High-pressure product container

[0141] V102: 2nd Adsorption Bed 40: Intermediate Storage Tank

[0142] V103 : 3rd adsorption bed 50 : Compressor

[0143] V104: 4th adsorption bed 60: Multistage compressor

[0144] V105 : 5th adsorption bed

Claims

1. A method for separating a first gas from a mixed gas by adsorbing it using a plurality of adsorption beds equipped with an adsorbent that selectively adsorbs the first gas, wherein An adsorption step in which a mixed gas is supplied to the adsorption bed, the adsorption bed adsorbs a first gas, and a second gas separated from the first gas is discharged; A depressurization step of depressurizing the adsorption bed after the adsorption step is completed to discharge a second gas existing in the empty space of the adsorption bed and concentrate a first gas; A first rinse step of removing gas components other than the first gas by transferring exhaust gas having a higher concentration of the first gas than the mixed gas to the adsorption bed after the above depressurization step is completed; A second rinsing step in which the high-purity first gas of a high-pressure product container is transferred to the adsorption bed after the first rinsing step is completed to remove gas components other than the first gas; A depressurization desorption step of depressurizing the first gas adsorbed on the adsorption bed after the second rinsing step is completed and transferring it to the high-pressure product container; A low-pressure cleaning step (purging step) for transferring gas from an intermediate storage tank storing a portion of the gas discharged in the above-mentioned depressurization step to an adsorption bed where the above-mentioned depressurization step is completed, and further desorbing the first gas adsorbed on the adsorption bed where the depressurization step is completed; A first partial pressurization step of transferring and pressurizing a portion of the gas in the intermediate storage tank, which stores the gas discharged in the depressurization step, the first rinse, and the exhaust gas discharged in the second rinse step, to the adsorption bed where the low-pressure cleaning step is completed; A pressure equalization pressurization step in which a portion of the exhaust gas obtained in the pressure reduction step is transferred to the adsorption bed where the first partial pressurization is completed to apply pressure equalization; and It includes a pressure accumulation step of transferring and pressurizing the high-concentration first gas from the intermediate storage tank to the adsorption bed where the above equalization and pressurization is completed, In the second rinse step above, the high-purity first gas is introduced into the adsorption bed at a first pressure, and In the above depressurization step, the first gas is introduced into a compressor while maintaining the pressure during depressurization, compressed above the first pressure, and transferred to a high-pressure product container. Adsorption separation method.

2. In Paragraph 1, The plurality of adsorption beds above includes a first adsorption bed, a second adsorption bed, a third adsorption bed, a fourth adsorption bed, and a fifth adsorption bed, and The first adsorption bed, the second adsorption bed, the third adsorption bed, the fourth adsorption bed, and the fifth adsorption bed each periodically adsorb and separate the first gas from the mixed gas. Adsorption separation method.

3. In Paragraph 1, The above depressurization step is, A pressure equalization and pressure reduction step for reducing pressure by connecting the adsorption bed in which the above adsorption step is completed and the adsorption bed in which the first partial pressurization is completed; and A first parallel pressure reduction step comprising connecting the adsorption bed, upon completion of the first equal pressure reduction step, to an intermediate storage tank to reduce the pressure of the adsorption bed, Adsorption separation method.

4. In Paragraph 1, When the low-pressure washing step is performed in the adsorption bed where the above depressurization desorption step is completed, the exhaust gas of the low-pressure washing step is compressed through a compressor and transferred to the adsorption bed where the above depressurization step is completed and used in the first rinsing step. Adsorption separation method.

5. In Paragraph 1, The gas components discharged from the first rinse step and the second rinse step are transferred to the intermediate storage tank, some of which are introduced into the adsorption bed in the low-pressure washing step and utilized to perform the low-pressure washing step, and some are compressed through a compressor and transferred to the adsorption bed where pressure equalization is completed and utilized for accumulating pressure in the adsorption bed where pressure equalization is completed. Adsorption separation method.

6. In Paragraph 1, A portion of the gas discharged from the first rinse step and the second rinse step is introduced into the adsorption bed in the low-pressure washing step and utilized to perform the low-pressure washing step, a portion is transferred to the adsorption bed and utilized for pressure equalization pressurization, and a portion is also utilized as fuel to supply reaction heat for the methane steam reforming reaction process. Adsorption separation method.

7. In Paragraph 3, The above pressure reduction step comprises a first pressure equalization reduction step for reducing the pressure of the adsorption bed where the adsorption step is completed by connecting the adsorption bed where the adsorption step is completed and the adsorption bed where the second pressure equalization pressurization is completed so that the pressures of the two towers become equal; A cleaning supply step of connecting the adsorption bed, where the first pressure equalization and depressurization is completed, to the adsorption bed, where the depressurization and depressurization is completed, and supplying gas for low-pressure cleaning of the adsorption bed, where the first pressure equalization and depressurization is completed, while depressurizing the adsorption bed, where the first pressure equalization is completed; A second equalization pressure reduction step for reducing the pressure of the adsorption bed where the cleaning supply step is completed by connecting the adsorption bed where the cleaning supply step is completed and the adsorption bed where the first partial pressurization is completed so that the pressures of the two towers become equal; and A first parallel pressure reduction step comprising connecting the adsorption bed, upon which the second equalization pressure reduction step is completed, to an intermediate storage tank storing the exhaust gas of the first rinse step and the second rinse step, and further reducing the pressure of the adsorption bed upon which the second equalization pressure reduction step is completed. Adsorption separation method.

8. In Paragraph 1, Pressure desorption is carried out through two different pipes, the initial pressure desorption is performed through a pipe connected to a compressor that compresses high-concentration product gas, and after a certain period of time, it is performed through a compressor connected to a pipe that performs low-pressure cleaning, Adsorption separation method.

9. A method for separating a first gas from a mixed gas by adsorbing it using a plurality of adsorption beds equipped with an adsorbent that selectively adsorbs the first gas, wherein An adsorption step in which a mixed gas is supplied to the adsorption bed, the adsorption bed adsorbs a first gas, and a second gas separated from the first gas is discharged; A pressure reduction step of reducing the pressure of the adsorption bed by discharging the first gas adsorbed on the adsorption bed; A first rinse step of removing gas components other than the first gas by transferring exhaust gas having a higher concentration of the first gas than the mixed gas to the adsorption bed; A second rinsing step of transferring the high-purity first gas of the high-pressure product container to the adsorption bed to remove gas components other than the first gas; A second depressurization step in which the adsorption bed, having completed the second rinsing step, is connected to the adsorption bed, having completed the first partial pressurization after low-pressure cleaning, and the pressure of the adsorption bed, having completed the second rinsing step, is reduced in the same direction as the raw material, thereby partially removing a high concentration of the second component present in the outlet portion of the adsorption bed from within the adsorption bed; A depressurization step of depressurizing the first gas adsorbed on the adsorption bed after the second depressurization step is completed and transferring it to the high-pressure product container; A low-pressure cleaning step in which a high-concentration first gas from an intermediate storage tank is transferred to the adsorption bed to perform low-pressure cleaning; A first partial pressurization step of transferring and pressurizing the high-concentration first gas from the intermediate storage tank to the adsorption bed; A second partial pressurization step for increasing the pressure of the adsorption bed where the first partial pressurization is completed by connecting the adsorption bed where the second rinsing step is completed; A pressure equalization step of pressurizing the adsorption bed where the second partial pressurization step is completed by connecting the adsorption bed where the depressurization is being performed with the adsorption bed where the second partial pressurization step is completed; and It includes a pressure accumulation step of transferring gas from the intermediate storage tank to the adsorption bed in which the above pressure equalization pressurization step is completed, and pressurizing the adsorption bed in which the first pressure equalization pressurization step is completed. In the second rinse step above, the high-purity first gas is introduced into the adsorption bed at a first pressure, and In the above depressurization desorption step, the first gas is introduced into the compressor inlet while maintaining the pressure during depressurization and is transferred to a high-pressure product container with a pressure higher than the first pressure. Adsorption separation method.

10. In Paragraph 1, The first gas above includes CO2, and The above second gas includes H2, Adsorption separation method.

Images