KR-20260063205-A - ADSORPTION PROCESS

KR20260063205AKR 20260063205 AKR20260063205 AKR 20260063205AKR-20260063205-A

Abstract

An adsorption separation method is disclosed. The adsorption separation method of the present invention is 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, and is characterized by comprising an adsorption step, a depressurization step, a first rinse step, a second rinse step, a depressurization desorption step, a purge step, a pressurization step, a pressure equalization pressurization step, and a pressure accumulation step. According to the present invention, in the second rinse 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 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 at an atmospheric pressure or higher in the blowdown step to a pressure at which rinsing is performed, thereby reducing power consumption and reducing power consumption used to create a recirculation stream used for rinsing.

Inventors

박종호
윤형진
박종기
범희태
한상섭
추고연

Assignees

한국에너지기술연구원

Dates

Publication Date: 20260507
Application Date: 20241030

Claims (10)

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

Description

Adsorption Separation Method {ADSORPTION PROCESS} 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. 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 introduced into a Water Gas Shift (WGS) reactor, where CO is converted into H₂ and CO₂ . Pressure Swing Adsorption (PSA) adsorbs N₂ , CO, CH₄ , and CO₂ and extracts high-purity hydrogen products through pressure increase. When a CO2 VPSA (Vacuum Pressure Swing Adsorption) device is installed between the SMR+WGS reactor and the H2 PSA device, the CO2 VPSA device extracts CO2 , increasing the H2 partial pressure of the H2 PSA feed stream and increasing the H2 recovery rate. In this regard, U.S. Register No. 8709136 (hereinafter referred to as the 'prior art') discloses an adsorption process. The adsorption process of the prior art is a process for separating a first gas ( CO₂ ) from a feed gas mixture containing the first gas and a second gas ( H₂ ), and uses five or more adsorption beds containing a selective adsorbent for the first gas. 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. The adsorption process of the prior art initiates a process of producing high-purity CO2 by reducing the pressure to a vacuum in the blowdown step and storing the CO2 product in a CO2 product tank. At this time, since the component to be separated is a strongly adsorbed component, a rinse step must be performed to recirculate the heavy component obtained as a product in order to purify the component. Figure 1 is a diagram showing a CO2 VPSA unit located between an SMR+WGS reactor and an H2 PSA unit. FIG. 2 is a schematic diagram showing a VPSA apparatus for performing an adsorption separation method according to an embodiment of the present invention. FIG. 3 is a conceptual diagram showing the VPSA process configuration of an adsorption separation method according to an embodiment of the present invention. FIG. 4 is a diagram showing each step of the adsorption separation method according to an embodiment of the present invention. 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. FIG. 6 is a diagram showing each step of an adsorption separation method according to another embodiment of the present invention. FIG. 7 is a diagram showing each step of an adsorption separation method according to another embodiment of the present invention. FIG. 8 is a diagram showing each step of an adsorption separation method according to an embodiment of the present invention. 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. 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. Figure 1 is a diagram showing a CO2 VPSA unit located between an SMR+WGS reactor and an H2 PSA unit. 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 . H₂ PSA (Pressure Swing Adsorption) adsorbs N₂ , CO, CH₄ , and CO₂ and extracts high-purity hydrogen products through pressure increase. When a CO2 VPSA (Vacuum Pressure Swing Adsorption) device is installed between the SMR+WGS reactor and the H2 PSA device, the CO2 VPSA device extracts CO2 , increasing the H2 partial pressure of the H2 PSA feed stream and increasing the H2 recovery rate. 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 pres