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The PSA process is briefly described as follows: a. Adsorption process: The shift gas at a pressure of 0.75 Mpa comes in from outside the unit; it first enters the raw gas liquid separation tank to have any entrained liquid droplets removed, and then flows from the bottom of the tower into the adsorption towers that are in the adsorption state within the PSA process (three adsorption towers are in this adsorption state at the same time). Under the sequential adsorption by various adsorbents, components such as H2O and CO2 are adsorbed, while unadsorbed gases such as hydrogen and nitrogen flow out from the top of the tower; after pressure stabilization via a pressure control system, they proceed to the next stage. When the front edge of the mass transfer zone containing the adsorbed impurities (referred to as the adsorption front) reaches the reserved section at the outlet of the bed, the feed gas inlet valve and the product gas outlet valve of that adsorption tower are closed to stop the adsorption process. The adsorption bed begins to enter the regeneration process. b. Pressure equalization and reduction process: This is the process in which, after the adsorption process is completed, the hydrogen and nitrogen gases at higher pressure inside the tower are directed in the direction of adsorption toward other adsorption towers that have already been regenerated and are at lower pressure. This process is not only a means of reducing pressure but also serves to recover the hydrogen and nitrogen present in the dead spaces of the adsorption beds. A total of 6 such pressure equalization and reduction processes are carried out to ensure thorough recovery of the hydrogen and nitrogen gases. c. Reverse desorption process: This is the process in which, after the pressure equalization step is completed, pressure is reduced in the opposite direction to that of adsorption, thereby causing the adsorbed CO2 to be desorbed as a result of reduced pressure. d. Vacuum process: This is the process in which, after the reverse discharge process is completed, hydrogen and nitrogen at higher pressure are used to increase the pressure inside the adsorption tower, in the opposite direction to the adsorption direction. This process corresponds to the pressure equalization and reduction process; it is not only a process of increasing pressure but also one of recovering hydrogen and nitrogen from the dead spaces in the beds of other towers. To ensure an efficient recovery rate of hydrogen and nitrogen, this device includes 6 such pressure equalization and increase processes. f. Product gas pressure increase process: After the pressure equalization and increase process is completed, in order to allow the adsorption tower to switch smoothly to the next adsorption cycle while ensuring that the purity of the product does not fluctuate during this process, it is necessary to use the exhaust gas to gradually and steadily raise the pressure in the adsorption tower to the adsorption pressure, via a pressure increase control valve. This is done to ensure a thorough pressure increase for the product and to minimize any impact on fluctuations in the adsorption pressure. After this process, the adsorption tower completes a full \"adsorption-regeneration\" cycle, preparing itself for the next adsorption cycle. By alternating the above adsorption and regeneration operations among 8 adsorption towers (with 3 adsorption towers always in the adsorption state), continuous separation and purification of gases can be achieved.