Fast cycle pressure swing adsorption method

Abstract

This invention discloses a fast-cycle pressure swing adsorption (PSA) method, comprising: selecting an adsorbent based on the degree of coincidence between the adsorption isotherm and desorption isotherm of the target adsorbate, and the slope k0 of the initial pressure point of the adsorption isotherm. This fast-cycle PSA method, by selecting adsorbents specifically for the target adsorbate, enables fast-cycle PSA cycles, optimizes the PSA process, reduces adsorbent usage, and effectively reduces the footprint and weight of PSA units of the same production scale (equal amounts of feed gas with the same impurity composition and content), thereby lowering PSA operation and production costs. This invention allows for the selection and gradation of adsorbents for various target adsorbates, and has no particular limitations on the candidate adsorbents, making it widely applicable.

Description

Technical Field

[0001] This invention relates to the field of adsorption separation technology, and in particular to a fast-cycle pressure swing adsorption method. Background Technology

[0002] Pressure swing adsorption (PSA) technology can be used for the purification of gases such as hydrogen, helium, and nitrogen, and also for industrial processes such as carbon dioxide capture and the recovery of low-carbon hydrocarbons. Depending on the application, the adsorbent selected for PSA can adsorb impurities that need to be removed or products that need to be produced; the impurities or products adsorbed by the adsorbent are called the adsorbate. Adsorbents, control processes, and equipment are key to the application of PSA technology in production.

[0003] Selecting the appropriate adsorbent based on the type of adsorbate, matching it with the corresponding control process, and further choosing reliable equipment constitutes the general process for achieving an optimized production scheme in pressure swing adsorption (PSA). Generally, PSA achieves continuous production by sequentially switching between at least two towers, each filled with the same type and equal weight of adsorbent. Filling a single adsorption tower with a certain amount of adsorbent can increase product recovery by extending the adsorption cycle; conversely, reducing the amount of adsorbent can shorten the adsorption cycle while maintaining product recovery and reducing the plant's footprint.

[0004] From a sustainable development perspective, while ensuring the overall performance of the pressure swing adsorption (PSA) unit, reducing the amount of adsorbent used, thereby reducing the adsorption tower volume and thus the unit's footprint, is a better option. Therefore, for gas PSA processes using the same raw materials, how to reduce adsorbent usage and optimize the PSA cycle to reduce the unit's footprint and overall weight is a pressing issue that needs to be addressed.

[0005] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] One of the objectives of this invention is to provide a fast-cycle pressure swing adsorption (PSA) method, thereby reducing the amount of adsorbent used, optimizing the PSA cycle, and lowering the operating and production costs of PSA.

[0007] Another objective of this invention is to provide a fast-cycle pressure swing adsorption method that ensures product recovery rate while meeting the productivity requirements of the pressure swing adsorption device.

[0008] To achieve the above objectives, the present invention provides a fast-cycle pressure swing adsorption method, comprising: selecting an adsorbent based on the degree of coincidence between the adsorption isotherm and the desorption isotherm of the target adsorbate and the slope k0 of the initial pressure point of the adsorption isotherm.

[0009] Furthermore, in the above technical solution, the overlap between the adsorption isotherm and desorption isotherm of the selected adsorbent for the target adsorbate satisfies the following condition: at the same pressure, the difference between the adsorption amount of the selected adsorbent for the target adsorbate adsorbent ...

[0010] Furthermore, in the above technical solution, at the same pressure, the adsorption amount of the selected adsorbent adsorption isotherm is less than or equal to the adsorption amount of the desorption isotherm.

[0011] Furthermore, in the above technical solution, the test temperature for the adsorption isotherm and desorption isotherm is 10℃~40℃.

[0012] Furthermore, in the above technical solution, the initial pressure is less than or equal to 10 kPa.

[0013] Furthermore, in the above technical solution, the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is less than or equal to 50.

[0014] Furthermore, in the above technical solution, when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 30 < k0 ≤ 50, the time of each decomposition step in the cycle of pressure swing adsorption is greater than or equal to 24 s; when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 20 < k0 ≤ 30, the time of each decomposition step in the cycle of pressure swing adsorption is greater than or equal to 9 s; when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 10 < k0 ≤ 20, the time of each decomposition step in the cycle of pressure swing adsorption is greater than or equal to 3 s; and when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 1 < k0 ≤ 10, the time of each decomposition step in the cycle of pressure swing adsorption is greater than or equal to 0.05 s.

[0015] Furthermore, in the above technical solution, the process sequence of the pressure swing adsorption cycle includes adsorption, pressure drop equalization, desorption, and pressure rise equalization steps in chronological order.

[0016] Furthermore, in the above technical solution, the process flow adopts an adsorption tower number - number of towers simultaneously in the adsorption state - number of equalization pressure times of 10-3-4, 12-3-6, 4-1-2, 6-1-2, 8-2-3, 8-2-2 or 9-2-3.

[0017] Furthermore, in the above technical solution, when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 20 < k0 ≤ 30, a programmable valve is used to realize the process timing; when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 1 < k0 ≤ 20, an integrated rotary valve is used to realize the process timing.

[0018] Furthermore, in the above technical solution, when there are multiple target adsorbates, adsorbents are selected one by one for each of the multiple target adsorbates, and the selected one or more adsorbents are graded.

[0019] Furthermore, in the above technical solution, the gradation is performed according to the molecular weight of the corresponding target adsorbate from large to small.

[0020] Furthermore, in the above technical solution, the shortest time for each decomposition step in the cycle of pressure swing adsorption is determined by the adsorbent with the largest slope at the initial pressure point of the adsorption isotherm among the adsorbents that form the gradation.

[0021] Furthermore, in the above technical solution, the adsorbent is a microporous molecular sieve, MOFs, carbon molecular sieve, or silica gel.

[0022] Compared with the prior art, the present invention has one or more of the following beneficial effects:

[0023] 1. The fast-cycle pressure swing adsorption method of the present invention can achieve fast-cycle pressure swing adsorption by selecting adsorbents for the target adsorbate, optimize the pressure swing adsorption process, reduce the amount of adsorbent used, effectively reduce the footprint and weight of pressure swing adsorption devices of the same production scale (equal amount of raw gas with the same impurity composition and content), and reduce the operating and production costs of pressure swing adsorption.

[0024] 2. This invention can select adsorbents for various target adsorbates, and there are no particular limitations on the alternative adsorbents, so it has a wide range of applications.

[0025] 3. The fast-cycle pressure swing adsorption method of the present invention can meet the requirements of pressure swing adsorption cycle of various durations by selecting the adsorbent, without the need for additional process steps to compensate for the desorption performance of the adsorbent; it increases the yield of the adsorbent bed and reduces the energy consumption of the regeneration process, such as reducing the amount of purge regeneration gas, reducing the power consumption of vacuuming, or even omitting vacuuming, thereby reducing the overall energy consumption of the process and effectively improving the overall efficiency.

[0026] 4. This invention also provides a gradation method for the adsorbent, offering a simple and easy-to-implement method for the gradation scheme of the adsorbent in fast cycle pressure swing adsorption.

[0027] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, and to make the above and other objects, technical features and advantages of the present invention easier to understand, one or more preferred embodiments are listed below and described in detail with reference to the accompanying drawings. Attached Figure Description

[0028] Figure 1 These are the adsorption isotherms and desorption isotherms of an adsorbent for a certain adsorbate.

[0029] Figure 2 for Figure 1 The slope curves of the adsorption isotherm and the desorption isotherm.

[0030] Figure 3 These are the adsorption isotherms and desorption isotherms of an adsorbent for a certain adsorbate.

[0031] Figure 4 for Figure 3 The slope curves of the adsorption isotherm and the desorption isotherm.

[0032] Figure 5 These are the adsorption and desorption isotherms of another adsorbent for a certain adsorbate.

[0033] Figure 6 for Figure 5 The slope curves of the adsorption isotherm and the desorption isotherm.

[0034] Figure 7 These are the adsorption and desorption isotherms of another adsorbent for a certain adsorbate.

[0035] Figure 8 for Figure 7 The slope curves of the adsorption isotherm and the desorption isotherm.

[0036] Figure 9 This is the adsorption isotherm of an adsorbent for a certain adsorbate and the slope curve of the adsorption isotherm.

[0037] Figure 10 This is the adsorption isotherm of an adsorbent for a certain adsorbate and the slope curve of the adsorption isotherm. Detailed Implementation

[0038] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0039] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0040] In this document, for ease of description, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “up,” etc., are used to describe the relationship of one element or feature to another element or feature in the accompanying drawings. It should be understood that spatial relative terms are intended to encompass different orientations of an object in use or operation, in addition to those depicted in the figures. For example, if an object in the figure is flipped, an element described as “below” or “under” another element or feature would be oriented “above” that element or feature. Thus, the exemplary term “below” can encompass both the downward and upward orientations. An object may also have other orientations (rotated 90 degrees or other orientations), and the spatial relative terms used herein should be interpreted accordingly.

[0041] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.

[0042] According to a specific embodiment of the present invention, the fast-cycle pressure swing adsorption method includes: selecting an adsorbent based on the degree of coincidence between the adsorption isotherm and the desorption isotherm of the adsorbent for the target adsorbate and the slope k0 of the initial pressure point of the adsorption isotherm.

[0043] Furthermore, in one or more exemplary embodiments of the present invention, the test temperature for the adsorption isotherm and desorption isotherm is room temperature, exemplarily 10℃ to 40℃, generally preferably 25℃. The adsorption isotherm refers to the static adsorption isotherm, which has the characteristics of good repeatability, easy acquisition, and applicability to the performance characterization of almost all adsorbents; the desorption isotherm refers to the adsorption amount isotherm obtained by desorbing the adsorbent under the same temperature conditions after completing the static adsorption isotherm test and starting depressurization. The test method for the adsorption isotherm is as follows: pressure is plotted on the x-axis in bar, and adsorption amount is plotted on the y-axis in ml / g; the obtained adsorption isotherm represents the equilibrium adsorption amount of a unit mass of adsorbent under a certain adsorbate pressure.

[0044] Furthermore, in one or more exemplary embodiments of the present invention, the degree of coincidence between the adsorption isotherm and the desorption isotherm refers to the degree of coincidence of the adsorption amounts of the two curves at the same pressure. The degree of coincidence between the adsorption isotherm and the desorption isotherm of the selected adsorbent for the target adsorbate satisfies the following condition: at the same pressure, the difference between the adsorption amounts of the selected adsorbent for the target adsorbate in the adsorption isotherm and the desorption isotherm does not exceed 15% of the adsorption amount in the adsorption isotherm. Furthermore, in one or more exemplary embodiments of the present invention, at the same pressure, the adsorption amount of the selected adsorbent in the adsorption isotherm is less than or equal to the adsorption amount in the desorption isotherm.

[0045] Furthermore, in one or more exemplary embodiments of the present invention, the initial pressure is generally set to be less than or equal to 10 kPa, and this pressure value is the same for different adsorbents.

[0046] Furthermore, in one or more exemplary embodiments of the present invention, if the slope of the initial pressure point of the adsorption isotherm of the adsorbent is greater than 50 for the target adsorbate, it can be determined that the adsorbent is not suitable for continuous production processes of pressure swing adsorption at room temperature. If the slope of the initial pressure point of the adsorption isotherm of the adsorbent is less than or equal to 50 for the target adsorbate, the adsorbent is suitable for pressure swing adsorption processes at room temperature, and the adsorbent can achieve cyclic adsorption and regeneration within a suitable pressure swing adsorption cycle time.

[0047] Furthermore, in one or more exemplary embodiments of the present invention, when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 30 < k0 ≤ 50, the time of each decomposition step in the cycle of pressure swing adsorption is greater than or equal to 24 s; when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 20 < k0 ≤ 30, the time of each decomposition step in the cycle of pressure swing adsorption is greater than or equal to 9 s; when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 10 < k0 ≤ 20, the time of each decomposition step in the cycle of pressure swing adsorption is greater than or equal to 3 s; and when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 1 < k0 ≤ 10, the time of each decomposition step in the cycle of pressure swing adsorption is greater than or equal to 0.05 s.

[0048] Furthermore, in one or more exemplary embodiments of the present invention, the process sequence of the pressure swing adsorption cycle includes adsorption, pressure drop equalization, desorption, and pressure rise equalization steps in chronological order.

[0049] Furthermore, in one or more exemplary embodiments of the present invention, a process flow is adopted in which the number of adsorption towers - the number of towers simultaneously in the adsorption state - the number of equalization pressures is 10-3-4, 12-3-6, 4-1-2, 6-1-2, 8-2-3, 8-2-2 or 9-2-3.

[0050] Furthermore, in one or more exemplary embodiments of the present invention, when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 20 < k0 ≤ 30, a programmable valve is used to implement the process timing; when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 1 < k0 ≤ 20, an integrated rotary valve is used to implement the process timing.

[0051] Furthermore, in one or more exemplary embodiments of the present invention, the adsorbent is a microporous molecular sieve, MOFs, carbon molecular sieve, or silica gel. Exemplarily, for molded adsorbents, the particle size ranges from 0.4 mm to 2.5 mm, and the molded adsorbent can be in the form of spheres, strips, columns, or core-shell structures. For structured adsorbents, the thickness of the adsorbent coating is between 50 μm and 400 μm. Structured adsorbents generally refer to adsorbent powder coated on a porous carrier, which can be a sintered metal porous material, alumina sintered porous material, or plexiglass fiber porous material, etc.

[0052] Furthermore, in one or more exemplary embodiments of the present invention, when there are multiple target adsorbates, for example, when the feed gas contains multiple components, adsorbents are selected one by one for each target adsorbate, and the selected one or more adsorbents are graded. Further, in one or more exemplary embodiments of the present invention, the graded adsorbents are adsorbed sequentially according to the molecular weight of the corresponding target adsorbates from largest to smallest. The same adsorbent generally adsorbs larger molecular weight adsorbates more readily; however, large molecular weight impurities are not easily desorbed. Therefore, arranging the graded adsorbents to adsorb adsorbates sequentially according to molecular weight is beneficial for adsorbent desorption. Further, in one or more exemplary embodiments of the present invention, the shortest time for each decomposition step in the pressure swing adsorption cycle is determined by the adsorbent with the largest slope of the initial pressure point of the adsorption isotherm among the adsorbents forming the grade. The relationship between the shortest time for each decomposition step in the pressure swing adsorption cycle and the slope of the initial pressure point of the adsorption isotherm for each adsorbent is as described in the above technical solutions and will not be repeated here.

[0053] According to a specific embodiment of the fast-cycle pressure swing adsorption method of the present invention, the static adsorption isotherm and desorption isotherm of the adsorbent are first measured. Then, the derivative (tangent slope) of the fitted curves of the adsorption and desorption isotherms is calculated to obtain the tangent slope at each point and thus obtain the isotherm slope curve. Combined with... Figures 1-10 The adsorption and desorption isotherms and their corresponding slope curves for the adsorbent are shown below. The selection of the adsorbent for a given gas source is as follows:

[0054] When the adsorption isotherm and desorption isotherm of the adsorbent for a certain adsorbate, and the corresponding slope curve are measured, as shown in the figure... Figure 1 and Figure 2 As shown, this adsorbent is suitable for fast-cycle pressure swing adsorption, and the time for each decomposition step in the cycle should be greater than or equal to 0.05 s.

[0055] When the adsorption isotherm and desorption isotherm of the adsorbent for a certain adsorbate, and the corresponding slope curve are measured, as shown in the figure... Figure 3 and Figure 4As shown, this adsorbent is suitable for fast cycle pressure swing adsorption where the time for each decomposition step in the cycle is greater than or equal to 3 seconds.

[0056] When the adsorption isotherm and desorption isotherm of the adsorbent for a certain adsorbate, and the corresponding slope curve are measured, as shown in the figure... Figure 5 and Figure 6 As shown, this adsorbent is suitable for fast cycle pressure swing adsorption where the time for each decomposition step in the cycle is greater than or equal to 9 s.

[0057] When the adsorption isotherm and desorption isotherm of the adsorbent for a certain adsorbate, and the corresponding slope curve are measured, as shown in the figure... Figure 7 and Figure 8 As shown, this adsorbent is suitable for fast cycle pressure swing adsorption where the time for each decomposition step in the cycle is greater than or equal to 24 s.

[0058] When the gas source contains multiple components that require adsorbate, the adsorbents can be selected and graded according to the above method. The applicable cycle of the composite bed with multiple adsorbent grades is determined by the adsorbent that requires the longest time for the decomposition step.

[0059] When the adsorption isotherm curve of the adsorbent for a certain adsorbate and the slope of the tangent line of the adsorption isotherm are measured, as shown in the figure... Figure 9 or Figure 10 As shown, since the adsorbent cannot desorb at the measured temperature, a desorption isotherm at the same temperature cannot be obtained; at the same time, the slope of the initial pressure point of the adsorption isotherm of the adsorbent is greater than 50, so the adsorbent cannot be used to realize the room temperature pressure swing adsorption process.

[0060] Taking a typical 8-2-2 process (i.e., eight adsorption towers, two of which are simultaneously in adsorption steps, with each cycle involving two pressure drop and pressure rise cycles) as an example, the pressure swing adsorption cycle is the time from the start of one adsorption step to the completion of the final charging and preparation for the next adsorption step. The time of each pressure swing adsorption cycle is the sum of the times of all decomposition steps. Referring to Table 1, if the time of each decomposition step is 30s, then the entire pressure swing adsorption cycle is 480s (8min). In Table 1, "adsorption" represents the adsorption step; "charging" represents the final charging step; "drop 1 / rise 1" represents the first pressure drop / rise step; "drop 2 / rise 2" represents the second pressure drop / rise step; "forward" represents the forward discharge step; "reverse" represents the reverse discharge step; and "purge" represents the purging step using forward discharge gas.

[0061] Table 1. Decomposition steps of a typical 8-2-2 process

[0062]

[0063] The fast cycle pressure swing adsorption method of the present invention will be described in more detail below by way of specific embodiments. It should be understood that the embodiments are merely exemplary and the present invention is not limited thereto.

[0064] Example 1

[0065] In this embodiment, the composition (volume fraction) of the feed gas is 1% nitrogen, 8% methane, and 91% hydrogen, with a pressure of 2 MPa, a temperature of 20°C, and a flow rate of 1000 Nm³. 3 / h. The goal is to purify and produce hydrogen product (hydrogen purity: 99.999%) from this feed gas using pressure swing adsorption (PSA) technology.

[0066] In this embodiment, the purification process is determined to be a typical 10-3-4 process, i.e., 10 adsorption towers, 3 towers adsorbing simultaneously, 4 pressure equalization processes, with the yield remaining constant at 85%. The material balance is shown in Table 2. According to the fast-cycle pressure swing adsorption method of the present invention, the adsorption isotherms and desorption isotherms of the adsorbent for two adsorbates (nitrogen and methane), and their corresponding slope curves, were measured. The three adsorbents shown in Table 3 can achieve a room-temperature fast-cycle pressure swing adsorption process.

[0067] Table 2 Material Balance

[0068]

[0069] Table 3. Determination results of three adsorbents

[0070] Types of adsorbents slope at the initial point of nitrogen 0.1MPa nitrogen adsorption capacity slope at the initial point of methane 0.1 MPa methane adsorption capacity Molecular sieve 1 9 9ml / g 16 13ml / g Molecular sieve 2 18 13ml / g 38 20ml / g Activated carbon 1 7 7ml / g 29 20ml / g

[0071] Based on the above adsorbent measurement results, hydrogen can be produced by purifying the above-mentioned raw gas using a single adsorbent, or hydrogen purification can be achieved using an adsorbent gradation method. The relationship between adsorption period and adsorption tower volume for different adsorbents is shown in Table 4.

[0072] Table 4 Applicable adsorption cycles and adsorption tower volumes for different adsorbent loading schemes

[0073] Serial Number Adsorbent filling scheme Optimal adsorption cycle / min <![CDATA[Adsorption tower volume / Nm 3 > 1 Molecular sieve 1 2 0.16 2 Molecular sieve 2 8 0.30 3 Molecular sieve 1 + activated carbon 1 3 0.14 4 Molecular sieve 2 + activated carbon 1 3 0.12

[0074] In adsorbent filling scheme 1, only molecular sieve 1 is used. This adsorbent can adapt to a faster adsorption cycle and has the shortest adsorption cycle. However, the adsorbent has a low adsorption capacity for nitrogen and methane, especially for methane. Therefore, a larger amount of adsorbent needs to be filled.

[0075] In adsorbent loading scheme 2, only molecular sieve 2 is used. Molecular sieve 2 has a high adsorption capacity for both adsorbates, but the initial slope of the methane adsorption isotherm is high, making it difficult to desorb. Therefore, the adsorption cycle is long. Long-cycle adsorption in a single tower requires a larger amount of adsorbent, so this loading scheme requires the largest adsorption tower volume.

[0076] Adsorbent loading scheme 3 uses a graded bed composed of molecular sieve 1 and activated carbon 1. Since the molecular weight of methane is greater than that of nitrogen, the graded loading of the adsorbent ensures that the feed gas first adsorbs methane via activated carbon 1, and then adsorbs nitrogen via molecular sieve 1. The adsorption period is determined by the adsorbent with the largest initial slope of the adsorption isotherm, and the preferred adsorption period is 3 minutes.

[0077] Adsorbent loading scheme 4 uses a graded bed composed of molecular sieve 2 and activated carbon 1. Since the molecular weight of methane is greater than that of nitrogen, the adsorbent is graded to ensure that the feed gas first adsorbs methane through activated carbon 1, and then adsorbs nitrogen through molecular sieve 2. Although the adsorption period is determined by the adsorbent with the largest initial slope of the adsorption isotherm, the activated carbon bed ensures complete methane adsorption without introducing it into the molecular sieve bed, thus maximizing the effectiveness of both adsorbents. The optimal adsorption period is 3 minutes. This graded scheme balances the adsorption period and the adsorbent's adsorption capacity for the adsorbate, leveraging the characteristics of each adsorbent for different adsorbates. It achieves optimal graded processing and operating cycle while minimizing the adsorption tower volume.

[0078] The foregoing description of specific exemplary embodiments of the present invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. Any simple modifications, equivalent changes, and alterations made to the foregoing exemplary embodiments should fall within the scope of protection of the present invention.

Claims

1. A fast cycle pressure swing adsorption process characterized by, The method comprises the following steps: selecting an adsorbent according to the coincidence degree of the adsorption isotherm and the desorption isotherm of the target adsorbate on the adsorbent, and the slope k0 of the initial pressure point of the adsorption isotherm; the coincidence degree of the adsorption isotherm and the desorption isotherm of the target adsorbate on the selected adsorbent satisfies: at the same pressure, the adsorption amount of the adsorption isotherm is less than or equal to the adsorption amount of the desorption isotherm; the test temperature of the adsorption isotherm and the desorption isotherm is 10-40℃; and the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is less than or equal to 50; when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 30 when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 20 when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 10 and when the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 1 2. The fast cycle pressure swing adsorption process of claim 1, wherein, The coincidence degree of the adsorption isotherm and the desorption isotherm of the target adsorbate on the selected adsorbent satisfies: at the same pressure, the difference between the adsorption amounts of the adsorption isotherm and the desorption isotherm of the target adsorbate on the selected adsorbent is not more than 15% of the adsorption amount of the adsorption isotherm.

3. The fast cycle pressure swing adsorption process of claim 2, wherein, The initial pressure is less than or equal to 10 KPa.

4. The rapid cycle pressure swing adsorption process of claim 1 wherein, The process timing of the cycle of the pressure swing adsorption comprises, in chronological order, the steps of adsorption, pressure equalization decrease, desorption and pressure equalization increase.

5. The rapid cycle pressure swing adsorption process of claim 1 wherein, The process flow is 10-3-4, 12-3-6, 4-1-2, 6-1-2, 8-2-3, 8-2-2 or 9-2-3 in terms of the number of adsorption towers, the number of towers simultaneously in the adsorption state and the number of pressure equalization times.

6. The rapid cycle pressure swing adsorption process of claim 1 wherein, When the slope of the initial pressure point of the adsorption isotherm of the selected adsorbent is 20 7. The fast cycle pressure swing adsorption process of claim 1 wherein, When the target adsorbate is multiple, one adsorbent is selected for each target adsorbate, and one or more selected adsorbents are formed into a gradation.

8. The fast cycle pressure swing adsorption method of claim 7, wherein, The gradation is sequentially adsorbed from large to small according to the molecular weight of the corresponding target adsorbate.

9. The rapid cycle pressure swing adsorption method of claim 7, wherein, The shortest time of each decomposition step sequence in the cycle of the pressure swing adsorption is determined by the adsorbent with the largest slope of the initial pressure point of the adsorption isotherm among the adsorbents forming the gradation.

10. The rapid cycle pressure swing adsorption process of claim 1 wherein, The adsorbent is a microporous molecular sieve, MOFs, carbon molecular sieve or silica gel.

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