Method for separating alkyne olefin with same carbon number

Abstract

The invention discloses a method for separating alkyne olefins with the same carbon number, which comprises the following steps: a mixed fluid containing the alkyne olefins with the same carbon number is contacted with crystalline porous organic salt with charge separation confinement channels, the crystalline porous organic salt selectively adsorbs alkyne in the mixed fluid, and the alkyne olefins with the same carbon number are separated; the molecular formula of the crystalline porous organic salt is (C25H16S4O12) (C6H16N2) 2, and the crystalline porous organic salt has a three-dimensional structure which is formed by connecting 4, 4 ', 4', 4 '-methane tetra-tetrabenzene sulfonate (C25H16S4O12) 4-and trans-1, 4-cyclohexanediamine cations (C6H16N2) 22 + through intermolecular ionic bonds. According to the method, the alkyne-olefin mixture with the same carbon number can be efficiently separated, the crystalline porous organic salt adsorbent is easy to regenerate, the hydrothermal stability is good, and self-repairing can be achieved under the mild condition.

Description

Technical Field

[0001] The invention relates to the technical field of chemical separation, and in particular to a method for separating alkynes and alkenes with the same carbon number. Background Art

[0002] Ethylene (C2H4) and propylene (C3H6) are the most important basic raw materials in the chemical industry. They are the raw materials for the production of three major synthetic materials - plastics, synthetic fibers and synthetic rubber. They are also the raw materials for the production of major petrochemical products such as propylene oxide and acrylonitrile. According to statistics, the global annual total output of the two has exceeded 300 million tons. At present, the production process of ethylene and propylene mainly relies on the cracking of naphtha. However, in the production process, alkynes with the same carbon number cannot be avoided as impurities. However, the presence of trace alkyne impurities will cause the catalyst required in the olefin polymerization process to poison, affecting the quality of the polymerized olefins. Therefore, in order to obtain olefins of polymerization grade purity, the trace alkynes present in them must be removed. The current methods used for the removal of trace alkynes mainly include selective hydrogenation catalyzed by precious metals or solvent absorption. These methods will have problems such as high cost and environmental pollution. Therefore, it is urgent to develop a new separation technology to achieve the efficient separation of alkynes with the same carbon number.

[0003] Physical adsorption is a relatively energy-saving and efficient separation technology. However, due to the similar physicochemical properties of alkynes and alkenes with the same carbon number, their separation is extremely challenging. Recently, organic framework materials connected by non-covalent bonds, such as hydrogen-bonded organic framework materials (HOFs) and supramolecular organic framework materials (SOFs), have the same advantages as metal-organic framework materials (MOFs), such as large specific surface area, finely adjustable pore size and pore environment, and have potential application prospects in the field of gas adsorption. In addition, compared with MOFs, they also have unique self-healing properties due to weak non-covalent and non-coordinated connecting bonds. This feature can save more costs, thus giving them higher practical application value. However, due to the weak polarity of the pores constructed by pure organic molecules and the lack of effective functional sites that can recognize polar alkyne molecules, there is very little research on the separation of alkynes and alkenes with the same carbon number using non-covalently linked organic framework materials, and the separation effect of existing materials is poor. When they separate alkynes and alkenes with the same carbon number at a molar ratio of 1 / 99, their selectivity is less than 10. Therefore, there is an urgent need to explore new non-covalently linked organic framework materials to achieve efficient separation of alkynes and alkenes with the same carbon number.

[0004] The patent specification with publication number CN117487176A discloses a crystalline porous organic salt and its preparation method and application. The preparation method comprises the following steps: 1) dissolving 1,3,6,8-pyrenetetrasulfonic acid tetrasodium salt in an acetonitrile aqueous solution to obtain solution A; 2) dissolving 1,3,6,8-tetra-(p-aminophenyl)-pyrene in a hydrochloric acid aqueous solution, adding an acetonitrile aqueous solution to obtain solution B; 3) mixing solution A and solution B, standing at room temperature, generating yellow-green crystals, filtering, and obtaining a crystalline porous organic salt CPOS-8. At 298K and 1 bar, this CPOS-8 was subjected to a penetration experiment of a mixed gas of C2H2 / C2H4 / He with a volume ratio of 1:1:8 and a total flow rate of 2.5mL / min, showing a separation time of 8.9min. Although CPOS-8 can separate acetylene and ethylene to a certain extent, the separation effect is still not excellent. Summary of the invention

[0005] In view of the above technical problems and the deficiencies in the art, the present invention provides a method for separating acetylenes with the same carbon number, which has excellent separation effects on acetylenes with the same carbon number such as C2 and C3.

[0006] A method for separating alkynes with the same carbon number comprises: contacting a mixed fluid containing alkynes with the same carbon number with a crystalline porous organic salt having charge separation confined pores, wherein the crystalline porous organic salt selectively adsorbs alkynes in the mixed fluid to achieve separation of alkynes with the same carbon number;

[0007] The molecular formula of the crystalline porous organic salt is (C 25 H 16 S4O 12 )(C6H 16 N2)2, having 4,4',4",4"-methanetetrayltetrabenzenesulfonate (C 25 H 16 S4O 12 ) 4- With trans-1,4-cyclohexanediamine cation (C6H 16 N2)2 2+ The three-dimensional structure is formed by intermolecular ionic bonds, wherein a single 4,4',4",4"-methanetetrayltetrabenzenesulfonate is connected to four adjacent trans-1,4-cyclohexanediamine cations via 12 NH·…·OS ionic bonds.

[0008] The alkyne and olefin with the same carbon number can be acetylene and ethylene, or propyne and propylene.

[0009] The crystalline porous organic salt has ultra-microporous periodic one-dimensional pores, and the pore size is

[0011] In the mixed fluid, based on the total molar amount of alkynes and olefins as 100%, the molar content of alkynes may be between 1% and 70%, and further between 1% and 10%.

[0012] The contacting mode of the mixed fluid and the crystalline porous organic salt may be any one or more combinations of fixed bed adsorption, fluidized bed adsorption and moving bed adsorption.

[0013] In some embodiments, the contact method between the mixed fluid and the crystalline porous organic salt is fixed bed adsorption, including: under set adsorption temperature and pressure, the mixed fluid enters a fixed bed adsorption column filled with the crystalline porous organic salt at a set flow rate, the olefin component preferentially penetrates the bed layer, and a high-purity olefin component is directly obtained from the outlet of the adsorption column.

[0014] The crystalline porous organic salt of the present invention can achieve a high adsorption capacity for the alkyne component in the mixed system of alkynes and alkenes with the same carbon number within a certain temperature range. The adsorption temperature can be 0-40° C. and the adsorption pressure can be 0.5-10 atm.

[0015] The method for separating alkynes with the same carbon number may further include: after separation of alkynes with the same carbon number, desorbing alkynes at a temperature of 60 to 120° C. and a pressure of 0 to 1 atm to regenerate the crystalline porous organic salt. In the present invention, there is a physical force between the crystalline porous organic salt and the adsorbate such as alkynes, and desorption and regeneration are easy and the conditions are mild.

[0016] As a general inventive concept, the present invention also provides an application of a crystalline porous organic salt having charge separation confined pores in the separation of alkynes and alkenes with the same carbon number, wherein the crystalline porous organic salt selectively adsorbs alkynes in a mixed fluid containing alkynes and alkenes with the same carbon number after contacting the mixed fluid, thereby achieving the separation of alkynes and alkenes with the same carbon number;

[0017] The molecular formula of the crystalline porous organic salt is (C 25 H 16 S4O 12 )(C6H 16 N2)2, having 4,4',4",4"-methanetetrayltetrabenzenesulfonate (C 25 H 16 S4O 12 ) 4- With trans-1,4-cyclohexanediamine cation (C6H 16 N2)2 2+ The three-dimensional structure is formed by intermolecular ionic bonds, wherein a single 4,4',4",4"-methanetetrayltetrabenzenesulfonate is connected to four adjacent trans-1,4-cyclohexanediamine cations via 12 NH·…·OS ionic bonds.

[0018] The specific technical solutions, selection and optimization of technical means in the above application can refer to the above method for separating alkynes with the same carbon number.

[0019] The alkyne and olefin with the same carbon number can be acetylene and ethylene, or propyne and propylene.

[0020] The crystalline porous organic salt has ultra-microporous periodic one-dimensional pores, and the pore size is

[0022] In the mixed fluid, based on the total molar amount of alkynes and olefins as 100%, the molar content of alkynes may be between 1% and 70%, and further between 1% and 10%.

[0023] The contacting mode of the mixed fluid and the crystalline porous organic salt may be any one or more combinations of fixed bed adsorption, fluidized bed adsorption and moving bed adsorption.

[0024] The crystalline porous organic salt of the present invention can achieve a high adsorption capacity for the alkyne component in the mixed system of alkynes and alkenes with the same carbon number within a certain temperature range. The adsorption temperature can be 0-40° C. and the adsorption pressure can be 0.5-10 atm.

[0025] The crystalline organic salt of the present invention has good hydrothermal stability and can perform self-repair under mild conditions to achieve self-repair of collapsed structures.

[0026] The crystalline organic salt of the present invention has separation selectivities of 25.1 and 43.9 respectively for acetylene / ethylene and propyne / propylene mixed gases with a molar ratio of 1:99 at 298K and 100kPa.

[0027] The crystalline porous organic salt with charge separation confined channels described in the present invention can be synthesized by at least one of the well-known coprecipitation method, interface diffusion method, solvent thermal method, etc.

[0028] The removal of alkynes with the same carbon number is extremely challenging because of their similar physicochemical properties and the presence of alkyne impurities with the same carbon number in alkenes as trace components. However, alkyne molecules are more polar than olefin molecules, and the acidity of H atoms is also stronger. Therefore, the separation of acetylene / ethylene and propyne / propylene with the same carbon number in alkynes can be achieved by introducing charged polar sites into non-covalently linked organic framework materials and precisely controlling the pore size to specifically identify acetylene or propyne.

[0029] The crystalline porous organic salt with charge separation confined pores involved in the present invention has a large number of regularly arranged negatively charged -SO3 - Anions and positively charged -NH3 +Cations, which form a special electrostatic environment in the confined space of the crystalline porous organic salt of the specific structure of the present invention, can selectively identify and adsorb acetylene or propyne molecules from the mixed gas containing acetylene / ethylene or propyne / propylene, thereby achieving efficient separation of acetylenes and alkenes with the same carbon number.

[0030] The inventors have found that the crystalline porous organic salt (which can be recorded as CPOS-1) of the above-mentioned specific structure of the present invention has good hydrothermal stability and can adapt to harsh application environments in industry; it can selectively identify and adsorb acetylene or propyne gas from a mixed gas containing acetylene / ethylene or propyne / propylene, and efficiently separate a mixed gas of acetylene and olefins with the same carbon number. The anions and cations in the crystalline porous organic salt of the present invention can form a regular arrangement structure on the surface of the pores, so that a special electrostatic environment is formed in the confined space of the pores of the specific structure of the material of the present invention. On the one hand, the introduction of anions and cations in the specific structure of the material of the present invention can enhance the selective recognition of alkynes in the mixed system of alkynes and olefins with the same carbon number. On the other hand, the material also has a finely controlled pore size, which can strengthen the confinement effect, thereby enhancing the effect with alkyne molecules in the mixed gas of alkynes and olefins with the same carbon number, thereby improving the selectivity of the separation of alkynes and olefins with the same carbon number. The above two characteristics are indispensable, and only when the two exist at the same time can the purpose of effectively separating alkynes and olefins with the same carbon number required by the present invention be achieved.

[0031] The crystalline porous organic salt CPOS-1 with charge separation confined pores of the present invention can be used directly as an adsorbent alone, or it can be compounded with other materials to form adsorbent materials of different shapes and sizes to meet the requirements of different industrial reaction devices for adsorbent filler particle specifications.

[0032] The invention can efficiently adsorb acetylene or propyne gas from the mixed gas of acetylene and olefin with the same carbon number to purify ethylene or propylene. The crystalline porous organic salt adsorbent is easy to regenerate and has good hydrothermal stability.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. On the one hand, the surface of the crystalline porous organic salt CPOS-1 of the present invention has a large number of regularly arranged -SO3 - Anion and -NH3 + Cationic functional groups, these ions form a special electrostatic environment in the spatially confined pores of the specific structure of the crystalline porous organic salt of the present invention, and highly selectively capture alkynes from the mixed gas of alkynes and alkenes with the same carbon number. On the other hand, the material also has a finely controlled pore size, which can strengthen the confinement effect, thereby enhancing the adsorption of alkyne molecules in the mixed gas of alkynes and alkenes with the same carbon number, thereby improving the selectivity of the separation of alkynes and alkenes with the same carbon number. The combination of these two aspects can achieve the technical effect of the present invention of efficiently separating alkynes and alkenes with the same carbon number.

[0035] 2. The crystalline porous organic salt CPOS-1 with charge separation confined channels is easy to desorb and regenerate, which has great advantages over traditional chemical absorbents. It can reduce the energy consumption of material regeneration. At the same time, the material can be regenerated and reused.

[0036] 3. The crystalline porous organic salt CPOS-1 with charge separation confined channels has excellent hydrothermal stability, as well as excellent cyclic stability and unique self-healing properties. These properties show the potential application value of crystalline porous organic salts with charge separation confined channels in industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The powder X-ray diffraction (PXRD) pattern of the crystalline porous organic salt prepared in Example 2 for stability investigation;

[0038] Figure 2 is a single component adsorption isotherm diagram of acetylene and ethylene of the crystalline porous organic salt in Example 5 at 278K, 298K, 308K, 0-100kPa;

[0039] Figure 3 The single component adsorption isotherms of propyne and propylene of the crystalline porous organic salt in Example 5 at 278K, 298K, 308K, and 0-100kPa;

[0040] Figure 4 The IAST separation selectivity diagram of the crystalline porous organic salt in Example 6 for a 1 / 99 molar ratio acetylene / ethylene or propyne / propylene mixed gas under the conditions of 298K and 0-100kPa;

[0041] Figure 5 This is a penetration curve of the C2H2 / C2H4 (v:v=1:99) mixed gas on the crystalline porous organic salt in Example 7, and the mixed gas flow rate is 2 mL / min;

[0042] Figure 6 This is a penetration curve of the C3H4 / C3H6 (v:v=1:99) mixed gas on the crystalline porous organic salt in Example 7, and the mixed gas flow rate is 2 mL / min;

[0043] Figure 7 This is a flow chart of the self-repairing process of the crystalline porous organic salt in Example 8;

[0044] Figure 8 This is a comparison diagram of the PXRD curves of the self-repaired crystalline porous organic salt and the originally synthesized crystalline porous organic salt in Example 9;

[0045] Fig. 9This is a comparison diagram of the single-component adsorption isotherms of carbon dioxide between the self-repaired crystalline porous organic salt in Example 10 and the originally synthesized crystalline porous organic salt under the conditions of 273K and 0-100kPa. DETAILED DESCRIPTION

[0046] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0047] Embodiment 1:

[0048] 342.4 mg of 4,4',4",4"-methanetetrayltetrabenzenesulfonic acid (CAS No.: 1042222-34-3) was dissolved in 48.0 mL of methanol, and 91.2 mg of trans-1,4-cyclohexanediamine (CAS No.: 2615-25-0) was dissolved in 48.0 mL of methanol. Then, the methanol solution of trans-1,4-cyclohexanediamine was added to the methanol solution of 4,4',4",4"-methanetetrayltetrabenzenesulfonic acid, and the mixture was allowed to stand overnight to obtain a light yellow crystalline porous organic salt CPOS-1 sample with charge separation confined pores, with a yield of 80%.

[0049] Embodiment 2:

[0050] In order to test the stability of the sample, the CPOS-1 sample obtained in Example 1 was exposed to humid air or immersed in water for 2 weeks before being subjected to a powder X-ray diffraction test. The measured PXRD curve is as follows: Figure 1 As shown, the PXRD curves of the samples, whether exposed to air or immersed in water for 2 weeks, are consistent with those of the newly synthesized ones, indicating that the material has good stability.

[0051] Embodiment 3:

[0052] About 100 mg of CPOS-1 sample obtained in Example 1 was placed in an adsorption tube, and after vacuuming at room temperature for two hours, it was activated by vacuuming at 120°C for 10 hours. Then, under the condition of a dry ice / isopropanol bath, the activated sample was subjected to a 195K carbon dioxide adsorption and desorption test using an adsorption instrument to test its permanent porosity and calculate its pore volume to be 0.142 cm 3 / g.

[0053] Embodiment 4:

[0054] Under the condition of 273K (ethanol bath), the activated CPOS-1 sample in Example 3 was subjected to carbon dioxide adsorption and desorption test using an adsorption instrument, and the BET specific surface area of ​​the material was calculated based on the test results to be 256.6 cm 3 / g.

[0055] Embodiment 5:

[0056] Under the conditions of 278K, 298K and 308K, the activated CPOS-1 sample in Example 3 was subjected to single-component gas adsorption experiments of acetylene, ethylene, propyne and propylene using an adsorption instrument, and its single-component gas adsorption curves were determined as follows: Figure 2 and Figure 3 Specifically, at 298K and 100kPa, the adsorption capacity of acetylene and propyne of CPOS-1 can reach 40.3 and 39.4 cm 3 / g, and the bulk density reaches 0.33 and 0.50 g / cm 3 , which is equivalent to 71% and 78% of liquid acetylene and propyne at 0°C. At this time, the adsorption of ethylene and propylene is only 26.1 and 27.0 cm 3 At 298K and ultra-low pressure of 1kPa, the adsorption capacity of acetylene and propyne of CPOS-1 can reach 18.4 and 20.9 cm 3 / g, indicating that the material has a very strong affinity for alkynes.

[0057] Embodiment 6:

[0058] The dual-site Langmuir and dual-site Langmuir-Freundlich models were used to fit the single-component acetylene, ethylene, propyne, and propylene gas adsorption isotherms of CPOS-1. Then, the fitting parameters and the ideal solution adsorption theory (IAST) were used to calculate the separation selectivity of CPOS-1 for acetylene / ethylene and propyne / propylene mixed gases with a molar ratio of 1:99 at 298K and 100kPa to be 25.1 and 43.9, respectively. This shows that CPOS-1 can achieve the removal of trace acetylene and propyne. The selectivity curve is shown in Figure 2. Figure 4 Then, the adsorption heat curve of CPOS-1 was calculated using the fitted parameters and the Clausius-Clapeyron equation. The adsorption heat of CPOS-1 for acetylene, ethylene, propyne, and propylene is 38.2, 28.4, 44.2, and 31.6 kJ / mol, respectively.

[0059] Embodiment 7:

[0060] The CPOS-1 material obtained in Example 1 was ground into fine powder of uniform size, loaded into an adsorption column with an inner diameter of 0.5 cm and a length of 5 cm, and activated at 120°C for 10 hours. At room temperature of 25°C, a mixture of acetylene / ethylene (1 / 99, v / v) or propyne / propylene (1 / 99, v / v) was introduced into the adsorption column at a rate of 2 mL / min. The results are shown in FIG. Figure 5 and Figure 6 As shown, it can be observed that ethylene or propylene gas penetrates out first, and acetylene or propyne gas comes out after a certain period of time.

[0061] Embodiment 8:

[0062] About 100 mg of CPOS-1 material obtained in Example 1 was placed under ultraviolet light for one week to destroy its framework structure, and then dissolved in 1 mL of dimethyl sulfoxide (DMSO) at 35°C, and then 3 mL of ethanol was added to the above solution to obtain a self-repaired light yellow powder sample with a yield of 81%. The self-repair process is as follows Figure 7 shown.

[0063] Embodiment 9:

[0064] The self-repaired CPOS-1 material obtained in Example 8 was subjected to a powder X-ray diffraction test, and the measured PXRD curve was as follows: Figure 8 As shown, it is consistent with that just synthesized, verifying that the structure of the self-healing material is consistent with the original framework.

[0065] Embodiment 10:

[0066] The self-repaired CPOS-1 material obtained in Example 8 was placed in an adsorption tube, and after vacuuming at room temperature for two hours, it was activated by vacuuming at 120°C for 10 hours. Then, the activated sample was subjected to a 273K carbon dioxide adsorption and desorption test using an adsorption instrument under an ethanol bath, and the adsorption isotherm was compared with that of the original sample under the same conditions. The results are shown in FIG. Fig. 9 As shown, the successful self-repair of the material was further verified.

[0067] In addition, it should be understood that after reading the above description of the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A method for separating alkynes with the same carbon number, characterized in that: include: The mixed fluid containing alkynes and alkenes with the same carbon number is contacted with a crystalline porous organic salt having charge separation confined pores, wherein the crystalline porous organic salt selectively adsorbs alkynes in the mixed fluid to achieve separation of alkynes and alkenes with the same carbon number; The molecular formula of the crystalline porous organic salt is (C 25 H 16 S4O 12 )(C6H 16 N2)2, having 4,4',4",4"-methanetetrayltetrabenzenesulfonate (C 25 H 16 S4O 12 ) 4- With trans-1,4-cyclohexanediamine cation (C6H 16 N2)2 2+ The three-dimensional structure is formed by intermolecular ionic bonds, wherein a single 4,4',4",4"-methanetetrayltetrabenzenesulfonate is connected to four adjacent trans-1,4-cyclohexanediamine cations via 12 NH·…·OS ionic bonds.

2. The method for separating alkynes with the same carbon number according to claim 1, characterized in that: The alkyne and olefin with the same carbon number are acetylene and ethylene, or propyne and propylene; The crystalline porous organic salt has ultra-microporous periodic one-dimensional pores, and the pore size is 3. The method for separating alkynes with the same carbon number as claimed in claim 1, characterized in that: In the mixed fluid, based on the total molar amount of alkynes and olefins as 100%, the molar content of alkynes is between 1% and 70%, and can further be between 1% and 10%.

4. The method for separating alkynes with the same carbon number as claimed in claim 1, characterized in that: The contact mode of the mixed fluid and the crystalline porous organic salt is any one or more combinations of fixed bed adsorption, fluidized bed adsorption and moving bed adsorption.

5. The method for separating alkynes with the same carbon number as claimed in claim 1, characterized in that: The contact mode between the mixed fluid and the crystalline porous organic salt is fixed bed adsorption, including: under set adsorption temperature and pressure, the mixed fluid enters a fixed bed adsorption column filled with the crystalline porous organic salt at a set flow rate, the olefin component preferentially penetrates the bed layer, and a high-purity olefin component is directly obtained from the outlet of the adsorption column.

6. The method for separating alkynes with the same carbon number as claimed in claim 1, characterized in that: The adsorption temperature is 0-40° C., and the adsorption pressure is 0.5-10 atm.

7. The method for separating alkynes with the same carbon number as claimed in claim 1, characterized in that: The method for separating alkynes with the same carbon number also includes: after separation of alkynes with the same carbon number, desorbing alkynes at a temperature of 60 to 120° C. and a pressure of 0 to 1 atm to regenerate the crystalline porous organic salt.

8. Use of a crystalline porous organic salt having charge separation confined pores in the separation of alkynes and alkenes with the same carbon number, characterized in that: The crystalline porous organic salt selectively adsorbs the alkynes in the mixed fluid after contacting with the mixed fluid containing alkynes and alkenes with the same carbon number, thereby achieving separation of alkynes and alkenes with the same carbon number; The molecular formula of the crystalline porous organic salt is (C 25 H 16 S4O 12 )(C6H 16 N2)2, having 4,4',4",4"-methanetetrayltetrabenzenesulfonate (C 25 H 16 S4O 12 ) 4- With trans-1,4-cyclohexanediamine cation (C6H 16 N2)2 2+ The three-dimensional structure is formed by intermolecular ionic bonds, wherein a single 4,4',4",4"-methanetetrayltetrabenzenesulfonate is connected to four adjacent trans-1,4-cyclohexanediamine cations via 12 NH·…·OS ionic bonds.

9. The use according to claim 8, characterized in that: The alkyne and olefin with the same carbon number are acetylene and ethylene, or propyne and propylene; The crystalline porous organic salt has ultra-microporous periodic one-dimensional pores, and the pore size is 10. The use according to claim 8, characterized in that: In the mixed fluid, the molar content of alkyne is between 1% and 70%, and can further be between 1% and 10%, based on the total molar amount of alkyne and olefin as 100%. The contacting mode of the mixed fluid and the crystalline porous organic salt is any one or more combinations of fixed bed adsorption, fluidized bed adsorption and moving bed adsorption; The adsorption temperature is 0-40° C., and the adsorption pressure is 0.5-10 atm.

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