Adsorbent for separating ethylene from ethane, preparation method thereof and method for concentrating ethylene

Abstract

The invention relates to an adsorbent for ethylene and ethane separation, a preparation method thereof and a method for applying the adsorbent to ethylene concentration, the adsorbent comprises a metal modified molecular sieve, a binder and an auxiliary agent, the metal modified molecular sieve comprises an A type molecular sieve and a metal ion active component, the metal ion active component comprises a component M1 and a component M2, and the component M1 and the component M2 are different from each other. The metal-modified molecular sieve meets the formula (1): K is 0.92-1.0, xM1 and xM2 are the valence of the component M1 and the valence of the component M2 respectively, nM1, nM2 and nNa are the mole numbers of sodium ions in the component M1, the component M2 and the A-type molecular sieve respectively, the mole numbers are all obtained through an X-ray fluorescence spectrum, and in terms of mole, x is greater than or equal to 1 and less than or equal to 1. The adsorbent can well separate ethylene from mixed gas of ethylene and ethane, and high-concentration ethylene gas is obtained.

Description

Technical Field

[0001] This invention relates to adsorbents and methods for preparing adsorbents, as well as methods for concentrating ethylene, and more specifically to adsorbents for separating ethylene and ethane and methods for preparing the adsorbents, and also to a method for concentrating ethylene. Background Technology

[0002] Ethylene is a crucial raw material in modern petrochemicals, and its production volume and technological level can be used to measure the development level of the petrochemical industry. The main ethylene production processes include steam cracking, olefin production as a byproduct of oil refining, methanol-to-olefins (MTO), and ethane dehydrogenation. In these processes, due to the similar physicochemical properties of ethylene and ethane molecules, separating them to obtain high-purity ethylene is very challenging. Currently, cryogenic separation is used industrially to separate ethylene and ethane, but this method requires harsh operating conditions and consumes a lot of energy.

[0003] Adsorption separation is characterized by low energy consumption, low cost, and simple operation, and can obtain ethylene with high purity, making it a highly efficient and low-consumption method for ethylene / ethane separation. In adsorption separation, the adsorption material used is crucial for achieving good separation of ethylene and ethane. Existing materials commonly used for the adsorption separation of ethylene and ethane include carbon materials, MOFs, COFs, and molecular sieves. Among these, molecular sieves have attracted much attention due to their regular and uniform pore structure, adjustable pore size, and especially the exchangeability of their internal cations (e.g., sodium ions). By exchanging the cations inside the molecular sieve with other cations, the separation effect of the molecular sieve from the ethylene and ethane mixture can be improved. Therefore, strategies are needed to obtain materials with improved ethylene and ethane separation performance. Summary of the Invention

[0004] One objective of this invention is to provide an adsorbent for the separation of ethylene and ethane, which has improved ethylene adsorption capacity and improved ethylene adsorption selectivity; another objective of this invention is to provide a method for preparing an adsorbent that is simple to operate, low in cost, highly operable, and has strong prospects for industrial application; a third objective of this invention is to provide a method for concentrating ethylene, which can better separate ethylene from a mixture of ethylene and ethane gases and obtain high-concentration ethylene gas.

[0005] To achieve one of the above objectives, a first aspect of this application provides an adsorbent for the separation of ethylene and ethane, the adsorbent comprising a metal-modified molecular sieve, a binder, and an additive, wherein the metal-modified molecular sieve comprises a type A molecular sieve and a metal ion active component, the metal ion active component comprising component M1 and component M2, and the metal-modified molecular sieve satisfies the following formula (1):

[0006] K is 0.92 to 1.0, preferably 0.95-1.0, more preferably 0.98-1.0, in formula (1),

[0007] x M1 The valence of the metal ion active component M1 is given.

[0008] n M1 The molar number of the metal ion active component M1.

[0009] x M2 The valence of the metal ion active component M2 is given.

[0010] n M2 The molar number of the metal ion active component M2.

[0011] n Na The molar number of sodium ions in the type A molecular sieve.

[0012] The molar numbers of the metal ion active component M1, the metal ion active component M2, and the sodium ions in the type A molecular sieve were all obtained by X-ray fluorescence spectroscopy and expressed in moles.

[0013] Therefore, compared with the prior art, the adsorbent of this application has improved ethylene adsorption capacity and improved ethylene adsorption selectivity, which can better separate ethylene from the mixture of ethylene and ethane to obtain high concentration of ethylene gas.

[0014] In any embodiment of this application, the metal ion active component M1 is selected from Mg 2+ Ca 2+ and Sr 2+ At least one of the following; the metal ion active component M2 is selected from Ag. + Cu 2+ Zn 2+ Mn 2+ Ni 2+ Co 2+ Cd 2+ Fe 2+ Fe 3+ and Cr 3+ At least one of them, preferably selected from Ag + Zn 2+ Mn 2+ Fe 2+ and Co 2+ At least one of them.

[0015] In any embodiment of this application, in the metal-modified molecular sieve, x M1 nM1 ·x M2 n M2 / (x M1 n M1 +x M2 n M2 The value is 0.172-0.245, preferably 0.200-0.215.

[0016] In any embodiment of this application, the binder is sodium aluminate, sodium silicate, or a combination thereof.

[0017] In any embodiment of this application, the adjuvant is selected from at least one of guar gum powder, lignin, and sodium cellulose.

[0018] In any embodiment of this application, the weight ratio of the metal-modified molecular sieve, binder and additive is 1:0.02-0.10:0.01-0.03, preferably 1:0.04-0.06:0.02-0.03.

[0019] To achieve the second objective mentioned above, a second aspect of this application provides a method for preparing the adsorbent for the separation of ethylene and ethane as described in the first aspect of this application. The method comprises: mixing a metal-modified molecular sieve with a binder and additives, followed by spherical molding, drying, and calcination to obtain a spherical adsorbent.

[0020] The metal-modified molecular sieve is obtained through the following steps:

[0021] S1) Ion exchange is performed between type A molecular sieve powder and a solution containing a salt of metal ion active component M1 at an apparent pressure of 0.2-1 MPa and a temperature of 50-95℃; and

[0022] S2) The product obtained in step S1) is subjected to ion exchange with a solution of salt containing the active metal ion component M2 at an apparent pressure of 0.2-1 MPa and a temperature of 50-95 °C.

[0023] Therefore, compared with the prior art, the preparation method of this application is simple to operate, low in cost, and highly operable, and has strong prospects for industrial application. This preparation method can obtain an adsorbent with improved ethylene adsorption capacity and improved ethylene adsorption selectivity, thereby enabling better separation of ethylene from a mixture of ethylene and ethane gases to obtain high-concentration ethylene gas.

[0024] In any embodiment of this application, the apparent pressure is 0.3-0.9 MPa, preferably 0.4-0.8 MPa, more preferably 0.5-0.7 MPa, and most preferably 0.55-0.65 MPa; and the temperature is 60-90°C, preferably 80-90°C.

[0025] In any embodiment of this application, the salt containing the metal ion active component M1 is a chloride, nitrate, sulfate, or acetate containing the metal ion active component M1, and the metal ion active component M1 is selected from Mg 2+ Ca 2+ and Sr 2+ At least one of the following; the salt containing the metal ion active component M2 is a chloride, nitrate, sulfate, or acetate containing the metal ion active component M2, and the metal ion active component M2 is selected from Ag. + Cu 2+ Zn 2+ Mn 2+ Ni 2+ Co 2+ Cd 2+ Fe 2+ Fe 3+ and Cr 3+ At least one of them, preferably selected from Ag + Zn 2+ Mn 2+ Fe 2+ and Co 2+ At least one of them.

[0026] In any embodiment of this application, the weight ratio of the type A molecular sieve raw powder to the salt containing the metal ion active component M1 and the salt containing the metal ion active component M2 is 1:0.8-1.5:0.2-0.6, preferably 1:1-1.5:0.2-0.45.

[0027] In any embodiment of this application, the apparent pressure is obtained by hydrothermal pressurization or ventilated pressurization, preferably by ventilated pressurization.

[0028] In any embodiment of this application, the apparent pressure is 0.55-0.65 MPa and is obtained by pressurizing by ventilation, and the temperature is 80-90°C.

[0029] In any embodiment of this application, the binder is sodium aluminate, sodium silicate, or a combination thereof.

[0030] In any embodiment of this application, the adjuvant is selected from at least one of guar gum powder, lignin, and sodium cellulose.

[0031] In any embodiment of this application, the weight ratio of the metal-modified molecular sieve, binder and additive is 1:0.02-0.10:0.01-0.03, preferably 1:0.04-0.06:0.02-0.03.

[0032] To achieve the third objective mentioned above, a third aspect of this application provides a method for concentrating ethylene, the method comprising the following steps:

[0033] 1) Activate the adsorbent of the first aspect of this application or the adsorbent obtained by the method of the second aspect of this application to obtain an activated adsorbent;

[0034] 2) Selective adsorption is performed by contacting a mixed gas of ethylene and ethane with a bed of activated adsorbent, wherein the adsorption temperature is 10-40℃, preferably 20-30℃, and the adsorption pressure is 0.5-1.0MPa, preferably 0.6-0.8MPa;

[0035] 3) The gas adsorbed on the desorbent has a desorption temperature of 80-200℃ and a desorption pressure of 0.001-0.1MPa, preferably 0.005-0.08MPa.

[0036] Therefore, the ethylene concentration method of this application can obtain high-concentration ethylene gas, and can separate high-value ethylene from the ethylene and ethane mixture, which can be used to produce high-value chemical raw materials. Moreover, the ethylene concentration method of this application can be applied at lower temperatures and lower pressures, and the operation process is simple, energy consumption is low and operating costs are low, which has strong prospects for industrial application.

[0037] In any embodiment of this application, in step 1), the activation temperature is 150-450°C, preferably 200-400°C, the activation time is 30-180 min, preferably 60-150 min, and the activation is carried out in an atmosphere of nitrogen, argon or helium.

[0038] In any embodiment of this application, in step 2), the mass hourly space velocity (MSV) of the ethylene and ethane mixture is 0.3-3 h⁻¹. -1 Preferably, it is 1.0-2.0h. -1 .

[0039] In any embodiment of this application, in step 2), the mixed gas of ethylene and ethane is contacted with the bed of activated adsorbent in a fixed-bed adsorption or simulated moving-bed adsorption manner. Detailed Implementation

[0040] The following describes in detail the embodiments of the adsorbent for the separation of ethylene and ethane, its preparation method, and the method for concentrating ethylene. However, unnecessary details may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of practically identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0041] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0042] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0043] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0044] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0045] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0046] The first aspect of this application provides an adsorbent for the separation of ethylene and ethane, the adsorbent comprising a metal-modified molecular sieve, a binder, and an additive, wherein the metal-modified molecular sieve comprises a type A molecular sieve and a metal ion active component, the metal ion active component comprising component M1 and component M2, and the metal-modified molecular sieve satisfies the following formula (1):

[0047]

[0048] K is 0.92 to 1.0, preferably 0.95-1.0, and more preferably 0.98-1.0.

[0049] in,

[0050] x M1 The valence of the metal ion active component M1 is given.

[0051] n M1 The molar number of the metal ion active component M1.

[0052] x M2 The valence of the metal ion active component M2 is given.

[0053] n M2 The molar number of the metal ion active component M2.

[0054] n Na The molar number of sodium ions in the type A molecular sieve.

[0055] The molar numbers of the metal ion active component M1, the metal ion active component M2, and the sodium ions in the type A molecular sieve were all obtained by X-ray fluorescence spectroscopy and expressed in moles.

[0056] Although the mechanism is not yet clear, the applicant has unexpectedly discovered that the adsorbent for the separation of ethylene and ethane in this application contains a specific metal-modified molecular sieve—comprising a metal ion active component M1 and a metal ion active component M2. The metal ion active component M1 modulates the pore size of the molecular sieve to a position between the kinetic diameters of ethylene and ethane (the metal ion active component M1 can regulate the pore size of the type A molecular sieve, but there is almost no interaction between it and ethylene molecules). The metal ion active component M2 can form a π-complex with ethylene (the metal ion active component M2 can serve as an active site for ethylene adsorption), thereby improving the interaction between the molecular sieve and ethylene. Furthermore, the K value, which reflects the relationship between components M1, M2, and sodium ions in the molecular sieve, is within a specific range—thus enabling the adsorbent of this application to have improved ethylene adsorption capacity and ethylene adsorption selectivity, achieving good separation of ethylene from the mixture of ethylene and ethane to obtain a high concentration of ethylene gas.

[0057] In this application, the molar numbers of sodium ions, metal ion active component M1, and metal ion active component M2 in the type A molecular sieve are all obtained by X-ray fluorescence spectroscopy, expressed in moles. For example, a ZSX100E X-ray fluorescence spectrometer manufactured by Rigaku Corporation of Japan was used with an excitation voltage of 40 kV and an excitation current of 250 mA to test the molar numbers of sodium ions, metal ion active component M1, and metal ion active component M2 in the type A molecular sieve.

[0058] In this application, the valence x of the metal ion active component M1 is... M1 and the valence x of the metal ion active component M2 M2 All are positive numbers. For example, when the active metal ion component M1 is Ca... 2+ When, the x M1 The value is 2. When the active metal ion component M2 is Ag... + When, the x M2 The value is 1; when the active metal ion component M2 is Fe 3+ When, the x M2 The value is 3. In some embodiments, x is... M1 The value is 2.

[0059] In some embodiments, the metal-modified molecular sieve satisfies a K value of 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, or 1.0 in formula (1). Therefore, the adsorbent of this application containing molecular sieves with K values ​​within a specific range exhibits improved ethylene adsorption capacity and ethylene adsorption selectivity.

[0060] In some embodiments, the metal ion active component M1 is selected from Mg2+ Ca 2+ and Sr 2+ At least one of the following; the metal ion active component M2 is selected from Ag. + Cu 2+ Zn 2+ Mn 2+ Ni 2+ Co 2+ Cd 2+ Fe 2+ Fe 3+ and Cr 3+ At least one of them, preferably selected from Ag + Zn 2+ Mn 2+ Fe 2+ and Co 2+ At least one of them.

[0061] In some embodiments, the metal ion active component M1 is selected from Mg 2+ Ca 2+ and Sr 2+ One of them; and the metal ion active component M2 is selected from Ag. + Cu 2+ Zn 2+ Mn 2+ Ni 2+ Co 2+ Cd 2+ Fe 2+ Fe 3+ and Cr 3+ One of them, preferably selected from Ag + Zn 2+ Mn 2+ Fe 2+ and Co 2+ One of them.

[0062] In some embodiments, when the metal ion active component M1 is selected from Mg 2+ Ca 2+ and Sr 2+ When there are two possibilities, then x in equation (1) M1 n M1 The value is the sum of the products of the valence and the molar number of each of the two metal ions. For example, when the active component M1 of the metal ions is Mg... 2+ and Ca 2+ When, then x in equation (1) M1 n M1The value is the product of the valence of magnesium ions and their corresponding molar number, plus the product of the valence of calcium ions and their corresponding molar number. In some embodiments, when the active metal ion component M2 is selected from Ag... + Cu 2+ Zn 2+ Mn 2+ Ni 2+ Co 2+ Cd 2+ Fe 2+ Fe 3+ and Cr 3+ Two of them, preferably selected from Ag + Zn 2+ Mn 2+ Fe 2+ and Co 2+ When there are two possibilities, then x in equation (1) M2 n M2 The value is the sum of the products of the valence of each of the two metal ions and their corresponding molar number. For example, when the active component M2 of the metal ions is Ag... + and Zn 2+ When, then x in equation (1) M2 n M2 The value is the product of the valence of silver ions and their corresponding molar number, plus the product of the valence of zinc ions and their corresponding molar number.

[0063] In some embodiments, in the metal-modified molecular sieve, x M1 n M1 ·x M2 n M2 / (x M1 n M1 +x M2 n M2 The value is 0.172-0.245, preferably 0.200-0.215. When the components M1 and M2 in the metal-modified molecular sieve satisfy a specific ratio, i.e., x M1 n M1 ·x M2 n M2 / (x M1 n M1 +x M2 n M2 When the value of ) is within a specific range, the adsorbent of this application can effectively separate ethylene from the mixture of ethylene and ethane to obtain a high concentration of ethylene gas.

[0064] In some embodiments, the binder is sodium aluminate, sodium silicate, or a combination thereof.

[0065] In some embodiments, the adjuvant is selected from at least one of guar gum powder, lignin, and sodium cellulose.

[0066] In some embodiments, the weight ratio of the metal-modified molecular sieve, binder, and additive is 1:0.02-0.10:0.01-0.03, preferably 1:0.04-0.06:0.02-0.03.

[0067] This application also provides a method for preparing an adsorbent for the separation of ethylene and ethane according to the first aspect of this application, the method comprising: mixing a metal-modified molecular sieve with a binder and an additive, and then subjecting the mixture to spherical molding, drying, and calcination to obtain a spherical adsorbent.

[0068] The metal-modified molecular sieve is obtained through the following steps:

[0069] S1) Ion exchange is carried out between the type A molecular sieve raw powder and a solution containing a salt of metal ion active component M1 at an apparent pressure of 0.2-1.0 MPa and a temperature of 50-95℃.

[0070] S2) The product obtained in step S1) is subjected to ion exchange with a solution of salt containing the active metal ion component M2 at an apparent pressure of 0.2-1 MPa and a temperature of 50-95 °C.

[0071] Although the mechanism is not yet clear, the applicant unexpectedly discovered that by using a specific metal-modified molecular sieve—firstly, by exchanging the raw A-type molecular sieve powder with a salt containing the metal ion active component M1 under the synergistic effect of specific apparent pressure and temperature—it is possible to promote the migration of more of the metal ion active component M1 into the pores of the A-type molecular sieve, where it exchanges with the sodium ions originally present in the sodalite cages of the A-type molecular sieve, replacing some of the sodium ions in the sodalite cages with the metal ion active component M1, thereby modulating the pore size of the molecular sieve to between the kinetic diameters of ethylene and ethane; subsequently, the A-type molecular sieve after the metal ion active component M1 exchange is exchanged with a salt containing the metal ion active component M2 under specific apparent pressure. Ion exchange occurs under the synergistic effect of force and temperature, causing sodium ions in the type A molecular sieve to be further replaced by the active metal ion component M2 (while a small amount of active metal ion component M1 is also replaced by active metal ion component M2). The active metal ion component M2 can form a π-complex with ethylene, thereby creating more active sites for ethylene adsorption inside the type A molecular sieve. At the same time, the components M1, M2 and sodium ions in this molecular sieve satisfy a specific ratio relationship (i.e., the K value in equation (1) is within a specific range) - which can obtain an adsorbent with improved ethylene adsorption capacity and ethylene adsorption selectivity, so as to achieve good separation of ethylene from the mixture of ethylene and ethane gas and obtain high concentration of ethylene gas. At the same time, this method is simple, low-cost and highly operable, and has strong industrial application prospects.

[0072] In this application, all cations in the type A molecular sieve raw powder are sodium ions, that is, all cations originally present in the type A molecular sieve are sodium ions. The type A molecular sieve raw powder is commercially available, for example, purchased from the catalyst factory of Nankai University; or optionally, it can be obtained by preparation methods known to those skilled in the art (for example, as described in "Molecular Sieves and Porous Materials Chemistry", Xu Ruren, Pang Wenqin, Huo Qisheng, et al., Science Press, 2nd edition, August 2014, Chapter 3 "Synthetic Chemistry of Microporous Compounds (Part 1) - Basic Laws and Synthetic Routes", pages 158-159).

[0073] Optionally, in step S1), the product obtained after ion exchange is filtered, washed, and dried.

[0074] Optionally, in step S2), the product obtained after ion exchange is filtered, washed, and dried.

[0075] In this application, the apparent pressure and temperature used in step S1) during ion exchange can be the same as or different from the apparent pressure and temperature used in step S2) during ion exchange, preferably the same. For example, in step S1), the type A molecular sieve powder is ion exchanged with a solution containing a salt of metal ion active component M1 at an apparent pressure of 0.6 MPa and a temperature of 90°C; and in step S2), the product obtained in step S1) is ion exchanged with a solution containing a salt of metal ion active component M2 at an apparent pressure of 0.6 MPa and a temperature of 90°C.

[0076] In some embodiments, the ion exchange in step S1) and / or step S2) is performed at an apparent pressure of 0.2 MPa, 0.25 MPa, 0.3 MPa, 0.35 MPa, 0.4 MPa, 0.45 MPa, 0.5 MPa, 0.55 MPa, 0.6 MPa, 0.65 MPa, 0.7 MPa, 0.75 MPa, 0.8 MPa, 0.85 MPa, 0.9 MPa, 0.95 MPa, or 1 MPa, preferably at the same apparent pressure for both step S1) and step S2).

[0077] In some embodiments, the ion exchange in step S1) and / or step S2) is carried out at a temperature of 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C or 95°C, preferably at the same temperature for step S1) and step S2).

[0078] In some embodiments, the ion exchange in step S1) and / or step S2) is performed at an apparent pressure of 0.2 MPa, 0.25 MPa, 0.3 MPa, 0.35 MPa, 0.4 MPa, 0.45 MPa, 0.5 MPa, 0.55 MPa, 0.6 MPa, 0.65 MPa, 0.7 MPa, 0.75 MPa, 0.8 MPa, 0.85 MPa, 0.9 MPa, 0.95 MPa, or 1 MPa, while simultaneously at a temperature of 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, or 95°C. Preferably, the apparent pressure and temperature of the ion exchange in steps S1) and S2) are the same.

[0079] In some embodiments, the apparent pressure of step S1) and / or step S2) is 0.3-0.9 MPa, preferably 0.4-0.8 MPa, more preferably 0.5-0.7 MPa and most preferably 0.55-0.65 MPa; and the temperature is 60-90°C, preferably 80-90°C.

[0080] In some embodiments, the salt containing the metal ion active component M1 is a chloride, nitrate, sulfate, or acetate containing the metal ion active component M1, and the metal ion active component M1 is selected from Mg. 2+ Ca 2+ and Sr 2 + At least one of the following; the salt containing the metal ion active component M2 is a chloride, nitrate, sulfate, or acetate containing the metal ion active component M2, and the metal ion active component M2 is selected from Ag. + Cu 2+ Zn 2+ Mn 2+ Ni 2+ Co 2+ Cd 2+ Fe 2+ Fe 3+ and Cr 3+ At least one of them, preferably selected from Ag + Zn 2+ Mn 2+ Fe 2+ and Co 2+ At least one of them.

[0081] In some embodiments, the metal ion active component M1 is selected from Mg 2+ Ca 2+ and Sr 2+ One of them; and the metal ion active component M2 is selected from Ag. + Cu 2+ Zn 2+ Mn 2+ Ni 2+ Co 2+ Cd 2+ Fe 2+ Fe 3+ and Cr 3+ One of them, preferably selected from Ag + Zn 2+ Mn 2+ Fe 2+ and Co 2+ One of them.

[0082] In some embodiments, the weight ratio of the type A molecular sieve raw powder to the salt containing the metal ion active component M1 and the salt containing the metal ion active component M2 is 1:0.8-1.5:0.2-0.6, preferably 1:1-1.5:0.2-0.45.

[0083] In some embodiments, the apparent pressure is obtained by hydrothermal pressurization or ventilated pressurization, preferably by ventilated pressurization.

[0084] In some embodiments, the ion exchange is carried out at an apparent pressure of 0.2-1 MPa by hydrothermal pressurization or aeration pressurization, preferably by aeration pressurization. In the context of this application, aeration pressurization refers to maintaining the ion exchange process at a certain apparent pressure by introducing gas from the outside. Hydrothermal pressurization refers to maintaining the ion exchange process at a certain apparent pressure by introducing water vapor from the outside. In the context of this application, apparent pressure refers to the pressure value displayed on an external pressure detection device (e.g., a pressure gauge) directly connected to the apparatus for ion exchange. The apparent pressure can be obtained, for example, by loading the raw materials into the reaction apparatus and sealing it, then opening the inlet valve on the reaction apparatus to allow nitrogen gas to enter the reaction apparatus through the inlet port, monitoring the pressure inside the reaction apparatus using a pressure gauge (digital display) connected to the reaction apparatus, and stopping the aeration when the pressure reaches the desired value.

[0085] In some embodiments, when the apparent pressure is obtained by venting and pressurizing, the gas used in the venting and pressurizing is an inert gas, such as nitrogen, argon or helium.

[0086] In any embodiment, the apparent pressure is 0.55-0.65 MPa and is obtained by pressurizing by ventilation, and the temperature is 80-90°C.

[0087] In the preparation of this specific metal-modified molecular sieve, if the apparent pressure and / or temperature during ion exchange is too low, the degree of ion exchange will be low, resulting in fewer active sites for ethylene adsorption. If the apparent pressure and / or temperature during ion exchange is too high, it will damage the crystal structure of the molecular sieve and greatly increase production energy consumption and production costs.

[0088] In some embodiments, the ion exchange time is 30-120 min, preferably 60-90 min.

[0089] In some embodiments, the apparent pressure is 0.55-0.65 MPa and is achieved by pressurization via air circulation, and the temperature is 80-90°C. This improves the degree of ion exchange, modulates the pore size of the type A molecular sieve to the desired size, and simultaneously forms more active sites within the molecular sieve. This results in increased ethylene adsorption capacity and selectivity of the modified molecular sieve, thereby effectively separating ethylene from the ethylene and ethane mixture to obtain more ethylene gas.

[0090] In one preferred embodiment, the metal-modified molecular sieve exhibits an ethylene adsorption capacity of up to 3.30 mmol / g and an ethylene adsorption selectivity of 17.29 in a 1:1 volume ratio of ethylene to ethane mixture. In another preferred embodiment, the metal-modified molecular sieve exhibits an ethylene adsorption capacity of up to 3.66 mmol / g and an ethylene adsorption selectivity of up to 37.03 in a 1:1 volume ratio of ethylene to ethane mixture.

[0091] In some embodiments, the method includes uniformly mixing the metal-modified molecular sieve with a binder and additives to form a mixed powder, placing it in a coating pan while continuously spraying deionized water, and then, by weight, sphericalizing, drying, and calcining the mixed powder to obtain spherical adsorbents with a particle size of 0.3-0.6 mm. In some embodiments, the calcination temperature is 500-600°C, and the calcination time is 3-6 hours.

[0092] In some embodiments, the binder is sodium aluminate, sodium silicate, or a combination thereof.

[0093] In some embodiments, the adjuvant is selected from at least one of guar gum powder, lignin, and sodium cellulose.

[0094] In some embodiments, the weight ratio of the metal-modified molecular sieve, binder, and additive is 1:0.02-0.10:0.01-0.03, preferably 1:0.04-0.06:0.02-0.03.

[0095] This application further provides a method for concentrating ethylene, the method comprising the following steps:

[0096] 1) Activate the adsorbent of the first aspect of this application or the adsorbent obtained by the method of the second aspect of this application to obtain an activated adsorbent;

[0097] 2) Selective adsorption is performed by contacting a mixed gas of ethylene and ethane with a bed of activated adsorbent, wherein the adsorption temperature is 10-40℃, preferably 20-30℃, and the adsorption pressure is 0.5-1.0MPa, preferably 0.6-0.8MPa;

[0098] 3) Desorb the gas adsorbed on the adsorbent at a temperature of 80-200℃ and a desorption pressure of 0.001-0.1MPa, preferably 0.005-0.08MPa.

[0099] Therefore, the method for concentrating ethylene in this application can obtain high-concentration ethylene gas, enabling the separation of high-value ethylene from a mixture of ethylene and ethane gas. This ethylene can be used to produce high-value chemical raw materials. Furthermore, the method of this application can be applied at lower temperatures and pressures, and the operation process is simple, energy consumption is low, and operating costs are low, showing strong prospects for industrial application.

[0100] In some embodiments, in step 1), the activation temperature is 150-450°C, preferably 200-400°C, the activation time is 30-180 min, preferably 60-150 min, and the activation is carried out in an atmosphere of nitrogen, argon, or helium.

[0101] In some embodiments, in step 2), the mass hourly space velocity (MSV) of the ethylene and ethane mixture is 0.3-3 h⁻¹. -1 Preferably, it is 1.0-2.0h. -1 .

[0102] In some embodiments, in step 2), the ethylene and ethane mixture is contacted with the bed of activated adsorbent via fixed-bed adsorption or simulated moving-bed adsorption.

[0103] In some implementations, the volume fraction of ethylene in the gas after desorption from the adsorbent is determined using an Agilent 7890A gas chromatograph.

[0104] In this application, the definitions within the broadest scope and the preferred definitions can be combined to form new technical solutions, which are also considered to be disclosed in this specification.

[0105] The present application is illustrated by way of examples below, but should not be construed as limiting the scope of the present application.

[0106] Example

[0107] I. Raw materials and reaction apparatus

[0108] Type A molecular sieve raw powder was purchased from the catalyst factory of Nankai University.

[0109] All reagents used for ion exchange modification were chemically pure and purchased from Alfa Aesar, USA.

[0110] Guar sesame powder, lignin, and sodium cellulose were purchased from Sinopec Catalyst Co., Ltd.

[0111] Sodium aluminate and sodium silicate were purchased from Sinopec Catalyst Co., Ltd.

[0112] Ethylene (purity >99.99%) and ethane (99.95%) were purchased from Beijing Huanyu Jinghui Jingcheng Gas Technology Co., Ltd.

[0113] The ion exchange reaction apparatus was purchased from Shanghai Laibei Scientific Instruments Co., Ltd.

[0114] The ball forming device was purchased from Wenling Linda Machinery Co., Ltd.

[0115] II. Determination of the molar number of each cation in the molecular sieve

[0116] First, the molecular sieve sample was pressed into a pellet and placed in a ZSX100E X-ray fluorescence spectrometer manufactured by Rigaku Corporation of Japan. The test was conducted under the conditions of a tungsten target as the X-ray source, an excitation voltage of 40 kV, and an excitation current of 250 mA to obtain the molar number of cations in the molecular sieve (i.e., the molar number of sodium ions, the molar number of metal ion active component M1, and the molar number of metal ion active component M2).

[0117] Example 1

[0118] (1) Preparation of metal-modified molecular sieves

[0119] S1) Mix 4g of 4A molecular sieve, 4g of anhydrous CaCl2 as the salt containing the metal ion active component M1, and 40g of deionized water, load them into the reaction apparatus and seal it. Then open the gas inlet valve on the reaction apparatus to allow nitrogen gas to enter the reaction apparatus through the gas inlet. When the pressure inside the reaction apparatus reaches 0.6MPa, stop the gas supply. Then heat the reaction apparatus to 90℃ and carry out ion exchange for 60min at an apparent pressure of 0.6MPa and a reaction temperature of 90℃. Filter the product and wash it with deionized water until neutral, and dry it at a constant temperature of 70℃.

[0120] S2) Subsequently, 4g of the dried sample was weighed and mixed with 1.751g of Zn(NO3)2·6H2O as the salt containing the metal ion active component M2 and 40g of deionized water. The mixture was placed in a reaction apparatus and sealed. Then, the inlet valve on the reaction apparatus was opened to allow nitrogen gas to enter the reaction apparatus through the inlet. When the pressure inside the reaction apparatus reached 0.6MPa, the gas supply was stopped. The reaction apparatus was then heated to 90℃, and ion exchange was carried out for 60min at an apparent pressure of 0.6MPa and a reaction temperature of 90℃. The product was filtered and washed with deionized water until neutral, and then dried at a constant temperature of 70℃ to obtain a metal-modified molecular sieve for subsequent preparation of an adsorbent for the separation of ethylene and ethane.

[0121] (2) Preparation of adsorbents for the separation of ethylene and ethane

[0122] The metal-modified molecular sieve obtained in (1) above was mixed with sodium aluminate and guar gum powder at a weight ratio of 1:0.05:0.02 to form a mixed powder. The powder was placed in a pelletizing machine and deionized water was sprayed into it while rolling. The pellets were formed into small balls of about 0.5 mm. The pellets were dried at 100°C for 24 h and then calcined at 550°C for 4 h to obtain spherical adsorbents. The preparation parameters of the adsorbent are shown in Table 1.

[0123] (3) Methods for concentrating ethylene from a mixture of ethylene and ethane gases

[0124] The adsorbent obtained in (2) above for the separation of ethylene and ethane was activated at 400°C under a nitrogen atmosphere for 120 min. Subsequently, a mixture of ethylene and ethane, in which ethylene volume fraction was 50%, was subjected to a nitrogen atmosphere at 25°C and 0.8 MPa for 2.0 h. -1 Selective adsorption is achieved by contacting the activated adsorbent bed with a mass hourly space velocity (MHSV) in a fixed bed configuration. The tail gas after passing through the adsorbent bed was monitored using an Agilent 7890A gas chromatograph. Selective adsorption was stopped when an ethylene signal was detected in the tail gas. The temperature of the adsorbent bed was increased to 150°C, and the pressure was reduced to 0.005 MPa to desorb the adsorbed gas. The volume fraction of ethylene in the desorbed gas was determined using the gas chromatograph, and the results are shown in Table 2.

[0125] Example 2

[0126] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1, except that in step S2), 1gAgNO3 is added as a salt containing the metal ion active component M2.

[0127] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0128] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0129] Example 3

[0130] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1, except that: in step S1), ion exchange is carried out at an apparent pressure of 0.55 MPa and a reaction temperature of 90 °C; in step S2), 1.165 g of MnCl2·4H2O is added as a salt containing the active component M2 of metal ions, and ion exchange is carried out at an apparent pressure of 0.55 MPa and a reaction temperature of 90 °C.

[0131] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0132] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0133] Example 4

[0134] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1, except that: in step S1), ion exchange is carried out at an apparent pressure of 0.65 MPa and a reaction temperature of 85 °C; in step S2), 1.713 g of Co(NO3)2·6H2O is added as a salt containing the metal ion active component M2, and ion exchange is carried out at an apparent pressure of 0.65 MPa and a reaction temperature of 85 °C.

[0135] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0136] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0137] Example 5

[0138] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1, except that: in step S1), 5.715g of anhydrous SrCl2 is added as a salt containing metal ion active component M1, and ion exchange is carried out at an apparent pressure of 0.55MPa and a reaction temperature of 95℃; in step S2), 1.17g of FeCl2·4H2O is added as a salt containing metal ion active component M2, and ion exchange is carried out at an apparent pressure of 0.55MPa and a reaction temperature of 95℃.

[0139] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0140] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0141] Example 6

[0142] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1, except that: in step S1), 3.423g of anhydrous MgCl2 is added as a salt containing metal ion active component M1, and ion exchange is carried out at an apparent pressure of 0.6MPa and a reaction temperature of 80℃; in step S2), 2.356g of Cr(NO3)3·9H2O is added as a salt containing metal ion active component M2, and ion exchange is carried out at an apparent pressure of 0.6MPa and a reaction temperature of 80℃.

[0143] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0144] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0145] Example 7

[0146] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 4, except that: both steps S1) and S2) are carried out by ion exchange at an apparent pressure of 0.2 MPa and a reaction temperature of 90 °C.

[0147] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 4. The parameters of the adsorbent preparation method are shown in Table 1.

[0148] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 4. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0149] Example 8

[0150] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 4, except that: both steps S1) and S2) are carried out by ion exchange at an apparent pressure of 1.0 MPa and a reaction temperature of 50 °C.

[0151] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 4. The parameters of the adsorbent preparation method are shown in Table 1.

[0152] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 4. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0153] Example 9

[0154] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 4, except that: both steps S1) and S2) are carried out by ion exchange at an apparent pressure of 0.4 MPa and a reaction temperature of 70 °C.

[0155] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 4. The parameters of the adsorbent preparation method are shown in Table 1.

[0156] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 4. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0157] Example 10

[0158] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 4, except that: both steps S1) and S2) are carried out by ion exchange at an apparent pressure of 0.8 MPa and a reaction temperature of 60 °C.

[0159] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 4. The parameters of the adsorbent preparation method are shown in Table 1.

[0160] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 4. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0161] Example 11

[0162] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 3.

[0163] (2) The preparation method of the adsorbent for the separation of ethylene and ethane is the same as that in Example 3, except that sodium silicate is added as a binder and sodium cellulose as an additive. The metal-modified molecular sieve is mixed with sodium silicate and sodium cellulose in a weight ratio of 1:0.03:0.03 to form a mixed powder. The preparation parameters of the adsorbent are shown in Table 1.

[0164] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 3. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0165] Example 12

[0166] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 3.

[0167] (2) The preparation method of the adsorbent for the separation of ethylene and ethane is the same as that in Example 3, except that sodium silicate is added as a binder and sodium cellulose as an auxiliary agent. The metal-modified molecular sieve is mixed with sodium silicate and sodium cellulose in a weight ratio of 1:0.10:0.01 to form a mixed powder. The preparation method parameters of the adsorbent are shown in Table 1.

[0168] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 3. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0169] Example 13

[0170] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 3.

[0171] (2) The preparation method of the adsorbent for the separation of ethylene and ethane is the same as that in Example 3, except that sodium silicate is added as a binder, and the metal-modified molecular sieve is mixed with sodium silicate and guar gum powder in a weight ratio of 1:0.08:0.02 to form a mixed powder. The preparation method parameters of the adsorbent are shown in Table 1.

[0172] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 3. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0173] Example 14

[0174] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1.

[0175] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0176] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1, except that: under conditions of 10°C and 0.5 MPa, the ethylene and ethane mixture, in which ethylene has a volume fraction of 50%, is subjected to a 1.0 h⁻¹ pressure. -1 The mass hourly space velocity (MHSV) of the gas is used to contact the activated adsorbent bed for selective adsorption. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0177] Example 15

[0178] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1.

[0179] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0180] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1, except that: under conditions of 20°C and 0.6 MPa, the ethylene and ethane mixture, in which ethylene has a volume fraction of 50%, is subjected to a 0.5-hour... -1 The mass hourly space velocity (MHSV) of the gas is used to contact the activated adsorbent bed for selective adsorption. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0181] Example 16

[0182] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1.

[0183] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0184] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1, except that: under conditions of 40°C and 1.0 MPa, the ethylene and ethane mixture, in which ethylene has a volume fraction of 50%, is subjected to a 3.0 h⁻¹ pressure. -1 The mass hourly space velocity (MHSV) of the gas is used to contact the activated adsorbent bed for selective adsorption. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0185] Example 17

[0186] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1.

[0187] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0188] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1, except that the adsorbent obtained in (2) above for the separation of ethylene and ethane is activated at 150°C under a nitrogen atmosphere for 180 min. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0189] Example 18

[0190] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1.

[0191] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0192] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1, except that the adsorbent obtained in (2) above for the separation of ethylene and ethane is activated at 300°C under an argon atmosphere for 150 min. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0193] Example 19

[0194] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1.

[0195] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0196] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1, except that the adsorbent obtained in (2) above for the separation of ethylene and ethane is activated at 450°C in a helium atmosphere for 30 min. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0197] Example 20

[0198] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1.

[0199] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0200] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1, except that the temperature of the adsorbent bed is raised to 80°C and the pressure is reduced to 0.001 MPa, so that the gas adsorbed on the adsorbent is desorbed from it. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0201] Example 21

[0202] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1.

[0203] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0204] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1, except that the temperature of the adsorbent bed is raised to 100°C and the pressure is reduced to 0.01 MPa, so that the gas adsorbed on the adsorbent is desorbed from it. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0205] Example 22

[0206] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1.

[0207] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0208] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1, except that the temperature of the adsorbent bed is raised to 200°C and the pressure is reduced to 0.1 MPa, so that the gas adsorbed on the adsorbent is desorbed from it. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0209] Example 23

[0210] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1.

[0211] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0212] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1, except that the temperature of the adsorbent bed is raised to 120°C and the pressure is reduced to 0.05 MPa, so that the gas adsorbed on the adsorbent is desorbed from it. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0213] Example 24

[0214] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 1.

[0215] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 1. The preparation method parameters of the adsorbent are shown in Table 1.

[0216] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 1, except that the temperature of the adsorbent bed is raised to 180°C and the pressure is reduced to 0.08 MPa, so that the gas adsorbed on the adsorbent is desorbed from it. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0217] Comparative Example 1

[0218] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 3, except that: both steps S1) and S2) are carried out at room temperature (25°C) for ion exchange.

[0219] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 3. The preparation method parameters of the adsorbent are shown in Table 1.

[0220] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 3. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0221] Comparative Example 2

[0222] (1) The preparation method of the metal-modified molecular sieve is the same as that in Example 3, except that: both steps S1) and S2) are carried out by ion exchange at an apparent pressure of 0.55 MPa (room temperature, 25 °C).

[0223] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 3. The preparation method parameters of the adsorbent are shown in Table 1.

[0224] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 3. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0225] Comparative Example 3

[0226] (1) The preparation method of metal-modified molecular sieve is the same as that in Example 3, except that: both steps S1) and S2) are carried out by ion exchange at a reaction temperature of 90℃ (without external pressure).

[0227] (2) The preparation method of the adsorbent used for the separation of ethylene and ethane is the same as that in Example 3. The preparation method parameters of the adsorbent are shown in Table 1.

[0228] (3) The method for concentrating ethylene from the ethylene and ethane mixture is the same as in Example 3. The volume fraction of ethylene in the desorbed gas is shown in Table 2.

[0229] Table 1. Preparation parameters of the adsorbents for the separation of ethylene and ethane in Examples 1-24 and Comparative Examples 1-3.

[0230]

[0231] Table 2. Method parameters for ethylene concentration using adsorbents in Examples 1-24 and Comparative Examples 1-3, and the volume fraction of ethylene in the desorbed gas.

[0232]

[0233] As can be seen from the data in Tables 1 and 2, the adsorbent of this application contains a specific metal-modified molecular sieve, which is obtained by ion exchange with the active metal ion component M1 and component M2 under the synergistic effect of specific apparent pressure and temperature. Furthermore, the specific ratio of components M1, M2, and sodium ions enables the adsorbent to effectively separate ethylene from a mixture of ethylene and ethane, resulting in a high concentration of ethylene gas. Specifically, compared to adsorbents obtained by ion exchange at room temperature (Comparative Example 1), under specific apparent pressure (Comparative Example 2), or under specific temperature (Comparative Example 3) (all other aspects are the same as the method of this application), the method of this application (Example 3), using a specific molecular sieve obtained under the combined effect of specific apparent pressure and temperature, with components M1, M2, and sodium ions satisfying a specific ratio, significantly improves the adsorption and separation performance of the obtained adsorbent, increasing the volume fraction of ethylene in the desorbed gas by 39.9%, 31.6%, and 15.7%, respectively.

[0234] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A sorbent for ethylene and ethane separation, characterized in that, The adsorbent comprises a metal-modified molecular sieve, a binder and an auxiliary agent, The metal-modified molecular sieve comprises a type A molecular sieve and a metal ion active component, the metal ion active component comprises component M1 and component M2, and the metal-modified molecular sieve satisfies the following formula (1): K is 0.92 to 1.0, preferably 0.95-1.0, The molar number of the metal ion active component M1, the molar number of the metal ion active component M2 and the molar number of sodium ions in the type A molecular sieve are obtained by X-ray fluorescence spectroscopy. x M1 is the valence of the metal ion active component M1, n M1 M1 is the number of moles of the metal ion active component, x M2 is the valence of the metal ion active component M2, n M2 M2 is the number of moles of the metal ion active component, n Na the number of moles of sodium ions in the A-type molecular sieve, The binder is sodium metaaluminate, sodium silicate or a combination thereof.

2. The adsorbent according to claim 1, characterized in that The metal ion active component M1 is at least one selected from the group consisting of Mg 2+ , Ca 2+ and Sr 2+ ; the component M2 is at least one selected from the group consisting of Ag + , Cu 2+ , Zn 2+ , Mn 2+ , Ni 2+ , Co 2+ , Cd 2+ , Fe 2+ , Fe 3+ and Cr 3+ , preferably at least one selected from the group consisting of Ag + , Zn 2+ , Mn 2+ , Fe 2+ and Co 2+ .

3. The adsorbent of claim 1, wherein, In the metal-modified molecular sieve, x M1 n M1 ·x M2 n M2 / (x M1 n M1 +x M2 n M2 ) is 0.172 to 0.245, preferably 0.200 to 0.

215.

4. The adsorbent according to any one of claims 1 to 3, characterized in that, The auxiliary agent is selected from at least one of sesbania powder, lignin and sodium cellulose.

5. The adsorbent according to any one of claims 1 to 3, characterized in that, The weight ratio of the metal-modified molecular sieve, the binder and the auxiliary agent is 1:(0.02-0.10):(0.01-0.03), preferably 1:(0.04-0.06):(0.02-0.03).

6. The adsorbent according to any one of claims 1 to 3, characterized in that, The preparation method comprises the following steps: mixing the metal-modified molecular sieve with the binder and the auxiliary agent, and then performing ball forming, drying and calcination to obtain a spherical adsorbent, wherein the metal-modified molecular sieve is obtained by the following steps:

7. A process for the preparation of the adsorbent for ethylene and ethane separation according to any one of claims 1 to 3, characterized in that, S1) performing ion exchange on the type A molecular sieve raw powder with a solution of a salt containing the metal ion active component M1 at an apparent pressure of 0.2-1.0 MPa and a temperature of 50-95℃; S2) performing ion exchange on the product obtained in step S1) with a solution of a salt containing the metal ion active component M2 at an apparent pressure of 0.2-1.0 MPa and a temperature of 50-95℃. The apparent pressure is 0.3-0.9 MPa, preferably 0.4-0.8 MPa, more preferably 0.5-0.7 MPa, and most preferably 0.55-0.65 MPa; and the temperature is 60-90℃, preferably 80-90℃.

8. The method of claim 7, wherein, The weight ratio of the type A molecular sieve raw powder, the salt containing the metal ion active component M1 and the salt containing the metal ion active component M2 is 1:(0.8-1.5):(0.2-0.6), preferably 1:(1-1.5):(0.2-0.45).

9. The method of claim 7, wherein, The salt comprising the metal ion active component M1 is a chloride, nitrate, sulfate or acetate salt comprising the metal ion active component M1 and the metal ion active component M1 is at least one selected from the group consisting of Mg 2+ , Ca 2+ and Sr 2+ ; the salt comprising the metal ion active component M2 is a chloride, nitrate, sulfate or acetate salt comprising the metal ion active component M2 and the metal ion active component M2 is at least one selected from the group consisting of Ag + , Cu 2 + , Zn 2+ , Mn 2+ , Ni 2+ , Co 2+ , Cd 2+ , Fe 2+ , Fe 3+ and Cr 3+ , preferably at least one selected from the group consisting of Ag + , Zn 2+ , Mn 2+ , Fe 2+ and Co 2+ .

10. The method of claim 7, wherein, The apparent pressure of 0.2-1 MPa is obtained by hydrothermal pressurization or air pressurization, preferably by air pressurization.

11. The method according to claim 7 or 8, characterized in that, The apparent pressure is 0.55-0.65 MPa and is obtained by air pressurization, and the temperature is 80-90℃.

12. The method of claim 7 or 8, wherein, The binder is sodium metaaluminate, sodium silicate or a combination thereof.

13. The method of claim 7, wherein, The auxiliary agent is selected from at least one of sesbania powder, lignin and sodium cellulose.

14. The method of claim 7, wherein, The weight ratio of the metal-modified molecular sieve, the binder and the auxiliary agent is 1:(0.02-0.10):(0.01-0.03), preferably 1:(0.04-0.06):(0.02-0.03).

15. The method of claim 7, wherein, 16. An adsorbent for separating ethylene and ethane, which is obtained by the preparation method according to any one of claims 7-15. The method comprises the following steps:

17. A method of concentrating ethylene, characterized by, 1) activating the adsorbent according to any one of claims 1-6, 16 to obtain an activated adsorbent; ​ 2) contacting a mixed gas of ethylene and ethane with a bed of activated adsorbent to perform selective adsorption, the adsorption temperature being 10-40°C, preferably 20-30°C, and the adsorption pressure being 0.5-1.0 MPa, preferably 0.6-0.8 MPa; 3) desorbing the gas adsorbed on the adsorbent, the desorption temperature being 80-200°C, and the desorption pressure being 0.001-0.1 MPa, preferably 0.005-0.08 MPa.

18. The ethylene enrichment process of claim 17 wherein, In the step 1), the activation is performed at a temperature of 150-450°C, preferably 200-400°C, for a time of 30-180 min, preferably 60-150 min, and in an atmosphere of nitrogen, argon or helium.

19. The ethylene enrichment process of claim 17 wherein, In the step 2), the mixed gas of ethylene and ethane has a mass space velocity of 0.3-3 h -1 , preferably 1.0-2.0 h -1 .

20. The ethylene enrichment process of claim 17 wherein, In the step 2), the contacting of the mixed gas of ethylene and ethane with a bed of activated adsorbent is performed by fixed bed adsorption or simulated moving bed adsorption.

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