A n-butene adsorbent and its preparation method and application

Abstract

The present invention relates to an n-butene adsorbent, its preparation method, and application. The carrier is a metal-organic framework material, and the active component comprises a Group IIA metal salt and titanium ions. The adsorbent allows n-butene to quickly enter the adsorbent pores and strongly interact with the adsorbent at a certain temperature, while allowing isobutene to flow out directly without interacting with the adsorbent. The preparation process is simple, the raw materials are readily available, and the production cost is low. The adsorbent can be used to measure changes in isobutene content in a temperature-programmed surface reaction of n-butene isomerization, and furthermore, to study and improve catalyst performance.

Description

Technical Field

[0001] The present invention relates to the technical field of gas adsorption determination of samples, and more particularly to an n-butene adsorbent, a preparation method thereof, and an application thereof. Background Art

[0002] C4 olefins include 1,3-butadiene (C4H6), 1-butene (n-C4H8), and isobutylene (iso-C4H8), all of which are fundamental organic raw materials for a variety of synthetic rubbers and chemicals. High-purity C4 olefins are highly valuable for downstream industries. Among the comprehensive utilization of C4 olefins is the skeletal isomerization of n-butene, which converts linear n-butenes into isobutylenes, thereby increasing the added value of linear C4 olefins and addressing the relative shortage of isobutylene resources. This reaction is a heterogeneous catalytic process. Temperature-programmed techniques can be used to measure the changes in the content of the reactant n-butene and the product isobutylene during the reaction, thereby studying the activity, selectivity, and reaction mechanism of the catalyst, playing a crucial role in the development and improvement of catalysts.

[0003] Gas chromatography is a commonly used instrument for detecting changes in gas content. n-Butene and isobutene are separated by a chromatographic column, and qualitative and quantitative analysis is performed based on their retention times. However, this method cannot detect changes in n-Butene and isobutene content in real time under programmed temperature conditions. Another commonly used detector is a mass spectrometer. However, because n-Butene and isobutene have similar molecular ion and fragmentation peaks, mass spectrometry cannot clearly distinguish the mass numbers (m / z) of n-Butene and isobutene.

[0004] Before the content change of reactant n-butene and product isobutene is detected by mass spectrometry, a kind of adsorbent can be added. At a certain temperature, the adsorbent can adsorb n-butene, and isobutene is not acted on. The change in isobutene content in the temperature-programmed surface reaction of n-butene isomerization can be measured. Since the properties of n-butene and isobutene are very close, the separation of n-butene and isobutene is a difficult problem. At present, the report of the separation of n-butene and isobutene in the prior art is to utilize zeolite, metal-organic framework material (MOFs) or porous coordination polymer (PCPs) etc. as adsorbent. The idea is to utilize the difference of porous material molecular size, shape, polarity, polarizability, coordination ability etc. to separate gas molecules. The most commonly used adsorbent is 5A molecular sieve. Patent CN102329180A "A method for preparing isobutene by adsorption separation method" discloses the 5A molecular sieve using calcium modification, by at least 3 fixed-bed adsorbers, separating and preparing n-butene and isobutene. Moreover, the existing technology mainly adjusts the adsorption and separation of n-butene and isobutene by changing the conditions in the separation process, which is difficult to use in the measurement technology of programmed temperature surface reaction.

[0005] Therefore, developing a new adsorbent and applying it in the determination technology of programmed temperature surface reaction can better study the changes in the content of reactants and products in the isomerization reaction of n-butene. Summary of the Invention

[0006] In response to the shortcomings of the prior art, one objective of the present invention is to provide an adsorbent for n-butene. This adsorbent allows n-butene to rapidly enter the adsorbent pores and interact strongly with the adsorbent at a specific temperature, while allowing isobutene to flow out directly without interacting with the adsorbent. This adsorbent is simple to prepare, uses readily available raw materials, and has low production costs. It can be used to measure changes in isobutene content during temperature-programmed surface reactions for n-butene isomerization, and can therefore be used to study and improve catalyst performance.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A n-butene adsorbent comprises a carrier and an active component; the carrier is a metal-organic framework (MOF) material, and the active component comprises a Group IIA metal salt and titanium ions. In the adsorbent, the active metal and organic ligands of the MOF material form a pore structure, with the Group IIA metal salt and titanium ions dispersed within the pores. MOF materials possess properties such as large specific surface area, ease of synthesis, and adjustable pore size and geometry. These characteristics meet the requirements of adsorbents for adsorption separation and have broad application prospects in the field of gas separation.

[0009] In the above technical solution, the central metal ion of the metal organic framework material is at least one of copper, zinc, iron and chromium ions, preferably zinc ion; the organic ligand of the metal organic framework material is at least one of terephthalic acid and trimesic acid, preferably terephthalic acid.

[0010] In the above technical solution, the Group IIA metal salt is selected from magnesium salts and / or calcium salts, preferably MgCl2.

[0011] In the above technical solution, the titanium ions are derived from a titanium precursor solution, preferably at least one of tetrabutyl titanate and titanium tetrachloride.

[0012] In the above technical solution, based on the total weight of the adsorbent, the content of the metal organic framework material is 50-70 wt%, the content of the Group IIA metal salt is 10-30 wt%, and the content of the titanium ion is 10-20 wt%.

[0013] In the above technical solution, based on the total weight of the adsorbent, the content of the metal organic framework material is 55-65wt%, the content of the Group IIA metal salt is 15-25wt%, and the content of the titanium ion is 10-15wt%. Within the above range, an adsorbent with better performance is obtained.

[0014] The second object of the present invention is to provide a method for preparing the n-butene adsorbent, which has a simple preparation process, readily available raw materials and low production cost.

[0015] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0016] The metal salt of the central metal ion of the metal organic framework material and the organic ligand are dissolved in a solvent, a Group IIA metal salt solution and a titanium precursor solution are added, and the resulting mixed solution reacts to obtain the adsorbent.

[0017] In a preferred embodiment of the above technical solution, the metal salt of the central metal ion of the metal organic framework material and the organic ligand are ultrasonically dissolved in a solvent; preferably,

[0018] Said Group IIA metal salt solution and titanium precursor solution are added to the mixed solution of the metal salt of the central metal ion of the metal organic framework material and the organic ligand respectively, preferably said Group IIA metal salt solution is added first; preferably,

[0019] The titanium precursor solution is added dropwise under stirring; preferably,

[0020] After the reaction, a solid is obtained, and the solid is washed and dried to obtain the adsorbent.

[0021] In a preferred embodiment of the above technical solution, the solvent for dissolving the metal salt of the central metal ion of the metal organic framework material and the organic ligand is selected from at least one of anhydrous ethanol, acetone and N,N-dimethylformamide, preferably anhydrous ethanol and / or N,N-dimethylformamide; preferably,

[0022] The solvent of the Group IIA metal salt solution is selected from at least one of anhydrous methanol, anhydrous ethanol, and anhydrous propanol, preferably anhydrous ethanol.

[0023] Preferably,

[0024] The solvent of the titanium precursor solution is selected from at least one of anhydrous methanol, anhydrous ethanol, and anhydrous propanol, preferably anhydrous ethanol; preferably,

[0025] The cleaning solvent is selected from at least one of anhydrous ethanol, acetone and N,N-dimethylformamide, preferably anhydrous ethanol and / or N,N-dimethylformamide.

[0026] In a preferred embodiment of the above technical solution, the solvent is added until the metal salt of the central metal ion of the metal organic framework material is fully dissolved in the solution, and its concentration is preferably 0.5 to 10% wt, more preferably 1 to 7% wt; preferably,

[0027] The solvent is added until the organic ligand is fully dissolved in the solution, and its concentration is preferably 0.5 to 10% wt, more preferably 1 to 7% wt; preferably,

[0028] The solvent is added until the Group IIA metal salt is fully dissolved in the solution, and its concentration is preferably 0.1 to 5% wt, more preferably 1 to 4% wt; preferably,

[0029] The solvent is added until the titanium ions are fully dissolved in the titanium precursor solution, and its concentration is preferably 1 to 20% wt, more preferably 2 to 15% wt.

[0030] In the above technical solution, the reaction temperature is 100-150°C, the reaction time is 0.5h-4h, the drying is preferably vacuum drying, the drying temperature is 80-120°C, and the drying time is 0.5-4h; further preferably, the reaction temperature is 120-140°C, the reaction time is 1-2h; the vacuum drying temperature is 100-120°C, and the time is 1-2h.

[0031] Preferably,

[0032] In the above technical solution, the preparation comprises the following steps: a) ultrasonically dissolving equimolar amounts of Zn(NO₃)₂·6H₂O and terephthalic acid (BDC) in N,N-dimethylformamide (DMF), referred to as mixture A; b) dissolving magnesium chloride in ethanol and heating it to form a solution, referred to as solution B; c) adding solution B to mixture A and stirring thoroughly, referred to as solution C; d) slowly adding tetrabutyl titanate dropwise to anhydrous ethanol and vigorously stirring, referred to as solution D; e) while stirring solution C, slowly adding solution D dropwise to solution C, referred to as solution E; f) transferring solution E to a sealed reactor and reacting at 100-150°C for 0.5-4 hours to obtain solid F; g) repeatedly washing solid F with pure DMF and vacuum drying at 100°C for 1 hour to obtain the finished adsorbent.

[0033] A third object of the present invention is to provide an application of an n-butene adsorbent in measuring the change in the isobutene content of the product in the n-butene isomerization surface reaction during a programmed temperature rise process.

[0034] A specific embodiment of the application of the present invention includes placing an adsorbent between a catalyst sample and a mass spectrometer detector, controlling the temperature of the adsorbent at 30-70°C, and measuring the change curve of the isobutylene content in a series of temperature-programmed surface reactions for n-butene isomerization by mass spectrometry.

[0035] The specific application steps may include: 1. Filling the activated adsorbent into a stainless steel sample tube, connecting both ends of the sample tube to a programmed temperature system via threaded ferrules, and positioning the tube between the mass spectrometer and the catalyst sample tube; 2. Equipping the stainless steel sample tube with a temperature control system with a temperature range of -40 to 150°C and a heating / cooling rate of 10 to 90°C / min.

[0036] The beneficial effects of the present invention are as follows: the adsorbent can allow n-butene to quickly enter the adsorbent pores and strongly interact with the adsorbent at a certain temperature, while allowing isobutene to flow out directly without interacting with the adsorbent. The present invention can be used to measure the change in isobutene content in the temperature-programmed surface reaction of n-butene isomerization, and further used for the research and improvement of catalyst performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 : A graph showing the change in the signal of isobutylene (m / z=56) detected by mass spectrometry on the adsorbent prepared in Example 1 over time. DETAILED DESCRIPTION

[0038] The present invention will be described in detail below with reference to specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and are not to be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art to the present invention based on the contents of the present invention still fall within the scope of protection of the present invention.

[0039] Reagent sources: All reagents are commercially available.

[0040] Test method:

[0041] 1. Test of adsorbent performance 1:

[0042] An adsorbent was added to the microreactor sample tube, and then 5% n-butene-95% argon (volume fraction) and 5% isobutylene-95% argon (volume fraction) were introduced into the sample tube at a flow rate of 30 mL / min. The sample tube temperatures were set to 0°C, 30°C, 50°C, 70°C, and 100°C, respectively. After stabilization for 1 minute, the n-butene and isobutylene contents were detected by gas chromatography.

[0043] 2. Test 2 of adsorbent performance:

[0044] An adsorbent was added to the microreactor sample tube, and then 5% n-butene-5% isobutene-90% argon (volume fraction) was introduced into the sample tube at a flow rate of 30 mL / min. The sample tube temperatures were set to 0°C, 30°C, 50°C, 70°C, and 100°C, respectively. After stabilization for 1 minute, the n-butene and isobutene contents were detected by gas chromatography.

[0045] 3. Temperature-programmed surface reaction:

[0046] Accurately weigh a certain mass of catalyst sample and place it in a sample tube. Place the sample tube in the instrument and introduce He gas. Under He purge, raise the temperature at 10°C / min to a certain temperature. Hold for a specified period of time, then cool to a certain temperature. Connect the adsorbent sample tube, positioned between the mass spectrometer and the catalyst sample tube, and set the adsorbent sample tube temperature. Then, introduce n-butene gas. Once the baseline stabilizes, raise the temperature at 10°C / min to a certain temperature. The mass spectrometer monitors the change in the isobutylene (m / z = 56) signal over time.

[0047] 4. Determination of the content of each component of the obtained adsorbent:

[0048] The sample is placed in a tablet press and pressed into a tablet. The pressed sample is placed in an X-ray diffractometer. Using Cu Kα rays, the tube voltage and tube current are set, and the contents of the central metal element of the metal organic framework material, the IIA main group metal element and the titanium element are respectively determined. Then, the contents of the metal organic framework material, the IIA main group metal salt and the titanium ion are calculated according to the chemical formula.

[0049] Example 1

[0050] The preparation method comprises the following steps:

[0051] a. Dissolve 0.71 g of Zn(NO3)2·6H2O and 0.40 g of BDC in 10 mL of DMF by ultrasonication and mix thoroughly. This mixture is referred to as mixture A.

[0052] b. Dissolve 0.15 g of magnesium chloride in 5 ml of ethanol and heat to form a solution, which is referred to as solution B.

[0053] c. Add solution B to mixture A and stir thoroughly, which is called solution C.

[0054] d. Slowly add 0.5 ml of tetrabutyl titanate dropwise to 5 ml of anhydrous ethanol and stir vigorously to mix well. This is referred to as solution D.

[0055] e. Solution C is kept in a stirring state, and solution D is slowly added dropwise to solution C, which is recorded as solution E;

[0056] f. Transfer solution E to a reactor, seal it, and react at 140°C for 1 hour to obtain solid F;

[0057] g. The solid F was repeatedly washed with pure DMF and dried under vacuum at 100° C. for 1 h to obtain the finished adsorbent 1.

[0058] The content of each component of the adsorbent is shown in Table 1, and the adsorption capacity of n-butene and isobutene is shown in Table 2. It can be seen that the adsorbent can almost completely adsorb n-butene and isobutene at 0°C, almost no adsorption of n-butene and isobutene occurs at 100°C, and n-butene can be adsorbed without adsorbing isobutene at 30-70°C.

[0059] Example 2

[0060] The preparation method comprises the following steps:

[0061] a. Dissolve 0.53 g of Cu(NO3)2·3H2O and 0.31 g of trimesic acid in 20 mL of a mixed solvent of water, DMF, and ethanol (wherein the volume ratio of water, DMF, and ethanol is 1:1:1) by ultrasonication, and mix thoroughly. This mixture is referred to as mixture A.

[0062] b. Dissolve 0.15 g of calcium chloride in 5 ml of ethanol and heat to form a solution, which is referred to as solution B.

[0063] c. Add solution B to mixture A and stir thoroughly, which is called solution C.

[0064] d. Slowly add 0.5 ml of tetrabutyl titanate dropwise to 5 ml of anhydrous ethanol and stir vigorously to mix well. This is referred to as solution D.

[0065] e. Solution C is kept in a stirring state, and solution D is slowly added dropwise to solution C, which is recorded as solution E;

[0066] f. Transfer solution E to a reactor, seal it, and react at 140°C for 1 hour to obtain solid F;

[0067] g. The solid F was repeatedly washed with pure DMF and dried under vacuum at 100° C. for 1 h to obtain the finished adsorbent 2.

[0068] The content of each component of the adsorbent is shown in Table 1, and the adsorption capacity of n-butene and isobutene is shown in Table 2. It can be seen that the adsorbent can almost completely adsorb n-butene and isobutene at 0°C, almost no adsorption of n-butene and isobutene occurs at 100°C, and n-butene can be adsorbed without adsorbing isobutene at 30-70°C.

[0069] Example 3

[0070] The difference from Example 1 is only the content of each component. The preparation method includes the following steps.

[0071] a. Dissolve 0.83 g of Zn(NO3)2·6H2O and 0.46 g of BDC in 10 mL of DMF by ultrasonication and mix thoroughly. This mixture is referred to as mixture A.

[0072] b. Dissolve 0.08 g of magnesium chloride in 5 ml of ethanol and heat to form a solution, which is referred to as solution B.

[0073] c. Add solution B to mixture A and stir thoroughly, which is called solution C.

[0074] d. Slowly add 0.35 ml of tetrabutyl titanate dropwise to 5 ml of anhydrous ethanol and stir vigorously to mix well. This is referred to as solution D.

[0075] e. Solution C is kept in a stirring state, and solution D is slowly added dropwise to solution C, which is recorded as solution E;

[0076] f. Transfer solution E to a reactor, seal it, and react at 140°C for 1 hour to obtain solid F;

[0077] g. The solid F was repeatedly washed with pure DMF and dried under vacuum at 100° C. for 1 h to obtain the finished adsorbent 3.

[0078] The content of each component of the adsorbent is shown in Table 1, and the adsorption capacity of n-butene and isobutene is shown in Table 2. It can be seen that the adsorbent can almost completely adsorb n-butene and isobutene at 0°C, almost no adsorption of n-butene and isobutene occurs at 100°C, and n-butene can be adsorbed without adsorbing isobutene at 30-70°C.

[0079] Example 4

[0080] The adsorbent was prepared in the same manner as in Example 1, with the following differences from Example 1: f) reacting at 120° C. for 2 h to obtain adsorbent 4.

[0081] The content of each component of the adsorbent is shown in Table 1, and the adsorption capacity of n-butene and isobutene is shown in Table 2. It can be seen that the adsorbent can almost completely adsorb n-butene and isobutene at 0°C, almost no adsorption of n-butene and isobutene occurs at 100°C, and n-butene can be adsorbed without adsorbing isobutene at 30-70°C.

[0082] Example 5

[0083] The adsorbent was prepared in the same manner as in Example 1, with the following differences from Example 1: g) vacuum drying at 110° C. for 1.5 h to obtain adsorbent 5.

[0084] The content of each component of the adsorbent is shown in Table 1, and the adsorption capacity of n-butene and isobutene is shown in Table 2. It can be seen that the adsorbent can almost completely adsorb n-butene and isobutene at 0°C, almost no adsorption of n-butene and isobutene occurs at 100°C, and n-butene can be adsorbed without adsorbing isobutene at 30-70°C.

[0085] Example 6

[0086] The only difference from Example 1 is that no magnesium salt is added. The preparation method comprises the following steps:

[0087] a. Dissolve 0.71 g of Zn(NO3)2·6H2O and 0.40 g of BDC in 10 mL of DMF by ultrasonication and mix thoroughly. This mixture is referred to as mixture A.

[0088] b. Slowly add 0.5 ml of tetrabutyl titanate dropwise to 5 ml of anhydrous ethanol and stir vigorously until evenly mixed. This is referred to as solution B.

[0089] c. Mixture A is kept in a stirring state, and solution B is slowly added dropwise to mixture A, which is recorded as solution C;

[0090] d. Transfer solution C to a reactor, seal it, and react at 140°C for 1 hour to obtain solid D;

[0091] e. The solid D was repeatedly washed with pure DMF and dried under vacuum at 100° C. for 1 h to obtain the finished adsorbent 6.

[0092] The content of each component of the adsorbent is shown in Table 1, and the adsorption capacity of n-butene and isobutene is shown in Table 2. It can be seen that the adsorbent can almost completely adsorb n-butene and isobutene at 0°C, and almost no adsorption of n-butene and isobutene occurs at 100°C. At 30-70°C, it can adsorb n-butene and also some isobutene.

[0093] Example 7

[0094] The difference from Example 1 is that the magnesium salt is changed to calcium salt. The preparation method comprises the following steps:

[0095] a. Dissolve 0.71 g of Zn(NO3)2·6H2O and 0.40 g of BDC in 10 mL of DMF by ultrasonication and mix thoroughly. This mixture is referred to as mixture A.

[0096] b. Dissolve 0.15 g of calcium chloride in 5 ml of ethanol and heat to form a solution, which is referred to as solution B.

[0097] c. Add solution B to mixture A and stir thoroughly, which is called solution C.

[0098] d. Slowly add 0.5 ml of tetrabutyl titanate dropwise to 5 ml of anhydrous ethanol and stir vigorously to mix well. This is referred to as solution D.

[0099] e. Solution C is kept in a stirring state, and solution D is slowly added dropwise to solution C, which is recorded as solution E;

[0100] f. Transfer solution E to a reactor, seal it, and react at 140°C for 1 hour to obtain solid F;

[0101] g. The solid F was repeatedly washed with pure DMF and dried under vacuum at 100° C. for 1 h to obtain the finished adsorbent 7.

[0102] The content of each component of the adsorbent is shown in Table 1, and the adsorption capacity of n-butene and isobutene is shown in Table 2. It can be seen that the adsorbent can almost completely adsorb n-butene and isobutene at 0°C, almost no adsorption of n-butene and isobutene occurs at 100°C, and n-butene can be adsorbed without adsorbing isobutene at 30-70°C.

[0103] Example 8

[0104] The adsorbent used is the finished adsorbent prepared according to Example 1. The application method comprises the following steps:

[0105] 1. Accurately weigh 0.1g of catalyst A and 0.1g of catalyst B into sample tubes, and then place the sample tubes into the instrument.

[0106] 2. Place a certain amount of adsorbent in the adsorbent sample tube, located between the mass spectrometer and the catalyst sample tube.

[0107] 3. Introduce He gas and raise the temperature to 500°C at 10°C / min under He purge. After maintaining for a certain period of time, cool down to room temperature. Connect the adsorbent sample tube, which is located between the mass spectrometer and the catalyst sample tube. The temperature of the adsorbent sample tube is 50°C. Then, introduce n-butene gas. After the baseline is stable, raise the temperature to 500°C at 10°C / min. Use the mass spectrometer to detect the change of the isobutylene (m / z=56) signal over time, as shown in Figure 3. Figure 1 shown.

[0108] It was observed that for catalyst A, n-butene isomerized to isobutene at approximately 300°C, peaked at 400°C, and then decreased in isobutene content. For catalyst B, n-butene isomerized to isobutene at approximately 320°C, peaked at 430°C, and then decreased in isobutene content. This method can be used to determine the change in isobutene content during the temperature-programmed surface reaction of n-butene isomerization.

[0109] Comparative Example 1

[0110] The adsorbent was prepared in the same manner as in Example 1, except that the adsorbent did not contain titanium ions.

[0111] The content of each component of the adsorbent is shown in Table 1, and the adsorption capacity of n-butene and isobutene is shown in Table 2. It can be seen that the adsorbent can almost completely adsorb n-butene and isobutene at 0°C, almost no adsorption of n-butene and isobutene occurs at 100°C, and the adsorption amount of n-butene and isobutene is similar at 30-70°C.

[0112] Comparative Example 2

[0113] The adsorbent was prepared in the same manner as in Example 1, except that the adsorbent did not contain titanium ions and Group IIA metal salts.

[0114] The content of each component of the adsorbent is shown in Table 1, and the adsorption capacity of n-butene and isobutene is shown in Table 2. It can be seen that the adsorbent can almost completely adsorb n-butene and isobutene at 0°C, almost no adsorption of n-butene and isobutene occurs at 100°C, and the adsorption amount of n-butene and isobutene is similar at 30-70°C.

[0115] Comparative Example 3

[0116] The commonly used ZSM-5 molecular sieve was used as the adsorbent, and the adsorption capacity of n-butene and isobutene is shown in Table 2.

[0117] It can be seen that at 30-70°C, the adsorption amounts of n-butene and isobutene are similar.

[0118] Comparative Example 4

[0119] The commonly used SAPO-11 molecular sieve was used as the adsorbent, and the adsorption capacity of n-butene and isobutene is shown in Table 2. It can be seen that the adsorption amount of n-butene and isobutene is similar at 30-70°C.

[0120] Test Example 1

[0121] The content of each component in the adsorbents obtained in the above examples and comparative examples was determined by X-ray fluorescence spectroscopy.

[0122] The results are shown in Table 1.

[0123] Table 1 Adsorbent characteristic test results

[0124]

[0125]

[0126] Test Example 2

[0127] The adsorption capacity of the adsorbents obtained in the above examples and comparative examples for n-butene and isobutene was measured according to Test Method 1 (Test 1 of Adsorbent Performance).

[0128] The results are shown in Table 2.

[0129] Table 2 Adsorbent adsorption test results

[0130]

[0131]

[0132] Test Example 3

[0133] The adsorption capacity of the adsorbent obtained in Example 1 for n-butene and isobutene was measured according to Test Method 2 (Test 2 of Adsorbent Performance).

[0134] The results are shown in Table 3.

[0135] Table 3 Adsorbent adsorption test results

[0136]

[0137] It should be noted that the above embodiments are only used to illustrate the present invention and do not constitute any limitation to the present invention.

Claims

1. A n-butene adsorbent comprising a carrier and an active component; wherein: The carrier is a metal-organic framework material, the active component contains a Group IIA metal salt and a titanium ion; the central metal ion of the metal-organic framework material is at least one of copper, zinc, iron and chromium ions; the organic ligand of the metal-organic framework material is at least one of terephthalic acid, diphenyl dicarboxylic acid and trimesic acid.

2. The adsorbent according to claim 1, characterized in that The central metal ion of the metal organic framework material is zinc ion; the organic ligand of the metal organic framework material is terephthalic acid.

3. The adsorbent according to claim 1, characterized in that The Group IIA metal salt is selected from magnesium salts and / or calcium salts.

4. The adsorbent according to claim 3, characterized in that The Group IIA metal salt is MgCl2.

5. The adsorbent according to claim 1, characterized in that The titanium ions are derived from a titanium precursor solution.

6. The adsorbent according to claim 5, characterized in that The titanium ions are derived from at least one of tetrabutyl titanate and titanium tetrachloride.

7. The adsorbent according to claim 1, characterized in that Based on the total weight of the adsorbent, the content of the metal organic framework material is 50-70 wt %, the content of the Group IIA metal salt is 10-30 wt %, and the content of the titanium ion is 10-20 wt %.

8. The adsorbent according to claim 7, characterized in that Based on the total weight of the adsorbent, the content of the metal organic framework material is 55-65 wt %, the content of the Group IIA metal salt is 15-25 wt %, and the content of the titanium ion is 10-15 wt %.

9. A method for preparing the adsorbent according to any one of claims 1 to 8, comprising: The metal salt of the central metal ion of the metal organic framework material and the organic ligand are dissolved in a solvent, a Group IIA metal salt solution and a titanium precursor solution are added, and the resulting mixed solution reacts to obtain the adsorbent.

10. The method according to claim 9, characterized in that dissolving the metal salt of the central metal ion of the metal organic framework material and the organic ligand in a solvent by ultrasonic wave; and / or, adding the Group IIA metal salt solution and the titanium precursor solution to the mixed solution of the metal salt of the central metal ion of the metal organic framework material and the organic ligand respectively; and / or, The titanium precursor solution is added dropwise under stirring; and / or, After the reaction, a solid is obtained, and the solid is washed and dried to obtain the adsorbent.

11. The method according to claim 10, characterized in that The Group IIA metal salt solution is first added into a mixed solution of the metal salt of the central metal ion of the metal organic framework material and the organic ligand.

12. The method according to claim 11, characterized in that The solvent for dissolving the metal salt of the central metal ion of the metal organic framework material and the organic ligand is selected from at least one of anhydrous ethanol, acetone and N,N-dimethylformamide; and / or, The solvent of the Group IIA metal salt solution is selected from at least one of anhydrous methanol, anhydrous ethanol, and anhydrous propanol; The solvent of the titanium precursor solution is selected from at least one of anhydrous methanol, anhydrous ethanol, and anhydrous propanol; and / or, The solid cleaning solvent is selected from at least one of anhydrous ethanol, acetone and N,N-dimethylformamide.

13. The method according to claim 12, characterized in that The solvent for dissolving the metal salt of the central metal ion of the metal organic framework material and the organic ligand is anhydrous ethanol and / or N,N-dimethylformamide; and / or, The solvent of the Group IIA metal salt solution is anhydrous ethanol, The solvent of the titanium precursor solution is anhydrous ethanol; and / or, The solid cleaning solvent is anhydrous ethanol and / or N,N-dimethylformamide.

14. The method according to claim 12, characterized in that The concentration of the metal salt of the central metal ion of the metal organic framework material in the solution is 0.5-10% wt; and / or, The concentration of the organic ligand in the solution is 0.5-10% wt; and / or, The concentration of the Group IIA metal salt solution is 0.1-5% wt; and / or, The concentration of the titanium ions in the titanium precursor solution is 1-20%wt.

15. The method according to claim 14, characterized in that The concentration of the metal salt of the central metal ion of the metal organic framework material in the solution is 1-7% wt; and / or, The concentration of the organic ligand in the solution is 1-7% wt; and / or, The concentration of the Group IIA metal salt solution is 1-4% wt; and / or, The concentration of the titanium ions in the titanium precursor solution is 2-15%wt.

16. The method according to claim 9, characterized in that The reaction temperature is 100-150° C., and the reaction time is 0.5 h-4 h.

17. The method according to claim 16, characterized in that The reaction temperature is 120-140° C., and the reaction time is 1-2 hours.

18. The method according to claim 10, wherein: The drying temperature is 80-120° C., and the drying time is 0.5-4 hours.

19. The method according to claim 18, characterized in that The drying is vacuum drying, and the vacuum drying temperature is 100-120° C. and the time is 1-2 hours.

20. The method according to any one of claims 9 to 19, characterized in that The molar ratio of the metal salt of the central metal ion of the metal organic framework material to the organic ligand is 2 to 0.5; and / or, Based on 100 parts by weight of the metal salt of the central metal ion of the metal organic framework material, the amount of the Group IIA metal salt is 10 to 60 parts; and / or, Based on 100 parts by weight of the metal salt of the central metal ion of the metal organic framework material, the amount of the titanium precursor is 10 to 100 parts.

21. The method according to claim 20, characterized in that The molar ratio of the metal salt of the central metal ion of the metal organic framework material to the organic ligand is 1.5 to 0.66; and / or, Based on 100 parts by weight of the metal salt of the central metal ion of the metal organic framework material, the amount of the Group IIA metal salt is 15 to 50 parts; and / or, Based on 100 parts by weight of the metal salt of the central metal ion of the metal organic framework material, the amount of the titanium precursor is 20 to 80 parts.

22. Use of the adsorbent according to any one of claims 1 to 8 or the adsorbent prepared by the preparation method according to any one of claims 9 to 19 in measuring the change in isobutylene content in a surface reaction of n-butene isomerization during a temperature programmed heating process; The adsorbent can adsorb normal butene but not isobutene at a temperature of 30-70°C.

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