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EP-4497499-B1 - METHOD FOR PREPARING AN AMINE-FUNCTIONALIZED ADSORBENT

EP4497499B1EP 4497499 B1EP4497499 B1EP 4497499B1EP-4497499-B1

Inventors

  • YAN, FENG
  • ZHANG, Zuotai
  • SUN, XIN
  • XU, JIYUN

Dates

Publication Date
20260513
Application Date
20240528

Claims (8)

  1. A method for preparing an amine-functionalized adsorbent, wherein the amine-functionalized adsorbent comprises a metal-organic framework, MOF, material and polymeric amine, a crystal structure of the MOF material is a three-dimensional cage-like pore structure, and the polymeric amine is loaded inside the three-dimensional cage-like pore structure, the method comprising: preparing the MOF material by: dissolving a soluble metal salt, an organic ligand and a mineralizing agent into a first solvent to form a solution, reacting at a temperature between 100 °C-240 °C for a duration of for 6 h-48 h, and filtering the solution after the reaction is finished to obtain the MOF material, wherein a molar ratio of the soluble metal salt to the organic ligand is 1: (0.125-4), and metal ions in the soluble metal salt comprise one or both of Cr 3+ and Zn 2+ ; adding the MOF material and the polymeric amine into a second solvent; reacting through physical impregnation at a temperature between 30 °C-90 °C for a duration of 2 h-12 h; and drying to obtain the amine-functionalized adsorbent, wherein: the MOF material and the polymeric amine are mixed under the impact of an ultrasonic wave after added to the second solvent, wherein a duration of application of the ultrasonic wave is 10 min-60 min, a frequency of the ultrasonic wave is 10 KHz-60 KHz, and power of the ultrasonic wave is 50 W-500 W, and the polymeric amine is polyethylene imine.
  2. The method for preparing the amine-functionalized adsorbent according to claim 1, wherein: an interior of the three-dimensional cage-like pore structure contains an acidic site formed by an unsaturated metal site; a pore size of the three-dimensional cage-like pore structure is 1.5 nm-3.4 nm; and the polymeric amine binds with the MOF material through the acidic site.
  3. The method for preparing the amine-functionalized adsorbent according to claim 1, wherein: a specific surface area of the MOF material is 2000 m 2 /g-3500 m 2 /g; and a pore volume of the MOF material is 1.0 cm 3 /g-1.5 cm 3 /g.
  4. The method for preparing the amine-functionalized adsorbent according to claim 1, wherein: the organic ligand is selected from a group consisting of terephthalic acid, dimethylimidazole and derivatives thereof; the mineralizing agent is selected from a group consisting of hydrofluoric acid and sodium acetate; the first solvent is selected from a group consisting of deionized water, anhydrous methanol, and anhydrous ethanol.
  5. The method for preparing the amine-functionalized adsorbent according to claim 1, wherein a mass ratio of the MOF material to the polymeric amine is 1: (0.33-15).
  6. The method for preparing the amine-functionalized adsorbent according to claim 1, wherein the second solvent is a water-soluble component which is selected from a group consisting of a deionized aqueous solution, anhydrous methanol, and anhydrous ethanol.
  7. The method for preparing the amine-functionalized adsorbent according to claim 1, the method further comprising: before the MOF material is mixed with the polymeric amine, placing the MOF material in an oxygen-free environment at 100 °C-150 °C for activation, wherein the oxygen-free environment is achieved by vacuumizing, charging N 2 or discharging air with an inert gas.
  8. The method for preparing the amine-functionalized adsorbent according to claim 1, wherein conditions of the drying are as follows: drying for 3 h-4 h at 30 °C-80 °C, or ventilating for 1 h-4 h before drying and then drying for 3 h-4 h at 30 °C-80 °C.

Description

FIELD OF TECHNOLOGY The present invention relates to the field of adsorbents, and particularly to an amine-functionalized adsorbent and a method for preparing the same. BACKGROUND Carbon capture is a means to reduce the concentration of carbon dioxide in an atmosphere through direct fixation of carbon dioxide. Solid amine materials are often used for carbon capture due to their advantages of large adsorption capacity, low energy consumption and strong interaction with carbon dioxide. At present, the capture of carbon dioxide using the amine-functionalized adsorbent is generally achieved by thermal adsorption. At room temperature, the amine-functionalized adsorbent has low adsorption capacity and slow adsorption speed of carbon dioxide, and therefore it is urgent to further improve. CN113101904 discloses a method for preparing a composite material of PEI and MOF-74 comprising the steps of Preparation of Zn-MOF-74: Dissolving zinc nitrate hexahydrate and 2,5-dihydroxyterephthalic acid in N,N-dimethylformamide, and obtaining Zn-MOF-74 material under hydrothermal reaction conditions; Dissolving polyethyleneimine in different proportions in methanol, drying the Zn-MOF-74 material to remove adsorbed water and coordinated water, dropping the polyethyleneimine methanol solution into the Zn-MOF-74 material under ultrasonic treatment, then compounding the obtained sample under nitrogen protection, and drying to obtain the target product. CN104056598 discloses a MOF-based adsorbent for CO2 which comprises a MOF and an organic amine in a mass ratio of MOF to organic amine of 0.1 to 10:1. The MOFs may be MOFs, ZIFs, MILs. The polyamine may be PEI. The MOF-based carbon dioxide adsorbent provided by the present invention achieves the combined action of physical adsorption and chemical adsorption, adsorbs and stores carbon dioxide at medium and low temperatures, and realizes the regeneration and reuse of the adsorbent under certain conditions. The MOF-based carbon dioxide adsorbent has good adsorption capacity, high selectivity and cyclic stability for carbon dioxide, can overcome the shortcomings of organic amines such as easy volatility and equipment corrosion, and meets the requirements of industrial treatment. The invention also discloses a preparation method of the MOF-based carbon dioxide adsorbent and its application in carbon dioxide adsorption from flue gas. SUMMARY In order to achieve the above objective, the present invention discloses an amine-functionalized adsorbent and a method for preparing the same. The amine-functionalized adsorbent has the advantages of high adsorption capacity and rapid adsorption speed of carbon dioxide without additional heat input. Aspects of the invention are set out in the independent claims. Compared with the prior art, the present disclosure has the beneficial effects below: The present disclosure provides an amine-functionalized adsorbent. By using the MOF material with the three-dimensional cage-like pore structure as a support of polymeric amine, the three-dimensional cage-like pore structure of this pore size provides a channel for entry of the polymeric amine, thereby loading the polymeric amine onto the interior of the three-dimensional cage-like pore structure of the MOF material so that adjacent amine-functionalized adsorbents are not prone to aggregation. The amine-functionalized adsorbent can rapidly adsorb lots of carbon dioxide, the adsorption capacity of carbon dioxide at a normal temperature is greatly increased and adsorption equilibrium is rapidly reached, the adsorption capacity and adsorption rate of carbon dioxide at the normal temperature are significantly increased, so as to address the problem that at the normal temperature, the adsorption capacity of carbon dioxide is extremely low and the adsorption rate of carbon dioxide is low. BRIEF DESCRIPTION OF THE DRAWINGS In order to explain the technical solutions of the embodiments of the present disclosure more clearly, the following will briefly introduce the accompanying drawings used in the embodiments. Apparently, the drawings in the following description are only some embodiments of the present disclosure. Those of ordinary skill in the art can obtain other drawings based on these drawings without creative work. FIG. 1 is a Fourier transform infrared spectroscopy (FT-IR) of MOF material and an amine-functionalized adsorbent disclosed in Example 1 of the present invention.FIG. 2 is a scanning electron microscope (SEM) image of an amine-functionalized adsorbent disclosed in Example 1 of the present invention.FIG. 3 is a transmission electron microscope (TEM) image of MOF material disclosed in Example 1 of the present invention before and after loading polymeric amine.FIG. 4 is a curve graph showing pore size distribution of an MOF material disclosed in Example 1 of the present invention.FIG. 5 is a Brunner-Emmet-Teller (BET) adsorption curve graph of an amine-functionalized adsorbent disclosed in Example 1 of