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CN-118179438-B - Organic amine modified HMS molecular sieve and application thereof in carbon dioxide capturing

CN118179438BCN 118179438 BCN118179438 BCN 118179438BCN-118179438-B

Abstract

The invention discloses an organic amine modified HMS molecular sieve and application thereof in carbon dioxide capture, wherein mesoporous molecular sieve HMS is prepared firstly, the mesoporous molecular sieve HMS comprises two pore structures, wherein the pore structures are respectively 4.5-8.0 nm and 11.5-17.5 nm, X-ray powder diffraction shows a single wide diffraction peak at 2 theta=2.6deg.C, then aminosilane is grafted on the surface of the mesoporous molecular sieve HMS, and finally the mesoporous molecular sieve HMS is immersed in an organic amine solution to obtain a multi-level organic amine modified HMS molecular sieve. The synthesis method is simple, the carbon dioxide adsorption efficiency is high, and the thermal stability is good.

Inventors

  • HU YUHAO
  • MENG ZEYOU
  • YE XIN
  • SUN XIAO
  • XIE GANG

Assignees

  • 西北大学

Dates

Publication Date
20260508
Application Date
20240313

Claims (8)

  1. 1. The preparation method of the organic amine modified HMS molecular sieve is characterized by comprising the following steps of: (1) Preparing a mesoporous molecular sieve HMS, wherein the HMS contains two pore structures, namely 4.5-8.0 nm and 11.5-17.5 nm, and an X-ray powder diffraction presents a single wide diffraction peak at2 theta = 2.6 degrees; (2) Grafting aminosilane on the surface of the mesoporous molecular sieve HMS prepared in the step (1); (3) Immersing the HMS molecular sieve grafted with the aminosilane in the step (2) in an organic amine solution.
  2. 2. The method for preparing an organic amine modified HMS molecular sieve according to claim 1, wherein the aminosilane is selected from the group consisting of (3-aminopropyl) trimethoxysilane, (3-aminopropyl) triethoxysilane, 3-aminopropyl methyldiethoxysilane, and N- (2-aminoethyl) -3-aminopropyl methyldiethoxysilane.
  3. 3. The method for preparing an organic amine modified HMS molecular sieve according to claim 1, wherein the organic amine is selected from the group consisting of tetraethylenepentamine, polyethyleneimine, palmitoylethanolamine, pentaethylenehexamine, and tris (2-aminoethyl) amine.
  4. 4. The method for preparing the organic amine modified HMS molecular sieve according to claim 1, wherein the method for synthesizing the mesoporous molecular sieve HMS is characterized in that a template agent polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer is added into 25-35 wt% hydrochloric acid solution, stirred until the mixture is clarified, heated to 35-60 ℃, tetraethyl silicate is added, fully stirred and subjected to hydrothermal reaction at 80-140 ℃, and the product is calcined at 500-600 ℃ to remove the template agent, so that the mesoporous molecular sieve HMS is obtained, and the molar ratio of the template agent to the tetraethyl silicate is 1:40-80.
  5. 5. The method for preparing the organic amine modified HMS molecular sieve according to claim 1, wherein in the step (2), before the aminosilane is grafted on the surface of the mesoporous molecular sieve HMS, the mesoporous molecular sieve HMS is subjected to activation treatment at 100-150 ℃.
  6. 6. The method for preparing an organic amine modified HMS molecular sieve according to claim 1, wherein in the step (2), mesoporous molecular sieve HMS is added into a polar organic solvent of aminosilane for reflux treatment under the protection of nitrogen.
  7. 7. The method for preparing an organic amine modified HMS molecular sieve according to claim 6, wherein the polar organic solvent is selected from toluene, ethanol, methanol, acetonitrile.
  8. 8. The method for preparing an organic amine-modified HMS molecular sieve according to claim 7, wherein the polar organic solvent is toluene.

Description

Organic amine modified HMS molecular sieve and application thereof in carbon dioxide capturing Technical Field The invention relates to an organic amine modified HMS molecular sieve and application thereof in carbon dioxide capturing, and belongs to the technical field of carbon dioxide capturing materials. Background Silica is one of the most abundant materials found in the world and is found in many different minerals in various environments. SiO 2 is usually present in the form of quartz in nature, which is the main component of sand, and quartz accounts for more than 10% of the crust. The synthesis of SiO 2 is very easy, the synthesized silicon dioxide generally has high specific surface area and porosity, and the structural characteristics of the silicon dioxide can be regulated by proper changes in the synthesis process. Mesoporous silica has the excellent choice of adsorbents due to its large pore volume, adjustable pore size, high surface area and structural characteristics that are easy to modify. Although silica has attractive structural characteristics, the adsorption efficiency of the unmodified silica trapping agent on CO 2 is not high, fortunately, a large amount of Si-OH exists on the surface of the silica, and a necessary condition is provided for introducing functional groups which are beneficial to trapping carbon dioxide into the silica. Because amines are basic in nature, loading of amino groups into the silica support facilitates providing high affinity active sites for CO 2, facilitating carbon dioxide capture. For amine-loaded silica adsorbents, it is desirable to select the appropriate precursor and modify the silica support itself to ensure good performance of the amino solid adsorbent. In terms of amine screening, song et al reported the incorporation of branched polyvinyl alcohol into MCM-41 by wet impregnation (Energy & Fuels, 2002, 16 (6), 1463-1469). They observed that the carbon dioxide adsorption capacity of the modified adsorbent increased from 8.6 mg g -1 of support MCM-41 to 112 mg g -1 under a pure carbon dioxide atmosphere at 75 ℃. The adsorption capacities (International Journal of Greenhouse Gas Control, 2016, 51, 230-238) of ethanolamine (MEA), diethanolamine (DEA) and Triethanolamine (TEA) impregnated MCM-41 were studied by Ahmed et al to better understand the effect of different amine types on adsorbent performance. Under the same conditions, the adsorption capacity is MEA (primary amine) > DEA (secondary amine) > TEA (tertiary amine) in this order. lai et al developed an amine (aminoethylethanolamine) impregnated silicic acid sorbent (APPLIED ENERGY, 2018, 223, 293-301) for capturing carbon dioxide in flue gas. The carbon dioxide saturation adsorption of the 55. 55 wt% AEEA impregnated aminosilic acid adsorbent was 4.54. 4.54 mmol g -1 at 25℃with 10% CO 2 and 10% H 2 O. Disclosure of Invention The invention aims to provide an organic amine modified HMS molecular sieve and application thereof in carbon dioxide capture, and the special pore structure is constructed to mainly solve the phenomena of pore channel blockage and agglomeration of too much modifier so as to improve the amine load capacity and further improve the carbon dioxide adsorption performance. The implementation process of the invention is as follows: A method for preparing a multi-layer organic amine modified HMS molecular sieve, which comprises the following steps: (1) Preparing a mesoporous molecular sieve HMS, wherein the HMS contains two pore structures, namely 4.5-8.0 nm and 11.5-17.5 nm, and an X-ray powder diffraction presents a single wide diffraction peak at 2θ=2.6o; (2) Grafting aminosilane on the HMS surface of the multi-level mesoporous molecular sieve prepared in the step (1); (3) Immersing the HMS molecular sieve grafted with the aminosilane in the step (2) in an organic amine solution. In the preparation method of the multi-layer organic amine modified HMS molecular sieve, the aminosilane is selected from (3-aminopropyl) trimethoxysilane, (3-aminopropyl) triethoxysilane, 3-aminopropyl methyl diethoxysilane, N- (2-aminoethyl) -3-aminopropyl methyl diethoxysilane and 3-aminopropyl methyl diethoxysilane. In the preparation method of the multi-layer organic amine modified HMS molecular sieve, the organic amine is selected from tetraethylenepentamine, polyethyleneimine, palmitoylethanolamine, pentaethylenehexamine and tri (2-aminoethyl) amine. The preparation method of the multi-layer organic amine modified HMS molecular sieve comprises the steps of (1) adding a template agent of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer into 25-35 wt% hydrochloric acid solution, stirring until the mixture is clear, heating the mixture to 35-60 ℃, adding tetraethyl silicate, fully stirring the mixture, performing hydrothermal reaction at 80-140 ℃, calcining the product at 500-600 ℃ to remove the template agent, and obtaining the mesoporous molecular sieve HMS, w