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CN-116889805-B - For CO2High-efficiency separated zeolite membrane and preparation method and application thereof

CN116889805BCN 116889805 BCN116889805 BCN 116889805BCN-116889805-B

Abstract

The invention discloses a zeolite membrane for efficiently separating CO 2 , a preparation method and application thereof. The zeolite molecular sieve membrane is prepared by encapsulating organic guest molecules (or ions) in pore channels of the zeolite molecular sieve membrane, and then further regulating and controlling the structure and content of the organic guest molecules. Due to the strong interaction between the residual organic guest molecules and CO 2 , the diffusion rate of CO 2 in the zeolite molecular sieve membrane is greatly reduced, and finally, the efficient separation between CO 2 and other gas mixtures can be realized. Compared with the conventional zeolite molecular sieve membrane, the zeolite molecular sieve membrane can be used for separating CO 2 in various different mixture systems, has wide application field and greatly improves the adaptability.

Inventors

  • LI GANG
  • HU CUI
  • FAN SHUANSHI
  • LANG XUEMEI
  • WANG YANHONG

Assignees

  • 华南理工大学

Dates

Publication Date
20260508
Application Date
20230717

Claims (7)

  1. 1. A method for preparing a zeolite membrane for efficient separation of CO 2 , comprising the steps of: (1) Introducing organic guest molecules or ions into pore channels of the zeolite molecular sieve membrane, wherein the organic guest molecules or ions are substances with strong interaction with CO 2 molecules; (2) The structure and content of organic guest molecules or ions in the zeolite molecular sieve membrane pore canal are secondarily regulated and controlled, and the secondary regulation and control method is low-temperature heating slow decomposition or ultraviolet radiation decomposition.
  2. 2. The method according to claim 1, wherein in the step (1), the zeolite molecular sieve membrane is one or more of MFI, CHA, LTA, DDR, FAU, MOR, BEA types, and the substance having strong interaction with CO 2 molecules is one or more of organic amine and quaternary ammonium base.
  3. 3. The method according to claim 1, wherein in the step (1), the organic guest molecules or ions are introduced into the channels of the zeolite molecular sieve membrane by adding the organic guest molecules or ions into the zeolite molecular sieve membrane synthesis solution and then performing hydrothermal crystallization to directly encapsulate the organic guest molecules or ions into the zeolite molecular sieve membrane.
  4. 4. The preparation method of the ultraviolet radiation catalyst according to claim 1, wherein the low-temperature heating slow decomposition temperature is 200-350 ℃, the decomposition time is 20-200h, the low-temperature heating slow decomposition atmosphere is one of air, oxygen, hydrogen and ozone, the ultraviolet radiation decomposition time is 20-500h, and the decomposition temperature is less than 100 ℃.
  5. 5. A zeolite membrane produced by the production process of any one of claims 1 to 4.
  6. 6. The zeolite membrane of claim 5 for use in separation of CO 2 from a gas mixture, wherein the CO 2 gas separation test temperature is no greater than 350 ℃.
  7. 7. The zeolite membrane of claim 6 for use in the separation of CO 2 from a gas mixture, wherein the CO 2 gas separation test temperature is no greater than 200 ℃.

Description

Zeolite membrane for efficient separation of CO 2 and preparation method and application thereof Technical Field The invention belongs to the technical field of membrane separation, and particularly relates to a zeolite membrane for efficient separation of CO 2, and a preparation method and application thereof. Background Zeolite molecular sieves have uniform pore channels on a molecular level, excellent chemical stability and thermal stability, are considered as an ideal membrane separation material, and are widely applied to high-efficiency separation of various mixture systems at present. The zeolite molecular sieve membrane with small holes (such as SAPO-34, SSZ-13, DDR and the like) is widely studied to separate CO 2, particularly, the zeolite molecular sieve membrane has excellent separation performance in the separation process of a CO 2/CH4 mixture system, the permeability of CO 2 can reach 10- -7-10-6mol Pa-1m-2s-1 orders of magnitude, and the separation selectivity of CO 2/CH4 can reach more than 100. This is mainly due to the fact that on the one hand the CH 4 molecules are significantly larger than CO 2, resulting in significantly slower diffusion rates in the membrane than CO 2, and on the other hand the preferential adsorption of CO 2 by zeolite membranes also plays a crucial role in its excellent separation properties. The small-pore zeolite molecular sieve membrane has good application prospect in the natural gas industry. For a CO 2/CH4 mixture system with higher CO 2 concentration, for example, the concentration of CO 2 in some landfill gas can reach more than 60%, and the treatment capacity is large when separating CO 2, so that a large membrane area is required for the zeolite molecular sieve membrane through which the traditional CO 2 preferentially permeates, and the actual production cost is higher. In addition, for the separation of H 2 in small molecular mixture systems such as H 2/CO2, for example, hydrogen production products from methane steam reforming, the molecular sizes of H 2 and CO 2 are significantly smaller than the pore size of the zeolite molecular sieve membrane, so that the separation selectivity of the zeolite molecular sieve membrane to H 2/CO2 is generally low, and therefore, the separation system is not suitable for the separation of the system. In order to further improve the applicability of the zeolite molecular sieve membrane in the separation of the CO 2 -containing mixed gas, the development of a novel zeolite molecular sieve CO 2 separation membrane has important significance. Changing the interaction between the membrane material and CO 2 can greatly affect the permeation characteristics of CO 2. Boffa et al (ChemSusChem, 2008,1,437-443) prepared metallic Nb-doped silica films whose permeability was still much lower than that of N 2 et al, despite the relatively small molecular size of CO 2 compared to N 2 et al. This is mainly due to the strong interactions between the membrane and the CO 2 molecules, resulting in CO 2 having an extremely low diffusion rate. Disclosure of Invention In order to overcome the defects in the prior art, the invention aims to introduce specific guest molecules (or ions) into pore channels of the zeolite molecular sieve, so as to improve the interaction between the membrane and CO 2 molecules, thereby selectively and greatly reducing the diffusion rate of CO 2 in the membrane and finally obtaining the novel zeolite molecular sieve membrane for efficiently separating CO 2. In order to achieve the above object, the technical scheme of the present invention is as follows. A method for preparing a zeolite membrane for efficient separation of CO 2, comprising the steps of: (1) Introducing organic guest molecules or ions into pore channels of the zeolite molecular sieve membrane, wherein the organic guest molecules or ions are substances with strong interaction with CO 2 molecules; (2) The structure and content of organic guest molecules or ions in the zeolite molecular sieve membrane pore canal are secondarily regulated and controlled, and the secondary regulation and control method is low-temperature heating slow decomposition or ultraviolet radiation decomposition. Preferably, in step (1), the zeolite molecular sieve membrane is one or more of MFI, CHA, LTA, DDR, FAU, MOR, BEA types. Preferably, the substance having a strong interaction with the CO 2 molecule is one or more of an organic amine and a quaternary ammonium base. Preferably, the organic amine is one or more of monomethylamine, dimethylamine, trimethylamine, monoethylamine, monopropylamine, dipropylamine, tripropylamine, diethylamine, triethylamine, isopropylamine, diisopropylamine, cyclopropylamine, n-butylamine, di-n-butylamine, isobutylamine, sec-butylamine, ethylenediamine, 1, 2-propylenediamine, 1, 4-butylenediamine. Preferably, the structural general formula of the quaternary ammonium base is 3RN +OH-, wherein R is alkyl. Preferably, R is methyl, ethyl, propyl or b