Method for preparing solid amine gas adsorption material
The present invention relates to a method for preparing a solid amine gas adsorption material. The method synthesizes a porous solid amine gas adsorption material that loads organic amine evenly. In the method, a certain amount of acidic gas is introduced while organic amine molecules are introduced into a silicate solution as template agents, which not only makes sizes of SiO 2 pore channels homogeneous, but also makes organic amine molecules highly evenly distributed on a surface of SiO 2 . In addition, the acidic gas protects —NH 2 groups of organic amine, and avoids —NH 2 adhesion inactivation due to hydrogen bonding during the synthesis process of the material. The present invention also relates to a method for preparing a solid amine gas adsorption material after obtaining a silicate solution from fly ash. The solid amine gas adsorption material prepared has more stable and effective gas adsorption performance.
1. A method for preparing a solid amine gas adsorption material, comprising the steps of:
1) adding an organic amine to a silicate solution, introducing an acidic gas to the solution while stirring, until the pH value of the solution is 9 to 11, to obtain a SiO 2 sol or gel precipitate; and
2) filtering off the SiO 2 sol or gel precipitate from the above solution, and aging, drying, and dehydrating, to obtain a solid amine gas adsorption material.
2. The method according to claim 1 , wherein the silicate solution is a sodium silicate solution and/or a potassium silicate solution.
3. The method according to claim 1 , wherein the concentration of the silicate solution is 5 to 50 wt %.
4. The method according to claim 1 , wherein the silicate solution is prepared by filtering the reaction mixture obtained by subjecting fly ash and an alkali solution to alkali fusion.
5. The method according to claim 4 , wherein the source of the alkali in the alkali solution is selected from one or more of a group consisting of amino compounds, alkali hydrides, and alkali hydroxides.
6. The method according to claim 4 , wherein fly ash and a 10 to 30 wt % alkali solution are subjected to alkali fusion according to a solid-liquid weight ratio of 1:1 to 1:5.
7. The method according to claim 4 , wherein the alkali fusion reaction lasts for 30 to 120 min.
8. The method according to claim 4 , wherein the alkali fusion reaction is carried out at a temperature between 30 and 120° C.
9. The method according to claim 1 , wherein said acidic gas is selected from one or more of a group consisting of carbon oxides, sulphur oxides, nitrogen oxides, and sulphur hydrides.
10. The method according to claim 1 , wherein said organic amine is selected from the group consisting of polyethyleneimine (PEI), tetraethylenepentamine (TEPA), ethylenediamine, butanediamine, hexanediamine, tris(2-aminoethyl)amine, acrylonitrile, cyanuric chloride, diisopropylethylamine, methyl acrylate, and mixtures thereof.
11. The method according to claim 1 , wherein the ratio between the mass of the organic amine and the mass of the obtained solid amine gas adsorption material is from 1:10 to 6:10.
12. The method according to claim 1 , wherein the flow rate of said acidic gas is 5 to 15 L/min.
13. The method according to claim 1 , wherein aging, drying, and dehydrating are performed at a temperature between 100 and 120° C.