A method for preparing a phosphonic acid-based polymeric-scolecite foam co2 adsorbent and applications thereof

Abstract

The application discloses a preparation method of a phosphoric acid-based geopolymer-stellerite foam CO2 adsorbent and application thereof. The preparation comprises the following steps: mixing stellerite powder and metakaolin to obtain solid-phase raw materials, then adding the solid-phase raw materials into an acid activator, uniformly stirring, adding a foaming agent and a foam stabilizer to foam, and finally pouring and forming, curing to obtain the phosphoric acid-based geopolymer-stellerite foam material; wherein the mass ratio of the stellerite powder and the metakaolin is 1:10-6:4; the acid activator is a 4-12 mol / L phosphoric acid solution; and the mass ratio of the solid-phase raw materials and the acid activator is 1:(0.6-1). The preparation method uses cheap and easily available natural stellerite and metakaolin as raw materials, has low cost and simple process, and the obtained foam CO2 adsorbent can effectively adsorb CO2, has good structural stability, excellent water resistance, and has a wide application prospect.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of composite materials, and particularly relates to a preparation method of a phosphoric acid-based geopolymer-clinoptilolite foam CO2 adsorbent and application thereof. BACKGROUND

[0002] Clinoptilolite has multiple excellent properties such as ion exchange, adsorption and catalysis, and its theoretical chemical formula is (Na, K, Ca) 2-3 [Al3(Al, Si)2Si 13 O 16 ]·12H2O, which is a natural molecular sieve. This porous mineral is widely used for adsorbing organic matter, heavy metals and gases (such as CO2), and is an ideal adsorbent with good quality and low price. Clinoptilolite is also often used as a catalyst in the fields of oil refining and chemical industry. Clinoptilolite can also be used for water quality improvement, softening of hard water ions in water, and improvement of the quality of drinking water and industrial water. In addition, as a feed additive, it helps to adsorb and decompose toxins, and at the same time improves the nutrient absorption of feed. However, the current clinoptilolite adsorption material is mainly in the form of powder or granules, and special support is required in the packed bed adsorption process. The powder product is not easy to recover, and may cause secondary pollution.

[0003] In patent CN115090276A, a method for in-situ loading of X-type zeolite porous geopolymer is disclosed, in which the X-type zeolite is in-situ loaded on the pore wall of the porous geopolymer by saturated steam curing to obtain an in-situ loaded X-type zeolite porous geopolymer for capturing carbon dioxide in flue gas. In patent CN114272910A, a fly ash-based porous geopolymer-zeolite composite material is prepared by loading zeolite on the fly ash-based porous geopolymer material by steam curing. The fly ash-based porous geopolymer-zeolite composite material prepared by the method has high heavy metal adsorption capacity. However, these patents require related equipment such as saturated steam preparation and curing of the material, which has high requirements and high energy consumption, and is difficult to implement on a large scale. In addition, the activator used in the preparation of the geopolymer is a strong alkaline NaOH and Na2SiO3 solution, and the product is an alkaline material. When this material is used in an environment with high CO2 content, the alkali reacts with carbon dioxide to form carbonate, and CO2 promotes the weathering of the product, affecting the long-term structural stability and recycling performance of the material. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a preparation method of a phosphoric acid-based geopolymer-clinoptilolite foam CO2 adsorbent and application thereof. The obtained foam CO2 adsorbent can effectively adsorb CO2, has good structural stability and excellent water resistance, the preparation method is simple, and has a wide application prospect.

[0005] To solve the above technical problems, the present application adopts the following technical solutions:

[0006] A preparation method of a phosphoric acid-based geopolymer-heulandite foam CO2 adsorbent is provided, comprising the following steps:

[0007] The heulandite powder is mixed with the metakaolin to obtain a solid-phase raw material, and then the solid-phase raw material is added to an acid activator, and after being stirred uniformly, a foaming agent and a foam stabilizer are added for foaming, and finally, the phosphoric acid-based geopolymer-heulandite foam material is obtained after casting, curing, etc.

[0008] The mass ratio of the heulandite powder to the metakaolin is 1:10-6:4.

[0009] The acid activator is a 4-12 mol / L phosphoric acid solution.

[0010] The mass ratio of the solid-phase raw material to the acid activator is 1:(0.6-1).

[0011] According to the above scheme, the mass ratio of the heulandite powder to the metakaolin is 2:8-5:5, and the acid activator is a 5-10 mol / L phosphoric acid solution. Preferably, the mass ratio of the heulandite powder to the metakaolin is 3:7-5:5, and the acid activator is a 6-9 mol / L phosphoric acid solution. More preferably, the mass ratio of the heulandite powder to the metakaolin is 4:6-5:5, and the acid activator is a 7-8 mol / L phosphoric acid solution.

[0012] According to the above scheme, the heulandite powder is prepared by crushing and sieving the collected heulandite ore. Preferably, the sieving is performed through a 60-200 mesh sieve.

[0013] According to the above scheme, the foaming agent is hydrogen peroxide, aluminum powder, zinc powder or silicon powder, and the foam stabilizer is triton.

[0014] According to the above scheme, the addition amount of the foaming agent is 1-5% of the mass of the solid-phase raw material, and the addition amount of the foam stabilizer is 0.5-1% of the mass of the solid-phase raw material.

[0015] According to the above scheme, the curing condition is curing at 60-100°C for 24-48h.

[0016] According to the above scheme, the prepared phosphoric acid-based geopolymer-heulandite foam CO2 adsorbent has a compressive strength of 1-3 MPa and a bulk density in the range of 0.6-1.2 g / cm 3 .

[0017] According to the above scheme, the acid activator is prepared by diluting a phosphoric acid solution (85wt%) with deionized water, and then standing for 24-48h.

[0018] The application provides application of the phosphoric acid geopolymer-clinoptilolite foam CO2 adsorbent prepared by the method to adsorb CO2.

[0019] The application has the following beneficial effects:

[0020] 1. The application uses cheap and easily available natural clinoptilolite and metakaolin as raw materials, and a phosphoric acid solution as an activator to prepare a phosphoric acid geopolymer- clinoptilolite porous foam material by foaming; the porous foam effectively combines the mesopores in the geopolymer and the micropores of the clinoptilolite, the product has a good multi-level pore structure, can be used as a low-cost green environmental protection material for gas adsorption and sewage treatment, can effectively adsorb CO2, has good structural stability, excellent water resistance, and has a wide application prospect.

[0021] 2. The application obtains better CO2 adsorption performance and geopolymer performance by complementing between natural mineral raw materials; meanwhile, using a plurality of natural mineral materials as geopolymer precursor raw materials can reduce production costs and has important significance for energy saving and emission reduction and resource utilization.

[0022] 3. The application uses a phosphoric acid geopolymer as an inorganic gel and natural clinoptilolite as a filler to prepare a mineral-based monolithic material with certain mechanical strength and good CO2 adsorption performance, and solves the problems of the traditional powder adsorbent, such as difficult recycling, easy secondary pollution, and poor recycling performance. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 Figure (a) is a real photo of the phosphoric acid geopolymer-clinoptilolite foam environmental protection material prepared in different ratio conditions in the embodiments of the application, and figure (b) is a field emission scanning electron microscope photo thereof.

[0024] Figure 2 Figure is an XRD pattern of the phosphoric acid geopolymer-clinoptilolite foam material prepared in Example 3 of the application.

[0025] Figure 3 Figure is CO2 recycling performance of the phosphoric acid geopolymer-clinoptilolite foam material prepared in Example 3 of the application. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the application clearer, the application is further described in detail below with reference to the drawings and examples. It should be understood that the specific examples described herein are only used to explain the application, and are not used to limit the application.

[0027] The main chemical components and contents of the metakaolin and clinoptilolite used in the following examples are shown in Table 1.

[0028] Table 1 Main chemical composition and content of metakaolin and clinoptilolite

[0029]

[0030] Example 1

[0031] A method for preparing a phosphoric acid-based polymer-clinoptilolite foam CO2 adsorbent is provided, comprising the following steps:

[0032] Solid phase raw material preparation: The clinoptilolite ore is crushed by a jaw crusher, further ground by a grinding instrument, and then passed through a 60-mesh sieve to obtain clinoptilolite powder. The clinoptilolite and metakaolin are mixed in a mass ratio of 1:9 to prepare the raw material for the phosphoric acid-based geopolymer-clinoptilolite foam.

[0033] Preparation of an acidic activator: A phosphoric acid solution (85wt%) is diluted with deionized water to prepare an 8mol / L phosphoric acid solution, and then an acidic activator is obtained after standing for 24h.

[0034] Preparation of a foam material: The solid phase raw material and the acidic activator are mixed in a mass ratio of 1:0.84, i.e., 100 parts of the solid phase raw material and 84 parts of the acidic activator are stirred uniformly by a high-speed dispersion machine, then 4 parts of hydrogen peroxide foaming agent and 1 part of triton foam stabilizer are added, and the mixture is stirred uniformly and then cast into a mold. The foam is placed in an electric heating air drying oven and cured at 80°C for 36h to obtain a phosphoric acid-based geopolymer-clinoptilolite foam environmental protection material. The prepared material has a compressive strength of 3MPa and a bulk density of 0.72g / cm 3 , and has water resistance.

[0035] Example 2

[0036] A method for preparing a phosphoric acid-based polymer-clinoptilolite foam CO2 adsorbent is provided, comprising the following steps:

[0037] Solid phase raw material preparation: The clinoptilolite ore is crushed by a jaw crusher, further ground by a grinding instrument, and then passed through a 60-mesh sieve to obtain clinoptilolite powder. The clinoptilolite and metakaolin are mixed in a mass ratio of 1:9 to prepare the raw material for the phosphoric acid-based geopolymer-clinoptilolite foam.

[0038] Preparation of an acidic activator: A phosphoric acid solution (85wt%) is diluted with deionized water to prepare an 8mol / L phosphoric acid solution, and then an acidic activator is obtained after standing for 24h.

[0039] Preparation of the foam material: the solid raw material and the acid activator are mixed in a mass ratio of 1:0.84, that is, 100 parts of the solid raw material and 84 parts of the acid activator are stirred uniformly by a high-speed dispersion machine, then 4 parts of hydrogen peroxide foaming agent and 1 part of triton foam stabilizer are added, and after uniform stirring, the mixture is poured into a formwork and placed in an electric heating air drying oven for curing at 80°C for 36h to obtain the phosphoric acid-based polymer-heulandite foam environmentally friendly material. The compressive strength of the prepared material is 2.45MPa, and the bulk density is 0.83g / cm 3 , which has water resistance.

[0040] Example 3

[0041] A preparation method of a phosphoric acid-based polymer-heulandite foam CO2 adsorbent is provided, which comprises the following steps:

[0042] Preparation of the solid raw material: the heulandite ore is crushed by a jaw crusher, further ground by a grinder, and then sieved through a 60-mesh sieve to obtain heulandite powder. The heulandite and the metakaolin are mixed in a mass ratio of 5:5 to prepare the raw material for the phosphoric acid-based polymer-heulandite foam.

[0043] Preparation of the acid activator: a phosphoric acid solution (85wt%) is diluted with deionized water to prepare an 8mol / L phosphoric acid solution, and then an acid activator is obtained by standing for 24h.

[0044] Preparation of the foam material: the solid raw material and the acid activator are mixed in a mass ratio of 1:0.84, that is, 100 parts of the solid raw material and 84 parts of the acid activator are stirred uniformly by a high-speed dispersion machine, then 4 parts of hydrogen peroxide foaming agent and 1 part of triton foam stabilizer are added, and after uniform stirring, the mixture is poured into a formwork and placed in an electric heating air drying oven for curing at 80°C for 36h to obtain the phosphoric acid-based polymer-heulandite foam environmentally friendly material. The compressive strength of the prepared material is 2.45MPa, and the bulk density is 0.83g / cm 3 , which has water resistance.

[0045] Example 4

[0046] A preparation method of a phosphoric acid-based polymer-heulandite foam CO2 adsorbent is provided, which comprises the following steps:

[0047] Preparation of the solid raw material: the heulandite ore is crushed by a jaw crusher, further ground by a grinder, and then sieved through a 60-mesh sieve to obtain heulandite powder. The heulandite and the metakaolin are mixed in a mass ratio of 5:5 to prepare the raw material for the phosphoric acid-based polymer-heulandite foam.

[0048] Preparation of acid activator: dilute phosphoric acid solution (85wt%) with deionized water to prepare a 6mol / L phosphoric acid solution, and then stand for 24h to obtain the acid activator.

[0049] Preparation of foam material: mix the solid raw material with the acid activator at a mass ratio of 1:0.84, i.e. take 100 parts of the solid raw material and 84 parts of the acid activator, stir them uniformly with a high-speed dispersion machine, then add 4 parts of hydrogen peroxide foaming agent and 1 part of triton foam stabilizer, stir them uniformly, and then pour and shape them, and then put them into an electric heating air drying oven to cure at 80°C for 36h, to obtain the phosphoric acid-based geopolymer-heulandite foam environmental protection material, the compressive strength of which is 1.04MPa, and the bulk density is 0.91g / cm 3 , which has water resistance.

[0050] Example 5

[0051] A method for preparing a phosphoric acid-based geopolymer-heulandite foam CO2 adsorbent is provided, which comprises the following steps:

[0052] Preparation of solid raw material: crush the heulandite ore with a jaw crusher, further grind it with a grinder, and then pass it through a 60-mesh sieve to obtain heulandite powder. Mix the heulandite with the metakaolin at a mass ratio of 5:5 to prepare the raw material for the phosphoric acid-based geopolymer-heulandite foam.

[0053] Preparation of acid activator: dilute phosphoric acid solution (85wt%) with deionized water to prepare a 10mol / L phosphoric acid solution, and then stand for 24h to obtain the acid activator.

[0054] Preparation of foam material: mix the solid raw material with the acid activator at a mass ratio of 1:0.84, i.e. take 100 parts of the solid raw material and 84 parts of the acid activator, stir them uniformly with a high-speed dispersion machine, then add 4 parts of hydrogen peroxide foaming agent and 1 part of triton foam stabilizer, stir them uniformly, and then pour and shape them, and then put them into an electric heating air drying oven to cure at 80°C for 36h, to obtain the phosphoric acid-based geopolymer-heulandite foam environmental protection material, the compressive strength of which is 2.61MPa, and the bulk density is 1.19g / cm 3 , which has water resistance.

[0055] Comparative Example 1

[0056] A method for preparing a phosphoric acid-based geopolymer foam environmental protection material is provided, which comprises the following steps:

[0057] Preparation of solid raw material: crush the heulandite ore with a jaw crusher, further grind it with a grinder, and then pass it through a 60-mesh sieve to obtain heulandite powder. Mix the heulandite with the metakaolin at a mass ratio of 5:5 to prepare the raw material for the phosphoric acid-based geopolymer-heulandite foam.

[0058] Preparation of acid activator: dilute phosphoric acid solution (85wt%) with deionized water to prepare 8mol / L phosphoric acid solution, then stand for 24h to obtain acid activator.

[0059] Preparation of foam material: mix solid raw material with acid activator according to the mass ratio of 1:0.84, i.e. take 100 parts of solid raw material, 84 parts of acid activator, stir uniformly with high-speed dispersion machine, then add 4 parts of hydrogen peroxide foaming agent and 1 part of triton foam stabilizer, stir uniformly, then pour and shape, put into electric heating air drying oven, solidify at 80℃ for 36h, then obtain phosphoric acid-based geopolymer foam environmental protection material, the compressive strength of the prepared material is 1.23MPa, the bulk density is 0.6g / cm 3 , with water resistance.

[0060] Comparative example 2

[0061] A kind of phosphoric acid-based clinoptilolite foam environmental protection material is provided, comprising the following steps:

[0062] Preparation of solid raw material: crush clinoptilolite ore with jaw crusher, further grind with grinder and pass through 60 mesh sieve to obtain clinoptilolite powder. Mix clinoptilolite with metakaolin according to the mass ratio of 10:0, i.e. without adding metakaolin.

[0063] Preparation of acid activator: dilute phosphoric acid solution (85wt%) with deionized water to prepare 8mol / L phosphoric acid solution, then stand for 24h to obtain acid activator.

[0064] Preparation of foam material: mix solid raw material with acid activator according to the mass ratio of 1:0.84, i.e. take 100 parts of solid raw material, 84 parts of acid activator, stir uniformly with high-speed dispersion machine, then add 4 parts of hydrogen peroxide foaming agent and 1 part of triton foam stabilizer, stir uniformly, then pour and shape, put into electric heating air drying oven, solidify at 80℃ for 36h, then obtain phosphoric acid-based clinoptilolite foam environmental protection material, the compressive strength of the prepared material is 0.2MPa, the bulk density is 1.2g / cm 3 , which will gradually dissolve in water.

[0065] Figure 1 Photos of phosphoric acid-based geopolymer-clinoptilolite foam environmental protection materials prepared in examples 1-5 and comparative example 1 (a) and their field emission scanning electron microscope photos (b). Figure 1 It is shown that the phosphoric acid-based geopolymer-clinoptilolite foam material has unevenly distributed but interconnected pores (<1mm), and the material exhibits a porous structure similar to foam, which can improve the transmission rate of molecules and is beneficial to the application of molecular adsorption in industrial adsorption or adsorption packed bed.

[0066] Table 1 The phosphoric acid geopolymer-heulandite foams prepared in Examples 1-5 and Comparative Examples 1-2 were selected to conduct carbon dioxide gas adsorption and compressive strength, water resistance test, and the results of comprehensive evaluation of the prepared material of the present application are shown in Table 1. Table 1 shows that the compressive strength of the geopolymer prepared in Examples 1-5 and Comparative Example 1-2 is different, indicating that the concentration of the acid activator and the amount of zeolite added will affect the degree of geopolymerization. Specifically, with the increase of the concentration of phosphoric acid, more geopolymeric gel materials are formed; adding an appropriate amount of heulandite as a filler can reduce the generation of large pores and cracks in the material and enhance the compressive strength of the material, and the Si-O bond of the natural heulandite will not be destroyed after acid treatment and will not participate in the geopolymerization reaction, and with the increase of the substitution amount of zeolite, the geopolymer matrix in the material decreases, thereby reducing the compressive strength. However, with the increase of the amount of zeolite added, the adsorption amount of CO2 in the material increases, especially the phosphoric acid geopolymer-heulandite foam prepared in Example 3, which has the highest CO2 adsorption amount and the highest separation efficiency (calculated by the multi-component competitive adsorption breakthrough curve, that is, the ratio of CO2 / N2 saturated adsorption amount when the adsorption equilibrium is reached) for N2 / CO2 binary mixed gas (50 / 50 vol%), because the lepidocrocite type aluminum phosphate ( Figure 2 ) is generated, which increases the specific surface area of the material, and the presence of lepidocrocite type aluminum phosphate not only improves the adsorption performance of the material but also enhances the mechanical strength of the material. Alkali-activated geopolymer, because a large amount of unreacted alkaline solution remains in the pores, the alkaline solution will react with carbon dioxide and water to produce bicarbonate, carbonate and other products, and the geopolymer will be carbonized and decomposed, resulting in poor water resistance, while the phosphoric acid geopolymer prepared in Examples 1-5 and Comparative Example 1 does not have such problems. However, Comparative Example 1 only uses phosphoric acid geopolymer as the adsorbent, and the CO2 adsorption capacity is poor, and pure phosphoric acid geopolymer is not suitable as a CO2 adsorbent, only after being compounded with heulandite, the material has excellent CO2 adsorption performance and recycling performance. And only heulandite is used as an aluminum-silicon source, under the action of an acid activator, the Al-O bond in heulandite is destroyed and combines with P-O in the acid activator to form AlPO4, and the Si-O bond is not destroyed, further forming structural units with higher aggregation. Therefore, the geopolymer prepared in Comparative Example 2 has poor water resistance and will gradually be dissolved in water.

[0067] The phosphoric acid geopolymer-heulandite foam prepared in Example 3 was selected to test the CO2 recycling performance, and the adsorption process was carried out in a CO2 environment, and the desorption process was carried out in a N2 environment, and the experimental conditions were 25°C and 1 bar. The results are shown in Figure 3 ; Figure 3The results show that the CO2 adsorption capacity of the phosphoric acid-based geopolymer-heulandite foam material does not change obviously after 5 adsorption / desorption cycles, indicating that the material has good CO2 recycling performance.

[0068] Table 1 Comparison of basic properties of phosphoric acid-based geopolymer-heulandite foam environmentally friendly materials

[0069]

[0070] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and the technical scope disclosed by the present application is all covered within the protection scope of the present application.

Claims

1. A method of making a phosphosilicate-zeolite foam CO2 adsorbent, characterized by, The method comprises the following steps: The clinoptilolite powder is mixed with the metakaolin to obtain a solid-phase raw material, the solid-phase raw material is added into an acid activator, the foam is generated after the uniform stirring of the acid activator, a foaming agent and a foam stabilizer are added, and the foam is poured into a mold, solidified and cured to obtain the phosphoric acid-based geopolymer-clinoptilolite foam CO2 adsorbent. The mass ratio of the clinoptilolite powder to the metakaolin is 3:7-6:

4. The acid activator is an 8-12 mol / L phosphoric acid solution. The mass ratio of the solid-phase raw material to the acid activator is 1:0.6-1.

2. The production method according to claim 1, characterized by, The clinoptilolite powder is prepared by crushing and grinding the collected clinoptilolite ore and sieving.

3. The preparation method according to claim 1, characterized in that, The foaming agent is hydrogen peroxide, aluminum powder, zinc powder or silicon powder, and the foam stabilizer is triton.

4. The method of claim 1, wherein, The addition amount of the foaming agent is 1-5% of the mass of the solid-phase raw material, and the addition amount of the foam stabilizer is 0.5-1% of the mass of the solid-phase raw material.

5. The preparation method according to claim 1, characterized in that, The solidification condition is that the solidification is performed at 60-100 ℃ for 24-48 h.

6. The method of claim 1, wherein, The resulting phosphosilicate-stilbite foam CO2 adsorbent has a compressive strength between 1-3 MPa and a bulk density in the range 0.6-1.2 g / cm 3 .

7. The preparation method according to claim 1, characterized in that, The acid activator is prepared by diluting an 85 wt% phosphoric acid solution with deionized water and then standing for 24-48 h.

8. The use of the phosphoric acid-based geopolymer-clinoptilolite foam CO2 adsorbent prepared by the method of any one of claims 1-7 in adsorbing CO2.

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