Y molecular sieve adsorbent, and preparation method and application thereof

Abstract

The application provides a Y molecular sieve adsorbent and a preparation method and application thereof. The preparation method comprises the following steps: mixing a pore-expanding agent and a Y molecular sieve, and calcining to obtain the Y molecular sieve adsorbent; wherein the pore-expanding agent comprises any one or a combination of at least two of sulfuric acid, hydrochloric acid, nitric acid, acetic acid, a sodium hydroxide solution, a potassium hydroxide solution, lactic acid, ammonia water, malic acid, succinic acid, propionic acid, formic acid, sodium carbonate, amino acid, ascorbic acid or sodium silicate. The application mixes the pore-expanding agent and the Y molecular sieve, and then performs calcination, so that the pore-expanding agent is effectively eliminated, the pore of the Y molecular sieve adsorbent is improved, the Y molecular sieve adsorbent with excellent adsorption performance is prepared, and efficient adsorption of carbon dioxide is realized. The preparation process of the Y molecular sieve adsorbent is simple, the preparation process cost is low, and the Y molecular sieve adsorbent has the advantages of green environmental protection.

Description

Technical Field

[0001] This invention belongs to the field of carbon dioxide adsorption materials, and relates to a Y molecular sieve adsorbent, its preparation method and application. Background Technology

[0002] Y-type molecular sieves are widely used in various industrial applications, including but not limited to gas adsorption, catalytic cracking, and pollutant removal, due to their unique pore structure and high surface area. However, traditional Y-type molecular sieves exhibit limitations in adsorption, such as limited CO2 adsorption capacity and insufficient selectivity.

[0003] In recent years, the modification of Y-type molecular sieves has attracted widespread attention from researchers. Modification methods mainly include ion exchange, metal doping, and amine modification, which can improve the CO2 adsorption performance of Y-type molecular sieves. Currently, the main method for modifying Y-type molecular sieves is to combine these modification techniques, which can effectively enhance their CO2 adsorption performance. Therefore, improving the CO2 adsorption performance of Y-type molecular sieves through modification processes is an important research direction. Although research in this area shows a positive trend, current modification methods are often complex, costly, and inconsistent in efficiency.

[0004] CN102335589A discloses an adsorbent, its preparation method, and its application. The method uses octahedral zeolite (X and Y types), LTA type, mordenite, or ZSM-5 molecular sieve as the adsorbent carrier. The carrier is placed in a solution of thiocyanate, potassium chloride, etc., for ion exchange, then washed and dried, and finally calcined in a muffle furnace to prepare the desired adsorbent. The adsorbent is then applied to remove sulfur dioxide, nitrogen oxides, and carbon dioxide from coal-fired flue gas, achieving the purpose of purifying the flue gas.

[0005] CN114713186A discloses a modified molecular sieve for CO2 adsorption and separation, as well as its preparation method and apparatus. This method employs vacuum gas-phase stepwise dynamic deposition, overcoming the shortcomings of traditional organic amine impregnation methods, such as uneven loading and easy pore blockage. It also produces no waste liquid and is easily mass-produced industrially. It exhibits high CO2 adsorption capacity under low pressure; at 25℃ and 0.1 bar, the highest measured CO2 adsorption capacity reached 3.35 mmol g. -1 Compared with the original sample, the low-pressure adsorption capacity increased by 50%.

[0006] Existing modification methods for Y-type molecular sieves have improved the adsorption capacity of Y-type zeolites for CO2 to some extent. However, challenges such as high cost, increased complexity, or reduced stability still exist.

[0007] Therefore, there is a need to develop an improved method for preparing Y molecular sieve adsorbents to overcome these limitations of existing technologies and to provide a cost-effective solution with higher adsorption efficiency. This is a pressing technical problem that needs to be solved. Summary of the Invention

[0008] The purpose of this invention is to provide a high-cost and high-adsorption-capacity Y molecular sieve adsorbent, its preparation method, and its application.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] One objective of this invention is to provide a method for preparing a Y molecular sieve adsorbent, the method comprising: mixing a pore-expanding agent and a Y molecular sieve, and then calcining the mixture to obtain the Y molecular sieve adsorbent;

[0011] The pore-expanding agent comprises any one or at least two combinations of sulfuric acid, hydrochloric acid, nitric acid, acetic acid, sodium hydroxide solution, potassium hydroxide solution, lactic acid, ammonia, malic acid, succinic acid, propionic acid, formic acid, sodium carbonate, amino acids, ascorbic acid, or sodium silicate. Typical but non-limiting examples of such combinations include: combinations of sulfuric acid and hydrochloric acid, combinations of hydrochloric acid and nitric acid, combinations of nitric acid and acetic acid, combinations of acetic acid and sodium hydroxide solution, combinations of sodium hydroxide solution and potassium hydroxide solution, combinations of potassium hydroxide solution and lactic acid, combinations of lactic acid and ammonia, combinations of ammonia and malic acid, combinations of malic acid and succinic acid, combinations of succinic acid and propionic acid, combinations of propionic acid and formic acid, combinations of formic acid and sodium carbonate, combinations of amino acids and ascorbic acid, combinations of sodium carbonate and ascorbic acid, or combinations of sodium silicate and lactic acid.

[0012] This invention involves mixing a pore-expanding agent with a Y-type molecular sieve, followed by calcination to eliminate the pore-expanding agent and improve the pore structure of the Y-type molecular sieve adsorbent. This results in a Y-type molecular sieve adsorbent with excellent adsorption performance, thereby achieving efficient adsorption of carbon dioxide. The preparation process of the Y-type molecular sieve adsorbent of this invention is simple, inexpensive, and environmentally friendly.

[0013] As a preferred technical solution of the present invention, the pore-expanding agent includes any one or a combination of at least two of sodium hydroxide, lactic acid, sodium carbonate or ascorbic acid, wherein typical but non-limiting examples of the combination include: a combination of sodium hydroxide and lactic acid, a combination of lactic acid and sodium carbonate, a combination of sodium carbonate and ascorbic acid, a combination of sodium hydroxide and sodium carbonate or a combination of lactic acid and ascorbic acid, etc.

[0014] As a preferred embodiment of the present invention, the concentration of the pore-expanding agent is 0.01–5 mol / L. The concentration can be 0.01 mol / L, 0.05 mol / L, 0.5 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, 3 mol / L, 3.5 mol / L, 4 mol / L, 4.5 mol / L, or 5 mol / L, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0015] As a preferred embodiment of the present invention, the mass ratio of the pore-expanding agent to the Y molecular sieve is (0.01-25):(0.01-30), wherein the mass ratio can be 0.01:0.01, 0.01:5, 0.01:10, 0.01:15, 0.01:20, 0.01:25, 0.01:30, 5:0.01, 5:5, 5:10, 5:15, 5:20, 5:25, 5:30, 10:0.01, 10:0.05, 10:15, 10:25, 10:30, 15:0.1, 15:5, 15:10, 15:20, 15:25, 15:30, 20:0.1, 20:5, 20:10, 20:15, 20:30, 25:0.1, 25:5, 25:10, 25:15, 25:20, 25:25, or 25:30, etc., but not limited to the listed values. Other unlisted values ​​within this range are also applicable, preferably (0.01~5):(0.01~6).

[0016] In this invention, an excessively high mass ratio of pore expander to molecular sieve will cause the framework to collapse, thereby reducing its CO2 adsorption performance. An excessively low mass ratio will result in a small contact area between the pore expander and the molecular sieve, leading to insufficient reaction and affecting the improvement of its CO2 adsorption performance.

[0017] As a preferred technical solution of the present invention, the mixing time is 0.01 to 36 hours, wherein the time can be 0.01 hours, 0.05 hours, 0.1 hours, 0.5 hours, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 5 hours, 10 hours, 15 hours, 20 hours, 25 hours, 30 hours, 35 hours or 35 hours, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable, preferably 0.01 to 3 hours.

[0018] As a preferred technical solution of the present invention, the calcination temperature is 40-1800℃, wherein the temperature can be 40℃, 50℃, 100℃, 150℃, 200℃, 250℃, 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃, 1000℃, 1100℃, 1200℃, 1300℃, 1400℃, 1500℃, 1600℃, 1700℃, or 1800℃, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable. Preferably, it is 40-950℃, and more preferably, it is 100-600℃.

[0019] If the calcination temperature is too high, the Y molecular sieve will be destroyed, resulting in energy waste; if the calcination temperature is too low, the pore-expanding agent cannot be completely removed.

[0020] As a preferred technical solution of the present invention, the calcination time is 0.1 to 24 hours, wherein the time can be 0.1 hours, 2 hours, 4 hours, 6 hours, 8 hours, 10 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours or 24 hours, etc., but is not limited to the listed values. Other unlisted values ​​within this range are also applicable, preferably 1 to 8 hours.

[0021] As a preferred technical solution of the present invention, the preparation method includes: mixing a pore-expanding agent with a concentration of 0.05-5 mol / L with a Y molecular sieve, and then calcining the mixture at 40-950°C for 0.1-24 h to obtain the Y molecular sieve adsorbent.

[0022] The pore-expanding agent includes any one or a combination of at least two of the following: sulfuric acid, hydrochloric acid, nitric acid, acetic acid, sodium hydroxide solution, potassium hydroxide solution, lactic acid, ammonia, malic acid, succinic acid, propionic acid, formic acid, sodium carbonate, amino acids, ascorbic acid, or sodium silicate.

[0023] A second objective of this invention is to provide a Y molecular sieve adsorbent, which is prepared by the preparation method described in one objective.

[0024] The third objective of this invention is to provide an application of the Y molecular sieve adsorbent described in the second objective, wherein the Y molecular sieve adsorbent is applied in the field of carbon dioxide adsorption materials.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The Y molecular sieve adsorbent prepared by the present invention achieves high-efficiency adsorption of carbon dioxide, and the carbon dioxide adsorption capacity can reach up to 6.1 mmol / g, which effectively solves the problem of low adsorption capacity of traditional Y molecular sieves.

[0027] (2) The preparation process of the Y molecular sieve adsorbent of the present invention is simple, low in cost and environmentally friendly, effectively solving the problem of complex preparation process of traditional Y molecular sieve adsorbent. Attached Figure Description

[0028] Figure 1 This is the adsorption isotherm diagram of the Y molecular sieve adsorbent prepared in Example 1 of the present invention. Detailed Implementation

[0029] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention.

[0030] Example 1

[0031] This embodiment provides a method for preparing an ascorbic acid-modified Y molecular sieve adsorbent, the preparation method comprising:

[0032] Ascorbic acid (2 mol / L) and Y molecular sieve powder were mixed at a mass ratio of 1:1 for 0.05 h to obtain a mixed product. The mixed product was then calcined at 550 °C for 5 h to obtain the pore-expanding agent modified Y molecular sieve adsorbent.

[0033] The adsorption isotherm of the Y molecular sieve adsorbent obtained in this embodiment is as follows: Figure 1 As shown.

[0034] Example 2

[0035] This embodiment provides a method for preparing a sodium carbonate-modified Y molecular sieve adsorbent, the preparation method comprising:

[0036] Sodium carbonate (2.5 mol / L) and Y molecular sieve powder were mixed at a mass ratio of 1:2 for 0.05 h to obtain a mixed product. The mixed product was then calcined at 500 °C for 4 h to obtain the pore-expanding agent-modified Y molecular sieve adsorbent.

[0037] Example 3

[0038] This embodiment provides a method for preparing a lactic acid-modified Y molecular sieve adsorbent, the preparation method comprising:

[0039] Lactic acid (2.5 mol / L) and Y molecular sieve powder were mixed at a mass ratio of 1:2.5 for 0.05 h to obtain a mixed product. The mixed product was then calcined at 450 °C for 3 h to obtain the pore-expanding agent-modified Y molecular sieve adsorbent.

[0040] Example 4

[0041] In this embodiment, all conditions are the same as in Example 2, except that the concentration of sodium carbonate is replaced with 1 mol / L.

[0042] Example 5

[0043] In this embodiment, all conditions are the same as in Example 2, except that the concentration of sodium carbonate is replaced with 0.5 mol / L.

[0044] Example 6

[0045] In this embodiment, all conditions are the same as in Example 2, except that the calcination temperature is replaced with 100°C.

[0046] Example 7

[0047] In this embodiment, all conditions are the same as in Example 2, except that the calcination temperature is replaced with 1800℃.

[0048] Example 8

[0049] In this embodiment, all conditions are the same as in Example 2, except that sodium carbonate is replaced with sulfuric acid.

[0050] Example 9

[0051] In this embodiment, all conditions are the same as in Example 2, except that the mass ratio of sodium carbonate to Y molecular sieve powder is replaced with 0.01:7.

[0052] Example 10

[0053] In this embodiment, all conditions are the same as in Example 2, except that the mass ratio of sodium carbonate to Y molecular sieve powder is replaced with 6:0.01.

[0054] Comparative Example 1

[0055] The conditions in this comparative example are the same as in Example 2, except that sodium carbonate is replaced with oxalic acid.

[0056] Comparative Example 2

[0057] The conditions in this comparative example are the same as in Example 2, except that sodium carbonate, the pore-expanding agent, is not used.

[0058] Comparative Example 3

[0059] The only difference between this comparative example and Example 2 is that the Y molecular sieve was replaced with ZSM-5 molecular sieve.

[0060] The CO2 adsorption performance of the Y molecular sieve adsorbents prepared in Examples 1-10 and Comparative Examples 1-3 was tested, and the test results are shown in Table 1.

[0061] Among them, the CO2 adsorption capacity was tested by using a high-precision JWGB-BK300 gas adsorption instrument to collect CO2 adsorption isotherms. The sample was degassed at 573K for 10 hours, and then the CO2 adsorption capacity at 298K and 1 bar was tested.

[0062] Table 1

[0063]

[0064]

[0065] As shown in Table 1, as can be seen from Examples 1-3, the present invention uses a mixed modification and calcination process to prepare a Y molecular sieve modified with a pore-expanding agent with excellent adsorption performance. The preparation process is simple, low-cost and environmentally friendly. As can be seen from the table data, the Y molecular sieve adsorbent of this application achieves high-efficiency adsorption of CO2, effectively solving the problems of low adsorption capacity and complex preparation process of Y molecular sieve.

[0066] As can be seen from the comparison between Examples 4-5 and Example 2, the concentration of sodium carbonate decreases or increases, and the amount of carbon dioxide adsorbed decreases.

[0067] A comparison between Examples 6-7 and Example 2 shows that the amount of carbon dioxide adsorbed decreases when the calcination temperature is too high or too low.

[0068] As can be seen from the comparison between Example 8 and Example 2, when sodium carbonate is replaced with sulfuric acid, the carbon dioxide adsorption capacity of the prepared Y molecular sieve decreases. The preferred pore-expanding agent of the present invention is at least one of sodium hydroxide, lactic acid, amino acids, sodium carbonate or ascorbic acid.

[0069] As can be seen from the comparison between Example 9 and Example 2, replacing the mass ratio of sodium carbonate to Y molecular sieve powder with 1:6 reduces the mass ratio of sodium carbonate to Y-type powder, which leads to a decrease in the contact area between sodium carbonate and molecular sieve, resulting in insufficient reaction and insignificant effect on improving CO2 adsorption performance.

[0070] A comparison between Example 10 and Example 2 shows that, except for replacing the mass ratio of sodium carbonate to Y molecular sieve powder with 5:1, the mass ratio of sodium carbonate to Y-type powder increases, which accelerates the reaction mass transfer rate, leading to the collapse of Si / Al in the Y molecular sieve framework and reducing the CO2 adsorption capacity.

[0071] As can be seen from the comparison between Comparative Example 1 and Example 2, when sodium carbonate is replaced with oxalic acid, which is not a pore-forming agent but an acidic solution, oxalic acid removes Si / Al from the framework of Y molecular sieve during the reaction, resulting in a decrease in CO2 adsorption performance.

[0072] As can be seen from the comparison between Comparative Example 2 and Example 2, the CO2 adsorption performance did not increase without the use of sodium carbonate as a pore-expanding agent.

[0073] As can be seen from the comparison between Comparative Example 3 and Example 2, the preparation method of the Y molecular sieve adsorbent of the present invention has a more significant improvement effect on the adsorption performance compared with other molecular sieves.

[0074] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. An application of a Y molecular sieve adsorbent in CO2 adsorption, characterized in that, The Y molecular sieve adsorbent is prepared by the following method, which includes: mixing a pore-expanding agent and a Y molecular sieve, and then calcining to obtain the Y molecular sieve adsorbent; The pore-expanding agent includes any one or a combination of at least two of lactic acid, sodium carbonate, or ascorbic acid; The concentration of the pore-expanding agent is 1-2.5 mol / L; The mass ratio of the pore-expanding agent to the Y molecular sieve is 1:(1~2.5). The calcination temperature is 450-550℃; The calcination time is 3-5 hours.

2. The application according to claim 1, characterized in that, The mixing time is 0.01~36h.

3. The application according to claim 2, characterized in that, The mixing time is 0.01~3h.

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