Preparation method of composite material for adsorbing VOCs in aviation kerosene

Abstract

The application belongs to the technical field of composite molecular sieve, and provides a preparation method of composite material for VOCs adsorption in aviation kerosene, comprising the following steps: S1, preparing a Beta molecular sieve suspension; S2, adjusting the Beta molecular sieve suspension; S3, reaction and in-situ growth; and S4, separating and drying solid ZSM-5 molecular sieve. The preparation method of the composite material adopts ZSM-5 molecular sieve in-situ growth technology on the Beta molecular sieve, and compared with the preparation process of a traditional adsorbent, the composite material prepared by the application has better adsorption capacity, the preparation method is more environmentally friendly, no harmful waste is generated in the preparation process, and the risk of secondary pollution is reduced.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of composite molecular sieves, in particular to a preparation method of a composite material for adsorbing VOCs in aviation kerosene. BACKGROUND

[0002] Aviation kerosene is one of the main energy sources for airplanes, and the volatile organic compounds (VOCs) emitted during storage and transportation of aviation kerosene pose potential threats to the environment and health. Therefore, it is crucial to develop efficient VOCs removal technologies for aviation kerosene. Currently, adsorption methods are widely used to remove VOCs in aviation kerosene. The performance of adsorbents directly affects the removal efficiency, so finding new adsorbent materials has become one of the research focuses.

[0003] Previous studies have shown that traditional adsorbents such as activated carbon and silica gel can remove VOCs in aviation kerosene to some extent. However, these traditional adsorbents have some limitations in selectivity, adsorption capacity and cyclic stability. Therefore, researchers have been exploring new adsorbent materials to overcome these limitations and improve removal efficiency.

[0004] In recent years, Beta and ZSM-5 composite molecular sieves have attracted widespread attention. These composite molecular sieves are a special type of adsorbent material with highly controllable pore structure and surface chemical properties, which can be customized and improved as needed. In the field of aviation kerosene VOCs removal, Beta and ZSM-5 composite molecular sieves are favored by researchers as new adsorbent materials. These materials not only have high selectivity and adsorption capacity, but also can achieve good cyclic stability.

[0005] Therefore, it is an important task to develop a new adsorbent material, especially a composite adsorbent material based on Beta and ZSM-5 composite molecular sieves, to improve the removal efficiency of aviation kerosene VOCs. The invention patent CN2015102243426 discloses a method for preparing Beta and ZSM-5 composite molecular sieves using hard template technology. This technology has high complexity and high preparation cost, which is not conducive to batch production and energy consumption control. The preparation method disclosed in the present application is more environmentally friendly and economically valuable, and is expected to make a major breakthrough in the field of aviation fuel processing. By fully utilizing the advantages of Beta and ZSM-5 composite molecular sieves, a more efficient and sustainable aviation kerosene VOCs removal process can be achieved. SUMMARY

[0006] The preparation method of the composite material for adsorbing VOCs in aviation kerosene of the present application is used to solve the technical problems related in the background art.

[0007] The technical scheme provided by the present application is as follows: a preparation method of a composite material for adsorbing VOCs in aviation kerosene, comprising the following steps:

[0008] S1, preparing a Beta molecular sieve suspension: Beta molecular sieve powder is taken and added into distilled water, and stirred to prepare a Beta molecular sieve suspension with a concentration of 0.1-1 g / mL;

[0009] S2, adjusting the Beta molecular sieve suspension: a silicon source solution with a concentration of 0.1-0.5 g / mL, an aluminum source solution with a concentration of 0.05-0.2 g / mL and a basic reagent solution with a concentration of 0.01-0.1 g / mL are taken and added into the Beta molecular sieve suspension prepared in step S1, and stirred at the same time;

[0010] S3, reaction and in-situ growth: the Beta molecular sieve suspension adjusted in step S2 is put into a reactor, and reacted at 120 DEG C for 24 hours to promote the in-situ growth of ZSM-5 molecular sieve on the Beta molecular sieve;

[0011] S4, separating and drying the solid ZSM-5 molecular sieve: the Beta molecular sieve suspension is separated after being cooled to obtain the solid ZSM-5 molecular sieve, and the solid ZSM-5 molecular sieve is dried to obtain ZSM-5 molecular sieve raw powder.

[0012] In some embodiments, in steps S1-S2, the concentration of the Beta molecular sieve suspension is 0.5 g / mL, the concentration of the silicon source solution is 0.25 g / mL, the concentration of the aluminum source solution is 0.1 g / mL, and the concentration of the basic reagent solution is 0.05 g / mL.

[0013] In some embodiments, in step S1, the Beta molecular sieve powder is 30-50 mesh.

[0014] In some embodiments, in step S1, the stirring speed is 200-300 rpm.

[0015] In some embodiments, in step S2, the silicon source solution is a silicate solution.

[0016] In some embodiments, in step S2, the aluminum source solution is an aluminate solution.

[0017] In some embodiments, in step S2, the basic reagent solution is a sodium hydroxide solution.

[0018] In some embodiments, in step S2, the addition speed of the silicon source solution is 1 mL / min, the addition speed of the aluminum source solution is 0.5 mL / min, and the addition speed of the basic reagent solution is 0.25 mL / min.

[0019] In some embodiments, in step S4, the obtained solid ZSM-5 molecular sieve is placed in an oven at a temperature of 110 DEG C for 5 hours of continuous drying.

[0020] In some embodiments, in step S4, the obtained ZSM-5 molecular sieve powder is ground to a desired particle size.

[0021] Compared with the prior art, the present application has the following advantages:

[0022] (1) The composite material preparation method of the present application can prepare Beta / ZSM-5 composite molecular sieve, which has higher selectivity and adsorption capacity than traditional adsorbents such as activated carbon and silica gel due to the special structure of ZSM-5 molecular sieve, and can more effectively capture volatile organic compounds (VOCs) in aviation kerosene, thereby improving the adsorption efficiency.

[0023] (2) The composite material preparation method of the present application can prepare Beta / ZSM-5 composite molecular sieve, which has excellent cycle stability compared with traditional adsorbents such as activated carbon and silica gel, and can maintain stable adsorption performance and is not prone to deactivation during multiple adsorption and regeneration processes, thereby having a more durable service life.

[0024] (3) The composite material preparation method of the present application uses ZSM-5 molecular sieve partial in-situ growth technology on Beta molecular sieve, which can adjust the performance of the composite adsorbent material according to application requirements to meet the removal requirements of different volatile organic compounds.

[0025] (4) The composite material preparation method of the present application uses ZSM-5 molecular sieve partial in-situ growth technology on Beta molecular sieve, which has better adsorption capacity of the composite material prepared by the present application compared with the preparation process of traditional adsorbents, and the preparation method is more environmentally friendly, and no harmful waste is generated during the preparation process, thereby reducing the risk of secondary pollution. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a flowchart of the composite material preparation method of the present application. DETAILED DESCRIPTION

[0027] The present application will be further described in detail below in conjunction with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0028] It should be noted that the terms "first", "second" and the like in the description and in the claims of the present application and the above-mentioned accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific sequence or chronology. It should be understood that the data thus used can be interchanged, where appropriate, so that the embodiments of the present application described herein can be implemented. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or apparatus that includes a list of steps or units is not necessarily limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to such processes, methods, products or apparatus.

[0029] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not intended to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0030] Embodiment 1

[0031] S1, preparation of Beta molecular sieve suspension: 100 g of Beta molecular sieve powder was added to 100 mL of distilled water and stirred to prepare a Beta molecular sieve suspension with a concentration of 1 g / mL;

[0032] S2, adjustment of Beta molecular sieve suspension:

[0033] 50 g of sodium silicate was dissolved in 100 mL of distilled water to prepare a silicon source solution with a concentration of 0.5 g / mL;

[0034] 20 g of aluminum nitrate was dissolved in 100 mL of distilled water to prepare an aluminum source solution with a concentration of 0.2 g / mL;

[0035] 1 g of sodium hydroxide was dissolved in 100 mL of distilled water to prepare a 0.1 g / mL alkaline reagent solution;

[0036] The prepared silicon source solution was added to the Beta molecular sieve suspension prepared in step S1 at a rate of 1 mL / min, the aluminum source solution at a rate of 0.5 mL / min, and the alkaline reagent solution at a rate of 0.25 mL / min, while stirring;

[0037] S3, reaction and in-situ growth: the adjusted Beta molecular sieve suspension in step S2 was placed in a reactor, the suspension was continuously stirred, and the reaction was carried out at 120°C for 24 hours to promote the in-situ growth of ZSM-5 molecular sieve on the Beta molecular sieve;

[0038] S4, separating and drying the solid ZSM-5 zeolite: after the reaction is completed, the Beta zeolite suspension is cooled to room temperature, and then separated by a centrifuge to obtain a solid ZSM-5 zeolite, which is placed in an oven for drying at a temperature of 110°C for 5 hours to obtain ZSM-5 zeolite raw powder; finally, the obtained ZSM-5 zeolite raw powder is ground to a desired particle size.

[0039] The test parameters of the ZSM-5 zeolite obtained in this example are shown in Table 1 below.

[0040] Example 2

[0041] S1, preparing a Beta zeolite suspension: 50g of Beta zeolite powder is added to 100mL of distilled water and stirred to prepare a Beta zeolite suspension with a concentration of 0.5;

[0042] S2, adjusting the Beta zeolite suspension:

[0043] 25g of sodium silicate is dissolved in 100mL of distilled water to prepare a silicon source solution with a concentration of 0.25g / mL;

[0044] 10g of aluminum nitrate is dissolved in 100mL of distilled water to prepare an aluminum source solution with a concentration of 0.1g / mL;

[0045] 5g of sodium hydroxide is dissolved in 100mL of distilled water to prepare a basic reagent solution with a concentration of 0.05g / mL;

[0046] The prepared silicon source solution is added to the Beta zeolite suspension prepared in step S1 at a speed of 1mL / min, the aluminum source solution at a speed of 0.5mL / min, and the basic reagent solution at a speed of 0.25mL / min, while stirring;

[0047] S3, reaction and in-situ growth: the adjusted Beta zeolite suspension in step S2 is placed in a reactor, the suspension is continuously stirred, and the suspension is reacted at 120°C for 24 hours to promote the in-situ growth of ZSM-5 zeolite on the Beta zeolite;

[0048] S4, separating and drying the solid ZSM-5 zeolite: after the reaction is completed, the Beta zeolite suspension is cooled to room temperature, and then separated by a centrifuge to obtain a solid ZSM-5 zeolite, which is placed in an oven for drying at a temperature of 110°C for 5 hours to obtain ZSM-5 zeolite raw powder; finally, the obtained ZSM-5 zeolite raw powder is ground to a desired particle size.

[0049] The test parameters of the ZSM-5 molecular sieve obtained in this example are shown in Table 1 below.

[0050] Example 3

[0051] S1, preparation of a Beta molecular sieve suspension: 10 g of Beta molecular sieve powder was added to 100 mL of distilled water and stirred to prepare a Beta molecular sieve suspension with a concentration of 0.1 g / mL;

[0052] S2, adjustment of the Beta molecular sieve suspension:

[0053] 10 g of sodium silicate was dissolved in 100 mL of distilled water to prepare a silicon source solution with a concentration of 0.1 g / mL;

[0054] 5 g of aluminum nitrate was dissolved in 100 mL of distilled water to prepare an aluminum source solution with a concentration of 0.05 g / mL;

[0055] 10 g of sodium hydroxide was dissolved in 100 mL of distilled water to prepare a basic reagent solution with a concentration of 0.1 g / mL;

[0056] The prepared silicon source solution was added to the Beta molecular sieve suspension prepared in step S1 at a rate of 1 mL / min, the aluminum source solution at a rate of 0.5 mL / min, and the basic reagent solution at a rate of 0.25 mL / min, while stirring;

[0057] S3, reaction and in-situ growth: the adjusted Beta molecular sieve suspension in step S2 was placed in a reactor, the suspension was continuously stirred, and the suspension was reacted at 120°C for 24 hours to promote the in-situ growth of ZSM-5 molecular sieve on the Beta molecular sieve;

[0058] S4, separation and drying of solid ZSM-5 molecular sieve: after the reaction was completed, the Beta molecular sieve suspension was cooled to room temperature, then separated by a centrifuge to obtain a solid ZSM-5 molecular sieve, which was placed in an oven for drying at a temperature of 110°C for 5 hours to obtain ZSM-5 molecular sieve raw powder; finally, the obtained ZSM-5 molecular sieve raw powder was ground to the desired particle size.

[0059] The test parameters of the ZSM-5 molecular sieve obtained in this example are shown in Table 1 below.

[0060] Comparative Example 1

[0061] (1) Weigh 0.05 g of sodium hydroxide into 6.75 g of tetraethylammonium hydroxide (abbreviation: (TEA)2O, 35 wt% aqueous solution), add 8.925 g of silica sol (containing 30 wt% silica aqueous solution) drop by drop, stir at room temperature until the silica sol is completely dissolved, add 0.185 g of aluminum isopropoxide 98 wt%, the silica sol is calculated as SiO2, and the aluminum isopropoxide is calculated as Al2O3, so that the molar ratio of each material is: SiO2: Al2O3: (TEA)2O: Na2O: H2O = 25: 0.25: 9: 0.35: 330, continue to stir at room temperature for 12 hours; filter with a needle filter with a filtration precision of 200 nm to prepare a clear Beta zeolite growth solution.

[0062] (2) Weigh 0.05 g of sodium hydroxide into 5.85 g of tetrapropylammonium hydroxide (abbreviation: (TPA)2O, 40 wt% aqueous solution); add 9.275 g of silica sol (containing 30 wt% silica aqueous solution) drop by drop, stir at room temperature until the silica sol is completely dissolved, add 0.095 g of aluminum isopropoxide (98 wt%), the silica sol is calculated as SiO2, and the aluminum isopropoxide is calculated as Al2O3, so that the molar ratio of each material is: SiO2: Al2O3: (TPA)2O: Na2O: H2O = 25: 0.25: 6.25: 0.35: 450, continue to stir at room temperature for 12 hours; filter with a needle filter with a filtration precision of 200 nm to prepare a clear ZSM-5 zeolite growth solution.

[0063] (3) Weigh 0.2 g of mesoporous carbon with a three-dimensionally ordered mesoporous structure into 15 ml of the Beta zeolite growth solution, the mesoporous carbon has a mesopore size of 40 nm, and after standing at room temperature for 30 minutes, transfer into a polytetrafluoroethylene-lined stainless steel reaction kettle with a volume of 25 ml, place the stainless steel reaction kettle in a constant-temperature oven, and perform hydrothermal crystallization at 100°C for 96 hours; filter the product according to a conventional operation, wash with deionized water, and obtain the mesoporous carbon containing Beta zeolite seeds.

[0064] (4) Disperse the product washed in step (3) in 10 ml of a 0.001 mol / L sodium hydroxide solution; perform alkali washing at 70°C for 6 hours; filter the product according to a conventional operation, wash with deionized water, and obtain the mesoporous carbon containing Beta zeolite seeds in the mesopores.

[0065] (5) Soak the product after alkali washing in 15 ml of the ZSM-5 zeolite growth solution, stand at room temperature for 30 minutes, and then transfer into a polytetrafluoroethylene-lined stainless steel reaction kettle with a volume of 25 ml, place the stainless steel reaction kettle in a constant-temperature oven, and perform hydrothermal crystallization at 100°C for 48 hours; filter the product according to a conventional operation, wash with deionized water, and obtain the mesoporous carbon containing Beta and ZSM-5 zeolite seeds in the mesopores.

[0066] (6) repeat the operation of steps (3) (4) (5) 2 times in order, and the product is filtered and washed repeatedly with deionized water according to conventional operation; the washed product is placed in a constant temperature oven at 70℃ for drying for 12 hours, and the dried product is calcined in a muffle furnace, with an initial temperature of room temperature, a temperature rising rate of 1℃ / min, and calcination at 550℃ for 6 hours, to obtain spherical Beta / ZSM-5 nanocomposite molecular sieves with equal particle size.

[0067] The test parameters of the Beta / ZSM-5 nanocomposite molecular sieves prepared in Comparative Example 1 are shown in Table 1.

[0068] The adsorption capacity test in Table 1 is carried out in a fixed bed reactor connected with a gas chromatograph, with gaseous aviation kerosene as a reference. The front probe of the gas chromatograph is equipped with a hydrogen flame ionization detector and a thermal conductivity detector. During the test experiment, 100 mg of the sample to be tested is placed in the reaction tube, and the sample is treated at 200℃ for 12 h to remove water and impurities in the sample before the adsorption reaction; aviation kerosene is evaporated by heating, and the aviation kerosene vapor is measured at a rate of 100 mL / min, and the concentration of the aviation kerosene is 400 ppm; and the saturated adsorption capacity of the sample to the aviation kerosene is determined.

[0069] Adsorption capacity calculation formula:

[0070]

[0071] Wherein:

[0072] F is the flow rate of aviation kerosene

[0073] C0is the initial aviation kerosene concentration mg / m 3

[0074] C t is the aviation kerosene concentration mg / m after t minutes 3

[0075] t is the adsorption time

[0076] t s is the saturated adsorption time

[0077] Table 1

[0078]

[0079]

[0080] As can be seen from Table 1, the ZSM-5 molecular sieve prepared by the aviation kerosene VOCs adsorbing composite material preparation method of the present application has a significantly improved adsorption capacity for adsorbing VOCs in aviation kerosene under the same reaction conditions compared with Comparative Example 1, and good technical effects are achieved.

[0081] The above descriptions are only the preferred embodiments of the present application, and are not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a composite material for adsorbing VOCs in aviation kerosene, characterized in that, The method comprises the following steps: S1, preparing a Beta zeolite suspension: Beta zeolite powder is taken and added to distilled water, and stirred to prepare a Beta zeolite suspension with a concentration of 0.1-1 g / mL; wherein the stirring speed is 200-300 rpm; S2, adjusting the Beta zeolite suspension: a silicon source solution with a concentration of 0.1-0.5 g / mL, an aluminum source solution with a concentration of 0.05-0.2 g / mL, and a basic reagent solution with a concentration of 0.01-0.1 g / mL are taken and added to the Beta zeolite suspension prepared in step S1, and stirring is simultaneously performed; wherein the addition speed of the silicon source solution is 1 mL / min, the addition speed of the aluminum source solution is 0.5 mL / min, and the addition speed of the basic reagent solution is 0.25 mL / min; S3, reaction and in-situ growth: the Beta zeolite suspension adjusted in step S2 is placed in a reactor and reacted at 120℃ for 24 hours to promote the in-situ growth of ZSM-5 zeolite on the Beta zeolite; S4, separating and drying the solid ZSM-5 zeolite: the Beta zeolite suspension is separated after cooling to obtain the solid ZSM-5 zeolite, and the obtained solid ZSM-5 zeolite is placed in an oven with a temperature of 110℃ for continuous drying for 5 hours to obtain ZSM-5 zeolite raw powder.

2. The composite material production method according to claim 1, wherein In steps S1-S2, the concentration of the Beta zeolite suspension is 0.5 g / mL, the concentration of the silicon source solution is 0.25 g / mL, the concentration of the aluminum source solution is 0.1 g / mL, and the concentration of the basic reagent solution is 0.05 g / mL.

3. The composite material production method according to claim 1, wherein In step S1, the Beta zeolite powder is 30-50 mesh.

4. The composite material production method according to claim 1, wherein In step S2, the silicon source solution is a silicate solution.

5. The composite material production method according to claim 1, wherein In step S2, the aluminum source solution is an aluminate solution.

6. The composite material production method according to claim 1, wherein In step S2, the basic reagent solution is a sodium hydroxide solution.

7. The composite material production method according to claim 1, wherein In step S4, the obtained ZSM-5 zeolite raw powder is further ground to a desired particle size.

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