Functional photo-thermal rare earth aerogel capable of being used for efficiently treating high-viscosity crude oil wastewater and preparation method of functional photo-thermal rare earth aerogel

Abstract

The invention discloses functional photo-thermal rare earth aerogel capable of being used for efficiently treating high-viscosity crude oil wastewater and a preparation method of the functional photo-thermal rare earth aerogel. The preparation method of the aerogel material comprises the following steps: (1) preparing a carboxylated nanocellulose solution (CNF-C) suspension with a certain concentration under a room temperature condition, then adding rare earth (Pr6O11), stirring at a constant temperature under a hydrothermal condition, and cooling to room temperature to obtain a mixed suspension; (2) carrying out ultrasonic treatment on the mixed suspension by using an ultrasonic cell crusher to remove tiny bubbles in the mixed suspension, carrying out pre-freezing treatment, and then carrying out freeze-drying treatment, so as to obtain a CNF-C / Pr6O11 aerogel precursor; and (3) carrying out hydrophobic modification on the CNF-C / Pr6O11 aerogel precursor by adopting a solution impregnation method, and carrying out vacuum drying, so as to obtain the functional photo-thermal rare earth aerogel (CNF-C / Pr6O11) capable of efficiently separating the high-viscosity crude oil wastewater. The method disclosed by the invention is simple, low in cost and wide in raw material source, has relatively good oil-water separation capacity on high-viscosity crude oil under a photo-thermal condition, and can be recycled for multiple times through simple compression regeneration. In addition, the problems that in the high-viscosity crude oil wastewater treatment process, a traditional separation material is low in efficiency, high in energy consumption and prone to being influenced by the viscosity of crude oil are solved, and meanwhile a new thought is provided for high-added-value application and development of rare earth and structural design of functional materials.

Description

Technical Field

[0001] This invention relates to the field of oil-water separation aerogels, specifically to a functional photothermal rare earth aerogel that can be used for the efficient treatment of high-viscosity crude oil wastewater and its preparation method. Background Technology

[0002] With the rapid development of global industrialization, the large amounts of high-viscosity crude oil wastewater generated during oil extraction, refining, and transportation have become a serious environmental problem. High-viscosity crude oil wastewater has a complex composition, containing large amounts of heavy components such as gums and asphaltenes. Its high viscosity and stability result in low efficiency, high energy consumption, and susceptibility to the physical properties of crude oil in traditional oil-water separation technologies. Currently, common separation methods include gravity sedimentation, centrifugation, adsorption materials, and membrane separation technologies. However, these methods generally suffer from low separation efficiency, complex operation, easy material contamination, and difficulty in regeneration when treating high-viscosity crude oil.

[0003] In recent years, photothermal materials have shown broad application prospects in the field of oil-water separation. By converting solar energy into thermal energy, photothermal materials can locally heat high-viscosity crude oil, significantly reducing its viscosity and thus improving separation efficiency. However, existing photothermal materials still face challenges such as limited photothermal conversion efficiency, poor cycle stability, complex preparation processes, and high costs. In addition, traditional adsorption materials such as activated carbon and metal foam are prone to clogging in high-viscosity environments and have poor regeneration performance, making it difficult to meet the needs of practical applications.

[0004] Aerogel materials are considered ideal carriers for oil-water separation due to their high porosity, low density, and large specific surface area. However, conventional aerogel materials still have shortcomings in terms of photothermal properties and adaptability to high-viscosity crude oil. Rare earth elements have attracted widespread attention in functional materials design due to their unique electronic structure and excellent optical and catalytic properties. Among them, Pr6O... 11 As an important rare earth oxide, it has good photothermal conversion ability and chemical stability, but its application in the field of high viscosity crude oil separation has not been fully explored.

[0005] Therefore, developing a functional aerogel material with high-efficiency photothermal conversion performance, superhydrophobic properties, and excellent cycle stability is of significant scientific importance and application value for solving the problem of high-viscosity crude oil wastewater treatment. This invention utilizes carboxylated nanocellulose (CNF-C) and rare earth Pr6O... 11 By combining composite materials with hydrophobic modification processes, a novel photothermal rare earth aerogel was successfully prepared, providing a new material and method for achieving efficient and low-energy separation of high-viscosity crude oil. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing high-viscosity crude oil wastewater treatment technologies, such as low separation efficiency, high energy consumption, easy material contamination, and difficulty in regeneration, and to provide a functional photothermal rare earth aerogel with high efficiency photothermal conversion performance, superhydrophobic properties, and excellent cycle stability, as well as its preparation method.

[0007] The technical solution adopted in this invention is to provide a functional photothermal rare earth aerogel that can be used for the efficient treatment of high-viscosity crude oil wastewater. This aerogel uses carboxylated nanocellulose (CNF-C) as a three-dimensional framework matrix, and incorporates rare earth oxides (Pr6O4) with excellent photothermal conversion properties. 11 Pr6O was prepared by hydrophobic modification. The material possesses a rich hierarchical porous structure and exhibits both superhydrophobic (water contact angle greater than 150°) and superoleophilic (oil contact angle 0°) surface properties. Under light irradiation, Pr6O… 11 It can efficiently convert light energy into heat energy, achieving localized heating of high-viscosity crude oil in the contact area, significantly reducing its viscosity, thereby greatly improving the adsorption and permeation rate of crude oil and achieving efficient oil-water separation. The separated aerogel material can be regenerated through simple mechanical compression, restoring its porous structure and adsorption properties, and can be recycled multiple times.

[0008] The present invention achieves the above objectives using the following technical solutions:

[0009] A functional photothermal rare earth aerogel for efficient treatment of high-viscosity crude oil wastewater and its preparation method thereof, comprising the following steps:

[0010] 1) Prepare a carboxylated nanocellulose (CNF-C) suspension by adding praseodymium oxide (Pr6O) under constant temperature and continuous stirring. 11 Add the powder and continue stirring to ensure complete reaction; after the reaction is complete, cool to room temperature and remove the tiny air bubbles in the suspension using an ultrasonic cell disruptor to obtain a mixed suspension;

[0011] 2) The mixed suspension obtained in step 1) is placed in an ultra-low temperature freezer for pre-freezing treatment, and then freeze-dried in a freeze dryer to obtain CNF-C / Pr6O. 11 Aerogel precursor;

[0012] 3) The CNF-C / Pr6O obtained in step 2) was subjected to a solution impregnation method. 11 The aerogel precursor is hydrophobically modified. After hydrophobic modification, the material is taken out and dried in a vacuum drying oven to obtain a functional photothermal rare earth aerogel that can be used for the efficient treatment of high-viscosity crude oil wastewater.

[0013] To further achieve the objectives of this invention, as a preferred technical solution, in step 1), the mass concentration of the carboxylated nanocellulose (CNF-C) suspension is 0.1wt% to 3.0wt%, and the amount added is 10 to 100g; praseodymium oxide (Pr6O) 11 The mass of powder added is 0.01 to 0.30 g.

[0014] As a preferred technical solution, in step 1), the magnetic stirrer has a rotation speed of 100-600 rpm / min, a stirring temperature of 40-80℃, and a stirring time of 1-8h; the ultrasonic cell disruptor has an ultrasonic power of 100-1000W and an ultrasonic time of 10-180min.

[0015] As a preferred technical solution, in step 2), the pre-freezing temperature of the ultra-low temperature freezer is -25 to -5℃, and the pre-freezing time is 0.5 to 3.0 h; the freeze dryer is set to a freeze-drying temperature of -120 to -50℃, and the freeze-drying time is 2 to 24 h; the purpose of the pre-freezing treatment is to prevent the mixed suspension from breaking during the freeze-drying process; secondly, it can make the aerogel more plastic.

[0016] As a preferred technical solution, in step 3), the solute of the hydrophobic solvent is a silane coupling agent or isocyanate, such as heptadecafluorodecyltrimethoxysilane, tridecafluorooctyltrimethoxysilane, octadecyltrichlorosilane, hexadecyltrimethoxysilane, hexamethylene diisocyanate, diphenylmethane diisocyanate, etc. Preferably, the solvent for the octadecyltrichlorosilane (OTS) hydrophobic agent is one of ketones, esters, ethers, benzene, or aromatic hydrocarbons; n-hexane is preferred. The solution impregnation method is used to modify the aerogel for hydrophobicity, which is simple and easy to operate, and has a good hydrophobic effect.

[0017] As a preferred technical solution, in step 3), the mass concentration of the hydrophobic agent is 0.1–2.0 wt%; the hydrophobic modification temperature is 25–80℃, and the hydrophobic modification time is 0.5–6.0 h. During the hydrophobic modification process, the temperature must be strictly controlled. If the temperature is too low, the hydrophobic modification efficiency will be low, and the hydrophobic properties of the aerogel will be poor. If the temperature is too high, the carboxyl bonds inside the carboxylated nanocellulose (CNF-C) will break, affecting the stability of the aerogel 3D skeleton and resulting in a poor morphological structure.

[0018] As a preferred technical solution, in step 3), the temperature of the vacuum drying oven is set to 30-80℃, and the hydrophobic modified aerogel material is dried for 0.5-6.0h.

[0019] A functional photothermal rare earth aerogel, which can be used for the efficient treatment of high-viscosity crude oil wastewater, is prepared by the above method. The functional photothermal rare earth aerogel has a porous structure, a water contact angle of more than 150° and an oil contact angle of 0° in air, and has excellent superhydrophobic / superoleophilic properties.

[0020] The application of the aforementioned functional photothermal rare earth aerogel in the efficient treatment of high-viscosity crude oil wastewater.

[0021] The functional photothermal rare earth aerogel described in this invention has a porous structure, with a water contact angle exceeding 150° and an oil contact angle of 0° in air. It exhibits superhydrophobic / superoleophilic properties and can effectively separate high-viscosity crude oil and water mixtures.

[0022] Compared with the prior art, the present invention has the following significant advantages and beneficial effects:

[0023] 1. High efficiency in photothermal conversion and viscosity reduction: Rare earth Pr6O 11 The introduction of this technology endows aerogels with excellent photothermal properties. Under light irradiation, the material can heat up rapidly, effectively reducing the viscosity of high-viscosity crude oil and overcoming the bottleneck problems of poor permeability and low efficiency of traditional adsorption materials when treating high-viscosity fluids.

[0024] 2. Excellent separation performance and selectivity: Through precise hydrophobic modification, the material possesses superhydrophobic / superoleophilic properties, enabling it to efficiently and selectively adsorb the oil phase while repelling the water phase, thus achieving efficient oil-water separation.

[0025] 3. Excellent structural stability and recyclability: The three-dimensional network structure constructed with carboxylated nanocellulose (CNF-C) endows the aerogel with excellent mechanical flexibility and structural stability. After adsorption saturation, crude oil can be discharged through simple physical extrusion, and the material structure can be restored, enabling multiple recycling and reducing operating costs.

[0026] 4. Simple preparation process, low cost, and environmentally friendly: The preparation method of this invention is simple, the reaction conditions are mild, and the nanocellulose raw materials used are widely available, renewable, and biodegradable, which meets the requirements of green chemistry and sustainable development.

[0027] 5. Providing a new approach for the high-value application of rare earth elements: This invention utilizes rare earth Pr6O 11 Its innovative application in oil-water separation aerogel materials expands the application field of rare earth functional materials and provides new ideas for the high-value-added development of rare earth resources. Attached Figure Description

[0028] Figure 1 CNF-C / Pr6O prepared in Example 2 of this invention 11 Flowchart of aerogel preparation

[0029] Figure 2 CNF-C / Pr6O prepared in Example 2 of this invention 11 X-ray diffraction pattern of aerogel.

[0030] Figure 3 CNF-C / Pr6O prepared in Example 2 of this invention 11 Fourier transform infrared spectrum of aerogel.

[0031] Figure 4 CNF-C / Pr6O prepared in Example 2 of this invention 11 Electron micrograph of aerogel.

[0032] Figure 5 Under photothermal conditions, crude oil droplets and water droplets were respectively dropped onto the non-hydrophobic and hydrophobic CNF-C / Pr6O prepared in Example 2 of this invention. 11 Images of the surface and cross-section wettability of aerogels.

[0033] Figure 6 (a) is CNF-C / Pr6O prepared in Example 2 of this invention. 11 Adsorption performance of aerogel on high-viscosity crude oil under different light intensities; Figure 6 (b) is CNF-C / Pr6O prepared in Example 2 of this invention. 11 A diagram illustrating the adsorption process of crude oil by aerogel. Figure 7 (a) CNF-C / Pr6O was prepared by extrusion according to Example 2 of the present invention. 11 The process by which aerogels recover their elastic deformation; Figure 7 (b) is CNF-C / Pr6O prepared by extrusion in Example 2 of this invention. 11 A comparison of the height of the aerogel before and after.

[0034] Figure 8 CNF-C / Pr6O prepared in Example 2 of this invention 11 Image showing the adsorption-desorption cycle performance of aerogel on high-viscosity crude oil. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to specific embodiments, but the implementation of the present invention is not limited thereto. Those skilled in the art can make appropriate adjustments to the following embodiments without departing from the core idea of ​​the present invention.

[0036] Example 1:

[0037] 1) Prepare a 0.1 wt% carboxylated nanocellulose (CNF-C) suspension. Weigh 80 g of the carboxylated nanocellulose (CNF-C) suspension and stir continuously in a constant temperature water bath at 400 rpm and 65℃. Slowly add 0.1 g of Pr6O 11 The powder was stirred at a constant temperature for 4 hours, then heating was stopped, and the mixture was allowed to cool naturally to room temperature to obtain a mixed suspension.

[0038] 2) Transfer the above mixed suspension into an ultrasonic cell disruptor, set the ultrasonic power to 100W, and sonicate for 10 minutes to remove tiny air bubbles from the mixed suspension.

[0039] 3) Pour the ultrasonically treated mixed suspension into a mold and pre-freeze it in a -25℃ ultra-low temperature freezer for 0.5 h. Then transfer it to a freeze dryer and freeze-dry it at -50℃ for 2 h to obtain CNF-C / Pr6O. 11 Aerogel precursor;

[0040] 4) Prepare an octadecyltrichlorosilane (OTS) / n-hexane solution with a mass concentration of 0.1 wt% as a hydrophobic agent, completely immerse the aerogel precursor in the hydrophobic agent, and modify it at 25°C for 0.5 h.

[0041] 5) Remove the hydrophobically modified aerogel and dry it in a vacuum drying oven at 30℃ for 0.5h to obtain the functional photothermal rare earth (CNF-C / Pr6O). 11 Aerogel.

[0042] Example 2

[0043] 1) Prepare a 0.5 wt% carboxylated nanocellulose (CNF-C) suspension. Weigh 80 g of the carboxylated nanocellulose (CNF-C) suspension and stir continuously in a constant temperature water bath at 400 rpm and 40℃. Slowly add 0.1 g of Pr6O 11 The powder was stirred at a constant temperature for 1 hour, then the heating was stopped and the mixture was allowed to cool naturally to room temperature to obtain a mixed suspension.

[0044] 2) Transfer the above mixed suspension into an ultrasonic cell disruptor, set the ultrasonic power to 500W, and sonicate for 60 minutes to remove tiny air bubbles from the mixed suspension.

[0045] 3) Pour the ultrasonically treated mixed suspension into a mold, pre-freeze it in a -20℃ ultra-low temperature freezer for 1 hour, then transfer it to a freeze dryer and freeze-dry it at -70℃ for 12 hours to obtain CNF-C / Pr6O. 11 Aerogel precursor;

[0046] 4) Prepare a 1 wt% solution of octadecyltrichlorosilane (OTS) / n-hexane as a hydrophobic agent, completely immerse the aerogel precursor in the hydrophobic agent, and modify it at 25°C for 2 hours.

[0047] 5) Remove the hydrophobically modified aerogel and dry it in a vacuum drying oven at 45℃ for 1 hour to obtain the functional photothermal rare earth (CNF-C / Pr6O). 11 Aerogel.

[0048] Example 3

[0049] 1) Prepare a 1 wt% carboxylated nanocellulose (CNF-C) suspension. Weigh 80 g of the carboxylated nanocellulose (CNF-C) suspension and stir continuously in a constant temperature water bath at 400 rpm and 50 °C. Slowly add 0.15 g of Pr6O 11 The powder was stirred at a constant temperature for 2 hours, then the heating was stopped and the mixture was allowed to cool naturally to room temperature to obtain a mixed suspension.

[0050] 2) Transfer the above mixed suspension into an ultrasonic cell disruptor, set the ultrasonic power to 600W, and sonicate for 100 minutes to remove tiny air bubbles from the mixed suspension.

[0051] 3) Pour the ultrasonically treated mixed suspension into a mold and pre-freeze it in a -16℃ ultra-low temperature freezer for 1.5 hours. Then transfer it to a freeze dryer and freeze-dry it at -80℃ for 14 hours to obtain CNF-C / Pr6O. 11 Aerogel precursor;

[0052] 4) Prepare an octadecyltrichlorosilane (OTS) / n-hexane solution with a mass concentration of 1.2 wt% as a hydrophobic agent, completely immerse the aerogel precursor in the hydrophobic agent, and modify it at 35°C for 3 h.

[0053] 5) Remove the hydrophobically modified aerogel and dry it in a vacuum drying oven at 50℃ for 2 hours to obtain the functional photothermal rare earth (CNF-C / Pr6O). 11 Aerogel.

[0054] Example 4

[0055] 1) Prepare a 1.5 wt% carboxylated nanocellulose (CNF-C) suspension. Weigh 80 g of the carboxylated nanocellulose (CNF-C) suspension and stir continuously in a constant temperature water bath at 450 rpm and 60 °C. Slowly add 0.2 g of Pr6O 11 The powder was stirred at a constant temperature for 3 hours, then heating was stopped, and the mixture was allowed to cool naturally to room temperature to obtain a mixed suspension.

[0056] 2) Transfer the above mixed suspension into an ultrasonic cell disruptor, set the ultrasonic power to 600W, and sonicate for 120 minutes to remove tiny air bubbles from the mixed suspension.

[0057] 3) Pour the ultrasonically treated mixed suspension into a mold and pre-freeze it in a -12℃ ultra-low temperature freezer for 2 hours. Then transfer it to a freeze dryer and freeze-dry it at -90℃ for 16 hours to obtain CNF-C / Pr6P. 11 Aerogel precursor;

[0058] 4) Prepare an octadecyltrichlorosilane (OTS) / n-hexane solution with a mass concentration of 1.5 wt% as a hydrophobic agent, completely immerse the aerogel precursor in the hydrophobic agent, and modify it at 50°C for 3 h.

[0059] 5) Remove the hydrophobically modified aerogel and dry it in a vacuum drying oven at 60℃ for 3 hours to obtain the functional photothermal rare earth (CNF-C / Pr6P). 11 Aerogel.

[0060] Example 5

[0061] 1) Prepare a 2wt% carboxylated nanocellulose (CNF-C) suspension. Weigh 80g of the carboxylated nanocellulose (CNF-C) suspension and stir continuously in a 65℃ constant temperature water bath at 500rpm. Slowly add 0.24g of Pr6O. 11 The powder was stirred at a constant temperature for 4 hours, then heating was stopped, and the mixture was allowed to cool naturally to room temperature to obtain a mixed suspension.

[0062] 2) Transfer the above mixed suspension into an ultrasonic cell disruptor, set the ultrasonic power to 700W, and sonicate for 140 minutes to remove tiny air bubbles from the mixed suspension.

[0063] 3) Pour the ultrasonically treated mixed suspension into a mold and pre-freeze it in a -10℃ ultra-low temperature freezer for 2.5 hours. Then transfer it to a freeze dryer and freeze-dry it at -100℃ for 18 hours to obtain CNF-C / Pr6O. 11 Aerogel precursor;

[0064] 4) Prepare an octadecyltrichlorosilane (OTS) / n-hexane solution with a mass concentration of 1.7 wt% as a hydrophobic agent, completely immerse the aerogel precursor in the hydrophobic agent, and modify it at 60°C for 4 h.

[0065] 5) Remove the hydrophobically modified aerogel and dry it in a vacuum drying oven at 65℃ for 4 hours to obtain the functional photothermal rare earth (CNF-C / Pr6O). 11 Aerogel.

[0066] Example 6

[0067] 1) Prepare a 2.5 wt% carboxylated nanocellulose (CNF-C) suspension. Weigh 90 g of the carboxylated nanocellulose (CNF-C) suspension and stir continuously in a constant temperature water bath at 550 rpm and 70 °C. Slowly add 0.28 g of Pr6O 11 The powder was stirred at a constant temperature for 6 hours, then heating was stopped, and the mixture was allowed to cool naturally to room temperature to obtain a mixed suspension.

[0068] 2) Transfer the above mixed suspension into an ultrasonic cell disruptor, set the ultrasonic power to 800W, and sonicate for 160 minutes to remove tiny air bubbles from the mixed suspension.

[0069] 3) Pour the ultrasonically treated mixed suspension into a mold and pre-freeze it in an ultra-low temperature freezer at -8℃ for 2.5 hours. Then transfer it to a freeze dryer and freeze-dry it at -110℃ for 20 hours to obtain CNF-C / Pr6O. 11 Aerogel precursor;

[0070] 4) Prepare an octadecyltrichlorosilane (OTS) / n-hexane solution with a mass concentration of 1.8 wt% as a hydrophobic agent, completely immerse the aerogel precursor in the hydrophobic agent, and modify it at 70°C for 5 h.

[0071] 5) Remove the hydrophobically modified aerogel and dry it in a vacuum drying oven at 70℃ for 5 hours to obtain the functional photothermal rare earth (CNF-C / Pr6O). 11 Aerogel.

[0072] Example 7

[0073] 1) Prepare a 3.0 wt% carboxylated nanocellulose (CNF-C) suspension. Weigh 10 g of the carboxylated nanocellulose (CNF-C) suspension and stir continuously in a constant temperature water bath at 600 rpm and 80℃. Slowly add 0.3 g of Pr6O 11 The powder was stirred at a constant temperature for 8 hours, then heating was stopped, and the mixture was allowed to cool naturally to room temperature to obtain a mixed suspension.

[0074] 2) Transfer the above mixed suspension into an ultrasonic cell disruptor, set the ultrasonic power to 1000W, and sonicate for 180 minutes to remove tiny air bubbles from the mixed suspension.

[0075] 3) Pour the ultrasonically treated mixed suspension into a mold, pre-freeze it in a -5℃ ultra-low temperature freezer for 3 hours, then transfer it to a freeze dryer and freeze-dry it at -120℃ for 24 hours to obtain CNF-C / Pr6O. 11 Aerogel precursor;

[0076] 4) Prepare an octadecyltrichlorosilane (OTS) / n-hexane solution with a mass concentration of 2.0 wt% as a hydrophobic agent, completely immerse the aerogel precursor in the hydrophobic agent, and modify it at 80℃ for 6 h.

[0077] 5) Remove the hydrophobically modified aerogel and dry it in a vacuum drying oven at 80℃ for 6 hours to obtain the functional photothermal rare earth (CNF-C / Pr6O). 11 Aerogel.

[0078] The functional photothermal rare earth aerogel synthesized in Example 2 above, which can be used for the efficient treatment of high-viscosity crude oil wastewater, was characterized and its performance was tested. The results are as follows:

[0079] Figure 2 CNF-C / Pr6O prepared in Example 2 11 X-ray diffraction pattern of aerogel. (e.g.) Figure 2 As shown, the characteristic diffraction peaks of CNF-C are mainly located at 22.6° and 34.7°, corresponding to the (002) and (004) crystal planes of CNF-C, respectively. This result is consistent with the CNF-C standard card JCPDS#030223. Pr6O 11 The XRD pattern of the sample exhibits typical oxygen-deficient fluorite crystal structure characteristics. Strong diffraction peaks at 2θ = 28.5°, 33.1°, 47.5°, and 56.3° correspond to the (111), (200), (220), and (311) crystal planes of the fluorite structure, respectively. Simultaneously, a series of weaker superlattice diffraction peaks are observed at 2θ = 19.5°, 30.5°, and 41.2°, which are characteristic signals generated by the periodic ordered arrangement of oxygen vacancies in the lattice. Compared to standard PrO2, all main diffraction peaks show a slight shift towards smaller angles, indicating that the oxygen vacancies are due to the oxygen vacancies in the superlattice. 3+ The increase in lattice parameters due to the increased ion ratio confirms that Pr6O 11 Formation of non-stoichiometric compounds. For CNF-C / Pr6O 11 XRD pattern analysis of the aerogel revealed that the composite material successfully combined the structural features of both components. The pattern exhibited a broad diffuse diffraction pattern at approximately 22.6°, a typical characteristic of the amorphous structure of carboxylated nanocellulose (CNF-C), stemming from its amorphous carbon skeleton and nanofiber network. Simultaneously, Pr6O was clearly observed in the pattern. 11 A series of sharp diffraction peaks are observed in the crystal, with the most prominent main peak corresponding to the (111), (200), (220), and (311) crystal planes of the fluorite structure. Characteristic superlattice diffraction peaks caused by the ordered arrangement of oxygen vacancies are also observed at lower angles. Pr6O 11The crystalline peaks of Pr6O coexist harmoniously with the amorphous dispersions of CNF-C, and no diffraction peaks of other impurities are observed, confirming that Pr6O 11 Nanoparticles have been successfully loaded into CNF-C grids, maintaining their intrinsic crystal structure and photothermal activity, forming a good physical and chemical composite.

[0080] Figure 3 CNF-C / Pr6O prepared in Example 2 11 Fourier transform infrared (FT-IR) spectrum of the aerogel. The FT-IR spectrum of CNF-C exhibits typical characteristic absorption peaks of cellulose: 3340 cm⁻¹. -1 The broad peak at 2900 cm⁻¹ belongs to the OH stretching vibration. -1 The weak peak at the wavenumber corresponds to the CH stretching vibration, while the one at 1600 cm⁻¹ represents the CH stretching vibration. -1 and 1410cm -1 The absorption bands at these locations correspond to the asymmetric and symmetric stretching vibrations of the carboxyl group (-COO-), respectively. Pr6O 11 The atlas is at 620cm -1 and 510cm -1 The vicinity shows broad vibrational peaks characteristic of Pr-O bonds. In CNF-C / Pr6O... 11 In the composite spectra of the aerogel, the following key changes can be observed: compared with pure CNF-C, the asymmetric stretching vibration peak of the carboxyl group (1600 cm⁻¹) is significantly different. -1 The peak underwent a significant red shift and its shape changed, indicating that the carboxylate ion (-COO-) of CNF-C reacts with Pr6O. 11 Significant coordination interactions occurred between Pr ions on the surface, forming stable ionic or coordinate bonds. Furthermore, the slight shift and broadening of the OH stretching vibration peak further corroborates the possibility of hydrogen bonding between the hydroxyl groups on the cellulose chains and the rare earth oxide surface. These molecular-level interactions are the key foundation for constructing stable composite aerogel structures, achieving efficient stress transfer, and demonstrating excellent photothermal properties.

[0081] Figure 4 CNF-C / Pr6O prepared in Example 2 11 Electron micrographs of the aerogel. CNF-C exhibits a dense, sheet-like or fibrous bundle-like aggregate morphology, formed by the tight stacking of disordered layered structures with diameters of approximately 100–120 μm. Its nanoscale fibrous structure is tightly aggregated due to strong hydrogen bonding. Pr6O 11 The powder exhibits as micron-sized, irregularly shaped, blocky particles with smooth surfaces, significant rigidity, and a tendency for close packing. This contrasts sharply with CNF-C / Pr6O. 11The composite aerogel exhibits a typical three-dimensional, continuous, porous network structure; at high magnification, CNF-C is clearly visible as fully dispersed and reconstructed into a fine nanofiber framework, while Pr6O... 11 The particles, acting as functional nodes, are uniformly embedded or encapsulated within the cellulose network, together forming a stable composite with hierarchical porosity. This dramatic morphological transformation not only demonstrates the successful nanofiber dispersion and three-dimensional network self-assembly of CNF-C during the preparation process, but also indicates the effectiveness of Pr6O. 11 The particles exhibit good compatibility and interaction with the CNF-C matrix, thus providing an ideal structural basis for photothermal conversion and oil-water separation.

[0082] Figure 5 CNF-C / Pr6O prepared in Example 2 11 Images showing the wetting properties of the aerogel before and after hydrophobicity. From Figure 5 As can be seen in a, water droplets can be stably retained in a spherical shape in the hydrophobic CNF-C / Pr6O 11 High-viscosity crude oil can completely penetrate CNF-C / Pr6O onto the surface and cross-section of the aerogel. 11 The surface and cross-section of the aerogel indicate the presence of hydrophobic CNF-C / Pr6O 11 Aerogels are hydrophobic both on their surface and inside. Figure 5 As shown in b, water droplets can completely penetrate into the non-hydrophobic CNF-C / Pr6O 11 The surface and cross-section of the aerogel indicate the presence of non-hydrophobic CNF-C / Pr6O 11 Aerogels possess hydrophilicity both on their surface and within their interior. The above results indicate that after hydrophobic modification, CNF-C / Pr6O... 11 Aerogels have excellent hydrophobicity.

[0083] Figure 6 CNF-C / Pr6O prepared in Example 2 11 Adsorption performance of aerogels on high-viscosity crude oil under different light intensities, and the crude oil adsorption process. From Figure 6 It can be observed that under no-light conditions, the adsorption process is slow and the final adsorption capacity is limited due to the high viscosity of crude oil. As the light intensity increases (from 0.5 kW·m²), the adsorption capacity increases further. -2 Increased to 2.0 kW·m -2 The adsorption rate and saturated adsorption capacity both showed a significant stepwise increase. This phenomenon is attributed to Pr6O in the aerogel. 11The components efficiently convert light energy into heat energy under illumination, locally heating the crude oil in the contact area, thereby effectively reducing its viscosity and significantly improving the flowability and permeability of the crude oil in the aerogel porous network. This result directly proves the effectiveness of CNF-C / Pr6O. 11 Aerogels possess excellent photothermal conversion capabilities and demonstrate their practical potential for efficient and rapid separation of high-viscosity crude oil while reducing energy consumption. However, under natural conditions, the maximum intensity of sunlight is only 1 kW·m. -2 Therefore, in this embodiment, a light intensity of 1.0 kW·m is selected. -2 Adsorption of high-viscosity crude oil. Figure 6 b shows the illumination intensity at 1.0 kW·m -2 Under these conditions, CNF-C / Pr6O 11 The process of aerogel adsorption of high-viscosity crude oil. As shown in the process diagram, high-viscosity crude oil can completely penetrate CNF-C / Pr6O within 5 minutes. 11 In aerogels, this indicates CNF-C / Pr6O 11 Aerogels have a good pore structure and hydrophobic / philic properties, and exhibit good adsorption properties for oily substances.

[0084] Under a certain solar radiation intensity, the CNF-C / Pr6O prepared in Examples 1-7 were subjected to... 11 The adsorption performance of aerogels on high-viscosity crude oil was compared. As shown in Table 1, the aerogel material prepared in Example 2 exhibited the best adsorption performance. This result is attributed to the optimized combination of preparation parameters in Example 2, which ensured the formation of an ideal three-dimensional porous network structure and high porosity, thereby achieving the most efficient adsorption and permeation of high-viscosity crude oil under photothermal conditions. Therefore, Example 2 was determined to be the optimal preparation scheme for this functional photothermal rare earth aerogel.

[0085] Figure 7 CNF-C / Pr6O prepared in Example 2 11 The process of aerogel adsorbing high-viscosity crude oil and then extruding and regenerating it to restore elastic deformation, and the height comparison before and after extrusion. Figure 7 a indicates that CNF-C / Pr6O after adsorption of high-viscosity crude oil 11 Aerogels can release adsorbed high-viscosity crude oil through mechanical extrusion, and the CNF-C / Pr6O after mechanical extrusion... 11 Aerogels can recover their elastic deformation in a very short time. Figure 7 b records the CNF-C / Pr6O after adsorption of high-viscosity crude oil. 11 The height recovery of aerogel after mechanical extrusion. From Figure 7As can be observed in b, after mechanical extrusion, CNF-C / Pr6O 11 The height of aerogel recovery is related to mechanical extrusion CNF-C / Pr6O 11 The heights of the aerogels were generally consistent. These results indicate that CNF-C / Pr6O 11 Aerogels have excellent elasticity and mechanical properties, and can be regenerated and recycled through simple mechanical extrusion.

[0086] Figure 8 This demonstrates the CNF-C / Pr6O prepared in Example 2 of the present invention. 11 Adsorption-desorption cycle performance of aerogels on high-viscosity crude oil. Figure 8 This indicates that after 1 solar radiation intensity (1 kW·m) -2 After irradiation, CNF-C / Pr6O 11 During 20 adsorption-desorption cycles of high-viscosity crude oil, the adsorption capacity of the aerogel remained within 15%, indicating that CNF-C / Pr6P... 11 Aerogels have good recyclability.

[0087] The functional photothermal rare earth aerogel (CNF-C / Pr6P) of the present invention 11 This invention is applied to the treatment of high-viscosity crude oil wastewater. The scope of protection of this invention is not limited to the above embodiments; all technical solutions falling within the scope of this invention's concept are protected.

[0088] Table 1. Different aerogels under light intensity of 1 kW·m -2 Adsorption performance of high viscosity crude oil under certain conditions

[0089]

Claims

1. A method for preparing a functional photothermal rare earth aerogel that can be used for the efficient treatment of high-viscosity crude oil wastewater, characterized in that: 1) First, a carboxylated nanocellulose (CNF-C) suspension was prepared, and then rare earth Pr6O was added under isothermal hydrothermal conditions. 11 The mixture was added to CNF-C solution to obtain a mixed suspension; after cooling to room temperature, the tiny air bubbles in the mixed suspension were removed by ultrasonic disruption. 2) First, pre-freeze the mixed suspension obtained in step 1), and then freeze-dry it to obtain CNF-C / Pr6O. 11 Aerogel precursor. 3) Prepare a hydrophobic agent and apply the CNF-C / Pr6O obtained in step 2) to the solution impregnation method. 11 Hydrophobic modification of the aerogel precursor followed by vacuum drying yields a functional photothermal rare earth (CNF-C / Pr6O3) ​​that can efficiently treat high-viscosity crude oil wastewater. 11 Aerogel.

2. The preparation method of the functional photothermal rare earth aerogel that can be used for efficient treatment of high-viscosity crude oil wastewater according to claim 1, characterized in that: The carboxylated nanocellulose (CNF-C) suspension has a mass concentration of 0.1wt% to 3.0wt%, and the mass of the added material is 10 to 100g.

3. The preparation method of the functional photothermal rare earth aerogel that can be used for efficient treatment of high-viscosity crude oil wastewater according to claim 1, characterized in that: The rare earth element is Pr6O. 11 The amount added is 0.01 to 0.30 g.

4. The preparation method of the functional photothermal rare earth aerogel that can be used for efficient treatment of high-viscosity crude oil wastewater according to claim 1, characterized in that: The stirring temperature of the mixed suspension is 40-80℃, the stirring time is 1-8h, and the rotation speed of the magnetic stirring rotor is 100-600 rpm / min; the ultrasonic power of the ultrasonic cell disruptor is 100-1000W, and the ultrasonic time is 10-180min.

5. The preparation method of the functional photothermal rare earth aerogel that can be used for efficient treatment of high-viscosity crude oil wastewater according to claim 1, characterized in that: The pre-freezing treatment uses an ultra-low temperature freezer to pre-freeze the mixed suspension at a temperature of -25 to -5°C for 0.5 to 3.0 hours. The freeze-drying treatment uses a freeze dryer to process the pre-freezed mixed suspension at a temperature of -120 to -50°C for 2 to 24 hours.

6. The preparation method of the functional photothermal rare earth aerogel that can be used for efficient treatment of high-viscosity crude oil wastewater according to claim 1, characterized in that: The solute of the hydrophobic agent is one of a silane coupling agent or an isocyanate; the solvent of the hydrophobic agent is one of a ketone, ester, ether, benzene, or aromatic hydrocarbon.

7. The preparation method of the functional photothermal rare earth aerogel that can be used for efficient treatment of high-viscosity crude oil wastewater according to claim 1, characterized in that: The mass concentration of the hydrophobic agent is 0.1–2.0 wt%; the hydrophobic modification temperature is set to 25–80 °C and the hydrophobic modification time is 0.5–6.0 h; the hydrophobic modified aerogel material is dried in a vacuum drying oven at a temperature of 30–80 °C for 0.5–6.0 h.

8. A functional photothermal rare earth aerogel that can be used for the efficient treatment of high-viscosity crude oil wastewater, characterized in that... The aerogel is synthesized according to any one of claims 1-7. It has a porous structure on its surface and interior, a water contact angle greater than 150°, an oil contact angle of 0°, and exhibits superhydrophobicity.

9. The functional photothermal rare earth aerogel of claim 8, characterized in that: Under photothermal conditions, it can be used for the adsorption and separation of high-viscosity crude oil wastewater.

Images