Silicon-based adsorbent for oil gas recovery and preparation method thereof

Abstract

The invention belongs to the technical field of oil gas recovery, and provides a silicon-based adsorbent for oil gas recovery and a preparation method thereof. The method comprises the following steps: reacting calix [4] arene with 4-bromomethylpyridine and chloromethyl (diphenyl) phosphine to obtain phosphino calix [4] arene, and reacting the phosphino calix [4] arene with 3-chloropropyltriethoxysilane and zinc chloride to obtain metal coordination calix [4] arene; secondly, mixing choline chloride, glycerol, 1-butyl-3-methylimidazole bis (trifluoromethanesulfonyl) imide salt, glycidyl acrylate and a nickel ion-containing solution, and introducing N, N-methylene bisacrylamide and azodiisobutyronitrile to react, so as to obtain an ionic liquid mixed solution; the porous silicon material is soaked in a mixed solution of a metal coordination calix [4] arene solution and an ionic liquid, and the prepared multifunctional composite silicon-based adsorbent is used for solving the problem that a traditional adsorbent is prone to failure under high temperature or complex working conditions.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil and gas recovery, and relates to a silicon-based adsorbent for oil and gas recovery and a preparation method thereof. Background Art

[0002] As a complex hydrocarbon mixture, petroleum often causes resource waste and environmental pollution problems due to the escape of volatile oil and gas during storage, transportation, and loading and unloading. These volatile oil and gas are mainly composed of various organic compounds such as alkanes and aromatics. Components such as benzene and xylene not only have high volatility but also cause serious harm to human health and the atmospheric environment. In addition, the loss of volatile oil and gas will also reduce the quality of oil products, resulting in the final products not meeting the standards. Therefore, how to efficiently recover volatile oil and gas, achieve the recycling of resources, and reduce environmental pollution has become the research focus and technical problem in the petrochemical industry.

[0003] At present, oil and gas recovery technologies mainly include absorption method, condensation method, membrane separation method, and adsorption method, etc. Among them, the absorption method uses lean oil such as diesel as an absorbent to transfer the oil and gas components from the gas phase to the liquid phase through physical absorption. Although this method has a simple process, due to the limited solubility of the absorbent in oil and gas components, the overall recovery efficiency is low and it is difficult to meet the industrial demand. The condensation method uses refrigeration technology to directly condense the oil and gas components from the gas phase into the liquid phase for recovery. Although its effect is good, the equipment investment cost is high, the operation energy consumption is large, and the payback period is long, which limits its wide application. The membrane separation method uses the selective permeation characteristics of polymer membranes to separate the target components from the oil and gas mixture. Although this method has a certain separation effect, the membrane material is sensitive to operating conditions, and its performance is prone to decay during long-term operation, and the system operation stability needs to be further improved. In contrast, the adsorption method has become a widely used technology in the current oil and gas recovery field due to its advantages such as simple operation, small equipment investment, and high recovery efficiency. The adsorption method selectively adsorbs the volatile oil and gas components on the surface of the adsorbent, enriches the hydrocarbon compounds in the oil and gas on the surface of the adsorbent, and then recovers the oil and gas through the desorption process to achieve the recycling of resources. Commonly used adsorbents include activated carbon, silica gel, activated fibers, etc. Activated carbon is widely used due to its high specific surface area and good adsorption performance, but it is prone to failure under high temperature or complex working conditions, and its selectivity for different components in oil and gas is weak.

[0004] To solve the above problems, developing new adsorption materials that can balance high efficiency, safety, and recyclability has become an important research direction in the oil and gas recovery field. As a porous material composed of silicon elements, silicon-based adsorbents exhibit great application potential in adsorption technology due to their unique physical and chemical properties. Silicon-based materials have a highly adjustable pore structure, excellent thermal stability, high mechanical strength, and rich surface modification capabilities. Based on this, developing a silicon-based adsorbent for oil and gas recovery has important research significance and practical value. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a silicon-based adsorbent for oil and gas recovery and its preparation method. By loading functionalized metal-coordinated calix[4]arene and ionic liquid onto a porous silicon material, a multifunctional composite adsorbent is formed. Utilizing metal coordination chemistry, the multiple interactions of ionic liquids, and the high specific surface area of silicon-based materials, efficient selective adsorption of various components in oil and gas (such as alkanes, aromatics, unsaturated hydrocarbons, and sulfur- and nitrogen-containing compounds) is achieved, thus meeting the needs of actual production.

[0006] To achieve this purpose, the present invention adopts the following technical solutions: In the first aspect, the present invention provides a preparation method of a silicon-based adsorbent for oil and gas recovery, and the preparation method includes: A1. Mix tetraethoxysilane with an ethanol aqueous solution evenly, then add a hydrochloric acid solution and stir. After stirring evenly, add CTAB, stir and mix, then transfer to a water bath condition, adjust the temperature to the third temperature and let it stand. After drying the product, soak it in a hydrochloric acid-ethanol solution, and after the soaking is completed, wash and dry to obtain a porous silicon material; S1. Under a nitrogen atmosphere, disperse calix[4]arene in anhydrous N,N-dimethylformamide. After dispersing evenly, add potassium carbonate, then add a 4-bromomethylpyridine solution, adjust the temperature to the first temperature and reflux for reaction. After the reaction is completed, extract and dry to obtain heterocyclic calix[4]arene. Then disperse the heterocyclic calix[4]arene in anhydrous N,N-dimethylformamide, add potassium carbonate after dispersing evenly, then add a chloromethyl(diphenyl)phosphine solution, adjust the temperature to the second temperature and stir for reaction. After the reaction is completed, extract and dry to obtain phosphine calix[4]arene; S2. Disperse phosphine calix[4]arene in anhydrous toluene, add triethylamine and stir evenly, then add 3-chloropropyltriethoxysilane, adjust the temperature to the third temperature and stir for reaction. After the reaction is completed, extract and dry to obtain a crude product. Then disperse the crude product in anhydrous dimethyl sulfoxide, add zinc chloride and stir for reaction to obtain metal-coordinated calix[4]arene; S3. After mixing choline chloride and glycerol, adjust the temperature to the fourth temperature under water bath conditions, keep stirring, then transfer to a nitrogen purge condition, adjust the temperature to the fifth temperature and maintain it to obtain a mother liquor. Add 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide to the mother liquor, mix well, then add glycidyl acrylate, adjust the temperature to the sixth temperature and maintain nitrogen purge to obtain an intermediate mixture. Add a nickel nitrate dispersion to the intermediate mixture, adjust the temperature to the fifth temperature and stir to obtain an intermediate mixture containing Ni 2+ . Disperse N,N'-methylenebisacrylamide and azobisisobutyronitrile in absolute ethanol and then add them to the intermediate mixture containing Ni 2+ to obtain an ionic liquid mixture; S4. Immerse the porous silicon material in a solution of metal-coordinated calix[4]arene, adjust the temperature to the fourth temperature, evacuate and maintain, then return to atmospheric pressure and cycle. After the immersion is completed, take it out and dry it, then immerse it in the ionic liquid mixture. Adjust the temperature to the fifth temperature and maintain it, then adjust the temperature to the fourth temperature and maintain it. After the immersion is completed, take it out and dry it to obtain a silicon-based adsorbent for oil and gas recovery.

[0007] Calix[4]arene is composed of four phenolic rings connected by methylene bridges, forming a cyclic structure with external hydroxyl groups. The hydroxyl groups of calix[4]arene can react with bases to form phenolates, which are more prone to nucleophilic substitution reactions with electrophiles. Under anhydrous conditions, potassium carbonate, as a weak base, undergoes an acid-base reaction with the phenolic hydroxyl groups outside calix[4]arene to form phenolates. The resulting phenolate is a strong nucleophile with its negative charge concentrated on the oxygen atom, capable of reacting efficiently with electrophiles. Moreover, potassium carbonate also acts as a dehydrating agent to ensure that the system maintains an anhydrous environment, thereby improving the reaction efficiency. The 4-bromomethylpyridine molecule contains a pyridine ring and a bromomethyl group. The bromine atom has a strong electron-withdrawing effect, causing the adjacent methyl carbon to carry a positive charge, acting as a reactive electrophilic center. The pyridine ring is a conjugated aromatic compound with aromaticity. Its π-electron cloud is distributed above and below the plane of the pyridine ring, showing a relatively high electron density. The modification of calix[4]arene makes it carry multiple pyridine groups on its periphery. These aromatic groups can undergo π-π interactions with other aromatic molecules through the overlap of π electrons. The aromatic groups introduced by the pyridine ring can have a π-π stacking effect with the aromatic compounds in the oil and gas molecules. Due to the relatively high electronegativity of the nitrogen atom in the pyridine ring, the π-electron cloud on its ring will shift slightly towards the nitrogen atom, so pyridine exhibits certain electron acceptor properties. In contrast, the aromatic compounds in the oil and gas usually show electron donor properties, which intensifies the strength of the π-π interaction. The aromaticity of the pyridine ring matches that of the aromatic compounds in the oil and gas, and stable non-covalent bonding is formed between molecules through π-π stacking. The van der Waals force between molecules and the electrostatic interaction of π electrons further enhance the binding between the adsorbent and the oil and gas molecules. The pyridine groups outside the heterocyclic calix[4]arene provide multiple sites rich in π electrons, forming stable π-π interactions with the aromatic compounds in the oil and gas. This interaction improves the selectivity and adsorption capacity of the adsorbent for aromatic compounds such as benzene, toluene, and xylene. At the same time, the π-π interaction is a relatively directional intermolecular interaction. Combining with the rigid framework structure of calix[4]arene, it makes the capture ability of the adsorbent for aromatic molecules more efficient and stable.

[0008] The nitrogen atom on the pyridine ring has a lone pair of electrons and a relatively high electronegativity, which makes the pyridine ring exhibit polar properties. By introducing pyridine groups, heterocyclic calix[4]arenes have multiple polar sites on their periphery and can interact with polar molecules. Oil and gas often contain polar compounds such as alcohols, ketones, ethers or carbonyl compounds, and these molecules can interact with pyridine groups through their polar groups. Due to the presence of the lone pair of electrons, the nitrogen atom of the pyridine ring can act as a hydrogen bond acceptor and form hydrogen bonds with hydrogen bond donors in polar molecules. The formation of hydrogen bonds makes the intermolecular binding more stable and further enhances the ability of the adsorbent to capture polar molecules; the lone pair of electrons of the nitrogen atom in the pyridine ring can act as a Lewis base and coordinate with the Lewis acid center in oil and gas molecules, and the Lewis acid-base interaction can enhance the binding between the adsorbent and polar molecules. Due to the presence of the lone pair of electrons, the nitrogen atom of the pyridine ring shows weak basicity and can undergo acid-base interactions with acidic molecules. Oil and gas may contain acidic components such as carboxylic acid compounds, sulfate esters or other organic molecules containing acidic groups. As a Lewis base, the pyridine group binds to protons or acidic sites in acidic molecules to form stable acid-base complexes. The strength of this acid-base interaction is higher than that of hydrogen bonds or van der Waals forces. Therefore, heterocyclic calix[4]arenes can efficiently capture acidic pollutants in oil and gas, and the strength of the acid-base interaction makes the capture of acidic molecules by the adsorbent more stable and efficient. By introducing pyridine groups, heterocyclic calix[4]arenes achieve multiple functionalizations. The pyridine groups on their periphery provide the adsorbent with the ability to adsorb different chemical components in oil and gas through π-π interactions, polar sites and basic properties. π-π interactions capture aromatic compounds, polar sites provide selectivity for polar molecules, and basic properties enhance the ability to capture acidic molecules, enhancing the molecular recognition ability of the adsorbent, enabling it to efficiently capture complex components in oil and gas, while improving the adsorption efficiency and selectivity.

[0009] Chloromethyl(diphenyl)phosphine is a bifunctional reagent. The chloromethyl group, as an electrophilic group, can undergo nucleophilic substitution reactions with nucleophiles. Due to the lone pair of electrons, the phosphine group exhibits strong Lewis basicity, and the lone pair of electrons can coordinate with metal ion centers to form stable phosphine coordination compounds. The phosphine group connects two benzene rings, showing strong aromaticity, enabling it to interact with non-polar compounds (such as hydrocarbons) in oil and gas molecules. The rigid skeleton and multiple modifying groups (such as multiple phosphine groups) of calix[4]arene molecules allow them to form multidentate coordination structures with metal ions. Each phosphine group can coordinate with a metal ion separately to form a polymetallic coordination network, or multiple phosphine groups can coordinate with the same metal ion simultaneously to form a stable chelate structure. The coordinated metal-phosphine complex has higher thermodynamic and kinetic stability and can maintain its function in a complex adsorption environment. The organophilicity of the phosphine group mainly stems from the aromatic groups in its structure, which can bind to non-polar components (such as alkanes and aromatics) in oil and gas molecules through van der Waals forces or π-π interactions. The calix[4]arene is peripherally equipped with multiple phosphine groups, effectively enhancing the affinity of the adsorbent for non-polar molecules. The functionalization by introducing phosphine groups through chloromethyl(diphenyl)phosphine endows heterocyclic calix[4]arene with higher metal coordination ability and adsorption ability for non-polar oil and gas molecules. The lone pair of electrons of the phosphine group endows the material with the ability to bind to metal ions to form stable coordination compounds, while its aromatic groups enhance the affinity of the adsorbent for non-polar components.

[0010] Phosphine calix[4]arene has peripheral phosphine groups and phenolic hydroxyl groups. The 3-chloropropyltriethoxysilane molecule contains an electrophilic chloromethyl group and a triethoxysilyl group. The chloromethyl group can undergo nucleophilic substitution reactions with nucleophiles. The phenolic hydroxyl groups in phosphine calix[4]arene are partially deprotonated to form phenoxide forms under the action of weak base triethylamine, making it more nucleophilic. The crude product is a siloxane-modified product of phosphine calix[4]arene, which has phosphine and siloxane groups on its periphery. ZnCl2 is a classic Lewis acid with strong electron acceptor properties and can coordinate with the phosphine group to form a stable phosphine coordination compound. The zinc ion becomes the active center in the material through coordination. Zn 2+ As a strong Lewis acid, it can adsorb Lewis basic molecules in oil and gas, effectively enhancing the selectivity of the adsorbent for polar molecules. The combined action of the rigid skeleton of calix[4]arene and the peripheral functional groups (phosphine-metal coordination centers) endows the adsorbent with high adsorption ability for oil and gas molecules. The aromaticity of the phosphine group enhances the adsorption of non-polar components (such as alkanes and aromatic hydrocarbons). Zn 2+ The Lewis acidity of the metal center provides additional adsorption sites and can efficiently capture polar compounds.

[0011] Choline chloride is mixed with glycerol under heating conditions. The chloride ions of choline chloride and the hydroxyl groups in glycerol molecules form a stable hydrogen bond network through strong hydrogen bond interactions. The formation of the hydrogen bond network not only reduces the melting point of the system, making it liquid at room temperature, but also provides a highly organized microenvironment for the molecular adsorption of oil and gas molecules. This hydrogen bond network can effectively capture polar molecules in oil and gas, such as carbonyl-containing compounds. Among them, chloride ions, as Lewis bases, can have electrostatic interactions with these polar groups. In addition, the hydrogen bond network can also form weak intermolecular interactions with non-polar molecules (such as alkanes and aromatics), for example, stabilizing their adsorption through van der Waals forces or induced dipole interactions. This dual effect enables the adsorbent to exhibit high selectivity and adsorption capacity when adsorbing oil and gas molecules. To further enhance the capture ability of the adsorbent for complex components in oil and gas, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide is introduced in the present invention. The addition of this ionic liquid endows the adsorbent with richer chemical functionality and molecular recognition ability. Due to the aromaticity of its imidazole ring, the imidazole cation provides a high-density π electron cloud, which can bind to aromatic hydrocarbon molecules in oil and gas through π-π stacking interactions, not only increasing the adsorption selectivity for aromatic hydrocarbon molecules but also enhancing the capture ability of the adsorbent for aromatic hydrocarbons. At the same time, the bis(trifluoromethylsulfonyl)imide anion in the ionic liquid, as a weak coordinating anion, exhibits Lewis basicity and has electrostatic interactions with polar molecules, further improving the selective adsorption ability of the adsorbent for these polar components and providing a more diverse molecular binding mechanism for the adsorbent, enabling it to adapt to the complexity of oil and gas components.

[0012] On this basis, glycidyl acrylate is also added in the present invention to further improve the capture ability of the adsorbent for specific components in oil and gas. The epoxy group in the glycidyl acrylate molecule, due to its high electrophilicity, can undergo chemical reactions with nucleophilic groups in oil and gas molecules, such as sulfur atoms or nitrogen atoms with lone pairs of electrons. This chemical binding further enhances the selectivity of the adsorbent for sulfur- and nitrogen-containing compounds. In addition, due to the electron-withdrawing effect of the acrylate group in the glycidyl acrylate molecule, it can interact with olefin molecules in oil and gas through π electron stacking. This mechanism of action improves the adsorption ability of the adsorbent for unsaturated hydrocarbon compounds. The bifunctional structure (epoxy group and acrylate group) of glycidyl acrylate makes it exhibit multifunctionality during the adsorption process and can capture target molecules with different characteristics simultaneously. Nickel ions, as classic Lewis acids, can have coordination interactions with Lewis basic groups in oil and gas molecules (such as sulfur atoms S in sulfur-containing compounds and nitrogen atoms N in nitrogen-containing compounds). The coordination interaction is essentially the formation of a stable coordination bond by nickel ions accepting the lone pair of electrons in the target molecule. This effect significantly enhances the capture ability of the adsorbent for sulfur- and nitrogen-containing compounds. For example, Ni 2+It can coordinate with the sulfur atom in thiophene or the nitrogen atom in pyridine molecule to form a stable complex, thereby selectively adsorbing these heteroatom compounds. Meanwhile, in order to improve the mechanical strength and chemical stability of the adsorbent, the present invention designs a three-dimensional crosslinked network based on free radical polymerization. During this process, N,N-methylenebisacrylamide and azobisisobutyronitrile are added as crosslinking agent and free radical initiator respectively. Under heating conditions, azobisisobutyronitrile decomposes to generate free radicals, initiating the polymerization reaction of glycidyl acrylate and N,N-methylenebisacrylamide, and generating a three-dimensional crosslinked network structure with multifunctional sites. As a crosslinking agent, N,N-methylenebisacrylamide undergoes a crosslinking reaction with acrylate monomers through its bisacrylamide groups, forming a highly crosslinked polymer network. This three-dimensional crosslinked structure enhances the mechanical strength and solvent resistance of the adsorbent, enabling it to work stably for a long time in a complex oil and gas adsorption environment.

[0013] Through the synergistic effect of the adsorbent with the mixture of metal-coordinated calix[4]arene and ionic liquid, the adsorption capacity for diverse components in oil and gas is enhanced. Due to its unique molecular structure and chemical properties, calix[4]arene provides the core function of molecular recognition. Its rigid aromatic skeleton has high structural stability, and the peripheral aromatic rings are rich in π electron clouds, which can form stable complexes with aromatic molecules in oil and gas through π-π stacking interactions. This not only enhances the adsorption capacity for aromatic hydrocarbon molecules but also shows strong selectivity. In addition, the hydrophobic inner cavity of calix[4]arene interacts with weakly polar molecules (such as alkanes) through van der Waals forces, making it an ideal functional group for capturing non-polar or weakly polar molecules, and enabling it to efficiently and selectively adsorb oil and gas components with specific structures. Meanwhile, both the π-π stacking and hydrophobic interactions between calix[4]arene and aromatic molecules are non-covalent interactions with relatively low binding energy, and these interactions can be disrupted by moderately raising the temperature or evacuating the vacuum, thus realizing the regeneration of the adsorbent. Moreover, the aromatic skeleton of calix[4]arene has strong rigidity and high chemical stability, is not easily degraded, and can maintain its molecular recognition function for a long time, which lays a stable and reliable foundation for the long-term repeated use of the adsorbent.

[0014] The ionic liquid mixture synergistic with calix[4]arene further expands the adaptability of the adsorbent to complex oil and gas components. The ionic liquid mixture consists of components such as 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, choline chloride, and glycerol. Its low vapor pressure and diverse intermolecular interaction modes enable it to efficiently capture various types of oil and gas molecules. The imidazole cation in the ionic liquid, due to its aromatic π electron cloud, binds to aromatic molecules and unsaturated molecules in the oil and gas through π-π stacking, significantly enhancing the selective adsorption capacity for these components. The bis(trifluoromethylsulfonyl)imide anion, as a weakly coordinating anion, can bind to sulfur or nitrogen atoms in heteroatom-containing compounds through electrostatic interaction, further improving the adsorption performance of the adsorbent for sulfur- and nitrogen-containing compounds. In addition, the hydrogen bond donors in the ionic liquid mixture can form hydrogen bond complexes with polar end groups in oil and gas molecules, significantly enhancing the adsorption capacity for polar molecules. The versatility of this dissolution and complexation makes the ionic liquid mixture exhibit extremely high adaptability, capable of capturing various chemical components in oil and gas from non-polar to polar, from aromatic molecules to heteroatom-containing molecules. The ionic liquid mixture exhibits excellent reversibility and stability during the adsorption and desorption processes. The hydrogen bond interaction, electrostatic interaction, and π-π stacking interaction between oil and gas molecules and the ionic liquid mixture are all non-covalent interactions. These interactions can be disrupted by moderately increasing the temperature and evacuating the vacuum during the desorption process, thereby achieving the desorption of molecules and the regeneration of the adsorbent. In addition, the ionic liquid mixture has a low vapor pressure and will not volatilize or be lost during the desorption process, ensuring the low-loss property and long-cycle use performance of the adsorbent. Its core component, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, has extremely high thermal stability and is not easily decomposed or denatured. Through the synergistic effect of the molecular recognition ability of calix[4]arene and the dissolution / complexation of the ionic liquid mixture, the adsorbent shows extremely high versatility and selectivity in the adsorption of oil and gas components. Calix[4]arene mainly captures aromatic molecules and weakly polar molecules through π-π stacking and molecular recognition, while the ionic liquid mixture effectively adsorbs polar molecules, unsaturated molecules, and heteroatom-containing molecules through hydrogen bond complexation and electrostatic interaction. The combination of the two not only enables the adsorbent to adapt to the complex chemical components in oil and gas but also maintains excellent stability and low loss during the adsorption and desorption cycles. The structural integrity and adsorption performance of the adsorbent are basically not affected during multiple cycles of use, extending its service life.

[0015] As a preferred technical solution of the present invention, in step A1, the volume ratio of the tetraethoxysilane, the ethanol aqueous solution, and the hydrochloric acid solution is 4:20:1.

[0016] In some alternative examples, the volume ratio of absolute ethanol to deionized water in the ethanol aqueous solution is 4:1.

[0017] In some alternative examples, the concentration of the hydrochloric acid solution is 0.1 M.

[0018] In some alternative examples, the volume-to-mass ratio of the tetraethoxysilane to CTAB is 20 mL: 3 g.

[0019] In some alternative examples, the standing time at the third temperature is 12 - 14 h. For example, it can be 12.0 h, 12.2 h, 12.4 h, 12.6 h, 12.8 h, 13.0 h, 13.2 h, 13.4 h, 13.6 h, 13.8 h, or 14.0 h. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0020] In some alternative examples, in the hydrochloric acid - ethanol solution, the volume ratio of absolute ethanol to hydrochloric acid is 10:1.

[0021] In some alternative examples, the soaking time is 6 - 8 h. For example, it can be 6.0 h, 6.2 h, 6.4 h, 6.6 h, 6.8 h, 7.0 h, 7.2 h, 7.4 h, 7.6 h, 7.8 h, or 8.0 h. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0022] As a preferred technical solution of the present invention, in step S1, the mass-to-volume ratio of the calix[4]arene to anhydrous N,N-dimethylformamide is 1 g: 50 mL.

[0023] In some alternative examples, the mass ratio of the calix[4]arene to potassium carbonate is 4:3.

[0024] In some alternative examples, the mass-to-volume ratio of the calix[4]arene to the 4-bromomethylpyridine solution is 2 g: 25 mL.

[0025] In some alternative examples, the mass fraction of the 4-bromomethylpyridine solution is 4.5 wt.%, and the solvent is anhydrous N,N-dimethylformamide.

[0026] In some alternative examples, the first temperature is 100 - 110 °C. For example, it can be 100.0 °C, 101.0 °C, 102.0 °C, 103.0 °C, 104.0 °C, 105.0 °C, 106.0 °C, 107.0 °C, 108.0 °C, 109.0 °C, or 110.0 °C. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0027] In some alternative examples, the time of the reflux reaction is 4 - 5 h. For example, it can be 4.0 h, 4.1 h, 4.2 h, 4.3 h, 4.4 h, 4.5 h, 4.6 h, 4.7 h, 4.8 h, 4.9 h or 5.0 h. However, it is not limited to the listed values, and other unlisted values within this value range are equally applicable.

[0028] In some alternative examples, the mass - volume ratio of the heterocyclic calix[4]arene to anhydrous N,N - dimethylformamide is 1 g : 40 mL.

[0029] In some alternative examples, the mass ratio of the heterocyclic calix[4]arene to potassium carbonate is 5 : 3.

[0030] In some alternative examples, the mass - volume ratio of the heterocyclic calix[4]arene to the chloromethyl(diphenyl)phosphine solution is 1 g : 10 mL.

[0031] In some alternative examples, the mass fraction of the chloromethyl(diphenyl)phosphine solution is 6 wt.%, and the solvent is anhydrous N,N - dimethylformamide.

[0032] In some alternative examples, the second temperature is 50 - 60 °C. For example, it can be 50.0 °C, 51.0 °C, 52.0 °C, 53.0 °C, 54.0 °C, 55.0 °C, 56.0 °C, 57.0 °C, 58.0 °C, 59.0 °C or 60.0 °C. However, it is not limited to the listed values, and other unlisted values within this value range are equally applicable.

[0033] In some alternative examples, the stirring reaction time at the second temperature is 12 - 13 h. For example, it can be 12.0 h, 12.1 h, 12.2 h, 12.3 h, 12.4 h, 12.5 h, 12.6 h, 12.7 h, 12.8 h, 12.9 h or 13.0 h. However, it is not limited to the listed values, and other unlisted values within this value range are equally applicable.

[0034] As a preferred technical solution of the present invention, in step S2, the mass - volume ratio of the phosphonic calix[4]arene to anhydrous toluene is 3 g : 100 mL.

[0035] In some alternative examples, the mass ratio of the phosphonic calix[4]arene to triethylamine is 3 : 1.

[0036] In some alternative examples, the mass ratio of the phosphonic calix[4]arene to 3 - chloropropyltriethoxysilane is 12 : 5.

[0037] In some alternative examples, the third temperature is 40 - 50 °C. For example, it can be 40.0 °C, 41.0 °C, 42.0 °C, 43.0 °C, 44.0 °C, 45.0 °C, 46.0 °C, 47.0 °C, 48.0 °C, 49.0 °C or 50.0 °C. However, it is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0038] In some alternative examples, the stirring reaction time at the third temperature is 6 - 7 h. For example, it can be 6.0 h, 6.1 h, 6.2 h, 6.3 h, 6.4 h, 6.5 h, 6.6 h, 6.7 h, 6.8 h, 6.9 h or 7.0 h. However, it is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0039] In some alternative examples, the mass - volume ratio of the crude product to anhydrous dimethyl sulfoxide is 7 g:200 mL.

[0040] In some alternative examples, the mass ratio of the crude product to zinc chloride is 70:3.

[0041] In some alternative examples, the stirring reaction time after adding zinc chloride is 1 - 2 h. For example, it can be 1.0 h, 1.1 h, 1.2 h, 1.3 h, 1.4 h, 1.5 h, 1.6 h, 1.7 h, 1.8 h, 1.9 h or 2.0 h. However, it is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0042] As a preferred technical solution of the present invention, in step S3, the mass ratio of choline chloride to glycerol is 5:9; In some alternative examples, the fourth temperature is 80 - 90 °C. For example, it can be 80.0 °C, 81.0 °C, 82.0 °C, 83.0 °C, 84.0 °C, 85.0 °C, 86.0 °C, 87.0 °C, 88.0 °C, 89.0 °C or 90.0 °C. However, it is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0043] In some alternative examples, the stirring time while maintaining the fourth temperature is 30 - 40 min. For example, it can be 30.0 min, 31.0 min, 32.0 min, 33.0 min, 34.0 min, 35.0 min, 36.0 min, 37.0 min, 38.0 min, 39.0 min or 40.0 min. However, it is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0044] In some alternative examples, the fifth temperature is 50 - 60 °C, for example, it can be 50.0 °C, 51.0 °C, 52.0 °C, 53.0 °C, 54.0 °C, 55.0 °C, 56.0 °C, 57.0 °C, 58.0 °C, 59.0 °C or 60.0 °C. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0045] In some alternative examples, the sixth temperature is 40 - 42 °C, for example, it can be 40.0 °C, 40.2 °C, 40.4 °C, 40.6 °C, 40.8 °C, 41.0 °C, 41.2 °C, 41.4 °C, 41.6 °C, 41.8 °C or 42.0 °C. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0046] In some alternative examples, the mass fraction of the nickel nitrate dispersion is 4 wt.%, and the solvent is anhydrous N,N - dimethylformamide.

[0047] In some alternative examples, the mass ratio of choline chloride, 1 - butyl - 3 - methylimidazolium bis(trifluoromethylsulfonyl)imide, glycidyl acrylate, nickel nitrate dispersion, N,N - methylenebisacrylamide to azobisisobutyronitrile is 20:40:10:40:4:1.

[0048] In some alternative examples, the mass - to - volume ratio of azobisisobutyronitrile to absolute ethanol is 1 g:40 mL.

[0049] As a preferred technical solution of the present invention, in step S4, the mass fraction of the metal - coordinated calix[4]arene solution is 10 wt.%, and the solvent is anhydrous toluene.

[0050] In some alternative examples, the time for maintaining the vacuum is 20 - 30 min, and the number of cycles is 3 times. For example, it can be 20.0 min, 21.0 min, 22.0 min, 23.0 min, 24.0 min, 25.0 min, 26.0 min, 27.0 min, 28.0 min, 29.0 min or 30.0 min. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0051] In some alternative examples, the holding time of the fifth temperature is 2 - 3 h. For example, it can be 2.0 h, 2.1 h, 2.2 h, 2.3 h, 2.4 h, 2.5 h, 2.6 h, 2.7 h, 2.8 h, 2.9 h or 3.0 h. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0052] In some alternative examples, the fourth temperature holding time is 1 - 2 h, for example, it can be 1.0 h, 1.1 h, 1.2 h, 1.3 h, 1.4 h, 1.5 h, 1.6 h, 1.7 h, 1.8 h, 1.9 h or 2.0 h, but is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0053] In a second aspect, the present invention provides a silicon - based adsorbent for oil - gas recovery prepared by using the preparation method described in the first aspect.

[0054] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) It improves the multifunctional adsorption ability of the adsorbent for complex components of oil - gas. The rigid aromatic skeleton of the metal - coordinated calix[4]arene realizes high - selective adsorption of aromatic molecules, and the ionic liquid mixture further expands the adaptability of the adsorbent. Through π - π stacking interaction, electrostatic interaction and hydrogen - bond complexation, it interacts with unsaturated molecules, heteroatom - containing compounds and polar - end - group molecules, improving the overall performance of the adsorbent; (2) The present invention improves the selectivity and adsorption capacity of the adsorbent. Through the molecular recognition property of calix[4]arene, the adsorbent can accurately capture aromatic molecules with specific structures, and the hydrogen - bond network formed by the imidazole cation and bis(trifluoromethylsulfonyl)imide anion in the ionic liquid mixture binding glycerol further enhances the selectivity for polar and unsaturated molecules. In addition, due to the low vapor pressure and excellent solubility of the ionic liquid mixture, the ability of the adsorbent to capture volatile molecules in oil - gas is enhanced, thus effectively reducing oil - gas loss and improving resource utilization rate; (3) The π - π stacking interaction between calix[4]arene and aromatic molecules in the adsorbent and the hydrogen - bond and electrostatic interactions between the ionic liquid mixture and target molecules are all non - covalent interactions with low binding energy. The adsorption and desorption processes are highly reversible. By moderately increasing the temperature and evacuating the vacuum, the interaction can be broken to achieve the desorption of molecules and the regeneration of the adsorbent. Each component of the adsorbent exhibits excellent thermal stability and chemical stability, is not easily decomposed or volatilized, ensuring the stability of the adsorbent performance during multiple adsorption - desorption cycles. Description of the Drawings

[0055] Figure 1 SEM image of the silicon - based adsorbent prepared in Example 1 of the present invention; Figure 2 TEM image of the silicon - based adsorbent prepared in Example 1 of the present invention. Detailed Embodiments

[0056] The technical solution of the present invention will be described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments described herein are specific specific embodiments of the present invention and are used to illustrate the concept of the present invention; these descriptions are all explanatory and exemplary and should not be construed as limiting the embodiments of the present invention and the protection scope of the present invention. Except for the embodiments described herein, those skilled in the art can also adopt other obvious technical solutions based on the content disclosed in the claims and the specification of this application. These technical solutions include technical solutions that make any obvious substitutions and modifications to the embodiments described herein.

[0057] The chemical reagents used in the embodiments and comparative examples of the present invention are all commercially available products and have not been further purified.

[0058] Example 1 This example provides a preparation method of a silicon-based adsorbent for oil and gas recovery. The preparation method specifically includes the following steps: A1. Mix 4 mL of tetraethoxysilane with 20 mL of an ethanol aqueous solution evenly, then add 1 mL of 0.1 M hydrochloric acid solution and stir. The volume ratio of absolute ethanol to deionized water in the ethanol aqueous solution is 4:1. After stirring evenly, add 0.6 g of CTAB, stir and mix, then transfer to a water bath condition, adjust the temperature to 44 °C and let it stand for 12.2 h. After drying the product, soak it in a hydrochloric acid-ethanol solution for 7.2 h. The volume ratio of absolute ethanol to hydrochloric acid in the hydrochloric acid-ethanol solution is 10:1. After soaking, wash and dry to obtain a porous silicon material; S1. Under a nitrogen atmosphere, disperse 1 g of calix[4]arene in 50 mL of anhydrous N,N-dimethylformamide. After dispersing evenly, add 0.75 g of potassium carbonate, then add 12.5 mL of a 4.5 wt.% 4-bromomethylpyridine solution, adjust the temperature to 102 °C and reflux for 4.2 h. After the reaction, extract and dry to obtain a heterocyclic calix[4]arene. Then disperse 1 g of the heterocyclic calix[4]arene in 40 mL of anhydrous N,N-dimethylformamide. After dispersing evenly, add 0.6 g of potassium carbonate, then add 10 mL of a 6 wt.% chloromethyl(diphenyl)phosphine solution, adjust the temperature to 55 °C and stir for 12.3 h. After the reaction, extract and dry to obtain a phosphine calix[4]arene; S2. Disperse 3 g of the phosphine calix[4]arene in 100 mL of anhydrous toluene, add 1 g of triethylamine and stir evenly, then add 1.25 g of 3-chloropropyltriethoxysilane, adjust the temperature to 48 °C and stir for 6.3 h. After the reaction, extract and dry to obtain a crude product. Then disperse 0.7 g of the crude product in 20 mL of anhydrous dimethyl sulfoxide, add 0.03 g of zinc chloride and stir for 1.5 h to obtain a metal-coordinated calix[4]arene; S3. After mixing 10 g of choline chloride with 18 g of glycerol, adjust the temperature to 81 °C under water bath conditions and keep stirring for 30 min, then transfer to a nitrogen purge condition, adjust the temperature to 58 °C and maintain it to obtain a mother liquor. Add 20 g of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide to the mother liquor, fully mix, then add 5 g of glycidyl acrylate, adjust the temperature to 41 °C and maintain nitrogen purge to obtain an intermediate mixture. Add 20 g of a 4 wt.% nickel nitrate dispersion to the intermediate mixture, adjust the temperature to 57 °C and stir to obtain an intermediate mixture containing Ni 2+ of the intermediate mixture. Disperse 2.0 g of N,N'-methylenebisacrylamide and 0.5 g of azobisisobutyronitrile in 20 mL of absolute ethanol and then add to the intermediate mixture containing Ni 2+ to obtain an ionic liquid mixture; S4. Immerse the porous silicon material in a 10 wt.% solution of metal-coordinated calix[4]arene, adjust the temperature to 82 °C, evacuate and maintain for 22 min, then return to atmospheric pressure and repeat 3 times. After soaking, take out and dry, then soak in the ionic liquid mixture. Adjust the temperature to 55 °C and maintain for 2.7 h, then adjust the temperature to 88 °C and maintain for 1.4 h. After soaking, take out and dry to obtain a silicon-based adsorbent for oil and gas recovery.

[0059] Figure 1 This is the SEM image of the silicon-based adsorbent prepared in this example. It can be seen that the silicon-based adsorbent has a porous structure, which can provide a large specific surface area during the oil and gas adsorption process; Figure 2 This is the TEM image of the silicon-based adsorbent prepared in this example.

[0060] Example 2

[0061] This example provides a preparation method of a silicon-based adsorbent for oil and gas recovery. The preparation method specifically includes the following steps: A1. Mix 4 mL of tetraethoxysilane with 20 mL of an ethanol aqueous solution evenly, then add 1 mL of 0.1 M hydrochloric acid solution and stir. The volume ratio of absolute ethanol to deionized water in the ethanol aqueous solution is 4:1. After stirring evenly, add 0.6 g of CTAB, stir and mix, then transfer to a water bath condition, adjust the temperature to 41 °C and let it stand for 12.9 h. After drying the product, soak it in a hydrochloric acid-ethanol solution for 6.4 h. The volume ratio of absolute ethanol to hydrochloric acid in the hydrochloric acid-ethanol solution is 10:1. After soaking, wash and dry to obtain a porous silicon material; S1. Under a nitrogen atmosphere, 1 g of calix[4]arene is dispersed in 50 mL of anhydrous N,N-dimethylformamide. After uniform dispersion, 0.75 g of potassium carbonate is added, followed by 12.5 mL of a 4.5 wt.% 4-bromomethylpyridine solution. The temperature is adjusted to 109 °C and refluxed for 4.8 h. After the reaction, extraction and drying are carried out to obtain heterocyclic calix[4]arene. Then, 1 g of the heterocyclic calix[4]arene is dispersed in 40 mL of anhydrous N,N-dimethylformamide. After uniform dispersion, 0.6 g of potassium carbonate is added, followed by 10 mL of a 6 wt.% chloromethyl(diphenyl)phosphine solution. The temperature is adjusted to 51 °C and stirred for 12.9 h. After the reaction, extraction and drying are carried out to obtain phosphine calix[4]arene; S2. 3 g of phosphine calix[4]arene is dispersed in 100 mL of anhydrous toluene. 1 g of triethylamine is added and stirred evenly, followed by 1.25 g of 3-chloropropyltriethoxysilane. The temperature is adjusted to 40 °C and stirred for 6.8 h. After the reaction, extraction and drying are carried out to obtain the crude product. Then, 0.7 g of the crude product is dispersed in 20 mL of anhydrous dimethyl sulfoxide, and 0.03 g of zinc chloride is added and stirred for 1.2 h to obtain metal-coordinated calix[4]arene; S3. After mixing 10 g of choline chloride and 18 g of glycerol, the temperature is adjusted to 88 °C under a water bath condition and stirred for 38 min, then transferred to a nitrogen purging condition, and the temperature is adjusted to 52 °C and maintained to obtain the mother liquor. 20 g of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide is added to the mother liquor, and after thorough mixing, 5 g of glycidyl acrylate is added. The temperature is adjusted to 42 °C and nitrogen purging is maintained to obtain the intermediate mixture. 20 g of a 4 wt.% nickel nitrate dispersion is added to the intermediate mixture, and the temperature is adjusted to 51 °C and stirred to obtain an intermediate mixture containing Ni 2+ After dispersing 2.0 g of N,N-methylenebisacrylamide and 0.5 g of azobisisobutyronitrile in 20 mL of anhydrous ethanol, it is added to the intermediate mixture containing Ni 2+ to obtain the ionic liquid mixture; S4. The porous silicon material is immersed in a 10 wt.% metal-coordinated calix[4]arene solution. The temperature is adjusted to 88 °C, evacuated and maintained for 28 min, then returned to normal pressure and cycled 3 times. After soaking, it is taken out and dried, and then soaked in the ionic liquid mixture. The temperature is adjusted to 59 °C and maintained for 2.2 h, and then the temperature is adjusted to 81 °C and maintained for 1.9 h. After soaking, it is taken out and dried to obtain a silicon-based adsorbent for oil and gas recovery.

[0062] Example 3

[0063] This example provides a preparation method of a silicon-based adsorbent for oil and gas recovery. The preparation method specifically includes the following steps: A1. Mix 4 mL of tetraethoxysilane with 20 mL of an ethanol aqueous solution evenly, then add 1 mL of 0.1 M hydrochloric acid solution and stir. The volume ratio of absolute ethanol to deionized water in the ethanol aqueous solution is 4:1. After stirring evenly, add 0.6 g of CTAB, stir and mix, then transfer to a water bath condition, adjust the temperature to 49 °C and let it stand for 12.4 h. After drying the product, soak it in a hydrochloric acid - ethanol solution for 7.9 h. The volume ratio of absolute ethanol to hydrochloric acid in the hydrochloric acid - ethanol solution is 10:1. After soaking, wash and dry to obtain a porous silicon material; S1. Under a nitrogen atmosphere, disperse 1 g of calix[4]arene in 50 mL of anhydrous N,N - dimethylformamide. After dispersing evenly, add 0.75 g of potassium carbonate, then add 12.5 mL of 4.5 wt.% 4 - bromomethylpyridine solution, adjust the temperature to 106 °C and reflux for 4.5 h. After the reaction, extract and dry to obtain heterocyclic calix[4]arene. Then disperse 1 g of heterocyclic calix[4]arene in 40 mL of anhydrous N,N - dimethylformamide, add 0.6 g of potassium carbonate after dispersing evenly, then add 10 mL of 6 wt.% chloromethyl(diphenyl)phosphine solution, adjust the temperature to 58 °C and stir - react for 12.7 h. After the reaction, extract and dry to obtain phosphine - calix[4]arene; S2. Disperse 3 g of phosphine - calix[4]arene in 100 mL of anhydrous toluene, add 1 g of triethylamine and stir evenly, then add 1.25 g of 3 - chloropropyltriethoxysilane, adjust the temperature to 47 °C and stir - react for 6.1 h. After the reaction, extract and dry to obtain a crude product. Then disperse 0.7 g of the crude product in 20 mL of anhydrous dimethyl sulfoxide, add 0.03 g of zinc chloride and stir - react for 1.9 h to obtain metal - coordinated calix[4]arene; S3. Mix 10 g of choline chloride with 18 g of glycerol, adjust the temperature to 84 °C under a water bath condition and keep stirring for 36 min, then transfer to a nitrogen - purging condition, adjust the temperature to 54 °C and keep it to obtain a mother liquor. Add 20 g of 1 - butyl - 3 - methylimidazolium bis(trifluoromethylsulfonyl)imide to the mother liquor, mix well, then add 5 g of glycidyl acrylate, adjust the temperature to 40 °C and keep nitrogen purging to obtain an intermediate mixture. Add 20 g of 4 wt.% nickel nitrate dispersion to the intermediate mixture, adjust the temperature to 59 °C and stir to obtain an intermediate mixture containing Ni 2+ After dispersing 2.0 g of N,N - methylenebisacrylamide and 0.5 g of azobisisobutyronitrile in 20 mL of absolute ethanol, add them to the intermediate mixture containing Ni 2+ to obtain an ionic liquid mixture; S4. Immerse the porous silicon material in a 10 wt.% metal-coordinated calix[4]arene solution, adjust the temperature to 83 °C, evacuate and maintain for 26 min, then return to normal pressure and cycle 3 times. After the immersion is completed, take out and dry, then immerse in the ionic liquid mixture. Adjust the temperature to 57 °C and maintain for 2.6 h, then adjust the temperature to 87 °C and maintain for 1.2 h. After the immersion is completed, take out and dry to obtain a silicon-based adsorbent for oil and gas recovery.

[0064] Example 4

[0065] This example provides a preparation method of a silicon-based adsorbent for oil and gas recovery. The preparation method specifically includes the following steps: A1. Mix 4 mL of tetraethoxysilane with 20 mL of an ethanol aqueous solution evenly, then add 1 mL of 0.1 M hydrochloric acid solution and stir. The volume ratio of absolute ethanol to deionized water in the ethanol aqueous solution is 4:1. After stirring evenly, add 0.6 g of CTAB, stir and mix, then transfer to a water bath condition, adjust the temperature to 46 °C and let stand for 12.7 h. After drying the product, immerse it in a hydrochloric acid-ethanol solution for 6.8 h. The volume ratio of absolute ethanol to hydrochloric acid in the hydrochloric acid-ethanol solution is 10:1. After the immersion is completed, wash and dry to obtain a porous silicon material; S1. Under a nitrogen atmosphere, disperse 1 g of calix[4]arene in 50 mL of anhydrous N,N-dimethylformamide, add 0.75 g of potassium carbonate after dispersion, then add 12.5 mL of a 4.5 wt.% 4-bromomethylpyridine solution, adjust the temperature to 105 °C and reflux for 4.6 h. After the reaction is completed, extract and dry to obtain heterocyclic calix[4]arene. Then disperse 1 g of heterocyclic calix[4]arene in 40 mL of anhydrous N,N-dimethylformamide, add 0.6 g of potassium carbonate after dispersion, then add 10 mL of a 6 wt.% chloromethyl(diphenyl)phosphine solution, adjust the temperature to 53 °C and stir for 12.1 h. After the reaction is completed, extract and dry to obtain phosphine-based calix[4]arene; S2. Disperse 3 g of phosphine-based calix[4]arene in 100 mL of anhydrous toluene, add 1 g of triethylamine and stir evenly, then add 1.25 g of 3-chloropropyltriethoxysilane, adjust the temperature to 44 °C and stir for 6.6 h. After the reaction is completed, extract and dry to obtain a crude product. Then disperse 0.7 g of the crude product in 20 mL of anhydrous dimethyl sulfoxide, add 0.03 g of zinc chloride and stir for 1.6 h to obtain metal-coordinated calix[4]arene; S3. Mix 10 g of choline chloride with 18 g of glycerol, adjust the temperature to 87 °C under water bath conditions and keep stirring for 33 min, then transfer to a nitrogen purge condition, adjust the temperature to 59 °C and maintain it to obtain a mother liquor. Add 20 g of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide to the mother liquor, mix well, then add 5 g of glycidyl acrylate, adjust the temperature to 41 °C and maintain nitrogen purge to obtain an intermediate mixture. Add 20 g of a 4 wt.% nickel nitrate dispersion to the intermediate mixture, adjust the temperature to 53 °C and stir to obtain an intermediate mixture containing Ni 2+ in it. Disperse 2.0 g of N,N'-methylenebisacrylamide and 0.5 g of azobisisobutyronitrile in 20 mL of absolute ethanol, and then add it to the intermediate mixture containing Ni 2+ in it to obtain an ionic liquid mixture; S4. Immerse the porous silicon material in a 10 wt.% solution of metal-coordinated calix[4]arene, adjust the temperature to 89 °C, evacuate and maintain for 21 min, then return to normal pressure and repeat 3 times. After soaking, take it out, dry it, and then soak it in the ionic liquid mixture. Adjust the temperature to 51 °C and maintain for 2.9 h, then adjust the temperature to 83 °C and maintain for 1.6 h. After soaking, take it out, dry it to obtain a silicon-based adsorbent for oil and gas recovery.

[0066] Comparative Example 1 This comparative example provides a preparation method of a silicon-based adsorbent for oil and gas recovery. The difference from Example 1 is that in S1, the volume of the chloromethyl(diphenyl)phosphine solution is 20 mL, which is 10 mL more than that in Example 1, and other process parameters and operating conditions are exactly the same as those in Example 1.

[0067] Comparative Example 2 This comparative example provides a preparation method of a silicon-based adsorbent for oil and gas recovery. The difference from Example 1 is that in S1, the volume of the chloromethyl(diphenyl)phosphine solution is 1 mL, which is 9 mL less than that in Example 1, and other process parameters and operating conditions are exactly the same as those in Example 1.

[0068] Comparative Example 3 This comparative example provides a preparation method of a silicon-based adsorbent for oil and gas recovery. The difference from Example 1 is that in S3, the mass of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide is 40 g, which is 20 g more than that in Example 1, and other process parameters and operating conditions are exactly the same as those in Example 1.

[0069] Comparative Example 4 This comparative example provides a method for preparing a silicon-based adsorbent for oil and gas recovery. The difference from Example 1 lies in that in S3, the mass of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide is 1 g, which is 19 g less than that in Example 1, and other process parameters and operating conditions are exactly the same as those in Example 1.

[0070] The oil and gas adsorption test method in the present invention is as follows: Nitrogen is used to purge the n-hexane saturated vapor, and the purge speed is 10 mL·min -1 , which is introduced into a silicon-based adsorption column (the diameter of the adsorption column is 50 mm and the height of the adsorption column is 150 mm) containing 50 g. The oil and gas concentration at the outlet of the adsorption column is detected by a combustible gas detector; Desorption process: Close the outlet valve, and use a vacuum pump to perform vacuum desorption for 15 min; The cyclic retention rate is the retention rate compared with the first adsorption amount after 4 adsorption and desorption cycles at 30 °C. The test results are shown in Table 1.

[0071] Table 1 Test results of Examples 1-4 and Comparative Examples 1-4 for preparing silicon-based adsorbents for oil and gas recovery

[0072] As can be seen from Table 1, compared with Example 1, the adsorption amounts at 30 °C and 60 °C and the cyclic retention rate of Comparative Example 1 are all reduced; the adsorption amounts at 30 °C and 60 °C and the cyclic retention rate of Comparative Example 2 are all reduced. This is because in Comparative Example 1, the excessive use of chloromethyl(diphenyl)phosphine will lead to too high a phosphine group density on the surface of the calix[4]arene molecule. The phosphine group is a functional group with strong nucleophilicity, and when its density is too high, a strong steric hindrance effect will be generated, thereby reducing the adsorption ability of calix[4]arene for alkanes, and at the same time increasing the non-uniformity of the adsorbent surface, resulting in a decline in the cyclic performance. In Comparative Example 2, the amount of chloromethyl(diphenyl)phosphine is insufficient, the adsorption efficiency of phosphine-calix[4]arene is reduced, and the phosphine group is an important functional group providing coordination sites, which will reduce the metal coordination effect of the adsorbent, and the capture ability of the adsorbent for polar molecules in oil and gas will decline, and the cyclic performance will decrease.

[0073] Compared with Example 1, the adsorption amounts at 30 °C and 60 °C and the cyclic retention rate of Comparative Example 3 are all reduced; the adsorption amounts at 30 °C and 60 °C and the cyclic retention rate of Comparative Example 4 are all reduced. In Comparative Example 3, there is too much 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, which may form an overly thick ionic liquid layer on the surface of the adsorbent, shielding other important adsorption sites (metal coordination centers or phosphine functional groups), thereby reducing the total adsorption performance of the adsorbent. In Comparative Example 4, there is too little 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, resulting in a weakening of the overall polarity and π-π interaction ability of the ionic liquid, reducing the physical adsorption ability between the adsorbent surface and oil and gas components, and reducing the capture ability of the adsorbent for aromatic components.

[0074] The above are only specific embodiments 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 thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A method for preparing a silicon-based adsorbent for oil and gas recovery, characterized in that: The preparation method comprises: S1, dispersing calix[4]arene in anhydrous N,N-dimethylformamide, adding potassium carbonate and 4-bromomethylpyridine solution, and reacting to obtain heterocyclic calix[4]arene; dispersing heterocyclic calix[4]arene in anhydrous N,N-dimethylformamide, adding potassium carbonate and chloromethyl (diphenyl)phosphine solution, and reacting to obtain phosphinocalix[4]arene; S2, dispersing the phosphinocalix[4]arene in anhydrous toluene, adding triethylamine and 3-chloropropyltriethoxysilane, reacting to obtain a crude product, and then dispersing the crude product in anhydrous dimethyl sulfoxide, adding zinc chloride to react to obtain a metal coordinated calix[4]arene; S3, after mixing choline chloride and glycerol, adjusting the temperature to obtain a mother liquor, adding 1-butyl-3-methylimidazole bistrifluoromethanesulfonyl imide salt and glycidyl acrylate to obtain an intermediate mixed solution, adding nickel nitrate dispersion to the intermediate mixed solution to obtain a Ni-containing 2+ The intermediate mixture is prepared by dispersing N,N-methylenebisacrylamide and azobisisobutyronitrile in anhydrous ethanol and then adding Ni 2+ An intermediate mixed solution is obtained to obtain an ionic liquid mixed solution; S4, immersing the porous silicon material in a metal coordination calix[4]arene solution, taking it out after immersion, drying it, and then immersing it in an ionic liquid mixture to obtain a silicon-based adsorbent for oil and gas recovery; The mass volume ratio of the heterocyclic calix[4]arene to the chloromethyl(diphenyl)phosphine solution is 1 g:10 mL.

2. The method for preparing a silicon-based adsorbent for oil and gas recovery according to claim 1, characterized in that: In S4, the preparation method of the porous silicon material is: A1, tetraethoxysilane is mixed with ethanol aqueous solution, hydrochloric acid solution and CTAB are added, and the mixture is transferred to a water bath and allowed to stand. The product is dried and immersed in a hydrochloric acid-ethanol solution. After the immersion is completed, the porous silicon material is washed and dried to obtain the porous silicon material.

3. The method for preparing a silicon-based adsorbent for oil and gas recovery according to claim 1, characterized in that: In S1: The mass ratio of the calix[4]arene to potassium carbonate is 4:3; The mass volume ratio of the calix[4]arene to the 4-bromomethylpyridine solution is 2 g:25 mL.

4. The method for preparing a silicon-based adsorbent for oil and gas recovery according to claim 1, characterized in that: In S1: The mass ratio of the heterocyclic calix[4]arene to potassium carbonate is 5:

3.

5. The method for preparing a silicon-based adsorbent for oil and gas recovery according to claim 1, characterized in that: In S2: The mass ratio of the phosphinocalix[4]arene to triethylamine is 3:1; The mass ratio of the phosphinocalix[4]arene to 3-chloropropyltriethoxysilane is 12:

5.

6. The method for preparing a silicon-based adsorbent for oil and gas recovery according to claim 1, characterized in that: In S2: The mass volume ratio of the crude product to anhydrous dimethyl sulfoxide is 7 g:200 mL; The mass ratio of the crude product to zinc chloride is 70:

3.

7. The method for preparing a silicon-based adsorbent for oil and gas recovery according to claim 1, characterized in that: In S3: The mass ratio of choline chloride to glycerol is 5:9; The mass ratio of the choline chloride, 1-butyl-3-methylimidazole bis(trifluoromethanesulfonyl)imide salt, glycidyl acrylate, nickel nitrate dispersion, N,N-methylenebisacrylamide and azobisisobutyronitrile is 20:40:10:40:4:

1.

8. The method for preparing a silicon-based adsorbent for oil and gas recovery according to claim 1, characterized in that: In S4: The mass fraction of the metal coordinated calix[4]arene solution is 10 wt.%, and the solvent is anhydrous toluene.

9. The method for preparing a silicon-based adsorbent for oil and gas recovery according to claim 2, characterized in that: In A1: The volume ratio of tetraethoxysilane, ethanol aqueous solution and hydrochloric acid solution is 4:20:1; The volume mass ratio of tetraethoxysilane to CTAB is 20 mL:3 g; In the hydrochloric acid-ethanol solution, the volume ratio of anhydrous ethanol to hydrochloric acid is 10:

1.

10. A silicon-based adsorbent for oil and gas recovery, characterized in that: Prepared according to the preparation method according to any one of claims 1 to 9.

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