A silicon-based adsorbent for oil and gas recovery and its preparation method

Abstract

The present invention belongs to the technical field of oil and gas recovery, and provides a silicon-based adsorbent for oil and gas recovery and a preparation method thereof. First, calix[4]arene reacts with 4-bromomethylpyridine and chloromethyl(diphenyl)phosphine to obtain phosphine-calix[4]arene, and then reacts with 3-chloropropyltriethoxysilane and zinc chloride to obtain metal-coordinated calix[4]arene; secondly, choline chloride, glycerol, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, glycidyl acrylate and nickel ion-containing solution are mixed, and N,N-methylenebisacrylamide and azobisisobutyronitrile are introduced for reaction to obtain an ionic liquid mixture; the porous silicon material is immersed in the metal-coordinated calix[4]arene solution and the ionic liquid mixture to prepare a multifunctional composite silicon-based adsorbent to solve the problem that traditional adsorbents are 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, realize the recycling of resources, and reduce environmental pollution has become the research focus and technical problem in the petrochemical industry.

[0003] Currently, 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 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 industrial requirements. The condensation method uses refrigeration technology to directly condense 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 target components from oil and gas mixtures. 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 volatile oil and gas components on the surface of the adsorbent, enriches hydrocarbon compounds in the oil and gas on the surface of the adsorbent, and then recovers the oil and gas through a desorption process to realize 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 field of oil and gas recovery. 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 porous silicon materials, 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:

[0007] 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:

[0008] 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 soaking, wash and dry to obtain a porous silicon material;

[0009] 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 ends, 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 ends, extract and dry to obtain phosphine calix[4]arene;

[0010] 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 ends, 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;

[0011] S3. After mixing choline chloride and glycerol, adjust the temperature to the fourth temperature under water bath conditions, maintain 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;

[0012] 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 normal 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.

[0013] Calix[4]arene is composed of four phenolic rings connected by methylene bridges to form 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 generated phenolate is a strong nucleophile with a 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, presenting an active 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 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. Therefore, pyridine exhibits certain electron acceptor properties. In contrast, the aromatic compounds in 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 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 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 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.

[0014] 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 capture ability of the adsorbent for 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 adsorption capabilities for 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 capture ability for acidic molecules, enhancing the molecular recognition ability of the adsorbent, enabling it to efficiently capture complex components in oil and gas, and at the same time improving the adsorption efficiency and selectivity.

[0015] 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 the metal ion center to form a stable phosphine coordination compound. 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 modification 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 comes 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 presence of multiple phosphine groups on the periphery of calix[4]arene effectively enhances 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.

[0016] 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 the phenoxide form 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. Zinc ions become the active centers 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.

[0017] 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 the 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.

[0018] 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 bonding 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 various different characteristics simultaneously. Nickel ions, as classical 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 essentially forms a stable coordination bond by nickel ions accepting lone pairs of electrons in target molecules. 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. In this process, N,N-methylenebisacrylamide and azobisisobutyronitrile are added as crosslinking agent and free radical initiator. Under heating conditions, azobisisobutyronitrile decomposes to generate free radicals, initiating the polymerization reaction of glycidyl acrylate and N,N-methylenebisacrylamide to generate a three-dimensional crosslinked network structure with multifunctional sites. N,N-methylenebisacrylamide, as the crosslinking agent, undergoes a crosslinking reaction with acrylate monomers through its bisacrylamide groups to form 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.

[0019] The adsorbent enhances its adsorption ability for diverse components in oil and gas through the synergistic effect of metal-coordinated calix[4]arene and ionic liquid mixture. 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, not only enhancing the adsorption ability for aromatic hydrocarbon molecules but also showing 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 efficient and selective adsorption of oil and gas components with specific structures. At the same time, 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 moderate heating or vacuum pumping, thereby 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.

[0020] The ionic liquid mixture in synergistic action 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 and be able to capture various chemical components in oil and gas, from non-polar to polar, from aromatic molecules to heteroatom-containing molecules. The ionic liquid mixture shows 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 action 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.

[0021] As a preferred technical solution of the present invention, in step A1, the volume ratio of the tetraethoxysilane, ethanol aqueous solution, and hydrochloric acid solution is 4:20:1.

[0022] In some optional examples, the volume ratio of absolute ethanol to deionized water in the ethanol aqueous solution is 4:1.

[0023] In some alternative examples, the concentration of the hydrochloric acid solution is 0.1 M.

[0024] In some alternative examples, the volume-to-mass ratio of tetraethoxysilane to CTAB is 20 mL: 3 g.

[0025] 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, but is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0026] In some alternative examples, in the hydrochloric acid - ethanol solution, the volume ratio of absolute ethanol to hydrochloric acid is 10:1.

[0027] 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, but is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0028] As a preferred technical solution of the present invention, in step S1, the mass - to - volume ratio of calix[4]arene to anhydrous N,N - dimethylformamide is 1 g: 50 mL.

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

[0030] In some alternative examples, the mass - to - volume ratio of calix[4]arene to 4 - bromomethylpyridine solution is 2 g: 25 mL.

[0031] In some alternative examples, the mass fraction of the 4 - bromomethylpyridine solution is 4.5 wt.%, and the solvent is anhydrous N,N - dimethylformamide.

[0032] 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, but is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0033] 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 numerical range are equally applicable.

[0034] In some alternative examples, the mass - volume ratio of the heterocyclic calix[4]arene to anhydrous N,N - dimethylformamide is 1 g : 40 mL.

[0035] In some alternative examples, the mass ratio of the heterocyclic calix[4]arene to potassium carbonate is 5 : 3.

[0036] 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.

[0037] In some alternative examples, the mass fraction of the chloromethyl(diphenyl)phosphine solution is 6 wt.%, and the solvent is anhydrous N,N - dimethylformamide.

[0038] 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 numerical range are equally applicable.

[0039] 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 numerical range are equally applicable.

[0040] 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.

[0041] In some alternative examples, the mass ratio of the phosphonic calix[4]arene to triethylamine is 3 : 1.

[0042] In some alternative examples, the mass ratio of the phosphonic calix[4]arene to 3 - chloropropyltriethoxysilane is 12 : 5.

[0043] 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.

[0044] 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.

[0045] In some alternative examples, the mass - volume ratio of the crude product to anhydrous dimethyl sulfoxide is 7 g:200 mL.

[0046] In some alternative examples, the mass ratio of the crude product to zinc chloride is 70:3.

[0047] 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.

[0048] As a preferred technical solution of the present invention, in step S3, the mass ratio of choline chloride to glycerol is 5:9;

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] In some alternative examples, the mass fraction of the nickel nitrate dispersion is 4 wt.%, and the solvent is anhydrous N,N - dimethylformamide.

[0054] 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.

[0055] In some alternative examples, the mass - to - volume ratio of azobisisobutyronitrile to absolute ethanol is 1 g:40 mL.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] In some alternative embodiments, 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. However, it is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0060] In a second aspect, the present invention provides a silicon - based adsorbent for oil - gas recovery prepared by the preparation method described in the first aspect.

[0061] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) It improves the multi - functional 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, thus 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. The hydrogen - bond network formed by the imidazole cation and bis(trifluoromethanesulfonyl)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 capture ability of the adsorbent for volatile molecules in oil - gas is enhanced, thereby 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, as well as the hydrogen - bond and electrostatic interactions between the ionic liquid mixture and target molecules, are all non - covalent interactions with relatively low binding energy. The adsorption and desorption processes are highly reversible. By moderately increasing the temperature and evacuating the vacuum, the interactions can be disrupted 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 stable performance of the adsorbent during multiple adsorption - desorption cycles. Description of the Drawings

[0062] Figure 1 SEM image of the silicon - based adsorbent prepared in Example 1 of the present invention;

[0063] Figure 2 TEM image of the silicon - based adsorbent prepared in Example 1 of the present invention. Detailed Embodiments

[0064] 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.

[0065] The chemical reagents used in the embodiments and comparative examples of the present invention are all commercially available products and have not been subjected to any further purification treatment.

[0066] Example 1

[0067] This example provides a preparation method of a silicon-based adsorbent for oil and gas recovery. The preparation method specifically includes the following steps:

[0068] 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;

[0069] 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 dispersing evenly, 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, add 0.6 g of potassium carbonate after dispersing evenly, 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 phosphonium calix[4]arene;

[0070] S2. Disperse 3 g of phosphonic calix[4]arene in 100 mL of anhydrous toluene. After adding 1 g of triethylamine and stirring evenly, 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 the 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 the metal-coordinated calix[4]arene;

[0071] S3. Mix 10 g of choline chloride and 18 g of glycerol, adjust the temperature to 81 °C under water bath conditions and stir for 30 min, then transfer to a nitrogen purge condition, adjust the temperature to 58 °C and keep it. Obtain the 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 keep nitrogen purging to obtain the intermediate mixture. Add 20 g of 4 wt.% nickel nitrate dispersion to the intermediate mixture, adjust the temperature to 57 °C and stir to obtain the intermediate mixture containing Ni 2+ Disperse 2.0 g of N,N'-methylenebisacrylamide and 0.5 g of azobisisobutyronitrile in 20 mL of anhydrous ethanol, and then add them to the intermediate mixture containing Ni 2+ to obtain the ionic liquid mixture;

[0072] 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 keep it for 22 min, then return to normal pressure and repeat 3 times. After soaking, take it out and dry, then soak it in the ionic liquid mixture. Adjust the temperature to 55 °C and keep it for 2.7 h, then adjust the temperature to 88 °C and keep it for 1.4 h. After soaking, take it out and dry to obtain a silicon-based adsorbent for oil and gas recovery.

[0073] 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.

[0074] Example 2

[0075] This example provides a preparation method of a silicon-based adsorbent for oil and gas recovery. The preparation method specifically includes the following steps:

[0076] 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;

[0077] 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 109 °C and reflux for 4.8 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 51 °C and stir for 12.9 h. After the reaction, extract and dry to obtain a phosphine calix[4]arene;

[0078] 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 40 °C and stir for 6.8 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 1.2 h to obtain a metal-coordinated calix[4]arene;

[0079] S3. Mix 10 g of choline chloride with 18 g of glycerol, adjust the temperature to 88 °C under a water bath condition and keep stirring for 38 min, then transfer to a nitrogen purging condition, adjust the temperature to 52 °C and keep it. Obtain a mother liquor. Add 20 g of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide to the mother liquor, mix well, then add 5 g of glycidyl acrylate, adjust the temperature to 42 °C and keep nitrogen purging to obtain an intermediate mixture. Add 20 g of a 4 wt.% nickel nitrate dispersion to the intermediate mixture, adjust the temperature to 51 °C and stir to obtain an intermediate mixture containing Ni 2+ Disperse 2.0 g of N,N-methylenebisacrylamide and 0.5 g of azobisisobutyronitrile in 20 mL of absolute ethanol, then add them to the intermediate mixture containing Ni 2+ to obtain an ionic liquid mixture;

[0080] S4. Immerse the porous silicon material in a 10 wt.% metal-coordinated calix[4]arene solution, adjust the temperature to 88 °C, evacuate and maintain for 28 min, then return to normal pressure and cycle 3 times. After the immersion is completed, take it out, dry it, and then immerse it in the ionic liquid mixture. Adjust the temperature to 59 °C and maintain for 2.2 h, then adjust the temperature to 81 °C and maintain for 1.9 h. After the immersion is completed, take it out, dry it to obtain a silicon-based adsorbent for oil and gas recovery.

[0081] Example 3

[0082] This example provides a preparation method of a silicon-based adsorbent for oil and gas recovery. The preparation method specifically includes the following steps:

[0083] A1. Mix 4 mL of tetraethoxysilane with 20 mL of 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, immerse 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 the immersion is completed, wash and dry to obtain a porous silicon material;

[0084] 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 4.5 wt.% 4-bromomethylpyridine solution, adjust the temperature to 106 °C and reflux for 4.5 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 6 wt.% chloromethyl(diphenyl)phosphine solution, adjust the temperature to 58 °C and stir for 12.7 h. After the reaction is completed, extract and dry to obtain phosphine calix[4]arene;

[0085] 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 for 6.1 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 1.9 h to obtain metal-coordinated calix[4]arene;

[0086] S3. After mixing 10 g of choline chloride with 18 g of glycerol, adjust the temperature to 84 °C under water bath conditions and keep stirring for 36 min, then transfer to a nitrogen purging condition, adjust the temperature to 54 °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 40 °C and maintain nitrogen purging to obtain an intermediate mixture. Add 20 g of a 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+ 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 it to the intermediate mixture containing Ni 2+ to obtain an ionic liquid mixture;

[0087] S4. Immerse the porous silicon material in a 10 wt.% solution of metal-coordinated calix[4]arene, adjust the temperature to 83 °C, evacuate and maintain for 26 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 57 °C and maintain for 2.6 h, then adjust the temperature to 87 °C and maintain for 1.2 h. After soaking, take out and dry to obtain a silicon-based adsorbent for oil and gas recovery.

[0088] Example 4

[0089] This example provides a preparation method of a silicon-based adsorbent for oil and gas recovery. The preparation method specifically includes the following steps:

[0090] 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 it stand for 12.7 h. After drying the product, soak 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 soaking, wash and dry to obtain a porous silicon material;

[0091] S1, under nitrogen atmosphere, 1 g of calix[4]arene was dispersed in 50 mL of anhydrous N,N-dimethylformamide, 0.75 g of potassium carbonate was added after uniform dispersion, and then 12.5 mL of 4.5 wt.% 4-bromomethylpyridine solution was added, the temperature was adjusted to 105°C and refluxed for 4.6 h, after the reaction was completed, the heterocyclic calix[4]arene was extracted and dried to obtain heterocyclic calix[4]arene, and then 1 g of heterocyclic calix[4]arene was dispersed in 40 mL of anhydrous N,N-dimethylformamide, 0.6 g of potassium carbonate was added after uniform dispersion, and then 10 mL of 6 wt.% chloromethyl(diphenyl)phosphine solution was added, the temperature was adjusted to 53°C and stirred for 12.1 h, after the reaction was completed, the phosphine-based calix[4]arene was extracted and dried;

[0092] S2, 3 g of phosphinocalix[4]arene was dispersed in 100 mL of anhydrous toluene, 1 g of triethylamine was added and stirred evenly, and then 1.25 g of 3-chloropropyltriethoxysilane was added, and the temperature was adjusted to 44°C and stirred for 6.6 h. After the reaction was completed, the crude product was extracted and dried to obtain a crude product, and then 0.7 g of the crude product was dispersed in 20 mL of anhydrous dimethyl sulfoxide, and 0.03 g of zinc chloride was added and stirred for 1.6 h to obtain a metal-coordinated calix[4]arene;

[0093] S3, after mixing 10g of choline chloride and 18g of glycerol, the temperature was adjusted to 87°C under water bath conditions and kept stirring for 33min, and then transferred to nitrogen purge conditions, the temperature was adjusted to 59°C and kept, to obtain a mother liquor, 20g of 1-butyl-3-methylimidazole bistrifluoromethanesulfonyl imide salt was added to the mother liquor, and after fully mixing, 5g of glycidyl acrylate was added, the temperature was adjusted to 41°C and kept nitrogen purge to obtain an intermediate mixed solution, 20g of 4wt.% nickel nitrate dispersion was added to the intermediate mixed solution, the temperature was adjusted to 53°C and stirred, and Ni-containing 2+ The intermediate mixture was prepared by dispersing 2.0 g N,N-methylenebisacrylamide and 0.5 g azobisisobutyronitrile in 20 mL of anhydrous ethanol and then adding Ni 2+ An intermediate mixed solution is obtained to obtain an ionic liquid mixed solution;

[0094] S4, immerse the porous silicon material in a 10wt.% metal coordinated calix[4]arene solution, adjust the temperature to 89°C, evacuate and hold for 21 minutes, then return to normal pressure and cycle 3 times. After the immersion is completed, take out and dry it, then immerse it in an ionic liquid mixture, adjust the temperature to 51°C and hold for 2.9 hours, then adjust the temperature to 83°C and hold for 1.6 hours. After the immersion is completed, take out and dry it to obtain a silicon-based adsorbent for oil and gas recovery.

[0095] Comparative Example 1

[0096] 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 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.

[0097] Comparative Example 2

[0098] 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 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.

[0099] Comparative Example 3

[0100] 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(trifluoromethanesulfonyl)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.

[0101] Comparative Example 4

[0102] 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(trifluoromethanesulfonyl)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.

[0103] The oil and gas adsorption test method in the present invention is as follows: Nitrogen is used to purge the n-hexane saturated steam at a purge rate of 10 mL·min -1 , and it is introduced into a silicon-based adsorption column containing 50 g (the diameter of the adsorption column is 50 mm and the height of the adsorption column is 150 mm). 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 to the first adsorption amount after 4 adsorption and desorption cycles at 30°C. The test results are shown in Table 1.

[0104] Table 1 Test results of Examples 1-4 and Comparative Examples 1-4 for preparing silicon-based adsorbents for oil and gas recovery

[0105]

[0106] As can be seen from Table 1, compared with Example 1, the adsorption capacities at 30 °C and 60 °C and the cycle retention rate of Comparative Example 1 are all reduced; the adsorption capacities at 30 °C and 60 °C and the cycle 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 density of phosphino groups on the surface of calix[4]arene molecules. The phosphino 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. At the same time, it increases the non-uniformity of the adsorbent surface, resulting in a decline in the cycle performance. In Comparative Example 2, the amount of chloromethyl(diphenyl)phosphine is insufficient, the adsorption efficiency of phosphino calix[4]arene is reduced, and the phosphino group is an important functional group providing coordination sites, which will reduce the metal coordination effect of the adsorbent, the capture ability of the adsorbent for polar molecules in oil and gas decreases, and the cycle performance is reduced.

[0107] Compared with Example 1, the adsorption capacities at 30 °C and 60 °C and the cycle retention rate of Comparative Example 3 are all reduced; the adsorption capacities at 30 °C and 60 °C and the cycle retention rate of Comparative Example 4 are all reduced. In Comparative Example 3, too much 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide may form an overly thick ionic liquid layer on the surface of the adsorbent, shielding other important adsorption sites (metal coordination centers or phosphino functional groups), thereby reducing the total adsorption performance of the adsorbent. In Comparative Example 4, too little 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide leads to a weakening of the overall polarity and π-π interaction ability of the ionic liquid, reducing the physical adsorption ability between the surface of the adsorbent and the oil and gas components, and reducing the capture ability of the adsorbent for aromatic components.

[0108] 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 all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A preparation method of a silicon-based adsorbent for oil and gas recovery, characterized in that, The preparation method includes: S1. Dispersing calix[4]arene in anhydrous N,N-dimethylformamide, adding potassium carbonate and 4-bromomethylpyridine solution, reacting to obtain heterocyclic calix[4]arene; dispersing the heterocyclic calix[4]arene in anhydrous N,N-dimethylformamide, adding potassium carbonate and chloromethyl(diphenyl)phosphine solution, reacting to obtain phosphine calix[4]arene; S2. Dispersing phosphine calix[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 metal-coordinated calix[4]arene; S3. After mixing choline chloride and glycerol, adjusting the temperature to obtain a mother liquor, adding 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide and glycidyl acrylate to obtain an intermediate mixture, and adding a nickel nitrate dispersion to the intermediate mixture to obtain an intermediate mixture containing Ni 2+ of the intermediate mixture, dispersing N,N'-methylenebisacrylamide and azobisisobutyronitrile in absolute ethanol and then adding to the intermediate mixture containing Ni 2+ of the intermediate mixture to obtain an ionic liquid mixture; S4. Immersing the porous silicon material in the metal-coordinated calix[4]arene solution, taking it out and drying after immersion, and then immersing it in the 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 preparation method of 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. Mixing tetraethoxysilane with an ethanol aqueous solution, adding hydrochloric acid solution and CTAB, transferring the mixture to a water bath for static settlement after mixing, drying the product and then immersing it in a hydrochloric acid-ethanol solution, and washing and drying after immersion to obtain the porous silicon material.

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

3.

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

5.

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

1.

8. The preparation method of 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 preparation method of a silicon-based adsorbent for oil and gas recovery according to claim 2, wherein, In A1: The volume ratio of tetraethoxysilane, ethanol aqueous solution to 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 described in any one of claims 1-9.

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