Composite adsorbent as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of adsorption materials, and particularly relates to a composite adsorbent as well as a preparation method and application thereof. The preparation method of the composite adsorbent provided by the invention comprises the following steps: 1) circularly heating a raw material containing metal salt by using pulse current under a protective atmosphere to obtain a treated material; and 2) mixing the treated material obtained in the step 1), a molecular sieve, aluminum oxide and water, molding, drying and roasting to obtain the composite adsorbent. The composite adsorbent prepared by the preparation method provided by the invention has excellent effects of removing methanol and ether (such as dimethyl ether) at the same time.

Description

Technical Field

[0001] The present invention belongs to the technical field of adsorption materials, and in particular relates to a composite adsorbent and a preparation method and application thereof. Background Art

[0002] In the propane dehydrogenation (PDH) process, purification of the raw propane is a key step to ensure catalyst stability and reaction efficiency. Water, nitrogen compounds, and oxygenates (methanol, dimethyl ether, and methyl tert-butyl ether (MTBE)) in propane are all harmful substances that can poison, coke, or deactivate the catalyst. If the oxygenate content in propane is too high, it will accelerate the carbonization of the Pt-based catalyst and shorten the catalyst regeneration cycle. Therefore, as the raw material for the mixed alkane dehydrogenation reaction, propane must undergo a strict pretreatment process to remove oxygenates, denitrify, dehydrate, and other impurities to ensure that the content of various impurities meets the requirements of the mixed alkane dehydrogenation process. However, the existing desorption and adsorption materials for removing oxygenates from low-carbon hydrocarbons are limited in their effectiveness in simultaneously removing methanol and ether. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defect of existing desorption materials in removing oxygen-containing compounds from light hydrocarbons while removing methanol and ether at the same time, thereby providing a composite adsorbent and its preparation method and application.

[0004] The present invention provides a method for preparing a composite adsorbent, comprising the following steps:

[0005] 1) The raw material containing the metal salt is heated under a protective atmosphere using a pulsed current cycle to obtain a treated material;

[0006] 2) The treated material obtained in step 1), molecular sieve, alumina and water are mixed, shaped, dried and calcined to obtain the composite adsorbent.

[0007] Preferably, the raw material containing metal salt in step 1) comprises metal salt or organic polymer film-metal salt complex;

[0008] The metals in the raw materials containing metal salts in the present invention include, but are not limited to, sodium, potassium, zinc, copper, magnesium, calcium, manganese, and cerium.

[0009] Optionally, the metal salt includes at least one of a metal zinc salt and a metal sodium salt;

[0010] Optionally, the metal zinc salt is selected from at least one of zinc chloride and zinc nitrate;

[0011] Optionally, the organic polymer film-metal salt complex is selected from at least one of an organic polymer film-metal zinc salt complex and an organic polymer film-metal sodium salt complex;

[0012] Optionally, the organic polymer film-metal zinc salt complex is selected from at least one of an organic polymer film-zinc chloride complex and an organic polymer film-zinc nitrate complex;

[0013] Optionally, when the raw material containing metal salt is metal salt, the mass ratio of the treated material, molecular sieve, alumina and water is (0.2-0.6):1:(3.4-3.8):(2-2.5);

[0014] When the raw material containing metal salt is an organic polymer film-metal salt complex, the mass ratio of the treated material, molecular sieve, aluminum oxide and water is (0.35-0.75):1:(3.4-3.8):(2-2.5).

[0015] Preferably, the method for preparing the organic polymer film-metal zinc salt complex comprises the following steps:

[0016] S1: dissolving natural organic polymer powder in water, stirring, and drying to obtain an organic polymer film;

[0017] S2: The organic polymer film obtained in step S1 is treated with acid, and then immersed in an alcohol solution of a metal salt. After the immersion, the organic polymer film is dried and ground to obtain the organic polymer film-metal salt complex.

[0018] Preferably, in step S1, the natural organic polymer powder is selected from at least one of starch powder and its derivatives, cellulose powder and its derivatives, and sesbania powder and its derivatives;

[0019] Derivatives of starch powder and its derivatives include but are not limited to products obtained by modifying starch; derivatives of cellulose powder and its derivatives include but are not limited to products obtained by modifying cellulose; derivatives of sesbania gum powder and its derivatives include but are not limited to products obtained by modifying sesbania gum powder; derivatives of konjac gum powder and its derivatives include but are not limited to products obtained by modifying konjac gum powder; derivatives of guar gum powder and its derivatives include but are not limited to products obtained by modifying guar gum powder; derivatives of tamarind gum powder and its derivatives include but are not limited to products obtained by modifying tamarind gum powder; and derivatives of xanthan gum powder and its derivatives include but are not limited to products obtained by modifying xanthan gum powder.

[0020] The mass ratio of the natural organic polymer powder to water is 1:(50-100);

[0021] In step S1, natural organic polymer powder is dissolved in water, stirred and swelled to a viscous state, and then applied to a glass plate and dried to obtain an organic polymer film;

[0022] The stirring treatment temperature is 45-55°C, the stirring treatment speed is 400-600rpm, and the stirring treatment time is 3-5h;

[0023] In step S1, the drying temperature is 65° C.-75° C., and the drying time is not specifically limited, as long as the purpose of removing water molecules is achieved. Optionally, the drying time is 2-4 hours.

[0024] Preferably, the acid treatment in step S2 comprises placing the organic polymer film in an inorganic acid solution and performing a sealed heating treatment;

[0025] The inorganic acid is selected from at least one of nitric acid, hydrochloric acid and sulfuric acid;

[0026] The mass concentration of the inorganic acid in the inorganic acid solution is 2-3 mol / L;

[0027] The sealing heating treatment temperature is 70-80°C and the sealing heating time is 9-12h;

[0028] Optionally, after the sealing and heating step, a washing and drying step is further included. Optionally, the washing step includes repeatedly washing with deionized water and a 30-50 wt% ethanol aqueous solution until the pH is 7-7.2;

[0029] Optionally, the drying temperature is 65° C.-75° C., and the drying time is not specifically limited, as long as the purpose of removing water molecules is achieved. Optionally, the drying time is 2-4 hours.

[0030] Preferably, the ratio of the organic polymer film to the metal salt is 3:(0.01-0.15), expressed in g / mol;

[0031] The alcohol in the alcohol solution of the metal salt is selected from at least one of ethanol and isopropanol;

[0032] The mass concentration of the metal salt in the alcohol solution of the metal salt is 90-95%;

[0033] The immersion time is 0.5-1h;

[0034] After the impregnation step is completed, a drying step is also included.

[0035] Preferably, the protective atmosphere in step 1) comprises at least one of a nitrogen atmosphere and an argon atmosphere;

[0036] The number of cycles of the pulse current heating treatment in step 1) is 3-4 times, the single heating temperature is 190-220° C., and the single heating time is 0.1-0.3 s;

[0037] The drying temperature in step 2) is 110-130° C. and the drying time is 2-4 hours;

[0038] The calcination temperature in step 2) is 520-580°C and the calcination time is 2-4h;

[0039] The molecular sieve in step 2) is at least one selected from 13X molecular sieve, 4A molecular sieve, and 5A molecular sieve;

[0040] After the pulse current circulation heating step in step 2) is completed, the step of grinding into powder is also included.

[0041] The molding in step 2) of the present invention includes but is not limited to strip extrusion molding and ball molding.

[0042] The present invention provides a composite adsorbent, which is prepared by the above-mentioned preparation method of the composite adsorbent.

[0043] Preferably, the pore volume of the composite adsorbent is 0.36-0.63 cm 3 / g, with a specific surface area of ​​285.40-396.49m 2 / g;

[0044] Preferably, the pore volume of the composite adsorbent is 0.61-0.63 cm 3 / g, with a specific surface area of ​​392.24-396.49m 2 / g.

[0045] The present invention provides a composite adsorbent prepared by the above-mentioned preparation method or the use of the above-mentioned composite adsorbent in removing oxygen-containing compounds from light hydrocarbons;

[0046] Preferably, the oxygen-containing compounds include alcohol compounds and ether compounds;

[0047] Optionally, the oxygen-containing compound includes methanol and dimethyl ether.

[0048] The technical solution of the present invention has the following advantages:

[0049] 1. The preparation method of the composite adsorbent provided by the present invention comprises the following steps: 1) heat-treating a raw material containing a metal salt using pulsed current circulation under a protective atmosphere to obtain a treated material; 2) mixing the treated material obtained in step 1), a molecular sieve, aluminum oxide, and water, forming, drying, and calcining to obtain the composite adsorbent. The preparation method provided by the present invention uses a pulsed current circulation technique for heat treatment. Under pulse conditions, high-energy electrons in the pulsed current bombard the interface between impurity atoms and the metal oxide matrix, destroying the chemical bonds between the two, making it easier for impurity atoms to escape from the metal oxide matrix, thereby improving the purity of the subsequent zinc oxide. At the same time, the local stress field generated by the electron bombardment reduces the interfacial energy, promotes the separation of impurity particles, and further improves the purity of the subsequent metal oxide. The present invention uses metal salts as raw materials, and the metal oxide finally formed has unsaturated sites on its surface. These unsaturated sites have the ability to chemically react with other atoms or molecules, which makes the metal oxide active in the removal reaction and has a strong ability to chemically adsorb alcohols and ethers. Although molecular sieves and alumina materials are used as carriers, and alumina is also used as a molding aid, they have the characteristics of high specific surface area, high chemical stability, and easy synthesis. They can achieve good separation and adsorption, and have the ability to adsorb small amounts of alcohols and ethers. Based on the joint action of carriers and active components, molecular sieves, alumina and metal oxides work synergistically to prepare composite adsorbents that are excellent in removing methanol and ethers (such as dimethyl ether) at the same time.

[0050] 2. The present invention provides a method for preparing a composite adsorbent. The metal salt-containing raw material in step 1) comprises a metal salt or an organic polymer film-metal salt complex. The present invention allows the organic polymer film to react with the active component metal salt, binding the organic polymer film-metal salt complex by intermolecular forces. The organic polymer film-metal salt complex is then mixed with a molecular sieve and alumina. Hydrogen bonds, van der Waals forces, and electrovalent bonds are formed between the complex and the carrier (molecular sieve, alumina), which can change the internal structure of the pore structure, making the pores more complex from simple. The composite material also fills the pores of the molecular sieve to prevent the molecular sieve from collapsing during the formation process. After subsequent calcination, the natural polymer material powder volatilizes in the form of water vapor and carbon dioxide, again creating voids in the material and leaving a complex pore structure, further increasing the specific surface area of ​​the composite adsorbent and improving its adsorption capacity. At the same time, the active component is efficiently and evenly dispersed on the alumina and molecular sieve materials. The use of the organic polymer film can also improve the adhesion of the catalytic material. The resulting composite adsorbent is further effective in removing methanol and dimethyl ether.

[0051] 3. The present invention provides a method for preparing a composite adsorbent, comprising the following steps: S1: dissolving natural organic polymer powder in water, stirring, and drying to obtain an organic polymer film; S2: treating the organic polymer film obtained in step S1 with acid, then immersing it in an alcohol solution of a metal salt. After immersion, the organic polymer film is dried and ground to obtain the organic polymer film-metal zinc salt complex. The natural organic polymer is prepared into a film, then treated with acid, and then impregnated with a metal salt. Preparing the film first facilitates subsequent pulsed heating reactions and evenly disperses the active components, exposing more reactive sites on the natural polymer. Subsequently, an acidolysis reaction occurs in an inorganic acid environment, breaking the molecular chains and destroying the original particle structure, resulting in a porous state. This facilitates more uniform loading of the active components. The composite adsorbent is prepared using the organic polymer film-metal zinc salt complex prepared by the specific preparation method as a raw material. The resulting composite adsorbent further enhances the simultaneous removal of methanol and dimethyl ether, thereby achieving more efficient desorption. DETAILED DESCRIPTION

[0052] The following examples are provided for a better understanding of the present invention and are not intended to limit the best mode of implementation. They do not limit the content and scope of protection of the present invention. Any product identical or similar to the present invention obtained by anyone under the guidance of the present invention or by combining the features of the present invention with other prior arts shall fall within the scope of protection of the present invention.

[0053] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments is not specified, they are all commercially available conventional reagents.

[0054] Example 1

[0055] This embodiment provides a method for preparing a composite adsorbent, comprising the following steps:

[0056] 1) 3g of natural organic polymer sesbania gum powder was dissolved in 50 times of deionized water and stirred at 45°C for 3h at a stirring speed of 500rpm, and then dried at 65°C to obtain an organic polymer film; the obtained organic polymer film was placed in a sealed 2.5mol / L hydrochloric acid aqueous solution, heated to 70°C for 9h, repeatedly washed with water and 40wt% ethanol aqueous solution to pH 7, dried at 65°C, and then immersed in a zinc chloride ethanol solution with a zinc chloride content of 0.05mol at 25°C for 0.5-1h, wherein the mass concentration of zinc chloride in the zinc chloride ethanol solution was 90%. After the immersion, the organic polymer film-metal zinc salt complex was obtained by infrared drying and grinding. The organic polymer film-metal zinc salt complex prepared above was subjected to heat treatment using pulse current cycling under argon atmosphere for 3 cycles, with a single heating temperature of 200°C and a single heating time of 0.2s to obtain a composite material, which was ground into a uniform powder to obtain a treated material;

[0057] 2) 8 g of the treated material obtained in step 1) was taken out, mixed with 20 g of 13X molecular sieve, 68 g of fast de-powder and 40 g of water, rolled, dried at 120° C. for 2 h, and then calcined at 550° C. for 2 h to obtain the composite adsorbent.

[0058] Example 2

[0059] This embodiment provides a method for preparing a composite adsorbent, comprising the following steps:

[0060] 1) 3g of natural organic polymer starch powder was dissolved in 100 times of deionized water and stirred at a stirring temperature of 50°C, a stirring time of 4h, a stirring speed of 500rpm, and then dried at 70°C to obtain an organic polymer film; the obtained organic polymer film was placed in a 2mol / L nitric acid aqueous solution, sealed and heated to 75°C for 9h, repeatedly washed with water and a 40wt% ethanol aqueous solution to pH 7, dried at 70°C, and then placed in a zinc nitrate ethanol solution with a zinc nitrate content of 0.10moL at 25°C for 0.7h, the mass concentration of zinc nitrate in the zinc nitrate ethanol solution was 95%, and after the impregnation, it was infrared dried and ground to obtain the organic polymer film-metal zinc salt complex. The organic polymer film-metal zinc salt complex prepared above was subjected to a heat treatment using a pulsed current cycle under an argon atmosphere for 3 cycles, with a single heating temperature of 200°C and a single heating time of 0.2s to obtain a composite material, which was ground into a uniform powder to obtain a treated material;

[0061] 2) 10 g of the treated material obtained in step 1) was taken out, mixed with 20 g of 13X molecular sieve, 72 g of fast de-powder and 45 g of water, rolled, dried at 120° C. for 2 h, and then calcined at 550° C. for 2 h to obtain the composite adsorbent.

[0062] Example 3

[0063] This embodiment provides a method for preparing a composite adsorbent, comprising the following steps:

[0064] 1) 3g of natural organic polymer cellulose powder was dissolved in 100 times of deionized water and stirred at a stirring temperature of 55°C, a stirring time of 5h, and a stirring speed of 600rpm, and then dried at 75°C to obtain an organic polymer film; the obtained organic polymer film was placed in a sealed 3mol / L hydrochloric acid aqueous solution and heated to 80°C for 9h, repeatedly washed with water and a 40wt% ethanol aqueous solution to pH 7, dried at 75°C, and then placed in a zinc nitrate ethanol solution with a zinc nitrate content of 0.15mol at 25°C for 1h, the mass concentration of zinc nitrate in the zinc nitrate ethanol solution being 90%, and after the impregnation, infrared drying and grinding were performed to obtain the organic polymer film-metal zinc salt complex. The organic polymer film-metal zinc salt complex prepared above was subjected to a heat treatment using a pulsed current cycle under an argon atmosphere for 3 cycles, with a single heating temperature of 200°C and a single heating time of 0.2s to obtain a composite material, which was ground into a uniform powder to obtain a treated material;

[0065] 2) 12 g of the treated material obtained in step 1) was taken out, mixed with 20 g of 13X molecular sieve, 76 g of fast de-powdering and 50 g of water, rolled, dried at 120° C. for 2 h, and then calcined at 550° C. for 2 h to obtain the composite adsorbent.

[0066] Example 4

[0067] This embodiment provides a method for preparing a composite adsorbent, comprising the following steps:

[0068] 1) 3 g of natural organic polymer sesbania powder and 0.05 mol of zinc chloride were ground and mixed at 300 rpm for 2 h to obtain a mixed powder. The mixed powder prepared above was heated under an argon atmosphere using a pulsed current cycle for 3 cycles, with a single heating temperature of 200° C. and a single heating time of 0.2 s to obtain a composite material, which was ground into a uniform powder to obtain a treated material.

[0069] 2) 8 g of the treated material obtained in step 1) was taken out, mixed with 20 g of 13X molecular sieve, 68 g of fast de-powder and 40 g of water, rolled, dried at 120° C. for 2 h, and then calcined at 550° C. for 2 h to obtain the composite adsorbent.

[0070] Example 5

[0071] This embodiment provides a method for preparing a composite adsorbent, comprising the following steps:

[0072] 1) 0.05 mol zinc chloride was heated in an argon atmosphere using a pulsed current cycle for 3 cycles, with a single heating temperature of 200° C. and a single heating time of 0.2 s to obtain a composite material, which was ground into a uniform powder to obtain a treated material;

[0073] 2) 6.814 g of the treated material obtained in step 1) was taken out, mixed with 20 g of 13X molecular sieve, 68 g of fast de-powder and 40 g of water, rolled, dried at 120° C. for 2 h, and then calcined at 550° C. for 2 h to obtain the composite adsorbent.

[0074] Comparative Example 1

[0075] This comparative example provides a method for preparing a composite adsorbent, comprising the following steps:

[0076] 20 g of 13X molecular sieve, 68 g of quick-drying powder and 40 g of water were mixed, rolled, dried at 120° C. for 2 h, and then calcined at 550° C. for 2 h to obtain the composite adsorbent.

[0077] Comparative Example 2

[0078] This comparative example provides a method for preparing a composite adsorbent, which differs from Example 5 in that in step 2), the mass of 13X molecular sieve is replaced with fast de-powder;

[0079] Comparative Example 3

[0080] This comparative example provides a method for preparing a composite adsorbent, which differs from Example 5 in that in step 2), the mass of the quick-de-powdering agent is replaced with 13X molecular sieve;

[0081] Comparative Example 4

[0082] This comparative example provides a method for preparing a composite adsorbent, comprising the following steps:

[0083] 6.814 g of zinc chloride, 20 g of 13X molecular sieve, 68 g of quick-drying powder and 40 g of water were mixed, rolled, dried at 120° C. for 2 h, and then calcined at 550° C. for 2 h to obtain the composite adsorbent.

[0084] Test Case

[0085] The composite adsorbent samples prepared in Examples 1-5 and Comparative Examples 1-4 were tested for specific surface area and pore volume after calcination using a physical adsorption instrument (ASAP2460, Micromeritics Instruments, USA). The test results are shown in Table 1. Specific surface area is an important indicator for measuring catalyst activity, adsorption performance, and reactivity.

[0086] Table 1

[0087] <![CDATA[Specific surface area (m 2 / g)]]> <![CDATA[Pore volume (cm 3 / g)]]> Example 1 386.34 0.59 Example 2 396.49 0.63 Example 3 392.24 0.61 Example 4 366.21 0.52 Example 5 285.40 0.36 Comparative Example 1 213.64 0.28 Comparative Example 2 240.37 0.35 Comparative Example 3 257.96 0.44 Comparative Example 4 227.81 0.31

[0088] Test Example 2

[0089] The composite adsorbents prepared in Examples 1-6 and Comparative Examples 1-5 were subjected to a dealcoholization and deetherification test, comprising the following steps:

[0090] The reaction tube is a hard glass tube with an inner diameter of 8 mm. The sample volume of the composite catalyst in the reaction tube is 2 mL (particle size 20-40 mesh). The raw gas contains 400 mg / m 3 Methanol, 200 mg / m 3 Propane gas of dimethyl ether; removal reaction is carried out through the reaction tube, the removal reaction conditions are: normal pressure, 25℃, reaction space velocity of 500h -1 ; Gas chromatography (Agilent 7080B) was used to detect the content of methanol and dimethyl ether in the gas after adsorption. The results of the removal rate of methanol and dimethyl ether by the composite adsorbent are shown in Table 2.

[0091] Table 2

[0092] Methanol removal rate / % Dimethyl ether removal rate / % Example 1 98.7 98.3 Example 2 100 100 Example 3 99.4 99.1 Example 4 97.6 97.4 Example 5 96.8 96.5 Comparative Example 1 82.9 82.7 Comparative Example 2 88.6 88.2 Comparative Example 3 90.2 89.5 Comparative Example 4 84.8 84.3

[0093] As can be seen from the above table, the composite adsorbent prepared in Example 2 has a better de-etherification and de-alcoholization effect because the adsorption mainly occurs at the active sites on the surface of the zinc oxide metal, and because the natural polymer organic material can effectively disperse the active metal components, the contact area between the metal active sites and the reactants is increased, and its adsorption capacity is improved; compared with Example 2, the composite adsorbents in Examples 1 and 3 have poor de-alcoholization and de-etherification effects because the amount of zinc oxide added in Example 1 is small, resulting in fewer active components in the composite adsorbent and fewer active sites for the reaction; in Example 3, the amount of zinc oxide added is large, and the relatively small loadable sites of the natural polymer material cannot effectively disperse the active components. The active components are easily accumulated during the preparation process, thereby reducing the uniformity of the composite adsorbent particles; compared with the composite adsorbents in Examples 1-3, the composite adsorbent in Example 5 has a lower specific surface area, uneven dispersion of active components, less contact area between the metal active sites and the oxygen-containing reactants, and less active component loading, which also leads to relatively low de-alcoholization and de-etherification capabilities.

[0094] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for preparing a composite adsorbent, characterized in that: The following steps are involved: 1) The raw material containing the metal salt is heated under a protective atmosphere using a pulsed current cycle to obtain a treated material; 2) The treated material obtained in step 1), molecular sieve, alumina and water are mixed, shaped, dried and calcined to obtain the composite adsorbent.

2. The method for preparing the composite adsorbent according to claim 1, wherein: The metal salt-containing raw material in step 1) includes a metal salt or an organic polymer film-metal salt complex; Optionally, the metal salt includes at least one of a metal zinc salt and a metal sodium salt; Optionally, the metal zinc salt is selected from at least one of zinc chloride and zinc nitrate; Optionally, the organic polymer film-metal salt complex is selected from at least one of an organic polymer film-metal zinc salt complex and an organic polymer film-metal sodium salt complex; Optionally, the organic polymer film-metal zinc salt complex is selected from at least one of an organic polymer film-zinc chloride complex and an organic polymer film-zinc nitrate complex; Optionally, when the raw material containing metal salt is metal salt, the mass ratio of the treated material, molecular sieve, alumina and water is (0.2-0.6):1:(3.4-3.8):(2-2.5); When the raw material containing metal salt is an organic polymer film-metal salt complex, the mass ratio of the treated material, molecular sieve, aluminum oxide and water is (0.35-0.75):1:(3.4-3.8):(2-2.5).

3. The method for preparing the composite adsorbent according to claim 2, wherein: The preparation method of the organic polymer film-metal zinc salt complex comprises the following steps: S1: dissolving natural organic polymer powder in water, stirring, and drying to obtain an organic polymer film; S2: The organic polymer film obtained in step S1 is treated with acid, and then immersed in an alcohol solution of a metal salt. After the immersion, the organic polymer film is dried and ground to obtain the organic polymer film-metal salt complex.

4. The method for preparing the composite adsorbent according to claim 3, wherein: In step S1, the natural organic polymer powder is selected from at least one of starch powder and its derivatives, cellulose powder and its derivatives, sesbania gum powder and its derivatives, konjac gum powder and its derivatives, guar gum powder and its derivatives, tamarind gum powder and its derivatives, and xanthan gum powder and its derivatives; The mass ratio of the natural organic polymer powder to water is 1:(50-100); The stirring treatment temperature is 45-55° C., the stirring treatment speed is 400-600 rpm, and the stirring treatment time is 3-5 hours.

5. The method for preparing the composite adsorbent according to claim 3 or 4, characterized in that: The acid treatment in step S2 includes placing the organic polymer film in an inorganic acid solution and sealing and heating it; The inorganic acid is selected from at least one of nitric acid, hydrochloric acid and sulfuric acid; The mass concentration of the inorganic acid in the inorganic acid solution is 2-3 mol / L; The sealing heating treatment temperature is 70-80°C and the sealing heating time is 9-12h; Optionally, after the sealing and heating treatment step is completed, the steps of washing and drying are also included.

6. The method for preparing the composite adsorbent according to any one of claims 3 to 5, characterized in that: The ratio of the organic polymer film to the metal salt is 3:(0.01-0.15), expressed in g / mol; The alcohol in the alcohol solution of the metal salt is selected from at least one of ethanol and isopropanol; The mass concentration of the metal salt in the alcohol solution of the metal salt is 90-95%; The immersion time is 0.5-1h; After the impregnation step is completed, a drying step is also included.

7. The method for preparing the composite adsorbent according to any one of claims 1 to 6, characterized in that: The protective atmosphere in step 1) includes at least one of a nitrogen atmosphere and an argon atmosphere; The number of cycles of the pulse current heating treatment in step 1) is 3-4 times, the single heating temperature is 190-220° C., and the single heating time is 0.1-0.3 s; The drying temperature in step 2) is 110-130° C. and the drying time is 2-4 hours; The calcination temperature in step 2) is 520-580°C and the calcination time is 2-4h; The molecular sieve in step 2) is at least one selected from 13X molecular sieve, 4A molecular sieve, and 5A molecular sieve; After the pulse current circulation heating step in step 2) is completed, the step of grinding into powder is also included.

8. A composite adsorbent, characterized in that The composite adsorbent is prepared by the preparation method of any one of claims 1 to 7.

9. The composite adsorbent according to claim 8, characterized in that: The pore volume of the composite adsorbent is 0.36-0.63 cm 3 / g, with a specific surface area of ​​285.40-396.49m 2 / g; Preferably, the pore volume of the composite adsorbent is 0.61-0.63 cm 3 / g, with a specific surface area of ​​392.24-396.49m 2 / g.

10. Use of the composite adsorbent prepared by the preparation method according to any one of claims 1 to 7 or the composite adsorbent according to claim 8 or 9 in removing oxygen-containing compounds from light hydrocarbons; Preferably, the oxygen-containing compounds include alcohol compounds and ether compounds; Optionally, the oxygen-containing compound includes methanol and dimethyl ether.