Amino-modified activated carbon material, preparation method thereof and application of amino-modified activated carbon material in light hydrocarbon adsorption

Abstract

The invention relates to the technical field of VOCs treatment, and discloses an amino-modified activated carbon material, a preparation method thereof and application of the amino-modified activated carbon material in light hydrocarbon adsorption. The amino-modified activated carbon material comprises activated carbon and amino modified on the surface of the activated carbon, the specific surface area of the amino modified activated carbon material is 1500-2100 m < 2 > / g, and the pore volume is 0.6-1.1 mL / g. The amino-modified activated carbon material provided by the invention is a porous material, has a relatively large specific surface area, and can enhance physical adsorption of the amino-modified activated carbon material on light hydrocarbon and improve the adsorption capacity of the light hydrocarbon; meanwhile, amino groups are modified in the pore channels of the modified activated carbon material, the acting force between the polar group amino groups and a light hydrocarbon adsorbate is enhanced, the light hydrocarbon adsorption capacity is high, the light hydrocarbon adsorption capacity is high, and the field of treatment of VOCs with the high light hydrocarbon proportion is facilitated.

Description

Technical Field

[0001] This invention relates to the field of VOCs treatment technology, specifically to an amino-modified activated carbon material, its preparation method, and its application in the adsorption of light hydrocarbons. Background Technology

[0002] During the extraction, storage, and transportation of crude oil, VOCs emissions are inevitable. To reduce environmental pollution and improve oilfield efficiency, the effective recovery and utilization of crude oil volatiles is urgently needed. VOCs treatment technologies mainly include adsorption, liquid absorption, condensation, combustion, biological methods, and plasma methods. Adsorption technology is a simple and practical VOCs treatment technology that can not only effectively treat VOCs and solve environmental pollution problems, but also recover VOCs, creating considerable economic benefits.

[0003] Crude oil has a complex composition, and its VOCs contain a high proportion of small-molecule alkanes such as methane, ethane, and propane. Because these light hydrocarbons are nonpolar molecules with small molecular diameters and low boiling points, adsorbents have weak adsorption capacity for them, making adsorption methods for treating VOCs in oil fields challenging. By chemically modifying the surface of activated carbon, the adsorption performance of the carbon material for molecules such as ethane can be improved by utilizing the multiple van der Waals forces between the modifier and the small-molecule alkanes.

[0004] Currently, there are relevant research reports on the surface chemical modification of activated carbon. For example, Chinese patent application CN110170306A discloses a method for modifying activated carbon by simple impregnation with diethylenetriamine, resulting in modified coconut shell activated carbon with a formaldehyde concentration ≤2mg / m³. 3 The removal rate reaches 100% and can be maintained for a relatively long time. Chinese patent application CN 115245811 A discloses a method for preparing glycine-modified activated carbon. The activated carbon is first modified with traditional acid and alkali, and then modified a second time using glycine, which has a pH buffering effect, as a modifying agent. The secondary modified activated carbon has a significantly improved penetration adsorption capacity for toluene. However, in the process of VOCs treatment by adsorption, the existing modified activated carbon has low light hydrocarbon adsorption capacity, the adsorption bed is easily penetrated by light hydrocarbons, the gas emission concentration at the outlet of the adsorption tank is difficult to meet the standards, and the material granulation performance is greatly reduced. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of low adsorption capacity for light hydrocarbons and significant loss of granulation performance in existing modified activated carbon materials, and to provide an amino-modified activated carbon material, its preparation method, and its application. The amino-modified activated carbon material provided by this invention is an activated carbon material with amino-modified pore surfaces. It has a high adsorption capacity for light hydrocarbons and is suitable for application in the adsorption and recovery of crude oil volatiles with high light hydrocarbon content, improving the effectiveness of adsorption methods for treating crude oil volatiles and meeting emission standards.

[0006] To achieve the above objectives, the present invention provides an amino-modified activated carbon material, which includes activated carbon and amino groups modified on the surface of the activated carbon.

[0007] The specific surface area of ​​the amino-modified activated carbon material is 1500–2100 m². 2 / g, with a pore volume of 0.6~1.1mL / g.

[0008] Preferably, the amino-modified activated carbon material is in granular form.

[0009] Preferably, the particle size of the amino-modified activated carbon material is 1-3 mm.

[0010] Preferably, the nitrogen content is 0.3-3% by weight, based on the total weight of the amino-modified activated carbon material.

[0011] A second aspect of the present invention provides a method for preparing amino-modified activated carbon materials, the method comprising the following steps:

[0012] (1) Carbonize the carbon source to obtain a carbon precursor;

[0013] (2) The carbon precursor is mixed with an alkaline source for activation, and then treated with acid to obtain the activated carbon precursor;

[0014] (3) The surface of the activated carbon precursor is modified by using an oxidant to modify the surface of the activated carbon precursor with carboxyl and hydroxyl groups;

[0015] (4) The product obtained in step (3) is modified with an amino reagent.

[0016] Preferably, step (1) includes: carbonizing the carbon source under an inert atmosphere, then crushing and sieving to obtain a particulate carbon precursor.

[0017] Preferably, the carbon precursor has a particle size of 1–1.4 mm and a BET specific surface area of ​​100–400 m². 2 / g, with a pore volume of 0.05~0.2mL / g.

[0018] Preferably, the carbon source is selected from one or more of coconut shells, apricot shells, walnut shells, and bamboo.

[0019] Preferably, the carbonization conditions include: an inert atmosphere flow rate of 50–70 mL / min, a heating rate of 2–10 °C / min, a temperature of 400–600 °C, and a time of 30–180 min.

[0020] Preferably, in step (2), the weight ratio of the carbon precursor to the alkali source is 1:1 to 5.

[0021] Preferably, the activation conditions include: an inert atmosphere flow rate of 40–80 mL / min, a heating rate of 1–10 °C / min, an activation temperature of 500–900 °C, and an activation time of 30–120 min.

[0022] Preferably, the alkali source is one or more of KOH, K2CO3 and NaNH2.

[0023] Preferably, in step (2), the carbon precursor and the alkali source are mixed by solution impregnation or solid mixing.

[0024] Preferably, in step (2), the acid treatment process includes: adding an acidic solution dropwise to the activated product until the pH of the solution is 6.5 to 7.5, then filtering, washing, and drying to obtain granular activated carbon precursor.

[0025] Preferably, the concentration of the acidic solution is 0.5 to 1.5 mol / L.

[0026] Preferably, the acid in the acidic solution is selected from one or more of hydrochloric acid, sulfuric acid, and nitric acid.

[0027] Preferably, the activated carbon precursor has a particle size of 1–1.4 mm and a BET specific surface area of ​​1400–2500 m². 2 / g, with a pore volume of 0.5~1.4mL / g.

[0028] Preferably, in step (3), the oxidant is selected from one or more of hydrogen peroxide, concentrated sulfuric acid, concentrated nitric acid and ozone.

[0029] Preferably, when the oxidant is hydrogen peroxide, the specific method for surface modification of the activated carbon precursor using the oxidant is as follows: react the activated carbon precursor with hydrogen peroxide, and then sequentially perform solid-liquid separation, ultrasonic washing, and drying on the reaction product.

[0030] Preferably, the solid-liquid ratio of the activated carbon precursor to hydrogen peroxide is 1 g:(1-10) mL, and the concentration of hydrogen peroxide is 1-30% by weight.

[0031] Preferably, the reaction conditions include a temperature of 10–30°C and a time of 4–7 hours.

[0032] Preferably, in step (4), the amino reagent is selected from one or more of 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-ureapropyltrimethoxysilane, hexamethylenediaminemethyltrimethoxysilane, anilinemethyltrimethoxysilane, 3-aminopropyltriethoxysilane, (2-aminoisopropyl)triethoxysilane, 3-(4-ureaamino)propyltriethoxysilane, and N-aminoethyl-3-aminopropyltriethoxysilane.

[0033] Preferably, the weight ratio of the product obtained in step (3) to the amount of amino reagent is (2-40):1.

[0034] Preferably, step (4) includes: ultrasonically dispersing the product obtained in step (3), the organic solvent and the amino reagent, then reacting the obtained product in a water bath, and then sequentially performing solid-liquid separation, washing and drying on the reaction product.

[0035] Preferably, the organic solvent is selected from one or more of ethanol, ethyl acetate, methanol and chloroform.

[0036] Preferably, the solid-liquid ratio of the product obtained in step (3) to the organic solvent is 1 g: (1-3) mL.

[0037] Preferably, the ultrasonic dispersion time is 10 to 60 minutes.

[0038] Preferably, the reaction conditions include a temperature of 50–80°C and a time of 1–5 hours.

[0039] A third aspect of the present invention provides an amino-modified activated carbon material prepared by the method described above.

[0040] The fourth aspect of this invention provides an application of the amino-modified activated carbon material described above in the adsorption of light hydrocarbons.

[0041] Preferably, the light hydrocarbon is methane and / or ethane.

[0042] Compared with the prior art, the present invention has at least the following advantages:

[0043] (1) The amino-modified activated carbon material provided by the present invention is a porous material with a large pore volume and specific surface area, which can enhance its physical adsorption of light hydrocarbons and improve the light hydrocarbon adsorption capacity; at the same time, the pores of the amino-modified activated carbon material are modified with amino groups, and the interaction between the polar amino groups and the light hydrocarbon adsorbate is enhanced, resulting in high light hydrocarbon adsorption capacity and strong light hydrocarbon adsorption ability, which is beneficial to the treatment of VOCs with a high proportion of light hydrocarbons.

[0044] (2) The method of the present invention activates the carbon precursor obtained by carbonizing the carbon source and creates pores in the carbon precursor to increase the specific surface area of ​​the carbon precursor, thereby obtaining an activated carbon precursor with a large specific surface area; then, the activated carbon precursor is surface modified with an oxidant to modify hydroxyl and carboxyl groups on the surface of the activated carbon precursor, providing reaction sites for subsequent amino modification; then, the surface of the activated carbon precursor pores is modified with amino groups by chemical modification to increase the polarity of the pore surface and effectively improve the adsorption capacity of the amino-modified activated carbon material for light hydrocarbons.

[0045] (3) This invention carbonizes common carbon sources to obtain particulate carbon precursors. These particulate carbon precursors are then activated using a chemical method, resulting in granular activated carbon. This eliminates the need for granulation of powdered activated carbon, thus avoiding the blockage and loss of activated carbon pores caused by binders. Preferably, using particulate carbon precursors for activation and surface modification further improves the specific surface area and light hydrocarbon adsorption capacity of the activated carbon. Attached Figure Description

[0046] Figure 1 These are nitrogen adsorption isotherm diagrams for Examples 1, 4, 6, and Comparative Example 1;

[0047] Figure 2 These are aperture distribution diagrams for Examples 1, 4, 6, and Comparative Example 1;

[0048] Figure 3 These are ethane adsorption isotherms for Examples 1, 4, 6, and Comparative Example 1;

[0049] Figure 4 These are ethane adsorption breakthrough curves for Examples 1, 4, 6, and Comparative Example 1;

[0050] Figure 5 This is the SEM image of Example 1;

[0051] Figure 6 This is the EDS diagram of Example 1;

[0052] Figure 7 This is the thermogravimetric diagram of Example 1. Detailed Implementation

[0053] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0054] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0055] The amino-modified activated carbon material provided by this invention comprises activated carbon and amino groups modified on the surface of the activated carbon; the specific surface area of ​​the amino-modified activated carbon material is 1500-2100 m². 2 / g, with a pore volume of 0.6~1.1mL / g.

[0056] The amino-modified activated carbon material provided by this invention has a large specific surface area and the pore surface is modified with amino groups, which can effectively improve the adsorption capacity of the amino-modified activated carbon material for light hydrocarbons.

[0057] In this invention, when the ratio of activated carbon to amino groups is too high, the excess amino reagent is adsorbed into the pores of the activated carbon, affecting the pore structure of the activated carbon and causing a corresponding decrease in pore volume and specific surface area. When the ratio of activated carbon to amino groups is too low, the number of amino groups introduced to the surface of the activated carbon is small, and the effect on improving the adsorption of ethane is not obvious. Therefore, in a preferred embodiment, the nitrogen content can be 0.3 to 3% by weight, based on the total weight of the amino-modified activated carbon material.

[0058] In a preferred embodiment, the amino-modified activated carbon material is granular. Traditional activated granular carbon is obtained by mixing a binder with powdered carbon and then granulating. The binder can damage the pore structure of the activated carbon, resulting in a 30-50% loss in specific surface area after granulation. By activating the granular carbon precursor, granular carbon can be obtained without using a binder, avoiding damage to the pore structure during granulation, and can be directly filled into an adsorption tank for use. In some embodiments, the particle size of the amino-modified activated carbon material can be 1-3 mm.

[0059] The amino-modified activated carbon provided by this invention features a large specific surface area, minimal loss of pore structure before and after modification, high adsorption capacity for light hydrocarbons, strong adsorption ability for light hydrocarbons, adjustable particle size, and high particle strength, making it suitable for VOCs treatment applications with a high proportion of light hydrocarbons. Furthermore, the particle size can be adjusted by using sieves of different pore sizes before preparation, as needed.

[0060] The method for preparing amino-modified activated carbon materials provided by this invention includes the following steps:

[0061] (1) Carbonize the carbon source to obtain a carbon precursor;

[0062] (2) The carbon precursor is mixed with an alkaline source for activation, and then treated with acid to obtain the activated carbon precursor;

[0063] (3) The surface of the activated carbon precursor is modified by using an oxidant to modify the surface of the activated carbon precursor with carboxyl and hydroxyl groups;

[0064] (4) The product obtained in step (3) is modified with an amino reagent.

[0065] The method described in this invention involves obtaining a carbon precursor through carbonization, followed by activation to obtain an activated carbon precursor with a centrally located pore structure and a large specific surface area. Subsequently, the activated carbon precursor is oxidized to provide reaction sites for subsequent chemical modification. Finally, the surface of the activated carbon precursor pores is modified with amino groups via chemical modification to obtain surface-modified activated carbon, which exhibits significantly improved ethane static adsorption performance. During the oxidation and amino modification processes, the pore structure of the activated carbon remains largely unchanged, and the specific surface area is not significantly reduced.

[0066] In this invention, the carbon precursor obtained by carbonization is sequentially activated, oxidized and modified with amino groups, resulting in amino-modified activated carbon with a larger surface area, which is used for efficient adsorption of light hydrocarbons.

[0067] In one embodiment, step (1) includes: carbonizing the carbon source in an inert atmosphere, then crushing and sieving it to obtain a particulate carbon precursor.

[0068] In this invention, the carbon source is not limited and can be any carbon source commonly found in the art. In some embodiments, the carbon source is selected from one or more of coconut shells, apricot shells, walnut shells, and bamboo.

[0069] In some embodiments, the BET specific surface area of ​​the carbon precursor obtained by carbonization can be 100–400 m². 2 / g, with a pore volume of 0.05–0.2 mL / g. In this invention, the particle size of the carbon precursor can be controlled by crushing and sieving.

[0070] In a preferred embodiment, to ensure the stability of the pore structure of the final prepared amino-modified activated carbon material, the particle size of the carbon precursor cannot be too large. Specifically, the particle size of the carbon precursor obtained through carbonization can be 1–1.4 mm. In this invention, the particle size of the carbon precursor does not change significantly after activation, oxidation modification, and amino modification.

[0071] In some embodiments, the flow rate of the inert atmosphere during the carbonization process can be 50-70 mL / min, the heating rate can be 2-10 °C / min, the temperature can be 400-600 °C, and the time can be 30-180 min.

[0072] In this invention, the carbon precursor is activated by an alkaline source, which can increase its pore structure and improve its specific surface area.

[0073] In the method described in this invention, the carbon precursor can be activated by mixing the carbon precursor with an alkaline source using either solution impregnation or solid-state mixing. In a preferred embodiment, to further increase the specific surface area of ​​the obtained activated carbon precursor, the carbon precursor is activated by mixing the carbon precursor with an alkaline source using solution impregnation.

[0074] In one embodiment, the process of activating the carbon precursor by mixing it with an alkaline source using a solution impregnation method includes: mixing the alkaline source solution and the carbon precursor, then dispersing them ultrasonically, followed by drying; then placing the resulting product in a magnetic boat and activating it at high temperature in a tube furnace. In a more preferred embodiment, the molar concentration of the alkaline source solution is 20–60 mol / L. In a more preferred embodiment, the ultrasonic dispersion time is 5–30 min. In a more preferred embodiment, the drying conditions include a temperature of 110–130°C and a time of 1–4 h.

[0075] In another embodiment, the process of activating the carbon precursor by mixing the carbon precursor with the alkali source using solid-state mixing includes: mixing the alkali source and the carbon precursor and placing them in a magnetic boat, then placing them in a tube furnace for high-temperature activation.

[0076] In this invention, the alkali source used for activation can be a conventional choice in the art. In some embodiments, the alkali source can be one or more of KOH, K2CO3, and NaNH2.

[0077] In some embodiments, the weight ratio of the carbon precursor to the alkali source in step (2) can be 1:1 to 5, for example, 1:1, 1:2, 1:3, 1:4 or 1:5.

[0078] In this invention, in order to improve the activation effect and increase the specific surface area of ​​the prepared modified activated carbon, in a preferred embodiment, the flow rate of the activation inert atmosphere can be 40-80 mL / min, the heating rate can be 1-10 °C / min, the activation temperature can be 500-900 °C, and the activation time can be 30-120 min.

[0079] In this invention, the purpose of acid treatment is to neutralize the alkali remaining in the activated carbon during activation. In one embodiment, step (2) of acid treatment includes: adding an acidic solution dropwise to the activated product until the pH of the solution is 6.5–7.5, then filtering, washing, and drying to obtain granular activated carbon precursor. In a preferred embodiment, the concentration of the acidic solution can be 0.5–1.5 mol / L. In a more preferred embodiment, the acid in the acidic solution can be selected from one or more of hydrochloric acid, sulfuric acid, and nitric acid.

[0080] In this invention, the activated carbon precursor, after activation and acid treatment, exhibits a significantly increased pore structure and a markedly improved specific surface area. In some embodiments, the BET specific surface area of ​​the activated carbon precursor can be 1400–2500 m². 2 / g, and the pore volume can be 0.5~1.4mL / g.

[0081] In some embodiments, the particle size of the activated carbon precursor can be 1 to 1.4 mm.

[0082] In this invention, the purpose of step (3) is to modify the surface of the activated carbon precursor, thereby facilitating subsequent amino modification.

[0083] In this invention, the oxidant can be any conventionally chosen agent in the art. In some embodiments, the oxidant can be selected from one or more of hydrogen peroxide, concentrated sulfuric acid, concentrated nitric acid, and ozone. In a preferred embodiment, the oxidant is hydrogen peroxide and / or concentrated nitric acid, more preferably hydrogen peroxide.

[0084] When activated carbon is treated with an oxidant, carboxyl and hydroxyl groups can be modified on the surface of the activated carbon. In one embodiment, when hydrogen peroxide is used as the oxidant, the specific method for surface modification of the activated carbon precursor with the oxidant is as follows: the activated carbon precursor is reacted with hydrogen peroxide, and then the reaction product is subjected to solid-liquid separation, ultrasonic washing, and drying in sequence. In a preferred embodiment, the solid-liquid ratio of the activated carbon precursor to hydrogen peroxide can be 1 g:(1-10) mL, and the concentration of hydrogen peroxide can be 1-30% by weight. In another preferred embodiment, the reaction temperature can be 10-30°C, and the reaction time can be 4-7 h.

[0085] In this invention, the purpose of step (4) is to modify the surface of activated carbon with amino groups.

[0086] In a preferred embodiment, the amino reagent used for amino modification can be a silane-based amino reagent commonly used in the art. Specifically, in step (4), the amino reagent is selected from one or more of 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-ureapropyltrimethoxysilane, hexamethylenediaminemethyltrimethoxysilane, anilinemethyltrimethoxysilane, 3-aminopropyltriethoxysilane, (2-aminoisopropyl)triethoxysilane, 3-(4-ureaamino)propyltriethoxysilane, and N-aminoethyl-3-aminopropyltriethoxysilane.

[0087] In this invention, in order to modify activated carbon with appropriate amino groups and further improve the static adsorption performance of modified activated carbon for ethane, it is necessary to appropriately control the amount of amino reagent. In a preferred embodiment, the weight ratio of the product obtained in step (3) to the amount of amino reagent can be (2-40):1.

[0088] In this invention, step (4) specifically includes: ultrasonically dispersing the product obtained in step (3), the organic solvent and the amino reagent, then reacting the obtained product in a water bath, and then sequentially performing solid-liquid separation, washing and drying on the reaction product.

[0089] In this invention, the organic solvent can be any conventional choice in the art, as long as it can disperse the product and amino reagent obtained in step (3). In a preferred embodiment, the organic solvent in step (4) can be selected from one or more of ethanol, ethyl acetate, methanol, and chloroform.

[0090] In some embodiments, the solid-liquid ratio of the product obtained in step (3) to the organic solvent can be 1 g: (1-3) mL.

[0091] In some embodiments, the ultrasonic dispersion time in step (4) can be 10 to 60 minutes.

[0092] In order to modify the product obtained in step (3) with amino groups, in a preferred embodiment, the reaction in step (4) is carried out at a temperature of 50 to 80°C for a time of 1 to 5 hours.

[0093] The method described in this invention can activate particulate carbon precursors using chemical methods to obtain granular activated carbon, which eliminates the need for granulation and molding processes, thereby avoiding the blockage and loss of activated carbon pore structure by binders. On the other hand, by modifying the surface of carbon material pores with amine groups through chemical modification, the polarity of the pore surface can be increased, which can effectively improve the adsorption capacity of activated carbon for ethane.

[0094] The amino-modified activated carbon material prepared by the method described above, provided by this invention, has a large specific surface area.

[0095] In some embodiments, the amino-modified activated carbon material comprises activated carbon and amino groups modified on the surface of the activated carbon; the specific surface area of ​​the amino-modified activated carbon material is 1500–2100 m². 2 / g, with a pore volume of 0.6-1.1mL / g.

[0096] In some embodiments, the amino-modified activated carbon material may be in granular form.

[0097] In some embodiments, the particle size of the amino-modified activated carbon material can be 1–3 mm.

[0098] In some embodiments, the nitrogen content is 0.3 to 3% by weight, based on the total weight of the amino-modified activated carbon material.

[0099] This invention also provides an application of the aforementioned amino-modified activated carbon material in the adsorption of light hydrocarbons. In a preferred embodiment, the amino-modified activated carbon material can be used to adsorb methane and / or ethane.

[0100] The amino-modified activated carbon material provided by this invention has a high adsorption capacity for ethane and is suitable for application in the field of adsorption and recovery of crude oil volatiles with high light hydrocarbon content, thereby improving the effect of adsorption method for treating crude oil volatiles and meeting the requirements for emission standards.

[0101] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto. Unless otherwise specified, the raw materials used in the following embodiments are all common commercially available products.

[0102] In the following examples, potassium hydroxide, 30% hydrogen peroxide, ethanol, and ethyl acetate were purchased from Sinopharm Chemical Reagent Co., Ltd.; 3-aminopropyltrimethoxysilane, anilinemethyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane were purchased from Shanghai Maclean Biochemical Technology Co., Ltd.; and coconut shells were sourced from Indonesia.

[0103] In the following examples, the specific surface area, pore volume, and pore size of the samples were determined using a BSD-PM2 surface area analyzer from Best Instruments Technology (Beijing) Co., Ltd. Approximately 100 mg of sample was weighed, degassed under vacuum at 300°C for 6 hours, and then molecularly tested using nitrogen as a probe at liquid nitrogen temperature (-196°C) to obtain the corresponding data. Specific surface area (S...) BETThe Brunauer-Emmet-Teller (BET) equation was used for calculations, with relative pressures (p / p0) ranging from 0.01 to 0.15, requiring a correlation coefficient greater than 0.999 and a C value greater than 0. The total pore volume was derived from the N2 adsorption amount at a relative pressure of 0.99. The pore size distribution was obtained using nonlocal density function theory (NLDFT).

[0104] In the following examples, the nitrogen content in the sample was determined using an Elementar Unicube elemental analyzer. Specifically, approximately 10 mg of sample was weighed, placed in the sample chamber, and the CHN mode was selected to analyze the elemental composition of the sample.

[0105] Example 1

[0106] Step 1: Carbonization Process. Using coconut shells as a precursor, the coconut shells were placed in a magnetic boat within a flowing argon atmosphere and then placed in a tube furnace for carbonization. The carbonization conditions included: argon flow rate of 60 mL / min, heating rate of 5℃ / min, temperature of 500℃, and time of 60 min. The carbonized coconut shells were then crushed, and the particles were sieved using 14-mesh and 18-mesh sieves to obtain carbon precursor particles with a size of 1.0–1.4 mm and a BET specific surface area of ​​220 m². 2 / g, pore volume is 0.11mL / g.

[0107] Step 2: Activation Process. Weigh 5g of granular carbon precursor and 20g of powdered KOH to prepare a 40mol / L potassium hydroxide solution. Mix the granular carbon precursor and potassium hydroxide solution, then ultrasonically disperse for 15min. Dry at 120℃, and place the dried product in a magnetic boat in a tube furnace for high-temperature activation. The activation conditions are: argon flow rate of 60mL / min, heating rate of 5℃ / min, temperature of 800℃, and time of 120min. After activation, allow to cool to room temperature, remove the activated product from the tube furnace and place it in a beaker. Add 1mol / L hydrochloric acid solution dropwise until the solution is neutral. Filter to obtain solid particles, wash three times with deionized water, and dry in an 80℃ oven for 6h to obtain granular activated carbon precursor with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1943m². 2 / g, pore volume is 0.91mL / g.

[0108] Step 3: Surface oxidation modification of the granular activated carbon precursor. This is performed as follows: ① Weigh 3g of the granular activated carbon precursor into a beaker, then add 15mL of 10% hydrogen peroxide. React at 200r / min and room temperature (25℃) for 4 hours to obtain a granular activated carbon suspension; ② Filter the suspension to remove the liquid phase, obtaining the solid phase; ③ Mix the solid phase with deionized water, wash under ultrasonic conditions for 20 minutes, filter to obtain the solid phase, repeat the washing process three times, and air-dry in a ventilated area for 15 hours; ④ Place the solid phase in a vacuum oven and dry at 100℃ for 6 hours under an absolute pressure of 10kPa to obtain oxidized modified granular activated carbon with a particle size of 1.0–1.4mm and a BET specific surface area of ​​2131m². 2 / g, pore volume 0.98mL / g.

[0109] Step 4: Amine modification of the pore surface. This is performed as follows: ① Add 3g of oxidized modified granular activated carbon to a beaker, add 10mL of ethanol, then add 0.3g of 3-aminopropyltrimethoxysilane. Disperse ultrasonically for 20min to obtain a granular activated carbon suspension; ② Place the suspension in a 70℃ water bath and react for 3h with a stirring speed of 200r / min; ③ After the reaction, filter to remove the liquid phase, obtaining granular activated carbon. Rinse with ethanol and air-dry in a ventilated area for 16h; ④ Place the activated carbon in a vacuum oven and dry at 80℃ under an absolute pressure of 10kPa for 10h to obtain granular activated carbon with an amino-modified pore surface and a particle size of 1.0–1.4mm. The BET specific surface area of ​​the granular activated carbon is 1952m². 2 / g, with a pore volume of 0.92mL / g, and ethane adsorption performance is shown in Table 1.

[0110] Elemental analysis using an Elementa Unicube instrument revealed that the nitrogen content in the amino-modified activated carbon material prepared in this embodiment was 2.42% by mass.

[0111] The microstructure and EDS spectra of the amino-modified activated carbon were analyzed using a JMC7000 scanning electron microscope (JEOL Ltd.). Figure 5 SEM image and Figure 6 The EDS image shows that the material surface has many honeycomb pores, and the main elements on the carbon surface are C, O, N, and Si, with N being relatively evenly distributed. Figure 7 The thermogravimetric analysis shows that the mass of activated carbon decreases as the temperature increases, indicating that the amino reagents introduced onto the surface of the carbon material decompose under high temperature conditions.

[0112] Example 2

[0113] Step 1: Carbonization Process. Using coconut shells as a precursor, the coconut shells were placed in a magnetic boat within a flowing argon atmosphere and then placed in a tube furnace for carbonization. The carbonization conditions included: argon flow rate of 60 mL / min, heating rate of 5℃ / min, temperature of 500℃, and time of 60 min. The carbonized coconut shells were then crushed, and the particles were sieved using 14-mesh and 18-mesh sieves to obtain carbon precursor particles with a size of 1.0–1.4 mm and a BET specific surface area of ​​220 m². 2 / g, pore volume is 0.11mL / g.

[0114] Step 2: Activation Process. Weigh 5g of granular carbon precursor and 25g of powdered KOH to prepare a 40mol / L potassium hydroxide solution. Mix the granular carbon precursor and potassium hydroxide solution, then ultrasonically disperse for 15min. Dry at 120℃, and place the dried product in a magnetic boat in a tube furnace for high-temperature activation. The activation conditions are: argon flow rate of 60mL / min, heating rate of 5℃ / min, temperature of 800℃, and time of 120min. After activation, allow to cool to room temperature, remove the activated product from the tube furnace and place it in a beaker. Add 1mol / L hydrochloric acid solution dropwise until the solution is neutral. Filter to obtain solid particles, wash three times with deionized water, and dry in an 80℃ oven for 6h to obtain granular activated carbon precursor with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1799m². 2 / g, pore volume is 0.88mL / g.

[0115] Step 3: Surface oxidation modification of the granular activated carbon precursor. This is performed as follows: ① Weigh 3g of the granular activated carbon precursor into a beaker, then add 15mL of 30% hydrogen peroxide. React at 200r / min and room temperature (25℃) for 4 hours to obtain a granular activated carbon suspension; ② Filter the suspension to remove the liquid phase, obtaining the solid phase; ③ Mix the solid phase with deionized water, wash under ultrasonic conditions for 20 minutes, filter to obtain the solid product, repeat the washing process three times, and air-dry in a ventilated area for 15 hours; ④ Place the solid product in a vacuum oven and dry at 100℃ for 6 hours under an absolute pressure of 10kPa to obtain oxidized modified granular activated carbon with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1642m². 2 / g, pore volume is 0.78mL / g.

[0116] Step 4: Amine modification of the pore surface. This is performed as follows: ① Add 3g of oxidized modified granular activated carbon to a beaker, add 10mL of ethanol, then add 0.3g of 3-aminopropyltrimethoxysilane. Disperse ultrasonically for 20min to obtain a granular activated carbon suspension; ② Place the suspension in a 70℃ water bath and react for 3h with a stirring speed of 200r / min; ③ After the reaction, filter to remove the liquid phase, obtaining granular activated carbon. Rinse with ethanol and air-dry in a ventilated area for 16h; ④ Place the activated carbon in a vacuum oven and dry at 80℃ under an absolute pressure of 10kPa for 10h to obtain granular activated carbon with an amino-modified pore surface and a particle size of 1.0–1.4mm. The BET specific surface area of ​​the granular activated carbon is 1631m². 2 / g, with a pore volume of 0.74mL / g, and ethane adsorption performance is shown in Table 1.

[0117] Analysis using an Elementa Unicube elemental analyzer revealed that the nitrogen content in the amino-modified activated carbon material prepared in this embodiment was 1.57% by mass.

[0118] Example 3

[0119] Step 1: Carbonization Process. Using coconut shells as a precursor, the coconut shells were placed in a magnetic boat within a flowing argon atmosphere and then placed in a tube furnace for carbonization. The carbonization conditions included: argon flow rate of 60 mL / min, heating rate of 5℃ / min, temperature of 500℃, and time of 60 min. The carbonized coconut shells were then crushed, and the particles were sieved using 14-mesh and 18-mesh sieves to obtain carbon precursor particles with a size of 1.0–1.4 mm and a BET specific surface area of ​​220 m². 2 / g, pore volume is 0.11mL / g.

[0120] Step 2: Activation Process. Weigh 5g of granular carbon precursor and 20g of powdered KOH to prepare a 40mol / L potassium hydroxide solution. Mix the granular carbon precursor and potassium hydroxide solution, then ultrasonically disperse for 15min. Dry at 120℃, and place the dried product in a magnetic boat in a tube furnace for high-temperature activation. The activation conditions are: argon flow rate of 60mL / min, heating rate of 5℃ / min, temperature of 900℃, and time of 120min. After activation, allow to cool to room temperature, remove the activated product from the tube furnace and place it in a beaker. Add 1mol / L hydrochloric acid solution dropwise until the solution is neutral. Filter to obtain solid particles, wash three times with deionized water, and dry in an 80℃ oven for 6h to obtain granular activated carbon precursor with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1880m². 2 / g, pore volume is 0.81mL / g.

[0121] Step 3: Surface oxidation modification of the granular activated carbon precursor. This is performed as follows: ① Weigh 3g of the granular activated carbon precursor into a beaker, then add 15mL of 20% hydrogen peroxide. React at 200r / min and room temperature (25℃) for 4 hours to obtain a granular activated carbon suspension; ② Filter the suspension to remove the liquid phase, obtaining the solid phase; ③ Mix the solid phase with deionized water, wash under ultrasonic conditions for 20 minutes, filter to obtain the solid phase, repeat the washing process three times, and air-dry in a ventilated area for 15 hours; ④ Place the solid phase in a vacuum oven and dry at 100℃ for 6 hours under an absolute pressure of 10kPa to obtain oxidized modified granular activated carbon with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1936m². 2 / g, pore volume is 0.87mL / g.

[0122] Step 4: Amine modification of the pore surface. This is performed as follows: ① Add 3g of oxidized modified granular activated carbon to a beaker, add 10mL of ethanol, then add 0.6g of 3-aminopropyltrimethoxysilane. Disperse ultrasonically for 20min to obtain a granular activated carbon suspension; ② Place the suspension in a 70℃ water bath and react for 3h with a stirring speed of 200r / min; ③ After the reaction, filter to remove the liquid phase, obtaining granular activated carbon. Rinse with ethanol and air-dry in a ventilated area for 16h; ④ Place the activated carbon in a vacuum oven and dry at 80℃ under an absolute pressure of 10kPa for 10h to obtain granular activated carbon with an amino-modified pore surface and a particle size of 1.0–1.4mm. The BET specific surface area of ​​the granular activated carbon is 1842m². 2 / g, with a pore volume of 0.78mL / g, and ethane adsorption performance is shown in Table 1.

[0123] Elemental analysis using an Elementa Unicube instrument revealed that the nitrogen content in the amino-modified activated carbon material prepared in this embodiment was 1.48% by mass.

[0124] Example 4

[0125] Step 1: Carbonization Process. Using coconut shells as a precursor, the coconut shells were placed in a magnetic boat within a flowing argon atmosphere and then placed in a tube furnace for carbonization. The carbonization conditions included: argon flow rate of 60 mL / min, heating rate of 5℃ / min, temperature of 500℃, and time of 60 min. The carbonized coconut shells were then crushed, and the particles were sieved using 14-mesh and 18-mesh sieves to obtain carbon precursor particles with a size of 1.0–1.4 mm and a BET specific surface area of ​​220 m². 2 / g, pore volume is 0.11mL / g.

[0126] Step 2: Activation Process. Weigh 5g of granular carbon precursor and 20g of powdered KOH to prepare a 40mol / L potassium hydroxide solution. Mix the granular carbon precursor and potassium hydroxide solution, then ultrasonically disperse for 15min. Dry at 120℃, and place the dried product in a magnetic boat in a tube furnace for high-temperature activation. The activation conditions are: argon flow rate of 60mL / min, heating rate of 5℃ / min, temperature of 800℃, and time of 120min. After activation, allow to cool to room temperature, remove the activated product from the tube furnace and place it in a beaker. Add 1mol / L hydrochloric acid solution dropwise until the solution is neutral. Filter to obtain solid particles, wash three times with deionized water, and dry in an 80℃ oven for 6h to obtain granular activated carbon precursor with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1943m². 2 / g, pore volume is 0.91mL / g.

[0127] Step 3: Surface oxidation modification of the granular activated carbon precursor. This is performed as follows: ① Weigh 3g of the granular activated carbon precursor into a beaker, then add 15mL of 10% hydrogen peroxide. React at 200r / min and room temperature (25℃) for 4 hours to obtain a granular activated carbon suspension; ② Filter the suspension to remove the liquid phase, obtaining the solid phase; ③ Mix the solid phase with deionized water, wash under ultrasonic conditions for 20 minutes, filter to obtain the solid product, repeat the washing process three times, and air-dry in a ventilated area for 15 hours; ④ Place the solid product in a vacuum oven and dry at 100℃ for 6 hours under an absolute pressure of 10kPa to obtain oxidation-modified granular activated carbon with a particle size of 1.0–1.4mm and a BET specific surface area of ​​2131m². 2 / g, pore volume is 0.98mL / g.

[0128] Step 4: Amine modification of the pore surface. This is performed as follows: ① Add 3g of oxidized modified granular activated carbon to a beaker, add 10mL of ethanol, then add 0.9g of 3-aminopropyltrimethoxysilane. Disperse ultrasonically for 20min to obtain a granular activated carbon suspension; ② Place the suspension in a 70℃ water bath and react for 3h with a stirring speed of 200r / min; ③ After the reaction, filter to remove the liquid phase, obtaining granular activated carbon. Rinse with ethanol and air-dry in a ventilated area for 16h; ④ Place the activated carbon in a vacuum oven and dry at 80℃ under an absolute pressure of 10kPa for 10h to obtain granular activated carbon with an amino-modified pore surface and a particle size of 1.0–1.4mm. The BET specific surface area of ​​the granular activated carbon is 1702m². 2 / g, with a pore volume of 0.82mL / g, and ethane adsorption performance is shown in Table 1.

[0129] Elemental analysis using an Elementa Unicube instrument revealed that the nitrogen content in the amino-modified activated carbon material prepared in this embodiment was 1.93% by mass.

[0130] Example 5

[0131] Step 1: Carbonization Process. Using coconut shells as a precursor, the coconut shells were placed in a magnetic boat within a flowing argon atmosphere and then placed in a tube furnace for carbonization. The carbonization conditions included: argon flow rate of 60 mL / min, heating rate of 5℃ / min, temperature of 500℃, and time of 60 min. The carbonized coconut shells were then crushed, and the particles were sieved using 14-mesh and 18-mesh sieves to obtain carbon precursor particles with a size of 1.0–1.4 mm and a BET specific surface area of ​​220 m². 2 / g, pore volume is 0.11mL / g.

[0132] Step 2: Activation Process. Weigh 5g of granular carbon precursor and 20g of powdered KOH to prepare a 40mol / L potassium hydroxide solution. Mix the granular carbon precursor and potassium hydroxide solution, then ultrasonically disperse for 15min. Dry at 120℃, and place the dried product in a magnetic boat in a tube furnace for high-temperature activation. The activation conditions are: argon flow rate of 60mL / min, heating rate of 5℃ / min, temperature of 900℃, and time of 120min. After activation, allow to cool to room temperature, remove the activated product from the tube furnace and place it in a beaker. Add 1mol / L hydrochloric acid solution dropwise until the solution is neutral. Filter to obtain solid particles, wash three times with deionized water, and dry in an 80℃ oven for 6h to obtain granular activated carbon precursor with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1880m². 2 / g, pore volume is 0.81mL / g.

[0133] Step 3: Surface oxidation modification of the granular activated carbon precursor. This is performed as follows: ① Weigh 3g of the granular activated carbon precursor into a beaker, then add 15mL of 20% hydrogen peroxide. React at 200r / min and room temperature (25℃) for 4 hours to obtain a granular activated carbon suspension; ② Filter the suspension to remove the liquid phase, obtaining the solid portion; ③ Mix the solid portion with deionized water, wash under ultrasonic conditions for 20 minutes, filter to obtain the solid product, repeat the washing process three times, and air-dry in a ventilated area for 15 hours; ④ Place the solid product in a vacuum oven and dry at 100℃ for 6 hours under an absolute pressure of 10kPa to obtain oxidized modified granular activated carbon with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1936m². 2 / g, pore volume is 0.87mL / g.

[0134] Step 4: Amine modification of the pore surface. This is performed as follows: ① Add 3g of oxidized modified granular activated carbon to a beaker, add 10mL of ethanol, then add 0.3g of aniline methyltrimethoxysilane. Disperse ultrasonically for 20min to obtain a granular activated carbon suspension; ② Place the suspension in a 70℃ water bath and react for 3h with a stirring speed of 200r / min; ③ After the reaction, filter to remove the liquid phase, obtaining granular activated carbon. Rinse with ethanol and air-dry in a ventilated area for 16h; ④ Place the activated carbon in a vacuum oven and dry at 80℃ under an absolute pressure of 10kPa for 10h to obtain granular activated carbon with an amino-modified pore surface and a particle size of 1.0–1.4mm. The BET specific surface area of ​​the granular activated carbon is 1682m². 2 / g, with a pore volume of 0.68mL / g, and ethane adsorption performance is shown in Table 1.

[0135] Analysis using an Elementa Unicube elemental analyzer revealed that the nitrogen content in the amino-modified activated carbon material prepared in this embodiment was 1.36% by mass.

[0136] Example 6

[0137] Step 1: Carbonization Process. Using coconut shells as a precursor, the coconut shells were placed in a magnetic boat within a flowing argon atmosphere and then placed in a tube furnace for carbonization. The carbonization conditions included: argon flow rate of 60 mL / min, heating rate of 5℃ / min, temperature of 500℃, and time of 60 min. The carbonized coconut shells were then crushed, and the particles were sieved using 14-mesh and 18-mesh sieves to obtain carbon precursor particles with a size of 1.0–1.4 mm and a BET specific surface area of ​​220 m². 2 / g, pore volume is 0.11mL / g.

[0138] Step 2: Activation Process. Weigh 5g of granular carbon precursor and 20g of powdered KOH. Mix them using a solid-state mixing method, place them in a magnetic boat, mix thoroughly, and then place the boat in a tube furnace for high-temperature activation in a flowing argon atmosphere. The activation conditions are: argon flow rate of 60mL / min, heating rate of 5℃ / min, temperature of 800℃, and time of 120min. After activation, allow the mixture to cool to room temperature, remove the activated product from the tube furnace, place it in a beaker, and add 1mol / L hydrochloric acid solution dropwise until the solution is neutral. Filter to obtain solid particles, wash three times with deionized water, and dry in an 80℃ oven for 6 hours to obtain granular activated carbon precursor with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1732m². 2 / g, pore volume is 0.65mL / g.

[0139] Step 3: Surface oxidation modification of the granular activated carbon precursor. This is performed as follows: ① Weigh 3g of the granular activated carbon precursor into a beaker, then add 15mL of 5% hydrogen peroxide. React at 200r / min and room temperature (25℃) for 4 hours to obtain a granular activated carbon suspension; ② Filter the suspension to remove the liquid phase, obtaining the solid portion; ③ Mix the solid portion with deionized water, wash under ultrasonic conditions for 20 minutes, filter to obtain the solid product, repeat the washing process three times, and air-dry in a ventilated area for 15 hours; ④ Place the solid product in a vacuum oven and dry at 100℃ for 6 hours under an absolute pressure of 10kPa to obtain oxidation-modified granular activated carbon with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1768m². 2 / g, pore volume is 0.68mL / g.

[0140] Step 4: Amine modification of the pore surface. This is performed as follows: ① Add 3g of oxidized modified granular activated carbon to a beaker, add 10mL of ethanol, then add 0.3g of 3-aminopropyltrimethoxysilane. Disperse ultrasonically for 20min to obtain a granular activated carbon suspension; ② Place the suspension in a 70℃ water bath and react for 3h with a stirring speed of 200r / min; ③ After the reaction, filter to remove the liquid phase, obtaining granular activated carbon. Rinse with ethanol and air-dry in a ventilated area for 16h; ④ Place the activated carbon in a vacuum oven and dry at 80℃ under an absolute pressure of 10kPa for 10h to obtain granular activated carbon with an amino-modified pore surface and a particle size of 1.0–1.4mm. The BET specific surface area of ​​the granular activated carbon is 1708m². 2 / g, pore volume 0.62mL / g, ethane adsorption performance is shown in Table 1.

[0141] Elemental analysis using an Elementa Unicube instrument revealed that the nitrogen content in the amino-modified activated carbon material prepared in this embodiment was 1.48% by mass.

[0142] Example 7

[0143] Step 1: Carbonization Process. Using coconut shells as a precursor, the coconut shells were placed in a magnetic boat within a flowing argon atmosphere and then placed in a tube furnace for carbonization. The carbonization conditions included: argon flow rate of 60 mL / min, heating rate of 5℃ / min, temperature of 500℃, and time of 60 min. The carbonized coconut shells were then crushed, and the particles were sieved using 14-mesh and 18-mesh sieves to obtain carbon precursor particles with a size of 1.0–1.4 mm and a BET specific surface area of ​​220 m². 2 / g, pore volume is 0.11mL / g.

[0144] Step 2: Activation Process. Weigh 5g of granular carbon precursor and 15g of powdered KOH to prepare a 40mol / L potassium hydroxide solution. Mix the granular carbon precursor and potassium hydroxide solution, then ultrasonically disperse for 15min. Dry at 120℃, and place the dried product in a magnetic boat in a tube furnace for high-temperature activation. The activation conditions are: argon flow rate of 60mL / min, heating rate of 5℃ / min, temperature of 800℃, and time of 120min. After activation, allow to cool to room temperature, remove the activated product from the tube furnace and place it in a beaker. Add 1mol / L hydrochloric acid solution dropwise until the solution is neutral. Filter to obtain solid particles, wash three times with deionized water, and dry in an 80℃ oven for 6h to obtain granular activated carbon precursor with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1668m². 2 / g, pore volume is 0.75mL / g.

[0145] Step 3: Surface oxidation modification of the granular activated carbon precursor. This is performed as follows: ① Weigh 3g of the granular activated carbon precursor into a beaker, then add 15mL of 10% hydrogen peroxide. React at 200r / min and room temperature (25℃) for 4 hours to obtain a granular activated carbon suspension; ② Filter the suspension to remove the liquid phase, obtaining the solid phase; ③ Mix the solid phase with deionized water, wash under ultrasonic conditions for 20 minutes, filter to obtain the solid product, repeat the washing process three times, and air-dry in a ventilated area for 15 hours; ④ Place the solid product in a vacuum oven and dry at 100℃ for 6 hours under an absolute pressure of 10kPa to obtain oxidized modified granular activated carbon with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1755m². 2 / g, pore volume is 0.81mL / g.

[0146] Step 4: Amine modification of the pore surface. This is performed as follows: ① Add 3g of oxidized modified granular activated carbon to a beaker, add 10mL of ethanol, then add 0.6g of 3-aminopropyltrimethoxysilane. Disperse ultrasonically for 20min to obtain a granular activated carbon suspension; ② Place the suspension in a 70℃ water bath and react for 3h with a stirring speed of 200r / min; ③ After the reaction, filter to remove the liquid phase, obtaining granular activated carbon. Rinse with ethanol and air-dry in a ventilated area for 16h; ④ Place the activated carbon in a vacuum oven and dry at 80℃ under an absolute pressure of 10kPa for 10h to obtain granular activated carbon with an amino-modified pore surface and a particle size of 1.0–1.4mm. The BET specific surface area of ​​the granular activated carbon is 1688m². 2 / g, with a pore volume of 0.68mL / g, and ethane adsorption performance is shown in Table 1.

[0147] Elemental analysis using an Elementa Unicube instrument revealed that the nitrogen content in the amino-modified activated carbon material prepared in this embodiment was 1.83% by mass.

[0148] Example 8

[0149] Step 1: Carbonization Process. Using coconut shells as a precursor, the coconut shells were placed in a magnetic boat within a flowing argon atmosphere and then placed in a tube furnace for carbonization. The carbonization conditions included: argon flow rate of 60 mL / min, heating rate of 5℃ / min, temperature of 500℃, and time of 60 min. The carbonized coconut shells were then crushed, and the particles were sieved using 14-mesh and 18-mesh sieves to obtain carbon precursor particles with a size of 1.0–1.4 mm and a BET specific surface area of ​​220 m². 2 / g, pore volume is 0.11mL / g.

[0150] Step 2: Activation Process. Weigh 5g of granular carbon precursor and 20g of powdered KOH to prepare a 40mol / L potassium hydroxide solution. Mix the granular carbon precursor and potassium hydroxide solution, then ultrasonically disperse for 15min. Dry at 120℃, and place the dried product in a magnetic boat in a tube furnace for high-temperature activation. The activation conditions are: argon flow rate of 60mL / min, heating rate of 5℃ / min, temperature of 800℃, and time of 120min. After activation, allow to cool to room temperature, remove the activated product from the tube furnace and place it in a beaker. Add 1mol / L hydrochloric acid solution dropwise until the solution is neutral. Filter to obtain solid particles, wash three times with deionized water, and dry in an 80℃ oven for 6h to obtain granular activated carbon precursor with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1943m². 2 / g, pore volume is 0.91mL / g.

[0151] Step 3: Surface oxidation modification of the granular activated carbon precursor. This is performed as follows: ① Weigh 3g of the granular activated carbon precursor into a beaker, then add 15mL of 30% hydrogen peroxide. React at 200r / min and room temperature (25℃) for 4 hours to obtain a granular activated carbon suspension; ② Filter the suspension to remove the liquid phase, obtaining the solid phase; ③ Mix the solid phase with deionized water, wash under ultrasonic conditions for 20 minutes, filter to obtain the solid product, repeat the washing process three times, and air-dry in a ventilated area for 15 hours; ④ Place the solid product in a vacuum oven and dry at 100℃ for 6 hours under an absolute pressure of 10kPa to obtain oxidized modified granular activated carbon with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1842m². 2 / g, pore volume is 0.82mL / g.

[0152] Step 4: Amine modification of the pore surface. This is performed as follows: ① Add 3g of oxidized modified granular activated carbon to a beaker, add 10mL of ethanol, then add 0.6g of aniline methyltrimethoxysilane. Disperse ultrasonically for 20min to obtain a granular activated carbon suspension; ② Place the suspension in a 70℃ water bath and react for 3h with a stirring speed of 200r / min; ③ After the reaction, filter to remove the liquid phase, obtaining granular activated carbon. Rinse with ethanol and air-dry in a ventilated area for 16h; ④ Place the activated carbon in a vacuum oven and dry at 80℃ under an absolute pressure of 10kPa for 10h to obtain granular activated carbon with an amino-modified pore surface and a particle size of 1.0–1.4mm. The BET specific surface area of ​​the granular activated carbon is 1682m². 2 / g, with a pore volume of 0.71mL / g, and the ethane adsorption performance is shown in Table 1.

[0153] Elemental analysis using an Elementa Unicube instrument revealed that the nitrogen content in the amino-modified activated carbon material prepared in this embodiment was 1.66% by mass.

[0154] Example 9

[0155] Step 1: Carbonization Process. Using coconut shells as a precursor, the coconut shells were placed in a magnetic boat within a flowing argon atmosphere and then placed in a tube furnace for carbonization. The carbonization conditions included: an argon flow rate of 60 mL / min, a heating rate of 5 °C / min, a temperature of 500 °C, and a time of 60 min. The carbonized coconut shells were then pulverized, and the particles were sieved using 14- and 18-mesh sieves to obtain carbon precursor particles with a size of 1.0–1.4 mm and a BET specific surface area of ​​220 m². 2 / g, pore volume is 0.11mL / g.

[0156] Step 2: Activation Process. Weigh 5g of granular carbon precursor and 20g of powdered KOH to prepare a 40mol / L potassium hydroxide solution. Mix the granular carbon precursor and potassium hydroxide solution, then ultrasonically disperse for 15min. Dry at 120℃, and place the dried product in a magnetic boat in a tube furnace for high-temperature activation. The activation conditions are: argon flow rate of 60mL / min, heating rate of 5℃ / min, temperature of 800℃, and time of 120min. After activation, allow to cool to room temperature, remove the activated product from the tube furnace and place it in a beaker. Add 1mol / L hydrochloric acid solution dropwise until the solution is neutral. Filter to obtain solid particles, wash three times with deionized water, and dry in an 80℃ oven for 6h to obtain granular activated carbon precursor with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1943m². 2 / g, pore volume is 0.91mL / g.

[0157] Step 3: Surface oxidation modification of the granular activated carbon precursor. This is performed as follows: ① Weigh 3g of the granular activated carbon precursor into a beaker, then add 15mL of 30% hydrogen peroxide. React at 200r / min and room temperature (25℃) for 4 hours to obtain a granular activated carbon suspension; ② Filter the suspension to remove the liquid phase, obtaining the solid phase; ③ Mix the solid phase with deionized water, wash under ultrasonic conditions for 20 minutes, filter to obtain the solid product, repeat the washing process three times, and air-dry in a ventilated area for 15 hours; ④ Place the solid product in a vacuum oven and dry at 100℃ for 6 hours under an absolute pressure of 10kPa to obtain oxidized modified granular activated carbon with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1842m². 2 / g, pore volume is 0.82mL / g.

[0158] Step 4: Amine modification of the pore surface. This is performed as follows: ① Add 3g of oxidized modified granular activated carbon to a beaker, add 10mL of ethanol, then add 0.3g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane to the beaker, and ultrasonically disperse for 20min to obtain a granular activated carbon suspension; ② Place the suspension in a 70℃ water bath and react for 3h with a stirring speed of 200r / min; ③ After the reaction, filter to remove the liquid phase, obtaining granular activated carbon, rinse with ethanol, and air-dry in a ventilated area for 16h; ④ Place the activated carbon in a vacuum oven and dry at 80℃ under an absolute pressure of 10kPa for 10h to obtain granular activated carbon with an amino-modified pore surface and a particle size of 1.0–1.4mm. The BET specific surface area of ​​the granular activated carbon is 1720m². 2 / g, with a pore volume of 0.73mL / g, and ethane adsorption performance is shown in Table 1.

[0159] Elemental analysis using an Elementa Unicube instrument revealed that the nitrogen content in the amino-modified activated carbon material prepared in this embodiment was 1.26% by mass.

[0160] Example 10

[0161] Step 1: Carbonization Process. Using coconut shells as a precursor, the coconut shells were placed in a magnetic boat within a flowing argon atmosphere and then placed in a tube furnace for carbonization. The carbonization conditions included: an argon flow rate of 60 mL / min, a heating rate of 5 °C / min, a temperature of 500 °C, and a time of 60 min. The carbonized coconut shells were then pulverized, and the particles were sieved using 14- and 18-mesh sieves to obtain carbon precursor particles with a size of 1.0–1.4 mm and a BET specific surface area of ​​220 m². 2 / g, pore volume is 0.11mL / g.

[0162] Step 2: Activation Process. Weigh 5g of granular carbon precursor and 20g of powdered KOH to prepare a 40mol / L potassium hydroxide solution. Mix the granular carbon precursor and potassium hydroxide solution, then ultrasonically disperse for 15min. Dry at 120℃, and place the dried product in a magnetic boat in a tube furnace for high-temperature activation. The activation conditions are: argon flow rate of 60mL / min, heating rate of 5℃ / min, temperature of 800℃, and time of 120min. After activation, allow to cool to room temperature, remove the activated product from the tube furnace and place it in a beaker. Add 1mol / L hydrochloric acid solution dropwise until the solution is neutral. Filter to obtain solid particles, wash three times with deionized water, and dry in an 80℃ oven for 6h to obtain granular activated carbon precursor with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1943m². 2 / g, pore volume is 0.91mL / g.

[0163] Step 3: Surface oxidation modification of the granular activated carbon precursor. This is performed as follows: ① Weigh 3g of the granular activated carbon precursor into a beaker, then add 15mL of 10% hydrogen peroxide. React at 200r / min and room temperature (25℃) for 4 hours to obtain a granular activated carbon suspension; ② Filter the suspension to remove the liquid phase, obtaining the solid phase; ③ Mix the solid phase with deionized water, wash under ultrasonic conditions for 20 minutes, filter to obtain the solid product, repeat the washing process three times, and air-dry in a ventilated area for 15 hours; ④ Place the solid product in a vacuum oven and dry at 100℃ for 6 hours under an absolute pressure of 10kPa to obtain oxidation-modified granular activated carbon with a particle size of 1.0–1.4mm and a BET specific surface area of ​​2131m². 2 / g, pore volume is 0.98mL / g.

[0164] Step 4: Amine modification of the pore surface. This is performed as follows: ① Add 3g of oxidized modified granular activated carbon to a beaker, add 10mL of ethanol, then add 0.6g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane. Disperse ultrasonically for 20min to obtain a granular activated carbon suspension; ② Place the suspension in a 70℃ water bath and react for 3h with a stirring speed of 200r / min; ③ After the reaction, filter to remove the liquid phase, obtaining granular activated carbon. Rinse with ethanol and air-dry in a ventilated area for 16h; ④ Place the activated carbon in a vacuum oven and dry at 80℃ under an absolute pressure of 10kPa for 10h to obtain granular activated carbon with an amino-modified pore surface and a particle size of 1.0–1.4mm. The BET specific surface area of ​​the granular activated carbon is 1780m². 2 / g, with a pore volume of 0.81mL / g, and ethane adsorption performance is shown in Table 1.

[0165] Analysis using an Elementa Unicube elemental analyzer revealed that the nitrogen content in the amino-modified activated carbon material prepared in this embodiment was 1.37% by mass.

[0166] Example 11

[0167] Step 1: Carbonization Process. Using coconut shells as a precursor, the coconut shells were placed in a magnetic boat within a flowing argon atmosphere and then placed in a tube furnace for carbonization. The carbonization conditions included: argon flow rate of 60 mL / min, heating rate of 5℃ / min, temperature of 500℃, and time of 60 min. The carbonized coconut shells were then crushed, and the particles were sieved using 14-mesh and 18-mesh sieves to obtain carbon precursor particles with a size of 1.0–1.4 mm and a BET specific surface area of ​​220 m². 2 / g, pore volume is 0.11mL / g.

[0168] Step 2: Activation Process. Weigh 5g of granular carbon precursor and 20g of powdered KOH to prepare a 40mol / L potassium hydroxide solution. Mix the granular carbon precursor and potassium hydroxide solution, then ultrasonically disperse for 15min. Dry at 120℃ for 3h. Place the dried product in a magnetic boat and in a tube furnace for high-temperature activation. The activation conditions are: argon flow rate 60mL / min, heating rate 5℃ / min, temperature 800℃, and time 120min. After activation, allow to cool to room temperature. Remove the activated product from the tube furnace and place it in a beaker. Add 1mol / L hydrochloric acid solution dropwise until the solution is neutral. Filter to obtain solid particles, wash three times with deionized water, and dry in an 80℃ oven for 6h to obtain granular activated carbon precursor with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1943m². 2 / g, pore volume is 0.91mL / g.

[0169] Step 3: Surface oxidation modification of the granular activated carbon precursor. This is performed as follows: ① Weigh 3g of the granular activated carbon precursor into a beaker, then add 15mL of 20% hydrogen peroxide. React at 200r / min and room temperature (25℃) for 4 hours to obtain a granular activated carbon suspension; ② Filter the suspension to remove the liquid phase, obtaining the solid phase; ③ Mix the solid phase with deionized water, wash under ultrasonic conditions for 20 minutes, filter to obtain the solid product, repeat the washing process three times, and air-dry in a ventilated area for 15 hours; ④ Place the solid product in a vacuum oven and dry at 100℃ for 6 hours under an absolute pressure of 10kPa to obtain oxidized modified granular activated carbon with a particle size of 1.0–1.4mm and a BET specific surface area of ​​2012m². 2 / g, pore volume is 0.96mL / g.

[0170] Step 4: Amine modification of the pore surface. This is performed as follows: ① Add 3g of oxidized modified granular activated carbon to a beaker, add 10mL of ethanol, then add 0.6g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane to the beaker, and ultrasonically disperse for 20min to obtain a granular activated carbon suspension; ② Place the suspension in a 70℃ water bath and react for 3h with a stirring speed of 200r / min; ③ After the reaction, filter to remove the liquid phase, obtaining granular activated carbon, rinse with ethanol, and air-dry in a ventilated area for 16h; ④ Place the activated carbon in a vacuum oven and dry at 80℃ under an absolute pressure of 10kPa for 10h to obtain granular activated carbon with an amino-modified pore surface and a particle size of 1.0–1.4mm. The BET specific surface area of ​​the granular activated carbon is 1860m². 2 / g, with a pore volume of 0.76mL / g, and ethane adsorption performance is shown in Table 1.

[0171] Elemental analysis using an Elementa Unicube instrument revealed that the nitrogen content in the amino-modified activated carbon material prepared in this embodiment was 1.21% by mass.

[0172] Comparative Example 1

[0173] The specific operations include:

[0174] Step 1: Carbonization Process. Using coconut shells as a precursor, the coconut shells were placed in a magnetic boat within a flowing argon atmosphere and then placed in a tube furnace for carbonization. The carbonization conditions included: argon flow rate of 60 mL / min, heating rate of 5℃ / min, temperature of 500℃, and time of 60 min. The carbonized coconut shells were then crushed, and the particles were sieved using 14-mesh and 18-mesh sieves to obtain carbon precursor particles with a size of 1.0–1.4 mm and a BET specific surface area of ​​220 m². 2 / g, pore volume is 0.11mL / g.

[0175] Step 2: Activation Process. Weigh 5g of granular carbon precursor and 20g of powdered KOH to prepare a 40mol / L potassium hydroxide solution. Mix the granular carbon precursor and potassium hydroxide solution, then ultrasonically disperse for 15min. Dry at 120℃, and place the dried product in a magnetic boat in a tube furnace for high-temperature activation. The activation conditions are: argon flow rate of 60mL / min, heating rate of 5℃ / min, temperature of 800℃, and time of 120min. After activation, allow to cool to room temperature, remove the activated product from the tube furnace and place it in a beaker. Add 1mol / L hydrochloric acid solution dropwise until the solution is neutral. Filter to obtain solid particles, wash three times with deionized water, and dry in an 80℃ oven for 6h to obtain granular activated carbon precursor with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1943m².2 / g, pore volume is 0.91mL / g.

[0176] Comparative Example 2

[0177] The specific operations include:

[0178] Step 1: Carbonization Process. Using coconut shells as a precursor, the coconut shells were placed in a magnetic boat within a flowing argon atmosphere and then placed in a tube furnace for carbonization. The carbonization conditions included: argon flow rate of 60 mL / min, heating rate of 5℃ / min, temperature of 500℃, and time of 60 min. The carbonized coconut shells were then crushed, and the particles were sieved using 14-mesh and 18-mesh sieves to obtain carbon precursor particles with a size of 1.0–1.4 mm and a BET specific surface area of ​​220 m². 2 / g, pore volume is 0.11mL / g.

[0179] Step 2: Activation Process. Weigh 5g of granular carbon precursor and 20g of powdered KOH to prepare a 40mol / L potassium hydroxide solution. Mix the granular carbon precursor and potassium hydroxide solution, then ultrasonically disperse for 15min. Dry at 120℃, and place the dried product in a magnetic boat in a tube furnace for high-temperature activation. The activation conditions are: argon flow rate of 60mL / min, heating rate of 5℃ / min, temperature of 900℃, and time of 60min. After activation, allow to cool to room temperature, remove the activated product from the tube furnace and place it in a beaker. Add 1mol / L hydrochloric acid solution dropwise until the hydrochloric acid solution is neutral. Soak for 6h, filter to obtain solid particles, wash three times with deionized water, and dry in an 80℃ oven for 6h to obtain granular activated carbon precursor with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1880m². 2 / g, pore volume is 0.81mL / g.

[0180] Step 3: Surface oxidation modification of the granular activated carbon precursor. This is performed as follows: ① Weigh 3g of the granular activated carbon precursor into a beaker, then add 15mL of 20% hydrogen peroxide. React at 200r / min and room temperature (25℃) for 4 hours to obtain a granular activated carbon suspension; ② Filter the suspension to remove the liquid phase, obtaining the solid phase; ③ Mix the solid phase with deionized water, wash under ultrasonic conditions for 20 minutes, filter to obtain the solid phase, repeat the washing process three times, and air-dry in a ventilated area for 15 hours; ④ Place the solid phase in a vacuum oven and dry at 100℃ for 6 hours under an absolute pressure of 10kPa to obtain oxidized modified granular activated carbon with a particle size of 1.0–1.4mm and a BET specific surface area of ​​1936m². 2 / g, pore volume is 0.87mL / g.

[0181] Comparative Example 3

[0182] The specific operations include:

[0183] (1) Carbonization process. Using coconut shells as a precursor, the coconut shells were placed in a magnetic boat within a flowing argon atmosphere and then placed in a tube furnace for carbonization. The carbonization conditions included: argon flow rate of 60 mL / min, heating rate of 5 °C / min, temperature of 500 °C, and time of 60 min. The carbonized coconut shells were then crushed, and the particles were screened using 14-mesh and 18-mesh sieves to obtain carbon precursor particles with a size of 1.0–1.4 mm and a BET specific surface area of ​​220 m². 2 / g, pore volume is 0.11mL / g.

[0184] (2) Activation process. Weigh 5g of granular carbon precursor and 20g of powdered KOH to prepare a 40mol / L potassium hydroxide solution. Mix the granular carbon precursor and potassium hydroxide solution and disperse ultrasonically for 15min. Then dry at 120℃ for 3h. Place the dried product in a magnetic boat and place it in a tube furnace for high-temperature activation. The activation conditions include: argon flow rate of 60mL / min, heating rate of 5℃ / min, temperature of 900℃, and time of 60min. After activation, allow it to cool to room temperature, remove the activated product from the tube furnace and place it in a beaker. Add 1mol / L hydrochloric acid solution dropwise until the solution is neutral. Filter to obtain solid particles, wash three times with deionized water, and dry in an 80℃ oven for 6h to obtain granular activated carbon precursor with a particle size of 1.0-1.4mm and a BET specific surface area of ​​1880m². 2 / g, pore volume is 0.81mL / g.

[0185] (3) Amino-modified pore surface. The process was carried out as follows: ① 3g of oxidized granular activated carbon precursor was added to a beaker, followed by 10mL of ethanol. Then, 0.6g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane was added to the beaker, and the mixture was ultrasonically dispersed for 20min to obtain a granular activated carbon suspension. ② The suspension was placed in a 70℃ water bath and reacted for 3h with a stirring speed of 200r / min. ③ After the reaction, the mixture was filtered to remove the liquid phase, yielding granular activated carbon. The carbon was rinsed with ethanol and air-dried in a ventilated area for 16h. ④ The activated carbon was placed in a vacuum oven and dried at 80℃ under an absolute pressure of 10kPa for 10h to obtain granular activated carbon with an amino-modified pore surface and a particle size of 1.0–1.4mm. The BET specific surface area of ​​the granular activated carbon was 1730m². 2 / g, pore volume is 0.70mL / g.

[0186] Elemental analysis using an Elementa Unicube instrument revealed that the nitrogen content in the amino-modified activated carbon material prepared in this embodiment was 0.51% by mass.

[0187] Test Example 1: Ethane Adsorption Capacity Test

[0188] The ethane adsorption isotherm (25℃) of activated carbon was analyzed using a high-performance pore structure analyzer (BSD-660T) from Best Instruments Technology (Beijing) Co., Ltd. The built-in analytical methods were used to calculate and analyze the adsorption-desorption isotherm curve of activated carbon for ethane, and the adsorption capacity was calculated. The results are shown in Table 1.

[0189] The specific method includes: weighing approximately 200 mg of samples prepared in the examples and comparative examples; degassing the samples under vacuum at 300°C for 3 hours before testing; and testing the ethane adsorption-desorption isotherms of the materials at 0–100 kPa at 25°C. The ethane adsorption amounts of each sample at 25°C and 100 kPa are shown in Table 1. The nitrogen adsorption isotherms and ethane adsorption isotherms of Examples 1, 3, 6, and Comparative Example 1 are shown below. Figure 1 and Figure 2 As shown.

[0190] Test Example 2: Working Adsorption Capacity Test

[0191] The breakthrough adsorption curves of ethane gas for each sample prepared in the examples and comparative examples were determined using a multi-component adsorption breakthrough curve analyzer (BSD-MAB) from Best Instruments Technology (Beijing) Co., Ltd., and the working adsorption capacity of each sample for ethane was calculated. The results are shown in Table 1.

[0192] The specific procedure for determining the breakthrough curve of ethane gas is as follows: First, weigh approximately 3g of sample and load it into the breakthrough column. Purge the column with helium gas at a flow rate of 300mL / min for 2 hours to remove impurities from the sample surface. Place the breakthrough column in a constant temperature water bath at 298K. After the test environment stabilizes, begin the breakthrough experiment and test the ethane adsorption breakthrough curve (volume concentration 10%, flow rate 50mL / min). Calculate the working adsorption capacity of activated carbon for ethane. The results are shown in Table 1.

[0193] The adsorption capacity of each component is calculated using the following formula:

[0194] (No approximation)

[0195] Note: This calculation formula takes into account the concentration changes caused by real-time changes in the outlet flow rate due to adsorption, which improves the accuracy of calculating the adsorption amount by concentration integral and has no approximation.

[0196] Q n吸附Adsorption capacity of the adsorbent for adsorbate n (unit: mL)

[0197] Q n入总 Total flow rate of adsorbate n into the breakthrough column over time ΔT (unit: mL)

[0198] Q n出总 : Total flow rate of adsorbate n through the column during time ΔT (unit: mL)

[0199] q 总入 Total gas velocity at the inlet of the penetration column (unit: mL / min)

[0200] q 载气 Carrier gas flow rate (unit: mL / min)

[0201] C n0 : Percentage concentration (%) of adsorbate n at the inlet of the permeation column

[0202] C nt : Percentage concentration (%) of adsorbate n at the outlet of the permeation column at a certain moment.

[0203] ΔT: Total time from the start to the end of adsorption (unit: s) for the adsorption amount of each component.

[0204] Table 1

[0205]

[0206] Note: a The ethane adsorption capacity at 25℃ and 100kPa was obtained from the activated carbon ethane adsorption isotherm.

[0207] b The ethane adsorption capacity (outlet concentration / inlet concentration 95%) was obtained from the ethane breakthrough curve of activated carbon.

[0208] As can be seen from Table 1, the amino-modified activated carbon material prepared by the method of the present invention has a large specific surface area and pore volume; compared with the comparative example, the ethane adsorption capacity of the amino-modified activated carbon material prepared by the method of the present invention is significantly improved.

[0209] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An amino-modified activated carbon material, characterized in that, The amino-modified activated carbon material includes activated carbon and amino groups modified on the surface of the activated carbon; The specific surface area of ​​the amino-modified activated carbon material is 1500–2100 m². 2 / g, with a pore volume of 0.6~1.1mL / g.

2. The amino-modified activated carbon material according to claim 1, characterized in that, The amino-modified activated carbon material is in granular form; Preferably, the particle size of the amino-modified activated carbon material is 1-3 mm.

3. The amino-modified activated carbon material according to claim 1 or 2, characterized in that, Based on the total weight of the amino-modified activated carbon material, the nitrogen content is 0.3-3% by weight.

4. A method for preparing amino-modified activated carbon materials, characterized in that, The method includes the following steps: (1) Carbonize the carbon source to obtain a carbon precursor; (2) The carbon precursor is mixed with an alkaline source for activation, and then treated with acid to obtain the activated carbon precursor; (3) The surface of the activated carbon precursor is modified by using an oxidant to modify the surface of the activated carbon precursor with carboxyl and hydroxyl groups; (4) The product obtained in step (3) is modified with an amino reagent.

5. The method according to claim 4, characterized in that, Step (1) includes: carbonizing the carbon source in an inert atmosphere, then crushing and sieving to obtain a particulate carbon precursor; Preferably, the carbon precursor has a particle size of 1–1.4 mm and a BET specific surface area of ​​100–400 m². 2 / g, pore volume is 0.05~0.2mL / g; Preferably, the carbon source is selected from one or more of coconut shells, apricot shells, walnut shells, and bamboo.

6. The method according to claim 4 or 5, characterized in that, The carbonization conditions include: an inert atmosphere flow rate of 50–70 mL / min, a heating rate of 2–10 °C / min, a temperature of 400–600 °C, and a time of 30–180 min.

7. The method according to any one of claims 4-6, characterized in that, In step (2), the weight ratio of the carbon precursor to the alkaline source is 1:1 to 5; Preferably, the activation conditions include: an inert atmosphere flow rate of 40–80 mL / min, a heating rate of 1–10 °C / min, an activation temperature of 500–900 °C, and an activation time of 30–120 min; Preferably, the alkali source is one or more of KOH, K2CO3 and NaNH2.

8. The method according to any one of claims 4-7, characterized in that, In step (2), the carbon precursor and the alkali source are mixed by solution impregnation or solid mixing.

9. The method according to any one of claims 4-8, characterized in that, In step (2), the acid treatment process includes: adding an acidic solution dropwise to the activated product until the pH of the solution is 6.5 to 7.5, then filtering, washing, and drying to obtain granular activated carbon precursor; Preferably, the concentration of the acidic solution is 0.5–1.5 mol / L; Preferably, the acid in the acidic solution is selected from one or more of hydrochloric acid, sulfuric acid, and nitric acid; Preferably, the activated carbon precursor has a particle size of 1–1.4 mm and a BET specific surface area of ​​1400–2500 m². 2 / g, with a pore volume of 0.5~1.4mL / g.

10. The method according to any one of claims 4-8, characterized in that, In step (3), the oxidant is selected from one or more of hydrogen peroxide, concentrated sulfuric acid, concentrated nitric acid and ozone.

11. The method according to any one of claims 4-10, characterized in that, When the oxidant is hydrogen peroxide, the specific method for surface modification of activated carbon precursor using oxidant is as follows: react the activated carbon precursor with hydrogen peroxide, and then sequentially perform solid-liquid separation, ultrasonic washing and drying on the reaction product. Preferably, the solid-liquid ratio of activated carbon precursor to hydrogen peroxide is 1g:(1-10)mL, and the concentration of hydrogen peroxide is 1-30% by weight. Preferably, the reaction conditions include a temperature of 10–30°C and a time of 4–7 hours.

12. The method according to any one of claims 4-11, characterized in that, In step (4), the amino reagent is selected from one or more of 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-ureapropyltrimethoxysilane, hexamethylenediaminemethyltrimethoxysilane, anilinemethyltrimethoxysilane, 3-aminopropyltriethoxysilane, (2-aminoisopropyl)triethoxysilane, 3-(4-ureaamino)propyltriethoxysilane, and N-aminoethyl-3-aminopropyltriethoxysilane; Preferably, the weight ratio of the product obtained in step (3) to the amount of amino reagent is (2-40):

1.

13. The method according to any one of claims 4-12, characterized in that, Step (4) includes: ultrasonically dispersing the product obtained in step (3), the organic solvent and the amino reagent, then reacting the obtained product in a water bath, and then sequentially performing solid-liquid separation, washing and drying of the reaction product; Preferably, the organic solvent is selected from one or more of ethanol, ethyl acetate, methanol, and chloroform; Preferably, the solid-liquid ratio of the product obtained in step (3) to the organic solvent is 1 g: (1-3) mL; Preferably, the ultrasonic dispersion time is 10–60 min; Preferably, the reaction conditions include a temperature of 50–80°C and a time of 1–5 hours.

14. The amino-modified activated carbon material prepared by the method according to any one of claims 4-13.

15. The application of the amino-modified activated carbon material according to any one of claims 1, 2, 3 or 14 in the adsorption of light hydrocarbons; Preferably, the light hydrocarbon is methane and / or ethane.

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