Adsorbing material, preparation method thereof and method for removing VOCs (Volatile Organic Compounds)

Abstract

The invention relates to a method for preparing an adsorption material, and the method comprises the following steps: active carbon, transition metal chloride, an activator and olefin are contacted and react to obtain the adsorption material, and the activator is triethylamine hydrochloride chloroaluminate. According to the present invention, the activator and the transition metal chloride are adopted as the catalyst, the olefin is subjected to the reaction under the action of the catalyst, such that the olefin is loaded on the surface of the active carbon so as to effectively improve the hydrophobic property of the adsorption material, and the adsorption capacity and the moisture resistance of the material on the high-humidity VOCs can be effectively improved; after the adsorption material provided by the invention is in contact with a high-humidity material flow containing VOCs, the adsorption quantity of the VOCs can be effectively improved. And the preparation process is simple, low in cost and easy for large-scale production.

Description

Technical Field

[0001] This disclosure belongs to the field of adsorption materials, specifically relating to an adsorption material, its preparation method, and a method for removing VOCs. Background Technology

[0002] Volatile organic compounds (VOCs) mainly include aliphatic hydrocarbons, halogenated hydrocarbons, aromatic hydrocarbons, alcohols, aldehydes, esters, ethers, ketones, carboxylic acids, amines, and sulfur-containing organic compounds. VOCs readily react with nitrogen oxides (NOx) in the atmosphere through photochemical reactions, forming photochemical smog and causing even more serious pollution hazards. In addition, VOCs directly harm human health. Inhalation of aromatic hydrocarbons can damage the central nervous system, causing neurological disorders, endangering the blood and hematopoietic organs, and in severe cases, leading to bleeding symptoms or sepsis. Therefore, controlling VOC emissions is of great significance.

[0003] To effectively remove VOCs from aquatic and high-humidity environments, CN108786719A discloses a material for VOCs adsorption and its preparation method. The adsorbent material consists of a molecular sieve adsorbent and a catalyst. The molecular sieve adsorbent is a ZSM-5 / USY mixed molecular sieve, and the catalyst is a mixture of Pt / BN and CeO2-ZrO2. The resulting adsorbent material has a large adsorption capacity and does not form carbon deposits during desorption, making it easy to regenerate. However, the adsorbent material prepared by the above method has poor moisture resistance, resulting in poor adsorption performance in aquatic and high-humidity environments, and cannot effectively remove VOCs. CN110302830A discloses a molecular sieve-based catalyst for VOCs purification in high-humidity environments, its preparation method, and its application. The molecular sieve is impregnated in an aqueous solution of a noble metal compound, dispersed, and then aged to obtain a mixed solution. Water is then removed from the mixed solution to obtain a solid. The solid is then calcined to obtain the molecular sieve-based catalyst for VOCs purification in high-humidity environments. This catalyst exhibits excellent adsorption capacity for VOCs and moisture resistance, but the addition of precious metals or expensive catalysts during its preparation process results in high costs, making it difficult to promote industrial production. Summary of the Invention

[0004] The purpose of this invention is to provide an adsorption material, its preparation method, and a method for removing VOCs. The adsorption material prepared by the method provided by this invention has excellent adsorption performance and moisture resistance, and can effectively remove low concentrations of VOCs in aquatic or high-humidity gas environments.

[0005] To achieve the above objectives, a first aspect of the present invention provides a method for preparing an adsorbent material, wherein the method includes: Activated carbon, transition metal chlorides, activators, and olefins are contacted together to obtain an adsorbent material through a reaction. The activator includes triethylamine chloroaluminate hydrochloride.

[0006] Optionally, the reaction is carried out in solution, and the solvent includes one or more of nitrobenzene, ethanol and chloroform; The method includes: impregnating the activated carbon in a solution containing the activator, then adding the transition metal chloride to obtain a precursor mixture, and reacting the precursor mixture with the olefin; the impregnation temperature is 15~25℃ and the time is 1~3h. In the solution containing the activator, the concentration of triethylamine chloroaluminate hydrochloride is 10~30 wt%.

[0007] Optionally, the transition metal includes a Group IB metal in the periodic table; preferably, the transition metal chloride includes CuCl2 and / or AgCl.

[0008] Optionally, the mass ratio of activated carbon to olefin is 1:(0.1~0.3); the mass ratio of activated carbon to transition metal chloride is 1:(0.01~0.03).

[0009] Optionally, the olefin includes an α-olefin having 7 to 16 carbon atoms.

[0010] Optionally, the reaction temperature is 15~25℃, the reaction time is 1~3h, and the reaction pressure is 0~0.4MPa.

[0011] Optionally, the method further includes: in step S2, after the reaction is completed, the solid product is dried to obtain the adsorbent material; the drying temperature is 80~110℃ and the time is 12~24h.

[0012] A second aspect of the present invention provides an adsorbent material prepared using the method described in the first aspect of the present invention.

[0013] Optionally, the specific surface area of ​​the adsorbent material is 2000~2800 m². 2 / g, pore volume is 1.4~1.5ml / g, and average pore size is 1.5~2.7nm.

[0014] A third aspect of the present invention provides a method for removing VOCs, wherein the method includes: contacting VOCs with an adsorbent material containing the adsorbent material described in the second aspect of the present invention at a temperature of 290~320°C.

[0015] Through the above technical solution, this invention prepares an adsorbent material by contacting activated carbon, transition metal chlorides, an activator, and olefins via a reaction. In this invention, the activator and transition metal chlorides act as catalysts, and the olefins react under the catalytic action, allowing the olefins to be loaded onto the surface of the activated carbon. This effectively enhances the hydrophobic properties of the adsorbent material. This invention effectively improves the material's adsorption capacity and moisture resistance for high-humidity VOCs. When the adsorbent material provided by this invention is contacted with high-humidity VOC-containing gases, it can effectively remove VOCs from the high-humidity gases. Furthermore, the preparation process of this invention is simple, low-cost, and easy to scale up for production.

[0016] Other features and advantages of the present invention will be described in detail in the following detailed description section. Detailed Implementation

[0017] The following provides a detailed description of specific embodiments of this disclosure. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit this disclosure.

[0018] The first aspect of this disclosure provides a method for preparing an adsorbent material, wherein the method includes: Activated carbon, transition metal chloride, activator and olefin are contacted and reacted to obtain adsorbent material. The activator includes triethylamine chloroaluminate hydrochloride, preferably triethylamine chloroaluminate hydrochloride.

[0019] In this invention, activators and transition metal chlorides are supported as catalysts on activated carbon materials, allowing olefins to react under the action of the catalyst. The vinyl groups obtained after the reaction of the olefins give the adsorbent material excellent hydrophobic properties. This invention can effectively improve the material's adsorption capacity and moisture resistance for high-humidity VOCs. When the adsorbent material provided by this invention is contacted with high-humidity VOC-containing gases, it can effectively remove VOCs from the high-humidity gases. Furthermore, the preparation process of this invention is simple, low-cost, and easy to scale up for production.

[0020] In one specific embodiment, the reaction is carried out in solution, and the solvent includes one or more of nitrobenzene, ethanol, and chloroform, preferably nitrobenzene; the method includes: impregnating the activated carbon in a solution containing the activator, then adding the transition metal chloride to obtain a precursor mixture, and contacting the precursor mixture with the olefin for reaction; the impregnation temperature is 10~40℃, preferably 15~25℃, more preferably 20~25℃, and the time is 1~3h, preferably 1~2h; the concentration of triethylamine aluminate hydrochloride in the solution containing the activator is 10~30wt%, preferably 15~25wt%. In the above embodiment, controlling the concentration of triethylamine aluminate hydrochloride in the diluent within the preferred range of this application can further improve the catalytic efficiency of the subsequent reaction, giving the modified activated carbon material better hydrophobic properties, and further improving the material's adsorption capacity and moisture resistance for high-humidity VOCs.

[0021] In one specific embodiment, the transition metal is selected from metals in Group IB of the periodic table; in a preferred embodiment, the transition metal chloride includes CuCl2 and / or AgCl, preferably CuCl2.

[0022] In one specific embodiment, the mass ratio of activated carbon to transition metal chloride is 1:(0.01~0.03), preferably 1:(0.02~0.03). In the above embodiment, controlling the mass ratio of activated carbon to transition metal chloride within the preferred range of this application can further improve the catalytic efficiency of subsequent reactions, thereby further enhancing the material's adsorption capacity and moisture resistance to high-humidity VOCs.

[0023] In one specific embodiment, the mass ratio of activated carbon to olefin is 1:(0.1~0.3), preferably 1:(0.1~0.2). In the above embodiment, controlling the mass ratio of activated carbon to olefin within the preferred range of this application enables the modified activated carbon material to possess superior hydrophobic properties, further enhancing the material's adsorption capacity for high-humidity VOCs and its moisture resistance.

[0024] In one specific embodiment, the olefin includes an α-olefin having 7 to 16 carbon atoms, preferably an α-olefin having 7 to 14 carbon atoms.

[0025] In one specific embodiment, in step S2, the reaction temperature is 10~40℃, preferably 15~25℃, more preferably 20~25℃, the reaction time is 1~3h, preferably 1~2h, and the reaction pressure is 0~0.4MPa, preferably 0.1~0.3MPa.

[0026] In one specific embodiment, the method further includes: in step S2, after the reaction is completed, the solid product is dried to obtain the adsorbent material; the drying temperature is 80~110℃ and the time is 12~24h, preferably, the temperature is 90~100℃ and the time is 20~24h.

[0027] The second aspect of this disclosure provides an adsorbent material prepared using the method described in the first aspect of the present invention.

[0028] In one specific embodiment, the specific surface area of ​​the adsorbent material is 2000~2800 m². 2 / g, preferably 2100~2300m 2 / g, pore volume is 1.4~1.5ml / g, preferably 1.4~1.45ml / g, average pore size is 1.5~3nm, preferably 2~2.8nm.

[0029] The adsorbent material provided in this disclosure possesses excellent specific surface area, pore volume, pore size, and contact angle, further enhancing its hydrophobic properties. This effectively improves the material's adsorption capacity and moisture resistance for VOCs in high-humidity environments. When the adsorbent material provided by this invention is brought into contact with high-humidity VOCs-containing gases, the adsorption capacity for VOCs can be further increased. Furthermore, the preparation process of this invention is simple, low-cost, and easily scalable for mass production.

[0030] The third aspect of this disclosure provides a method for removing VOCs, wherein the method includes: contacting VOCs with an adsorbent material containing the adsorbent material described in the second aspect of the present invention at a temperature of 290~320°C; wherein the stream comprises an aqueous solution or a high-humidity gas, wherein the humidity of the high-humidity gas is above 80%.

[0031] The present invention will be further illustrated by the following examples, but the present invention is not limited thereto.

[0032] Temperature nitrogen adsorption-desorption (BET) tests were performed on a surface area and pore size analyzer (ASAP 2020, Micromeritics). Specific surface area and pore volume were calculated using the two-parameter BET equation, while the average pore size was calculated and statistically analyzed using the BJH method.

[0033] Example 1 S0. 100g of activated carbon (PCT-12 activated carbon, sourced from Shandong Pengda Ecological Technology Co., Ltd.) is immersed in a diluent to obtain a diluent containing activated carbon; wherein, the immersion temperature is 25℃ and the immersion time is 2h; the diluent contains triethylamine chloroaluminate hydrochloride, and the concentration of triethylamine chloroaluminate hydrochloride in the diluent is 30wt%.

[0034] S1. Mix the diluted solution containing activated carbon with the transition metal chloride at 25°C for 2 hours to obtain a modified activated carbon precursor; wherein the mass ratio of activated carbon to transition metal chloride is 1:0.03; and the transition metal chloride is CuCl2.

[0035] S2. The modified activated carbon precursor from step S1 is mixed with an olefin and reacted at 25°C for 3 hours under atmospheric pressure. Then, the mixture is dried to obtain the adsorbent material. The mass ratio of activated carbon to olefin is 1:0.3. The olefin is an α-olefin with 7 carbon atoms. The drying temperature is 100°C and the time is 24 hours.

[0036] The specific surface area of ​​the adsorbent material prepared in this embodiment is 2111.19 m². 2 / g, pore volume is 1.43ml / g, and average pore size is 2.7nm.

[0037] Example 2 The method of Example 1 is used, except that in step S2, the olefin is an α-olefin with 14 carbon atoms.

[0038] Example 3 The method of Example 1 was used, except that the concentration of triethylamine chloroaluminate hydrochloride in the diluent was 20 wt%.

[0039] Example 4 The method of Example 1 was used, except that the mass ratio of activated carbon to olefins was 1:0.2.

[0040] Example 5 The method of Example 1 is used, except that the olefin is an α-olefin with 20 carbon atoms.

[0041] Comparative Example 1 The activated carbon material was purchased directly (PCT-12 activated carbon, purchased from Shandong Pengda Ecological Technology Co., Ltd.).

[0042] Test case The toluene adsorption capacity of the adsorbents in Examples 1-5 and Comparative Example 1 was obtained using a dynamic adsorption device. Specific test conditions included: 100 mg of the adsorbents prepared in the examples and comparative examples of this application were loaded into the reaction device as adsorbents; then a mixture of water and toluene was injected, wherein the molar ratio of water to toluene was 3:7; the adsorption pressure was 100 kPa; the adsorption temperature was 25 °C; and the inlet concentration of toluene was 200 ppm. The amount of toluene was monitored online using a GC-FID (SP-3510, Beifen Ruili, China) analyzer. The test results of the toluene adsorption capacity of each sample are shown in Table 1.

[0043] The amount of toluene adsorbed is calculated using equation (1): Toluene adsorption capacity = (mass of toluene before adsorption - mass of toluene after adsorption) / mass of adsorbent material (Equation 1).

[0044] Table 1

[0045] As can be seen from the test results in Table 1, the method provided in this application, which allows olefins to react under the action of a catalyst and be loaded onto the surface of activated carbon, can effectively improve the hydrophobic properties of the adsorption material, and effectively enhance the material's adsorption capacity and moisture resistance for high-humidity VOCs. When the adsorption materials provided in Examples 1-5 of this disclosure are contacted with toluene in an aqueous environment, the toluene adsorption capacity can be effectively increased. Furthermore, the preparation process of this invention is simple, low-cost, and easy to scale up for production.

[0046] Comparing Example 1 and Example 5, it can be seen that controlling the number of carbon atoms in the α-olefin within the preferred range of this application can further increase the pore volume of the prepared adsorbent material, and the toluene adsorption capacity can be effectively increased after contacting it with toluene.

[0047] Comparing Comparative Example 1 with Example 1, it can be seen that since the activated carbon surface is not loaded with olefins, the hydrophobicity of the material is poor, resulting in its adsorption capacity for high humidity VOCs and its moisture resistance being worse than that of Examples 1-5 of this application. Therefore, after contacting toluene in a high humidity environment, the amount of toluene adsorbed is significantly reduced.

[0048] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0049] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0050] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preparing an adsorbent material, wherein, The method includes: Activated carbon, transition metal chlorides, activators, and olefins are contacted together to obtain an adsorbent material through a reaction. The activator includes triethylamine chloroaluminate hydrochloride.

2. The method according to claim 1, wherein, The reaction is carried out in solution, and the solvent includes one or more of nitrobenzene, ethanol and chloroform; The method includes: impregnating the activated carbon in a solution containing the activator, then adding the transition metal chloride to obtain a precursor mixture, and reacting the precursor mixture with the olefin; the impregnation temperature is 15~25℃ and the time is 1~3h. In the solution containing the activator, the concentration of triethylamine chloroaluminate hydrochloride is 10~30 wt%.

3. The method according to claim 1, wherein, The transition metal includes a Group IB metal in the periodic table; preferably, the transition metal chloride includes CuCl2 and / or AgCl.

4. The method according to claim 1, wherein, The mass ratio of the activated carbon to the olefin is 1:(0.1~0.3). The mass ratio of the activated carbon to the transition metal chloride is 1:(0.01~0.03).

5. The method according to claim 1, wherein, The olefins include α-olefins having 7 to 16 carbon atoms.

6. The method according to claim 1, wherein, The reaction temperature is 15~25℃, the reaction time is 1~3h, and the reaction pressure is 0~0.4MPa.

7. The method according to claim 1, wherein, The method further includes: in step S2, after the reaction is completed, the solid product is dried to obtain the adsorbent material; the drying temperature is 80~110℃ and the time is 12~24h.

8. An adsorbent material prepared by the method according to any one of claims 1 to 7.

9. The adsorbent material according to claim 8, wherein, The specific surface area of ​​the adsorbent material is 2000~2800 m². 2 / g, pore volume is 1.4~1.5ml / g, and average pore size is 1.5~2.7nm.

10. A method for removing VOCs, wherein, The method includes contacting a VOC-containing stream with an adsorbent material as described in claim 8 or 9 at a temperature of 290 to 320°C.

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