A preparation process for a chemical waste gas adsorbent

Abstract

This invention relates to the field of waste gas purification technology, specifically a preparation process for a chemical waste gas adsorbent. This invention prepares a chemical waste gas adsorbent with high adsorption capacity, high selectivity, good stability, and renewability by chemically grafting adsorbents onto the surface of inorganic porous materials to adsorb macromolecular substances in industrial waste gas, combined with other functional treatment steps. This achieves efficient adsorption and removal of various pollutants in chemical waste gas, effectively filling the technical deficiencies of existing adsorbents, improving the efficiency and quality of chemical waste gas treatment, and reducing environmental pollution.

Description

Technical Field

[0001] This invention relates to the field of waste gas purification technology, specifically a preparation process for a chemical waste gas adsorbent. Background Technology

[0002] The chemical industry generates large amounts of complex waste gases during production, including volatile organic compounds (VOCs), acidic gases (such as sulfur dioxide and nitrogen oxides), alkaline gases (such as ammonia), and gaseous pollutants containing heavy metals. If these waste gases are released directly into the atmosphere without effective treatment, they will cause serious environmental pollution, leading to environmental problems such as smog and acid rain, and will also pose a great threat to human health, potentially causing respiratory diseases, cardiovascular diseases, and even cancer.

[0003] Currently, adsorption is one of the commonly used methods for treating chemical waste gas, and its core lies in the performance of the adsorbent. Traditional adsorbents such as activated carbon and silica gel, while possessing certain adsorption capabilities, have many limitations. Activated carbon exhibits poor selectivity for different pollutants, making it difficult to efficiently remove specific waste gas components; the adsorption performance of silica gel is significantly affected by ambient humidity, with adsorption efficiency decreasing markedly in high humidity environments. In recent years, researchers have attempted to improve the performance of adsorbent materials by modifying them. Chemical grafting technology, as an effective modification method, can introduce functional groups or macromolecules onto the material surface, endowing the material with new adsorption properties. However, existing chemical waste gas adsorbents prepared using chemical grafting technology still have shortcomings in adsorption efficiency, selectivity, stability, and the ability to synergistically treat multiple pollutants, failing to meet increasingly stringent environmental protection requirements. Summary of the Invention

[0004] The purpose of this invention is to provide a preparation process for a chemical waste gas adsorbent. By chemically grafting adsorbents onto the surface of an inorganic porous material, the adsorbent can adsorb macromolecular substances in industrial waste gas. Combined with other functional treatment steps, a chemical waste gas adsorbent with high adsorption capacity, high selectivity, good stability, and renewability is prepared. This achieves efficient adsorption and removal of various pollutants in chemical waste gas, effectively filling the technical defects of existing adsorbents, improving the efficiency and quality of chemical waste gas treatment, and reducing environmental pollution.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A preparation process for a chemical waste gas adsorbent includes the following steps:

[0007] Step 1: Under nitrogen protection, slowly add 0.85 to 0.9 times the volume of methyl acrylate and 1.5 to 2.5 times the volume of methanol to diethylenetriamine in an ice-water bath. After mixing and stirring evenly, react at room temperature for 4 to 6 hours. After the reaction is complete, recover the residual solvent in the product by vacuum distillation. Store the obtained reaction monomer for later use.

[0008] Step 2: Add the aminated activated carbon and the aminated composite substrate to 8-15 times their weight in the reaction monomers, mix well, and react at 65-75°C for 2-3 hours, then raise the temperature to 80-95°C for 3-5 hours. Filter the reaction products, wash them with methanol 4-5 times, and vacuum dry them to obtain the modified activated carbon and the modified composite substrate, respectively. The composite substrate is graphene oxide loaded with nano-titanium dioxide.

[0009] Step 3: After the modified activated carbon is activated twice, it is added to a mixing device along with 6-10% nano-cerium oxide and 15-20% modified composite substrate by mass, and after mixing, the chemical waste gas adsorbent is obtained.

[0010] Furthermore, the preparation method of the aminated composite substrate is as follows: 3-aminopropyltrimethoxysilane is uniformly dispersed in an ethanol aqueous solution with a volume concentration of 85-90% at a dosage ratio of 0.1-0.2 g / mL. After adjusting the pH to 3.6-4.2 with formic acid, 3-5 times the mass of the composite substrate is added, and the mixture is stirred and reacted at a temperature of 50-60°C for 5-8 hours. After the reaction is completed, the reaction product is sequentially filtered, washed with water, and dried.

[0011] Furthermore, the activated carbon is selected from either coconut shell activated carbon or apricot kernel shell activated carbon, and its particle size is 2-4 mm.

[0012] Furthermore, the composite substrate is prepared as follows: acetic acid, anhydrous ethanol, and tetrabutyl titanate are mixed and stirred at a volume ratio of 0.15–0.25:1:4–6 for 40–60 min; then, an aqueous dispersion of graphene oxide is added to the resulting gel, and the mixture is stirred at a rate of 300–500 r / min for 80–150 min; the resulting mixture is transferred to a microwave reactor and treated at a power of 500 W for 50–80 min; finally, the mixture is dried and sintered to obtain the composite substrate; wherein the concentration of graphene oxide in the aqueous dispersion of graphene oxide is 30–60 g / L, and the amount of graphene oxide used is 5–8% of the mass of the gel.

[0013] Furthermore, the drying temperature is 100–120°C, and the drying time is 100–150 min.

[0014] Furthermore, the sintering temperature is set to 400–480°C, and the sintering time is set to 2–3 hours.

[0015] Furthermore, the preparation method of the aminated activated carbon is as follows: the pretreated activated carbon is ultrasonically dispersed in thionyl chloride at a mass of 6 to 10 times its mass, and after reflux reaction for 2 to 3 hours, excess thionyl chloride is recovered by vacuum distillation. N,N-dimethylformamide at a mass of 4 to 6 times its mass is added to the remaining components after distillation, and triethylamine at a mass of 10 to 15 times its mass and triethylenetetramine at a mass of 1.5 to 2 times their mass are added dropwise under ice-water bath conditions. After stirring and reacting for 3 to 5 hours, the product components are filtered. The filter cake is washed alternately with ethanol and deionized water until the washing liquid is neutral, and then dried.

[0016] Furthermore, the method for preparing the pretreated activated carbon is as follows: the cleaned and dried activated carbon is immersed in a 5-10 wt% potassium permanganate solution, the pH is adjusted to 3.5-4 with dilute sulfuric acid, and the carbon is kept at 30-40°C for 10-15 hours; then, after solid-liquid separation, water washing and drying, the pretreated activated carbon is obtained.

[0017] Furthermore, the specific steps for the initial activation are as follows: by weight, mix 40-50 parts of aminated activated carbon, 1.5-2.5 parts of tetramethylolmethane, 0.5-0.8 parts of tannic acid, 0.1-0.3 parts of citric acid, 0.2-0.4 parts of carotene, 3-5 parts of ethyl acetate, and 50-75 parts of an ethanol aqueous solution with a volume concentration of 20-40%, and heat-treat at a temperature of 40-50°C for 2-4 hours; then evaporate and dehydrate.

[0018] Furthermore, the specific steps for secondary activation are as follows: the activated material obtained after the first activation is mixed with ammonium molybdate (4-6% by mass) and sodium tripolyphosphate (8-12% by mass) of aminated activated carbon, and then heat-treated at 120-140°C for 25-35 minutes under nitrogen protection.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. This invention prepares graphene oxide loaded with nano-titanium dioxide, i.e., a composite substrate, using tetrabutyl titanate and graphene oxide as raw materials. The surface of graphene oxide is rich in oxygen-containing functional groups such as hydroxyl, carboxyl, and epoxy groups, which can adsorb polar molecules and aromatic compounds through hydrogen bonding, electrostatic interactions, or π-π stacking. Nano-titanium dioxide possesses photocatalytic activity, generating electron-hole pairs under ultraviolet light excitation, producing hydroxyl radicals and superoxide radicals, which can oxidize and degrade pollutants in industrial waste gases. Furthermore, graphene oxide and nano-titanium dioxide are combined through π-π conjugation, electrostatic interactions, or chemical bonds (such as Ti-OC bonds) to form an integrated "adsorption-catalysis" system: graphene oxide enhances the dispersibility of nano-titanium dioxide, inhibiting its aggregation, while simultaneously acting as an electron acceptor to accelerate charge separation and enhance photocatalytic efficiency. Nano-titanium dioxide then photocatalytically degrades pollutants adsorbed by graphene oxide, avoiding adsorption site saturation and achieving highly efficient adsorption and purification of pollutants and polluting gases in industrial waste gases.

[0021] 2. This invention uses potassium permanganate to pretreat activated carbon, introducing numerous highly polar oxygen-containing functional groups (such as hydroxyl and carboxyl groups) onto the activated carbon surface. The pretreated activated carbon is then aminated, laying the foundation for subsequent grafting of hyperbranched polymers. The aminated composite substrate and aminated activated carbon are separately added to the reactants, where the reactants react with the relevant active groups on both surfaces, ultimately grafting hyperbranched polymers onto their surfaces and interiors. The presence of the hyperbranched polymer creates a dense three-dimensional envelope on the surface and interior of the modified activated carbon and modified composite substrate, significantly improving the physical adsorption performance of the adsorbent. Furthermore, due to the high amino density on the molecular chains of hyperbranched polymers, the prepared adsorbents can not only effectively adsorb acidic gases (such as SO2, CO2, and NOx), halogenated hydrocarbons, and polar VOCs (such as formaldehyde and acetone) in waste gases, but also form stable chelates with metal ions through coordination, thereby achieving the effect of adsorbing heavy metals (Hg, Cd, Pb, and other metal vapors or compounds).

[0022] 3. During the initial activation of modified activated carbon, the polyhydroxyl groups of tetramethylolmethane form a three-dimensional network structure with the amino groups on the surface of the modified activated carbon through hydrogen bonding or condensation reactions, increasing the adsorption sites. Tannic acid (containing phenolic hydroxyl groups) and carotene (containing conjugated double bonds) adhere to the surface of the modified activated carbon through π-π stacking and polar interactions, enhancing their affinity for polar VOCs (such as formaldehyde) and aromatic compounds (such as toluene). Ethyl acetate acts as a solvent to promote uniform dispersion, and after evaporation, it optimizes the pore structure and improves the physical adsorption capacity.

[0023] During the secondary activation process, ammonium molybdate decomposes at high temperature to generate MoO3, which is loaded onto the surface of modified activated carbon. This catalyzes the oxidation of SO2 and NOx to sulfates / nitrates, while simultaneously enhancing the oxidative adsorption of mercury. Sodium tripolyphosphate reacts with metallic impurities on the activated carbon surface to form a phosphate film, inhibiting amino decomposition at high temperatures and improving water resistance and mechanical strength. Furthermore, the semiconductor properties of MoO3 form a heterojunction with activated carbon, promoting electron transfer. This synergistic effect between MoO3 and the modified composite substrate enhances the efficiency of photocatalytic degradation of VOCs. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Example 1

[0025] A preparation process for a chemical waste gas adsorbent includes the following steps:

[0026] Step 1: Under nitrogen protection, slowly add 0.85 times the volume of methyl acrylate and 1.5 times the volume of methanol to diethylenetriamine in an ice-water bath. After mixing and stirring evenly, react at room temperature for 4 hours. After the reaction is complete, recover the residual solvent in the product by vacuum distillation. Store the obtained reaction monomer for later use.

[0027] Step 2: Add the aminated activated carbon and the aminated composite substrate to the reaction monomers, which are 8 times their weight, respectively. After mixing, react at 65°C for 3 hours, and then at 80°C for 5 hours. Filter the reaction products, wash them with methanol four times, and vacuum dry them to obtain the modified activated carbon and the modified composite substrate, respectively. The composite substrate is graphene oxide loaded with nano-titanium dioxide.

[0028] Step 3: After the modified activated carbon is activated twice, it is added to the mixing equipment along with 6% nano-cerium oxide and 15% modified composite substrate by mass, and after mixing, the chemical waste gas adsorbent is obtained.

[0029] The preparation method of the aminated composite substrate is as follows: 3-aminopropyltrimethoxysilane is uniformly dispersed in an 85% ethanol aqueous solution at a dosage ratio of 0.1 g / mL. After adjusting the pH to 3.6 with formic acid, the composite substrate with a mass of 3 times that of 3-aminopropyltrimethoxysilane is added, and the mixture is stirred and reacted at 50°C for 8 hours. After the reaction is completed, the reaction product is filtered, washed with water, and dried in sequence.

[0030] The activated carbon used is coconut shell activated carbon with a particle size of 2mm.

[0031] The composite substrate was prepared as follows: Acetic acid, anhydrous ethanol, and tetrabutyl titanate were mixed and stirred at a volume ratio of 0.15:1:4 for 40 min. Then, an aqueous dispersion of graphene oxide was added to the resulting gel and stirred at a rate of 300 r / min for 150 min. The resulting mixture was transferred to a microwave reactor and treated at a power of 500 W for 50 min. After drying and sintering, the composite substrate was obtained. The concentration of graphene oxide in the aqueous dispersion of graphene oxide was 30 g / L, and the amount of graphene oxide was 5% of the mass of the gel. The drying temperature was 100℃ and the drying time was 150 min. The sintering temperature was set to 400℃ and the sintering time was set to 3 h.

[0032] The preparation method of aminated activated carbon is as follows: pretreated activated carbon is ultrasonically dispersed in thionyl chloride at a mass of 6 times its mass. After reflux reaction for 2 hours, excess thionyl chloride is recovered by vacuum distillation. N,N-dimethylformamide at a mass of 4 times its mass is added to the remaining components after distillation. Triethylamine at a mass of 10 times its mass and triethylenetetramine at a mass of 1.5 times their mass are added dropwise under ice-water bath conditions. After stirring and reacting for 3 hours, the product components are filtered. The filter cake is washed alternately with ethanol and deionized water until the washing liquid is neutral, and then dried.

[0033] The preparation method of pretreated activated carbon is as follows: the cleaned and dried activated carbon is immersed in a 5wt% potassium permanganate solution, the pH is adjusted to 3.5 with dilute sulfuric acid, and the carbon is kept at 30℃ for 15h; then, after solid-liquid separation, water washing and drying, the pretreated activated carbon is obtained.

[0034] The specific steps for the initial activation are as follows: by weight, mix 40 parts of aminated activated carbon, 1.5 parts of tetramethylolmethane, 0.5 parts of tannic acid, 0.1 parts of citric acid, 0.2 parts of carotene alcohol, 3 parts of ethyl acetate, and 50 parts of ethanol aqueous solution with a volume concentration of 20%, and heat-treat at 40°C for 3 hours; then evaporate and dehydrate.

[0035] The specific steps for secondary activation are as follows: Mix the activated material obtained after the first activation with ammonium molybdate (4% by mass) and sodium tripolyphosphate (8% by mass) of aminated activated carbon, and heat-treat at 120°C for 35 minutes under nitrogen protection. Example 2

[0036] A preparation process for a chemical waste gas adsorbent includes the following steps:

[0037] Step 1: Under nitrogen protection, slowly add 0.9 times the volume of methyl acrylate and 2 times the volume of methanol to diethylenetriamine in an ice-water bath. After mixing and stirring evenly, react at room temperature for 5 hours. After the reaction is complete, recover the residual solvent in the product by vacuum distillation. Store the obtained reaction monomer for later use.

[0038] Step 2: Add the aminated activated carbon and the aminated composite substrate to 10 times their weight of the reaction monomers, mix well, react at 70°C for 3 hours, and then react at 85°C for 4 hours. Filter the reaction products, wash them five times with methanol, and vacuum dry them to obtain the modified activated carbon and the modified composite substrate, respectively. The composite substrate is graphene oxide loaded with nano-titanium dioxide.

[0039] Step 3: After the modified activated carbon is activated twice, it is added into a mixing device along with 8% nano-cerium oxide and 15% modified composite substrate by mass, and after mixing, the chemical waste gas adsorbent is obtained.

[0040] The preparation methods of the aminated composite substrate, composite substrate, aminated activated carbon, and pretreated activated carbon in this embodiment, as well as the two activation processes of the modified activated carbon and the selection of activated carbon, are the same as in Example 1. Example 3

[0041] A preparation process for a chemical waste gas adsorbent includes the following steps:

[0042] Step 1: Under nitrogen protection, slowly add 0.9 times the volume of methyl acrylate and 2.5 times the volume of methanol to diethylenetriamine in an ice-water bath. After mixing and stirring evenly, react at room temperature for 6 hours. After the reaction is complete, recover the residual solvent in the product by vacuum distillation. Store the obtained reaction monomer for later use.

[0043] Step 2: Add the aminated activated carbon and the aminated composite substrate to 15 times their weight of the reaction monomers, mix well, react at 75°C for 2 hours, and then react at 95°C for 3 hours. Filter the reaction products, wash them five times with methanol, and vacuum dry them to obtain the modified activated carbon and the modified composite substrate, respectively. The composite substrate is graphene oxide loaded with nano-titanium dioxide.

[0044] Step 3: After the modified activated carbon is activated twice, it is added to the mixing equipment along with 10% nano-cerium oxide and 20% modified composite substrate by weight, respectively. After mixing, the chemical waste gas adsorbent is obtained.

[0045] The preparation methods of the aminated composite substrate, composite substrate, aminated activated carbon, and pretreated activated carbon in this embodiment, as well as the two activation processes of the modified activated carbon and the selection of activated carbon, are the same as in Example 1.

[0046] Comparative Example 1: The difference between this comparative example and the embodiment is that a composite substrate is used instead of an equal amount of modified composite substrate in this comparative example.

[0047] Comparative Example 2: The difference between this comparative example and the embodiment is that graphene oxide is used instead of an equal amount of composite substrate in this comparative example.

[0048] Comparative Example 3: The difference between this comparative example and the embodiment is that nano-titanium dioxide is used instead of an equal amount of composite substrate in this comparative example.

[0049] Comparative Example 4: The difference between this comparative example and the embodiment is that activated carbon is used instead of an equal amount of modified activated carbon in this comparative example.

[0050] Comparative Example 5: The difference between this comparative example and the examples is that the modified activated carbon was not activated for the first time in this comparative example.

[0051] Comparative Example 6: The difference between this comparative example and the examples is that the modified activated carbon was not reactivated in this comparative example.

[0052] Adsorption performance testing methods and data

[0053] I. Testing Standards and Methods

[0054] 1. Adsorption capacity and breakthrough time (GB / T35239-2017)

[0055] Apparatus: 10mm inner diameter glass adsorption column, constant temperature 25℃

[0056] step:

[0057] (a) Fill with 0.5g of adsorbent;

[0058] (b) Introduce simulated exhaust gas (benzene: 500ppm, SO2: 300ppm, formaldehyde: 200ppm, flow rate 0.5L / min);

[0059] (c) Gas chromatography (GC-FID) was used to monitor the outlet concentration and record the breakthrough time (when the outlet concentration reached 5% of the inlet concentration).

[0060] (d) Calculation of adsorption capacity:

[0061] in,

[0062] m: Adsorbent mass (unit: g)

[0063] C0: Import concentration (unit: ppm)

[0064] C t : Outlet concentration (5% CO at breakthrough, unit: ppm)

[0065] V: Gas flow rate (L / min)

[0066] t: Penetration time (min)

[0067] 2. Heavy metal removal rate (EPA Method 29)

[0068] step:

[0069] (a) Introduce waste gas containing Hg vapor (50 μg / m³), Cd compounds (30 μg / m³), and Pb vapor (40 μg / m³);

[0070] (b) ICP-MS determination of inlet and outlet concentrations;

[0071] (c) Removal rate calculation: (C0 is the imported concentration, C) t (Export concentration).

[0072] 3. Regeneration performance

[0073] step:

[0074] (a) Nitrogen desorption at 120℃ for 2 hours (flow rate 1L / min);

[0075] (b) Repeat the adsorption-desorption cycle 5 times;

[0076] (c) Calculation of capacity retention rate: .

[0077] II. Adsorption performance data of each group of adsorbents

[0078]

[0079] By comparing and analyzing the relevant data in the table, it can be seen that this invention, through chemical grafting of adsorbents onto the surface of inorganic porous materials to adsorb macromolecular substances in industrial waste gas, combined with other functional treatment steps, prepares a chemical waste gas adsorbent with high adsorption capacity, high selectivity, good stability, and renewability. This achieves efficient adsorption and removal of multiple pollutants in chemical waste gas, effectively filling the technical deficiencies of existing adsorbents, improving the efficiency and quality of chemical waste gas treatment, and reducing environmental pollution. Therefore, this indicates that the preparation process of the chemical waste gas adsorbent provided by this invention has a broader market prospect and is more suitable for widespread application.

[0080] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0081] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A process for the preparation of a chemical waste gas adsorbent, characterized in that, It comprises the following steps: Step one, under the protection of nitrogen, slowly drop 0.85-0.9 times volume of methyl acrylate and 1.5-2.5 times volume of methanol into diethylenetriamine in an ice water bath environment, mix and stir uniformly, and then react at room temperature for 4-6 hours; after the reaction is completed, recover the residual solvent in the product by distillation under reduced pressure, and store the obtained reaction monomer for later use; Step two, respectively put the aminated activated carbon and the aminated composite substrate into 8-15 times mass of the reaction monomer, mix uniformly, first react at a temperature of 65-75 DEG C for 2-3 hours, then raise the temperature to 80-95 DEG C and react for 3-5 hours; sequentially filter, wash with methanol for 4-5 times, and vacuum dry the reaction product to obtain the modified activated carbon and the modified composite substrate respectively; wherein the composite substrate is graphene oxide loaded with nano titanium dioxide; Step three, activate the modified activated carbon twice; The specific steps of the first activation are as follows: mix 40-50 parts of the modified activated carbon, 1.5-2.5 parts of tetramethylolmethane, 0.5-0.8 parts of tannic acid, 0.1-0.3 parts of citric acid, 0.2-0.4 parts of carrot alcohol, 3-5 parts of ethyl acetate, and 50-75 parts of 20-40% volume concentration of ethanol aqueous solution, and heat treat at a temperature of 40-50 DEG C for 2-4 hours; then evaporate and dehydrate to obtain the activated material; The specific steps of the second activation are as follows: mix the activated material obtained after the first activation with 4-6% of ammonium molybdate and 8-12% of sodium tripolyphosphate based on the mass of the aminated activated carbon, and heat treat at a temperature of 120-140 DEG C for 25-35 minutes under the protection of nitrogen; After the modified activated carbon is activated twice, put it into a mixing device together with 6-10% of nano cerium oxide and 15-20% of the modified composite substrate based on the mass of the modified activated carbon, mix uniformly, and then obtain the chemical waste gas adsorbent.

2. The process for preparing a chemical waste gas adsorbent according to claim 1, characterized by, The preparation method of the aminated composite substrate is as follows: uniformly disperse 3-aminopropyltrimethoxysilane in 85-90% volume concentration of ethanol aqueous solution at a dosage of 0.1-0.2 g / mL, adjust the pH to 3.6-4.2 with formic acid, add 3-5 times mass of the composite substrate based on the mass of 3-aminopropyltrimethoxysilane, and stir and react at a temperature of 50-60 DEG C for 5-8 hours; after the reaction is completed, sequentially perform suction filtration, water washing, and drying treatment on the reaction product.

3. The process for preparing a chemical waste gas adsorbent according to claim 1, characterized by, The activated carbon is selected from any one of coconut shell activated carbon and apricot kernel shell activated carbon, and has a particle size of 2-4 mm.

4. The preparation process of the chemical waste gas adsorbent according to claim 1 or 2, characterized in that, The preparation method of the composite substrate is as follows: acetic acid, anhydrous ethanol and tetrabutyl titanate are mixed and stirred at a volume ratio of 0.15-0.25:1:4-6 for 40-60 min, then the obtained glue is added with a graphene oxide aqueous dispersion, and stirred at a speed of 300-500 r / min for 80-150 min; the obtained mixture is transferred into a microwave reaction instrument, treated at a power of 500 W for 50-80 min, and then dried and sintered to obtain the composite substrate; wherein the concentration of graphene oxide in the graphene oxide aqueous dispersion is 30-60 g / L, and the amount of graphene oxide is 5-8% of the mass of the glue.

5. The process for preparing a chemical waste gas adsorbent according to claim 4, characterized by: The drying temperature is 100-120 DEG C, and the drying time is 100-150 min.

6. The process for preparing a chemical waste gas adsorbent according to claim 4, characterized by, The sintering temperature is set to 400-480 DEG C, and the sintering time is set to 2-3 h.

7. The process for preparing a chemical waste gas adsorbent according to claim 1, characterized by, The preparation method of the aminated activated carbon is as follows: pretreated activated carbon is ultrasonically dispersed in thionyl chloride with a mass of 6-10 times that of the activated carbon, refluxed for 2-3 h, and then excess thionyl chloride is recovered by distillation under reduced pressure; N,N-dimethylformamide with a mass of 4-6 times that of the thionyl chloride is added to the remaining components after distillation, and triethylamine with a mass of 10-15 times that of the pretreated activated carbon and triethylenetetramine with a mass of 1.5-2 times that of the pretreated activated carbon are added dropwise under the condition of an ice water bath; after stirring for 3-5 h, the product components are suction filtered, the filter cake is washed with ethanol and deionized water alternately until the washing liquid is neutral, and then dried to obtain the aminated activated carbon.

8. The process for preparing a chemical waste gas adsorbent according to claim 7, characterized by, The preparation method of the pretreated activated carbon is as follows: the washed and dried activated carbon is immersed in a 5-10 wt% potassium permanganate solution, the pH is adjusted to 3.5-4 with dilute sulfuric acid, and the temperature is maintained at 30-40 DEG C for 10-15 h; then the solid-liquid separation, water washing and drying treatment are performed to obtain the pretreated activated carbon.

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