A nitrogen-doped graphene-activated carbon active adsorbent and preparation method thereof, a deodorizing device and application in the field of air purification

Abstract

The present invention belongs to the technical field of active adsorbents, and discloses a nitrogen-doped graphene-activated carbon active adsorbent and a preparation method thereof, a deodorizing device, and an application in the field of air purification. In the preparation method of the active adsorbent provided by the present invention, ethyleneamine is first used to perform amino modification reaction on activated carbon, which can effectively improve the mutual binding force between activated carbon and graphene oxide to increase the graphene oxide loading thereon, and then graphene oxide and ammonium salt are used to perform ultrasonic impregnation treatment and drying treatment on amino-modified activated carbon, and finally the adsorption precursor is subjected to high-temperature calcination treatment, and through the interaction of multiple modification steps, the active adsorbent finally prepared is coordinated to have excellent malodor gas adsorption capacity and adsorption capacity, and the active adsorbent can be well applied to the field of air purification, especially in the deodorization of kitchen waste.

Description

Technical Field

[0001] The present invention belongs to the technical field of active adsorbents, and in particular relates to a nitrogen-doped graphene-activated carbon active adsorbent and a preparation method thereof, a deodorizing device and application in the field of air purification. Background Art

[0002] In the process of storage and treatment, food waste will inevitably emit malodorous waste gas with comprehensive odor, which includes malodorous substances such as ammonia, hydrogen sulfide, methyl mercaptan, methyl sulfide and dimethyl disulfide.

[0003] At present, the methods for absorbing and treating malodorous waste gas include chemical degradation and physical adsorption. Chemical degradation is the catalytic degradation of malodorous gas by photocatalysts. When the light source is irradiated on the surface of the semiconductor catalyst, when the radiation energy is greater than the bandgap width (Eg = hC / λ max ), the electrons in the valence band (VB) of the semiconductor are excited to jump to the conduction band (CB), generating photogenerated electrons (e - ) and photogenerated holes (h + ); photogenerated holes react with -OH and H2O adsorbed on the catalyst surface to generate hydroxyl radicals, while photogenerated electrons react with O2 to generate singlet oxygen. Both of them have strong oxidizing properties and can oxidize and degrade malodorous pollutants to produce H2O, CO2, etc.; however, the photocatalyst used in chemical degradation is expensive and has a slow degradation rate, and is only suitable for odor treatment at low flow rates and low concentrations. Compared with chemical degradation, physical adsorption is the use of physical adsorbents such as activated carbon to adsorb and capture malodorous gases. The reagents used are widely available and inexpensive, suitable for the rapid treatment of malodorous gases, and therefore are more widely used. Among them, activated carbon is the most commonly used adsorbent in physical adsorption. It has the characteristics of large specific surface area and rich pore structure, and has a better adsorption effect on malodorous gases. However, due to the limited adsorption sites on the surface of activated carbon and the limited pore volume of the microporous structure, the adsorption capacity of activated carbon is greatly restricted, making it difficult to adsorb large amounts of gas. As a result, in actual use, the activated carbon needs to be frequently replaced or acid-washed for activation, resulting in problems such as short service life and secondary pollution, which has great limitations. Summary of the invention

[0004] The first object of the present invention is to provide a method for preparing an active adsorbent. In the preparation method, after the activated carbon is amino-modified by ethyleneamine, the obtained amino-modified activated carbon is mixed with graphene oxide and ammonium salt and calcined at high temperature, and the surface functional group composition and pore structure of the activated carbon are changed to form a microstructure that is conducive to the loading of graphene oxide, and the graphene oxide loading capacity of the activated carbon is expanded, so that the graphene oxide can be efficiently and stably dispersed in the pores of the activated carbon; and the ethyleneamine and ammonium salt can react with the functional groups on the activated carbon and / or graphene oxide during the preparation process, so that the obtained active adsorbent has abundant nitrogen-containing groups such as pyridinic nitrogen, pyrrolic nitrogen and graphite nitrogen, and the surface alkaline center is formed by the joint action of the above nitrogen-containing groups, and the obtained active adsorbent is combined with rich loaded graphene oxide to give the obtained active adsorbent excellent odor gas adsorption capacity and adsorption capacity, which can be well applied to the field of air purification, especially in the physical adsorption of odorous waste gas generated by kitchen garbage, and has good application prospects.

[0005] The second object of the present invention is to provide an active adsorbent.

[0006] A third object of the present invention is to provide a deodorizing device.

[0007] The fourth object of the present invention is to provide the use of the above-mentioned active adsorbent and / or deodorizing device in deodorizing kitchen waste.

[0008] Specifically, the preparation method of the active adsorbent provided by the present invention specifically includes: S1, taking activated carbon and ethyleneamine to carry out amino modification reaction to obtain amino-modified activated carbon; S2, taking the amino-modified activated carbon, mixing it with graphene oxide and ammonium salt, and carrying out ultrasonic impregnation treatment and drying treatment to obtain an adsorption precursor; S3, taking the adsorption precursor and carrying out high-temperature calcination treatment under a nitrogen atmosphere to obtain the active adsorbent.

[0009] Furthermore, in step S1, the activated carbon is columnar activated carbon, the diameter of the columnar activated carbon is 2 to 6 mm, and the average pore size is 1.5 to 2 nm.

[0010] Furthermore, in step S1, the ethyleneamine is selected from one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

[0011] Furthermore, in step S1, the added mass ratio of the activated carbon to ethyleneamine is 1:(0.01-0.5).

[0012] Furthermore, in step S1, the temperature of the amino modification reaction is 90-120° C., and the time is 1-4 hours.

[0013] Furthermore, in step S2, the average sheet diameter of the graphene oxide is 50 to 150 nm.

[0014] Furthermore, in step S2, the graphene oxide is high-pressure homogenized graphene oxide, and the preparation of the high-pressure homogenized graphene oxide includes: mixing a graphene oxide raw material with H2O to obtain a graphene oxide solution; and performing high-pressure homogenization treatment on the graphene oxide solution to obtain the high-pressure homogenized graphene oxide.

[0015] Furthermore, in step S2, the concentration of the graphene oxide solution is 0.1-1 wt%.

[0016] Furthermore, in step S2, the pressure of the high-pressure homogenization treatment is 12000-22000 psi, and the flow rate is 0.5-1.5 L / h.

[0017] Furthermore, in step S2, the ammonium salt is selected from one or more of ammonium chloride, ammonium carbonate and ammonium bicarbonate.

[0018] Furthermore, in step S2, the added mass ratio of the amino-modified activated carbon, graphene oxide and ammonium salt is 1:(0.001-0.01):(0.1-0.5).

[0019] Furthermore, in step S2, the temperature of the ultrasonic immersion treatment is not higher than 40° C., and the time is 1 to 6 hours.

[0020] Furthermore, in step S2, the drying process is carried out at a temperature of 50 to 170° C. and for a time of 6 to 24 hours.

[0021] Furthermore, in step S3, the heating rate of the high temperature calcination treatment is 2-10°C / min, the holding temperature is 700-1000°C, and the holding time is 1-4h.

[0022] The active adsorbent provided by the present invention is prepared by the above-mentioned method for preparing the active adsorbent.

[0023] The deodorant used in the deodorizing device provided by the present invention includes the above-mentioned active adsorbent.

[0024] The present invention also provides the application of the above-mentioned active adsorbent and / or deodorizing device in the field of air purification.

[0025] Beneficial effects:

[0026] The invention provides a method for preparing an active adsorbent. In the preparation method, ethyleneamine is first used to perform an amino modification reaction on activated carbon to change the functional group composition of the activated carbon, thereby obtaining amino-modified activated carbon, which has excellent binding and adsorption capabilities for graphene oxide; then, graphene oxide and ammonium salt are used to perform ultrasonic impregnation treatment and drying treatment on the amino-modified activated carbon, so that the graphene oxide and the ammonium salt can fully enter the pore structure of the amino-modified activated carbon, thereby obtaining an adsorption precursor; finally, the adsorption precursor is subjected to high-temperature calcination treatment, so that the amino-modified activated carbon, the graphene oxide and the ammonium salt react, so that the graphene oxide can be stably loaded, and rich nitrogen-containing groups such as pyridine nitrogen, pyrrole nitrogen and graphite nitrogen are formed, and the pore structure of the activated carbon is reconstructed and optimized, so as to finally obtain an active adsorbent with excellent odor gas adsorption capability and adsorption capacity.

[0027] In some specific embodiments, the graphene oxide is preferably high-pressure homogenized graphene oxide obtained through one or more high-pressure homogenization treatments. The high-pressure homogenized graphene oxide can better enter the pore structure of the amino-modified activated carbon and better achieve efficient composite of the two, thereby obtaining an active adsorbent with better malodorous gas adsorption ability and adsorption capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the process for preparing an active adsorbent provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0029] Based on a deep understanding of the problems existing in the application of existing activated carbon in the adsorption treatment of malodorous gases, the inventors of the present invention have found through in-depth and extensive research that the amino modification reaction of activated carbon with ethyleneamine can effectively improve the mutual binding force between activated carbon and graphene oxide to increase the loading amount of graphene oxide on it, and the ethyleneamine introduced on the activated carbon and the amino group converted from it can react with graphene oxide, ammonium salt and other substances under high-temperature calcination to form nitrogen-containing groups such as pyridine nitrogen, pyrrole nitrogen and graphite nitrogen. Through the interaction of multiple modification steps, they cooperate to give the active adsorbent excellent malodorous gas adsorption ability and adsorption capacity. Based on this, the technical solution of the present invention is obtained.

[0030] In the present invention, the preparation method of the active adsorbent specifically includes: S1, taking activated carbon and ethyleneamine to carry out amino modification reaction to obtain amino-modified activated carbon; S2, taking the amino-modified activated carbon, mixing it with graphene oxide and ammonium salt, and carrying out ultrasonic impregnation treatment and drying treatment to obtain an adsorption precursor; S3, taking the adsorption precursor and carrying out high-temperature calcination treatment under nitrogen atmosphere to obtain the active adsorbent.

[0031] In the present invention, the activated carbon is preferably columnar activated carbon, and the diameter of the columnar activated carbon is preferably 2 to 6 mm, such as 2, 2.1, 2.3, 2.5, 3, 4, 6 or any value therebetween; the average pore size is preferably 1.5 to 2 nm, such as 1.5 nm, 1.6 nm, 1.8 nm, 2 nm or any value therebetween. At this time, the activated carbon has excellent mechanical strength and rich pore structure, and has a relatively good graphene oxide loading capacity.

[0032] In the present invention, the ethyleneamine is preferably an acyclic linear polymer of ethylenediamine, which can react with the functional groups on the activated carbon, thereby introducing abundant amino groups or other nitrogen-containing functional groups on at least the activated carbon, so as to improve the adsorption and binding ability of the activated carbon for graphene oxide, give it a higher graphene oxide loading capacity, and can participate in the reaction in the subsequent high-temperature calcination to form nitrogen-containing groups such as pyridinic nitrogen, pyrrolic nitrogen and graphitic nitrogen.

[0033] In some specific embodiments, specific examples of the ethyleneamine include, but are not limited to, one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

[0034] In the present invention, in step S1, the added mass ratio of the activated carbon to ethyleneamine is preferably 1:(0.01-0.5), such as 1:0.01, 1:0.02, 1:0.04, 1:0.1, 1:0.3, 1:0.5 or any value therebetween. At this time, the ethyleneamine can fully modify the activated carbon, so that the amino groups on the activated carbon are evenly distributed, so that the graphene oxide on the finally prepared active adsorbent has a more ideal dispersion, thereby giving it a more ideal odor gas adsorption performance.

[0035] In the present invention, in step S1, the conditions of the amino modification reaction specifically include: the temperature is preferably 90-120°C, such as 90°C, 93°C, 98°C, 100°C, 105°C, 110°C, 120°C or any value therebetween; the time is preferably 1-4h, such as 1h, 1.05h, 1.1h, 1.3h, 1.7h, 1.9h, 2h, 2.5h, 3h, 4h or any value therebetween. At this time, the above-mentioned amino modification reaction conditions are conducive to achieving a better amino modification effect on the activated carbon, thereby obtaining an active adsorbent with better performance.

[0036] In the present invention, the average sheet diameter of the graphene oxide is preferably 50 to 150 nm, such as 60 nm,

[0037] 80nm, 100nm, 120nm, 150nm or any value therebetween. At this time, the graphene oxide can better enter the pore structure of the activated carbon, thereby achieving a better stable loading effect.

[0038] In the present invention, the graphene oxide is more preferably high-pressure homogenized graphene oxide, which refers to graphene oxide that has been treated with high-pressure homogenization. Compared with the original graphene oxide, the flake diameter is greatly reduced, which greatly improves its ability to enter the interior of the activated carbon, so that it can be stably dispersed in the pores of the activated carbon.

[0039] In the present invention, the preparation of the high-pressure homogenized graphene oxide specifically includes: mixing a graphene oxide raw material with H2O to obtain a graphene oxide solution; and subjecting the graphene oxide solution to high-pressure homogenization treatment to obtain the high-pressure homogenized graphene oxide.

[0040] In the present invention, the high-temperature homogenization treatment is a technical means commonly used in the existing preparation of graphene oxide. Those skilled in the art can make adaptive choices according to actual needs. The present invention does not impose special limitations on its specific steps and conditions.

[0041] In some specific embodiments, the concentration of the graphene oxide solution is preferably 0.1-1wt%, such as 0.1wt%, 0.2wt%, 0.35wt%, 0.4wt%, 0.6wt%, 0.9wt%, 1wt% or any value therebetween.

[0042] In some specific embodiments, the conditions of the high-pressure homogenization treatment specifically include a pressure of preferably 12000-22000psi, such as 12000psi, 14000psi, 16000psi, 18000psi, 20000psi, 22000psi or any value therebetween; a flow rate of preferably 0.5-1.5L / h, such as 0.6L / h, 0.8L / h, 1.0L / h, 1.2L / h, 1.5L / h or any value therebetween.

[0043] In the present invention, the ammonium salt is a compound composed of ammonium ions and acid ions, has good thermal decomposition ability, can be thermally decomposed during high-temperature calcination treatment, form more porous structures inside the activated carbon, and can react with functional groups on activated carbon and graphene oxide to convert nitrogen-containing groups such as pyridinic nitrogen, pyrrolic nitrogen and graphitic nitrogen to form abundant surface alkaline centers, giving the final active adsorbent both excellent specific surface area and malodorous gas adsorption capacity.

[0044] In some specific embodiments, specific examples of the ammonium salt include but are not limited to: one or more of ammonium chloride, ammonium carbonate and ammonium bicarbonate.

[0045] In the present invention, in step S2, the added mass ratio of the amino-modified activated carbon, graphene oxide and ammonium salt is preferably 1:(0.001-0.01):(0.1-0.5), such as 1:0.001:0.1, 1:0.005:0.1, 1:0.01:0.1, 1:0.001:0.3, 1:0.01:0.5 or any value therebetween. At this time, the graphene oxide and ammonium salt can fully modify the amino-modified activated carbon, thereby giving the finally prepared active adsorbent a more ideal odor gas adsorption performance.

[0046] In the present invention, in step S2, the conditions of the ultrasonic immersion treatment specifically include: the temperature is preferably not higher than 40°C, more preferably 20-35°C, such as 20°C, 20.8°C, 23°C, 25°C, 30°C, 31°C, 35°C or any value therebetween; the time is preferably 1-6h, such as 1h, 1.1h, 1.3h, 1.6h, 2h, 3h, 4h, 5h, 6h or any value therebetween. At this time, the use of the above-mentioned ultrasonic immersion treatment conditions can enable graphene oxide to fully enter the pore structure of the amino-modified activated carbon to achieve a more ideal graphene oxide loading effect.

[0047] In the present invention, in step S2, the drying conditions specifically include: the temperature is preferably 50-170°C, such as 50°C, 55°C, 58°C, 60°C, 80°C, 100°C, 120°C, 150°C, 170°C or any value therebetween; the time is preferably 6-24h, such as 6h, 6.5h, 7h, 9h, 10h, 12h, 18h, 24h or any value therebetween. At this time, the above drying conditions can achieve sufficient drying, and can make the amino-modified activated carbon and graphene oxide better combined, thereby improving the loading stability of graphene oxide.

[0048] In the present invention, in step S3, the conditions of the high temperature calcination treatment include: the heating rate is preferably 2 to 10°C / min, such as 2°C / min, 2.5°C / min, 3°C / min, 4°C / min, 5°C / min, 8°C / min, 10°C / min or any value therebetween; the insulation temperature is preferably 700 to 1000°C, such as 700°C, 750°C, 780°C, 800°C, 900°C, 1000°C or any value therebetween; the insulation time is preferably 1 to 4h, such as 1h, 1.2h, 1.5h, 2h, 3h, 3.5h, 4h or any value therebetween. At this time, the above-mentioned high temperature calcination treatment conditions can make the graphene oxide and the activated carbon better combined, which is conducive to the formation of nitrogen-containing groups such as pyridinic nitrogen, pyrrolic nitrogen and graphitic nitrogen, thereby obtaining an active adsorbent with excellent specific surface area and odor gas adsorption capacity.

[0049] The present invention also provides an active adsorbent, which is prepared by the above-mentioned active adsorbent preparation method. The active adsorbent has a rich pore structure and a specific surface area of ​​900-1100m 2 / g, and it is rich in nitrogen-containing groups such as pyridinic nitrogen, pyrrolic nitrogen and graphitic nitrogen, which have excellent adsorption ability and capacity for gases, especially the adsorption effect of malodorous waste gas generated by kitchen garbage has been significantly improved.

[0050] The present invention also provides a deodorizing device, in which the deodorant used includes the above-mentioned active adsorbent, which can be used to treat malodorous substances in the environment. It is a type of device commonly used in the prior art, and the present invention has no special limitation on its specific structure.

[0051] The present invention also provides the use of the above-mentioned active adsorbent and / or deodorizing device in the field of air purification, especially in the physical adsorption of malodorous waste gas generated by kitchen garbage.

[0052] Embodiments of the present invention are described in detail below, and the examples of the embodiments are intended to be used to explain the present invention, but should not be construed as limiting the present invention. In the embodiments, if specific techniques or conditions are not specified, the techniques or conditions described in the literature in this area or the product specifications are used. If the manufacturer is not specified for reagents or instruments used, they are all conventional products that can be obtained commercially.

[0053] The reagents and sources involved in the following preparation examples and embodiments include:

[0054] Pillared activated carbon (Shijiazhuang Hongsen Activated Carbon Co., Ltd., diameter 4 mm, average pore size 1.5-2 nm);

[0055] Graphene oxide (Xiamen Siyan New Material Technology Co., Ltd., product number SY-GO-L, average flake diameter 50-150 nm).

[0056] Preparation Example 1

[0057] This preparation example is used to illustrate the preparation of a high-pressure homogenized graphene oxide solution, specifically comprising: uniformly dispersing a graphene oxide raw material and H2O by ultrasonic dispersion (ultrasonic dispersion frequency is 40KHz, temperature is 30°C, and time is 60min) to obtain a graphene oxide solution with a concentration of 0.1wt%, and performing high-pressure homogenization treatment on the graphene oxide solution at 15000psi and 1.0L / h for 3 times to obtain a high-pressure homogenized graphene oxide solution.

[0058] Preparation Example 2

[0059] This preparation example adopts the method provided in Preparation Example 2 to prepare a high-pressure homogeneous graphene oxide solution, except that the concentration of the graphene oxide solution is 0.5wt%, and other conditions are the same to obtain a graphene oxide solution.

[0060] Example 1

[0061] This example is used to illustrate the preparation of an active adsorbent. Figure 1 , specifically including:

[0062] S1. Mix the columnar activated carbon and a 5 wt% triethylenetetramine (TETA) solution in a mass ratio of 1:2, carry out amino modification reaction in a 90° C. water bath for 2 h, filter and wash to neutrality to obtain amino-modified activated carbon.

[0063] S2. Mix the amino-modified activated carbon, the high-pressure homogenized graphene oxide solution provided in Preparation Example 1 and ammonium chloride in a mass ratio of 1:2:0.2, and perform ultrasonic impregnation treatment on the obtained mixed solution at a temperature of 40°C and an ultrasonic dispersion frequency of 40 kHz for 4 hours. Then, place the mixed solution after ultrasonic impregnation treatment in an oven at 80°C for drying for 12 hours to obtain an adsorption precursor.

[0064] S3. The adsorption precursor is placed in a tubular furnace, heated to 700°C at a heating rate of 5°C / min under a nitrogen atmosphere, and then kept at this temperature for 2 hours for high-temperature calcination to obtain an active adsorbent.

[0065] Example 2

[0066] This example adopts the method provided in Example 1 to prepare an active adsorbent, except that in step S1, the concentration of the TETA solution is 10 wt %, and other conditions are the same to obtain an active adsorbent.

[0067] Example 3

[0068] This example adopts the method provided in Example 1 to prepare an active adsorbent, except that in step S1, the concentration of the TETA solution is 20 wt %, and other conditions are the same to obtain an active adsorbent.

[0069] Example 4

[0070] This embodiment adopts the method provided in Example 1 to prepare the active adsorbent, except that in step S1, an equal mass of 5wt% diethylenetriamine solution is used instead of 5wt% TETA solution, and other conditions are the same to obtain the active adsorbent.

[0071] Example 5

[0072] This embodiment adopts the method provided in Example 1 to prepare the active adsorbent, except that in step S1, an equal mass of 5wt% tetraethylenepentamine solution is used instead of 5wt% TETA solution, and other conditions are the same to obtain the active adsorbent.

[0073] Example 6

[0074] This example adopts the method provided in Example 1 to prepare an active adsorbent, except that in step S1, an equal mass of a 5wt% piperazine solution is used instead of a 5wt% TETA solution, and other conditions are the same to obtain an active adsorbent.

[0075] Example 7

[0076] This example adopts the method provided in Example 1 to prepare an active adsorbent, except that in step S1, the temperature of the amino modification reaction is 110° C. and the time is 4 h. Other conditions are the same to obtain an active adsorbent.

[0077] Example 8

[0078] This example adopts the method provided in Example 1 to prepare an active adsorbent, except that in step S1, the temperature of the amino modification reaction is 120° C. and the time is 2 h. Other conditions are the same to obtain an active adsorbent.

[0079] Example 9

[0080] This example adopts the method provided in Example 1 to prepare an active adsorbent, except that, in step S1, an equal mass of the high-pressure homogenized graphene oxide solution provided in Preparation Example 2 is used instead of the high-pressure homogenized graphene oxide solution provided in Preparation Example 1, and other conditions are the same to obtain an active adsorbent.

[0081] Example 10

[0082] This example adopts the method provided in Example 1 to prepare the active adsorbent, except that, in step S2, an equal mass of a 0.1wt% graphene oxide solution (obtained in Preparation Example 1) is used instead of the high-pressure homogenized graphene oxide solution provided in Preparation Example 1, that is, the graphene oxide solution in Preparation Example 1 that has not been subjected to high-pressure homogenization is directly used as a raw material to prepare the active adsorbent, and other conditions are the same to obtain an active adsorbent.

[0083] Embodiment 11

[0084] This example adopts the method provided in Example 1 to prepare an active adsorbent, except that in step S2, the mass ratio of amino-modified activated carbon, high-pressure homogenized graphene oxide solution and ammonium chloride is 1:2:0.4, and other conditions are the same to obtain an active adsorbent.

[0085] Example 12

[0086] This example adopts the method provided in Example 1 to prepare an active adsorbent, except that in step S2, the mass ratio of amino-modified activated carbon, high-pressure homogenized graphene oxide solution and ammonium chloride is 1:2:0.6, and other conditions are the same to obtain an active adsorbent.

[0087] Embodiment 13

[0088] This embodiment adopts the method provided in Embodiment 5 to prepare the active adsorbent, except that in step S3, the holding temperature of the high temperature calcination treatment is 800° C., and other conditions are the same to obtain the active adsorbent.

[0089] Embodiment 14

[0090] This embodiment adopts the method provided in Embodiment 5 to prepare the active adsorbent, except that in step S3, the holding temperature of the high temperature calcination treatment is 900° C., and other conditions are the same to obtain the active adsorbent.

[0091] Comparative Example 1

[0092] This comparative example is used to illustrate the preparation of a comparative adsorbent, which specifically includes:

[0093] (1) Mixing columnar activated carbon, the high-pressure homogenized graphene oxide solution provided in Preparation Example 1 and ammonium chloride in a mass ratio of 1:2:0.2 to obtain a mixed solution; subjecting the obtained mixed solution to ultrasonic impregnation treatment for 4 h at a temperature of 40° C. and an ultrasonic dispersion frequency of 40 kHz; and then placing the mixed solution subjected to ultrasonic impregnation treatment in an oven at 80° C. for drying for 12 h to obtain an adsorption precursor.

[0094] (2) The adsorption precursor was placed in a tubular furnace, heated to 700°C at a heating rate of 5°C / min under a nitrogen atmosphere, and then kept at that temperature for 2 hours for high-temperature calcination treatment to obtain a comparative adsorbent.

[0095] Comparative Example 2

[0096] This comparative example adopts the method provided in Example 1 to prepare a comparative adsorbent, except that, in step S1, an equal mass of 5wt% ammonia water is used to replace the 5wt% TETA solution, and other conditions are the same to obtain a comparative adsorbent.

[0097] Comparative Example 3

[0098] This comparative example adopts the method provided in Example 1 to prepare a comparative adsorbent, except that in step S2, an equal mass of H2O is used to replace the high-pressure homogenized graphene oxide solution provided in Preparation Example 1, and other conditions are the same to obtain a comparative adsorbent.

[0099] Comparative Example 4

[0100] This comparative example adopts the method provided in Example 1 to prepare a comparative adsorbent, except that in step S2, an equal mass of amino-modified activated carbon (the product obtained in step S1 of Example 1) is used to replace ammonium chloride, and other conditions are the same to obtain a comparative adsorbent.

[0101] Test Case

[0102] This test example is used to illustrate the relevant performance of the active adsorbent provided in the above embodiment and the comparative adsorbent provided in the comparative example, with columnar activated carbon as a control, and the detection method and detection conditions used for the columnar activated carbon and each active adsorbent and comparative adsorbent are consistent, specifically including:

[0103] (1) Specific surface area: The specific surface area of ​​the active adsorbent and the comparative adsorbent was determined by the BET method. The test results are shown in Table 1.

[0104] (2) Odor gas adsorption capacity: According to the "Odor Pollutant Emission Standard GB14554-93", the OU value of odor gas (including ammonia, hydrogen sulfide, methyl mercaptan and other substances) before and after 24 hours of adsorption by active adsorbent / comparison adsorbent was measured by using an odor electronic nose, and the adsorption rate was calculated according to the following formula. The results are shown in Table 1.

[0105] Adsorption rate = (X1-X2) / X1×100%

[0106] Among them, X1 is the OU value before adsorption, and X2 is the OU value after adsorption by columnar activated carbon, activated adsorbent or reference adsorbent for 24 h.

[0107] Table 1.

[0108]

[0109] It can be seen from the test results shown in Table 1 that, compared with the columnar activated carbon and the comparative adsorbent provided by Comparative Examples 1 to 4, the active adsorbent provided by Examples 1 to 14 of the present invention has a significantly increased specific surface area, a rich pore structure, can provide a larger space for the adsorption of gas, and has excellent adsorption capacity; at the same time, the active adsorbent has abundant nitrogen-containing groups such as pyridine nitrogen, pyrrole nitrogen and graphite nitrogen, and has a good binding ability for malodorous gas substances such as ammonia, hydrogen sulfide, and methyl mercaptan. The adsorption rate is greater than 70%, and can reach up to 95%. It has very excellent adsorption capacity and can be well applied to the field of air purification, especially in the deodorization of kitchen waste, and has good application prospects.

[0110] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention.

Claims

1. A method for preparing an active adsorbent, characterized in that: The preparation method comprises: S1, taking activated carbon and ethyleneamine to carry out amino modification reaction to obtain amino-modified activated carbon; S2, mixing the amino-modified activated carbon with high-pressure homogenized graphene oxide and ammonium salt, performing ultrasonic impregnation treatment and drying treatment to obtain an adsorption precursor; S3, taking the adsorption precursor and subjecting it to high temperature calcination treatment under a nitrogen atmosphere to obtain the active adsorbent; The preparation of the high-pressure homogenized graphene oxide comprises: mixing a graphene oxide raw material with H2O to obtain a graphene oxide solution; and subjecting the graphene oxide solution to high-pressure homogenization to obtain the high-pressure homogenized graphene oxide.

2. The method for preparing an active adsorbent according to claim 1, characterized in that: In step S1, the activated carbon is columnar activated carbon.

3. The method for preparing an active adsorbent according to claim 2, characterized in that: The diameter of the columnar activated carbon is 2-6 mm, and the average pore size is 1.5-2 nm.

4. The method for preparing an active adsorbent according to claim 1, characterized in that: In step S1, the ethyleneamine is selected from one or more of diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.

5. The method for preparing an active adsorbent according to claim 1, characterized in that: In step S1, the added mass ratio of the activated carbon to ethyleneamine is 1:(0.01-0.5).

6. The method for preparing an active adsorbent according to claim 1, characterized in that: In step S1, the temperature of the amino modification reaction is 90-120° C. and the time is 1-4 hours.

7. The method for preparing an active adsorbent according to claim 1, characterized in that: In step S2, the average sheet diameter of the high-pressure homogenized graphene oxide is 50 to 150 nm.

8. The method for preparing an active adsorbent according to claim 1, characterized in that: In the preparation of the high-pressure homogenized graphene oxide, the concentration of the graphene oxide solution is 0.1-1 wt%.

9. The method for preparing an active adsorbent according to claim 1, characterized in that: In the preparation of the high-pressure homogenized graphene oxide, the pressure of the high-pressure homogenization treatment is 12000-22000psi, and the flow rate is 0.5-1.5L / h.

10. The method for preparing an active adsorbent according to claim 1, characterized in that: In step S2, the ammonium salt is selected from one or more of ammonium chloride, ammonium carbonate and ammonium bicarbonate.

11. The method for preparing an active adsorbent according to claim 1, characterized in that: In step S2, the added mass ratio of the amino-modified activated carbon, graphene oxide and ammonium salt is 1:(0.001-0.01):(0.1-0.5).

12. The method for preparing an active adsorbent according to claim 1, characterized in that: In step S2, the temperature of the ultrasonic immersion treatment is not higher than 40°C, and the time is 1 to 6 hours.

13. The method for preparing an active adsorbent according to claim 1, characterized in that: In step S2, the drying process is carried out at a temperature of 50 to 170°C and for a time of 6 to 24 hours.

14. The method for preparing an active adsorbent according to claim 1, characterized in that: In step S3, the heating rate of the high temperature calcination treatment is 2-10°C / min, the insulation temperature is 700-1000°C, and the insulation time is 1-4h.

15. An active adsorbent, characterized in that: The active adsorbent is prepared by the method for preparing the active adsorbent according to any one of claims 1 to 14.

16. A deodorizing device, characterized in that: The deodorant used in the deodorizing device includes the active adsorbent according to claim 15.

17. Use of the active adsorbent according to claim 15 and / or the deodorizing device according to claim 16 in the field of air purification.

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