A lotus-shaped carbon-aluminum composite hierarchical porous material based on aluminum smelting waste residue and a preparation method and application thereof

Abstract

The application discloses a lotus-shaped carbon-aluminum composite multi-level pore material based on aluminum smelting waste residues and a preparation method and application thereof, and the resource nature of aluminum smelting waste residues and organic waste can be utilized to harmlessly treat and high-value utilize inorganic and organic pollutants, and efficient clean conversion of synergistic pollution reduction and carbon reduction is obtained; the design of the carbon-aluminum composite multi-level pore material not only has a catalytic cracking effect on VOCs, but also can provide high-calorific-value fuel for combustion and heat storage in the VOCs combustion process, and heat efficiency is improved; the lotus-shaped material design can increase the diffusion area of VOCs and oxygen input, and make VOCs and oxygen fully contact with solid phases and active sites. The heat efficiency of the method reaches more than 90%, and the volatile organic pollutant removal rate is greater than 99%.

Description

TECHNICAL FIELD

[0001] The recycling of aluminum smelting waste belongs to the technical field, and particularly relates to a lotus-shaped carbon-aluminum composite multi-level pore material based on aluminum smelting waste and a preparation method and application thereof. BACKGROUND

[0002] In addition to containing aluminum oxide, industrial waste aluminum smelting waste is also rich in active elements such as calcium, iron, potassium and silicon, and has complex and diverse components, and is polluting, resourceful and social, and if not properly handled, will pollute the environment, affect environmental health, waste resources, damage production and life safety, and seriously affect life and health. Aluminum oxide has certain heat storage function, and calcium, iron and potassium have catalytic function and certain catalytic effect on volatile organic pollutants. At present, the aluminum smelting waste is proposed to be harmless, materialized and energyized, but no application technology for disposing volatile organic pollutants is proposed.

[0003] Volatile organic pollutants (Volatile Organic Compounds, VOCs) include benzene series, organic chlorides, freon series, organic ketones, amines, alcohols, ethers, esters, acids and petroleum hydrocarbon compounds with boiling points of 50-250 DEG C. A kind of organic matter in the form of vapor at room temperature is volatile organic compound. Usually, molecular sieve catalysis is used to convert it into flammable small molecule gas for combustion. However, VOCs are low in content in gas phase and in low heat value flue gas, and are difficult to burn. Generally, the method of heat storage combustion is used for oxygen-enriched combustion. However, there are still problems of low heat storage efficiency, high energy consumption, low catalytic conversion efficiency and expensive catalyst. SUMMARY

[0004] This section aims to summarize some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification to avoid obscuring the purpose of this section, abstract and title, and such simplifications or omissions cannot be used to limit the scope of the present application.

[0005] In view of the above and / or problems existing in the prior art, the present application is proposed.

[0006] Therefore, the purpose of the present application is to overcome the deficiencies in the prior art, and to provide a preparation method of lotus-shaped carbon-aluminum composite multi-level pore material based on aluminum smelting waste.

[0007] To solve the above technical problems, the present application provides the following technical solutions: including,

[0008] The aluminum smelting waste is baked and activated at 500-700 DEG C after pickling to obtain porous aluminum smelting waste;

[0009] The biomass is baked and treated, and then mixed with porous aluminum smelting waste residues to be pyrolyzed to obtain a carbon-aluminum composite material.

[0010] The carbon-aluminum composite material is activated by coupling CO2 and H2O, and then active components Ni and Fe are loaded by a dipping method to obtain an activated composite multi-level pore material.

[0011] The composite multi-level pore material is pressure-formed in a lotus-shaped mold to obtain a lotus-shaped carbon-aluminum composite multi-level pore particle material.

[0012] As a preferred scheme of the preparation method of the lotus-shaped carbon-aluminum composite multi-level pore material based on aluminum smelting waste residues, the acid pickling is performed by using 0-8 mol / L organic acid at 50-150 ℃ for 30 min, wherein the organic acid includes one of acetic acid, phenol and benzoic acid.

[0013] As a preferred scheme of the preparation method of the lotus-shaped carbon-aluminum composite multi-level pore material based on aluminum smelting waste residues, the treatment temperature of the biomass baking treatment is 220-300 ℃, and the treatment time is 20-60 min.

[0014] As a preferred scheme of the preparation method of the lotus-shaped carbon-aluminum composite multi-level pore material based on aluminum smelting waste residues, the mixing ratio of the biomass and the porous aluminum smelting waste residues for pyrolysis is 1:1, wherein the biomass is poplar sawdust, the pyrolysis temperature is 600-800 ℃, and the pyrolysis time is 30-60 min.

[0015] As a preferred scheme of the preparation method of the lotus-shaped carbon-aluminum composite multi-level pore material based on aluminum smelting waste residues, the carbon-aluminum composite material is activated by coupling CO2 and H2O, wherein the activation temperature is 800-1100 ℃, the CO2 flow rate is 50-100 mL / min, and the H2O flow rate is 0.5-2 g / min.

[0016] As a preferred scheme of the preparation method of the lotus-shaped carbon-aluminum composite multi-level pore material based on aluminum smelting waste residues, the mass fraction of the active component Ni is 6-10%, and the mass fraction of Fe is 1-4%.

[0017] Another object of the present application is to provide a lotus-shaped carbon-aluminum composite multi-level pore material based on aluminum smelting waste residues.

[0018] Another object of the present application is to provide an application of the lotus-shaped carbon-aluminum composite multi-level pore material based on aluminum smelting waste residues in catalytic degradation of volatile organic pollutants.

[0019] As a preferred scheme of the preparation method of the lotus-shaped carbon-aluminum composite multi-level pore material based on aluminum smelting waste residue, the method comprises the following steps: heating the lotus-shaped carbon-aluminum composite multi-level pore material to 900 DEG C, and then introducing oxygen and volatile organic pollutants to realize catalytic degradation, wherein the flow rate of the introduced oxygen is 150 ml / min.

[0020] As a preferred scheme of the preparation method of the lotus-shaped carbon-aluminum composite multi-level pore material based on aluminum smelting waste residue, the method comprises the following steps: heating the lotus-shaped carbon-aluminum composite multi-level pore material to 900 DEG C, and then introducing oxygen and volatile organic pollutants to realize catalytic degradation, wherein the flow rate of the introduced oxygen is 150 ml / min.

[0021] The present application has the following beneficial effects:

[0022] The present application provides a method for disposing volatile organic pollutants by using aluminum smelting waste residue. The resource of the aluminum smelting waste residue and the organic waste can be used to harmlessly treat and high-value utilize inorganic and organic pollutants, and obtain efficient and clean conversion of synergistic pollution reduction and carbon reduction. The design of the carbon-aluminum composite multi-level pore material not only has the effect of catalytic cracking of VOCs, but also can provide high-calorific-value fuel for combustion and heat storage in the VOCs combustion process, thereby improving the thermal efficiency. The lotus-shaped material design can increase the diffusion area of VOCs and oxygen input, so as to make VOCs and oxygen fully contact with solid phase and active sites. The thermal efficiency of the method is more than 90%, and the removal rate of volatile organic pollutants is greater than 99%. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. Among them:

[0024] Figure 1 It is a micro-morphology comparison diagram of the composite multi-level pore material (c), the carbon-aluminum composite material (b) and the biochar (a) in the embodiment 1 of the present application.

[0025] Figure 2 It is a solid carbon nuclear magnetic resonance spectrum diagram of the carbon-aluminum composite material in the embodiment 1 of the present application. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation manner of the present application will be described in detail in combination with the embodiment of the specification.

[0027] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be practiced without the specific details set forth in this description. In other instances, well-known methods have not been described in detail in order to avoid obscuring the present application. Therefore, the present application is not intended to be limited by the specific embodiments disclosed below, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0028] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. "In one embodiment" appearing in different places in the specification does not mean the same embodiment, nor is it an embodiment that is independent or alternative to other embodiments.

[0029] The aluminum refining waste residue used in the present application is from an aluminum material processing plant in Jiangsu Province, and the composition is Al2O3 83%, SiO2 7%, Fe2O3 2%, CaO 1%, MgO 3%, Na2O 1%, K2O 1%, CuO 0.5%, ZnO 0.5%, and other impurities;

[0030] The poplar sawdust used in the present application is from a wood processing plant in the south of Anhui Province, and the composition is cellulose content 42%, hemicellulose content 24%, and lignin content 25%;

[0031] The rest of the raw materials have no special description and are ordinary commercially available in the art.

[0032] The method for applying the lotus-shaped carbon-aluminum composite multi-level pore material to catalytic degradation of volatile organic pollutants in the present application is as follows:

[0033] The lotus-shaped carbon-aluminum composite multi-level pore material is first heated to 900℃, and then oxygen (150mL / min) and VOCs are introduced. The combustion of carbon can stabilize the heat at 900℃, and the thermal efficiency and the removal rate of volatile organic pollutants VOCs are determined;

[0034] Among them, the thermal efficiency = the energy consumption used for removing VOCs / the total energy consumption provided by the fuel;

[0035] VOCs removal rate = the amount of VOCs in the gas after the reaction / the amount of VOCs in the gas before the reaction.

[0036] Example 1

[0037] The present embodiment provides a lotus-shaped carbon-aluminum composite multi-level pore material based on aluminum refining waste residue and a preparation method thereof, specifically;

[0038] 1) The aluminum refining waste residue is mixed with 4mol / L acetic acid, and heat activated at 100℃ for 30min, and then baked at 550℃ for 2h to obtain porous aluminum refining waste residue;

[0039] 2) Poplar sawdust after 260℃ roasting treatment and porous aluminum smelting waste residue 1:1 mixed pyrolysis through pyrolysis reactor, nitrogen gas as protective gas, carrier gas flow rate is 90ml / min, temperature rising rate is 10℃ / min, heating to 700℃, pyrolysis heating keeps 30min, produces pyrolysis gas, pyrolysis tar, pyrolysis water and carbon-aluminum composite material, at this time, the specific surface area of carbon-aluminum composite material is 100m 2 / g, average pore size is 12nm, the micro-morphology contrast chart of biochar is as shown in Figure 1 Figure 1 (b) is the micro-morphology chart of carbon-aluminum composite material, Figure 1 (a) is the micro-morphology chart of biochar, the solid carbon nuclear magnetic resonance chart of carbon-aluminum composite material is as shown in Figure 2 , through the ecological risk assessment by standard GB 5085.1-7-2007 series method, it can be known that the heavy metals in carbon-aluminum composite material can be effectively fixed;

[0040] 3) Carbon-aluminum composite material is activated by CO2 coupling H2O at 900℃, CO2 flow rate is 90mL / min, H2O flow rate is 1g / min, then active components Ni and Fe are loaded by impregnation method, mass fraction of Ni is 10%, mass fraction of Fe is 4%, activated composite hierarchical porous material is obtained, the micro-morphology is as shown in Figure 1 (c);

[0041] 4) Composite hierarchical porous material is pressure formed in lotus-shaped mold, lotus-shaped carbon-aluminum composite hierarchical porous material is obtained, specific surface area reaches 256m 2 / g.

[0042] Comparative Example 1

[0043] The difference between this comparative example and Example 1 is that step 3) is omitted, CO2 coupling H2O activation is not used, and active components are not loaded, the carbon-aluminum composite material obtained in step 2) is directly placed in lotus-shaped mold for processing, and the rest of the process parameters are the same as those of Example 1, and the composite material of this comparative example is obtained.

[0044] Comparative Example 2

[0045] The difference between this comparative example and Example 1 is that the acidification step in step 1) is omitted, and the rest of the process parameters are the same as those of Example 1, which are as follows:

[0046] 1) Aluminum smelting waste residue is baked at 550℃ for 2h to obtain porous aluminum smelting waste residue;

[0047] ​2) Poplar sawdust after 260℃ baking treatment and porous aluminum smelting waste 1:1 mixed pyrolysis reactor pyrolysis, nitrogen is introduced as a protective gas, the carrier gas flow rate is 90ml / min, the temperature is raised to 700℃ at a rate of 10℃ / min, the pyrolysis heating is kept for 30min, the pyrolysis gas, pyrolysis tar, pyrolysis water and carbon-aluminum composite material are generated, at this time, the specific surface area of the carbon-aluminum composite material is 70m 2 / g, the average pore size is 12nm, and the ecological risk evaluation by the standard GB 5085.1-7-2007 series method shows that the heavy metals in the carbon-aluminum composite material can be effectively fixed;

[0048] 3) The carbon-aluminum composite material is activated by CO2 coupling H2O at 900℃, the CO2 flow rate is 90mL / min, the H2O flow rate is 1g / min, the active components Ni and Fe are loaded by impregnation method, the mass fraction of Ni is 10%, the mass fraction of Fe is 4%, and the activated composite hierarchical porous material is obtained;

[0049] 4) The composite hierarchical porous material is pressure-formed in a lotus-shaped mold to obtain a lotus-shaped carbon-aluminum composite hierarchical porous material, and the specific surface area reaches 125m 2 / g.

[0050] Comparative Example 3

[0051] The difference between this comparative example and Example 1 is that the step 2) is adjusted, the poplar sawdust is not subjected to 260℃ baking treatment, and is directly mixed with the aluminum smelting waste, which is as follows:

[0052] 1) The aluminum smelting waste is mixed with 4mol / L acetic acid, and is heat-activated at 100℃, and then is baked at 550℃ for 2h to obtain porous aluminum smelting waste;

[0053] 2) The poplar sawdust is mixed with the porous aluminum smelting waste at a ratio of 1:1 to pass through a pyrolysis reactor for pyrolysis, nitrogen is introduced as a protective gas, the carrier gas flow rate is 90ml / min, the temperature is raised to 700℃ at a rate of 10℃ / min, the pyrolysis heating is kept for 30min, the pyrolysis gas, pyrolysis tar, pyrolysis water and carbon-aluminum composite material are generated, at this time, the specific surface area of the carbon-aluminum composite material is 93m 2 / g, the average pore size is 11nm, and the ecological risk evaluation by the standard GB 5085.1-7-2007 series method shows that the heavy metals in the carbon-aluminum composite material can be effectively fixed;

[0054] 3) The carbon-aluminum composite material is activated by CO2 coupling H2O at 900℃, the flow rate of CO2 is 90 mL / min, the flow rate of H2O is 1 g / min, and then the activated composite material is loaded with active components Ni and Fe by impregnation method, the mass fraction of Ni is 10%, and the mass fraction of Fe is 4%, to obtain the activated composite material with multiple levels of pores;

[0055] 4) The composite material with multiple levels of pores is formed into a lotus-shaped carbon-aluminum composite material with multiple levels of pores by pressure molding in a lotus-shaped mold, and the specific surface area of the lotus-shaped carbon-aluminum composite material with multiple levels of pores reaches 235 m 2 / g.

[0056] The lotus-shaped carbon-aluminum composite material with multiple levels of pores in Example 1 and Comparative Examples 1-3 is applied to catalytic degradation of VOCs, and the thermal efficiency in the reaction and the removal rate of volatile organic pollutants are measured, and the results are shown in Table 1.

[0057] Table 1

[0058]

[0059] As can be seen from Table 1, the baking treatment, pickling of aluminum refining waste residue and activation of carbon-aluminum composite material involved in the steps of the present application all increase the thermal efficiency and removal rate of VOCs treatment, because there is a synergistic effect between the steps of the present application.

[0060] The pickling treatment in step 1) can remove impurities and harmful substances in the aluminum refining waste residue, improve the purity and activity of the waste residue, and the baking and activation process promotes the structural reorganization and activation of the waste residue through high-temperature treatment to form a porous structure, and the synergistic effect of the two steps can improve the purity, activity and pore structure of the waste residue, increase the adsorption and catalytic activity of the material, and further improve the efficiency of catalytic degradation of VOCs. If the material is not pickled directly and is baked, the thermal efficiency and organic matter removal effect of the material will decrease significantly.

[0061] The biomass baking treatment in step 2) can remove water and volatile organic compounds in the biomass, increase the carbon content and pore structure of the material, and after mixing and pyrolyzing with the porous aluminum refining waste residue, the carbonized product of the biomass can fill the pores of the waste residue to form a carbon-aluminum composite material, and the synergistic effect of the two steps can increase the carbon content, pore structure and thermal stability of the material, improve the adsorption and catalytic activity of the material, and further improve the efficiency of catalytic degradation of VOCs.

[0062] The CO2 coupling H2O activation in step 3) can increase the surface area and pore volume of the material, improve the activity of the material, and the impregnation method for loading active components (such as Ni and Fe) can increase the catalytic activity of the material. The synergistic effect of the two steps can increase the activity of the material and greatly improve the efficiency of catalytic degradation of VOCs.

[0063] Therefore, omitting any one step will result in a decrease in the activity of the material, and thus a decrease in thermal efficiency and removal rate. The synergy between the steps is the key to improving the performance of the material, and the absence of any one step will destroy this synergy.

[0064] Example 2

[0065] This example is to explore the influence of different mass ratios of porous aluminum refining waste and poplar sawdust mixed to prepare lotus-shaped carbon-aluminum composite hierarchical porous materials on thermal efficiency and removal rate. Specifically, the poplar sawdust after 260°C roasting treatment in step 2) of Example 1 is mixed with porous aluminum refining waste at a ratio of 1:1, 1:2, 1:4 and 2:1 respectively, and the degradation performance of different materials is determined. The results are shown in Table 2.

[0066] Table 2

[0067]

[0068] As can be seen from Table 2, different proportions of aluminum refining waste and poplar sawdust have a significant impact on the performance of the material. This is because during the mixed pyrolysis process, biomass and porous aluminum refining waste interact to form carbon-aluminum composite materials. This composite material has a hierarchical porous structure, with the carbon part having a large specific surface area and abundant pore structure, good adsorption capacity and catalytic activity for VOCs, and the aluminum part having good thermal conductivity and heat storage function to improve thermal efficiency.

[0069] However, the material with too high thermal efficiency, i.e. the mixture of biomass and porous aluminum refining waste at a ratio of 1:4, has a relatively high content of aluminum oxide in the waste, which has good heat storage function, thus improving the thermal efficiency. However, the carbonization product of biomass fills the pores of the waste, reducing the specific surface area and pore volume of the composite material, and thus reducing the adsorption and catalytic activity, thereby affecting the removal rate.

[0070] In summary, the mixture of poplar sawdust and aluminum refining waste plays an important role in adsorption, catalysis and heat conduction. The interaction between the two can improve the adsorption capacity, catalytic activity and thermal efficiency of the composite material, thereby improving the efficiency of removing organic pollutants. In the process of mixed pyrolysis, reasonable adjustment of the ratio of poplar sawdust and aluminum refining waste can further optimize the interaction and achieve efficient removal of VOCs.

[0071] Example 3

[0072] This example is to explore the influence of different active component loadings of lotus-shaped carbon-aluminum composite hierarchical porous materials on thermal efficiency and removal rate. Specifically, the mass fraction of Fe in step 3) of Example 1 is adjusted to 1%, 3%, 4% and 6%, and the degradation performance of different materials is determined. The results are shown in Table 3.

[0073] Table 3

[0074]

[0075] As can be seen from Table 3, the comprehensive performance is best when the loading amount of Fe is 4%, because the loaded active components Ni and Fe play a key role in catalytic degradation of VOCs, and in the activated composite hierarchical porous material, Ni and Fe can provide active sites to promote the degradation reaction of VOCs. By adjusting the content of Fe, the number and distribution of active sites can be affected, thereby affecting the efficiency of catalytic degradation. When the content of Fe is 4%, the number and distribution of active sites reach the best state.

[0076] In summary, the application discloses a method for disposing volatile organic pollutants by using aluminum smelting waste residue, and belongs to the field of inorganic and organic solid waste co-disposal. In view of the problems of high activity of aluminum smelting waste residue, excessive heavy metals, large pollution characteristics of volatile organic pollutants, low heat value, and difficulty in single technology processing, the catalytic characteristic components Fe, K, Ca, Mg, etc. in the aluminum smelting waste residue and the heat storage function of aluminum oxide are effectively utilized to catalyze and couple heat storage combustion of volatile organic pollutants, so that the volatile organic pollutants are harmlessly converted.

[0077] Firstly, the application utilizes co-pyrolysis of biomass and aluminum smelting waste residue to harmlessly dispose of the aluminum smelting waste residue and form carbon-aluminum composite porous material, thereby improving the heat conversion contact area and providing high-calorific-value biochar for combustion. Secondly, the carbon-aluminum composite material is physically activated and expanded, and effective active components are loaded. Finally, the carbon-aluminum composite porous material is formed into a lotus-shaped shape, thereby providing an effective diffusion surface for volatile organic pollutants.

[0078] Further, the application utilizes industrial waste as the main material to prepare carbon-aluminum composite porous catalytic material, which is applied to catalytic cracking, heat storage combustion and harmless disposal of volatile organic pollutants. Inorganic and organic pollutants can be harmlessly treated and high-valued, efficient clean conversion of pollution reduction and carbon reduction is achieved, energy and material are highly utilized, and the problem of waste pollution is solved. The thermal efficiency of the method is more than 90%, and the removal rate of volatile organic pollutants is greater than 99%.

[0079] It should be noted that the above examples are only used to illustrate the technical solutions of the application and are not limiting. Although the application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the application, which should be covered in the scope of the claims of the application.

Claims

1. The use of a lotus-shaped carbon-aluminum composite hierarchical porous particle material based on aluminum smelting waste residue in catalytic degradation of volatile organic pollutants, characterized in that: The preparation method of the lotus-shaped carbon-aluminum composite hierarchical porous particle material comprises the following steps: ​ The aluminum refining waste residue is baked and activated at 500-700 DEG C after acid washing, and a porous aluminum refining waste residue is obtained. The acid washing is carried out by using 0-8 mol / L organic acid at 50-150 DEG C for 30 min, and the acid concentration is not 0 during the acid washing, wherein the organic acid comprises one of acetic acid, phenol and benzoic acid. The biomass is mixed with the porous aluminum refining waste residue after baking treatment, and pyrolysis is carried out, so that a carbon-aluminum composite material is obtained. The treatment temperature of the biomass baking treatment is 220-300 DEG C, and the treatment time is 20-60 min, wherein the biomass is poplar sawdust, the pyrolysis temperature is 600-800 DEG C, and the pyrolysis time is 30-60 min. The carbon-aluminum composite material is activated by using CO2 coupling H2O, and then active components Ni and Fe are loaded by using the impregnation method, so that an activated composite hierarchical porous material is obtained. The carbon-aluminum composite material is activated by using CO2 coupling H2O, wherein the activation temperature is 800-1100 DEG C, the CO2 flow rate is 50-100 mL / min, the H2O flow rate is 0.5-2 g / min, the mass fraction of the active component Ni is 6-10%, and the mass fraction of Fe is 1-4%. The composite hierarchical porous material is pressure-formed in a lotus-shaped mold, so that a lotus-shaped carbon-aluminum composite hierarchical porous particle material is obtained.

2. Use according to claim 1, characterized in that: The method of the application comprises heating the lotus-shaped carbon-aluminum composite hierarchical porous material to 900 DEG C, and then introducing oxygen and volatile organic pollutants, so that catalytic degradation is realized, wherein the oxygen flow rate is 150 mL / min.

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