Method for preparing catalyst by taking retired ternary power battery as raw material and application of catalyst

Abstract

The invention relates to the technical field of solid waste resource utilization, in particular to a method for preparing a catalyst by taking a retired ternary power battery as a raw material and application of the catalyst, and particularly relates to a method for preparing a catalyst by taking a retired ternary power battery as a raw material and application of the catalyst. The method is mainly characterized in that metal elements such as lithium, nickel, cobalt and manganese in the ternary power battery are recycled through carbon thermal reduction of waste biomass in a mixed atmosphere of N2 and CO2. In the preparation process, the lithium element reacts with CO2 in a mixed atmosphere to generate water-soluble Li2CO3, the biomass can form porous biochar in the mixed atmosphere, and nickel cobalt manganese oxide residues after water immersion and the biochar remaining after carbon thermal reduction are mechanically ball-milled to prepare the NiCoMnOx / biochar catalyst. The method is simple in process and low in cost, shows a good effect on catalytic oxidation degradation of VOCs, and achieves the purpose of treating waste with waste.

Description

Technical Field

[0001] The present invention relates to the technical field of solid waste resource utilization, and in particular to a method for preparing a catalyst using retired ternary power batteries as raw materials and an application thereof. Background Art

[0002] With the rapid development of industries such as petrochemicals, spraying, shoemaking and printing, the emission of volatile organic compounds (VOCs), represented by aromatic organic compounds, has gradually increased, posing a threat to the environment, plant and animal growth and human health. Catalytic oxidation has become a research hotspot in the current organic waste gas treatment industry due to its high purification rate, no secondary pollution and low energy consumption, and the preparation of cheap and efficient catalysts is the core of catalytic oxidation technology.

[0003] Nowadays, the inadequate utilization of waste biomass has also led to a series of environmental problems. Therefore, it is of great significance to improve the resource utilization rate of waste biomass and convert it into high value-added materials through scientific methods.

[0004] In recent years, the rapid development of the electric vehicle industry has led to the large-scale generation of ternary power battery waste. Among all the components of discarded ternary power batteries, the positive electrode is the most valuable because it is rich in valuable metals such as cobalt, nickel and manganese. Ni, Co and Mn, as non-precious metal elements of groups VIIB and VIII, are very suitable as active substances for the preparation of low-cost heterogeneous catalysts.

[0005] Therefore, more and more people have conducted research on recycling nickel, cobalt and manganese elements from discarded ternary power batteries for the preparation of value-added catalytic materials. Liang et al. used discarded ternary lithium-ion batteries to synthesize magnetically separated MFO-LIB for the first time, which was used to activate peroxymonosulfate to degrade bisphenol A, showing excellent removal effect (Chemical Engineering Journal 2022, 435, 135000). Wu et al. used discarded ternary power batteries as precursors to prepare NiCoMnOx catalysts for NH 3 -SCR, the prepared catalyst presents a porous and fluffy foam structure, has rich oxygen defects, and also shows excellent catalytic effect at low temperatures (Chemical Engineering Journal 2024,481,148564). For the catalytic oxidation of VOCs, metals such as cobalt, nickel, and manganese are also often used to prepare catalysts. Recycling nickel, cobalt, and manganese in discarded lithium batteries for the active components of the catalyst can not only solve the above problems, but also control air pollution. Therefore, it is of great significance to develop a method for preparing a catalyst using discarded lithium batteries and waste biomass as raw materials and use it for catalytic oxidation and degradation of VOCs. Summary of the invention

[0006] Considering that the recycling of valuable metals in the positive electrode powder of discarded lithium batteries and the full utilization of discarded biomass can reduce the waste of resources, and the large-scale emission of VOCs gas in recent years has caused serious environmental problems. The present invention provides a method for preparing a catalyst using discarded lithium batteries and discarded biomass as raw materials and its application. The preparation method is simple in process and low in cost. The prepared catalyst is used for catalytic oxidation degradation of VOCs, which can achieve the effect of treating waste with waste.

[0007] The technical solution adopted by the present invention to solve the technical problem is: a method for preparing a catalyst using retired ternary power batteries as raw materials, comprising the following steps:

[0008] S1. Discharging, disassembling, screening and other pre-treatments are performed on retired ternary power batteries to obtain battery positive electrode powder. After ICP element testing, its main components are Li (5%), Ni (21%), Co (8.5%), and Mn (11.5%);

[0009] S2, the ternary battery positive electrode powder obtained in step S1 and the waste biomass are uniformly mixed and added to the porcelain boat, 2 and CO 2 Calcination in a tubular furnace under an atmosphere with a flow rate of 1:1-1:5;

[0010] S3, taking out the solid calcined in step S2, adding distilled water for water soaking, repeating 3 times, and then filtering to obtain the water soaked solid;

[0011] S4. Dry the solid after water immersion in step S3 and add it into a ball mill reactor at a rotation speed of 600 r / min for a ball milling time of 60-240 min.

[0012] Furthermore, in step S2, the calcination temperature of the tubular furnace is 500-800°C, and the mass ratio of waste lithium batteries to waste biomass is 1:1-1:4.

[0013] Furthermore, in step S2, the waste biomass is one or more of walnut shells, pomegranate peels, and straw.

[0014] Furthermore, in step S3, the immersion time is 10-60 min / time.

[0015] Further, in step S2, the positive electrode powder of the ternary power battery and the waste biomass pomegranate peel are uniformly mixed in a mass ratio of 1:4 and added into the porcelain boat. 2 and CO 2 The calcination was carried out in a tubular furnace under an atmosphere with a flow rate of 1:5 and a calcination temperature of 500°C.

[0016] Further, in step S2: the positive electrode powder of the ternary power battery and the waste biomass straw are uniformly mixed in a mass ratio of 1:2 and added into the porcelain boat. 2 and CO 2 The calcination was carried out in a tubular furnace under an atmosphere with a flow rate of 1:1 and a calcination temperature of 800°C.

[0017] Further, in step S2, the positive electrode powder of the ternary power battery and the waste biomass walnut shells are uniformly mixed in a mass ratio of 1:1 and added to the porcelain boat. 2 and CO 2 The calcination was carried out in a tubular furnace under an atmosphere with a flow rate of 1:2 and a calcination temperature of 700°C.

[0018] Further, in step S2, the positive electrode powder of the ternary power battery and the waste biomass walnut shells are uniformly mixed in a mass ratio of 1:1 and added to the porcelain boat. 2 and CO 2 The calcination was carried out in a tubular furnace under an atmosphere with a flow rate of 1:2 and a calcination temperature of 700°C.

[0019] A method for using a catalyst for thermal catalytic degradation of VOC gas toluene, characterized in that the catalyst obtained in claim 1 is placed in a reactor, and N 2 Toluene is bubbled and air is introduced into the reaction device as a balance gas. The temperature of the reaction furnace is then increased to perform catalytic oxidation degradation of toluene.

[0020] Furthermore, the initial concentration of the test was 1500 ppm, after which the reactor was heated up, and the real-time concentration was recorded every 10°C to calculate the degradation rate of toluene.

[0021] The beneficial effects of the present invention are:

[0022] 1. Using carbon thermal reduction of waste biomass to recycle waste lithium batteries is highly efficient and avoids the use of large amounts of acid and alkali, which has higher economic benefits.

[0023] 2. In N 2 and CO 2 In the atmosphere of decommissioning, the Li element in the ternary power battery will react with CO 2 The reaction forms Li2CO3, achieving high-value recovery of Li elements. 2 / CO 2 Calcination under atmosphere will also produce more pores, which is beneficial to the subsequent adsorption of VOCs.

[0024] 3. The catalyst can be directly formed after ball milling without going through a calcination process, which is simple and convenient.

[0025] 4. The present invention utilizes waste lithium batteries and waste biomass as raw materials to prepare catalysts for catalytic oxidation of VOCs, thereby avoiding a large amount of resource waste and treating harmful gases in the atmosphere, thus achieving the purpose of treating waste with waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0027] Figure 1 This is the XRD pattern of the NiCoMnOx / biochar catalyst in the present invention.

[0028] Figure 2 It is a scanning electron microscope image of the active component of the present invention showing the spinel structure.

[0029] Figure 3 It is a scanning electron microscope image of the active component of the present invention showing the spinel structure.

[0030] Figure 4 It is a schematic diagram showing the EPR characterization results in the present invention. DETAILED DESCRIPTION

[0031] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0032] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] The invention discloses a method for preparing a catalyst using retired ternary power batteries as raw materials and application thereof.

[0034] Reference Figure 1 and Figure 2 A method for preparing a catalyst using retired ternary power batteries as raw materials comprises the following steps:

[0035] S1. The retired ternary power batteries are discharged, disassembled, screened and other pre-processed to obtain battery positive electrode powder. After ICP element testing, its main components are Li (5%), Ni (21%), Co (8.5%) and Mn (11.5%).

[0036] S2, the ternary battery positive electrode powder obtained in step S1 and the waste biomass are uniformly mixed and added to the porcelain boat, 2 and CO 2 The calcination is carried out in a tubular furnace under an atmosphere with a flow rate of 1:1-1:5, the calcination temperature of the tubular furnace is 500-800°C, the mass ratio of waste lithium batteries to waste biomass is 1:1-1:4, and the waste biomass can be one or more of walnut shells, pomegranate peels, straw, etc.

[0037] S3. Take out the solid calcined in step S2, add distilled water for water soaking, repeat 3 times, and then filter to obtain the soaked solid, the soaking time is 10-60 min / time.

[0038] S4. Dry the solid after water immersion in step S3 and add it into a ball mill reactor at a rotation speed of 600 r / min for a ball milling time of 60-240 min.

[0039] Embodiment 1:

[0040] S1. Discharging, disassembling and other pre-treatments are performed on the discarded lithium batteries to obtain positive electrode powder for ternary power batteries.

[0041] S2. The positive electrode powder of the ternary power battery and the waste biomass walnut shells were uniformly mixed in a mass ratio of 1:3, added into a porcelain boat, and calcined in a tubular furnace under an atmosphere of N2 and CO2 flow rate of 1:2. The calcination temperature was 600°C.

[0042] S3. Add distilled water to the solid obtained after calcination, soak in water for 40 minutes, and repeat 3 times.

[0043] S4. Add the solid after water immersion, filtration and drying into a ball mill reactor at a rotation speed of 600 r / min and a reaction time of 180 min to obtain a finished NiCoMnOx / biocarbon catalyst.

[0044] The sample was subjected to an X-ray powder diffraction experiment, and the morphology and structure of the catalyst were observed under a scanning electron microscope. The XRD pattern of the NiCoMnOx / biochar catalyst prepared according to the process parameters of Example 1 was as follows: Figure 1 As shown, by comparing the PDF card (JCPDS#42 1467), it can be seen that Co appears at angles of 18.9°, 31.2°, 36.8°, 38.5°, etc. 3 O 4 Unique diffraction characteristic peaks. Considering that the ionic radii of Co, Ni, and Mn are close, it is possible that Ni and Mn doped Co 3 O 4 The characteristic peaks of NiOx and MnOx cannot be detected. Figure 2 and Figure 3 , which proves that the active components of the spinel structure are uniformly dispersed on the biochar. The NiCoMnOx / biochar catalyst prepared in Example 1 was tested by EPR characterization. Figure 4 The characterization results show that the NiCoMnOx / biochar catalyst prepared in Example 1 has more oxygen vacancies.

[0045] The present invention also provides an application method of the NiCoMnOx / biochar catalyst for thermal catalytic degradation of VOC gas toluene.

[0046] The method comprises: placing the NiCoMnOx / biochar catalyst obtained in Example 1 into a quartz tube of an evaluation device, bubbling toluene with N2, and simultaneously introducing air as a balance gas into the reaction device, testing the initial concentration (1500 ppm), then heating the reaction furnace, recording the real-time concentration every 10°C, and calculating the degradation rate of toluene. Generally, the temperature at which the degradation rate reaches 90% is used as the evaluation value of the ability to degrade toluene, i.e., T 90 .

[0047] The above method was used to test the T of NiCoMnOx / biochar catalyst in the degradation of toluene. 90 260℃

[0048] Embodiment 2:

[0049] S1. Pretreatment of waste lithium batteries is consistent with step S1 of Example 1.

[0050] S2, the ternary power battery positive electrode powder and the waste biomass pomegranate peel were mixed evenly in a mass ratio of 1:4 and added into the porcelain boat. 2 and CO 2 The calcination was carried out in a tubular furnace under an atmosphere with a flow rate of 1:5 and a calcination temperature of 500°C.

[0051] S3. Add distilled water to the solid obtained after calcination, soak in water for 10 minutes, and repeat 3 times.

[0052] S4. Add the solid after water immersion, filtration and drying into a ball mill reactor at a rotation speed of 600 r / min and a reaction time of 120 min to obtain a finished NiCoMnOx / biocarbon catalyst.

[0053] The T of NiCoMnOx / biochar catalyst in degrading toluene was tested by the method of Example 1. 90 is 275℃.

[0054] Embodiment 3:

[0055] S1. Pretreatment of waste lithium batteries is consistent with step S1 of Example 1.

[0056] S2, the ternary power battery positive electrode powder and waste biomass straw were mixed evenly in a mass ratio of 1:2 and added into the porcelain boat. 2 and CO 2 The calcination was carried out in a tubular furnace under an atmosphere with a flow rate of 1:1 and a calcination temperature of 800°C.

[0057] S3. Add distilled water to the solid obtained after calcination, soak in water for 60 minutes, and repeat 3 times.

[0058] S4. Add the solid after water immersion, filtration and drying into a ball mill reactor at a rotation speed of 600 r / min and a reaction time of 60 min to obtain a finished NiCoMnOx / biocarbon catalyst.

[0059] The T of NiCoMnOx / biochar catalyst in degrading toluene was tested by the method of Example 1. 90 It is 290℃.

[0060] Embodiment 4:

[0061] S1. Pretreatment of waste lithium batteries is consistent with step S1 of Example 1.

[0062] S2, the ternary power battery positive electrode powder and the waste biomass walnut shells were mixed uniformly in a mass ratio of 1:1 and added into the porcelain boat. 2 and CO 2 The calcination was carried out in a tubular furnace under an atmosphere with a flow rate of 1:2 and a calcination temperature of 700°C.

[0063] S3. Add distilled water to the solid obtained after calcination, soak in water for 50 minutes, and repeat 3 times.

[0064] S4. Add the solid after water immersion, filtration and drying into a ball mill reactor at a rotation speed of 600 r / min and a reaction time of 240 min to obtain a finished NiCoMnOx / biocarbon catalyst.

[0065] The T of NiCoMnOx / biochar catalyst in degrading toluene was tested by the method of Example 1. 90 is 280℃.

[0066] Embodiment 5:

[0067] S1. Pretreatment of waste lithium batteries is consistent with step S1 of Example 1.

[0068] S2, the ternary power battery positive electrode powder and waste biomass straw were mixed evenly in a mass ratio of 1:3 and added into the porcelain boat. 2 and CO 2 The calcination was carried out in a tubular furnace under an atmosphere with a flow rate of 1:3 and a calcination temperature of 800°C.

[0069] S2. Add distilled water to the solid obtained after calcination, soak in water for 10 minutes, and repeat 3 times.

[0070] S4. Add the solid after water immersion, filtration and drying into a ball mill reactor at a rotation speed of 600 r / min and a reaction time of 180 min to obtain a finished NiCoMnOx / biocarbon catalyst.

[0071] The T of NiCoMnOx / biochar catalyst in degrading toluene was tested by the method of Example 1. 90 It is 293℃.

[0072] Comparative Example 1:

[0073] S1. Discharging, disassembling and other pre-treatments are performed on the discarded lithium batteries to obtain positive electrode powder for ternary power batteries.

[0074] S2, add the positive electrode powder of the ternary power battery into the porcelain boat, 2 and CO 2 The calcination was carried out in a tubular furnace under an atmosphere with a flow rate of 1:2 and a calcination temperature of 600°C.

[0075] S3. Add distilled water to the solid obtained after calcination, soak in water for 40 minutes, and repeat 3 times.

[0076] S4. Add the solid after water immersion, filtration and drying into a ball mill reactor at a rotation speed of 600 r / min and a reaction time of 180 min to obtain the finished catalyst of Comparative Example 1.

[0077] The T of the catalyst in degrading toluene was tested by the method of Example 1. 90 380℃

[0078] Its poor catalytic activity is because no waste biomass is added during the calcination process, which results in the inability of the ternary power battery to undergo carbon thermal reduction reaction, and the nickel, cobalt and manganese elements in the battery cannot be effectively reduced.

[0079] Comparative Example 2:

[0080] S1. Discharging, disassembling and other pre-treatments are performed on the discarded lithium batteries to obtain positive electrode powder for ternary power batteries.

[0081] S2, the ternary power battery positive electrode powder and the waste biomass walnut shells were mixed evenly in a mass ratio of 1:3 and added into the porcelain boat. 2 The calcination temperature is 600℃ in a tubular furnace under atmosphere.

[0082] S3. Add distilled water to the solid obtained after calcination, soak in water for 40 minutes, and repeat 3 times.

[0083] S4. Add the solid after water immersion, filtration and drying into a ball mill reactor at a rotation speed of 600 r / min and a reaction time of 180 min to obtain the finished comparative example 2 catalyst.

[0084] The T of the catalyst in degrading toluene was tested by the method of Example 1. 90 is 300℃.

[0085] The poor catalytic effect is due to the fact that biomass 2 and CO 2 When calcined in a mixed atmosphere, the biochar formed will have more pores, which will be more conducive to the adsorption of VOCs. 2 Calcination under atmosphere cannot achieve the above-mentioned effects.

[0086] Comparative Example 3:

[0087] S1. Discharging, disassembling and other pre-treatments are performed on the discarded lithium batteries to obtain positive electrode powder for ternary power batteries.

[0088] S2, the positive electrode powder of the ternary power battery and the waste biomass walnut shells were mixed evenly in a mass ratio of 1:3 and added into the porcelain boat. 2 The calcination temperature is 600℃.

[0089] S3. Add distilled water to the solid obtained after calcination, soak in water for 40 minutes, and repeat 3 times.

[0090] S4. Add the solid after water immersion, filtration and drying into a ball mill reactor at a rotation speed of 600 r / min and a reaction time of 180 min to obtain the finished comparative example 3 catalyst.

[0091] The T of the catalyst in degrading toluene was tested by the method of Example 1. 90 It is 352℃.

[0092] The poor catalytic effect is due to the 2 Calcination under atmosphere will lead to a large amount of volatilization of biomass, affecting the amount of biochar generated. As a result, NiCoMnOx will be too agglomerated on the biochar in subsequent treatment, thus affecting the catalytic activity.

[0093] Comparative Example 4:

[0094] S1. Discharging, disassembling and other pre-treatments are performed on the discarded lithium batteries to obtain positive electrode powder for ternary power batteries.

[0095] S2, the ternary power battery positive electrode powder and the waste biomass walnut shells were mixed evenly in a mass ratio of 1:3 and added into the porcelain boat. 2 and CO 2 The calcination was carried out in a tubular furnace under an atmosphere with a flow rate of 1:2 and a calcination temperature of 600°C.

[0096] S3. Add distilled water to the solid obtained after calcination, soak in water for 40 minutes, and repeat 3 times.

[0097] After water soaking, filtering and drying, the finished product of the comparative example 4 catalyst was obtained.

[0098] The T of the catalyst in degrading toluene was tested by the method of Example 1. 90 It is 335℃.

[0099] The reason for its poor catalytic effect is that nickel-cobalt-manganese oxide cannot be loaded on biochar without ball milling treatment. The two are simply mixed and cannot interact with each other.

[0100] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A method for preparing a catalyst using retired ternary power batteries as raw materials, characterized in that: The steps include: S1. Discharging, disassembling, screening and other pre-treatments are performed on retired ternary power batteries to obtain battery positive electrode powder. After ICP element testing, its main components are Li (5%), Ni (21%), Co (8.5%), and Mn (11.5%); S2, uniformly mixing the ternary battery positive electrode powder obtained in step S1 and the waste biomass, adding the mixture into a porcelain boat, and calcining in a tubular furnace in an atmosphere where the flow rate of N2 and CO2 is 1:1-1:5; S3, taking out the solid calcined in step S2, adding distilled water for water soaking, repeating 3 times, and then filtering to obtain the water soaked solid; S4. Dry the solid after water immersion in step S3 and add it into a ball mill reactor at a rotation speed of 600 r / min for a ball milling time of 60-240 min.

2. The method for preparing a catalyst using retired ternary power batteries as raw materials according to claim 1, characterized in that: In step S2, the calcination temperature of the tubular furnace is 500-800°C, and the mass ratio of waste lithium batteries to waste biomass is 1:1-1:

4.

3. The method for preparing a catalyst using retired ternary power batteries as raw materials according to claim 2, characterized in that: In step S2, the waste biomass is one or more of walnut shells, pomegranate peels, and straw.

4. The method for preparing a catalyst using retired ternary power batteries as raw materials according to claim 3, characterized in that: In step S3, the immersion time is 10-60 min / time.

5. The method for preparing a catalyst using retired ternary power batteries as raw materials according to claim 3, characterized in that: In step S2, the positive electrode powder of the ternary power battery and the waste biomass pomegranate peel are uniformly mixed in a mass ratio of 1:4 and added to a porcelain boat, and calcined in a tubular furnace under an atmosphere of N2 and CO2 flow rate of 1:5, and the calcination temperature is 500°C.

6. The method for preparing a catalyst using retired ternary power batteries as raw materials according to claim 3, characterized in that: In step S2: the positive electrode powder of the ternary power battery and the waste biomass straw are uniformly mixed in a mass ratio of 1:2 and added into a porcelain boat, and calcined in a tubular furnace under an atmosphere of N2 and CO2 flow rate of 1:1, and the calcination temperature is 800°C.

7. The method for preparing a catalyst using retired ternary power batteries as raw materials according to claim 3, characterized in that: In step S2, the positive electrode powder of the ternary power battery and the waste biomass walnut shells are uniformly mixed in a mass ratio of 1:1 and added to a porcelain boat, and calcined in a tubular furnace under an atmosphere of N2 and CO2 flow rate of 1:2, and the calcination temperature is 700°C.

8. The method for preparing a catalyst using retired ternary power batteries as raw materials according to claim 3, characterized in that: In step S2, the positive electrode powder of the ternary power battery and the waste biomass walnut shells are uniformly mixed in a mass ratio of 1:1 and added to a porcelain boat, and calcined in a tubular furnace under an atmosphere of N2 and CO2 flow rate of 1:2, and the calcination temperature is 700°C.

9. A method for using a catalyst for thermal catalytic degradation of VOC gas toluene, characterized in that: The catalyst obtained in claim 1 is placed in a reactor, toluene is bubbled through N2, and air is used as a balance gas and simultaneously introduced into the reaction device, after which the reactor is heated to perform catalytic oxidation degradation of toluene.

10. The method for using the catalyst as claimed in claim 9 for thermal catalytic degradation of VOC gas toluene, characterized in that: The initial test concentration was 1500ppm. After that, the reactor was heated up, and the real-time concentration was recorded every 10°C to calculate the degradation rate of toluene.

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