Carbon dioxide adsorbent material for electronic waste recycling and method for preparing the same

Abstract

A carbon dioxide adsorbent material derived from recycled electronic waste and its preparation method are disclosed. The carbon dioxide adsorbent material is prepared using non-metallic powder from electronic waste as raw material. On the one hand, the electronic waste is pretreated to ensure its high-value utilization; on the other hand, the high-performance adsorbent converted from it is directly used to capture carbon dioxide from industrial waste gas, thus treating another environmental pollutant at its source with one type of waste. This not only solves the difficulties in treating the non-metallic components of electronic waste and the resulting heavy pollution, but also provides a low-cost material for carbon dioxide emission reduction, while reducing the production cost of the adsorbent. It achieves a balance between environmental and economic benefits and is a typical practice of the circular economy concept.

Description

Technical Field

[0001] This invention belongs to the field of solid waste resource utilization and environmental protection functional materials technology, specifically relating to a carbon dioxide adsorption material for electronic waste recycling and its preparation method. Background Technology

[0002] With the rapid development of information technology and the accelerating pace of electronic and electrical product upgrades, the amount of global e-waste continues to surge. E-waste is complex in composition, encompassing various materials such as metals, plastics, ceramics, and fiberglass. Currently, relevant recycling technologies primarily focus on the extraction of precious metals such as gold, silver, copper, and palladium, as well as other valuable metals, with a strong economic focus. However, the non-metallic portion, which accounts for approximately 30%–40% of the total weight of e-waste (mainly non-metallic powder obtained after crushing and sorting, rich in resins, plastics, flame retardants, and fiberglass), has long faced the severe challenges of low recycling rates and high processing difficulty.

[0003] These non-metallic powders are often considered low- or worthless residues, and are currently mainly disposed of through landfill and incineration. Landfilling not only consumes a large amount of land resources, but the harmful substances it contains, such as brominated flame retardants, can also pollute the soil and groundwater through leachate. While incineration can reduce volume and recover some energy, it easily produces highly toxic gases such as dioxins and furans, as well as fly ash rich in heavy metals, causing serious secondary pollution. Therefore, developing environmentally friendly, high-value-added non-metallic powder resource utilization technologies has become a key link in promoting the clean utilization of all components of electronic waste and realizing a circular economy.

[0004] Using non-metallic powders from electronic waste—characterized by complex compositions, high impurity content, and challenging pretreatment—as raw materials to synthesize carbon dioxide adsorption materials remains a technological gap. The core challenges lie in overcoming the influence of impurity elements on the orderliness of the mesoporous structure and ensuring that the final synthesized material possesses carbon dioxide adsorption performance comparable to commercial products. Summary of the Invention

[0005] This invention provides a carbon dioxide adsorbent material recycled from electronic waste and its preparation method. The carbon dioxide adsorbent material is prepared using non-metallic powder from electronic waste as raw material. The core objective is to achieve a synergistic treatment effect of "treating waste with waste": on the one hand, it transforms the solid waste problem of electronic waste into a resource, realizing its high-value utilization; on the other hand, the high-performance adsorbent converted from it is directly used to capture carbon dioxide (another type of "waste," i.e., greenhouse gas) in industrial waste gas, thus using one type of waste to treat another environmental pollutant at its source. This not only solves the dilemma of difficult and heavily polluting non-metallic components of electronic waste, but also provides a low-cost material for carbon dioxide emission reduction, while reducing the production cost of the adsorbent, achieving a unity of environmental and economic benefits. It is a typical practice of the circular economy concept.

[0006] From a materials chemistry perspective, non-metallic powders from electronic waste are rich in elements such as silicon, carbon, and aluminum, especially the glass fibers and some ceramic components, which can serve as potential mineral raw materials for the preparation of silicon-aluminum based functional materials. This invention transforms these materials into mesoporous molecular sieves with regular pore structures and high specific surface areas, not only turning waste into treasure but also providing low-cost materials for adsorption, catalysis, and other fields.

[0007] This invention provides a method for preparing carbon dioxide adsorbent material from recycled electronic waste, comprising the following steps:

[0008] S1 obtains non-metallic powder from waste electronic and electrical products after crushing and sorting, and grinds and mixes the non-metallic powder with sodium hydroxide to obtain mixed powder;

[0009] The non-metallic powder comprises resin, plastic, flame retardant and glass fiber;

[0010] The mixed powder was pyrolyzed at 750℃~850℃ to obtain the pyrolysis product.

[0011] S2 pulverizes the pyrolysis product and mixes it with water, heats and dissolves it at 65℃~75℃ and filters it to remove solid impurities, obtaining solution A;

[0012] S3 mixes solution A with hydrochloric acid solution of poloxamer 188, stirs at 35℃~45℃ for more than 15 hours, heats up to 100℃ and holds until a precipitate is formed.

[0013] The ratio of solution A to the hydrochloric acid solution of poloxamer 188 is calculated as follows: 1.5 g to 2.5 g of poloxamer 188 per gram of pyrolysis product.

[0014] S4 After washing and drying the precipitate, it is heated to 500℃~600℃ in air at a rate of 4℃~6℃ / min and then held at the temperature to obtain the sintered product.

[0015] S5 mixes and reacts anhydrous ethanol solution of polyethyleneimine with the sintered product at 65℃~75℃, then washes and dries the mixture to obtain a carbon dioxide adsorbent material.

[0016] Preferably, in S1, the mass ratio of the non-metallic powder to sodium hydroxide is in the range of 1:0.3 to 1:1;

[0017] The equipment for the pyrolysis treatment is a tubular furnace, the pyrolysis temperature is 750℃~850℃, the pyrolysis temperature is reached by uniform heating, the uniform heating time is 130min~190min, the holding time is 0min, and the nitrogen flow rate is 150ml / min~250ml / min.

[0018] Preferably, in step S2, the pyrolysis product is pulverized and then mixed with water at a mass ratio of 1:1.5 to 1:2.5.

[0019] Preferably, in S3, the method for preparing the hydrochloric acid solution of poloxamer 188 includes: mixing and dissolving poloxamer 188 with hydrochloric acid at a ratio of 15 ml to 25 ml of 6 mol / L hydrochloric acid per gram of poloxamer 188.

[0020] Preferably, in step S4, the washing reagent is deionized water, the drying temperature is 60°C, and the drying time is 12 hours. The heat preservation time is 6 hours.

[0021] Preferably, in S5, the ratio of the anhydrous ethanol solution of polyethyleneimine to the sintered product is measured as follows: the mass ratio of polyethyleneimine to the sintered product is 1:1 to 1:2.5.

[0022] In step S5, the washing process specifically includes: vacuum filtration followed by washing and filtration with ethanol, repeated twice. The purpose of washing is to purify the modified product, clear pores, improve adsorption capacity and rate, stabilize the active components, prevent loss during use, and extend the material's lifespan. Ethanol has a much lower surface tension than water. During washing and drying, the lower surface tension reduces the "capillary pressure" damage to the activated carbon's pore structure, helping to maintain its porous structure.

[0023] This invention also provides a carbon dioxide adsorbent material for recycling electronic waste prepared by the aforementioned method, wherein the pore volume of the carbon dioxide adsorbent material is 0.518~0.697 cm³. 3 / g, with a specific surface area of ​​352.83~438.78m².2 / g, with an average pore radius of 58.78~61.73Å.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] This invention proposes and realizes the production of carbon dioxide adsorption materials using non-metallic powder from electronic waste as the main raw material. This achieves the resource utilization of waste, resulting in significant economic advantages.

[0026] This invention develops a proprietary pretreatment process including thermal decarbonization, acid washing for impurity removal, and activity regulation, which effectively removes organic impurities and suppresses interference from metal ions. By precisely controlling the synthesis system, the influence of impurities is successfully overcome, and a carbon dioxide adsorption material with a highly ordered structure, large specific surface area, and concentrated pore size distribution is prepared, achieving a qualitative leap from "complex waste" to "high-end material".

[0027] The present invention obtains an adsorbent material with good adsorption selectivity for carbon dioxide through amino modification. The amino functional group can react chemically with carbon dioxide molecules to form chemical bonds such as carbamate, which makes the amino-modified activated carbon highly selective for carbon dioxide and can preferentially adsorb carbon dioxide in a mixed gas.

[0028] The carbon dioxide adsorption material prepared by this invention has excellent key physicochemical parameters (specific surface area, pore volume) and carbon dioxide adsorption performance. It can be directly used as a high-efficiency adsorbent or high-quality carrier in serious scenarios such as industrial flue gas carbon capture, providing a stable and high-end outlet for electronic waste disposal with a clear and reliable value-added path.

[0029] This invention creatively combines three strategic needs—electronic waste resource utilization, low-cost manufacturing of new materials, and carbon dioxide emission reduction—into a single technical solution. It has comprehensive social value far exceeding that of a single technological improvement, is easy to obtain policy support, and has broad prospects for market application. Attached Figure Description

[0030] Figure 1 This is a flowchart illustrating the preparation process of the adsorbent materials obtained in Comparative Example 1 and Example 1.

[0031] Figure 2 The image shows the XRD characterization of the adsorbent material prepared in Example 1.

[0032] Figure 3 The image shows the FTIR characterization of the adsorbent material prepared in Example 1.

[0033] Figure 4 The carbon dioxide adsorption curve of the adsorbent material prepared in Example 1 is shown.

[0034] Figure 5The images show the non-metallic powder used in Example 1, the prepared adsorbent material, and the amine-modified adsorbent material. Detailed Implementation

[0035] To gain a deeper understanding of this invention, we will provide a comprehensive and detailed description.

[0036] Comparative Example 1

[0037] A carbon dioxide adsorption material using activated carbon as a carrier and its preparation method, comprising the following steps:

[0038] 0.9 g of tetraethylenepentamine (TEPA) was dissolved in 12 g of ethanol and stirred for 30 min using a magnetic stirrer. Then, 2.1 g of rice husk-based activated carbon was added and stirring continued for 3 h. After stirring, the sample was vacuum filtered, washed with ethanol, and the process was repeated twice. After treatment, the sample was dried in an oven at 80 °C, and after the alcohol had completely evaporated, it was completely dried at 100 °C for 1 h. Amino-modified rice husk-based activated carbon was obtained, denoted as TEPA-rice husk-30.

[0039] Carbon dioxide adsorption experiments were conducted using a surface area and pore size analyzer. The sample was first degassed in a vacuum environment at 120℃ for 6 hours, then placed in the surface area and pore size analyzer, and CO2 gas was introduced. The CO2 pressure was changed at 25℃ to obtain the CO2 adsorption curve.

[0040] Example 1

[0041] like Figure 1 A carbon dioxide adsorbent material recycled from electronic waste and its preparation method, comprising the following steps:

[0042] A certain amount of non-metallic powder was ground and mixed evenly with sodium hydroxide, with a mass ratio of non-metallic powder to sodium hydroxide of 1:0.5. The mixed powder was placed in a tube furnace for pyrolysis treatment at a temperature of 800℃, a heating rate of 5℃ / min, a holding time of 0min, and a nitrogen flow rate of 200ml / min. The pyrolysis product was ground into powder and subjected to thermal dissolution treatment. 15g of powder was taken and added to 30ml of deionized water, and dissolved by stirring in a water bath at 70℃ for 3h. The solution was then filtered to obtain solution A.

[0043] 2g of poloxamer 188 was dissolved in 40ml of HCl (6mol / L) and stirred in a 40℃ water bath for 3h. Solution A was then added, and stirring continued for 21h. After stirring, the solution was poured into a hydrothermal reactor for hydrothermal treatment at 100℃ for 24h. After hydrothermal treatment, the solution was filtered and washed three times with deionized water. The filtered product was dried in an oven at 60℃ for 12h. The dried product was calcined in a muffle furnace at 550℃, with a heating rate of 5℃ / min, for 6h to obtain a sintered product. 0.4g of polyethyleneimine was dissolved in a certain amount of anhydrous ethanol, and 0.6g of the sintered product was added. The mixture was stirred in a water bath at 70℃ for 12h. After the water bath, the product was centrifuged and washed three times with anhydrous ethanol. The filtered product was then dried in an oven at 60℃ for 12h. Carbon dioxide adsorbent material P-NMFs was obtained.

[0044] Carbon dioxide adsorption experiments were conducted using a surface area and pore size analyzer. The sample was first degassed in a vacuum environment at 120℃ for 6 hours, then placed in the analyzer, and CO2 gas was introduced. The CO2 pressure was varied at 25℃ to obtain the CO2 adsorption curve, as shown below. Figure 4 The physical images of the non-metallic powder used in Example 1, the prepared adsorbent material, and the amine-modified adsorbent material are shown in the following figures, in order: Figure 5 The three sub-figures are shown from bottom to top.

[0045] Specific surface area and pore size were analyzed for the amino-modified adsorbent materials of Comparative Example 1 and Example 1 to characterize the BET specific surface area, average pore size, and pore volume of different samples. Furthermore, the changes in the physical structure of P-NMFs prepared using non-metallic powder as the silicon source were analyzed, and the results are shown in Table 1. When the mass concentration of the modifier was the same, the specific surface area and pore volume of P-NMFs were larger. This is because the solution of the non-metallic powder after treatment is a highly soluble silicon source precursor with uniform reactivity. In hydrothermal synthesis, it can uniformly and synchronously self-assemble with poloxamer 188 to form a highly ordered Si-O-Si network and regular channels. PEI exhibits good flow and dispersion within the channels, with no obvious agglomeration and high pore structure integrity. The silanol groups (-SiOH) on the surface of the pure SiO2 framework are uniform, and PEI is bonded to the silanol groups by hydrogen bonds / covalent bonds. After loading, the uniformity of the pore size is maintained, and there is no trend of pore size increase. Rice husks are composed of cellulose, hemicellulose, lignin, and a large amount of SiO2, which form an amorphous carbon skeleton after activation. The pores of rice husk activated carbon are twisted and poorly connected, and TEPA tends to agglomerate at the pore openings or inflection points, forming pore bottlenecks and further reducing the effective specific surface area and pore volume. Agglomeration also squeezes adjacent pores, causing small pores to merge into large pores and increasing the average pore diameter.

[0046] Table 1: Specific surface area, average pore diameter, and pore volume of the products of Comparative Example 1 and Example 1.

[0047]

[0048] XRD analysis was performed on Example 1 to characterize the physical structure of P-NMFs, and the results are as follows: Figure 2 As shown, the blue curve after background subtraction exhibits a series of clear diffraction peaks in the low 2θ region (~1–4°), indicating that the material possesses long-range ordered channels and a layered structure, providing uniform adsorption sites and diffusion channels—one of the core characteristics of highly efficient CO2 adsorption materials. The labeled d values ​​range from 10.51 Å to 2.03 Å, corresponding to channels and interlayer spacings in the range of 1–10 nm, belonging to the mesoporous scale (2–50 nm). These channels ensure rapid diffusion of CO2 molecules and can enhance adsorption selectivity through surface modification. The signal flattens out after θ>5°, with no obvious strong peaks, indicating that the material lacks additional ordered structures at larger scales; the main structural information is concentrated at the mesoporous scale, consistent with the typical characteristics of porous materials for CO2 adsorption.

[0049] FTIR analysis was performed on the amino-modified adsorbent material of Example 1 to characterize the functional structure of P-NMFs, etc. The results are as follows: Figure 3 As shown. The three characteristic peak positions are (~3439, ~2929, ~1657 cm⁻¹). -1 All these findings clearly point to the presence of PEI organic functional groups and their interaction with the adsorbent support, strongly demonstrating that PEI has been successfully loaded onto the adsorbent material. ~3439cm -1 The peak is a broad and strong absorption peak, one of the most significant characteristics of the modified material. It is a superposition of the following two factors: the stretching vibrations of silanol groups (Si-OH) on the surface of the adsorbent material and the OH stretching vibrations of physically adsorbed water (~3400 cm⁻¹). -1 The NH stretching vibration of amine groups (-NH2, -NH-) in PEI (~3300-3500 cm⁻¹) -1 The significant broadening of the peak indicates that a strong hydrogen bond has formed between the amine groups of PEI and the silanol groups on the surface of the adsorbent material. This is a typical characteristic of organic-inorganic composite materials, proving that PEI is not a simple physical mixture, but rather interacts closely with the support. ~2929cm -1 The peak is attributed to the CH stretching vibration of the methylene (-CH2-) group in the PEI molecular chain. The appearance of this peak is the most direct and conclusive evidence of the successful introduction of this organic amine polymer into PEI. ~1657cm -1 The peak is mainly attributed to two possibilities: the NH bending vibration of the primary amine (-NH2) in PEI (typically at 1600-1640 cm⁻¹). -1The HOH bending vibration of adsorbed water molecules (typically at 1630 cm⁻¹). -1 (Approximately). In PEI-modified materials, the two often overlap. The presence of this peak further supports the existence of amine or water-related interactions.

[0050] Carbon dioxide adsorption experiments were conducted on the amino-modified adsorbents of Comparative Example 1 and Example 1 to analyze their carbon dioxide adsorption performance. At 25°C and with an amino loading of 30%, the ammonia-modified adsorbent TEPA-rice husk-30, prepared from activated carbon, exhibited a CO2 adsorption capacity of 20.16 cm⁻¹. 3 / g, the CO2 adsorption capacity of P-NMFs, an ammonia-modified adsorbent material prepared from non-metallic powder, is 19.76394 cm⁻¹. 3 / g, the carbon dioxide adsorption capacity of both is comparable, but the adsorption capacity of P-NMFs is slightly worse. This is because although the non-metallic powder is pretreated, it still contains trace impurities (such as metal ions and organic residues), which slightly affect the condensation of silicon species and the orderliness of the channels, while changing the density of silanol groups or acid sites on the surface of the molecular sieve, thus slightly affecting the anchoring stability of PEI or the effective utilization rate of amine groups.

[0051] In summary, this invention uses non-metallic powder as a silicon source to prepare an adsorbent carrier. The resulting adsorbent material, loaded with polyethyleneimine, exhibits comparable performance to commercial adsorbent materials in key physicochemical parameters (specific surface area, pore volume) and carbon dioxide adsorption capacity. This not only completely avoids the environmental hazards of traditional treatment methods, but also allows the final product, P-NMFs, to be directly used for carbon dioxide capture, contributing to greenhouse gas emission reduction. From process to end-use, it achieves the dual environmental benefits of "treating pollution with waste."

[0052] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a carbon dioxide adsorbent material for electronic waste recycling, characterized by, Includes the following steps: S1 obtains non-metallic powder from waste electronic and electrical products after crushing and sorting, and grinds and mixes the non-metallic powder with sodium hydroxide to obtain mixed powder; The non-metallic powder comprises resin, plastic, flame retardant and glass fiber; The mixed powder was pyrolyzed at 750℃~850℃ to obtain the pyrolysis product. S2 pulverizes the pyrolysis product and mixes it with water, heats and dissolves it at 65℃~75℃ and filters it to remove solid impurities, obtaining solution A; S3 mixes solution A with hydrochloric acid solution of poloxamer 188, stirs at 35℃~45℃ for more than 15 hours, heats up to 100℃ and holds until a precipitate is formed. The ratio of solution A to the hydrochloric acid solution of poloxamer 188 is calculated as follows: 1.5 g to 2.5 g of poloxamer 188 per gram of pyrolysis product. S4 After washing and drying the precipitate, it is heated to 500℃~600℃ in air at a rate of 4℃~6℃ / min and then kept at the temperature to obtain the sintered product. S5 mixes and reacts anhydrous ethanol solution of polyethyleneimine with the sintered product at 65℃~75℃, then washes and dries the mixture to obtain a carbon dioxide adsorbent material.

2. The preparation method according to claim 1, characterized in that, In S1, the mass ratio of the non-metallic powder to sodium hydroxide ranges from 1:0.3 to 1:

1.

3. The preparation method according to claim 1, characterized in that, In S1, the equipment for pyrolysis is a tubular furnace, the pyrolysis temperature is 750℃~850℃, the pyrolysis temperature is reached by uniform heating, the uniform heating time is 130min~190min, the holding time is 0min, and the nitrogen flow rate is 150ml / min~250ml / min.

4. The preparation method according to claim 1, characterized in that, In step S2, the pyrolysis product is pulverized and mixed with water at a mass ratio of 1:1.5 to 1:2.

5.

5. The preparation method according to claim 1, characterized in that, In S3, the method for preparing the hydrochloric acid solution of poloxamer 188 includes: mixing and dissolving poloxamer 188 with hydrochloric acid at a ratio of 15 ml to 25 ml of 6 mol / L hydrochloric acid per gram of poloxamer 188.

6. The preparation method according to claim 1, characterized in that, In S4, the drying process is carried out at a temperature of 60°C for 12 hours.

7. The preparation method according to claim 1, characterized in that, In S4, the heat preservation time for the heat preservation treatment is 6 hours.

8. The preparation method according to claim 1, characterized in that, In S4, the reagent used for the washing process is deionized water.

9. The preparation method according to claim 1, characterized in that, In S5, the ratio of the anhydrous ethanol solution of polyethyleneimine to the sintered product is measured as follows: the mass ratio of polyethyleneimine to sintered product is 1:1 to 1:2.

5. The washing process specifically includes: first, vacuum filtration, then washing and filtration with ethanol, and repeating the vacuum filtration and ethanol washing and filtration process several times.

10. The carbon dioxide adsorbent material for electronic waste regeneration prepared by the preparation method according to any one of claims 1 to 9, characterized in that, The pore volume of the carbon dioxide adsorption material is 0.518~0.697cm 3 / g, the specific surface area is 352.83~438.78m 2 / g, and the average pore radius is 58.78~61.73Å.

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