Industrial solid waste-based carbon powder catalyst, and preparation method and application thereof

Abstract

The invention provides an industrial solid waste-based carbon powder catalyst as well as a preparation method and application thereof, and relates to the technical field of chemical recovery of waste plastics. The industrial solid waste-based carbon powder takes biochar as a substrate, and effective components comprise biomass components and element components such as silicon, aluminum, iron, calcium, magnesium and titanium. The waste plastic cracking method comprises the following steps: adding waste plastic and a catalyst into a batch reactor, and then carrying out waste plastic thermal cracking at a certain temperature to prepare oil. The plastic comprises polyethylene and polypropylene; the plastic oil is C5-C20 hydrocarbon substances and comprises alkane, olefin and aromatic hydrocarbon; the catalyst is an industrial solid waste-based carbon powder catalyst. Efficient conversion of waste plastics can be achieved, the prepared fuel oil is high in yield and heat value, and the problem of plastic garbage pollution can be effectively relieved; the adopted catalyst is low in cost and has good economic feasibility.

Description

Technical Field

[0001] This invention relates to the field of chemical recycling technology for waste plastics, and in particular to an industrial solid waste-based carbon powder catalyst, its preparation method, and its application. Background Technology

[0002] With the booming development of the petrochemical industry, plastic products have been widely used in food, medical, construction, and agriculture. Currently, the plastics industry can be divided into general-purpose plastics, represented by polyethylene and polypropylene; engineering plastics, represented by polyamide and polycarbonate; and specialty plastics, represented by polyetheretherketone and polyimide. Among these materials, polyethylene and polypropylene have the largest total production and usage.

[0003] Improper disposal of waste plastics can severely damage ecosystems. Currently, there are three main methods for handling waste plastics: landfill, incineration, and recycling. Landfill disposal, however, occupies large amounts of land resources for a long time because plastics are extremely difficult to degrade in the natural environment; incineration produces large amounts of greenhouse gases and releases pollutants such as dioxins and NOx. X SO X These methods, which involve the production and disposal of toxic and harmful gases, are gradually being phased out in line with the concept of green development. Meanwhile, resource recovery solutions, represented by pyrolysis technology, are showing broad application prospects.

[0004] One method discloses a solid acid catalyst for the depolymerization of waste plastics and its preparation method. This method involves loading active components onto surface-modified activated carbon to obtain a precursor, which is then calcined to obtain the solid acid catalyst. The precursor is prepared by soaking activated carbon in a mixed solution of NaOH and KOH to obtain alkali-modified activated carbon, and then loading nano-silica onto the alkali-modified activated carbon. This catalyst promotes the cracking process of polyolefins and increases the yield of liquid oil by increasing the reaction contact area of ​​the active components. Another method discloses a catalyst for the production of fuel oil from waste plastics and its preparation method. This method involves preparing modified pillared clay from montmorillonite or kaolinite groups, and then loading it with metallic active components to obtain the catalyst. This catalyst eliminates the need for pre-pyrolysis sorting of mixed plastic waste while maintaining high conversion rates and high liquid hydrocarbon yields.

[0005] Although the catalysts mentioned above are based on natural resources, they suffer from problems such as complex preparation processes, high raw material costs, and strong resource dependence, making it difficult to balance catalytic performance and economic feasibility, which restricts the large-scale promotion and application of chemical recycling technology for waste plastics. Summary of the Invention

[0006] This invention aims to overcome the problems of high cost, complicated process and limited source of catalysts in existing waste plastic catalytic cracking technologies, and to provide a solution that combines catalytic performance and economy.

[0007] To achieve the above objectives, the present invention provides an industrial solid waste-based carbon powder catalyst, wherein the industrial solid waste-based carbon powder catalyst comprises industrial solid waste-based carbon powder, and the industrial solid waste-based carbon powder comprises carbon, oxygen, silicon, aluminum, iron, calcium, magnesium, nitrogen, hydrogen and titanium.

[0008] The industrial solid waste-based carbon powder catalyst of this invention comprises silicon and aluminum elements that effectively reduce the pyrolysis activation energy, enabling the reaction to proceed efficiently at a relatively low temperature of 300-400°C; iron element participates in the hydrogen transfer process, helping to stabilize free radical intermediates and regulate product distribution, thereby improving the selectivity of light alkanes and olefins; alkaline earth metal components such as calcium and magnesium can capture HCl and SO2 released during the pyrolysis process in situ. X It can purify oil and gas products by removing acidic gases, reduce equipment corrosion, and improve oil quality. Titanium enhances the thermal stability and active site dispersion of the catalyst by adjusting the electronic structure and surface functional groups of the carbon matrix. At the same time, the porous biochar framework composed of carbon and non-metallic elements such as oxygen, nitrogen, and hydrogen not only provides abundant adsorption-reaction interfaces, but also facilitates reactant diffusion and product desorption, effectively inhibiting coke formation.

[0009] According to an embodiment of the present invention, the components of the industrial solid waste-based carbon powder, by mass fraction, include: 23-25% carbon, 22-25% oxygen, 17-20% silicon, 8-11% aluminum, 4-5% iron, 1-2% calcium, 0.5-1% magnesium, 0.5-1% nitrogen, 0.3-0.8% hydrogen, and 0.2-0.6% titanium.

[0010] Under the above conditions, a highly efficient and synergistic catalytic system was constructed, achieving low-temperature and high-efficiency pyrolysis. The precisely controlled multi-element composition works synergistically at multiple levels, including acid-base synergy, free radical regulation, gas purification, and pore structure optimization. This enables industrial solid waste-based carbon powder to achieve a comprehensive catalytic effect of high light oil yield from waste plastics, low gas / coke by-products, and good oil quality without complex modification or the addition of precious metals. This fully demonstrates the rationality of its mechanism and the advancement of its technology.

[0011] According to an embodiment of the present invention, the industrial solid waste-based carbon powder also includes biomass as a component.

[0012] According to an embodiment of the present invention, the biomass, by mass fraction, is 50-60% of the industrial solid waste-based carbon powder; the biomass includes domestic solid waste.

[0013] In this invention, biomass refers to biodegradable organic waste generated from daily life, agricultural production, or food processing. Specifically, it includes, but is not limited to, kitchen waste, food scraps, garden trimmings, livestock and poultry manure, crop straw, and food processing waste—waste rich in organic matter. The aforementioned biomass typically contains organic components such as proteins, polysaccharides, fats, cellulose, hemicellulose, and lignin, and under suitable conditions, can be converted into functional materials or energy through biological or chemical pathways.

[0014] According to the embodiments of this application, the specific surface area of ​​the industrial solid waste-based carbon powder catalyst is 20~30 m² / g, the pore volume is 0.06~0.08 cm³ / g, and the average pore size is 10~15 nm; the industrial solid waste-based carbon powder catalyst is obtained by pyrolysis carbonization treatment of industrial solid waste; the pyrolysis carbonization treatment is a heat treatment process in which the temperature is raised to 400~650℃ at a heating rate of 10~20℃ / min under an inert atmosphere (such as nitrogen) and maintained for 0.5~1.5h.

[0015] The specific pore structure in this invention provides ample space for exposed surface active sites, enabling acidic centers formed by catalytic elements such as silicon, aluminum, and iron to effectively contact and activate polyolefin macromolecular chains. The mesoporous-dominated channel structure (average pore size 10-15 nm) facilitates the diffusion and mass transfer of high molecular weight plastic melts and intermediate pyrolysis products, preventing micropore blockage and significantly improving reaction efficiency. The appropriate pore volume ensures sufficient retention of reactants within the channels and catalytic time, while providing effective desorption channels for the light oil and gas generated from pyrolysis, preventing secondary condensation reactions that generate coke. This hierarchical pore structure, in synergy with the acidic sites on the catalyst surface, not only promotes efficient C–C bond breaking but also effectively inhibits the formation of heavy aromatics and coke precursors, thereby achieving high light oil yield and low coke yield at lower temperatures.

[0016] According to an embodiment of the present invention, the components of the industrial solid waste-based carbon powder catalyst include [missing information], and the auxiliary catalyst includes at least one selected from aluminum oxide, synthetic zeolite, natural zeolite, amorphous silica, copper oxide, ferric oxide, and zinc oxide.

[0017] According to an embodiment of the present invention, the mass ratio of the industrial solid waste-based carbon powder to the auxiliary catalyst is 1 to 5:1.

[0018] Under the above conditions, industrial solid waste-based carbon powder, as the main component, effectively promotes the β-fracture and isomerization reaction of the polyolefin backbone. Simultaneously, its mesoporous structure provides efficient mass transfer channels for macromolecular plastic melts and pyrolysis intermediates, inhibiting the retention and condensation of coke precursors within the channels, thereby significantly reducing coke formation. Furthermore, the appropriate amount of auxiliary catalyst introduced supplements high-density, strongly acidic sites without disrupting the connectivity of the carbon powder channels, further enhancing the activation ability of C-C bonds.

[0019] The present invention also provides a method for preparing an industrial solid waste-based carbon powder catalyst, comprising: crushing and drying organic industrial solid waste, and then pyrolyzing and carbonizing it at a temperature of 300~500℃ to obtain an industrial solid waste-based carbon powder catalyst.

[0020] The present invention also provides a method for producing oil from waste plastics by pyrolysis, comprising the following steps: mixing waste plastics with the aforementioned industrial solid waste-based carbon powder catalyst and then carrying out a pyrolysis reaction at 300~400℃ for 0.5~2h.

[0021] According to an embodiment of the present invention, a method for producing oil from waste plastics by pyrolysis includes the following steps: mixing waste plastics with the industrial solid waste-based carbon powder catalyst and then carrying out a pyrolysis reaction at 300~400℃ and normal pressure for 0.5~2h; The batch reactor shall be equipped with either a mechanical stirring device or a magnetic stirring device, and shall also be equipped with a condensation reflux device and an exhaust gas treatment device.

[0022] According to an embodiment of the present invention, the mass ratio of the waste plastic to the industrial solid waste-based carbon powder catalyst is 2 to 10:1.

[0023] According to an embodiment of the present invention, the waste plastic includes at least one of polyethylene and polypropylene.

[0024] According to an embodiment of the present invention, the condensation reflux device has a condensation reflux temperature of 25~35°C.

[0025] The present invention has at least the following advantages: The industrial solid waste-based carbon powder provided by this invention has the advantages of wide availability, easy access, and low cost, and can be widely used in the catalytic thermal cracking of waste plastics. Specifically, the industrial solid waste-based carbon powder provided by this invention can directly catalytically crack at least one of polyethylene or polypropylene into saturated hydrocarbons, unsaturated olefins, and aromatic hydrocarbons containing some gasoline and diesel fractions. The cracking reaction temperature is lower than the direct cracking temperature of polypropylene (420℃) and polyethylene (460℃), resulting in lower energy consumption.

[0026] Compared to common catalysts such as metal oxides, silica, and zeolites, the industrial solid waste-based carbon powder provided by this invention has a lower gas yield, produces almost no coke, and retains most of the products as liquid products. Among them, the liquid products have a high content of light liquid fuels such as low-carbon olefins and alkanes.

[0027] The industrial solid waste-based carbon powder provided by this invention can be easily compounded with common metal oxides, silica, zeolite and other catalysts to improve the catalytic performance of industrial solid waste-based carbon powder catalysts.

[0028] The industrial solid waste-based carbon powder catalyst provided by this invention achieves high yields of liquid products from at least one of polyethylene or polypropylene. Under certain conditions, the industrial solid waste-based carbon powder achieves a maximum light oil yield of 80.4% for polyethylene, 72.1% for polypropylene, and 80.2% for mixed plastics; the industrial solid waste-based carbon powder and alumina composite catalyst achieve a maximum light oil yield of 82.7% for polyethylene and 75.3% for polypropylene; and the industrial solid waste-based carbon powder and artificial zeolite composite catalyst achieve a maximum light oil yield of 88.4% for polyethylene and 76.9% for polypropylene. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0030] Figure 1 SEM image of industrial solid waste-based carbon powder Figure 2 Process flow diagram for the application of this invention Figure 2 Labeling descriptions: 1. Heating plate; 2. Intermittent reactor; 3. Liquid product recovery device; 4. Tail gas treatment device; 5. Mechanical stirring device; 6. Gas outlet valve; 7. Condensation device.

[0031] The realization of the objective, functional characteristics and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0034] Example 1 This invention provides an industrial solid waste-based carbon powder catalyst and its application in plastic pyrolysis, specifically: 20g of the aforementioned industrial solid waste-based carbon powder (specific composition shown in Table 1, pore structure characteristics shown in Table 2) and 50g of polyethylene were placed in a 100mL batch reactor equipped with mechanical stirring, a condenser reflux device, and a tail gas treatment device for mixing. The target temperature was set to 350℃, the temperature control time was 30min, and the condensate temperature was room temperature (25℃). The mechanical stirring function was turned on when the plastic began to melt, and the speed was set to 1000rpm. After the reaction, gases below C5 were collected by the tail gas treatment device; low-boiling-point organic matter was condensed and the liquid product was collected; coke was retained in the reactor. The yields of the light liquid oil, coke, and gaseous products were calculated based on their respective masses. Qualitative and quantitative analysis of the liquid product composition distribution was performed using GC-MS.

[0035] The preparation method of industrial solid waste-based carbon powder catalyst is as follows: Domestic solid waste containing biomass components (mainly C, H, O, N, and small amounts of K, P, Mg, and Ca) was pre-treated by dehydration to a moisture content of less than 80%. This was then mixed with inorganic mineral components (industrial waste rich in elements listed in Table 1, such as incineration ash) as a precursor, with the biomass content controlled at 50 wt%. The precursor was further dried to a moisture content of less than 25%, pulverized to a particle size of less than 20 mesh, and then pyrolyzed and carbonized at 550°C under an inert atmosphere (such as nitrogen), with a heating rate controlled at 15°C / min and a holding time of 1.5 hours. After pyrolysis, the resulting solid product was immediately cooled rapidly using circulating water to remove some soluble salts and ash clogging the pores. After drying and sieving, the target carbon powder was obtained.

[0036] Similarly, by replacing the polyethylene with polypropylene and performing the same other operations, the catalytic activity results of 40wt% industrial solid waste-based carbon powder on polypropylene were obtained.

[0037] Similarly, by replacing the polyethylene with a mixed plastic in which the mass ratio of polyethylene to polypropylene is 0.5:1, 1:1, and 2:1 respectively, and performing the same other operations as above, the catalytic activity results of 40wt% industrial solid waste-based carbon powder on the mixed plastic were obtained.

[0038] Table 1. Element content of industrial solid waste-based carbon powder, wt% Table 2 Pore structure characteristics of industrial solid waste-based carbon powder Example 2 5g of the aforementioned industrial solid waste-based carbon powder (same as in Example 1) and 50g of polyethylene were placed in a 100mL intermittent reactor equipped with mechanical stirring, a reflux condenser, and a tail gas treatment device for mixing. The target temperature was set to 350℃, the temperature control time was 30min, and the condensate temperature was set to room temperature (25℃). When the plastic began to melt, the mechanical stirring function was turned on, and the speed was set to 1000rpm. After the reaction was completed, gases below C5 were collected by the tail gas treatment device; low-boiling-point organic matter was condensed and the liquid product was collected; coke was retained in the reactor. The yields of the light liquid oil, coke, and gaseous products were calculated based on their respective masses.

[0039] Similarly, by replacing the polyethylene with polypropylene and performing the same other operations, the catalytic activity results of 10wt% industrial solid waste-based carbon powder on polypropylene were obtained.

[0040] Example 3 10g of the aforementioned industrial solid waste-based carbon powder (same as in Example 1) and 50g of polyethylene were placed in a 100mL intermittent reactor equipped with mechanical stirring, a reflux condenser, and a tail gas treatment device for mixing. The target temperature was set to 350℃, the temperature control time to 30min, and the condensate temperature to room temperature (25℃). Once the plastic began to melt, the mechanical stirring function was activated at 1000rpm. After the reaction, gases below C5 were collected by the tail gas treatment device; low-boiling-point organic matter was condensed and the liquid product was collected; coke remained in the reactor. The yields of the light liquid oil, coke, and gaseous products were calculated based on their respective masses.

[0041] Similarly, by replacing the polyethylene with polypropylene and performing the same other operations, the catalytic activity results of 20wt% industrial solid waste-based carbon powder on polypropylene were obtained.

[0042] Example 4 30g of the aforementioned industrial solid waste-based carbon powder (same as in Example 1) and 50g of polyethylene were placed in a 100mL intermittent reactor equipped with mechanical stirring, a reflux condenser, and a tail gas treatment device for mixing. The target temperature was set to 350℃, the temperature control time was 30min, and the condensate temperature was set to room temperature (25℃). When the plastic began to melt, the mechanical stirring function was turned on, and the speed was set to 1000rpm. After the reaction was completed, gases below C5 were collected by the tail gas treatment device; low-boiling-point organic matter was condensed and the liquid product was collected; coke was retained in the reactor. The yields of the light liquid oil, coke, and gaseous products were calculated based on their respective masses.

[0043] Similarly, by replacing the polyethylene with polypropylene and performing the same other operations, the catalytic activity results of 60wt% industrial solid waste-based carbon powder on polypropylene were obtained.

[0044] Example 5 This embodiment illustrates the catalytic activity evaluation of the 1Al2O3 / 1C# used in this invention.

[0045] 10g of the above-mentioned industrial solid waste-based carbon powder (same as in Example 1) was mixed evenly with 10g of alumina to obtain 1Al2O3 / 1C#, and then mixed with 50g of polyethylene in a 100mL batch reactor equipped with mechanical stirring, a condenser reflux device, and a tail gas treatment device. The target temperature was set to 350℃, the temperature control time was 30min, and the condensate temperature was room temperature (25℃). When the plastic began to melt, the mechanical stirring function was turned on, and the speed was set to 1000rpm to start the reaction. After the reaction was completed, the gases below C5 were collected by the tail gas treatment device; the low-boiling-point organic matter was condensed and the liquid product was collected; the coke was retained in the reactor. The yields of the light liquid oil, coke, and gaseous products were calculated based on their respective masses.

[0046] Similarly, by replacing the polyethylene with polypropylene and performing the same other operations, the catalytic activity results of 1Al2O3 / 1C# for polypropylene were obtained.

[0047] Example 6 10g of the above-mentioned industrial solid waste-based carbon powder (same as in Example 1) was mixed evenly with 10g of artificial zeolite to obtain a 1:1 artificial zeolite / 1C# mixture. This mixture was then placed with 50g of polyethylene in a 100mL intermittent reactor equipped with mechanical stirring, a reflux condenser, and a tail gas treatment device. The target temperature was set to 350℃, the temperature control time to 30min, and the condensate temperature to room temperature (25℃). Once the plastic began to melt, the mechanical stirring function was activated at 1000rpm. After the reaction, gases below C5 were collected by the tail gas treatment device; low-boiling-point organic matter was condensed and the liquid product was collected; high-boiling-point coke was retained in the reactor. The yields of the resulting light liquid oil, coke oil, and coke were calculated based on their respective masses.

[0048] Similarly, by replacing the polyethylene with polypropylene and performing the same other operations, the catalytic activity results of 1 artificial zeolite / 1 C# for polypropylene were obtained.

[0049] Example 7 This embodiment provides another set of catalytic activity evaluations of industrial solid waste-based carbon powder to further illustrate the general effectiveness of industrial solid waste-based carbon powder within the range of element content.

[0050] The preparation method of industrial solid waste-based carbon powder is the same as in Example 1.

[0051] 20g of the aforementioned industrial solid waste-based carbon powder (specific composition shown in Table 3) and 50g of polyethylene were placed in a 100mL intermittent reactor equipped with mechanical stirring, a condenser reflux device, and a tail gas treatment device for mixing. The target temperature was set to 350℃, the temperature control time was 30min, and the condensate temperature was set to room temperature (25℃). The mechanical stirring function was turned on when the plastic began to melt, and the speed was set to 1000rpm. After the reaction was completed, gases below C5 were collected by the tail gas treatment device; low-boiling-point organic matter was condensed and the liquid product was collected; coke was retained in the reactor. The yields of the light liquid oil, coke, and gaseous products were calculated based on their respective masses.

[0052] Table 3. Element content of industrial solid waste-based carbon powder, wt% Comparative Example 1 50g of polyethylene was placed in a 100mL batch reactor equipped with mechanical stirring, a reflux condenser, and a tail gas treatment device for mixing. The target temperature was set to 350℃, the temperature control time to 30min, and the condensate temperature to room temperature (25℃). The mechanical stirring function was activated when the plastic began to melt, with a speed of 1000rpm. After the reaction, gases below C5 were collected by the tail gas treatment device; low-boiling-point organic matter was condensed and collected as liquid products; and coke was retained in the reactor. The yields of the light liquid oil, coke, and gaseous products were calculated based on their masses. Qualitative and quantitative analyses of the liquid product composition distribution were performed using GC-MS.

[0053] Similarly, by replacing the polyethylene with polypropylene and performing the same other operations as above, we obtained the result of direct pyrolysis of polypropylene.

[0054] Comparative Example 2 10g of alumina and 50g of polyethylene were mixed in a 100mL batch reactor equipped with mechanical stirring, a reflux condenser, and a tail gas treatment device. The target temperature was set to 350℃, the temperature control time to 30min, and the condensate temperature to room temperature (25℃). The mechanical stirring was activated at 1000rpm when the plastic began to melt. After the reaction, gases below C5 were collected by the tail gas treatment device; low-boiling-point organic matter was condensed and the liquid product was collected; coke was retained in the reactor. The yields of the light liquid oil, coke, and gaseous products were calculated based on their respective masses.

[0055] Similarly, by replacing polyethylene with polypropylene and performing the same other operations, the catalytic activity of aluminum oxide on polypropylene was obtained.

[0056] Comparative Example 3 The catalyst in Comparative Example 2 was replaced with copper oxide, and other operations were the same as in Comparative Example 2, to obtain the catalytic activity results of copper oxide for polyethylene.

[0057] Similarly, by replacing polyethylene with polypropylene and performing the same other operations, the catalytic activity of copper oxide on polypropylene was obtained.

[0058] Comparative Example 4 The catalyst in Comparative Example 2 was replaced with ferric oxide, and other operations were the same as in Comparative Example 2. The catalytic activity results of ferric oxide for polyethylene were obtained.

[0059] Similarly, by replacing polyethylene with polypropylene and performing the same other operations, the catalytic activity results of ferric oxide for polypropylene were obtained.

[0060] Comparative Example 5 The catalyst in Comparative Example 2 was replaced with zinc oxide, and other operations were the same as in Comparative Example 2, to obtain the catalytic activity results of zinc oxide for polyethylene.

[0061] Similarly, by replacing polyethylene with polypropylene and performing the same other operations, the catalytic activity of zinc oxide on polypropylene was obtained.

[0062] Comparative Example 6 The catalyst in Comparative Example 2 was replaced with amorphous silica, and other operations were the same as in Comparative Example 2. The catalytic activity of amorphous silica for polyethylene was obtained.

[0063] Similarly, by replacing polyethylene with polypropylene and performing the same other operations, the catalytic activity of amorphous silica on polypropylene was obtained.

[0064] Comparative Example 7 The catalyst in Comparative Example 2 was replaced with natural zeolite, and other operations were the same as in Comparative Example 2. The catalytic activity results of natural zeolite for polyethylene were obtained.

[0065] Similarly, by replacing the polyethylene with polypropylene and performing the same other operations, the catalytic activity results of natural zeolite for polypropylene were obtained.

[0066] Comparative Example 8 The catalyst in Comparative Example 2 was replaced with artificial zeolite, and other operations were the same as in Comparative Example 2. The catalytic activity results of artificial zeolite for polyethylene were obtained.

[0067] Similarly, by replacing polyethylene with polypropylene and performing the same other operations, the catalytic activity of artificial zeolite catalysis on polypropylene was obtained.

[0068] Test Example 1 Tables 3-6 present the systematic test results of the thermal pyrolysis performance evaluation of polyethylene, polypropylene, and their mixtures under the same experimental conditions, considering different catalyst dosages and catalyst systems. Tables 3 and 4 show the gas yield, light liquid oil yield, and coke yield (unit: wt%) of polyethylene and polypropylene catalyzed by various catalysts, used to evaluate catalytic activity and product selectivity. Table 5 focuses on the pyrolysis effect of the industrial solid waste-based carbon powder of this invention in treating mixed plastics with different ratios (polypropylene:polyethylene = 2:1, 1:1, 1:2), reflecting its adaptability to complex waste plastic raw materials. Table 6 further analyzes the results using gas chromatography-mass spectrometry (GC-MS), as follows: Table 4. Yield of polyethylene catalyzed by catalyst (wt%) Table 5. Catalytic polypropylene cracking yield (wt%) Table 6. Pyrolysis yield of industrial solid waste-based carbon powder catalytic mixed plastics, wt% Table 7. Distribution of polyethylene cracking products catalyzed by some catalysts, wt% According to the experimental results in Table 4-5, the catalyst dosage is a key factor affecting the distribution of pyrolysis products. When the dosage is too low (10 wt%, Example 2), the light oil yield is low and the coke yield is high, reflecting insufficient catalytic activity. As the dosage increases, the light oil yield gradually increases, and coke formation is suppressed. However, excessive dosage (60 wt%, Example 4) will cause excessive cracking of the light oil, leading to an increase in gas yield. In summary, 40 wt% is the optimal dosage (Example 1), which can effectively suppress the formation of gas and coke while achieving a high light oil yield. Under the above conditions (Examples 1 and 7), industrial solid waste-based carbon powder can maintain stable catalytic performance within a wide range of elemental contents (as defined in claim 2).

[0069] Under the conditions described above (Example 1), the light oil yields of industrial solid waste-based carbon powder for polyethylene and polypropylene reached over 80% and 70%, respectively, exceeding the performance data of Comparative Examples 1-8. Furthermore, through compounding schemes, Examples 5 and 6 further improved the light oil yield in the system, demonstrating the effective synergistic catalytic effect of industrial solid waste-based carbon powder. Meanwhile, as shown in Table 6, industrial solid waste-based carbon powder can also achieve high light oil yields while maintaining low coke yields when processing complex raw materials such as polyethylene / polypropylene mixed plastics.

[0070] Furthermore, the product distribution results in Table 7 show that Example 1 effectively optimized the composition and structure of the pyrolysis products. This is mainly reflected in the increased yield of light fuel components such as alkanes and the suppression of the formation of heavy aromatics during the pyrolysis of polyethylene. Since oils with high aromatic content are prone to producing large amounts of carbon deposits and gums during combustion, causing environmental pollution, this catalyst helps to improve the combustion characteristics of waste plastic oil and achieve clean combustion of waste plastic oil.

[0071] In summary, the industrial solid waste-based carbon powder provided by this invention exhibits excellent catalytic performance in the pyrolysis of waste plastics: under suitable conditions, its oil yield for single-component polyethylene and polypropylene reaches as high as 80.4% and 72.1%, respectively. Even when processing complex polyethylene / polypropylene mixed plastics, it can maintain a high light oil yield and low coking rate. Furthermore, the industrial solid waste-based carbon powder can be easily compounded with materials such as alumina and artificial zeolite to flexibly adjust and enhance its catalytic performance. The light oil obtained from the pyrolysis of industrial solid waste-based carbon powder is of high quality and value. The raw materials for industrial solid waste-based carbon powder are widely available, and the preparation process is simple, ensuring low cost and ease of promotion of the technology.

[0072] The above technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. An industrial solid waste-based carbon powder catalyst, characterized in that, The industrial solid waste-based carbon powder catalyst comprises industrial solid waste-based carbon powder, which includes carbon, oxygen, silicon, aluminum, iron, calcium, magnesium, nitrogen, hydrogen, and titanium.

2. The industrial solid waste-based carbon powder catalyst according to claim 1, characterized in that, The components of the industrial solid waste-based carbon powder, by mass fraction, include: 23-25% carbon, 22-25% oxygen, 17-20% silicon, 8-11% aluminum, 4-5% iron, 1-2% calcium, 0.5-1% magnesium, 0.5-1% nitrogen, 0.3-0.8% hydrogen, and 0.2-0.6% titanium.

3. The industrial solid waste-based carbon powder catalyst for waste plastic pyrolysis according to claim 1, characterized in that, The industrial solid waste-based carbon powder also includes biomass as a component.

4. The industrial solid waste-based carbon powder catalyst according to claim 1, characterized in that, The industrial solid waste-based carbon powder catalyst has a specific surface area of ​​20~30 m² / g, a pore volume of 0.06~0.08 cm³ / g, and an average pore size of 10~15 nm.

5. The industrial solid waste-based carbon powder catalyst according to claim 1, characterized in that, The components of the industrial solid waste-based carbon powder catalyst include, and the auxiliary catalyst includes at least one of alumina, synthetic zeolite, natural zeolite, amorphous silica, copper oxide, ferric oxide, and zinc oxide.

6. The industrial solid waste-based carbon powder catalyst according to claim 5, characterized in that, The mass ratio of the industrial solid waste-based carbon powder to the auxiliary catalyst is 1~5:

1.

7. A method for preparing an industrial solid waste-based carbon powder catalyst as described in any one of claims 1 to 6, characterized in that, include: Organic industrial solid waste is crushed, dried, and then pyrolyzed at a temperature of 300~600℃ to obtain industrial solid waste-based carbon powder catalyst.

8. A method for producing oil from waste plastics by pyrolysis, characterized in that, Includes the following steps: Waste plastics are mixed with industrial solid waste-based carbon powder catalyst as described in any one of claims 1 to 6 and then subjected to a pyrolysis reaction at 300 to 400°C for 0.5 to 2 hours.

9. The method according to claim 8, characterized in that, The mass ratio of the waste plastic to the industrial solid waste-based carbon powder catalyst is 2~10:

1.

10. The method according to claim 8, characterized in that, The waste plastics include at least one of polyethylene and polypropylene.

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