Catalyst for preparing polyolefin plastic biodegradable carbon source and utilization method

Abstract

The invention belongs to the technical field of polyolefin plastic degradation, and particularly relates to a catalyst for preparing a polyolefin plastic biodegradable carbon source and a utilization method, and the method comprises the steps of catalyst preparation, plastic pyrolysis and algae culture with degradation liquid as a carbon source. The invention not only provides a high-efficiency and low-cost polyolefin plastic degradation method, but also realizes biological recycling of waste plastics by using the degradation product as a carbon source for culturing chlorella, and the implementation of the method not only contributes to reducing plastic pollution, but also can promote the development of sustainable biological energy sources, and has a wide application prospect. And a new solution is provided for environmental protection and resource recycling.

Description

Technical Field

[0001] The present invention relates to a catalyst for preparing a bioavailable carbon source for polyolefin plastics, and in particular to a catalyst for preparing a bioavailable carbon source for polyolefin plastics and a utilization method thereof. Background Art

[0002] Polyolefin plastics, including polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyvinyl chloride (PVC), are widely used worldwide and are among the most popular thermoplastics. These materials are renowned for their lightweight, durable, strong, and cost-effective properties, as well as their excellent electrical insulation and corrosion resistance. These advantages have made polyolefin plastics indispensable in a variety of key sectors, including food packaging, household goods, pipeline construction, construction, electronic equipment, agricultural mulch, and the automotive industry. However, the ubiquity of plastics has also created a significant environmental challenge: the disposal of waste plastics. It is estimated that nearly 60% of plastic products worldwide are landfilled or otherwise discarded in the natural environment without proper treatment. As saturated hydrocarbon compounds, polyolefin plastics lack reactive functional groups, resulting in extremely slow decomposition in the natural environment, exacerbating the problem of waste pollution. Therefore, the development of effective degradation and recycling technologies for polyolefin plastics has become an urgent global issue, attracting significant attention from both scientific and industrial communities. The degradation and recycling of polyolefin plastics are primarily achieved through physical and chemical methods. Physical recycling involves steps such as sorting, washing, drying, and high-temperature melting. While convenient, high-temperature treatment can lead to random polymer chain breakage, reducing the quality and applicability of the recycled plastic. Chemical recycling, on the other hand, decomposes polyolefins into small gaseous or liquid molecules through chemical reactions. These small molecules have the potential to be converted into petrochemical products or recycled plastic raw materials, achieving a win-win situation for both environmental and economic benefits. However, because polyolefins are composed of stable saturated C—H and C—C bonds, the activation and cleavage of these bonds require high energy. Furthermore, the pyrolysis process of polyolefins is difficult to control, often relying on catalysts or additives to regulate the reaction, lowering the cracking temperature, optimizing the product distribution, and increasing the selectivity and yield of the target product. Currently, zeolite molecular sieves and noble metal catalysts are commonly used catalysts for polyolefin degradation, capable of lowering the cracking temperature to approximately 200°C. Despite this, existing chemical recycling technologies still suffer from high costs, insufficient conversion efficiency, low selectivity, and limited product value. Therefore, developing new methods for the efficient and highly selective degradation of polyolefin plastics, while simultaneously achieving high-value catalyst recovery, is a pressing technical challenge. Chlorella utilizes the thermal degradation products of waste plastics as a carbon source, achieving the dual goals of environmental protection and resource recovery. By converting waste plastics into an organic carbon source for the algae to absorb and utilize, this process not only reduces environmental pollution from waste plastics but also promotes the production of biomass energy, achieving high-value utilization of waste. Furthermore, Chlorella growth consumes carbon dioxide, contributing to mitigating the greenhouse effect. Its biomass can be used as biofuel or feed, demonstrating the potential of a circular economy.

[0003] An invention has utilized mass-produced molten salt catalysts for the catalytic degradation of polyolefin plastics, producing highly active molten salt catalysts. Due to the inherently highly polar reaction environment of inorganic molten salts, they significantly increase the standard chemical potential and reactivity of non-ionic reactants such as polyolefins, further stabilizing the carbocation transition state, thereby lowering the total free energy barrier for C-C bond cleavage reactions and significantly improving the thermodynamic and kinetic reactivity of polyolefin catalytic cracking. The molten salt catalyst is mixed with crushed polyolefin plastic, followed by the addition of the additive KHCO₃. Heating for a period of time completes the degradation and upgrading of the polyolefin plastic. The technical principle is that the highly active chloroaluminate in the molten salt reacts electrophilically with the polyolefin to form a carbocation. This carbocation then undergoes hydrogen transfer, isomerization, and cyclization reactions to produce cyclic liquid cracking products consisting primarily of C₃-C₅ alkanes, primarily isobutane, and a small amount of adamantane. The additive KHCO₃ modulates the composition of the chloroaluminate's Lewis acid sites, promoting the catalytic cracking of the polyolefin, ultimately resulting in near-100% mass conversion of the polyolefin. Gas chromatography was used to qualitatively and quantitatively determine the content of the obtained gaseous product, and the mass conversion rate of the gaseous product was more than 90%; a thermogravimetric analyzer was used to evaluate the mass of the liquid product, and then a gas chromatography-mass spectrometry chromatograph was used to analyze the specific structure of the product, and the mass conversion rate of the liquid product was finally obtained to be 7%-14%, mainly containing C9-C14 unsaturated alkanes and C9-C14 cycloalkanes. In the invention, when preparing the molten salt catalyst, the auxiliary agent KHCO3 is mixed with anhydrous sodium chloride, anhydrous potassium chloride, and anhydrous aluminum chloride. The obtained molten salt catalyst is directly mixed with the crushed polyolefin plastic and then heated to react, which can also achieve the same technical effect of degrading polyolefin plastic. In the method of low-temperature catalytic degradation of polyolefin plastic of the present invention, low-temperature molten salt is used as a liquid catalyst and solvent to effectively increase the contact between the catalytic site and the plastic. The high ionic environment of the molten salt stabilizes the reacting carbon cations well and accelerates the mass transfer process, thereby effectively improving the catalytic efficiency and selectivity. The mass recovery rate for polyolefin plastic degradation and upgrading reaches over 99%. The reaction process requires no solvents, initiators, or phase transfer agents, and the degradation temperature is below 100°C, significantly reducing energy consumption and costs. The recovered molten salt catalyst can be reused for low-temperature catalytic degradation of polyolefin plastics. After five cycles, the mass conversion rate of the molten salt catalyst reaches over 97%.

[0004] Currently, in addition to high-temperature hydrogenolysis, ionic liquids are also used for plastic degradation. While high-temperature hydrogenolysis is an effective method for treating plastic waste, it faces challenges such as high energy consumption, high equipment costs, operational safety risks, potential byproduct generation, limited degradation selectivity, environmental impacts, technical complexity, economic feasibility, and raw material availability. These challenges limit its widespread application and require technological innovation and optimization to overcome. Ionic liquids are a class of room-temperature molten salts composed of organic cations and inorganic or organic anions. They have attracted attention for their low volatility, high thermal stability, and excellent solvent properties, showing particular promise in the field of plastic degradation. However, ionic liquids face numerous challenges in practical application. Their complex and costly synthesis process limits the economic viability of large-scale application. Furthermore, the difficulty in separating ionic liquids from plastic degradation products complicates recycling and reuse, further increasing overall costs. Although considered environmentally friendly, the long-term degradability and bioaccumulation of ionic liquids remain unclear. Ionic liquids may be inferior to some traditional thermochemical methods in terms of degradation efficiency, especially for recalcitrant plastics such as polyolefins. They typically require high-temperature or high-pressure reaction conditions, increasing energy consumption and equipment requirements. Furthermore, selectivity issues can complicate the degradation products, increasing the cost of subsequent separation and purification. While ionic liquids have low toxicity, some types may pose potential health and environmental risks. Technical challenges and costs should not be overlooked during the scale-up process from laboratory to industrial scale, as potential side reactions during the degradation process can affect the quality of the final product. Summary of the Invention

[0005] The main purpose of the present disclosure is to provide a catalyst and a method for preparing a bioavailable carbon source for polyolefin plastics, so as to effectively solve the problems raised by the inventors in the above background technology.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0007] A catalyst for preparing a bioavailable carbon source for polyolefin plastics and a method for utilizing the same, the method comprising the following steps:

[0008] S1: Preparation of catalyst. The steps for preparing the catalyst are as follows:

[0009] S11: Prepare 3.2 g of 2 mmol ZrOCl2·8H2O and 4.3 g of 0.01 mol Ce(NO3)3·6H2O, mix these two compounds with 60 mL of deionized water, and stir the mixture at 50 °C for 1 hour to ensure sufficient dissolution and mixing;

[0010] S12: adding aqueous ammonia to the mixed solution and adjusting the pH value to 10 to promote the formation of a precipitate, and continuing to stir the mixture for 3 hours to ensure that the aqueous ammonia reacts fully with the solution;

[0011] S13: The reaction mixture is centrifuged to wash the precipitate to remove unreacted reagents and by-products, and the precipitate is placed in an oven and dried at 110° C. for 10 hours to remove moisture;

[0012] S14: placing the dried precipitate in a muffle furnace and calcining it at 900° C. for 3 hours to form a desired catalyst precursor;

[0013] S15: After calcination, the catalyst precursor was mixed with a solution of 2 mmol nickel nitrate and cobalt nitrate, 10 ml ammonia was added, and the mixture was stirred and heated at 60° C. for 3 hours to achieve uniform distribution of metal ions;

[0014] S16: The reaction mixture is centrifuged to wash the precipitate to remove unreacted reagents and by-products, and the precipitate is placed in an oven and dried at 110° C. for 10 hours. Finally, the treated catalyst is calcined in a muffle furnace at 700° C. for 3 hours to form the final cerium zirconium oxide-bimetallic core-shell structure catalyst;

[0015] S2: pyrolysis of plastics;

[0016] S3: Using the degradation liquid as a carbon source to cultivate algae.

[0017] Preferably, the steps of the plastic pyrolysis process are as follows:

[0018] S21: Select a suitable catalyst, polypropylene (PP) plastic to be degraded, and water, and mix 0.2 g of the catalyst with 30 mg of the PP plastic and 30 mL of water in a certain proportion to ensure that the catalyst is evenly distributed in the mixture of the plastic and water;

[0019] S22: The mixed raw materials are placed in a reactor, ensuring that the reactor is sealed to prevent leakage of substances during the reaction process. The mixture is reacted at 140 degrees Celsius for 6 hours. During this time, the catalyst will promote the thermal decomposition of the polypropylene plastic, breaking it down into smaller molecules;

[0020] S23: After the reaction is completed, the reactor is closed and allowed to cool, and then the degradation products are taken out of the reactor and filtered and purified for further use or analysis;

[0021] S24: Perform chemical analysis on the degradation products to determine their composition and characteristics, and to evaluate the efficiency of the pyrolysis process and the potential application value of the products.

[0022] Preferably, in step three, the steps of using the degradation liquid as a carbon source to cultivate algae are as follows:

[0023] S31: collecting the degradation liquid obtained from the plastic pyrolysis process, and performing necessary pretreatment on the collected degradation liquid, such as filtering and sterilizing, to ensure that it is suitable for use as a culture medium;

[0024] The C7-C15 products in the degradation liquid account for 50-80%, mainly including esters and ethers such as C14H28, C7H10O2, C13H24O2, C13H24O6 and cycloalkanes.

[0025] S32: mixing the pretreated degradation liquid with other nutrients required for culturing Chlorella to prepare a culture medium suitable for the growth of Chlorella, inoculating Chlorella in the culture medium to ensure uniform distribution, and placing the inoculated culture medium under suitable environmental conditions, such as specific temperature, light, and pH value, to promote the growth of Chlorella;

[0026] S33: During the cultivation process, the growth of Chlorella was regularly observed, and its growth rate, morphological changes, etc. were recorded. The growth status of Chlorella was evaluated by measuring parameters such as biomass, chlorophyll content, and cell number.

[0027] S34: Compare the growth of Chlorella cultured using the degradation solution as a carbon source with that of the control group using a traditional carbon source, analyze the carbon source effect of the degradation solution, and record all data during the experiment in detail, including the concentration of the degradation solution, the growth parameters of Chlorella, etc. Based on the recorded data, analyze the effect of the degradation solution on the growth of Chlorella and evaluate its potential and effect as a carbon source.

[0028] In view of this, compared with the prior art, the beneficial effects of the present invention are:

[0029] (1) In the present application, not only can polyolefin plastics be efficiently degraded, but the solution obtained after degradation can be used as a carbon source for culturing Chlorella, thereby realizing the biological recycling of waste plastics.

[0030] (2) In the present application, its core-shell structure can effectively improve the stability and activity of the catalyst, so that polyolefin plastics can be effectively degraded at a lower temperature; secondly, the catalyst has good selectivity, can regulate the composition of the degradation products, and improve the yield of the target product; furthermore, due to the high thermal stability and corrosion resistance of zirconium oxide and zirconium oxide, the catalyst has a longer service life and lower maintenance cost.

[0031] (3) In the present application, the use of this catalyst in the degradation of polyolefin plastics can significantly reduce energy consumption and reaction temperature, lowering production costs while also minimizing thermal pollution to the environment. The degraded solution is rich in organic carbon and can be directly used to cultivate Chlorella vulgaris. This microalgae not only absorbs and converts this organic carbon, reducing environmental pollution, but also produces biomass during its growth process. This biomass can be further used to produce biofuels or other high-value-added chemicals, achieving resource recycling and promoting the development of sustainable bioenergy, thus providing a new solution for environmental protection and resource recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solution of the invention, the following is a brief introduction to the drawings required for the description of the specific implementation methods. Obviously, the drawings described below are only some embodiments of the invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0033] Figure 1 : Surface morphology of the catalyst in Example 1 under SEM;

[0034] Figure 2 : TEM image of the internal structure of the catalyst in Example 1;

[0035] Figure 3 : Schematic diagram of the carbon content and mass difference ratio in the solution changing with temperature under 1 g / L PP, 0.1 g catalyst and 6 h reaction time;

[0036] Figure 4 : Schematic diagram of the change of carbon content and mass difference ratio in the solution over time under the reaction conditions of 1 g / L PP, 0.1 g catalyst and 140 °C;

[0037] Figure 5 : Catalyst preparation flow chart;

[0038] Figure 6 : Degradation experiment flow chart;

[0039] Figure 7 : Biomass statistics diagram in Example 1;

[0040] Figure 8 : Biomass statistics diagram in Example 2;

[0041] Figure 9 : Biomass statistics diagram in Example 3;

[0042] Figure 10 : Biomass statistics diagram in Example 4;

[0043] Figure 11 : Biomass statistics diagram in Example 5;

[0044] Figure 12 : Biomass statistics diagram in Example 6;

[0045] Figure 13 : Biomass statistics diagram in Example 7;

[0046] Figure 14 : Biomass statistics diagram in Example 8;

[0047] Figure 15 : Biomass statistics diagram in Example 9;

[0048] Figure 16 : Biomass statistics diagram in Example 10;

[0049] Figure 17 : Biomass statistics diagram in Example 11;

[0050] Figure 18 : Biomass statistics diagram in Example 12;

[0051] Figure 19 : Biomass statistics chart in Example 13. DETAILED DESCRIPTION

[0052] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0053] like Figure 1-19 As shown, a catalyst for preparing a bioavailable carbon source for polyolefin plastics and a method for using the same, the method comprising the following steps:

[0054] S1: Preparation of catalyst. The steps for preparing the catalyst are as follows:

[0055] S11: Prepare 3.2 g of 2 mmol ZrOCl2·8H2O and 4.3 g of 0.01 mol Ce(NO3)3·6H2O, mix these two compounds with 60 mL of deionized water, and stir the mixture at 50 °C for 1 hour to ensure sufficient dissolution and mixing;

[0056] S12: adding aqueous ammonia to the mixed solution and adjusting the pH value to 10 to promote the formation of a precipitate, and continuing to stir the mixture for 3 hours to ensure that the aqueous ammonia reacts fully with the solution;

[0057] S13: The reaction mixture is centrifuged to wash the precipitate to remove unreacted reagents and by-products, and the precipitate is placed in an oven and dried at 110° C. for 10 hours to remove moisture;

[0058] S14: placing the dried precipitate in a muffle furnace and calcining it at 900° C. for 3 hours to form a desired catalyst precursor;

[0059] S15: After calcination, the catalyst precursor was mixed with a solution of 2 mmol nickel nitrate and cobalt nitrate, 10 ml ammonia was added, and the mixture was stirred and heated at 60° C. for 3 hours to achieve uniform distribution of metal ions;

[0060] S16: The reaction mixture is centrifuged to wash the precipitate to remove unreacted reagents and by-products, and the precipitate is placed in an oven and dried at 110° C. for 10 hours. Finally, the treated catalyst is calcined in a muffle furnace at 700° C. for 3 hours to form the final cerium zirconium oxide-bimetallic core-shell structure catalyst;

[0061] S2: pyrolysis of plastics;

[0062] S3: Using the degradation liquid as a carbon source to cultivate algae.

[0063] Specifically, the steps of the plastic pyrolysis process are as follows:

[0064] S21: Select a suitable catalyst, polypropylene (PP) plastic to be degraded, and water, and mix 0.2 g of the catalyst with 30 mg of the PP plastic and 30 mL of water in a certain proportion to ensure that the catalyst is evenly distributed in the mixture of the plastic and water;

[0065] S22: The mixed raw materials are placed in a reactor, ensuring that the reactor is sealed to prevent leakage of substances during the reaction process. The mixture is reacted at 140 degrees Celsius for 6 hours. During this time, the catalyst will promote the thermal decomposition of the polypropylene plastic, breaking it down into smaller molecules;

[0066] S23: After the reaction is completed, the reactor is closed and allowed to cool, and then the degradation products are taken out of the reactor and filtered and purified for further use or analysis;

[0067] S24: Perform chemical analysis on the degradation products to determine their composition and characteristics, and to evaluate the efficiency of the pyrolysis process and the potential application value of the products.

[0068] Specifically, in step 3, the steps of using the degradation liquid as a carbon source to cultivate algae are as follows:

[0069] S31: collecting the degradation liquid obtained from the plastic pyrolysis process, and performing necessary pretreatment on the collected degradation liquid, such as filtering and sterilizing, to ensure that it is suitable for use as a culture medium;

[0070] S32: mixing the pretreated degradation liquid with other nutrients required for culturing Chlorella to prepare a culture medium suitable for the growth of Chlorella, inoculating Chlorella in the culture medium to ensure uniform distribution, and placing the inoculated culture medium under suitable environmental conditions, such as specific temperature, light, and pH value, to promote the growth of Chlorella;

[0071] S33: During the cultivation process, the growth of Chlorella was regularly observed, and its growth rate, morphological changes, etc. were recorded. The growth status of Chlorella was evaluated by measuring parameters such as biomass, chlorophyll content, and cell number.

[0072] S34: Compare the growth of Chlorella cultured using the degradation solution as a carbon source with that of the control group using a traditional carbon source, analyze the carbon source effect of the degradation solution, and record all data during the experiment in detail, including the concentration of the degradation solution, the growth parameters of Chlorella, etc. Based on the recorded data, analyze the effect of the degradation solution on the growth of Chlorella and evaluate its potential and effect as a carbon source.

[0073] The specific implementation of this embodiment is as follows: The plastic pyrolysis process is a chemical recycling method that converts waste plastic into useful products. In this process, a carefully designed catalyst is mixed with polypropylene (PP) plastic and water and placed in a reactor. Under controlled temperature and pressure conditions, the substances in the reactor react at 100-150 degrees Celsius for 6 hours. The catalyst plays a crucial role in this process, reducing the activation energy of the reaction and accelerating the breakage of plastic molecules, thereby promoting the efficient degradation of polypropylene plastic. As the reaction proceeds, the long-chain molecules of polypropylene plastic are broken down into shorter segments under the action of the catalyst, ultimately converting them into various small-molecule hydrocarbons and other recyclable chemicals. These degradation products not only reduce the impact of plastic waste on the environment but can also be used as chemical raw materials to produce new plastics or other industrial products, achieving resource recycling. In addition, the water produced during the pyrolysis process helps control the reaction temperature and prevent overheating, and also helps to carry and separate the degradation products. By precisely controlling the reaction conditions, the composition of the degradation products can be optimized, improving the yield and quality of the target product. In summary, the plastic pyrolysis process is an effective technology for plastic waste treatment and resource recovery. By using appropriate catalysts and controlling reaction conditions, we are able to convert waste polypropylene plastic into valuable chemical feedstock, contributing to solving the plastic pollution problem and promoting sustainable development.

[0074] This invention represents an innovative advancement in the field of polyolefin plastic degradation technology, proposing a highly efficient method for catalytic degradation of polyolefin plastics at relatively low temperatures. This method not only significantly reduces energy consumption but also effectively converts polyolefin plastics into soluble organic carbon, which can then be used as a carbon source for cultivating Chlorella vulgaris, enabling the biorecycling and reuse of waste plastics. During the experiment, the carefully designed catalyst successfully degraded large-molecule polyolefin plastics into small-molecule organic compounds. Total organic carbon (TOC) and ion chromatography (IC) measurements revealed that 50-70% of the plastic was converted into water-soluble organic carbon, demonstrating the high efficiency of the degradation process. Further mass difference ratio analysis revealed that the degradation efficiency could reach 80-95%, further confirming the superiority of the method. Detailed analysis of the degradation products using gas chromatography-mass spectrometry (GC-MS) revealed the production of a variety of short-chain organic compounds. These short-chain organic compounds not only enriched the degradation product diversity but also provided a rich carbon source for subsequent Chlorella vulgaris cultivation.

[0075] In our Chlorella cultivation experiments, we found that the amount of carbon source added significantly impacts Chlorella growth. Both too much and too little carbon source impaired growth, while optimal growth was achieved when the carbon source was added in the right amount. This discovery provides us with an optimized carbon source addition strategy for efficient Chlorella cultivation.

[0076] The present invention provides the following embodiments:

[0077] Example 1

[0078] Mix 2 mmol of ZrOCl2·8H2O and 2 mmol of Ce(NO3)3·6H2O with 40 mL of deionized water. Stir the mixture at room temperature for 1 hour. Add ammonia to adjust the pH to 10 to completely precipitate Zr and Ce. Continue stirring for 3 hours. Centrifuge and wash the mixture, and dry the precipitate at 110°C for 10 hours. Calcinate at 700°C in a muffle furnace for 3 hours to obtain a zirconium-cerium bimetallic oxide. Add the above oxide powder to 30 mL of a mixed solution of 2 mmol of Co(NO3)2·6H2O and 2 mmol of Ni(NO3)2·6H2O, and heat at 60°C with stirring for 3 hours. Centrifuge and wash the mixture, and dry the precipitate at 110°C for 10 hours. Calcinate at 700°C in a muffle furnace for 3 hours and cool naturally to room temperature to obtain NiCo / ZrCeO x The microstructure of the catalyst is as follows: Figure 1 As shown, NiCo / ZrCeOx shows nano-spherical shape. Figure 2The internal structure of the catalyst is shown in the image. 0.1g of catalyst and 30mg of polypropylene (PP) were added to 30mL of water and mixed evenly. The mixture was then placed in an autoclave and reacted at 140°C for 6h to degrade and obtain a microbial carbon source solution. After filtration, it can be directly used to culture Chlorella. Chlorella was added to a conical flask containing 100mL of sterilized BL culture medium and 4mL of the above microbial carbon source solution was added. The initial algal cell concentration was 8.52×10 6 cells / mL, cultured at 25°C under a 12h (light): 12h (dark) environment for 10 days. The results showed that the cell count of algae cells cultured with the addition of microbial carbon source increased significantly compared to that without the addition of carbon source. Cell counts showed that the concentration of algae cells with the addition of carbon source increased to 8.46×10 after 10 days of culture. 7 cells / mL, and the biomass increased by 91.7% compared with that without adding carbon source. Figure 7 The biomass statistics graph in this example is shown.

[0079] Example 2

[0080] 2 mmol of ZrOCl2·8H2O and 2 mmol of Ce(NO3)3·6H2O were mixed with 40 mL of deionized water and stirred at room temperature for 1 hour. Ammonia was added to adjust the pH to 10 and stirring continued for 3 hours. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 10 hours. The mixture was then calcined at 700°C in a muffle furnace for 3 hours to obtain a zirconium-cerium bimetallic oxide. The above oxide powder was added to 30 mL of a mixed solution of 1 mmol of Co(NO3)2·6H2O and 1 mmol of Ni(NO3)2·6H2O and heated at 60°C for 3 hours with stirring. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 12 hours. The mixture was then calcined at 900°C in a muffle furnace for 3 hours to form a bimetallic core-shell catalyst. 0.1 g of the catalyst and 30 mg of polypropylene (PP) were added to 30 mL of water, mixed thoroughly, and placed in an autoclave at 140°C for 6 hours to produce a microbial carbon source solution. After filtration, the solution can be directly used for Chlorella cultivation. Chlorella was added to a conical flask containing 100 mL of sterilized BL medium, and 4 mL of the above-mentioned microbial carbon source solution was added. The initial algal cell concentration was 9.12 × 10 6 cells / mL, and cultured for 10 days at 25°C under a 12h (light): 12h (dark) environment. The results showed that the cell count of algae cells cultured with the addition of microbial carbon sources increased significantly compared to that without the addition of carbon sources. Cell counts showed that the concentration of algae cells with the addition of carbon sources increased to 8.23×10 after 10 days of culture. 7 cells / mL, and the biomass increased by 65.3% compared with that without adding carbon source. Figure 8 The biomass statistics graph in this example is shown.

[0081] Example 3

[0082] 2 mmol of ZrOCl2·8H2O and 2 mmol of Ce(NO3)3·6H2O were mixed with 40 mL of deionized water and stirred at room temperature for 1 hour. Ammonia was added to adjust the pH to 10 and stirring continued for 3 hours. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 10 hours. The mixture was then calcined at 700°C in a muffle furnace for 3 hours to obtain a zirconium-cerium bimetallic oxide. The above oxide powder was added to 30 mL of a mixed solution of 3 mmol of Co(NO3)2·6H2O and 3 mmol of Ni(NO3)2·6H2O and heated at 60°C for 3 hours with stirring. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 12 hours. The mixture was then calcined at 900°C in a muffle furnace for 3 hours to form a bimetallic core-shell catalyst. 0.1 g of the catalyst and 30 mg of polypropylene (PP) were added to 30 mL of water, mixed thoroughly, and placed in an autoclave at 140°C for 6 hours to degrade and obtain a microbial carbon source solution. After filtration, it can be directly used for Chlorella cultivation. Chlorella was added to a conical flask containing 100 mL of sterilized BL medium, and 4 mL of the above-mentioned microbial carbon source solution was added. The initial algal cell concentration was 8.66 × 10 6 cells / mL, and cultured for 10 days at 25°C under a 12h (light): 12h (dark) environment. The results showed that the cell count of algae cells cultured with the addition of microbial carbon sources increased significantly compared to that without the addition of carbon sources. Cell counts showed that the algae cell concentration with the addition of carbon sources increased to 8.96×10 after 10 days of culture. 7 cells / mL, and the biomass increased by 84.9% compared with that without adding carbon source. Figure 9 The biomass statistics graph in this example is shown.

[0083] Example 4

[0084] 2 mmol of ZrOCl2·8H2O and 1 mmol of Ce(NO3)3·6H2O were mixed with 40 mL of deionized water and stirred at room temperature for 1 hour. Ammonia was added to adjust the pH to 10 and stirring continued for 3 hours. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 10 hours. The mixture was then calcined at 700°C in a muffle furnace for 3 hours to obtain a zirconium-cerium bimetallic oxide. The above oxide powder was added to 30 mL of a mixed solution of 2 mmol of Co(NO3)2·6H2O and 2 mmol of Ni(NO3)2·6H2O and heated at 60°C for 3 hours with stirring. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 12 hours. The mixture was then calcined at 900°C in a muffle furnace for 3 hours to form a bimetallic core-shell catalyst. 0.1 g of the catalyst and 30 mg of polypropylene (PP) were added to 30 mL of water, mixed thoroughly, and placed in an autoclave at 140°C for 6 hours to degrade and obtain a microbial carbon source solution. After filtration, the solution can be directly used for Chlorella cultivation. Chlorella was added to a conical flask containing 100 mL of sterilized BL medium, and 4 mL of the above-mentioned microbial carbon source solution was added. The initial algal cell concentration was 8.86 × 10 6 cells / mL, cultured for 10 days at 25°C under a 12h (light): 12h (dark) environment. The results showed that the cell count of algae cells cultured with the addition of microbial carbon sources increased significantly compared to that without the addition of carbon sources. Cell counts showed that the cell concentration of algae cells with the addition of carbon sources increased to 9.26×10 after 10 days of culture. 7 cells / mL, and the biomass increased by 81.4% compared with that without adding carbon source. Figure 10 The biomass statistics graph in this example is shown.

[0085] Example 5

[0086] 2 mmol of ZrOCl2·8H2O and 2 mmol of Ce(NO3)3·6H2O were mixed with 40 mL of deionized water and stirred at room temperature for 1 hour. Ammonia was added to adjust the pH to 10 and stirring continued for 3 hours. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 10 hours. The mixture was then calcined at 700°C in a muffle furnace for 3 hours to obtain a zirconium-cerium bimetallic oxide. The above oxide powder was added to 30 mL of a mixed solution of 2 mmol of Co(NO3)2·6H2O and 2 mmol of Ni(NO3)2·6H2O and heated at 60°C for 3 hours with stirring. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 12 hours. The mixture was then calcined at 900°C in a muffle furnace for 3 hours to form a bimetallic core-shell catalyst. 0.1 g of the catalyst and 30 mg of polypropylene (PP) were added to 30 mL of water, mixed thoroughly, and placed in an autoclave at 140°C for 6 hours to degrade and obtain a microbial carbon source solution. After filtration, the solution can be directly used for Chlorella cultivation. Chlorella was added to a conical flask containing 100 mL of sterilized BL medium, and 2 mL of the above-mentioned microbial carbon source solution was added. The initial algal cell concentration was 8.77 × 10 6 cells / mL, cultured at 25°C under a 12h (light): 12h (dark) environment for 10 days. The results showed that the cell count of algae cells cultured with the addition of microbial carbon source increased significantly compared to that without the addition of carbon source. Cell counts showed that the cell concentration of algae cells with the addition of carbon source increased to 9.46×10 after 10 days of culture. 7 cells / mL, and the biomass increased by 61.7% compared with that without adding carbon source. Figure 11 The biomass statistics graph in this example is shown.

[0087] Example 6

[0088] 2 mmol of ZrOCl2·8H2O and 2 mmol of Ce(NO3)3·6H2O were mixed with 40 mL of deionized water and stirred at room temperature for 1 hour. Ammonia was added to adjust the pH to 10 and stirring continued for 3 hours. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 10 hours. The mixture was then calcined at 700°C in a muffle furnace for 3 hours to obtain a zirconium-cerium bimetallic oxide. The above oxide powder was added to 30 mL of a mixed solution of 2 mmol of Co(NO3)2·6H2O and 2 mmol of Ni(NO3)2·6H2O and heated at 60°C for 3 hours with stirring. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 12 hours. The mixture was then calcined at 900°C in a muffle furnace for 3 hours to form a bimetallic core-shell catalyst. 0.1 g of the catalyst and 30 mg of polypropylene (PP) were added to 30 mL of water, mixed thoroughly, and placed in an autoclave at 130°C for 6 hours to produce a microbial carbon source solution. After filtration, the solution can be directly used for Chlorella cultivation. Chlorella was added to a conical flask containing 100 mL of sterilized BL medium, and 4 mL of the above-mentioned microbial carbon source solution was added. The initial algal cell concentration was 7.92 × 10 6 cells / mL, and cultured for 10 days at 25°C under a 12h (light): 12h (dark) environment. The results showed that the cell count of algae cells cultured with the addition of microbial carbon sources increased significantly compared to that without the addition of carbon sources. Cell counts showed that the algae cell concentration with the addition of carbon sources increased to 8.47×10 after 10 days of culture. 7 cells / mL, and the biomass increased by 73.4% compared with that without adding carbon source. Figure 12 The biomass statistics graph in this example is shown.

[0089] Example 7

[0090] 2 mmol of ZrOCl2·8H2O and 2 mmol of Ce(NO3)3·6H2O were mixed with 40 mL of deionized water and stirred at room temperature for 1 hour. Ammonia was added to adjust the pH to 10 and stirring continued for 3 hours. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 10 hours. The mixture was then calcined at 700°C in a muffle furnace for 3 hours to obtain a zirconium-cerium bimetallic oxide. The above oxide powder was added to 30 mL of a mixed solution of 2 mmol of Co(NO3)2·6H2O and 2 mmol of Ni(NO3)2·6H2O and heated at 60°C for 3 hours with stirring. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 12 hours. The mixture was then calcined at 900°C in a muffle furnace for 3 hours to form a bimetallic core-shell catalyst. 0.1 g of the catalyst and 30 mg of polypropylene (PP) were added to 30 mL of water, mixed thoroughly, and placed in an autoclave. The mixture was reacted at 120°C for 6 hours to degrade and obtain a microbial carbon source solution. After filtration, it can be directly used for Chlorella cultivation. Chlorella was added to a conical flask containing 100 mL of sterilized BL medium, and 4 mL of the above-mentioned microbial carbon source solution was added. The initial algal cell concentration was 8.62 × 10 6 cells / mL, and cultured for 10 days at 25°C under a 12h (light): 12h (dark) environment. The results showed that the cell count of algae cells cultured with the addition of microbial carbon sources increased significantly compared to that without the addition of carbon sources. Cell counts showed that the algae cell concentration of the algae cultured with the addition of carbon sources increased to 6.21×10 after 10 days of culture. 7 cells / mL, and the biomass increased by 48.9% compared with that without adding carbon source. Figure 13 The biomass statistics graph in this example is shown.

[0091] Example 8

[0092] 2 mmol of ZrOCl2·8H2O and 2 mmol of Ce(NO3)3·6H2O were mixed with 40 mL of deionized water and stirred at room temperature for 1 hour. Ammonia was added to adjust the pH to 10 and stirring continued for 3 hours. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 10 hours. The mixture was then calcined at 700°C in a muffle furnace for 3 hours to obtain a zirconium-cerium bimetallic oxide. The above oxide powder was added to 30 mL of a mixed solution of 2 mmol of Co(NO3)2·6H2O and 2 mmol of Ni(NO3)2·6H2O and heated at 60°C for 3 hours with stirring. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 12 hours. The mixture was then calcined at 900°C in a muffle furnace for 3 hours to form a bimetallic core-shell catalyst. 0.1 g of the catalyst and 30 mg of polypropylene (PP) were added to 30 mL of water, mixed thoroughly, and placed in an autoclave at 140°C for 5 hours to degrade and obtain a microbial carbon source solution. After filtration, the solution can be directly used for Chlorella cultivation. Chlorella was added to a conical flask containing 100 mL of sterilized BL medium, and 4 mL of the above-mentioned microbial carbon source solution was added. The initial algal cell concentration was 8.22 × 10 6 cells / mL, cultured at 25°C under a 12h (light): 12h (dark) environment for 10 days. The results showed that the cell count of algae cells cultured with the addition of microbial carbon source increased significantly compared to that without the addition of carbon source. Cell counts showed that the algae cell concentration of the algae cultured with the addition of carbon source increased to 7.23×10 after 10 days of culture. 7 cells / mL, and the biomass increased by 62.9% compared with that without adding carbon source. Figure 14 The biomass statistics graph in this example is shown.

[0093] Embodiment 9

[0094] 2 mmol of ZrOCl2·8H2O and 2 mmol of Ce(NO3)3·6H2O were mixed with 40 mL of deionized water and stirred at room temperature for 1 hour. Ammonia was added to adjust the pH to 10 and stirring continued for 3 hours. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 10 hours. The mixture was then calcined at 700°C in a muffle furnace for 3 hours to obtain a zirconium-cerium bimetallic oxide. The above oxide powder was added to 30 mL of a mixed solution of 2 mmol of Co(NO3)2·6H2O and 2 mmol of Ni(NO3)2·6H2O and heated at 60°C for 3 hours with stirring. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 12 hours. The mixture was then calcined at 900°C in a muffle furnace for 3 hours to form a bimetallic core-shell catalyst. 0.1 g of the catalyst and 30 mg of polypropylene (PP) were added to 30 mL of water, mixed thoroughly, and placed in an autoclave at 140°C for 4 hours to degrade and obtain a microbial carbon source solution. After filtration, the solution can be directly used for Chlorella cultivation. Chlorella was added to a conical flask containing 100 mL of sterilized BL medium, and 4 mL of the above-mentioned microbial carbon source solution was added. The initial algal cell concentration was 7.62 × 10 6 cells / mL, cultured at 25°C under a 12h (light): 12h (dark) environment for 10 days. The results showed that the cell count of algae cells cultured with the addition of microbial carbon source increased significantly compared to that without the addition of carbon source. Cell counts showed that the algae cell concentration of the algae cultured with the addition of carbon source increased to 6.13×10 after 10 days of culture. 7 cells / mL, and the biomass increased by 48.1% compared with that without adding carbon source. Figure 15 The biomass statistics graph in this example is shown.

[0095] Example 10

[0096] 2 mmol of ZrOCl2·8H2O and 2 mmol of Ce(NO3)3·6H2O were mixed with 40 mL of deionized water and stirred at room temperature for 1 hour. Ammonia was added to adjust the pH to 10 and stirring continued for 3 hours. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 10 hours. The mixture was then calcined at 700°C in a muffle furnace for 3 hours to obtain a zirconium-cerium bimetallic oxide. The above oxide powder was added to 30 mL of a mixed solution of 2 mmol of Co(NO3)2·6H2O and 2 mmol of Ni(NO3)2·6H2O and heated at 60°C for 3 hours with stirring. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 12 hours. The mixture was then calcined at 900°C in a muffle furnace for 3 hours to form a bimetallic core-shell catalyst. 0.1 g of the catalyst and 30 mg of polypropylene (PP) were added to 30 mL of water, mixed thoroughly, and placed in an autoclave at 140°C for 7 hours to degrade and obtain a microbial carbon source solution. After filtration, the solution can be directly used for Chlorella cultivation. Chlorella was added to a conical flask containing 100 mL of sterilized BL medium, and 4 mL of the above-mentioned microbial carbon source solution was added. The initial algal cell concentration was 8.81 × 10 6 cells / mL, and cultured for 10 days at 25°C under a 12h (light): 12h (dark) environment. The results showed that the cell count of algae cells cultured with the addition of microbial carbon sources increased significantly compared to that without the addition of carbon sources. Cell counts showed that the concentration of algae cells with the addition of carbon sources increased to 8.23×10 after 10 days of culture. 7 cells / mL, and the biomass increased by 82.4% compared with that without adding carbon source. Figure 16 The biomass statistics graph in this example is shown.

[0097] Example 11

[0098] 2 mmol of ZrOCl2·8H2O and 2 mmol of Ce(NO3)3·6H2O were mixed with 40 mL of deionized water and stirred at room temperature for 1 hour. Ammonia was added to adjust the pH to 10 and stirring continued for 3 hours. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 10 hours. The mixture was then calcined at 700°C in a muffle furnace for 3 hours to obtain a zirconium-cerium bimetallic oxide. The above oxide powder was added to 30 mL of a mixed solution of 2 mmol of Co(NO3)2·6H2O and 2 mmol of Ni(NO3)2·6H2O and heated at 60°C for 3 hours with stirring. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 12 hours. The mixture was then calcined at 900°C in a muffle furnace for 3 hours to form a bimetallic core-shell catalyst. 0.1 g of the catalyst and 30 mg of polypropylene (PP) were added to 30 mL of water, mixed thoroughly, and placed in an autoclave at 140°C for 4 hours to degrade and obtain a microbial carbon source solution. After filtration, the solution can be directly used for Chlorella cultivation. Chlorella was added to a conical flask containing 100 mL of sterilized BL medium, and 4 mL of the above-mentioned microbial carbon source solution was added. The initial algal cell concentration was 8.53 × 10 6 cells / mL, cultured for 10 days at 25°C under a 12h (light): 12h (dark) environment. The results showed that the cell count of algae cells cultured with the addition of microbial carbon sources increased significantly compared to that without the addition of carbon sources. Cell counts showed that the algae cell concentration with the addition of carbon sources increased to 5.83×10 after 10 days of culture. 7 cells / mL, and the biomass increased by 58.1% compared with that without adding carbon source. Figure 17 The biomass statistics graph in this example is shown.

[0099] Example 12

[0100] 2 mmol of ZrOCl2·8H2O and 2 mmol of Ce(NO3)3·6H2O were mixed with 40 mL of deionized water and stirred at room temperature for 1 hour. Ammonia was added to adjust the pH to 10 and stirring continued for 3 hours. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 10 hours. The mixture was then calcined at 900°C in a muffle furnace for 3 hours to obtain a zirconium-cerium bimetallic oxide. The above oxide powder was added to 30 mL of a mixed solution of 2 mmol of Co(NO3)2·6H2O and 2 mmol of Ni(NO3)2·6H2O and heated at 60°C for 3 hours with stirring. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 10 hours. The mixture was then calcined at 700°C in a muffle furnace for 3 hours to form a bimetallic core-shell catalyst. 0.05 g of the catalyst and 30 mg of polypropylene (PP) were added to 30 mL of water, mixed thoroughly, and placed in an autoclave at 140°C for 6 hours to degrade and obtain a microbial carbon source solution. After filtration, the solution can be directly used for Chlorella cultivation. Chlorella was added to a conical flask containing 100 mL of sterilized BL medium, and 4 mL of the above-mentioned microbial carbon source solution was added. The initial algal cell concentration was 8.12 × 10 6 cells / mL, and cultured for 10 days at 25°C under a 12h (light): 12h (dark) environment. The results showed that the cell count of algae cells cultured with the addition of microbial carbon sources increased significantly compared to that of cells cultured without the addition of carbon sources. Cell counts showed that the cell concentration of algae cells with the addition of carbon sources increased to 7.37×10 after 10 days of culture. 7 cells / mL, and the biomass increased by 56.7% compared with that without adding carbon source. Figure 18 The biomass statistics graph in this example is shown.

[0101] Example 13

[0102] 2 mmol of ZrOCl2·8H2O and 2 mmol of Ce(NO3)3·6H2O were mixed with 40 mL of deionized water and stirred at room temperature for 1 hour. Ammonia was added to adjust the pH to 10 and stirring continued for 3 hours. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 10 hours. The mixture was then calcined at 900°C in a muffle furnace for 3 hours to obtain a zirconium-cerium bimetallic oxide. The above oxide powder was added to 30 mL of a mixed solution of 2 mmol of Co(NO3)2·6H2O and 2 mmol of Ni(NO3)2·6H2O and heated at 60°C for 3 hours with stirring. The mixture was centrifuged and washed, and the precipitate was dried at 110°C for 10 hours. The mixture was then calcined at 700°C in a muffle furnace for 3 hours to form a bimetallic core-shell catalyst. 0.2 g of the catalyst and 30 mg of polypropylene (PP) were added to 30 mL of water, mixed thoroughly, and placed in an autoclave at 140°C for 6 hours to degrade and obtain a microbial carbon source solution. After filtration, the solution can be directly used for Chlorella cultivation. Chlorella was added to a conical flask containing 100 mL of sterilized BL medium, and 4 mL of the above-mentioned microbial carbon source solution was added. The initial algal cell concentration was 8.35 × 10 6 cells / mL, and cultured for 10 days at 25°C under a 12h (light): 12h (dark) environment. The results showed that the cell count of algae cells cultured with the addition of microbial carbon sources increased significantly compared to that without the addition of carbon sources. Cell counts showed that the algae cell concentration with the addition of carbon sources increased to 8.36×10 after 10 days of culture. 7 cells / mL, and the biomass increased by 85.6% compared with that without adding carbon source. Figure 19 The biomass statistics graph in this example is shown.

[0103] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0104] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A catalyst for preparing a bioavailable carbon source for polyolefin plastics and a method for utilizing the same, characterized in that: The method comprises the following steps: S1: Preparation of catalyst. The steps for preparing the catalyst are as follows: S11: Prepare 3.2 g of 2 mmol ZrOCl2·8H2O and 4.3 g of 0.01 mol Ce(NO3)3·6H2O, mix these two compounds with 60 mL of deionized water, and stir the mixture at 50 °C for 1 hour to ensure sufficient dissolution and mixing; S12: adding aqueous ammonia to the mixed solution and adjusting the pH value to 10 to promote the formation of a precipitate, and continuing to stir the mixture for 3 hours to ensure that the aqueous ammonia reacts fully with the solution; S13: The reaction mixture is centrifuged to wash the precipitate to remove unreacted reagents and by-products, and the precipitate is placed in an oven and dried at 110° C. for 10 hours to remove moisture; S14: placing the dried precipitate in a muffle furnace and calcining it at 900° C. for 3 hours to form a desired catalyst precursor; S15: After calcination, the catalyst precursor was mixed with a solution of 2 mmol nickel nitrate and cobalt nitrate, 10 ml ammonia was added, and the mixture was stirred and heated at 60° C. for 3 hours to achieve uniform distribution of metal ions; S16: The reaction mixture is centrifuged to wash the precipitate to remove unreacted reagents and by-products, and the precipitate is placed in an oven and dried at 110° C. for 10 hours. Finally, the treated catalyst is calcined in a muffle furnace at 700° C. for 3 hours to form the final cerium zirconium oxide-bimetallic core-shell structure catalyst; S2: pyrolysis of plastics; S3: Using the degradation liquid as a carbon source to cultivate algae.

2. A catalyst for preparing a bioavailable carbon source for polyolefin plastics and a method for utilizing the same according to claim 1, characterized in that: The steps of the plastic pyrolysis process are as follows: S21: Select a suitable catalyst, polypropylene (PP) plastic to be degraded, and water, and mix 0.2 g of the catalyst with 30 mg of the PP plastic and 30 mL of water in a certain proportion to ensure that the catalyst is evenly distributed in the mixture of the plastic and water; S22: The mixed raw materials are placed in a reactor, ensuring that the reactor is sealed to prevent leakage of substances during the reaction process. The mixture is reacted at 140 degrees Celsius for 6 hours. During this time, the catalyst will promote the thermal decomposition of the polypropylene plastic, breaking it down into smaller molecules; S23: After the reaction is completed, the reactor is closed and allowed to cool, and then the degradation products are taken out of the reactor and filtered and purified for further use or analysis; S24: Perform chemical analysis on the degradation products to determine their composition and characteristics, and to evaluate the efficiency of the pyrolysis process and the potential application value of the products.

3. A catalyst for preparing a bioavailable carbon source for polyolefin plastics and a method for utilizing the same according to claim 2, characterized in that: In step 3, the steps of using the degradation liquid as a carbon source to cultivate algae are as follows: S31: collecting the degradation liquid obtained from the plastic pyrolysis process, and performing necessary pretreatment on the collected degradation liquid, such as filtering and sterilizing, to ensure that it is suitable for use as a culture medium; S32: mixing the pretreated degradation liquid with other nutrients required for culturing Chlorella to prepare a culture medium suitable for the growth of Chlorella, inoculating Chlorella in the culture medium to ensure uniform distribution, and placing the inoculated culture medium under suitable environmental conditions, such as specific temperature, light, and pH value, to promote the growth of Chlorella; S33: During the cultivation process, the growth of Chlorella was regularly observed, and its growth rate, morphological changes, etc. were recorded. The growth status of Chlorella was evaluated by measuring parameters such as biomass, chlorophyll content, and cell number. S34: Compare the growth of Chlorella cultured using the degradation solution as a carbon source with that of the control group using a traditional carbon source, analyze the carbon source effect of the degradation solution, and record all data during the experiment in detail, including the concentration of the degradation solution, the growth parameters of Chlorella, etc. Based on the recorded data, analyze the effect of the degradation solution on the growth of Chlorella and evaluate its potential and effect as a carbon source.

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