A method for preparing olefins from waste plastics catalyzed by pyrolytic carbon-based calcium material
By loading alkaline earth metal calcium onto pyrolysis carbon-based calcium catalysts to form composite catalysts, the problems of low recycling efficiency of waste plastics and insufficient catalyst selection are solved, and the efficient preparation of olefins is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGZHOU INST OF ENERGY CONVERSION CHINESE ACAD OF SCI
- Filing Date
- 2024-12-31
- Publication Date
- 2026-06-30
AI Technical Summary
In existing technologies, the recycling of waste plastics is inefficient and causes secondary pollution. In catalytic pyrolysis technology, the selection of catalysts is insufficient, making it difficult to effectively improve the yield and quality of olefins produced from waste plastics.
Pyrolytic carbon-based calcium material was used as a catalyst support, and alkaline earth metal calcium was loaded by wet impregnation to form a composite catalyst. The porous structure and catalytic activity of CaO/Ca(OH)2 were utilized to improve the olefin yield.
It improved the yield and quality of olefins from waste plastics, realizing the resource utilization of agricultural solid waste. The olefin yield reached 93.75%, and the olefin content was 58.87%.
Smart Images
Figure CN122298386A_ABST
Abstract
Description
Technical fields:
[0001] This invention relates to the field of solid waste treatment technology, specifically to a method for preparing olefins from waste plastics using pyrolysis of carbon-based calcium materials. Background technology:
[0002] Plastics are widely used in packaging, the automotive industry, construction, and the manufacture of everyday consumer goods; however, their non-degradable nature leads to serious environmental problems. Traditional methods of recycling waste plastics, such as mechanical recycling, incineration, and landfill, are inefficient and cause secondary pollution. Pyrolysis technology can treat waste plastics and enable their resource utilization. Compared with pyrolysis alone, catalytic pyrolysis is more conducive to improving the yield and quality of the product oil. In this reaction, the selection of the catalyst material is particularly important. There is an urgent need to develop a new catalyst. Summary of the Invention:
[0003] This invention solves the problems existing in the prior art and provides a method for preparing olefins from waste plastics by using pyrolytic carbon-based calcium materials. This invention utilizes the carrier characteristics of pyrolytic carbon and the activity of alkaline earth metals to improve the performance of olefin preparation from waste plastics.
[0004] The first objective of this invention is to provide a method for preparing a pyrolytic carbon-based calcium material catalyst, comprising the following steps:
[0005] (1) Under an inert atmosphere, agricultural and forestry solid waste is pyrolyzed at 600℃-900℃ for 1-3 hours to obtain solid waste pyrolysis char;
[0006] (2) Using solid waste pyrolysis carbon as a carrier and alkaline earth metal calcium as an active material, the two materials are mixed evenly in a solvent, dried, and the resulting solid material is calcined under an inert atmosphere to obtain the pyrolysis carbon-based calcium material catalyst.
[0007] This invention utilizes pyrolysis char from solid waste as a catalyst support, and prepares a novel composite catalyst by uniformly loading metallic Ca onto the surface of the support using a wet impregnation method. After the high-temperature pyrolysis reaction, the surface of the corn stalk pyrolysis char undergoes pyrolysis, forming a regular porous structure, which provides important surface area and tubular structure for the loading of active metals. The prepared composite catalyst contains CaO and Ca(OH)2 structures. The presence of CaO and Ca(OH)2 ensures the catalytic activity of the catalyst and also enhances its stability.
[0008] Preferably, the agricultural and forestry solid waste mentioned in step (1) includes corn stalks, wheat stalks, and waste wood.
[0009] Preferably, the inert atmosphere in step (1) or step (2) includes nitrogen, argon and helium, and the pyrolysis conditions are: pyrolysis treatment at 800℃ for 3 hours.
[0010] Preferably, in step (2), the mass ratio of solid waste pyrolysis char to metallic calcium is 1:0.1-1:0.3, the active material is calcium oxide, and the solid-liquid ratio of the active material to ethanol is 1-6:1000g / mL. More preferably, in step (2), the solid-liquid ratio of the active material to ethanol is 1.5-5.0:1000g / mL.
[0011] Preferably, the solvent in step (2) is ethanol.
[0012] Preferably, the calcination conditions in step (2) are 700℃-900℃ for 30-90 minutes. More preferably, the calcination conditions in step (2) are 800℃ for 60 minutes.
[0013] The second objective of this invention is to provide a pyrolytic carbon-based calcium material catalyst prepared by the aforementioned method, wherein the calcium loading is 10-30 wt%, based on the mass of the support.
[0014] Preferably, the catalyst has a calcium loading of 25 wt%, based on the mass of the support.
[0015] A third objective of this invention is to provide the application of the aforementioned pyrolytic carbon-based calcium material catalyst in the preparation of olefins from waste plastics.
[0016] The fourth objective of this invention is to provide a method for preparing olefins from waste plastics using pyrolytic carbon-based calcium materials, comprising the following steps: thoroughly mixing the pyrolytic carbon-based calcium material catalyst with the waste plastics, subjecting the mixture to a thermal reaction at 400℃-600℃ under an inert atmosphere for 30-60 minutes, collecting the liquid phase product, and calculating the olefin yield after detection.
[0017] Preferably, the thermal reaction conditions are: thermal reaction at 480°C under an inert atmosphere for 60 minutes; the inert atmosphere includes nitrogen, argon and helium.
[0018] The pyrolytic carbon proposed in this invention has a wide range of applications in catalytic materials. As an active metal, metallic calcium has good performance in the catalytic cracking of plastics due to its high activity and low cost. The research and development of pyrolytic carbon-based calcium materials and their application in plastic cracking have certain value.
[0019] Preferably, the mass ratio of the catalyst to waste plastic is 1:5 to 1:1. More preferably, the mass ratio of the catalyst to waste plastic is 3:5 to 4:5.
[0020] The waste plastics proposed in this invention are selected from at least one of polyethylene, polypropylene, and polystyrene.
[0021] Compared with the prior art, the present invention has the following advantages:
[0022] 1. The raw material used in this invention, agricultural solid waste, is widely available and inexpensive. It also makes full use of the excellent properties of agricultural solid waste pyrolysis carbon as a carrier, thus providing a resource utilization method for agricultural solid waste and inventing a new catalyst to improve olefin yield.
[0023] 2. This invention utilizes a novel composite catalyst prepared by combining agricultural solid waste pyrolysis char with metallic active materials. This catalyst is applied to the polypropylene pyrolysis process to increase olefin yield, achieving a pyrolysis oil content of 93.75%, of which the olefin content is 58.87%, and a yield of 0.55 g / g. pp . Attached image description:
[0024] Figure 1 The image shows the SEM image of the catalyst obtained in Example 1.
[0025] Figure 2 The XRD patterns of the catalysts obtained in Examples 1, 6, 7, 8, and 9 are shown. Detailed implementation method:
[0026] The following embodiments are further illustrations of the present invention, but not limitations thereof.
[0027] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention. Unless otherwise specified, the experimental materials and reagents used herein are commercially available products conventional in this art. In the following embodiments, the preferred waste plastic to be treated is polypropylene.
[0028] Example 1
[0029] A method for preparing olefins from waste plastics using pyrolysis of carbon-based calcium materials includes the following steps:
[0030] (1) Take corn stalks as raw material and pyrolyze them at 800℃ in a nitrogen atmosphere for 3 hours to obtain solid waste pyrolysis char.
[0031] (2) Dissolve 0.526g CaO in 100mL ethanol, then weigh 1.5g of the solid waste pyrolysis carbon obtained in step (1) and dissolve it in the CaO solution. Mix the solutions evenly, and evaporate and dry the solutions at a constant temperature of 80℃. The dried solid mixture is then calcined at 800℃ for 60min under a nitrogen atmosphere to obtain the pyrolysis carbon-based calcium material, denoted as 25Ca-TC, in which the metal loading ratio is 25wt%. Characterize the catalyst, such as... Figure 1 As shown, the obtained catalyst surface has a regular porous structure with uniformly distributed surface particles. Figure 2As shown, the supported metal Ca on the catalyst exists in the forms of CaO and Ca(OH)2. The presence of CaO and Ca(OH)2 structures not only ensures the catalytic activity of the catalyst, but also enhances its stability.
[0032] (3) Pyrolytic carbon-based calcium material and waste plastic were thoroughly mixed at a mass ratio of 1:5. The mixture was then thermally reacted at 480℃ for 60 min under a nitrogen atmosphere. The liquid phase product was collected, and the pyrolytic oil content was calculated to be 93.75%, of which the olefin content was 58.87%, and the yield was 0.552 g / g. pp .
[0033] Example 2
[0034] A method for preparing olefins from waste plastics using pyrolysis of carbon-based calcium materials includes the following steps:
[0035] (1) Take corn stalks as raw material and pyrolyze them at 800℃ in a nitrogen atmosphere for 3 hours to obtain solid waste pyrolysis char.
[0036] (2) Dissolve 0.526g CaO in 100mL ethanol, and then weigh 1.5g of solid waste pyrolysis carbon obtained in step (1) and dissolve it in CaO solution and mix evenly. The solution is evaporated and dried at a constant temperature of 80℃. The dried solid mixture is calcined at 800℃ for 60min under a nitrogen atmosphere to obtain pyrolysis carbon-based calcium material, denoted as 25Ca-TC, in which the metal loading ratio is 25wt%.
[0037] (3) Pyrolytic carbon-based calcium material and waste plastic were thoroughly mixed at a mass ratio of 2:5. The mixture was then thermally reacted at 480℃ for 60 min under a nitrogen atmosphere. The liquid phase product was collected, and the pyrolytic oil content was calculated to be 91.55%, of which the olefin content was 56.06%, and the yield was 0.513 g / g. pp .
[0038] Example 3
[0039] A method for preparing olefins from waste plastics using pyrolysis of carbon-based calcium materials includes the following steps:
[0040] (1) Take corn stalks as raw material and pyrolyze them at 800℃ in a nitrogen atmosphere for 3 hours to obtain solid waste pyrolysis char.
[0041] (2) Dissolve 0.526g CaO in 100mL ethanol, and then weigh 1.5g of solid waste pyrolysis carbon obtained in step (1) and dissolve it in CaO solution and mix evenly. The solution is evaporated and dried at a constant temperature of 80℃. The dried solid mixture is calcined at 800℃ for 60min under a nitrogen atmosphere to obtain pyrolysis carbon-based calcium material, denoted as 25Ca-TC, in which the metal loading ratio is 25wt%.
[0042] (3) Pyrolytic carbon-based calcium material and waste plastic were thoroughly mixed at a mass ratio of 3:5. The mixture was then thermally reacted at 480℃ for 60 min under a nitrogen atmosphere. The liquid phase product was collected, and the pyrolytic oil content was calculated to be 90.88%, of which the olefin content was 58.80%, and the yield was 0.534 g / g. pp .
[0043] Example 4
[0044] A method for preparing olefins from waste plastics using pyrolysis of carbon-based calcium materials includes the following steps:
[0045] (1) Take corn stalks as raw material and pyrolyze them at 800℃ in a nitrogen atmosphere for 3 hours to obtain solid waste pyrolysis char.
[0046] (2) Dissolve 0.526g CaO in 100mL ethanol, and then weigh 1.5g of solid waste pyrolysis carbon obtained in step (1) and dissolve it in CaO solution and mix evenly. The solution is evaporated and dried at a constant temperature of 80℃. The dried solid mixture is calcined at 800℃ for 60min under a nitrogen atmosphere to obtain pyrolysis carbon-based calcium material, denoted as 25Ca-TC, in which the metal loading ratio is 25wt%.
[0047] (3) Pyrolytic carbon-based calcium material and waste plastic were thoroughly mixed at a mass ratio of 4:5. The mixture was then thermally reacted at 480℃ for 60 min under a nitrogen atmosphere. The liquid phase product was collected, and the pyrolytic oil content was calculated to be 88.46%, of which the olefin content was 59.71%, and the yield was 0.528 g / g. pp .
[0048] Example 5
[0049] A method for preparing olefins from waste plastics using pyrolysis of carbon-based calcium materials includes the following steps:
[0050] (1) Take corn stalks as raw material and pyrolyze them at 800℃ in a nitrogen atmosphere for 3 hours to obtain solid waste pyrolysis char.
[0051] (2) Dissolve 0.526g CaO in 100mL ethanol, and then weigh 1.5g of solid waste pyrolysis carbon obtained in step (1) and dissolve it in CaO solution and mix evenly. The solution is evaporated and dried at a constant temperature of 80℃. The dried solid mixture is calcined at 800℃ for 60min under a nitrogen atmosphere to obtain pyrolysis carbon-based calcium material, denoted as 25Ca-TC, in which the metal loading ratio is 25wt%.
[0052] (3) Pyrolytic carbon-based calcium material and waste plastic were thoroughly mixed at a mass ratio of 1:1. The mixture was then thermally reacted at 480℃ for 60 min under a nitrogen atmosphere. The liquid phase product was collected, and the pyrolytic oil content was calculated to be 89.01%, of which the olefin content was 58.59%, and the yield was 0.521 g / g. pp .
[0053] Example 6
[0054] A method for preparing olefins from waste plastics using pyrolysis of carbon-based calcium materials includes the following steps:
[0055] (1) Take corn stalks as raw material and pyrolyze them at 800℃ in a nitrogen atmosphere for 3 hours to obtain solid waste pyrolysis char.
[0056] (2) Dissolve 0.211g CaO in 100mL ethanol, then weigh 1.5g of the solid waste pyrolysis carbon obtained in step (1) and dissolve it in the CaO solution. Mix the solutions evenly, and evaporate and dry the solutions at a constant temperature of 80℃. The dried solid mixture is then calcined at 800℃ for 60min under a nitrogen atmosphere to obtain the pyrolysis carbon-based calcium material, denoted as 10Ca-TC, in which the metal loading ratio is 10wt%. Characterize the catalyst, such as... Figure 2 As shown, the supported metal Ca on the catalyst exists in the forms of CaO and Ca(OH)2. The presence of CaO and Ca(OH)2 structures not only ensures the catalytic activity of the catalyst, but also enhances its stability.
[0057] (3) Pyrolytic carbon-based calcium material and waste plastic were thoroughly mixed at a mass ratio of 1:5. The mixture was then thermally reacted at 480℃ for 60 min under a nitrogen atmosphere. The liquid phase product was collected, and the pyrolytic oil content was calculated to be 90.47%, of which the olefin content was 58.17%, and the yield was 0.526 g / g. pp .
[0058] Example 7
[0059] A method for preparing olefins from waste plastics using pyrolysis of carbon-based calcium materials includes the following steps:
[0060] (1) Take corn stalks as raw material and pyrolyze them at 800℃ in a nitrogen atmosphere for 3 hours to obtain solid waste pyrolysis char.
[0061] (2) Dissolve 0.316g CaO in 100mL ethanol, then weigh 1.5g of the solid waste pyrolysis carbon obtained in step (1) and dissolve it in the CaO solution. Mix the mixture thoroughly, and evaporate the solution at a constant temperature of 80℃. The dried solid mixture is then calcined at 800℃ for 60min under a nitrogen atmosphere to obtain the pyrolysis carbon-based calcium material, denoted as 15Ca-TC, where the metal loading ratio is 15wt%. The catalyst is characterized, such as... Figure 2 As shown, the supported metal Ca on the catalyst exists in the forms of CaO and Ca(OH)2. The presence of CaO and Ca(OH)2 structures not only ensures the catalytic activity of the catalyst, but also enhances its stability.
[0062] (3) Pyrolytic carbon-based calcium material and waste plastic were thoroughly mixed at a mass ratio of 1:5. The mixture was then thermally reacted at 480℃ for 60 min under a nitrogen atmosphere. The liquid phase product was collected, and the pyrolytic oil content was calculated to be 90.39%, of which the olefin content was 56.77%, and the yield was 0.513 g / g. pp .
[0063] Example 8
[0064] A method for preparing olefins from waste plastics using pyrolysis of carbon-based calcium materials includes the following steps:
[0065] (1) Take corn stalks as raw material and pyrolyze them at 800℃ in a nitrogen atmosphere for 3 hours to obtain solid waste pyrolysis char.
[0066] (2) Dissolve 0.421 g of CaO in 100 mL of ethanol, then weigh 1.5 g of the solid waste pyrolysis carbon obtained in step (1) and dissolve it in the CaO solution. Mix the solutions evenly, and evaporate and dry the solutions at a constant temperature of 80 °C. The dried solid mixture is then calcined at 800 °C for 60 min under a nitrogen atmosphere to obtain the pyrolysis carbon-based calcium material, denoted as 20Ca-TC, in which the metal loading ratio is 20 wt%. Characterize the catalyst, such as... Figure 2 As shown, the supported metal Ca on the catalyst exists in the forms of CaO and Ca(OH)2. The presence of CaO and Ca(OH)2 structures not only ensures the catalytic activity of the catalyst, but also enhances its stability.
[0067] (3) Pyrolytic carbon-based calcium material and waste plastic were thoroughly mixed at a mass ratio of 1:5. The mixture was then thermally reacted at 480℃ for 60 min under a nitrogen atmosphere. The liquid phase product was collected, and the pyrolytic oil content was calculated to be 91.88%, of which the olefin content was 58.68%, and the yield was 0.539 g / g. pp .
[0068] Example 9
[0069] A method for preparing olefins from waste plastics using pyrolysis of carbon-based calcium materials includes the following steps:
[0070] (1) Take corn stalks as raw material and pyrolyze them at 800℃ in a nitrogen atmosphere for 3 hours to obtain solid waste pyrolysis char.
[0071] (2) Dissolve 0.631g CaO in 100mL ethanol, then weigh 1.5g of the solid waste pyrolysis carbon obtained in step (1) and dissolve it in the CaO solution. Mix the solutions evenly, and evaporate and dry the solutions at a constant temperature of 80℃. The dried solid mixture is then calcined at 800℃ for 60min under a nitrogen atmosphere to obtain the pyrolysis carbon-based calcium material, denoted as 30Ca-TC, in which the metal loading ratio is 30wt%. Characterize the catalyst, such as... Figure 2 As shown, the supported metal Ca on the catalyst exists in the forms of CaO and Ca(OH)2. The presence of CaO and Ca(OH)2 structures not only ensures the catalytic activity of the catalyst, but also enhances its stability.
[0072] (3) Pyrolytic carbon-based calcium material and waste plastic were thoroughly mixed at a mass ratio of 1:5. The mixture was then thermally reacted at 480℃ for 60 min under a nitrogen atmosphere. The liquid phase product was collected, and the pyrolytic oil content was calculated to be 90.07%, of which the olefin content was 57.79%, and the yield was 0.521 g / g. pp .
[0073] Example 10
[0074] A method for preparing olefins from waste plastics using pyrolysis of carbon-based calcium materials includes the following steps:
[0075] (1) Wheat straw was used as raw material and pyrolyzed at 600℃ under an argon atmosphere for 1 hour to obtain solid waste pyrolysis char.
[0076] (2) Dissolve 0.211g CaO in 100mL ethanol, and then weigh 1.5g of solid waste pyrolysis carbon obtained in step (1) and dissolve it in CaO solution and mix evenly. The solution is evaporated and dried at a constant temperature of 80℃. The dried solid mixture is calcined at 700℃ for 30min under an argon atmosphere to obtain pyrolysis carbon-based calcium material, denoted as 10Ca-TC, in which the metal loading ratio is 10wt%.
[0077] (3) Pyrolytic carbon-based calcium material and waste plastic were thoroughly mixed at a mass ratio of 2:5. The mixture was then subjected to a thermal reaction at 400℃ for 30 minutes under an argon atmosphere. The liquid phase product was collected, and the pyrolytic oil content was calculated to be 85.47%, of which the olefin content was 58.17%, and the yield was 0.497 g / g. pp .
[0078] Example 11
[0079] A method for preparing olefins from waste plastics using pyrolysis of carbon-based calcium materials includes the following steps:
[0080] (1) Take waste wood as raw material and pyrolyze it at 700℃ in a helium atmosphere for 2 hours to obtain solid waste pyrolysis char.
[0081] (2) Dissolve 0.316g CaO in 100mL ethanol, and then weigh 1.5g of solid waste pyrolysis carbon obtained in step (1) and dissolve it in CaO solution and mix evenly. The solution is evaporated and dried at a constant temperature of 80℃. The dried solid mixture is calcined at 800℃ for 60min under a helium atmosphere to obtain pyrolysis carbon-based calcium material, denoted as 15Ca-TC, in which the metal loading ratio is 15wt%.
[0082] (3) Pyrolytic carbon-based calcium material and waste plastic were thoroughly mixed at a mass ratio of 3:5. The mixture was then thermally reacted at 500℃ for 40 minutes under a helium atmosphere. The liquid phase product was collected, and the pyrolytic oil content was calculated to be 77.52%, of which the olefin content was 57.48%, and the yield was 0.445 g / g. pp .
[0083] Example 12
[0084] A method for preparing olefins from waste plastics using pyrolysis of carbon-based calcium materials includes the following steps:
[0085] (1) Wheat straw was used as raw material and pyrolyzed at 900℃ under an argon atmosphere for 1 hour to obtain solid waste pyrolysis char.
[0086] (2) Dissolve 0.421g CaO in 100mL ethanol, and then weigh 1.5g of solid waste pyrolysis carbon obtained in step (1) and dissolve it in CaO solution and mix evenly. The solution is evaporated and dried at a constant temperature of 80℃. The dried solid mixture is calcined at 900℃ for 90min under an argon atmosphere to obtain pyrolysis carbon-based calcium material, denoted as 20Ca-TC, in which the metal loading ratio is 20wt%.
[0087] (3) Pyrolytic carbon-based calcium material and waste plastic were thoroughly mixed at a mass ratio of 4:5. The mixture was then thermally reacted at 550℃ for 50 min under an argon atmosphere. The liquid phase product was collected, and the pyrolytic oil content was calculated to be 57.03%, of which the olefin content was 58.05%, and the yield was 0.331 g / g. pp .
[0088] Example 13
[0089] A method for preparing olefins from waste plastics using pyrolysis of carbon-based calcium materials includes the following steps:
[0090] (1) Take corn stalks as raw material and pyrolyze them at 800℃ in a nitrogen atmosphere for 3 hours to obtain solid waste pyrolysis char.
[0091] (2) Dissolve 0.631g CaO in 100mL ethanol, and then weigh 1.5g of solid waste pyrolysis carbon obtained in step (1) and dissolve it in CaO solution and mix evenly. The solution is evaporated and dried at a constant temperature of 80℃. The dried solid mixture is calcined at 800℃ for 60min under a nitrogen atmosphere to obtain pyrolysis carbon-based calcium material, denoted as 30Ca-TC, in which the metal loading ratio is 30wt%.
[0092] (3) Pyrolytic carbon-based calcium material and waste plastic were thoroughly mixed at a mass ratio of 1:1. The mixture was then subjected to a thermal reaction at 600℃ for 60 min under a nitrogen atmosphere. The liquid phase product was collected, and the pyrolytic oil content was calculated to be 42.80%, of which the olefin content was 57.17%, and the yield was 0.245 g / g. pp .
[0093] The above description of the embodiments is only for the purpose of helping to understand the technical solution and core idea of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.
Claims
1. A method for preparing a pyrolytic carbon-based calcium material catalyst, characterized in that, Includes the following steps: (1) Under an inert atmosphere, agricultural and forestry solid waste is pyrolyzed at 600℃-900℃ for 1-3 hours to obtain solid waste pyrolysis char; (2) Using solid waste pyrolysis carbon as a carrier and alkaline earth metal calcium as an active material, the two materials are mixed evenly in a solvent, dried, and the resulting solid material is calcined under an inert atmosphere to obtain the pyrolysis carbon-based calcium material catalyst.
2. The preparation method according to claim 1, characterized in that, The agricultural and forestry solid waste mentioned in step (1) includes corn stalks, wheat stalks and waste wood.
3. The preparation method according to claim 1, characterized in that, The inert atmosphere in step (1) or step (2) includes nitrogen, argon and helium.
4. The preparation method according to claim 1, characterized in that, The mass ratio of solid waste pyrolysis carbon to metallic calcium in step (2) is 1:0.1-1:0.3, the active material is calcium oxide, and the solid-liquid ratio of the active material to ethanol is 1-6:1000g / mL.
5. The preparation method according to claim 1 or 4, characterized in that, The solvent mentioned in step (2) is ethanol.
6. The preparation method according to claim 1 or 4, characterized in that, The calcination conditions described in step (2) are 700℃-900℃ for 30-90 minutes.
7. The pyrolytic carbon-based calcium material catalyst prepared by the preparation method according to any one of claims 1-6, characterized in that, Based on the quality of the carrier, the calcium loading is 10-30 wt%.
8. The application of the pyrolytic carbon-based calcium material catalyst according to claim 7 in the preparation of olefins from waste plastics.
9. A method for preparing olefins from waste plastics using pyrolysis of carbon-based calcium materials, characterized in that, The process includes the following steps: thoroughly mixing the pyrolytic carbon-based calcium material catalyst of claim 7 with waste plastics, subjecting the mixture to a thermal reaction at 400℃-600℃ under an inert atmosphere for 30-60 minutes, collecting the liquid phase product, and calculating the olefin yield after detection.
10. The method according to claim 9, characterized in that, The mass ratio of the catalyst to waste plastic is 1:5 to 1:1.