Method for preparing fuel oil from waste plastics or waste rubber

Abstract

The invention belongs to the technical field of solid waste resource utilization and fuel preparation, and particularly relates to a method for preparing fuel oil from waste plastics or waste rubber. Comprising the following steps: S1, pretreating raw materials; s2, loading materials; s3, mechanochemical conversion: carrying out mechanical ball milling to break and convert molecular chains of the waste plastics or the waste rubber; and S4, product separation: carrying out solid-liquid separation on the ball-milled system, and collecting to obtain the hydrocarbon mixed fuel oil which is in a liquid state or a half-flow state at normal temperature. The method can be used for treating polyolefin and rubber wastes and a mixed system thereof, and is close to an actual complex waste plastic source; additional high temperature and organic solvents are not needed, the process is simplified, and energy consumption and environmental burden are reduced; under the synergistic effect of mechanochemistry and catalytic regulation, a normal-temperature flowable oil product can be stably obtained, and the carbon number and molecular weight distribution are more adaptive to the application scene of fuel oil; and reduction and high-value utilization of the waste plastics are realized, and a supplementary source is provided for fuel oil.

Description

Technical Field

[0001] This invention relates to the field of solid waste resource utilization and fuel preparation technology, specifically a method for preparing fuel oil using waste plastics or waste rubber. Background Technology

[0002] Fuels are crucial energy carriers for modern industry and transportation systems. Liquid fuels, due to their high energy density per unit volume, convenient storage and transportation, and good combustion stability, are widely used in power systems operating continuously for extended periods or under high loads. However, currently, liquid fuels used in transportation and industry primarily originate from petroleum refining processes. Their production is highly dependent on fossil fuels and susceptible to fluctuations in crude oil prices, unstable resource supply, and environmental policies, thus presenting limitations in terms of resource sustainability and environmental friendliness. Developing diverse and easily substitutable liquid fuel resources has become an important focus for the energy and related industrial sectors.

[0003] Meanwhile, polyolefin materials such as polyethylene and polypropylene, as well as rubber materials such as butadiene rubber and ethylene propylene rubber, are widely used in packaging, transportation, construction, and industrial fields, generating a huge amount of waste. These materials are generally predominantly hydrocarbon-chain structures, possessing high theoretical calorific value and fuel conversion potential, making them potentially convertible into fuel oil from a resource perspective. In recent years, mechanochemical techniques have regained attention due to their characteristics of requiring no high temperatures or solvents, and have been applied to the degradation and conversion research of polymer materials. However, existing mechanochemical degradation technologies mostly focus on material crushing, molecular weight reduction, or recycling, and the resulting products are usually low-molecular-weight solids or waxy substances, which are difficult to directly meet the requirements for liquid fuels in terms of physical form and component distribution. Furthermore, without effective catalytic regulation, the degradation efficiency and product composition under mechanochemical action are difficult to stably control, making it difficult to obtain suitable fuel oil.

[0004] Furthermore, research on the synergistic conversion of polyolefins and rubber-based materials remains limited. Existing technologies are mostly designed for single plastic systems, making it difficult to adapt to the complex sources and multiple components of actual waste plastics. Against this backdrop, it is still necessary to develop a new technological solution that can effectively convert waste plastics from complex sources and stably produce fuel oil products, thereby realizing the resource utilization of waste plastics and expanding fuel sources. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of the embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] To address the aforementioned technical problems, according to one aspect of the present invention, the present invention provides the following technical solution: A method for preparing fuel oil using waste plastics or waste rubber includes the following steps: S1: Raw material pretreatment: Select waste polyolefin plastics or waste rubber polymers as raw materials, clean, dry and cut into uniformly sized fragments; S2: Loading: Add the fragments obtained in S1 into the ball mill reactor, add the catalyst and grinding balls, and seal; S3: Mechanochemical conversion: Mechanical ball milling breaks down and converts the molecular chains of waste plastics or waste rubber. S4: Product separation: Solid-liquid separation is performed on the ball-milled system to collect the hydrocarbon mixed fuel oil that is in a liquid or semi-fluid state at room temperature.

[0007] As a preferred embodiment of the method for preparing fuel oil from waste plastics or waste rubber according to the present invention, the raw materials are industrial raw materials, industrial scraps, recycled plastics after use or mixtures thereof, specifically one or more of the following: polyethylene, polypropylene, cis-butadiene rubber and ethylene propylene rubber.

[0008] As a preferred embodiment of the method for preparing fuel oil using waste plastics or waste rubber according to the present invention, the characteristic size of the fragments in S1 is 0.5-10 mm.

[0009] As a preferred embodiment of the method for preparing fuel oil using waste plastics or waste rubber described in this invention, the ball mill jar used in step S2 is made of agate, zirconium oxide, or stainless steel.

[0010] As a preferred embodiment of the method for preparing fuel oil using waste plastics or waste rubber according to the present invention, the catalyst in S2 includes one or more combinations of AlCl3, FeCl3, ZnCl2, TiCl4, BF3, Al2O3, and ZnO.

[0011] As a preferred embodiment of the method for preparing fuel oil using waste plastics or waste rubber according to the present invention, the ratio of catalyst to raw material is 0.01:1-10:1; the mass ratio of grinding media to raw material is 1:1-200:1; and the diameter of grinding media is 1-20 mm.

[0012] As a preferred embodiment of the method for preparing fuel oil using waste plastics or waste rubber according to the present invention, in step S3, the rotation speed of the mechanical ball mill is 100-3000 rpm, and the mechanical ball milling time is 0.25-12 h.

[0013] As a preferred embodiment of the method for preparing fuel oil using waste plastics or waste rubber described in this invention, the oil product in step S4 is in a liquid or semi-fluid state under normal temperature conditions, and the carbon number distribution of the product components is mainly concentrated in the heavy oil range.

[0014] Compared with the prior art, the beneficial effects of the present invention are: (1) Strong adaptability to raw materials: It can process polyolefin and rubber waste and their mixed systems, which are close to the complex sources of actual waste plastics; (2) Green process: No need for external high temperature and organic solvents, the process is simplified, which helps to reduce energy consumption and environmental burden; (3) Product morphology and distribution are controllable: Under the synergistic effect of mechanochemical and catalytic regulation, room temperature flowable oil products can be stably obtained, and the carbon number and molecular weight distribution are more suitable for fuel oil application scenarios. (4) High resource value: It realizes the reduction and high-value utilization of waste plastics and provides a supplementary source for fuel oil. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments. 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 these drawings without creative effort. Wherein: Figure 1 This is a flowchart of a method for preparing fuel oil using waste plastics or waste rubber according to the present invention; Figure 2 This is a photograph of the product oil in Example 1 of a method for preparing fuel oil using waste plastics or waste rubber according to the present invention (the upper layer is water, and the lower layer is the product oil extracted with dichloromethane). Figure 3 This is a gel permeation chromatogram of the product oil in Example 1 of the method for preparing fuel oil using waste plastics or waste rubber of the present invention. Detailed Implementation

[0016] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0017] Secondly, the present invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of the present invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not according to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of the present invention. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0018] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0019] Please see Figure 1 This invention provides a method for preparing fuel oil using waste plastics or waste rubber, comprising the following steps: S1: Raw material pretreatment: Select waste polyolefin plastics or waste rubber polymers as raw materials. The raw materials are industrial raw materials, industrial scraps, recycled plastics after use or their mixtures, specifically one or more of the following: polyethylene, polypropylene, cis-butadiene rubber and ethylene-propylene rubber. Clean, dry and cut into uniformly sized fragments with a characteristic size of 0.5-10 mm. S2: Loading: Add the fragments obtained in S1 into the ball mill reactor. The ball mill jar is made of agate, zirconium oxide, or stainless steel. Add the catalyst and grinding balls and seal the reactor. The catalyst includes AlCl3, FeCl3, ZnCl2, TiCl4, BF3, and one or more combinations of Al2O3 and ZnO. The ratio of catalyst to raw material is 0.01:1-10:1. The mass ratio of grinding media to raw material is 1:1-200:1, and the diameter of the grinding media is 1-20 mm. S3: Mechanochemical conversion: mechanical ball milling, with a rotation speed of 100-3000 rpm and a milling time of 0.25-12 h, to break down and convert the molecular chains of waste plastics or waste rubber; S4: Product separation: Solid-liquid separation is performed on the ball-milled system to collect a hydrocarbon blended fuel oil that is in a liquid or semi-fluid state at room temperature. The carbon number distribution of the product components is mainly concentrated in the heavy oil range.

[0020] Example 1 The catalyst used in this embodiment is AlCl3.

[0021] The method is as follows: Step 1: Weigh 0.408 g of PE powder and 0.56 g of EPM rubber block into an agate ball mill jar; Step 2: Add 1.068 g of AlCl3 powder to the ball mill jar, and add one agate grinding ball each of 3 mm, 5 mm, 8 mm, and 10 mm, and mix well; Step 3: Place the grinding jar in the ball mill and run it at 500 rpm for 2 hours; Step 4: Perform solid-liquid separation on the ball milling product and collect the oil (see [link to product description]). Figure 2 ).

[0022] Component analysis of the above oil products (see [link]). Figure 3 ): In this embodiment, the molecular weight distribution width of the liquid fuel oil obtained in step 4 is Ð=2.238, and the main carbon number range is C8-C9. 27 .

[0023] Example 2 The catalysts used in this embodiment are FeCl3 and AlCl3.

[0024] The method is as follows: Step 1: Weigh 2.04 g of PE plastic bottle fragments, 0.306 g of PP plastic bag fragments, and 0.56 g of EPM rubber block into a stainless steel ball mill jar; Step 2: Add 0.0648 g of FeCl3 powder and 0.1068 g of AlCl3 powder to the ball mill jar, and add 8 stainless steel grinding balls of 3 mm, 5 mm, 8 mm and 10 mm respectively, and mix evenly. Step 3: Place the grinding jar in the ball mill and run it at 1800 rpm for 15 minutes; Step 4: Perform solid-liquid separation on the ball milling product and collect the oil.

[0025] Component analysis of the above oil products: In this embodiment, the molecular weight distribution width of the liquid fuel oil obtained in step 4 is 1.907, and the main carbon number range is C7-C8. 24 .

[0026] Example 3 The catalyst used in this embodiment is ZnO.

[0027] The method is as follows: Step 1: Weigh 2.04 g of PE plastic bag fragments into a zirconia ball mill jar; Step 2: Add 0.065 g of ZnO powder to the ball mill jar, and add 12 zirconium oxide grinding balls of 3 mm, 5 mm, 8 mm and 10 mm respectively, and mix evenly. Step 3: Place the grinding jar in the ball mill and run it at 200 rpm for 10 hours; Step 4: Perform solid-liquid separation on the ball milling product and collect the oil.

[0028] Component analysis of the above oil products: In this embodiment, the molecular weight distribution width of the liquid fuel oil obtained in step 4 is 1.569, and the main carbon number range is C9-C9. 27 .

[0029] Example 4 The catalyst used in this embodiment is ZnCl2.

[0030] Step 1: Weigh 0.204 g of PE plastic bag fragments into a stainless steel ball mill jar; Step 2: Add 10.88 g of ZnCl2 powder to the ball mill jar, and add 12 stainless steel grinding balls of 3 mm, 5 mm, 8 mm and 10 mm respectively, and mix evenly. Step 3: Place the grinding jar in the ball mill and run it at 400 rpm for 4 hours; Step 4: Perform solid-liquid separation on the ball milling product and collect the oil.

[0031] Component analysis of the above oil products: In this embodiment, the molecular weight distribution width of the liquid fuel oil obtained in step 4 is Ð=1.421, and the main carbon number range is C. 10 -C 31 .

[0032] Example 5 The catalyst used in this embodiment is Al2O3.

[0033] Step 1: Weigh 0.204 g of PE plastic bag and 0.306 g of PP disposable lunch box fragments into a stainless steel ball mill jar; Step 2: Add 0.0245 g of Al2O3 powder to the ball mill jar, and add 15 stainless steel grinding balls of 3 mm, 5 mm, 8 mm and 10 mm respectively, and mix evenly. Step 3: Place the grinding jar in the ball mill and run it at 800 rpm for 4 hours; Step 4: Perform solid-liquid separation on the ball milling product and collect the oil.

[0034] Component analysis of the above oil products: In this embodiment, the molecular weight distribution width of the liquid fuel oil obtained in step 4 is 1.473, and the main carbon number range is C7-C8. 34 .

[0035] Example 6 The catalyst used in this embodiment is TiCl4.

[0036] Step 1: Weigh 0.204 g of PE powder and 0.432 g of BR rubber block into an agate ball mill jar; Step 2: Add 15.17 g of TiCl4 powder to the ball mill jar, and add 12 agate grinding balls of 3 mm, 5 mm, 8 mm and 10 mm respectively, and mix evenly; Step 3: Place the grinding jar in the ball mill and run it at 100 rpm for 12 hours; Step 4: Perform solid-liquid separation on the ball milling product and collect the oil.

[0037] Component analysis of the above oil products: In this embodiment, the molecular weight distribution width of the liquid fuel oil obtained in step 4 is Ð=2.273, and the main carbon number range is C6-C6. 29 .

[0038] Example 7 The catalyst used in this embodiment is BF3.

[0039] Step 1: Weigh 6.12 g of PE plastic bottle fragments into a stainless steel ball mill jar; Step 2: Add 1.085 g of BF3 powder to the ball mill jar, and add 9 stainless steel grinding balls of 3 mm, 5 mm, 8 mm and 10 mm respectively, and mix well. Step 3: Place the grinding jar in the ball mill and run it at 3000 rpm for 15 minutes; Step 4: Perform solid-liquid separation on the ball milling product and collect the oil.

[0040] Component analysis of the above oil products: In this embodiment, the molecular weight distribution width of the liquid fuel oil obtained in step 4 is Ð=2.420, and the main carbon number range is C. 11 -C 32 .

[0041] In summary, this invention utilizes waste polyolefin and rubber materials as raw materials, and through a mechanochemical synergistic conversion under specific conditions, achieves the conversion of high-molecular hydrocarbon materials into room-temperature flowable fuel oil. The resulting fuel oil matches the compositional requirements of heavy fuel oil and possesses the potential for application as fuel for marine propulsion systems or as a blending component.

[0042] Although the present invention has been described above with reference to embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, as long as there is no structural conflict, the features in the disclosed embodiments can be combined with each other in any manner. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, the present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for preparing fuel oil using waste plastics or waste rubber, characterized in that, Includes the following steps: S1: Raw material pretreatment: Select waste polyolefin plastics or waste rubber polymers as raw materials, clean, dry and cut into uniformly sized fragments; S2: Loading: Add the fragments obtained in S1 into the ball mill reactor, add the catalyst and grinding balls, and seal; S3: Mechanochemical conversion: Mechanical ball milling breaks down and converts the molecular chains of waste plastics or waste rubber. S4: Product separation: Solid-liquid separation is performed on the ball-milled system to collect the hydrocarbon mixed fuel oil that is in a liquid or semi-fluid state at room temperature.

2. The method for preparing fuel oil using waste plastics or waste rubber according to claim 1, characterized in that, The raw materials are industrial raw materials, industrial scraps, recycled plastics or mixtures thereof, specifically one or more of the following: polyethylene, polypropylene, butadiene rubber and ethylene propylene rubber.

3. The method for preparing fuel oil using waste plastics or waste rubber according to claim 1, characterized in that, The characteristic size of the fragments in S1 is 0.5-10 mm.

4. The method for preparing fuel oil using waste plastics or waste rubber according to claim 1, characterized in that, The grinding jar used in S2 is made of agate, zirconium oxide, or stainless steel.

5. The method for preparing fuel oil using waste plastics or waste rubber according to claim 1, characterized in that, The catalyst in S2 includes AlCl3, FeCl3, ZnCl2, TiCl4, BF3, and one or more combinations of Al2O3 and ZnO.

6. The method for preparing fuel oil using waste plastics or waste rubber according to claim 5, characterized in that, The ratio of catalyst to raw material is 0.01:1-10:1; the mass ratio of grinding media to raw material is 1:1-200:1; and the diameter of grinding media is 1-20 mm.

7. The method for preparing fuel oil using waste plastics or waste rubber according to claim 1, characterized in that, In step S3, the rotation speed of the mechanical ball mill is 100-3000 rpm, and the mechanical ball milling time is 0.25-12 h.

8. The method for preparing fuel oil from waste plastics or waste rubber according to claim 1, characterized in that, The oil products in S4 are in a liquid or semi-fluid state at room temperature, and the carbon number distribution of the product components is mainly concentrated in the heavy oil range.

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