Method for extracting high value-added material from waste oil

Abstract

The invention relates to the technical field of waste grease recycling, in particular to a method for extracting a high value-added material from waste grease, which comprises the following steps: degumming, deacidifying, decolorizing and demetalizing a waste grease raw material to obtain refined grease; carrying out microwave-assisted catalytic cracking on the obtained refined oil; carrying out vacuum distillation on the cracked mixture, and collecting light hydrocarbon fractions, medium fractions and heavy residues in sections; mixing the heavy residues with a solid activator, and carrying out heating carbonization in an inert atmosphere in a tubular furnace; the carbonized product is subjected to acid pickling and water washing to be neutral, and the hierarchical porous carbon material is obtained after drying; according to the method disclosed by the invention, through the pretreatment processes of degumming, deacidification, decoloration and demetallization in sequence, the removal rate of colloid in the waste grease is greatly improved, the content of free fatty acid is reduced, the residual quantity of metal ions is reduced, the poisoning risk of a catalyst is thoroughly eliminated, and the generation amount of subsequent catalytic cracking coke is greatly reduced; therefore, the yield of cracking products is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waste oil regeneration and utilization, and particularly relates to a method for extracting high-value-added materials from waste oil. BACKGROUND

[0002] Resource utilization of waste oil is a key path to solve environmental pollution and realize economic circulation. In particular, extraction of high-value-added materials from waste oil such as catering waste oil and gutter oil has become a research hotspot at present. The existing technology mainly focuses on converting waste oil into biodiesel or low-grade carbon materials. However, biodiesel has the disadvantages of low calorific value and poor oxidation stability. The carbon materials prepared by traditional pyrolysis method are often limited in application value due to single pore structure and insufficient specific surface area. With the surge in demand for new energy devices and high-efficiency adsorption materials, it is of significant industrial importance to develop functional carbon-based materials with high specific surface area, controllable pore size distribution and surface chemical properties. This puts higher requirements on the deep conversion process of waste oil.

[0003] At present, the conventional pretreatment process generally uses single acid treatment or physical filtration, which cannot effectively remove the complex harmful components coexisting in waste oil. Gums (phospholipids, proteins, etc.) and free fatty acids are easy to polymerize and coking in the subsequent high-temperature process, and trace metal ions (such as calcium, sodium, iron, etc.) will irreversibly poison the active sites of the cracking catalyst, leading to uncontrolled cracking reaction path, resulting in excessive coke and reducing the yield and purity of the target product. In addition, the existing carbon material preparation process mainly relies on simple high-temperature carbonization of pyrolysis residues. Although carbon elements can be enriched, it is difficult to precisely construct multi-level pore structures suitable for different application scenarios. High proportion of micropores will limit the diffusion dynamics of ions or molecules inside the material, and insufficient development of mesopores will weaken the accessibility of active sites, resulting in a sharp drop in capacity at high current density (such as more than 30% attenuation of supercapacitor rate performance) in electrochemical energy storage applications, or insufficient dynamic adsorption capacity of less than 50% of the theoretical value in pollutant adsorption.

[0004] Therefore, in view of the problems in the prior art that the metal impurities are not completely removed, leading to a decrease in catalytic efficiency and uncontrollable pore structure of carbon materials, the present application provides a method for extracting high-value-added materials from waste oil. The method completely removes impurities through multi-stage pretreatment to protect the activity of the catalyst, and combines transition metal salts and microwave energy field to regulate the cracking path, so that heavy residues are converted into ideal carbon precursors. Through control of the atmosphere, temperature and activator, the ratio of micropores / mesopores is precisely designed, and finally multi-level pore carbon materials suitable for high-end application scenarios are obtained. SUMMARY

[0005] In order to overcome the problem that the metal impurity removal is not complete in the prior art, leading to the decline of catalytic efficiency and the uncontrollable pore structure of carbon material, the present application provides a method for extracting high value-added material from waste oil.

[0006] The technical scheme of the present application is as follows: a method for extracting high value-added material from waste oil, comprising the following steps: S1, the waste oil raw material is subjected to degumming, deacidification, decolorization and demetallization treatment to obtain refined oil; S2, the refined oil obtained in step S1 is mixed with a transition metal salt catalyst, and microwave-assisted catalytic cracking is carried out under an inert atmosphere, the cracking temperature is 380-450℃, the cracking time is 30-90 minutes, the microwave power density is 1.5-3.0W / g, the catalyst is at least one of acetylacetone salt or nitrate salt of iron, nickel and cobalt, and the addition amount is 0.5-5wt% of the mass of the oil; S3, the mixture after cracking is subjected to vacuum distillation, and light hydrocarbon fraction, medium fraction and heavy residue are collected; S4, the heavy residue obtained in step S3 is mixed with a solid activator, and temperature rising carbonization is carried out in a tube furnace under an inert atmosphere, first rising to 600-750℃ at a rate of 5℃ / min and keeping for 1 hour, then rising to 850-1000℃ at a rate of 2℃ / min and keeping for 2 hours; S5, the product after carbonization is subjected to acid washing and water washing to neutral, and after drying, a hierarchical porous carbon material is obtained.

[0007] As a preferred, the degumming treatment in step S1 uses phosphoric acid or citric acid as a degumming agent; the deacidification treatment uses a sodium hydroxide solution with a concentration of 5% to 10% to carry out the alkali refining method; the decolorization treatment uses activated clay or attapulgite clay as an adsorbent and the addition amount is 3% to 8% of the mass of the waste oil, and is carried out at a temperature of 80-110℃; the demetallization treatment uses ethylenediaminetetraacetic acid or oxalic acid as a complexing agent, and the addition amount is 0.1%-0.5% of the mass of the waste oil.

[0008] As a preferred, the microwave-assisted catalytic cracking step in step S2 is carried out in a batch microwave reactor, the internal pressure of the reactor is maintained in the range of 0.1-0.5MPa, the inert atmosphere is selected from nitrogen or argon, and the gas flow rate is controlled to be 50-200mL / min.

[0009] As a preferred, the catalyst used in the catalytic cracking step in step S2 is a composite catalyst composed of iron acetylacetone and nickel nitrate, and the mass ratio of the two is controlled to be 1:1-1:2, and the total addition amount of the composite catalyst is 2-3.5wt% of the mass of the refined oil.

[0010] As preferred, the vacuum distillation step in the step S3 is carried out under the condition of absolute pressure 0.5-5 kPa, wherein the light hydrocarbon fraction with boiling point lower than 200℃ is separated for preparing green solvent, and the medium fraction with boiling point between 200-350℃ is separated for preparing bio-based lubricant precursor.

[0011] As preferred, the solid activator used in the step S4 is at least one of potassium hydroxide, zinc chloride or phosphoric acid, and when potassium hydroxide is used, the mass ratio thereof to the heavy residue is 1:1-3:1.

[0012] As preferred, when the solid activator is selected as potassium hydroxide, the carbonization activation process needs to be carried out in a carbon dioxide environment, and the carbon dioxide gas flow is controlled at 100-300 mL / min.

[0013] As preferred, the temperature programmed carbonization process in the step S4 is specifically implemented in three stages, the first stage is to heat from room temperature to 300℃ at a rate of 10℃ per minute and keep for 30 minutes, the second stage is to heat from 300℃ to 650℃ at a rate of 5℃ per minute and keep for 60 minutes, and the third stage is to heat from 650℃ to 950℃ at a rate of 2℃ per minute and keep for 120 minutes.

[0014] As preferred, the acid washing treatment in the step S5 uses a hydrochloric acid or sulfuric acid solution with a concentration of 1-3 mol / L, and the stirring is continuously carried out at a temperature range of 60-80℃ for 2-4 hours.

[0015] As preferred, the waste oil and fat in the step S1 includes catering waste oil, gutter oil, vegetable oil refining by-product or animal fat processing waste.

[0016] The beneficial effects of the present application are: 1. The present application greatly improves the removal rate of gum in waste oil and fat by sequentially carrying out the pretreatment processes of degumming, deacidification, decolorization and demetallization, reduces the content of free fatty acid and the residual amount of metal ions, completely eliminates the risk of catalyst poisoning, greatly reduces the amount of coke generated in subsequent catalytic cracking, and thus improves the yield of cracking products.

[0017] 2. The present application uses a transition metal salt composite catalyst to synergize with microwave energy field to intensify cracking, realizes directional chain scission of oil and fat molecules in a low temperature range of 380-450℃, controls the heavy residue yield in the range of 30-40%, and provides an ideal precursor for subsequent carbonization, while the selectivity of light / medium fraction is increased to more than 90%.

[0018] 3. The heavy residue carbonization activation stage of the present application adopts a solid activator regeneration cycle technology, thereby greatly reducing the consumption of potassium hydroxide, and at the same time, the light hydrocarbon fraction is converted into a green solvent, and the medium fraction is converted into a lubricant precursor, thereby realizing the high-value utilization of all components of waste oil, thereby improving the comprehensive economic benefit. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The workflow schematic diagram of the present application is shown. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0021] Please refer to Figure 1 The present application provides an embodiment: a method for extracting high-value-added materials from waste oil, comprising the following steps: S1, the waste oil raw material is subjected to degumming, deacidification, decolorization and demetallization treatment to obtain refined oil; S2, the refined oil obtained in step S1 is mixed with a transition metal salt catalyst, and microwave-assisted catalytic cracking is carried out under an inert atmosphere, the cracking temperature is 380-450℃, the cracking time is 30-90 minutes, the microwave power density is 1.5-3.0W / g, the catalyst is at least one of acetylacetone salt or nitrate salt of iron, nickel and cobalt, and the addition amount is 0.5-5wt% of the mass of the oil; S3, the mixture after cracking is subjected to vacuum distillation, and light hydrocarbon fraction, medium fraction and heavy residue are collected; S4, the heavy residue obtained in step S3 is mixed with a solid activator, and temperature rising carbonization is carried out in a tube furnace under an inert atmosphere, first rising to 600-750℃ at a rate of 5℃ / min and keeping for 1 hour, and then rising to 850-1000℃ at a rate of 2℃ / min and keeping for 2 hours; S5, the product after carbonization is subjected to acid washing and water washing to neutral, and after drying, a multi-level pore carbon material is obtained, the specific surface area of the material is ≥1500m² / g, the micropore pore size distribution is 0.8-1.2nm, and the mesopore pore size distribution is 2-10nm.

[0022] Further, the present application completely removes colloids, acidic substances and metal impurities in waste oil through a four-step pretreatment process, so that the subsequent catalytic cracking reaction system is free from poisoning interference. The present application uses a transition metal salt catalyst to realize directional cracking of oil molecules under the action of microwave energy at 380-450°C, accurately controls the heavy residue yield at 30-40%, and significantly improves the degree of aromatization. By vacuum distillation, light hydrocarbon fractions, medium fractions and heavy residues are separated, ensuring the purity of the carbon precursor. By using a staged heating carbonization combined with an activator to build a multi-level pore structure, a high-value carbon material with a specific surface area of ≥1500m 2 / g, with 0.8-1.2nm micropores and 2-10nm mesopores, is finally obtained, which breaks through the technical bottlenecks of low cracking efficiency, poor residue quality and uncontrollable pore structure of carbon materials in traditional waste oil conversion processes.

[0023] The degumming treatment in the step S1 uses phosphoric acid or citric acid as a degumming agent; the deacidification treatment uses a sodium hydroxide solution with a concentration of 5%-10% for alkali refining; the bleaching treatment uses activated clay or attapulgite clay as an adsorbent and the addition amount is 3% to 8% of the mass of the waste oil, and is carried out at a temperature of 80-110°C; the demetallization treatment uses ethylenediaminetetraacetic acid or oxalic acid as a complexing agent, and the addition amount is 0.1%-0.5% of the mass of the waste oil.

[0024] Further, the degumming treatment is described in detail as follows: The waste oil is preheated to 55-65°C, 0.1-0.5wt% of 85% phosphoric acid or 50% citric acid solution is added, and the dispersion reaction is carried out at 500-800rpm high-speed shearing for 20-40 minutes. Phosphoric acid / citric acid is used to destroy the colloidal hydration film and promote the conversion of non-hydrated phospholipids (NHP) to calcium-sensitive phospholipids. Then 2-3% of 60-70°C hot water is added for hydration to form colloidal particle flocculation bodies rich in phospholipids. Finally, centrifugal separation is used to achieve a gum removal rate of ≥90%.

[0025] Further, the degumming treatment can also be carried out in the following way: The degumming treatment first heats the waste oil to 80-110°C, then adds 3-8wt% of activated clay or attapulgite clay as an adsorbent and continuously stirs for 30-60 minutes. The high specific surface area and surface acidic sites of the layered silicate structure of the adsorbent are used to capture colloidal impurities such as phospholipids and proteins, promote the coagulation and precipitation of colloids through polar interaction, and achieve a colloidal removal rate of ≥95%.

[0026] Further, the deacidification treatment is described in detail as follows: The deacidification treatment directly adds a sodium hydroxide solution with a concentration of 5%-10% in the system after degumming, controls the alkali addition amount to be 1.05-1.2 times of the theoretical neutralization value, and stirs and reacts at 65-75°C for 20-40 minutes, so that the free fatty acid is saponified into water-soluble soapstock, and the free fatty acid content is reduced to below 0.1% after centrifugal separation.

[0027] Further, the decolorization treatment is described in detail as follows: The decolorization treatment adds 3-8wt% of activated clay or attapulgite clay in the deacidified and purified oil, stirs and adsorbs under vacuum at 80-110°C for 40-80 minutes, uses high temperature to strengthen the diffusion rate of pigment molecules (such as chlorophyll and carotenoids) into the pore channels of the adsorbent, so that the oil colority is reduced from an initial red value of ≥15.0 to ≤2.0.

[0028] Further, the demetallization treatment is described in detail as follows: The demetallization treatment finally adds 0.1-0.5wt% of ethylenediaminetetraacetic acid or oxalic acid as a complexing agent in the deacidified and purified oil, stirs gently at 60-80°C for 1-2 hours, forms a water-soluble complex through the strong chelation of the carboxyl group of the complexing agent with calcium, magnesium, iron and other metal ions, and after water washing and separation, the residual amount of metal ions is ≤5ppm, thereby completely eliminating the risk of metal impurities poisoning the active sites of the catalyst in the subsequent catalytic cracking process.

[0029] The microwave-assisted catalytic cracking step in the step S2 is carried out in a batch microwave reactor, the internal pressure of the reactor is maintained in the range of 0.1-0.5MPa, the inert atmosphere is selected to be nitrogen or argon, and the gas flow rate is controlled to be 50-200mL / min.

[0030] Further, the microwave-assisted catalytic cracking step first mixes the refined oil with the transition metal salt catalyst, then places it in a quartz reaction kettle, seals the reactor and replaces the air with nitrogen or argon three times, then maintains the inert gas flow rate at 50-200mL / min to form a dynamic protective atmosphere, adjusts the internal pressure of the reactor to the range of 0.1-0.5MPa before starting microwave irradiation, controls the pressure through a pressure sensor and a pressure relief valve to ensure that the pressure fluctuation in the system during cracking is ≤±5%, and after the microwave irradiation is turned on, the reaction material is cracked at 380-450°C, so that the oil molecules are uniformly heated up in 30-90 minutes, and at the same time, the transition metal ions induce the formation of local hot spots in the microwave field, which catalyzes the selective cleavage of C-C bonds to generate short-chain hydrocarbons.

[0031] The catalyst used in the catalytic cracking step in the step S2 is a composite catalyst composed of iron acetylacetate and nickel nitrate, and the mass ratio of the two is controlled to be 1:1-1:2, and the total addition amount of the composite catalyst is 2-3.5wt% of the mass of the refined oil.

[0032] Further, the present application adopts a composite catalyst composed of acetylacetone iron and nickel nitrate in a mass ratio of 1:1-1:2, under the condition that the total addition amount is 2-3.5wt% of the mass of refined oil, the cracking efficiency is significantly improved through the synergistic effect of iron-nickel bimetallic active centers, wherein the iron ion acts as a strong Lewis acid site to catalyze the β-scission of triglyceride to generate fatty acids, the nickel ion is in-situ reduced to metal nickel nanoparticles at the cracking temperature to catalyze the decarboxylation / decarbonylation of fatty acids to generate linear olefins, the electron transfer at the bimetallic interface reduces the C-C bond cracking activation energy from 180kJ / mol of single component to 140-150kJ / mol, and the cracking reaction temperature window is widened to 380-430℃.

[0033] The vacuum distillation step in the step S3 is carried out under the condition of absolute pressure of 0.5-5kPa, wherein the light hydrocarbon fraction with boiling point lower than 200℃ is separated for preparing green solvent, and the medium fraction with boiling point between 200-350℃ is separated for preparing bio-based lubricant precursor.

[0034] The solid activator used in the step S4 is at least one of potassium hydroxide, zinc chloride or phosphoric acid, and when potassium hydroxide is used, the mass ratio thereof to heavy residue is 1:1-3:1.

[0035] When the solid activator is potassium hydroxide, the carbonization activation process needs to be carried out in a carbon dioxide environment, and the carbon dioxide gas flow is controlled at 100-300mL / min.

[0036] Further, when potassium hydroxide is used as the activator and the mass ratio thereof to heavy residue is controlled at 1:1-3:1, the potassium hydroxide is molten and penetrated into the interior of the carbon skeleton at a carbonization temperature of 600-1000℃, and through the redox reaction (6KOH + 2C→ 2K + 3H2 + 2K2CO3), the carbon atoms are selectively etched to build a microporous structure, the network mainly composed of narrow micropores with a size of 0.8-1.2nm is formed when the mass ratio is 1:1, and the pore widening effect is enhanced to increase the mesopore proportion to 40-50% when the mass ratio is increased to 3:1; if zinc chloride is used as the activator (mass ratio 1:1-3:1), the zinc chloride is molten and embedded between the carbon layers at a lower temperature (300℃), which inhibits the generation of tar and promotes the crosslinking reaction to form layered carbon dominated by mesopores with a size of 2-5nm; if phosphoric acid is used for activation (mass ratio 1:1-3:1), the strong dehydrating property of polyphosphoric acid generated by the polymerization of phosphoric acid promotes the aromatization and condensation of carbon precursors to build hierarchical pores coexisting with wide mesopores with a size of 2-10nm and micropores.

[0037] The programmed temperature carbonization process in step S4 is specifically implemented in three stages, the first stage is to heat from room temperature to 300°C at a rate of 10°C per minute and keep for 30 minutes, the second stage is to heat from 300°C to 650°C at a rate of 5°C per minute and keep for 60 minutes, and the third stage is to heat from 650°C to 950°C at a rate of 2°C per minute and keep for 120 minutes.

[0038] The pickling treatment in step S5 adopts a hydrochloric acid or sulfuric acid solution with a concentration of 1-3 mol / L, and the stirring is continuously carried out at a temperature range of 60-80°C for 2-4 hours.

[0039] The application provides an embodiment of application of the multi-level pore carbon material to a supercapacitor electrode. Material preparation: Take catering waste oil (acid value 12.5 mgKOH / g, calcium content 185 ppm), add 0.3% of the oil mass of 85% phosphoric acid solution, shear at 700 rpm at 65°C for 30 minutes, the removal rate of gum after hydration centrifugation is 92%, then add 5% NaOH solution, react at 70°C for 30 minutes, the free fatty acid is reduced to 0.08%, then add 6% activated clay, stir at 100°C under vacuum (8 kPa) for 50 minutes, the color red value is reduced from 16.5 to 1.8, finally add 0.3% ethylenediaminetetraacetic acid, stir at 70°C for 1.5 hours, and the residual calcium content is 4.2 ppm after water washing, to obtain refined oil.

[0040] Mix the refined oil with 2.5% acetylacetone iron-nitric acid nickel (1:1) composite catalyst, crack in a batch microwave reactor at a nitrogen flow rate of 100 mL / min, a pressure of 0.3 MPa, and a microwave power density of 2.0 W / g, at an ambient temperature of 400°C for 60 minutes, and separate the cracking products by vacuum distillation: the light fraction with a boiling point of <200°C accounts for 38%, the medium fraction with a boiling point of 200-350°C accounts for 32%, and the heavy residue with a boiling point of >350°C has a yield of 30%.

[0041] Mix the heavy residue with KOH (mass ratio 2:1), and perform three-stage programmed temperature heating in a tube furnace: 10°C / min to 300°C for 30 min, 5°C / min to 650°C for 60 min, and 2°C / min to 950°C for 120 min; and the carbonization product is pickled with 2M H2SO4 and washed with water until pH=7.0.

[0042] Application of the obtained material: The specific surface area of the obtained carbon material is 1820 m 2The micropore ratio of 0.8-1.2 nm is 68%, the mesopore ratio of 2-5 nm is 29%, as an electrode of super capacitor: active material / acetylene black / PTFE are mixed at 80:15:5 to coat a nickel net, the specific capacitance is 283 F / g at 1 A / g in 6M KOH electrolyte, and the retention rate is 88% at 20 A / g.

[0043] The above merely describes the preferred embodiments of the present application, and is not intended to limit the present application in other forms. Any person skilled in the art can modify or change the above disclosed technical content to equivalent embodiments applied to other fields, but any simple modification, equivalent change and modification made to the above embodiments without departing from the technical solution content of the present application, and in accordance with the technical essence of the present application, still belong to the protection scope of the technical solution of the present application.

Claims

1. A method for extracting high-value-added materials from waste oil, characterized in that, It includes the following steps: S1, the waste oil raw material is degummed, deacidified, decolorized and demetallized to obtain refined oil; S2, the refined oil obtained in step S1 is mixed with a transition metal salt catalyst and subjected to microwave-assisted catalytic pyrolysis under an inert atmosphere. The pyrolysis temperature is 380-450℃, the pyrolysis time is 30-90 minutes, and the microwave power density is 1.5-3.0 W / g. The catalyst is at least one of iron, nickel, cobalt acetylacetone salts or nitrates, and the amount added is 0.5-5 wt% of the oil mass. S3, the pyrolysis mixture is vacuum distilled to collect light hydrocarbon fraction, medium fraction and heavy residue in stages; S4. The heavy residue obtained in step S3 is mixed with a solid activator and heated and carbonized in an inert atmosphere in a tube furnace. First, the temperature is increased to 600-750℃ at a rate of 5℃ / min and held for 1 hour, and then increased to 850-1000℃ at a rate of 2℃ / min and held for 2 hours. S5, the carbonized product is acid-washed and water-washed until neutral, and then dried to obtain a hierarchical porous carbon material.

2. The method for extracting high-value-added materials from waste oil according to claim 1, characterized in that: In step S1, the degumming treatment uses phosphoric acid or citric acid as the degumming agent; the deacidification treatment uses an alkali refining method with a sodium hydroxide solution of 5% to 10% concentration; the decolorization treatment uses activated clay or attapulgite clay as the adsorbent, with an addition amount of 3% to 8% of the waste oil mass, and is carried out at a temperature of 80-110℃; the demetallization treatment uses ethylenediaminetetraacetic acid or oxalic acid as the complexing agent, with an addition amount of 0.1% to 0.5% of the waste oil mass.

3. The method for extracting high-value-added materials from waste oil according to claim 1, characterized in that: The microwave-assisted catalytic cracking step in step S2 is carried out in an intermittent microwave reactor. The internal pressure of the reactor is maintained in the range of 0.1-0.5 MPa, and the inert atmosphere is selected as nitrogen or argon, with the gas flow rate controlled at 50-200 mL / min.

4. The method for extracting high-value-added materials from waste oil according to claim 1, characterized in that: The catalyst used in the catalytic cracking step in step S2 is a composite catalyst composed of iron acetylacetone and nickel nitrate, with the mass ratio of the two controlled at 1:1-1:2, and the total amount of composite catalyst added is 2-3.5 wt% of the mass of refined oil.

5. The method for extracting high-value-added materials from waste oil according to claim 1, characterized in that: The vacuum distillation step in step S3 is carried out under an absolute pressure of 0.5-5 kPa, wherein light hydrocarbon fractions with boiling points below 200°C are separated for the preparation of green solvents, and medium fractions with boiling points between 200-350°C are separated for the preparation of bio-based lubricant precursors.

6. The method for extracting high-value-added materials from waste oil according to claim 1, characterized in that: The solid activator used in step S4 is at least one of potassium hydroxide, zinc chloride, or phosphoric acid. When potassium hydroxide is used, its mass ratio with the heavy residue is 1:1 to 3:

1.

7. A method for extracting high-value-added materials from waste oil according to claim 6, characterized in that: When potassium hydroxide is chosen as the solid activator, the carbonization activation process needs to be carried out in a carbon dioxide environment, and the carbon dioxide gas flow rate is controlled at 100-300 mL / min.

8. The method for extracting high-value-added materials from waste oil according to claim 1, characterized in that: The programmed heating carbonization process in step S4 is specifically implemented in three stages: the first stage is to heat from room temperature to 300°C at a rate of 10°C per minute and hold for 30 minutes; the second stage is to heat from 300°C to 650°C at a rate of 5°C per minute and hold for 60 minutes; and the third stage is to heat from 650°C to 950°C at a rate of 2°C per minute and hold for 120 minutes.

9. A method for extracting high-value-added materials from waste oil according to claim 1, characterized in that: The pickling process in step S5 uses a hydrochloric acid or sulfuric acid solution with a concentration of 1-3 mol / L, and is continuously stirred for 2-4 hours within a temperature range of 60-80℃.

10. A method for extracting high-value-added materials from waste oil according to claim 1, characterized in that: The waste oil in step S1 includes waste cooking oil, gutter oil, vegetable oil refining by-products, or animal fat processing waste.

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