A method of treating chlorine-containing waste plastic pyrolysis oil

Abstract

The present disclosure relates to a method for treating waste plastic pyrolysis oil containing chlorine, comprising the following steps: S1, contacting waste plastic pyrolysis oil, catalyst and hydrogen, and carrying out a mild catalytic hydrogenation thermal conversion reaction in a reactor to obtain a thermal conversion reaction product; S2, feeding the thermal conversion reaction product into a thermal high separation device for gas-liquid separation treatment to obtain a gas phase product and a liquid phase product; S3, carrying out alkali washing treatment on the gas phase product to obtain a purified gas phase; S4, carrying out water injection treatment on the liquid phase product and then carrying out oil-water separation treatment to obtain a dechlorinated oil phase product. The present disclosure can remove most of the chlorine in the waste plastic pyrolysis oil, while significantly reducing the content of unsaturated hydrocarbons in the waste plastic pyrolysis oil, and the stability of the pretreated product is higher, providing high-quality raw materials for subsequent processing. The process flow of the present disclosure is simple, and the online addition of catalyst can realize long-period operation of the device.

Description

Technical Field

[0001] This disclosure relates to the field of waste plastic utilization, and more specifically, to a method for treating chlorine-containing waste plastic pyrolysis oil. Background Technology

[0002] The growing demand for sustainable products, coupled with regulatory and investor pressure, has prompted chemical manufacturers around the world to utilize various technologies to reuse waste plastics.

[0003] Chemical recycling of waste plastics involves using technologies such as thermal or chemical decomposition to pyrolyze and recombine plastic waste at the molecular level, transforming its components into raw materials such as plastic oils. This method has significant advantages in processing mixed plastic waste, especially low-value waste plastics. Chemical recycling pyrolyzes waste plastics into plastic raw materials, which can then be further processed into new products and plastics of the same quality as those produced from virgin materials, truly achieving the circular recycling and sustainable development of waste plastics.

[0004] Waste plastic pyrolysis oil is a relatively low-quality oil product, characterized by its high chlorine content, which has a significant impact on the safety, economy, and environmental protection of subsequent processing and utilization of pyrolysis oil.

[0005] Industrial dechlorination technologies mainly include adsorption dechlorination, catalytic hydrodechlorination, electrochemical dechlorination, and biological dechlorination. Among these, electrochemical and biological dechlorination are less studied, less mature, and have narrower applications. Industrially, adsorption dechlorination, including both physical and chemical adsorption, is more commonly used. However, the chlorine capacity of adsorbents is generally small, limiting their application to feedstocks with low chlorine content. Waste plastic pyrolysis oil, on the other hand, has a high chlorine content and contains many heteroatoms that can competitively adsorb. Direct adsorption can easily lead to rapid saturation of the adsorbent, reducing dechlorination efficiency. Catalytic hydrodechlorination primarily uses fixed-bed hydroreactors to refine waste plastic pyrolysis oil. The process requires the use of hydroprotective agents or the development of special catalyst gradation systems to mitigate catalyst deactivation and extend the unit's operating cycle. Summary of the Invention

[0006] The purpose of this disclosure is to provide a method for treating chlorine-containing waste plastic pyrolysis oil, which can remove most of the chlorine from the waste plastic pyrolysis oil, while significantly reducing the content of unsaturated hydrocarbons in the waste plastic pyrolysis oil. The pretreated product has higher stability and provides high-quality raw materials for subsequent processing. The process of this disclosure is simple and the catalyst can be added online without periodic constraints.

[0007] To achieve the above objectives, this disclosure provides a method for treating chlorine-containing waste plastic pyrolysis oil, comprising the following steps:

[0008] S1. Contact waste plastic pyrolysis oil, catalyst and hydrogen in a reactor to carry out a mild catalytic hydrogen thermal conversion reaction to obtain thermal conversion reaction products.

[0009] S2. The thermal conversion reaction products are fed into a thermal high-efficiency separator for gas-liquid separation to obtain gaseous and liquid products.

[0010] S3. The gaseous product is subjected to alkaline washing to obtain a purified gaseous phase.

[0011] S4. The liquid phase product is subjected to water injection treatment and then oil-water separation treatment to obtain dechlorinated oil phase product.

[0012] Optionally, in step S1, the catalyst is selected from one or more of the first oil-soluble catalysts;

[0013] Preferably, the first oil-soluble catalyst is selected from compounds containing one or more elements selected from Group VB, Group VIB and Group VIII metals; more preferably, it is selected from organic compounds containing one or more elements selected from Group VB, Group VIB and Group VIII metals; more preferably, it is selected from one or more of molybdenum-containing organic compounds, tungsten-containing organic compounds, nickel-containing organic compounds, cobalt-containing organic compounds, iron-containing organic compounds, vanadium-containing organic compounds and chromium-containing organic compounds.

[0014] More preferably, the first oil-soluble catalyst is selected from one or more of molybdenum carbonyl, iron organic carboxylate, molybdenum naphthenate, iron naphthenate, molybdenum ethylhexanoate, nickel ethylhexanoate, and molybdenum dialkyldithiocarbamate.

[0015] Optionally, in step S1, the catalyst is selected from one or more of the second oil-soluble catalysts;

[0016] Preferably, the second oil-soluble catalyst comprises a complex formed by a metal central atom or metal central ion and a first organic ligand bonded together by a coordination bond; wherein the metal elements in the metal central atom and the metal central ion are each independently selected from one or more of Group VB, Group VIB, Group VIII, and Group IB metals; the first organic ligand comprises a hydrocarbon moiety and a coordinating group moiety, wherein the coordinating group is a -C(=O)-O group and forms a coordination bond with the metal central atom or metal central ion through an oxygen atom;

[0017] Optionally, R(COO) x R represents the first organic ligand, and R represents the hydrocarbon group in the first organic ligand.

[0018] Optionally, the second oil-soluble catalyst has the composition shown in formula (I):

[0019] MO a [R(COO) x ] b (I),

[0020] Where M represents the metal, and R(COO) x Let R represent the first organic ligand, R represent the hydrocarbon group in the first organic ligand, COO represent the coordinating group in the first organic ligand, x represent the number of coordinating groups in the first organic ligand, a represent the molar ratio of non-coordinated oxygen atoms bonded to metal M to metal M, and b represent the molar ratio of the first organic ligand to metal M, where:

[0021] R is selected from C3 to C19 hydrocarbon groups, preferably from C5 to C11 normal alkyl, C5 to C11 isoalkyl, C5 to C12 cycloalkyl or C6 to C12 aryl;

[0022] x is 1, 2 or 3, preferably 1 or 2;

[0023] a can be any value in the range of 0 to 3, preferably any value in the range of 1 to 3; and

[0024] b is any value in the range of 1 to 6, preferably any value in the range of 2 to 5;

[0025] Preferably, M includes M 1 and M 2 M 1 and M 2 They are different from each other.

[0026] Optionally, the metallic element is selected from one or more of V, Cr, Mo, W, Fe, Co, Ru, Ni, Cu and Pd, preferably from one or more of Mo, Ni, W, Fe, V and Co;

[0027] The first organic ligand is selected from organic carboxylic acids of C4 to C20, preferably one or more selected from normal or isomeric alkyl carboxylic acids of C4 to C20, cycloalkanic carboxylic acids containing saturated carbocyclic rings of C6 to C20, and aromatic carboxylic acids containing aromatic rings of C7 to C20. More preferably, it is selected from one or more selected from normal or isomeric alkyl carboxylic acids of C6 to C12, cycloalkanic carboxylic acids containing saturated carbocyclic rings of C6 to C13, and aromatic carboxylic acids containing aromatic rings of C7 to C13. Further preferably, it is selected from one or more selected from succinic acid, hexanoic acid, adipic acid, heptanoic acid, octanoic acid, nonanoic acid, ethylhexanoic acid, oleic acid, petroleum ether, salicylic acid, benzoic acid, and phenylacetic acid.

[0028] Optionally, based on the total weight of the second oil-soluble catalyst, the metal content of the catalyst, in metallic form, is 5-35% by weight, preferably 8-30% by weight, more preferably 10-25% by weight, and particularly preferably 10-20% by weight;

[0029] Optionally, the molar ratio of the metal element to the first organic ligand is 1:(0.5 to 3.5), preferably 1:(1.5 to 2.5).

[0030] Optionally, the second oil-soluble catalyst is used in the form of a catalyst composition comprising the second oil-soluble catalyst and at least one second organic ligand compound and / or organic solvent, wherein,

[0031] The second organic ligand compound is selected from C4-C20 organic carboxylic acids, preferably from one or more of C4-C20 normal or isomeric alkyl carboxylic acids, C6-C20 cycloalkane carboxylic acids containing saturated carbocyclic rings, and C7-C20 aromatic carboxylic acids containing aromatic rings, more preferably from one or more of C6-C12 normal or isomeric alkyl carboxylic acids, C6-C13 cycloalkane carboxylic acids containing saturated carbocyclic rings, and C7-C13 aromatic carboxylic acids containing aromatic rings, and even more preferably from one or more of succinic acid, hexanoic acid, adipic acid, heptanoic acid, octanoic acid, nonanoic acid, ethylhexanoic acid, oleic acid, petroleum ether, salicylic acid, benzoic acid, and phenylacetic acid;

[0032] Optionally, the organic solvent is selected from one or more of aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, alcohol solvents, ether solvents, ester solvents and ketone solvents, and preferably from one or more of toluene, gasoline, ethanol and diesel.

[0033] Optionally, the catalyst composition comprises at least one of the second organic ligand compounds;

[0034] Preferably, based on the total weight of the catalyst composition, the content of the second oil-soluble catalyst is 50-95% by weight, preferably 80-95% by weight; and the total content of the second organic ligand compound and the organic solvent is 5-50% by weight, preferably 5-20% by weight.

[0035] Optionally, in step S1, the waste plastic pyrolysis oil is obtained by subjecting the waste plastic raw material to one or more of the following methods: thermal cracking, thermal pyrolysis, catalytic cracking, and catalytic pyrolysis.

[0036] Optionally, in step S1, the chlorine content in the waste plastic pyrolysis oil is below 10000 μg / g, preferably 100 to 5000 μg / g; optionally, the final boiling point of the waste plastic pyrolysis oil is below 700℃.

[0037] Optionally, step S1 includes:

[0038] The waste plastic pyrolysis oil and catalyst are mixed and then subjected to a first preheating treatment to obtain a preheated raw material mixture; preferably, the temperature of the preheated raw material mixture is 100-350℃, more preferably 200-300℃;

[0039] Hydrogen gas is subjected to a second preheating treatment to obtain preheated hydrogen gas; preferably, the temperature of the preheated hydrogen gas is 150-450°C, more preferably 200-400°C;

[0040] The preheated raw material mixture and preheated hydrogen are introduced into the reactor through the bottom of the reactor; optionally, the reactor is a slurry bed reactor;

[0041] Optionally, the mixing process employs one or more of a mechanical stirring device, a static mixing device, and an ultrasonic dispersing device.

[0042] Optionally, in step S1, the conditions for the moderate catalytic hydrothermal conversion reaction include:

[0043] The reaction temperature is 150–450℃, preferably 200–400℃, and more preferably 200–350℃; the hydrogen partial pressure is 0.1–15 MPa, preferably 2–10 MPa; and the liquid hourly space velocity is 0.05–10 h⁻¹. -1 Preferably 0.1 to 5 hours -1 More preferably, it is 0.1–0.2 h. -1 The catalyst concentration is 0.1–20000 μg / g, preferably 500–15000 μg / g; the hydrogen-to-oil volume ratio is 0.1–1000 Nm. 3 / m 3 Preferably, it is 50–500 Nm 3 / m 3 .

[0044] Optionally, in step S2, the operating conditions of the thermal high-resolution apparatus include:

[0045] The temperature is 100–400℃ and the pressure is 0.1–15 MPa; preferably, the temperature is 150–350℃ and the pressure is 2–10 MPa.

[0046] Optionally, in step S3, the conditions for the alkaline washing treatment include: the pH of the alkaline solution is above 10.

[0047] Optionally, the method further includes:

[0048] At least a portion of the purified gas obtained in step S3 is returned to step S1 as recycled hydrogen for continued use;

[0049] Optionally, the volume ratio of recycled hydrogen to fresh hydrogen is 0 to 1.2:1, preferably 0.5 to 1:1;

[0050] Optionally, the hydrogen purity in the purified gas obtained in step S3 is above 85% by volume.

[0051] Optionally, in step S4, the conditions for the water injection treatment include:

[0052] The temperature of the liquid product at the water injection point is above 150°C, preferably 150-250°C; the temperature of the water is 20-50°C; and the mass ratio of the water injection volume to the liquid product is 0.5-10:1, preferably 1-5:1.

[0053] Optionally, the water used for water injection treatment is selected from one or more of demineralized water, deoxygenated water, and condensate.

[0054] Through the above technical solution, this disclosure provides a method for treating chlorine-containing waste plastic pyrolysis oil. This method can remove most of the chlorine from the waste plastic pyrolysis oil, and finally obtain pyrolysis oil with low chlorine content. At the same time, it significantly reduces the unsaturated hydrocarbon content in the waste plastic pyrolysis oil. The treated oil phase product has higher stability and provides high-quality raw materials for subsequent processing. The process of this disclosure is simple and the online addition of catalyst can realize long-term operation of the equipment.

[0055] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0056] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0057] Figure 1 This is a process flow diagram of the method for treating chlorine-containing waste plastic pyrolysis oil provided in this disclosure.

[0058] Figure Labels

[0059] I-Slurry Bed Reactor II-High-Efficiency Separation Unit III-Gas Cooler

[0060] IV-Alkali Washing Tower V-Oil-Water Separator 1-Plastic Pyrolysis Oil

[0061] 2-Catalyst 3-Hydrogen 4-Pipeline

[0062] 5-Pipeline 6-Pipeline 7-Gas Products

[0063] 8-Pipeline 9-Water 10-Wastewater

[0064] 11-Low-chlorine products Detailed Implementation

[0065] The following provides a detailed description of specific embodiments of this disclosure. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit this disclosure.

[0066] This disclosure provides a method for treating chlorine-containing waste plastic pyrolysis oil, comprising the following steps:

[0067] S1. Contact waste plastic pyrolysis oil, catalyst and hydrogen in a reactor to carry out a mild catalytic hydrogen thermal conversion reaction to obtain thermal conversion reaction products.

[0068] S2. The thermal conversion reaction products are fed into a thermal high-efficiency separator for gas-liquid separation to obtain gaseous and liquid products.

[0069] S3. The gaseous product is subjected to alkaline washing to remove acidic gases such as hydrogen chloride, and a purified gaseous phase is obtained.

[0070] S4. The liquid product is subjected to water injection treatment and then oil-water separation treatment to remove inorganic chlorides from the product, thereby obtaining a dechlorinated oil phase product.

[0071] This disclosure provides a method for treating chlorine-containing waste plastic pyrolysis oil. This method can remove most of the chlorine from the waste plastic pyrolysis oil, ultimately obtaining pyrolysis oil with low chlorine content. At the same time, it significantly reduces the unsaturated hydrocarbon content in the waste plastic pyrolysis oil, and the treated oil phase product has higher stability, providing high-quality raw materials for subsequent processing. The process of this disclosure is simple, and the online addition of catalyst can realize long-term operation of the equipment.

[0072] In one embodiment, the catalyst is selected from one or more of a first oil-soluble homogeneous catalyst;

[0073] Preferably, the first oil-soluble homogeneous catalyst is selected from compounds containing one or more elements selected from Group VB, Group VIB and Group VIII metals; more preferably, it is selected from organic compounds containing one or more elements selected from Group VB, Group VIB and Group VIII metals; more preferably, it is selected from one or more of molybdenum-containing organic compounds, tungsten-containing organic compounds, nickel-containing organic compounds, cobalt-containing organic compounds, iron-containing organic compounds, vanadium-containing organic compounds and chromium-containing organic compounds.

[0074] More preferably, the first oil-soluble homogeneous catalyst is selected from one or more of molybdenum carbonyl, iron organic carboxylate, molybdenum naphthenate, iron naphthenate, molybdenum ethylhexanoate, nickel ethylhexanoate, and molybdenum dialkyldithiocarbamate. The first oil-soluble homogeneous catalyst can be obtained commercially or prepared by known methods.

[0075] In another embodiment, in step S1, the catalyst is selected from one or more of the second oil-soluble catalysts;

[0076] Optionally, the second oil-soluble catalyst comprises a complex formed by a metal central atom or metal central ion and a first organic ligand bonded together by coordination bonds; wherein the metal elements in the metal central atom and metal central ion are each independently selected from one or more of Group VB, Group VIB, Group VIII, and Group IB metals with hydrogenation properties; the first organic ligand comprises a hydrocarbon moiety and a coordinating group moiety, wherein the coordinating group is a -C(=O)-O group and forms a coordination bond with the metal central atom or metal central ion through an oxygen atom;

[0077] Optionally, R(COO) x R represents the first organic ligand, and R represents the hydrocarbon group in the first organic ligand.

[0078] In a preferred embodiment, the molar ratio of the metal element to the first organic ligand is 1:(0.5 to 3.5), preferably 1:(1.5 to 2.5).

[0079] In one specific embodiment, the second oil-soluble catalyst has the composition shown in formula (I):

[0080] MO a [R(COO) x ] b (I),

[0081] Where M represents the metal, and R(COO) x Let R represent the first organic ligand, R represent the hydrocarbon group in the first organic ligand, COO represent the coordinating group in the first organic ligand, x represent the number of coordinating groups in the first organic ligand, a represent the molar ratio of non-coordinated oxygen atoms bonded to metal M to metal M, and b represent the molar ratio of the first organic ligand to metal M, where:

[0082] R is selected from C3 to C19 hydrocarbon groups, preferably from C5 to C11 normal alkyl, C5 to C11 isoalkyl, C5 to C12 cycloalkyl or C6 to C12 aryl;

[0083] x is 1, 2 or 3, preferably 1 or 2;

[0084] a is any value in the range of 0 to 3, preferably any value in the range of 1 to 3; and,

[0085] b is any value in the range of 1 to 6, preferably any value in the range of 2 to 5.

[0086] According to this disclosure, "C3-C19 hydrocarbon group" refers to a hydrocarbon group having 3 to 19 carbon atoms. The hydrocarbon group can be a saturated or unsaturated straight-chain, branched, or carbon ring hydrocarbon group, including but not limited to C3-C19 normal alkyl, C3-C19 isoalkyl, C5-C19 cycloalkyl and C6-C19 aryl.

[0087] According to this disclosure, "C5-C11 n-alkyl" refers to a straight-chain alkyl group having 5 to 11 carbon atoms, such as n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, and n-undecyl.

[0088] According to this disclosure, "C5-C11 isoalkyl" refers to branched alkyl groups having 5 to 11 carbon atoms, such as isopentyl, isohexyl, isoheptyl, isooctyl, isononyl, isodecyl, and isoundecyl.

[0089] According to this disclosure, "C5-C12 cycloalkyl group" refers to a saturated hydrocarbon group containing a saturated carbon ring having 5-12 carbon atoms, such as cyclopentyl, cyclohexyl, methylcyclohexyl, decahydronaphthyl, methyldecahydronaphthyl, ethyldecahydronaphthyl, etc.

[0090] According to this disclosure, "C6-C12 aryl" refers to a group containing an aromatic ring having 6 to 12 carbon atoms, such as phenyl, naphthyl, anthracene, p-tolyl, benzyl, methylnaphthyl, etc.

[0091] According to this disclosure, the C3-C19 hydrocarbon group, C5-C11 normal alkyl group, C5-C11 isoalkyl group, C5-C12 cycloalkyl group and C6-C12 aryl group may be optionally substituted, for example, they may be unsubstituted, or they may be substituted by one or more groups selected from halogen, nitro, sulfonic acid group and the like.

[0092] In one embodiment, M includes M 1 and M 2 M 1 and M 2 They are different from each other. In this disclosure, the catalyst may contain two different metals, wherein the ligands of the two metals can be adjusted as needed.

[0093] In a preferred embodiment, the metallic element is selected from one or more of V, Cr, Mo, W, Fe, Co, Ru, Ni, Cu and Pd, and is preferably selected from one or more of Mo, Ni, W, Fe, V and Co.

[0094] The first organic ligand is selected from organic carboxylic acids of C4 to C20, preferably one or more selected from normal or isomeric alkyl carboxylic acids of C4 to C20, cycloalkanic carboxylic acids containing saturated carbocyclic rings of C6 to C20, and aromatic carboxylic acids containing aromatic rings of C7 to C20. More preferably, it is selected from one or more selected from normal or isomeric alkyl carboxylic acids of C6 to C12, cycloalkanic carboxylic acids containing saturated carbocyclic rings of C6 to C13, and aromatic carboxylic acids containing aromatic rings of C7 to C13. Further preferably, it is selected from one or more selected from succinic acid, hexanoic acid, adipic acid, heptanoic acid, octanoic acid, nonanoic acid, ethylhexanoic acid, oleic acid, petroleum ether, salicylic acid, benzoic acid, and phenylacetic acid.

[0095] In one embodiment, based on the total weight of the second oil-soluble catalyst, the metal content of the catalyst, expressed in metallic form, is 5-35% by weight, preferably 8-30% by weight, more preferably 10-25% by weight, and particularly preferably 10-20% by weight.

[0096] In one embodiment, the infrared spectrum of the catalyst is in the range of 700–1000 cm⁻¹. -1 1350~1450cm -1 and 1500~1610cm -1 It has a characteristic peak at the location.

[0097] In this disclosure, the second oil-soluble catalyst can be purchased commercially or prepared by known methods.

[0098] In one specific embodiment, the second oil-soluble catalyst can be prepared by a method including the following steps:

[0099] A metal-organic acid complex and an organic treatment agent are mixed to obtain a mixture. The mixture is then heated to remove some of the organic ligands from the metal-organic acid complex while retaining the organic treatment agent, yielding the remaining material. The metal-organic acid complex comprises an active metal central atom or central ion and an organic ligand coordinated to the active metal central atom or central ion. The active metal is selected from one or more of Group VB, Group VIB, Group VIII, and Group IB metals with hydrogenation properties. The organic ligand comprises a hydrocarbon moiety and a coordinating group moiety, wherein the coordinating group is a -C(=O)-O group and forms a coordinate bond with the metal central atom or central ion through an oxygen atom. The reaction conditions are conventional, or can be adjusted as needed, and the raw material ratio can be adjusted according to the target catalyst composition.

[0100] In one embodiment, the organometallic acid complex has the illustrative composition shown in general formula (I):

[0101] MOa [R(COO) x ] b (I),

[0102] Where M represents metal, and R(COO) x Represents the organic ligand, R represents the hydrocarbon group in the organic ligand, COO represents the coordinating group in the organic ligand, x represents the number of coordinating groups in the organic ligand, a represents the molar ratio of non-coordinated oxygen atoms bonded to metal M to metal M, and b represents the molar ratio of the organic ligand to metal M, where:

[0103] R is a C3-C19 hydrocarbon group, preferably selected from C5-C11 normal or isomeric alkyl, C5-C12 cycloalkyl and C6-C12 aryl;

[0104] x is 1, 2 or 3, preferably 1 or 2;

[0105] a is a positive number from 0 to 5, preferably a positive number from 1 to 3;

[0106] The infrared spectra of the aforementioned organometallic acid complexes are in the range of 700-1000 cm⁻¹. -1 1350-1450cm -1 and 1500-1610cm -1 The position has a characteristic peak; the group VB metal, group VIB metal, group VIII metal and group IB metal with hydrogenation performance are selected from V, Cr, Mo, W, Fe, Co, Ru, Ni, Cu and Zn, preferably selected from V, Mo, W, Fe, Co, Ni, Cu and Zn, and more preferably selected from Mo, Ni and Co;

[0107] The organic ligand is derived from C4-C20 organic carboxylic acids and / or the anhydrides of C4-C20 organic carboxylic acids, wherein the organic carboxylic acid is preferably selected from one or more of C4-C20 normal or isomeric alkyl carboxylic acids, C6-C20 cycloalkane carboxylic acids containing saturated carbocyclic rings and C7-C20 aromatic carboxylic acids containing aromatic rings, and preferably selected from one or more of C4-C12 normal or isomeric alkyl carboxylic acids, C6-C13 cycloalkane carboxylic acids containing saturated carbocyclic rings and C7-C13 aromatic carboxylic acids containing aromatic rings;

[0108] The organic treatment agent is selected from one or more of the following: alkanes with C>17, monocyclic aromatic hydrocarbons with side chains C>14, aromatic hydrocarbons with not less than 2 aromatic rings, dodecylbenzene sulfonic acid, oleic acid, oleylamine, stearic acid, hexadecyltrimethylammonium bromide, ethylenediaminetetraacetic acid, diesel oil, paraffin wax, ceresin wax, oil slurry, residual oil, asphalt, and coal tar.

[0109] In the metal-organic acid complex, the molar ratio between the active metal and the organic ligand is 1:(1-10).

[0110] In one embodiment, the second oil-soluble catalyst is used in the form of a catalyst composition comprising the second oil-soluble catalyst and at least one second organic ligand compound and / or organic solvent, wherein,

[0111] The second organic ligand compound is selected from C4-C20 organic carboxylic acids, preferably from one or more of C4-C20 normal or isomeric alkyl carboxylic acids, C6-C20 cycloalkane carboxylic acids containing saturated carbocyclic rings, and C7-C20 aromatic carboxylic acids containing aromatic rings, more preferably from one or more of C6-C12 normal or isomeric alkyl carboxylic acids, C6-C13 cycloalkane carboxylic acids containing saturated carbocyclic rings, and C7-C13 aromatic carboxylic acids containing aromatic rings, and even more preferably from one or more of succinic acid, hexanoic acid, adipic acid, heptanoic acid, octanoic acid, nonanoic acid, ethylhexanoic acid, oleic acid, petroleum ether, salicylic acid, benzoic acid, and phenylacetic acid;

[0112] Optionally, the organic solvent is selected from one or more of aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, alcohol solvents, ether solvents, ester solvents and ketone solvents, and preferably from one or more of toluene, gasoline, ethanol and diesel.

[0113] In one embodiment, the catalyst composition comprises at least one of the second organic ligand compounds, and the infrared spectrum of the catalyst composition is in the range of 700–1000 cm⁻¹. -1 1350~1450cm -1 1500~1610cm -1 and 1700~1750cm -1 It has a characteristic peak at the location;

[0114] Preferably, based on the total weight of the catalyst composition, the content of the second oil-soluble catalyst is 50-95% by weight, preferably 80-95% by weight; and the total content of the second organic ligand compound and the organic solvent is 5-50% by weight, preferably 5-20% by weight.

[0115] In some embodiments, the catalyst composition may also include other components that improve oil solubility, storage stability and antioxidant properties, such as organic compounds with reducing properties, such as formic acid, oxalic acid, formaldehyde, ethylenediamine, oleylamine, etc. The content of the other components may be 0-80% based on the weight of the composition, preferably 0-50%.

[0116] In one embodiment, in step S1, the waste plastic pyrolysis oil is obtained by subjecting the waste plastic raw material to one or more of the following methods: thermal cracking, thermal pyrolysis, catalytic cracking, and catalytic pyrolysis.

[0117] Preferably, the chlorine content in the waste plastic pyrolysis oil is below 10,000 μg / g, more preferably 100–5,000 μg / g; optionally, the final boiling point of the waste plastic pyrolysis oil is below 700°C.

[0118] In one specific embodiment, the waste plastic raw materials include one or more of polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), and polyester (PET).

[0119] In one embodiment, step S1 includes:

[0120] The waste plastic pyrolysis oil and the catalyst are mixed and then subjected to a first preheating treatment to obtain a preheated raw material mixture; preferably, the temperature of the preheated raw material mixture is 100-350℃, more preferably 200-300℃; the mixing treatment can make the catalyst uniformly dispersed in the waste plastic pyrolysis oil, which is more conducive to the hydrothermal conversion reaction;

[0121] Hydrogen gas is subjected to a second preheating treatment to obtain preheated hydrogen gas; preferably, the temperature of the preheated hydrogen gas is 150-450°C, more preferably 200-400°C;

[0122] The preheated raw material mixture and preheated hydrogen are introduced into the reactor through the bottom of the reactor; optionally, the reactor is a slurry bed reactor.

[0123] In one specific embodiment, the mixing process employs one or more of mechanical stirring, static mixing, and ultrasonic dispersion.

[0124] In one specific embodiment, a gas distributor is provided in the slurry bed reactor.

[0125] In one embodiment, in step S1, the conditions for the moderate catalytic hydrothermal conversion reaction include:

[0126] The reaction temperature is 150–450℃, preferably 200–400℃, and more preferably 200–350℃; the hydrogen partial pressure is 0.1–15 MPa, preferably 2–10 MPa; and the liquid hourly space velocity is 0.05–10 h⁻¹. -1 Preferably 0.1 to 5 hours -1 More preferably 0.1–0.2 h -1 The catalyst concentration is 0.1–20000 μg / g, preferably 500–15000 μg / g; the hydrogen-to-oil volume ratio is 0.1–1000 Nm. 3 / m 3 Preferably 50-500 Nm 3 / m 3By conducting the reaction under the optimized conditions described in this embodiment, the dechlorination effect of waste plastic pyrolysis oil can be further improved.

[0127] In one embodiment, in step S2, the operating conditions of the thermal high-resolution analyzer include:

[0128] The temperature is 100–400℃ and the pressure is 0.1–15 MPa; preferably, the temperature is 150–350℃ and the pressure is 2–10 MPa.

[0129] In one embodiment, in step S3, the conditions for the alkaline washing treatment include: the pH of the alkaline solution is above 10, and the alkaline solution is selected from sodium hydroxide solution.

[0130] In one embodiment, the method further includes:

[0131] At least a portion of the purified gas obtained in step S3 is returned to step S1 as recycled hydrogen for continued use.

[0132] In a preferred embodiment, the volume ratio of recycled hydrogen to fresh hydrogen is 0 to 1.2:1, preferably 0.5 to 1:1;

[0133] Optionally, the hydrogen purity in the purified gas obtained in step S3 is above 85% by volume.

[0134] In one embodiment, the conditions for water injection treatment in step S4 include:

[0135] The temperature of the liquid product at the water injection point is above 150°C, preferably 150-250°C; the temperature of the water is 20-50°C; and the mass ratio of the water injection volume to the liquid product is 0.5-10:1, preferably 1-5:1.

[0136] Optionally, the water used for water injection treatment is selected from one or more of demineralized water, deoxygenated water, and condensate.

[0137] In one embodiment, the catalyst in the liquid product is recovered by a method including the following steps: filtration or centrifugation.

[0138] In one specific implementation, the following is adopted: Figure 1 The process shown in the flow chart includes the following steps:

[0139] Waste plastic pyrolysis oil 1, catalyst 2, and hydrogen 3 are preheated to a certain temperature and mixed before entering a slurry bed reactor I for a mild catalytic hydrothermal conversion reaction to obtain the catalytic hydrothermal conversion reaction product. The product enters a thermal high-efficiency separator II for gas-liquid separation. The gas phase product is cooled by a gas cooler III and then enters an alkaline washing tower IV to remove acidic gases such as hydrogen chloride to obtain gaseous product 7. The liquid phase product is cooled and then injected with water 9 before entering an oil-water separator V to remove inorganic chlorides from the product, resulting in wastewater 10 and low-chlorine product 11.

[0140] The present disclosure is further described in detail below through examples. All raw materials used in the examples are commercially available.

[0141] The composition of the waste plastic pyrolysis oil used in the following examples and comparative examples is listed in Table 1.

[0142] Example 1

[0143] (1) Waste plastic pyrolysis oil, catalyst, and hydrogen are preheated to a certain temperature (300℃) and mixed before being fed into a slurry bed reactor for a mild catalytic hydrothermal conversion reaction to obtain the hydrothermal conversion reaction products. The conditions for the hydrothermal conversion reaction include: temperature 350℃; hydrogen partial pressure 5MPa; volume hourly space velocity 0.17h. -1 The catalyst concentration is 10000 μg / g; the hydrogen-to-oil ratio is 100 Nm. 3 / m 3 The catalyst is molybdenum ethylhexanoate;

[0144] (2) The products of the hydrogen thermal conversion reaction enter the thermal high-performance separator for gas-liquid separation; the operating conditions of the thermal high-performance separator include: temperature of 250℃ and pressure of 4MPa;

[0145] (3) After cooling, the gaseous product is washed with alkali to remove acidic gases such as hydrogen chloride. The pH of the alkali solution (sodium hydroxide solution) is 11. The temperature of the gaseous product entering the alkali washing solution is 160℃.

[0146] (4) After cooling, the liquid product is injected with water and then separated into oil and water to remove inorganic chlorides from the product. The water injection point temperature is 180℃, the water temperature is 25℃, and the mass ratio of water injection to liquid product is 2:1.

[0147] Example 2

[0148] (1) Waste plastic pyrolysis oil, catalyst, and hydrogen are preheated to a certain temperature (300℃) and mixed before being fed into a slurry bed reactor for a mild catalytic hydrothermal conversion reaction to obtain the hydrothermal conversion reaction products. The conditions for the hydrothermal conversion reaction include: temperature 350℃; hydrogen partial pressure 5MPa; volume hourly space velocity 0.33h. -1 The catalyst concentration is 10000 μg / g; the hydrogen-to-oil ratio is 100 Nm. 3 / m3 The catalyst is molybdenum ethylhexanoate;

[0149] (2) The products of the hydrogen thermal conversion reaction enter the thermal high-performance separator for gas-liquid separation; the operating conditions of the thermal high-performance separator include: temperature of 250℃ and pressure of 4MPa;

[0150] (3) After cooling, the gaseous product is washed with alkali to remove acidic gases such as hydrogen chloride. The pH of the alkali solution is 11. The temperature of the gaseous product entering the alkali washing solution is 160℃.

[0151] (4) After cooling, the liquid product is injected with water and then separated into oil and water to remove inorganic chlorides from the product. The water injection point temperature is 180℃, the water temperature is 25℃, and the mass ratio of water injection to liquid product is 2:1.

[0152] Example 3

[0153] (1) Waste plastic pyrolysis oil, catalyst, and hydrogen are preheated to a certain temperature (350℃) and mixed before being fed into a slurry bed reactor for a mild catalytic hydrothermal conversion reaction to obtain the hydrothermal conversion reaction products. The conditions for the hydrothermal conversion reaction include: temperature 380℃; hydrogen partial pressure 5MPa; volume hourly space velocity 0.33h. -1 The catalyst concentration is 10000 μg / g; the hydrogen-to-oil ratio is 100 Nm. 3 / m 3 The catalyst is molybdenum ethylhexanoate;

[0154] (2) The products of the hydrogen thermal conversion reaction enter the thermal high-performance separator for gas-liquid separation; the operating conditions of the thermal high-performance separator include: temperature of 250℃ and pressure of 4MPa;

[0155] (3) After cooling, the gaseous product is washed with alkali to remove acidic gases such as hydrogen chloride. The pH of the alkali solution is 11. The temperature of the gaseous product entering the alkali washing solution is 160℃.

[0156] (4) After cooling, the liquid product is injected with water and then separated into oil and water to remove inorganic chlorides from the product. The water injection point temperature is 180℃, the water temperature is 25℃, and the mass ratio of water injection to liquid product is 2:1.

[0157] Example 4

[0158] This embodiment refers to the method in Example 1, except that the catalyst is replaced with iron organic carboxylate; the rest of the process is the same as in Example 1.

[0159] Example 5

[0160] This embodiment refers to the method in Embodiment 1, but differs from Embodiment 1 in that:

[0161] The gas after alkaline washing is returned to step S1 as recycled hydrogen for continued use; the volume ratio of recycled hydrogen to fresh hydrogen is 1:1; wherein the hydrogen purity in the purified gas obtained after alkaline washing is above 85% by volume.

[0162] Example 6

[0163] This embodiment follows the experimental method described in Example 1, except that it uses the catalyst Mo. 0.5 Ni 0.5 O 1.5 (i-C7H 15 COO) 2.60 The molar ratio of metal element to first organic ligand is 1:2.6. Based on the total weight of the oil-soluble catalyst, the metal element is expressed in metallic form, and the metal content of the catalyst is 15.8% by weight.

[0164] The oil-soluble catalyst is used in the form of a catalyst composition comprising an oil-soluble catalyst and at least one second organic ligand compound, wherein the second organic ligand compound is isooctanoic acid, and the content of the oil-soluble catalyst is 90% by weight based on the total weight of the catalyst composition.

[0165] The catalyst was prepared by the following method:

[0166] A metal-containing compound is added to a three-necked flask, followed by the addition of an organic carboxylic acid in a molar ratio of 1-10 to the metal, and the mixture is stirred. The mixture is then reacted at 160-260°C for 5 hours to obtain an oily organometallic acid complex. The obtained organometallic acid complex and an organic treatment agent are then added to a three-necked flask and the reaction is carried out. The gas produced during the reaction is separated. After the reaction is completed, the liquid product in the flask is poured out to obtain an oil-soluble catalyst.

[0167] Among them, the organometallic acid complex is Mo 0.5 Ni 0.5 O 1.5 (i-C7H 15 COO) 2.60 The molar ratio between the active metal and the organic ligand in the organometallic acid complex is 1:2.6, the organic treatment agent is toluene, the mass ratio of the metal to the organic treatment agent in the organometallic acid complex is 1:0.65, the reaction temperature is 260℃, the reaction time is 4h, and the molar ratio between the active metal and the organic ligand in the catalyst is 1:1.15.

[0168] The method for determining the metal content in the metal-organic acid complex of the raw material used in the catalyst is as follows: The test sample is diluted 200 times with an organic solvent and then measured using inductively coupled plasma optical emission spectrometry (ICP-OES) with a SPECTRO ARCOS SOP plasma optical emission spectrometer. The measurement conditions are: the optical chamber is sealed and filled with argon gas, vertical observation is performed, and the wavelength range is 130-770 nm.

[0169] Example 7

[0170] This embodiment follows the experimental method described in Example 1, but differs from Example 1 in that it uses a catalyst (Mo). 0.5 Co 0.5 )O 1.27 (C7H 16 COO) 2.45 The molar ratio of metal element to first organic ligand is 1:2.45. Based on the total weight of the oil-soluble catalyst, the metal element is expressed in metallic form, and the metal content of the catalyst is 14.5% by weight.

[0171] The oil-soluble catalyst is used in the form of a catalyst composition comprising an oil-soluble catalyst and at least one second organic ligand compound, wherein the second organic ligand compound is isooctanoic acid, and the content of the oil-soluble catalyst is 91% by weight based on the total weight of the catalyst composition.

[0172] The preparation method of this catalyst is the same as that of the catalyst in Example 6, wherein the metal-organic acid complex is (Mo 0.5 Co 0.5 )O 1.27 (C7H 16 COO) 2.45 The molar ratio between the active metal and the organic ligand in the organometallic acid complex is 1:2.45, the organic treatment agent is toluene, the mass ratio of the metal to the organic treatment agent in the organometallic acid complex is 1:0.65, the reaction temperature is 220℃, the reaction time is 6h, and the molar ratio between the active metal and the organic ligand in the catalyst is 1:1.1.

[0173] Comparative Example 1

[0174] (1) Waste plastic pyrolysis oil and hydrogen are preheated to a certain temperature (350℃) and mixed before entering a slurry bed reactor for a mild hydrothermal conversion reaction to obtain the hydrothermal conversion reaction product. The conditions for the hydrothermal conversion reaction include: temperature 350℃; hydrogen partial pressure 5MPa; volume hourly space velocity 0.33h. -1 The hydrogen-to-oil ratio is 100 Nm. 3 / m 3 No catalyst added;

[0175] (2) The products of the hydrogen thermal conversion reaction enter the thermal high-performance separator for gas-liquid separation; the operating conditions of the thermal high-performance separator include: temperature of 250℃ and pressure of 4MPa;

[0176] (3) After cooling, the gaseous product is washed with alkali to remove acidic gases such as hydrogen chloride. The temperature of the gaseous product entering the alkali wash is 160℃.

[0177] (4) After cooling, the liquid product is injected with water and then separated into oil and water to remove inorganic chlorides from the product. The water injection point temperature is 180℃, the water temperature is 25℃, and the mass ratio of water injection to liquid product is 2:1.

[0178] Comparative Example 2

[0179] (1) Waste plastic pyrolysis oil and nitrogen gas are preheated to a certain temperature (350℃) and mixed before entering a slurry bed reactor for a mild thermal conversion reaction to obtain thermal conversion reaction products. The conditions for the thermal conversion reaction include: temperature 350℃; hydrogen partial pressure 0MPa; volume hourly space velocity 0.33h. -1 No catalyst added;

[0180] (2) The products of the thermal conversion reaction enter the thermal high-performance separator for gas-liquid separation; the operating conditions of the thermal high-performance separator include: temperature of 250℃ and pressure of 4MPa;

[0181] (3) After cooling, the gaseous product is washed with alkali to remove acidic gases such as hydrogen chloride. The temperature of the gaseous product entering the alkali wash is 160℃.

[0182] (4) After cooling, the liquid product is injected with water and then separated into oil and water to remove inorganic chlorides from the product. The water injection point temperature is 180℃, the water temperature is 25℃, and the mass ratio of water injection to liquid product is 2:1.

[0183] The composition of the waste plastic pyrolysis oil used in the above embodiments and comparative examples is listed in Table 1 below.

[0184] Table 1

[0185] <![CDATA[Density (20 °C) / (kg / m 3 )]]> 831.9 Carbon residue value / wt% 0.74 Bromine value, gBr / 100mL 37.1 element C / wt% 87.72 H / wt% 12.27 S, mg / kg 439 N, mg / kg 1400 Cl, mg / kg 2980 Si, mg / kg 505 Simulated distillation range / ℃ Initial boiling point 23 10 81 30 136 50 179 70 273 99.5 (final boiling point) 549

[0186] The reaction conditions and product properties of the above examples and comparative examples are shown in Table 2 below.

[0187] Table 2

[0188]

[0189] As shown in Table 2, the method provided in this disclosure in Examples 1-7 can achieve a high dechlorination rate. Especially under the preferred conditions, the dechlorination rate is as high as 98.66%, and the chlorine content is reduced from 2980 mg / kg to 40 mg / kg, resulting in pyrolysis oil with a low chlorine content. At the same time, the bromine value of the plastic pyrolysis oil is reduced from 37.1 gBr / 100 mL to 15.7 gBr / 100 mL, indicating that the content of unsaturated hydrocarbons is significantly reduced, the stability of the pretreated product is higher, and high-quality raw materials are provided for subsequent processing.

[0190] In comparison with Comparative Example 1 (hydrothermal conversion reaction without adding catalyst), the dechlorination rate of waste plastic oil pyrolysis oil treated by the method provided in this disclosure in Example 1 is significantly improved compared with Comparative Example 1.

[0191] Compared to Comparative Example 2 (which involved thermal conversion without a catalyst under nitrogen conditions), Example 1 showed a significant improvement in both liquid yield and dechlorination rate.

[0192] Compared with Example 2, Example 2 increased the volume hourly space velocity for the hydrothermal conversion reaction. Although the yield of the liquid phase product in Example 2 was slightly improved, Example 1 achieved a higher dechlorination rate, a lower bromine value, and better stability of the liquid phase product.

[0193] Comparing Example 1 and Example 3, Example 3 increased the reaction temperature and space velocity, while the dechlorination rate and liquid yield of Example 1 were higher than those of Example 3.

[0194] Compared with Example 1, Example 5 uses the gas after alkaline washing as recycled hydrogen. The liquid yield and dechlorination rate of Example 5 can reach the same level as those of Example 1. This method can also realize gas recycling, which improves the overall resource utilization of the process.

[0195] Comparing Examples 1, 6-7 with Example 4, Examples 1 and 6-7 use the oil-soluble catalyst provided in this disclosure, and the liquid yield and dechlorination effect of Examples 1, 6-7 are better than those of Example 4.

[0196] Comparing Example 1 with Examples 6-7, Examples 6-7 used a second oil-soluble catalyst. The treatment effect of waste plastic pyrolysis oil in Examples 6-7 was comparable to that in Example 1, but the catalysts in Examples 6-7 had a significant cost advantage.

[0197] The preferred embodiments of this disclosure have been described in detail above. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0198] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0199] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A method for treating chlorine-containing waste plastic pyrolysis oil, characterized in that, Includes the following steps: S1. The waste plastic pyrolysis oil, catalyst, and hydrogen are brought into contact in a reactor to carry out a moderate catalytic hydrothermal conversion reaction, yielding the thermal conversion reaction products; the liquid hourly space velocity (LHSV) of the moderate catalytic hydrothermal conversion reaction is 0.1~0.2 h⁻¹. -1 The reactor is a slurry bed reactor. S2. The thermal conversion reaction products are fed into a thermal high-efficiency separator for gas-liquid separation to obtain gaseous and liquid products. S3. The gaseous product is subjected to alkaline washing to obtain a purified gaseous phase. S4. The liquid phase product is subjected to water injection treatment and then oil-water separation treatment to obtain a dechlorinated oil phase product. The catalyst is selected from one or more of a first oil-soluble catalyst and a second oil-soluble catalyst. The first oil-soluble catalyst includes a molybdenum-containing organic compound, and the second oil-soluble catalyst includes a complex formed by a metal central atom or metal central ion and a first organic ligand through a coordination bond. The first oil-soluble catalyst is selected from one or more of molybdenum carbonyl, molybdenum naphthenate, molybdenum ethyl-hexanoate, and molybdenum dialkyldithiocarbamate; the metal element in the metal central atom or metal central ion is selected from one or more of V, Cr, W, Fe, Co, Ru, Ni, Cu, and Pd; and the first organic ligand is selected from C4-C20 organic carboxylic acids.

2. The method according to claim 1, characterized in that, The second oil-soluble catalyst has the composition shown in formula (I): MO a [R(COO) x ] b (I), Where M represents the metal; R is selected from C3~C19 hydrocarbon groups. x is 1, 2, or 3; a is any value in the range of 0 to 3; and b is any value in the range of 1 to 6.

3. The method according to claim 2, characterized in that, R is selected from C5~C11 normal alkyl, C5~C11 isoalkyl, C5~C12 cycloalkyl or C6~C12 aryl; x is 1 or 2; a is any value in the range of 1 to 3; and b is any value in the range of 2 to 5; M includes M 1 and M 2 M 1 and M 2 They are different from each other.

4. The method according to claim 1, characterized in that, The metallic element is selected from one or more of Ni, W, Fe, V and Co; The first organic ligand is selected from one or more of the following: C4-C20 normal or isomeric alkyl carboxylic acids, C6-C20 cycloalkanic carboxylic acids containing saturated carbocyclic rings, and C7-C20 aromatic carboxylic acids containing aromatic rings.

5. The method according to claim 4, characterized in that, The first organic ligand is selected from one or more of the following: C6-C12 normal or isomeric alkyl carboxylic acids, C6-C13 cycloalkane carboxylic acids containing saturated carbocyclic rings, and C7-C13 aromatic carboxylic acids containing aromatic rings.

6. The method according to claim 5, characterized in that, The first organic ligand is selected from one or more of succinic acid, hexanoic acid, adipic acid, heptanoic acid, octanoic acid, nonanoic acid, ethylhexanoic acid, oleic acid, petroleum ether, salicylic acid, benzoic acid and phenylacetic acid.

7. The method according to claim 1, characterized in that, Based on the total weight of the second oil-soluble catalyst, the metal content of the catalyst is 5-35% by weight, calculated in metallic form.

8. The method according to claim 7, characterized in that, Based on the total weight of the second oil-soluble catalyst, and with the metal elements expressed in metallic form, the metal content of the catalyst is 8-30% by weight. The molar ratio of the metal element to the first organic ligand is 1:(0.5~3.5).

9. The method according to claim 8, characterized in that, Based on the total weight of the second oil-soluble catalyst, and with the metal elements expressed in metallic form, the metal content of the catalyst is 10-25% by weight. The molar ratio of the metal element to the first organic ligand is 1:(1.5~2.5).

10. The method according to claim 9, characterized in that, Based on the total weight of the second oil-soluble catalyst, the metal content of the catalyst is 10-20% by weight, with the metal elements expressed in metallic form.

11. The method according to claim 1, characterized in that, The second oil-soluble catalyst is used in the form of a catalyst composition comprising the second oil-soluble catalyst and at least one second organic ligand compound and / or organic solvent, wherein, The second organic ligand compound is selected from C4-C20 organic carboxylic acids.

12. The method according to claim 11, characterized in that, The second organic ligand compound is selected from one or more of the following: C4-C20 normal or isomeric alkyl carboxylic acids, C6-C20 cycloalkane carboxylic acids containing saturated carbocyclic rings, and C7-C20 aromatic carboxylic acids containing aromatic rings.

13. The method according to claim 12, characterized in that, The second organic ligand compound is selected from one or more of the following: C6-C12 normal or isomeric alkyl carboxylic acids, C6-C13 cycloalkane carboxylic acids containing saturated carbocyclic rings, and C7-C13 aromatic carboxylic acids containing aromatic rings.

14. The method according to claim 13, characterized in that, The second organic ligand compound is selected from one or more of succinic acid, hexanoic acid, adipic acid, heptanoic acid, octanoic acid, nonanoic acid, ethylhexanoic acid, oleic acid, petroleum ether, salicylic acid, benzoic acid, and phenylacetic acid.

15. The method according to claim 14, characterized in that, The organic solvent is selected from one or more of aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, alcohol solvents, ether solvents, ester solvents, and ketone solvents.

16. The method according to claim 15, characterized in that, The organic solvent is selected from one or more of toluene, gasoline, ethanol and diesel.

17. The method according to claim 11, characterized in that, The catalyst composition comprises at least one of the second organic ligand compounds; Based on the total weight of the catalyst composition, the content of the second oil-soluble catalyst is 50-95% by weight, and the total content of the second organic ligand compound and the organic solvent is 5-50% by weight.

18. The method according to claim 17, characterized in that, Based on the total weight of the catalyst composition, the content of the second oil-soluble catalyst is 80-95% by weight, and the total content of the second organic ligand compound and organic solvent is 5-20% by weight.

19. The method according to claim 1, characterized in that, In step S1, the waste plastic pyrolysis oil is obtained by subjecting the waste plastic raw material to one or more of the following methods: thermal cracking, thermal pyrolysis, catalytic cracking, and catalytic pyrolysis. In step S1, the chlorine content in the waste plastic pyrolysis oil is below 10000 μg / g.

20. The method according to claim 19, characterized in that, In step S1, the chlorine content in the waste plastic pyrolysis oil is 100~5000μg / g; the final boiling point of the waste plastic pyrolysis oil is below 700℃.

21. The method according to claim 1, characterized in that, Step S1 includes: The waste plastic pyrolysis oil and catalyst are mixed and then subjected to a first preheating treatment to obtain a preheated raw material mixture; the temperature of the preheated raw material mixture is 100~350℃. Hydrogen gas is subjected to a second preheating treatment to obtain preheated hydrogen gas; the temperature of the preheated hydrogen gas is 150~450℃. The preheated raw material mixture and preheated hydrogen are introduced into the reactor through the bottom of the reactor.

22. The method according to claim 21, characterized in that, The temperature for preheating the raw material mixture is 200~300℃, and the temperature for preheating hydrogen is 200~400℃; The mixing process employs one or more of the following: a mechanical stirring device, a static mixing device, and an ultrasonic dispersion device.

23. The method according to claim 1, characterized in that, In step S1, the conditions for the moderate catalytic hydrothermal conversion reaction include: The reaction temperature was 150–450 °C, the hydrogen partial pressure was 0.1–15 MPa, the catalyst concentration was 0.1–20000 μg / g, and the hydrogen-to-oil volume ratio was 0.1–1000 Nm. 3 / m 3 .

24. The method according to claim 23, characterized in that, In step S1, the conditions for the moderate catalytic hydrothermal conversion reaction include: The reaction temperature is 200~400℃, the hydrogen partial pressure is 2~10MPa, the catalyst concentration is 500~15000μg / g, and the hydrogen-to-oil volume ratio is 50~500Nm. 3 / m 3 .

25. The method according to claim 24, characterized in that, The reaction temperature is 200~350℃.

26. The method according to claim 1, characterized in that, In step S2, the operating conditions of the thermal high-resolution analyzer include: Temperature range: 100~400℃; Pressure range: 0.1~15MPa; In step S3, the conditions for the alkaline washing treatment include: the pH of the alkaline solution is above 10.

27. The method according to claim 26, characterized in that, In step S2, the temperature is 150~350℃ and the pressure is 2~10MPa.

28. The method according to claim 1, characterized in that, The method also includes: At least a portion of the purified gas obtained in step S3 is returned to step S1 as recycled hydrogen for continued use; The volume ratio of recycled hydrogen to fresh hydrogen is 0~1.2:1; The purified gas obtained in step S3 has a hydrogen purity of 85% by volume or higher.

29. The method according to claim 28, characterized in that, The volume ratio of recycled hydrogen to fresh hydrogen is 0.5 to 1:

1.

30. The method according to claim 1, characterized in that, In step S4, the conditions for the water injection treatment include: The temperature of the liquid product at the water injection point is above 150℃, the temperature of the water is 20~50℃, and the mass ratio of the injected water to the liquid product is 0.5~10:

1. The water used for water injection treatment is selected from one or more of demineralized water, deoxygenated water, and condensate.

31. The method according to claim 30, characterized in that, The temperature of the liquid product at the water injection point is 150~250℃, and the mass ratio of water injection volume to liquid product is 1~5:1.

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