CN116554925B

CN116554925B - A method for hydrogenating and purifying waste plastic pyrolysis oil

Info

Publication number: CN116554925B
Application number: CN202310606967.3A
Authority: CN
Inventors: 柴永明; 刘宾; 孙光政; 杨军卫; 潘原; 李奕川; 刘晨光
Original assignee: China University of Petroleum East China
Current assignee: China University of Petroleum East China
Priority date: 2023-05-26
Filing date: 2023-05-26
Publication date: 2024-05-24
Anticipated expiration: 2043-05-26
Also published as: CN116554925A

Abstract

The invention relates to the technical field of petroleum processing, and discloses a waste plastic pyrolysis oil hydrogenation purification method, which comprises the following steps: waste plastic pyrolysis oil and hydrogen are mixed with a hydrogenation catalyst after being respectively preheated, and then enter a slurry bed hydrogenation reactor for hydrogenation; recycling the effluent after hydrogenation to a slurry bed hydrogenation reactor through a solid-containing tailings part separated by a gas-liquid-solid cyclone separator; the gas-liquid mixed product enters a gas-liquid separator, and the liquid-phase product enters a liquid-solid separator; and (3) discharging the solid residues out of the device, and enabling the liquid product to enter a fixed bed hydrogenation reactor for hydrogenation refining to obtain the waste plastic pyrolysis oil after hydrogenation purification. The invention has simple process flow and long service life of the hydrogenation catalyst, adopts slurry bed hydrogenation pretreatment and fixed bed hydrogenation post-refining coupling purification technology, can realize the efficient hydrogenation removal of chlorine, silicon, metal and conjugated diene in waste plastic pyrolysis oil, achieves deep hydrogenation purification effect, greatly improves the quality, is not easy to coke, and has long running period of the device.

Description

Waste plastic pyrolysis oil hydrogenation purification method

Technical Field

The invention relates to the technical field of petroleum processing, in particular to a waste plastic pyrolysis oil hydrogenation purification method.

Background

The plastic products are widely applied and play an important role in human life, but as the plastic products are difficult to degrade in nature, the waste plastics are continuously piled up in the global scope, the total amount of the waste plastics is continuously increased, and the environment is greatly damaged. The waste plastics are pyrolyzed to prepare oil, so that the environmental pollution problem of the waste plastics can be solved, and the shortage problem of petroleum resources can be relieved. However, because the plastic has various types, various additives for improving the plastic performance are not counted, the plastic does not contain sulfur, nitrogen, oxygen, silicon and other heteroatoms and calcium, magnesium, zinc, iron, copper, aluminum and other metal impurities, and the polyvinyl chloride plastic containing high chlorine content is widely applied, the plastic with the property is cracked into oil, and the impurities in the plastic can seriously affect equipment no matter the plastic is used as fuel or chemical products, and the plastic cannot be directly used as petroleum raw materials, so that the plastic cracked oil is further subjected to hydrogenation pretreatment for purification and quality improvement.

The thermal conductivity of the plastic is poor, and the pyrolysis is very easy to be uneven and insufficient in the pyrolysis process, so that substances such as small-particle plastic, coke and the like which are not completely pyrolyzed exist in pyrolysis oil after pyrolysis, and the pyrolysis oil generated by pyrolysis has larger difference in molecular structure due to different types of recycled plastic.

The processes of hydrodesulfurization, denitrification, demetallization, hydrogenation saturation and the like in petroleum refining processing systems are relatively mature, but the researches on dechlorination and desilication are less and not mature enough, the dechlorination mode which is mostly adopted in the industry at present is adsorbent dechlorination, but the chlorine capacity of the adsorbent dechlorination agent is smaller, the adsorbent dechlorination agent is only suitable for petroleum raw materials with lower chlorine content, the content of chlorine in plastic pyrolysis oil is different from hundreds to tens of thousands ppm due to different plastic types, and the plastic pyrolysis oil contains a large amount of hetero atoms and metal ions, so that competitive adsorption is easy to generate and saturation reduction dechlorination effect. The catalytic dechlorination and hydrodechlorination are carried out by converting organic chloride into inorganic hydrogen chloride through a fixed bed reactor and then utilizing metal oxide, hydroxide and the like for adsorption removal, but the existing hydrodechlorination catalyst has few researches, the industrialized dechlorination catalyst is easy to poison and deactivate, the dechlorination effect is influenced, and the polymerization and coking of olefin are easy to occur in the fixed bed hydrogenation catalytic dechlorination process due to higher content of olefin and diene, so that the integral pretreatment effect is not ideal.

The existence of silicon element can be deposited on the surface of the catalyst in the hydrogenation process, and the active center of the catalyst is blocked to cause deactivation. The plastic pyrolysis oil contains a large amount of silicon elements, a common catalyst is difficult to remove, the Exxon mobil pyrolysis oil desilication purification process reacts with organic silicon through a renewable adsorbent, waste regenerated gas containing silicon is generated at high temperature, the silicon is separated from gas and liquid phases, and then the waste regenerated gas is regenerated and can be recycled.

Chinese patent publication No. CN111171865A discloses a method for dechlorinating waste plastic pyrolysis oil, firstly, introducing chlorine-containing plastic pyrolysis oil and hydrogen into a fixed bed reactor to react in the presence of a hydrogenation catalyst, then performing oil-gas separation, mixing the pyrolysis oil after hydrogenation with an adsorbent to perform secondary dechlorination, and then introducing into a separator to perform liquid-solid separation, thereby obtaining dechlorinated plastic pyrolysis oil and waste adsorbent. The mode combines hydrodechlorination and adsorption dechlorination, and the service life and the integral dechlorination effect of the two-stage dechlorination adsorbent can be improved by one-stage hydrodechlorination.

The Chinese patent with publication number CN103980938A discloses a method for producing clean fuel by chlorine-containing plastic oil, which comprises the steps of introducing plastic pyrolysis oil into a catalytic distillation tower for cracking reaction and rectification, introducing the catalytic pyrolysis oil into a low-pressure liquid-phase hydrogenation reactor for hydrodechlorination by using a molecular sieve/alumina catalyst, and adopting a supported catalyst; the dechlorinated pyrolysis oil enters a washing tower, is washed to remove chloridion and then enters a two-stage hydrofining reactor to carry out dealkenation, denitrification, desulfurization, colloid and the like, and a sulfide catalyst is adopted; and then enters a distillation tower to obtain clean naphtha and diesel oil fractions at the top of the distillation tower respectively, and the bottom of the distillation tower still contains a small amount of chlorine to mix and re-react with the pyrolysis oil raw material again. Through the primary catalysis and the two-stage hydrodechlorination reaction, the method has longer process flow, uses more catalysts, and generates poisoning and deactivation on the adopted supported catalyst carrier due to hydrogen chloride generated in the dechlorination process.

Chinese patent publication No. CN110079360a discloses a method for hydrodechlorination of chlorine-containing oil, which comprises introducing chlorine-containing raw material into low pressure hydrodechlorination reactor, introducing hydrogen chloride generated by reaction into dechlorination adsorption reactor for adsorption, removing chlorine, and introducing into gas-liquid separator for separation of dechlorinated purified oil and hydrogen-containing gas phase.

The China institute of petrochemical industry develops a technology for producing low-impurity oil SPWO from waste plastics, and after chlorine-containing pyrolysis oil is prepared by pyrolysis of front-stage plastics, SNCC catalytic pyrolysis is performed after dechlorination by RPCC pretreatment to prepare petrochemical products. The integrated process developed by the Saint basic industry company is used for producing petrochemical products through hydrocracking, dechlorination and hydrogenation saturation after plastic pyrolysis, the process is used for pyrolyzing the plastic firstly, the produced heavy high-carbon hydrocarbon molecules can be hydrocracked into low-carbon hydrocarbon molecule pyrolysis oil and pyrolysis gas through two-stage pyrolysis, the low-carbon hydrocarbon molecule pyrolysis oil and the pyrolysis gas respectively enter a hydrogenation device and a steam cracking device, the pyrolysis oil is refined and dealkened in the hydrogenation device, partial heteroatoms such as chlorine, sulfur and the like are removed, the hydrogen chloride, the hydrogen sulfide and the like are separated after the pyrolysis oil enters a separator, the dechlorination unit is further used for dechlorination, and the steam cracking requirement can be met after dechlorination. The dechlorination mode adopted in the dechlorination unit is that a fixed bed is filled with adsorbent (hematite, alumina and the like) for reaction adsorption dechlorination.

The plastic pyrolysis oil purification of the technology mainly adopts a fixed bed, if the plastic pyrolysis oil is not directly treated by hydrogenation, the catalyst bed is blocked due to the fact that the pyrolysis oil is extremely easy to coke and scale due to the fact that the olefin content of the pyrolysis oil is too high, and the requirement of continuous and stable operation in a long period is difficult to achieve, so that the plastic pyrolysis oil is not suitable for the fixed bed treatment. Most of the currently known dechlorination catalysts adopted in the industrialized process are supported transition metal or noble metal hydrogenation catalysts, no special catalyst for removing organic chlorine exists at present, and the traditional supported catalyst is extremely easy to be poisoned and deactivated by hydrogen chloride in the hydrotreatment of waste plastic pyrolysis oil. Therefore, development of a waste plastic pyrolysis oil treatment process which has strong adaptability to raw materials and can realize large-scale and long-period operation of a device is an important problem to be solved in the field.

Disclosure of Invention

In order to solve the defects existing in the existing waste plastic pyrolysis oil hydrogenation pretreatment process, the invention provides a waste plastic pyrolysis oil hydrogenation purification method, which has the following technical scheme:

A waste plastic pyrolysis oil hydrogenation purification method comprises the following steps:

S101: waste plastic pyrolysis oil and hydrogen are respectively preheated and then mixed with a hydrogenation catalyst, and then enter a slurry bed hydrogenation reactor for hydrogenation pretreatment;

s102: separating the hydrogenated effluent by a gas-liquid-solid cyclone separator to obtain solid-containing tailings, and partially recycling to the inlet of the slurry bed hydrogenation reactor, wherein a small amount of tailings are discharged;

S103: the gas-liquid mixed product obtained by separation of the gas-liquid solid cyclone separator enters the gas-liquid separator to separate the gas product and the liquid phase product, and the liquid phase product enters the liquid-solid separator;

s104: discharging the solid residue separated by the liquid-solid separator, and allowing the liquid product to enter a fixed bed hydrogenation reactor for hydrofining;

S105: obtaining the waste plastic pyrolysis oil after hydrogenation purification after the hydrofining reaction.

Further, the waste plastic pyrolysis oil, hydrogen and a hydrogenation catalyst in the S101 are mixed and then enter a slurry bed hydrogenation reactor from the bottom to flow from bottom to top; the slurry bed hydrogenation reactor has the following reaction conditions: the hydrogen partial pressure in the reactor is 6-15 MPa, the reaction temperature is 330-410 ℃, the liquid hourly space velocity is 0.5-2 h ^-1, and the volume ratio of hydrogen to waste plastic pyrolysis oil is 400-1200 Nm ³/m³.

Further, the addition amount of the hydrogenation catalyst in the S101 accounts for 0.005-0.2 wt% of the waste plastic pyrolysis oil.

Further, the temperature after the hydrogen is preheated in the S101 is 350-500 ℃, and the temperature after the waste plastic pyrolysis oil is preheated is 150-300 ℃; the operation conditions of the gas-liquid-solid cyclone separator in the step S102 are as follows: the pressure is 6-15 MPa, and the temperature is 200-300 ℃; and S102, separating the obtained tailings by a gas-liquid-solid cyclone separator, wherein the amount of the tailings recycled to the inlet of the slurry bed hydrogenation reactor accounts for 80% -98% of the total amount of the tailings, and the external discharge amount accounts for 2% -20% of the total amount of the tailings.

Further, the hydrofining catalyst in S101 is a VIB group metal Mo or W and a VIII group metal Co or Ni which are loaded on a carrier, and the active components of the catalyst are 10-30% by weight of oxide.

Further, the composition of the hydrogenation catalyst in S101 is: 1 to 6 weight percent of nickel oxide and/or cobalt oxide, 6 to 24 weight percent of molybdenum oxide and/or tungsten oxide, and the balance of silicon oxide-aluminum oxide; silica-alumina: the silica content is 10 to 40 wt% and the alumina content is 60 to 90 wt% based on the carrier.

Further, the reaction conditions of the fixed bed hydrogenation reactor in S104 are as follows: the hydrogen partial pressure in the reactor is 6-15 MPa, the reaction temperature is 300-380 ℃, the liquid hourly space velocity is 0.5-2 h ^-1, and the volume ratio of the hydrogen to the liquid product separated by the liquid-solid separator is 300-800 Nm ³/m³.

Further, the preparation steps of the hydrogenation catalyst in S101 are as follows:

(1) Fully mixing and stirring aluminum hydroxide dry rubber powder and silicon dioxide powder, and kneading into a uniform powder mixture;

(2) Fully contacting the prepared powder mixture with sprayed adhesive and water, and preparing spherical shaped objects by adopting a spray granulation mode; the amount of the binder is 3-10 wt% of the powder mixture, and the composition of the binder is as follows: 20-50% by weight of silica sol, 20-50% by weight of aluminum sol and 1-30% by weight of forming additive; the forming auxiliary agent is one or more of polyethylene glycol, citric acid, ethylenediamine tetraacetic acid and methyl cellulose;

(3) Roasting the spherical shaped objects in air atmosphere to obtain spherical catalyst carriers, wherein the roasting temperature is 200-600 ℃ and the roasting time is 1-8 hours;

(4) Preparing the active metal soluble salt into a solution with a required concentration, impregnating the prepared spherical carrier by adopting an equal volume impregnation method, drying for 1-10 hours at 50-120 ℃, and roasting for 1-10 hours at 200-500 ℃ to prepare a hydrogenation catalyst; the active metal soluble salts comprise nickel salts, cobalt salts, molybdenum salts and tungsten salts, wherein the nickel salts comprise nickel nitrate and basic nickel carbonate, the cobalt salts comprise cobalt nitrate, cobalt acetate and basic cobalt carbonate, the molybdenum salts comprise molybdenum oxide and ammonium molybdate, and the tungsten salts comprise tungsten oxide and ammonium metatungstate.

Further, the hydrogenation catalyst is spherical and has an outer diameter of 50-500 μm.

Further, the waste plastic pyrolysis oil comprises liquid oil prepared by anaerobic pyrolysis, hydropyrolysis or catalytic pyrolysis of various waste plastic products, waste tires, rubber and the like; the waste plastic pyrolysis oil hydrogenation purification method is also suitable for the hydrogenation purification treatment of waste lubricating oil.

Compared with the prior art, the invention has the following beneficial technical effects:

1. by adopting the slurry bed hydrogenation pretreatment and fixed bed hydrogenation post-refining coupling purification process, the efficient hydrogenation removal of chlorine, silicon, metal and conjugated diene in the waste plastic pyrolysis oil can be realized, and the deep hydrogenation purification effect is achieved.

2. The quality of waste plastic pyrolysis oil is greatly improved.

3. Is not easy to coke and prolongs the operation period of the hydrogenation purification device.

4. The process flow is simple.

5. The hydrogenation catalyst has long service life.

6. Provides technical support for the high added value utilization of waste plastic pyrolysis oil, and has very wide application prospect.

Drawings

FIG. 1 is a flow chart of a waste plastic pyrolysis oil hydrogenation purification process according to the invention;

In the figure: 1-hydrogenation catalyst, 2-hydrogen, 3-waste plastic pyrolysis oil, 4-slurry bed hydrogenation reactor, 5-hydrogenation pretreatment product, 6-gas-liquid-solid cyclone separator, 7-separation slag, 8-circulation slag, 9-externally discharged slag, 10-gas-liquid product, 11-gas-liquid separator, 12-gas product, 13-liquid product, 14-liquid-solid separator, 15-solid residue, 16-liquid product, 17-fixed bed hydrogenation reactor and 18-waste plastic pyrolysis oil after hydrogenation purification.

Detailed Description

The method for purifying the waste plastic pyrolysis oil by hydrogenation is further described below with reference to the accompanying drawings. Many devices such as pumps, heat exchangers, compressors, etc. are omitted from the figures, but are well known to those of ordinary skill in the art.

As shown in the attached figure 1, the method for the hydrogenation purification of the waste plastic pyrolysis oil has the following detailed flow:

The hydrogen 2 and the waste plastic pyrolysis oil 3 from the pipeline are respectively preheated and then are mixed with the hydrogenation catalyst 1 from the pipeline, and then enter a slurry bed hydrogenation reactor 4 for the hydrogenation pretreatment of the waste plastic pyrolysis oil, wherein the preheating temperature of the hydrogen is 350-500 ℃, the preheating temperature of the waste plastic pyrolysis oil is 150-300 ℃, the hydrogen partial pressure in the reactor is 6-15 MPa, the reaction temperature is 330-410 ℃, the liquid hourly space velocity is 0.5-2 h ^-1, and the volume ratio of the hydrogen to the waste plastic pyrolysis oil is 400-1200 Nm ³/m³; realizing the high-efficiency removal of chlorine, silicon, metal and conjugated diene in the plastic pyrolysis oil; the hydrogenation pretreatment product 5 enters a gas-liquid-solid cyclone separator 6, and separated material slag 7 is obtained after separation, wherein the separated material slag comprises circulating tailings 8 and externally discharged tailings 9, and the circulating tailings 8 circularly enter a slurry bed hydrogenation reactor 4; the gas-liquid product 10 is separated into a gas product 12 and a liquid product 13 by a gas-liquid separator 11; the liquid phase product 13 is separated by a liquid-solid separator 14 to obtain solid residue 15 which is discharged outside, the liquid product 16 enters a fixed bed hydrogenation reactor 17 for hydrofining, wherein the hydrogen partial pressure in the reactor is 6-15 MPa, the reaction temperature is 300-380 ℃, the liquid hourly space velocity is 0.5-2 h ^-1, and the volume ratio of hydrogen to the liquid product separated by the liquid-solid separator is 300-800 Nm ³/m³; further removing trace chlorine, silicon, metal and conjugated diene to finally obtain the waste plastic pyrolysis oil 18 after hydrogenation purification.

The following examples further illustrate the process for the hydrodeoxygenation of waste plastic pyrolysis oil according to the present invention, but are not intended to limit the invention thereto.

The properties of the raw materials used in the examples are shown in Table 1.

TABLE 1 main Properties of waste Plastic pyrolysis oil feedstock

Example 1

The preparation method of the hydrogenation catalyst in the waste plastic pyrolysis oil hydrogenation purification method is adopted, wherein: the powder comprises the following raw material components in parts by weight: 26% by weight of silica and 74% by weight of alumina; the raw material components of the adhesive comprise the following components in parts by weight: 23 wt% of silica sol, 67 wt% of aluminum sol, 600 wt% of polyethylene glycol PEG and 5 wt% of methylcellulose, and the mass of the adhesive accounts for 10% of the mass of the powder. The preparation method comprises the following specific steps: (1) Fully mixing and stirring aluminum hydroxide dry rubber powder and silicon dioxide powder, and kneading into a uniform powder mixture; (2) Fully contacting the prepared powder mixture with sprayed adhesive and water, and preparing spherical shaped objects by adopting a spray granulation mode; (3) Roasting the spherical shaped object in air atmosphere to obtain a spherical catalyst carrier, wherein the roasting temperature is 500 ℃ and the roasting time is 3 hours; (4) Preparing cobalt acetate and ammonium molybdate into a solution with a required concentration, impregnating the prepared spherical catalyst carrier by adopting an equal volume impregnation method, drying for 2 hours at 110 ℃, and roasting for 2 hours at 500 ℃ to prepare the hydrogenation catalyst. The hydrogenation catalyst particle size was 100 μm. The hydrogenation catalyst comprises the following components: 20% of silicon oxide, 55% of aluminum oxide, 3% of cobalt oxide and 22% of molybdenum oxide. The prepared oxidation catalyst adopts an 'out-of-device' sulfuration mode to complete the presulfiding of the catalyst. The reaction conditions of the slurry bed hydrogenation reactor are shown in Table 2, and the reaction results of the slurry bed hydrogenation reactor are shown in Table 3.

Example 2

The preparation method of the hydrogenation catalyst in the waste plastic pyrolysis oil hydrogenation purification method is adopted, wherein: the powder comprises the following raw material components in parts by weight: 26% by weight of silica and 74% by weight of alumina; the raw material components of the adhesive comprise the following components in parts by weight: 23 wt% of silica sol, 67 wt% of aluminum sol, 600 wt% of polyethylene glycol PEG and 5 wt% of methylcellulose, and the mass of the adhesive accounts for 10% of the mass of the powder. The preparation method comprises the following specific steps: (1) Fully mixing and stirring aluminum hydroxide dry rubber powder and silicon dioxide powder, and kneading into a uniform powder mixture; (2) Fully contacting the prepared powder mixture with sprayed adhesive and water, and preparing spherical shaped objects by adopting a spray granulation mode; (3) Roasting the spherical shaped object in air atmosphere to obtain a spherical catalyst carrier, wherein the roasting temperature is 500 ℃ and the roasting time is 3 hours; (4) Preparing nickel nitrate and ammonium molybdate into a solution with a required concentration, impregnating the prepared spherical catalyst carrier by adopting an equal volume impregnation method, drying for 2 hours at 110 ℃, and roasting for 2 hours at 500 ℃ to prepare the hydrogenation catalyst. The hydrogenation catalyst comprises the following components: 20% of silicon oxide, 55% of aluminum oxide, 3% of nickel oxide and 22% of molybdenum oxide. The prepared oxidation catalyst adopts an 'out-of-device' sulfuration mode to complete the presulfiding of the catalyst. The reaction conditions of the slurry bed hydrogenation reactor are shown in Table 2, and the reaction results of the slurry bed hydrogenation reactor are shown in Table 3.

Example 3

The preparation method of the hydrogenation catalyst in the waste plastic pyrolysis oil hydrogenation purification method is adopted, wherein: the powder comprises the following raw material components in parts by weight: 26% by weight of silica and 74% by weight of alumina; the raw material components of the adhesive comprise the following components in parts by weight: 23 wt% of silica sol, 67 wt% of aluminum sol, 600 wt% of polyethylene glycol PEG and 5 wt% of methylcellulose, and the mass of the adhesive accounts for 10% of the mass of the powder. The preparation method comprises the following specific steps: (1) Fully mixing and stirring aluminum hydroxide dry rubber powder and silicon dioxide powder, and kneading into a uniform powder mixture; (2) Fully contacting the prepared powder mixture with sprayed adhesive and water, and preparing spherical shaped objects by adopting a spray granulation mode; (3) Roasting the spherical shaped object in air atmosphere to obtain a spherical catalyst carrier, wherein the roasting temperature is 500 ℃ and the roasting time is 3 hours; (4) Preparing nickel nitrate and ammonium metatungstate into a solution with a required concentration, impregnating the prepared spherical catalyst carrier by adopting an equal volume impregnation method, drying for 2 hours at 110 ℃, and roasting for 2 hours at 500 ℃ to prepare the hydrogenation catalyst. The hydrogenation catalyst particle size was 100 μm. The hydrogenation catalyst comprises the following components: 20% of silicon oxide, 55% of aluminum oxide, 3% of nickel oxide and 22% of tungsten oxide. The prepared oxidation catalyst adopts an 'out-of-device' sulfuration mode to complete the presulfiding of the catalyst. The reaction conditions of the slurry bed hydrogenation reactor are shown in Table 2, and the reaction results of the slurry bed hydrogenation reactor are shown in Table 3.

Example 4

The adopted hydrogenation catalyst is waste agent of industrial diesel hydrofining catalyst, and the composition of the waste agent is as follows: 72 wt% of aluminum oxide, 4 wt% of nickel oxide and 24 wt% of molybdenum oxide. The catalyst particle size was 100. Mu.m. The reaction conditions of the slurry bed hydrogenation reactor are shown in Table 2, and the reaction results of the slurry bed hydrogenation reactor are shown in Table 3.

TABLE 2 hydrogenation reaction conditions for waste Plastic pyrolysis oil slurry bed

TABLE 3 results of waste Plastic pyrolysis oil slurry bed hydrogenation reaction

As shown in the results of Table 3, the slurry bed hydrogenation pretreatment process adopted by the method of the invention for waste plastic pyrolysis oil can obtain pretreated products with chlorine and silicon content less than 10ppm, the metal content is reduced from 200 mg/kg to about 10 mg/kg, the iodine value is reduced from 16.67/g/100 g to less than 1g/100g, and the efficient removal of chlorine, silicon, metal and conjugated diene in the inferior plastic pyrolysis oil is realized.

Example 5

The liquid product obtained in the above example 2 is fed into a fixed bed hydrogenation reactor for hydrofining, wherein the hydrofining catalyst can be selected from common commercial catalysts in the field. This example uses hydrofining catalyst FGP-302 developed by heavy oil national emphasis laboratories. The hydrofining reaction conditions of the fixed bed hydrogenation reactor are as follows: the hydrogen partial pressure in the reactor was 8MPa, the reaction temperature was 340 ℃, the liquid hourly space velocity was 1.5h ^-1, the hydrogen volume ratio was 600Nm ³/m³, and the reaction results are shown in Table 4.

TABLE 4 deep hydrogenation reaction results of waste Plastic pyrolysis oil

As shown in the results of Table 4, the waste plastic pyrolysis oil adopts a slurry bed hydrogenation pretreatment and fixed bed hydrofining combined process according to the method of the invention, and the chlorine and silicon content in the obtained purified product is less than 1ppm, thereby realizing the deep hydrogenation purification of the inferior plastic pyrolysis oil.

It will be apparent to those skilled in the art that the present invention has been described in detail by way of illustration only, and it is not intended to be limited by the above-described embodiments, as long as various insubstantial modifications of the method concepts and aspects of the invention are employed or the inventive concepts and aspects of the invention are directly applied to other applications without modification, all within the scope of the invention.

Claims

1. The waste plastic pyrolysis oil hydrogenation purification method is characterized by comprising the following steps:

S105: obtaining waste plastic pyrolysis oil after hydrogenation purification after the hydrofining reaction;

The waste plastic pyrolysis oil, hydrogen and a hydrogenation catalyst in the S101 are mixed and then enter a slurry bed hydrogenation reactor from the bottom, and flow from bottom to top; the slurry bed hydrogenation reactor has the following reaction conditions: the hydrogen partial pressure in the reactor is 6-15 MPa, the reaction temperature is 330-410 ℃, the liquid hourly space velocity is 0.5-2 h ^-1, and the volume ratio of hydrogen to waste plastic pyrolysis oil is 400-1200 Nm ³/m³;

The addition amount of the hydrogenation catalyst in the S101 accounts for 0.005-0.2 wt% of the waste plastic pyrolysis oil;

The hydrogenation catalyst in the S101 comprises the following components: 1 to 6 weight percent of nickel oxide and/or cobalt oxide, 6 to 24 weight percent of molybdenum oxide and/or tungsten oxide, and the balance of silicon oxide-aluminum oxide; silica-alumina: the silica content is 10 to 40 wt% and the alumina content is 60 to 90 wt% based on the carrier.

2. The method for the hydrogenation purification of the waste plastic pyrolysis oil according to claim 1, wherein the temperature after the hydrogen gas is preheated in the S101 is 350-500 ℃, and the temperature after the waste plastic pyrolysis oil is preheated is 150-300 ℃; the operation conditions of the gas-liquid-solid cyclone separator in the step S102 are as follows: the pressure is 6-15 MPa, and the temperature is 200-300 ℃; and S102, separating the obtained tailings by a gas-liquid-solid cyclone separator, wherein the amount of the tailings recycled to the inlet of the slurry bed hydrogenation reactor accounts for 80% -98% of the total amount of the tailings, and the external discharge amount accounts for 2% -20% of the total amount of the tailings.

3. The method for the hydrogenation purification of waste plastic pyrolysis oil according to claim 1, wherein the reaction conditions of the fixed bed hydrogenation reactor in S104 are as follows: the hydrogen partial pressure in the reactor is 6-15 MPa, the reaction temperature is 300-380 ℃, the liquid hourly space velocity is 0.5-2 h ^-1, and the volume ratio of the hydrogen to the liquid product separated by the liquid-solid separator is 300-800 Nm ³/m³.

4. The method for the hydrogenation purification of waste plastic pyrolysis oil according to claim 1, wherein the preparation step of the hydrogenation catalyst in S101 is as follows:

5. The method for the hydrogenation purification of waste plastic pyrolysis oil according to claim 4, wherein the hydrogenation catalyst is spherical and has an outer diameter of 50-500 μm.

6. The method for the hydrodeoxygenation of waste plastic pyrolysis oil according to claim 1, wherein the waste plastic pyrolysis oil comprises liquid oil prepared by anaerobic pyrolysis, hydropyrolysis or catalytic pyrolysis of various waste plastic products, waste tires and rubber; the waste plastic pyrolysis oil hydrogenation purification method is also suitable for the hydrogenation purification treatment of waste lubricating oil.