Chlorine-containing pyrolysis oil radial moving bed reaction adsorption dechlorination hydro-conversion method

Abstract

The invention discloses a chlorine-containing pyrolysis oil radial moving bed reaction adsorption dechlorination hydro-conversion method, and belongs to the technical field of chlorine-containing oil product hydrotreatment and refining. According to the method, chlorine-containing pyrolytic oil is sequentially subjected to fixed bed selective hydrogenation, radial moving bed reaction adsorption dechlorination and fixed bed deep hydrofining reactor treatment; the radial moving bed is filled with a core-shell structure reaction and adsorption integrated catalyst, the core is a hydrodechlorination active component, the shell mainly adopts zinc oxide to adsorb HCl and is fixed in situ, and meanwhile, online addition and discharge of the catalyst are realized through the radial moving bed. According to the invention, poisoning of chlorine to the catalyst is effectively inhibited, the corrosion risk of equipment is reduced, shutdown of the device is avoided, the dechlorination efficiency is improved, the continuous operation period is prolonged, efficient, stable and economical hydro-conversion of the chlorine-containing pyrolytic oil is realized, and the obtained product can be used as clean fuel oil or a chemical raw material.

Description

Technical Field

[0001] This invention relates to the field of hydrotreating and refining technology for chlorinated oils, specifically to a radial moving bed reactive adsorption dechlorination and hydroconversion method for chlorinated pyrolysis oils. Background Technology

[0002] Chlorinated pyrolysis oil, an important liquid product generated in recent years from the pyrolysis of waste plastics, waste tires, and other chlorinated organic solids, possesses potential value as fuel and chemical feedstock. It also plays a crucial role in solid waste reduction, resource recovery, and harmless treatment, significantly contributing to the construction of a resource recycling system. However, this type of pyrolysis oil typically contains various forms of organochlorides and may also contain inorganic chloride salts formed during pyrolysis. Traditional hydrogenation processes often employ fixed-bed reactors, using hydrodechlorination catalysts to achieve the hydrogenolysis of chlorinated compounds, releasing chlorine as hydrogen chloride (HCl) or chloride ions (Cl-). However, in actual operation, chlorides readily adsorb strongly onto the active metal sites of the catalyst, leading to rapid catalyst deactivation within a short time. Furthermore, chlorides can cause equipment corrosion, further deteriorating the overall safety and stability of the process. Therefore, the efficient and stable removal of chlorine from chlorinated pyrolysis oil is a key technological bottleneck limiting the industrial utilization of this resource.

[0003] To mitigate the poisoning of hydrogenation catalysts by chlorine, existing processes often maintain unit operation by increasing the hydrogen-to-oil ratio, raising operating temperature or pressure, using catalysts with higher metal loading and stronger activity, or even shortening catalyst lifespan. However, these measures significantly increase energy consumption and operating costs, and still cannot fundamentally curb the rapid deactivation caused by chlorine accumulation. There have also been attempts to develop modified catalysts with certain chlorine resistance by improving metal dispersion or modulating the interaction between the metal and the support to enhance chlorine resistance. However, the preparation of such catalysts is complex and costly, and their stability is limited under actual operating conditions with large fluctuations in feed chlorine content. On the other hand, solutions that reduce feed chlorine content by adding physical or chemical dechlorination units at the upstream end generally suffer from complex processes, high equipment investment and operating costs, and dechlorination efficiency that is greatly affected by feed properties and operating conditions. Furthermore, traditional fixed-bed reactors lack flexibility; once the catalyst deactivates due to excessive chlorine adsorption, it often requires shutdown and catalyst replacement, leading to production interruptions, reduced material handling capacity, and decreased overall economic efficiency. For systems with highly fluctuating feedstocks and complex impurities, such as chlorinated pyrolysis oil, fixed beds struggle to address the issue of catalyst activity decay over time and find it difficult to buffer feed quality changes by adjusting bed composition online. Currently available technologies lack a comprehensive solution that can effectively control chlorine poisoning of the catalyst during hydroconversion while maintaining process simplicity, continuous operation, and long-term stable performance.

[0004] Therefore, based on the need for clean and recyclable chlorine-containing pyrolysis oil, it is necessary to develop new hydroconversion processes and reactor types that, while ensuring the reaction system has excellent dechlorination capabilities and catalyst chlorine resistance, also have the ability to adjust the catalyst online, so as to improve the adaptability of the unit to feedstock fluctuations and chlorine accumulation, and realize the efficient, stable and economical industrial utilization of chlorine-containing pyrolysis oil. Summary of the Invention

[0005] Based on previous research and existing problems, this invention proposes a radial moving bed reactive adsorption dechlorination and hydrogenation conversion method for chlorinated pyrolysis oil. This method employs a novel radial moving bed reactive adsorption dechlorination reactor and a dedicated core-shell type reactive adsorption dechlorination agent. This allows for in-situ retention of chlorine after hydrogenation of chlorinated compounds, maximizing the avoidance of chlorine poisoning of hydrogenated metals. Simultaneously, the radial moving bed process enables online addition and removal of the catalyst, avoiding the short operating cycle caused by adsorbent saturation and deactivation.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A radial moving bed reactive adsorption dechlorination and hydrogenation conversion method for chlorine-containing pyrolysis oil, targeting chlorine-containing pyrolysis oil or other chlorine-containing oil products generated from the pyrolysis of waste plastics and waste tires, involves the following steps: S1. The chlorine-containing pyrolysis oil is fed into a fixed-bed selective hydrogenation reactor to selectively hydrogenate the olefins and / or dienes in the feedstock in the presence of hydrogen. S2. The product obtained in step S1 is fed into a radially moving bed reaction adsorption dechlorination reactor. Hydrodechlorination reaction is carried out in the presence of a core-shell structure reaction adsorption integrated hydrodechlorination catalyst. The HCl generated in the reaction is adsorbed and fixed in situ by the outer shell adsorption layer of the catalyst during the diffusion process. The stream enters from the bottom of the reactor, is diverted by the baffle, and passes radially through the catalyst bed. The catalyst is added from the top of the reactor and moves downward under the action of gravity to contact the stream in the countercurrent. At the same time, the catalyst is replenished and discharged online through the radially moving bed method. The deactivated or adsorbed saturated catalyst is discharged from the bottom of the reactor. S3. The product obtained in step S2 is fed into a fixed-bed deep hydrorefining reactor for deep desulfurization, denitrification and aromatic saturation deep hydrorefining to obtain clean fuel oil or chemical raw materials.

[0007] Preferably, the reaction conditions of the fixed-bed selective hydrogenation reactor in step S1 are: reaction temperature 60–180°C, hydrogen partial pressure 4–12 MPa, and liquid hourly space velocity 0.5–2 h⁻¹. -1 The volume ratio of hydrogen to liquid feedstock is 100–1000 Nm³. 3 / m 3 .

[0008] Preferably, the catalysts packed in the fixed-bed selective hydrogenation reactor and the fixed-bed deep hydrogenation refining reactor are inorganic refractory oxide supports loaded with active metal sulfides. The metals of the active metal sulfides are selected from Group VIB and / or Group VIII metals, and the inorganic refractory oxide supports are selected from one or more of alumina, silica, amorphous aluminosilicate, and titanium dioxide.

[0009] Preferably, the metal of the active metal sulfide is selected from one or more of tungsten, molybdenum, nickel, and cobalt, and the content of tungsten and / or molybdenum is 10% to 50% and the content of nickel and / or cobalt is 1% to 15% by weight percentage of the metal oxide.

[0010] Preferably, the hydrodechlorination reaction conditions in the radial moving bed reactive adsorption dechlorination reactor in step S2 are: reaction temperature 220–340°C, hydrogen partial pressure 4–12 MPa, and liquid hourly space velocity 0.5–2 h⁻¹. -1 The volume ratio of hydrogen to liquid feedstock is 100–1000 Nm³. 3 / m 3 .

[0011] Preferably, the core-shell structured integrated hydrodechlorination catalyst includes a core and an outer shell adsorption layer covering the outer surface of the core. The core is a support loaded with hydrodechlorination active metal components, and the outer shell adsorption layer uses zinc oxide as the main adsorption component and is supplemented with structural stabilizing components to achieve near-source capture and fixation of chlorinated organic compounds and the generation of HCl at the single particle scale.

[0012] Preferably, in the core of the core-shell structured integrated hydrodechlorination catalyst, the active metal component for hydrodechlorination is selected from one or more of nickel, molybdenum, tungsten, and cobalt, and the total content of the active metal component for hydrodechlorination in the core is 0.5 to 30 wt% based on metal oxides; the support for the core is selected from alumina, silica, zirconium oxide, molecular sieves or composite supports thereof.

[0013] Preferably, in the outer shell adsorption layer of the core-shell structured reactive adsorption integrated hydrodechlorination catalyst, the zinc oxide content is 70-95 wt%, and the structural stabilizing component is selected from one or more of alumina, silicon dioxide, and zirconium oxide, with a content of 5-30 wt%.

[0014] Preferably, the reaction conditions for the fixed-bed deep hydrorefining reactor are: reaction temperature 320–380℃, hydrogen partial pressure 4–12 MPa, and liquid hourly space velocity 0.5–2 h⁻¹. -1 The volume ratio of hydrogen to liquid feedstock is 100–1000 Nm³. 3 / m 3 .

[0015] Preferably, the deep hydrorefined product obtained in step S3 is subjected to gas-liquid separation, stripping, and three-phase separation to obtain naphtha fraction and clean pyrolysis oil. The separated circulating hydrogen is returned to the fixed-bed selective hydrorefining reactor for recycling.

[0016] Compared with the prior art, the present invention provides a radial moving bed reactive adsorption dechlorination and hydrogenation conversion method for chlorine-containing pyrolysis oil, which has the following beneficial effects: (1) This invention constructs a spherical shell structure reaction-adsorption integrated catalyst by coupling a core hydrodechlorination active layer and an outer shell adsorption layer, thereby achieving the hydrodechlorination reaction of chlorinated organic compounds and the near-source capture and fixation of HCl at the single-particle scale. Chlorinated organic compounds undergo hydrodechlorination in the core to generate HCl. The generated HCl is adsorbed by the outer shell adsorption layer and fixed in the solid phase structure during its outward diffusion process, thereby effectively inhibiting the migration of chlorinated species in the reaction phase and bed, reducing the probability of their contact with the active metal center of hydrodechlorination, slowing down the catalyst activity decay caused by chlorine poisoning, and extending the service life.

[0017] (2) The present invention adopts a radial moving bed reactive adsorption dechlorination reactor and is combined with online catalyst addition and discharge: On the one hand, the reactive adsorption dechlorination catalyst can be continuously replenished and discharged, avoiding the problem of having to stop and replace it due to adsorbent saturation or catalyst deactivation, so that the dechlorination and hydrogenation unit and the whole process can achieve continuous and long-term stable operation; On the other hand, after the pyrolysis oil enters the reactor, it flows radially through the bed through the baffle, which can significantly reduce the bed pressure drop and improve the uniformity of the flow field distribution, thereby reducing the risk of local blockage / coking and local hot spots, and improving the bed heat and mass transfer and the safety of the device operation.

[0018] (3) The present invention enables chlorine to be adsorbed and fixed in situ in solid form during hydrogenation conversion through reaction adsorption dechlorination, thereby reducing the free and migration of corrosive chlorine-containing components such as HCl in the reaction system and material stream, thereby reducing the corrosion risk of the reactor and downstream heat exchange, separation and other equipment, and improving the safety and reliability of the equipment operation.

[0019] (4) The present invention can effectively reduce the chlorine content in the product oil, improve the quality of the hydroconversion products, and make the obtained oil more suitable for use as fuel or chemical raw material, thereby enhancing the resource utilization value of chlorine-containing pyrolysis oil and promoting the clean, efficient and economical utilization of solid waste such as waste plastics and waste tires. Attached Figure Description

[0020] Figure 1 This is a process flow diagram of a radial moving bed reactive adsorption dechlorination and hydrogenation conversion method for chlorine-containing pyrolysis oil according to the present invention.

[0021] In the diagram: 1. Chlorinated pyrolysis oil; 2. Heating furnace; 3. Fresh hydrogen; 4. Fixed-bed selective hydrogenation reactor; 5. Pyrolysis oil after selective hydrogenation; 6. Radial moving bed reactive adsorption dechlorination reactor; 7. Fresh reactive adsorption dechlorination catalyst; 8. Deactivated reactive adsorption dechlorination catalyst; 9. Pyrolysis oil after dechlorination; 10. Fixed-bed deep hydrogenation reactor; 11. Products after deep hydrogenation; 12. Separator; 13. Circulating hydrogen; 14. Circulating hydrogen compressor; 15. Separator liquid products; 16. Stripping tower; 17. Stripping tower condenser; 18. Three-phase separator; 19. Non-condensable gas; 20. Water; 21. Naphtha fraction; 22. Circulating naphtha fraction; 23. Clean pyrolysis oil. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] like Figure 1 As shown, the method of the present invention includes three stages connected in series: a fixed-bed selective hydrogenation reaction, a radially moving-bed reactive adsorption dechlorination hydrogenation reaction, and a fixed-bed deep hydrogenation purification reaction, and is equipped with separation, hydrogen recycling, and gas stripping units.

[0024] 1. Fixed-bed selective hydrogenation reaction Chlorine-containing pyrolysis oil 1 is heated in heater 2 and then mixed with fresh hydrogen 3 and recycled hydrogen 13 before entering a fixed-bed selective hydrogenation reactor 4. This process selectively hydrogenates and removes olefins and / or dienes from the feedstock to improve the stability of subsequent reactions. The reaction conditions are: hydrogen partial pressure in the reactor 4–12 MPa, reaction temperature 60–180 °C, and liquid hourly space velocity 0.5–2 h⁻¹. -1 The volume ratio of hydrogen to liquid feedstock is 100–1000 Nm³. 3 / m 3 The resulting product is selectively hydrogenated and then pyrolyzed to produce oil 5, which enters the next stage.

[0025] The catalyst packed in the fixed-bed selective hydrogenation reactor 4 includes a support and its supported active metal sulfide; the support is an inorganic refractory oxide, selected from one or more of alumina, silica, amorphous silica-alumina, and titanium dioxide; the metal in the active metal sulfide is selected from Group VIB and / or Group VIII metal components, preferably one or more of tungsten, molybdenum, nickel, and cobalt; based on the weight percentage of the corresponding metal oxide, tungsten and / or molybdenum is 10% to 50% (preferably 15% to 35%), and nickel and / or cobalt is 1% to 15% (preferably 3% to 10%). Commercially available hydrogenation catalysts can also be used for selective hydrogenation.

[0026] 2. Radial moving bed reactive adsorption dechlorination and hydrogenation reaction After selective hydrogenation, the pyrolysis oil 5 enters the radially moving bed reactive adsorption dechlorination reactor 6, where the hydrogenation of chlorine-containing compounds and the in-situ fixation of chlorine-containing species are achieved under hydrogenation conditions. The reaction conditions are: hydrogen partial pressure in the reactor 4–12 MPa, reaction temperature 220–340 °C, and liquid hourly space velocity 0.5–2 h⁻¹. -1 The volume ratio of hydrogen to liquid feedstock is 100–1000 Nm³. 3 / m 3 .

[0027] After selective hydrotreating, the pyrolysis oil 5 enters from the bottom of the radially moving bed reactive adsorption dechlorination reactor 6, flows radially after being deflected, and is finally discharged from the top. Fresh reactive adsorption dechlorination catalyst 7 is continuously or intermittently added from the top of the radially moving bed reactive adsorption dechlorination reactor 6, moves axially downwards, and is partially discharged (either deactivated or saturated) at the bottom of the reactor via a discharge device. The two reactants form a countercurrent contact within the reactor 6, allowing the dechlorination reaction and in-situ adsorption of hydrogen chloride to be completed simultaneously during the reaction process. This enables online catalyst renewal and avoids the problem of shortened operating cycles due to adsorbent saturation and deactivation.

[0028] The fresh reactive adsorption dechlorination catalyst 7 is a spherical-shell structured reactive adsorption catalyst with a coupled core hydrodechlorination active layer and an outer adsorption layer. It achieves simultaneous capture and fixation of HCl generated from the hydrodechlorination of chlorine-containing compounds at the single-particle scale. The catalyst comprises a core and an outer adsorption layer covering the outer surface of the core. The core contains a hydrodechlorination active metal component supported on a carrier, while the outer adsorption layer is used for near-source adsorption and fixation of the HCl generated in the core reaction.

[0029] The core carrier is an inorganic refractory oxide, selected from alumina, silica, molecular sieves, or composite carriers thereof; the hydrodechlorination active metal component is selected from one or more of nickel, molybdenum, tungsten, and cobalt, with nickel as the main active metal and molybdenum and / or tungsten may be further introduced to form a bimetallic system. The total content of the hydrodechlorination active metal component in the core, calculated as oxide, is 0.5%–30%. The outer shell adsorbent layer comprises an adsorbent component and a structural stabilizing component. The adsorbent component is mainly zinc oxide, used to adsorb and fix HCl generated in the hydrodechlorination reaction. The structural stabilizing component is selected from one or more of alumina, silica, or zirconium oxide, used to improve the mechanical strength and thermal stability of the outer shell adsorbent layer. The content of the adsorbent component in the outer shell adsorbent layer is 70%–95%, and the content of the structural stabilizing component is 5%–30%.

[0030] The spherical shell structure reaction-adsorption integrated catalyst is prepared by rolling molding, so that the outer shell adsorbent layer is continuously coated on the outer surface of the core, thereby constructing a controlled mass transfer pathway of "reaction first, capture later" inside a single particle.

[0031] The dechlorinated pyrolysis oil 9, after undergoing radial moving bed reactive adsorption dechlorination treatment, is drawn out and enters the next stage.

[0032] 3. Fixed-bed deep hydrogenation refining reaction After dechlorination, the pyrolysis oil 9 enters the fixed-bed deep hydrorefining reactor 10 for deep desulfurization, denitrification, and aromatic saturation reactions. The reaction conditions are: hydrogen partial pressure in the reactor 4–12 MPa, reaction temperature 320–380 °C, and liquid hourly space velocity 0.5–2 h⁻¹. -1 The volume ratio of hydrogen to liquid feedstock is 100–1000 Nm³. 3 / m 3 The catalyst packed in the deep hydrorefining reactor 10 includes a support and its supported active metal sulfide, and its composition is the same as that of the catalyst used in the fixed-bed selective hydrorefining reactor 4, or a commercially available deep hydrorefining catalyst is used.

[0033] 4. Product separation and stripping recovery After deep hydrogenation, product 11 enters separator 12 for gas-liquid separation. Separator 12 may include a conventional combination of high-pressure and low-pressure separators. The gaseous product at the top of the separator is circulating hydrogen 13, which is compressed by circulating hydrogen compressor 14 and returned to fixed-bed selective hydrogenation reactor 4 for use; the liquid product 15 from the separator enters stripper 16 for gas stripping. The product at the top of the stripper is condensed by condenser 17 and enters three-phase separator 18 to obtain non-condensable gas 19, water 20, and naphtha fraction 21. A portion of the naphtha fraction is used as a reflux system for circulating naphtha fraction 22, and the remainder is output as product; the bottom of the stripper yields clean pyrolysis oil 23, which can be further used as fuel oil or chemical feedstock.

[0034] The following embodiments will further illustrate the method provided by the present invention, but do not limit the present invention.

[0035] The raw materials used in the examples and comparative examples are two pyrolysis oils with different chlorine contents, and their main properties are shown in Table 1.

[0036] Table 1 Properties of Chlorine-Containing Pyrolysis Oils In the examples and comparative examples, the same catalyst, commercially known as FDS-1, was used for both the selective hydrogenation and deep hydrogenation stages.

[0037] All embodiments adopt Figure 1 The process is shown below.

[0038] Example 1 In this embodiment, chlorinated pyrolysis oil 1 is used as raw material, and catalyst A is packed in the radial moving bed reactive adsorption dechlorination reactor 6. The preparation process is as follows: S1. Preparation of catalyst core powder: Weigh an alumina support and prepare a mixed aqueous solution containing nickel nitrate and ammonium molybdate tetrahydrate as an impregnation solution, wherein the total content of Ni in the core is 3 wt% (based on oxides) and the total content of Mo in the core is 15 wt% (based on oxides). Impregnate the support with the impregnation solution using an equal-volume impregnation method, and let it stand for 6 h after impregnation. Then, dry the impregnated sample at 110 ℃ for 10 h and calcine it at 550 ℃ for 6 h in air atmosphere to obtain an active metal supported catalyst powder.

[0039] The powder was added to a pelletizing machine and rolled into a catalyst core with an average particle size of 1 mm under the condition of atomized spraying of aluminum sol and nitric acid aqueous solution (volume ratio 15:1).

[0040] S2. Preparation of catalyst shell powder: Weigh basic zinc carbonate and boehmite according to the mass ratio, wherein basic zinc carbonate accounts for 90 wt% and boehmite accounts for 10 wt%. Add the two to a mixer for wet mixing, add an appropriate amount of deionized water, and mix thoroughly under stirring conditions to form a uniform precursor mixture.

[0041] The mixture was dried at 110 °C for 12 h, and then calcined in air at 550 °C for 6 h to decompose the precursor and form a porous ZnO–Al2O3 composite oxide. The calcined product was then pulverized and sieved to obtain a catalyst shell powder with a particle size suitable for roll forming.

[0042] S3. Forming of the core-shell catalyst: The catalyst core and shell powder prepared above are added together into a pelletizing machine and rolled into shape under the condition of atomized adhesive spraying, so that the shell powder continuously coats the outer surface of the core (average shell thickness 1 mm). The formed particles are dried at 110 ℃ for 10 h and calcined at 550 ℃ for 6 h to obtain core-shell integrated reaction-adsorption catalyst A.

[0043] In this embodiment, the specific reaction conditions and reaction results are shown in Tables 2 and 3, respectively.

[0044] Example 2 In this embodiment, chlorinated pyrolysis oil 1 is used as raw material, and catalyst B is packed in the radial moving bed reactive adsorption dechlorination reactor 6. The preparation process is as follows: S1. Preparation of catalyst core powder: Weigh the silica support and prepare a mixed aqueous solution containing nickel nitrate and ammonium metatungstate as the impregnation solution, wherein the total content of Ni in the core is 3 wt% (based on oxides) and the total content of W in the core is 17 wt% (based on oxides). Impregnate the support with the impregnation solution using an equal-volume impregnation method, and let it stand for 6 h after impregnation. Then, dry the impregnated sample at 110 ℃ for 10 h and calcine it at 550 ℃ for 6 h in air atmosphere to obtain an active metal supported catalyst powder.

[0045] The powder was added to a pelletizer and rolled into a catalyst core with an average particle size of 1 mm under the condition of atomized spraying of aluminum sol and nitric acid aqueous solution (volume ratio 15:1).

[0046] S2. Preparation of catalyst shell powder: Weigh basic zinc carbonate, silica sol, and zirconium hydroxide according to the following mass ratio, wherein basic zinc carbonate accounts for 90 wt%, silica sol accounts for 5 wt%, and zirconium hydroxide accounts for 5 wt%. Add both to a mixer for wet mixing, add an appropriate amount of deionized water, and mix thoroughly under stirring conditions to form a uniform precursor mixture.

[0047] The mixture was dried at 110 °C for 12 h, and then calcined in air at 550 °C for 6 h to decompose the precursor and form a porous ZnO–SiO2-ZrO2 composite oxide. The calcined product was then pulverized and sieved to obtain a catalyst shell powder with a particle size suitable for roll forming.

[0048] S3. Forming of the core-shell catalyst: The catalyst core and shell powder prepared above are added together into a pelletizing machine and rolled under the condition of atomized adhesive spraying, so that the shell powder continuously coats the outer surface of the core (average shell thickness 1 mm). The formed particles are dried at 110 ℃ for 10 h and calcined at 550 ℃ for 6 h to obtain core-shell type reaction-adsorption integrated catalyst B.

[0049] In this embodiment, the specific reaction conditions and reaction results are shown in Tables 2 and 3, respectively.

[0050] Example 3 In this embodiment, chlorinated pyrolysis oil 2 is used as raw material, and catalyst A is packed in the radial moving bed reactive adsorption dechlorination reactor 6. The preparation process is consistent with that in Example 1.

[0051] In this embodiment, the specific reaction conditions and reaction results are shown in Tables 2 and 3, respectively.

[0052] Example 4 In this embodiment, chlorinated pyrolysis oil 2 is used as raw material, and catalyst B is packed in the radial moving bed reactive adsorption dechlorination reactor 6. The preparation process is consistent with that in Example 2.

[0053] In this embodiment, the specific reaction conditions and reaction results are shown in Tables 2 and 3, respectively.

[0054] Comparative Example 1 The process flow of Comparative Example 1 is basically the same as that of the Example, and the raw material used is chlorinated pyrolysis oil 2. The difference is that the radial moving bed reactive adsorption dechlorination reactor 6 is replaced with a conventional moving bed reactor.

[0055] Comparative Example 2 Comparative Example 2 follows a process flow that is basically the same as the Example, using chlorinated pyrolysis oil 2 as the raw material. The difference is that the radial moving bed reactive adsorption dechlorination reactor 6 is replaced with a fixed bed reactor, and reactive adsorption dechlorination catalyst A is loaded into the fixed bed reactor. During the reaction, no online addition or removal of catalyst is performed (i.e., the catalyst is not updated online).

[0056] In this comparative example, the specific reaction conditions and reaction results are shown in Table 2 and Table 3, respectively.

[0057] Comparative Example 3 Comparative Example 3 follows a process flow that is essentially the same as the Example, using chlorinated pyrolysis oil 2 as the raw material. The difference lies in that the radial moving bed reactive adsorption dechlorination reactor 6 is replaced with a fixed bed reactor, and the fixed bed reactor is filled with the hydrogenation catalyst FDS-1. During the reaction, no online addition or removal of the catalyst is performed (i.e., the catalyst is not updated online).

[0058] In this comparative example, the specific reaction conditions and reaction results are shown in Table 2 and Table 3, respectively.

[0059] Table 2 Reaction conditions Table 3 Reaction Results a Deactivation is defined as a decrease of 20 wt% in any one of the desulfurization rate, denitrification rate, or dechlorination rate compared to the fresh catalyst. As shown in Table 3, the embodiments of the present invention, when using a radial moving bed reactive adsorption dechlorination structure in the second reactor and coordinating online catalyst replenishment and discharge, can achieve a deactivation cycle of >1000 h under conditions where HCl is undetectable at the outlet and the product chlorine content is 1.0–2.4 ppm. In contrast, in Comparative Example 1, when the radial moving bed reactive adsorption dechlorination reactor 6 was replaced with a conventional moving bed, the product chlorine content was 2.5 ppm and the deactivation cycle was 800 h; in Comparative Example 2, when the radial moving bed reactive adsorption dechlorination reactor 6 was replaced with a fixed bed and no online catalyst replacement was performed, the product chlorine content was 2.0 ppm and the deactivation cycle was 400 h; in Comparative Example 3, when a conventional hydrogenation catalyst FDS-1 was used in a fixed bed and no online replacement was performed, the outlet HCl content was 150 ppm, the product chlorine content increased to 5.5 ppm, and the deactivation cycle was only 50 h. This demonstrates that radial flow through a radially moving bed helps reduce bed pressure drop and improve bed flow field distribution. Simultaneously, the near-source adsorption and fixation of HCl by the core-shell catalyst, combined with the synergistic effect of online catalyst addition and removal, improves dechlorination stability and extends operating cycles. The examples show that even with longer deactivation cycles, lower product chlorine content and better HCl control levels are maintained, significantly improving unit operational stability and adaptability for continuous industrial production. Therefore, this invention provides a new and reliable engineering technology path for the continuous, long-cycle, and safe hydroconversion processing of chlorinated pyrolysis oils.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions claimed by the present invention.

Claims

1. A radial moving bed reactive adsorption dechlorination and hydrogenation conversion method for chlorinated pyrolysis oil, characterized in that, For chlorinated pyrolysis oil or other chlorinated oil products generated from the pyrolysis of waste plastics and waste tires, the following steps shall be performed in sequence: S1. The chlorine-containing pyrolysis oil is fed into a fixed-bed selective hydrogenation reactor to selectively hydrogenate the olefins and / or dienes in the feedstock in the presence of hydrogen. S2. The product obtained in step S1 is fed into a radially moving bed reaction adsorption dechlorination reactor. Hydrodechlorination reaction is carried out in the presence of a core-shell structure reaction adsorption integrated hydrodechlorination catalyst. The HCl generated in the reaction is adsorbed and fixed in situ by the outer shell adsorption layer of the catalyst during the diffusion process. The stream enters from the bottom of the reactor, is diverted by the baffle, and passes radially through the catalyst bed. The catalyst is added from the top of the reactor and moves downward under the action of gravity to contact the stream in the countercurrent. At the same time, the catalyst is replenished and discharged online through the radially moving bed method. The deactivated or adsorbed saturated catalyst is discharged from the bottom of the reactor. S3. The product obtained in step S2 is fed into a fixed-bed deep hydrorefining reactor for deep desulfurization, denitrification and aromatic saturation deep hydrorefining to obtain clean fuel oil or chemical raw materials.

2. The radial moving bed reactive adsorption dechlorination and hydrogenation conversion method for chlorinated pyrolysis oil according to claim 1, characterized in that, The reaction conditions in the fixed-bed selective hydrogenation reactor in step S1 are: reaction temperature 60–180℃, hydrogen partial pressure 4–12 MPa, and liquid hourly space velocity 0.5–2 h⁻¹. -1 The volume ratio of hydrogen to liquid feedstock is 100–1000 Nm³. 3 / m 3 .

3. The radial moving bed reactive adsorption dechlorination and hydrogenation conversion method for chlorinated pyrolysis oil according to claim 2, characterized in that, Both the fixed-bed selective hydrogenation reactor and the fixed-bed deep hydrogenation refining reactor are filled with inorganic refractory oxide supports loaded with active metal sulfides. The active metal sulfides are selected from Group VIB and / or Group VIII metals, and the inorganic refractory oxide supports are selected from one or more of alumina, silica, amorphous aluminosilicate, and titanium dioxide.

4. The radial moving bed reactive adsorption dechlorination and hydrogenation conversion method for chlorinated pyrolysis oil according to claim 3, characterized in that, The metals in the active metal sulfides are selected from one or more of tungsten, molybdenum, nickel, and cobalt. The content of tungsten and / or molybdenum is 10% to 50% and the content of nickel and / or cobalt is 1% to 15% by weight percentage of the metal oxides.

5. The radial moving bed reactive adsorption dechlorination and hydrogenation conversion method for chlorinated pyrolysis oil according to claim 1, characterized in that, The hydrodechlorination reaction conditions in the radial moving bed reactive adsorption dechlorination reactor in step S2 are: reaction temperature 220–340℃, hydrogen partial pressure 4–12 MPa, and liquid hourly space velocity 0.5–2 h⁻¹. -1 The volume ratio of hydrogen to liquid feedstock is 100–1000 Nm³. 3 / m 3 .

6. The radial moving bed reactive adsorption dechlorination and hydrogenation conversion method for chlorinated pyrolysis oil according to claim 1, characterized in that, The core-shell structured integrated hydrodechlorination catalyst comprises a core and an outer shell adsorption layer covering the outer surface of the core. The core is a support for the hydrodechlorination active metal component, and the outer shell adsorption layer uses zinc oxide as the main adsorption component and is supplemented with structural stabilizing components. It achieves near-source capture and fixation of chlorinated organic compounds for hydrodechlorination and the generation of HCl at the single-particle scale.

7. The radial moving bed reactive adsorption dechlorination and hydrogenation conversion method for chlorinated pyrolysis oil according to claim 6, characterized in that, In the core of the core-shell structured reactive adsorption integrated hydrodechlorination catalyst, the active metal component for hydrodechlorination is selected from one or more of nickel, molybdenum, tungsten, and cobalt. The total content of the active metal component for hydrodechlorination in the core is 0.5 to 30 wt% based on metal oxides. The support for the core is selected from alumina, silica, zirconium oxide, molecular sieves, or composite supports thereof.

8. The radial moving bed reactive adsorption dechlorination and hydrogenation conversion method for chlorinated pyrolysis oil according to claim 7, characterized in that, In the outer shell adsorption layer of the core-shell structured reactive adsorption integrated hydrodechlorination catalyst, the zinc oxide content is 70-95 wt%, and the structural stabilizing component is selected from one or more of alumina, silicon dioxide, and zirconium oxide, with a content of 5-30 wt%.

9. The radial moving bed reactive adsorption dechlorination and hydrogenation conversion method for chlorinated pyrolysis oil according to claim 1, characterized in that, The reaction conditions for the fixed-bed deep hydrorefining reactor are: reaction temperature 320–380℃, hydrogen partial pressure 4–12 MPa, and liquid hourly space velocity 0.5–2 h⁻¹. -1 The volume ratio of hydrogen to liquid feedstock is 100–1000 Nm³. 3 / m 3 .

10. The radial moving bed reactive adsorption dechlorination and hydrogenation conversion method for chlorinated pyrolysis oil according to claim 9, characterized in that, The deep hydrorefined product obtained in step S3 is subjected to gas-liquid separation, stripping, and three-phase separation to obtain naphtha fraction and clean pyrolysis oil. The separated circulating hydrogen is returned to the fixed-bed selective hydrorefining reactor for recycling.

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