Method and system for preparing biological aviation fuel by hydrogenation of waste tire pyrolysis oil

Abstract

The invention relates to the technical field of waste tire recovery, in particular to a method and a system for preparing biological aviation fuel by hydrogenation of waste tire pyrolysis oil, a pretreatment unit is used for performing multi-stage filtration and preheating treatment on the waste tire pyrolysis oil; the hydrogenation reaction unit is used for carrying out hydrogenation reaction and shallow cracking reaction on the pretreated waste tire pyrolysis oil; the separation and purification unit comprises a hot high-pressure separator, a dechlorination reactor, a cold high-pressure separator, a hot low-pressure separator and a cold low-pressure separator, and is used for carrying out dechlorination reaction and gas-oil-water separation treatment on a product of the shallow cracking reaction; the circulating hydrogen unit is used for providing mixed hydrogen for the system; and the fractionation unit is used for fractionating the product separated by the separation and purification unit to obtain the biological aviation fuel. According to the method, the waste tire pyrolysis oil is converted into the biological aviation fuel by adopting a series hydrogenation process, so that the problem of waste tire treatment is solved, and high-value utilization of resources is also realized.

Description

Technical Field

[0001] The invention relates to the technical field of waste tire recycling, and in particular to a method and system for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil. Background Art

[0002] With the continuous development of the automobile transportation industry, the amount of waste tires generated has also increased dramatically. Due to the characteristics of waste tires such as corrosion resistance and difficulty in decomposition under natural conditions, they have become a "black pollution" problem of concern in my country and the world. How to achieve the "reduction, harmlessness, greening, resource utilization, reuse and recycling" of waste tires is a major issue that needs to be solved in the rubber field. Thermal cracking of waste tires is one of the main ways to recycle waste tires. Waste tire pyrolysis oil is one of the main products generated by the pyrolysis of waste tires, and its density is generally greater than 915kg / m 3 , mainly containing aliphatic hydrocarbons, aromatic hydrocarbons, olefins and colloids, as well as non-hydrocarbon compounds such as sulfur, nitrogen, oxygen and chlorine. The pyrolysis oil has the advantages of high calorific value, low ash content, low viscosity and low residual carbon value, but it also has the defects of poor overall performance compared with diesel and high content of impurities such as sulfur, nitrogen and chlorine. Therefore, refining the waste tire pyrolysis oil, removing the non-hydrocarbon compounds such as sulfur, nitrogen, oxygen and chlorine contained therein, and improving the quality of the waste tire pyrolysis oil is an environmentally friendly technology to improve the utilization value of waste tire pyrolysis oil, and at the same time, it can alleviate the current situation of oil shortage in my country to a certain extent.

[0003] A variety of additives added during tire manufacturing (such as silane coupling agents, chlorinated paraffins, etc.) result in significant contents of impurities such as chlorine and silicon in the pyrolysis oil. During the hydrogenation process, chlorine is converted into hydrogen chloride, which can corrode equipment, and silicon is prone to clogging the catalyst pores, leading to deactivation. This is particularly fatal for an aviation fuel preparation system that requires long-term stable operation. The existing patent CN105001910 A discloses a method for combined hydrotreating of tire pyrolysis oil, a combined process of hydrodechlorination and hydrorefining. Aiming at the high content of impurity elements in waste tire pyrolysis oil, especially the influence of the presence of chlorine element on stainless steel equipment, it is applied to the process of waste tire oil upgrading, so as to achieve the purposes of improving product quality, reducing equipment material, extending the operation cycle of the device, and reducing investment. This invention adopts a two-stage separate hydrogenation process, with a complex process flow, high operation difficulty, and high energy consumption. The patent CN220520438U discloses a deep processing system for tire oil. This utility model is composed of a tire oil fractionation part, a diesel fraction hydrorefining part, a gasoline fraction hydrorefining part, etc., and is used for producing diesel and gasoline. This utility model needs to first separate the tire oil into two parts, namely the diesel fraction and the gasoline fraction, and then process them separately, making the process flow complex, the operation difficulty high, and the product distribution not easy to adjust. The patent CN118006362A discloses a deep processing system for hydrogenating tire pyrolysis oil. This invention is provided with a pre-furnace hydrogenation reactor and a post-furnace hydrogenation reactor. Through the improvement of the deep processing process of hydrogenating tire pyrolysis oil, a feed three-way is provided, which can switch the oil flow direction - select to input the first pre-furnace hydrogenation reactor or the feed heating furnace to extend the operation time of the device. In this way, when the first reactor is clogged, the first reactor will lose its function, and impurities such as dienes, gums, and silicon in the raw materials will quickly cause clogging of the post-furnace hydrogenation reactor, and the continuous operation time of the device has not been extended, and at the same time, it accelerates the coking and clogging of the catalyst in the post-furnace hydrogenation reactor.

[0004] Although the above technical solutions attempt to improve the quality of pyrolysis oil through the hydrogenation process, they all aim at producing ordinary gasoline and diesel components, without reports on the production of bio-liquid fuels, nor descriptions on the high-value utilization of renewable bio-source components in waste tire pyrolysis oil. Summary of the Invention

[0005] In view of this, the present invention proposes a method and system for hydrogenating waste tire pyrolysis oil to prepare bio-aviation fuel, which supplements the raw materials for producing bio-aviation fuel, and at the same time solves the problems of insufficient process flow and impurity removal efficiency in hydrogenating waste tire pyrolysis oil to prepare bio-aviation fuel, and realizes the long-term safe and stable operation of the system.

[0006] The technical solution of the present invention is realized as follows: The present invention provides a system for hydrogenating waste tire pyrolysis oil to prepare bio-aviation fuel, including:

[0007] A pretreatment unit for performing multi-stage filtration and preheating treatment on waste tire pyrolysis oil;

[0008] A hydrogenation reaction unit, including a low-temperature reactor, a refining reactor, and a reforming reactor connected in sequence, for performing hydrogenation reaction and mild cracking reaction on the pretreated waste tire pyrolysis oil;

[0009] A separation and purification unit, including a hot high-pressure separator, a dechlorination reactor, a cold high-pressure separator, a hot low-pressure separator, and a cold low-pressure separator, for performing dechlorination reaction and gas, oil, and water separation treatment on the products of the mild cracking reaction;

[0010] A recycle hydrogen unit for providing mixed hydrogen to the system;

[0011] A fractionation unit for fractionating the products separated by the separation and purification unit to obtain bio-aviation fuel and low-freezing-point biodiesel.

[0012] Based on the above technical solutions, preferably, the pretreatment unit includes a primary filter, a first heat exchanger, a secondary filter, and a second heat exchanger connected in sequence. A raw material buffer tank after filtration and a reaction feed pump are also provided between the secondary filter and the second heat exchanger. The waste tire pyrolysis oil after multi-stage filtration is mixed with mixed hydrogen and enters the second heat exchanger.

[0013] Based on the above technical solutions, preferably, the hydrogenation reaction unit includes:

[0014] A low-temperature reactor, the feed inlet of the low-temperature reactor is connected to the pretreatment unit,

[0015] A refining reactor, the feed inlet of the refining reactor is connected to the outlet of the low-temperature reactor through a third heat exchanger and a reaction feed heating furnace,

[0016] A reforming reactor, the feed inlet of the reforming reactor is connected to the outlet of the refining reactor through a fourth heat exchanger, and the outlet is connected to the hot high-pressure separator through a third heat exchanger.

[0017] Based on the above technical solutions, preferably, the separation and purification unit includes:

[0018] A hot high-pressure separator, the gas-phase outlet of the hot high-pressure separator is connected to the feed inlet of the dechlorination reactor, and the liquid-phase outlet is connected to the feed inlet of the hot low-pressure separator;

[0019] A dechlorination reactor, the outlet of the dechlorination reactor is connected to the feed inlet of the cold high-pressure separator through a second heat exchanger and a hot high-pressure gas air cooler;

[0020] A cold high-pressure separator, the gas-phase outlet of the cold high-pressure separator is connected to the recycle hydrogen unit, and the liquid-phase outlet is connected to the outside;

[0021] Hot low-pressure separator. The gas-phase outlet of the hot low-pressure separator is connected to the feed inlet of the cold low-pressure separator through the fifth heat exchanger and the hot low-pressure gas air cooler, and the liquid-phase outlet is connected to the fractionation unit.

[0022] Cold low-pressure separator. Both the gas-phase outlet and the liquid-phase outlet of the cold low-pressure separator are connected to the outside, and the oil-phase outlet is connected to the fractionation unit.

[0023] On the basis of the above technical solutions, preferably, the recycle hydrogen unit includes a recycle hydrogen desulfurization tower and a recycle hydrogen compressor. The inlet of the recycle hydrogen desulfurization tower is connected to the gas-phase outlet of the cold high-pressure separator, and the outlet is connected to the recycle hydrogen compressor. The mixed hydrogen is provided for the hydrogenation reaction unit and the separation and purification unit through the recycle hydrogen compressor.

[0024] On the basis of the above technical solutions, preferably, the inlet operating temperature of the low-temperature reactor is 150 - 180 °C, the operating pressure is 10.0 - 18.0 MPa(G), the volume hourly space velocity of the desilication agent is 4.0 - 6.0 h -1 , the volume hourly space velocity of the protective agent is 1.0 - 3.0 h -1 , the volume hourly space velocity of the main catalyst is 2.0 - 4.0 h -1 , the hydrogen-oil volume ratio is 500:1 - 1000:1 Nm 3 / m 3 ; the inlet operating temperature of the refining reactor is 320 - 360 °C, the operating pressure is 10.0 - 18.0 MPa(G), the volume hourly space velocity of the hydrofining catalyst is 0.5 - 2.0 h -1 , the inlet operating temperature of the reforming reactor is 330 - 350 °C, the volume hourly space velocity of the hydroreforming catalyst is 3.0 - 6.0 h -1 , the hydrogen-oil volume ratio is 500:1 - 1000:1 Nm 3 / m 3 .

[0025] On the basis of the above technical solutions, preferably, the desilication agent is activated carbon, the protective agent is a low-activity catalyst, and the main catalyst is an alumina support and Ni or Mo supported on the support.

[0026] On the basis of the above technical solutions, preferably, the hot high-pressure separator uses hot hydrogen stripping, and the flow rate of the hot hydrogen is 10 - 20% of the recycle hydrogen flow rate; the temperature of the hot hydrogen is 20 - 30 °C higher than the temperature of the reaction product entering the hot high-pressure separator, and the stripping internals use 6 - 9 layers of sieve trays or valve trays.

[0027] On the basis of the above technical solutions, preferably, the inlet operating temperature of the dechlorination reactor is 250 - 300 °C; the dechlorination agent, by weight, includes 55 - 65 parts of calcium oxide, 8 - 12 parts of cerium oxide, 12 - 18 parts of magnesium oxide, and 12 - 18 parts of diatomaceous earth.

[0028] On the basis of the above technical solutions, preferably, the preparation method of the dechlorination agent includes: weighing each component according to the raw material composition, mixing, adding a polyvinyl alcohol solution accounting for 1-2% of the total mass of the raw materials, pressing into a mold, calcining at 250-300 °C for 1-2 h, then heating up to 500-550 °C and calcining for 2-3 h, and crushing and screening the calcined product to obtain the dechlorination agent.

[0029] The present invention also provides a method for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil, which includes the following steps:

[0030] S1. Filter and preheat the waste tire pyrolysis oil, and then perform low-temperature hydrogenation treatment;

[0031] S2. After the low-temperature hydrogenation effluent is preheated in two stages, perform hydrofining reaction and mild cracking reaction in sequence;

[0032] S3. Subject the cracking reaction product to thermal high-pressure separation treatment to obtain a first gas phase and a first liquid phase. After the first gas phase undergoes a dechlorination reaction, perform cold high-pressure separation treatment to obtain a second gas phase, a first oil phase, and a second liquid phase;

[0033] S4. Subject the first oil phase to cold low-pressure separation treatment to collect the oil phase. The second gas phase enters the recycle hydrogen unit and undergoes a desulfurization reaction to obtain recycle hydrogen, and the second liquid phase is discharged; the first liquid phase undergoes thermal low-pressure separation treatment to obtain a third gas phase and a third liquid phase. After the third gas phase is condensed, it undergoes cold low-pressure separation treatment to collect the oil phase;

[0034] S5. Mix the third liquid phase and the oil phase for fractionation treatment to obtain bio-aviation fuel and low-freezing-point biodiesel.

[0035] The method and system for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil of the present invention have the following beneficial effects compared with the prior art:

[0036] (1) The system for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil provided by the present invention realizes the efficient recycling and high-value conversion of waste tire resources through the organic combination of a pretreatment unit, a hydrogenation reaction unit, a separation and purification unit, a recycle hydrogen unit, and a fractionation unit. This system adopts a series hydrogenation process, fully utilizes the biological source characteristics of waste tire pyrolysis oil, and under the conditions of low investment, operating cost, and energy consumption, converts waste tire pyrolysis oil into bio-naphtha, bio-aviation fuel, low-freezing-point diesel, and tail oil that can be used as raw materials for lubricating oil base oil. It not only solves the problem of waste tire treatment but also realizes the high-value utilization of resources; (2) The pretreatment unit adopts a gradient filtration system composed of a primary filter and a secondary filter, combined with the design of a double heat exchanger and a buffer tank, ensuring the purity and stable supply of the raw materials, effectively preventing the adverse effects of impurities on downstream equipment and catalysts, and improving the raw material adaptability and process stability of the entire system;

[0037] (3) The hydrogenation reaction unit adopts an innovative three-stage series reactor structure. The reactors in the low-temperature section are filled with desilicifying agent, protective agent, and low-temperature highly active hydrogenation catalyst in a graded manner, achieving hydrodesilication and diolefin removal under milder conditions, effectively avoiding coking and blockage of the subsequent main reactor; the design of the parallel hydrogenation reactors, in cooperation with the three-way switching valve, realizes the online hot standby function of the reactors, significantly extending the continuous operation cycle of the unit, improving the system stability and the service life of the catalyst;

[0038] (4) The method for dechlorination of hot high-pressure separator gas at 250 - 300 °C proposed in the present invention, through a specially designed dechlorination reactor and multi-component dechlorinating agent, enables chlorine to react with the dechlorinating agent and be efficiently adsorbed by the bed layer, ensuring the dechlorination efficiency, effectively avoiding the corrosion risk of chlorides to downstream equipment pipelines, and guaranteeing the long-term stable operation of the system; meanwhile, the dechlorinating agent forms a "adsorption - catalysis - fixation" cascade dechlorination mechanism through four components: diatomite first physically adsorbs chlorides, cerium oxide catalyzes the decomposition of complex organic chlorides, and calcium oxide and magnesium oxide permanently fix chlorine through chemical reactions. This multiple synergistic effect not only significantly improves the dechlorination efficiency and the service life of the dechlorinating agent, but also enhances the adaptability of the system to temperature fluctuations and feed component changes, providing a stable and reliable dechlorination guarantee for the hydrogenation process of waste tire pyrolysis oil;

[0039] (5) A stripping internal component is provided in the hot high-pressure separator, and the hot hydrogen stripping technology is adopted, significantly reducing the carry-over amount of hydrogen chloride generated by the hydrogenation reaction in the hot high-pressure separator oil, forming a double dechlorination guarantee with the dechlorination reactor, eliminating the corrosion risk of downstream equipment pipelines from the source, and improving the safety of the entire system and the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0041] Figure 1 It is a schematic structural diagram of the system for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil of the present invention.

[0042] The reference numerals are as follows:

[0043] 1. Primary filter; 2. First heat exchanger; 3. Secondary filter; 4. Buffer tank for filtered raw material; 5. Reaction feed pump; 6. Second heat exchanger; 7. Low-temperature reactor; 8. Third heat exchanger; 9. Reaction feed heating furnace; 10. Refining reactor; 11. Fourth heat exchanger; 12. Upgrading reactor; 13. Hot high-pressure separator; 14. Dechlorination reactor; 15. Air cooler for hot high-pressure separator gas; 16. Cold high-pressure separator; 17. Circulating hydrogen desulfurization tower; 18. Circulating hydrogen compressor; 19. Lean amine liquid pump; 20. Hot low-pressure separator; 21. Fifth heat exchanger; 22. Air cooler for hot low-pressure separator gas; 23. Cold low-pressure separator; 24. Fractionation system; 25. First three-way valve; 26. Second three-way valve Detailed implementation manners

[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] As Figure 1 shown, the present invention provides a system for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil, including a pretreatment unit, a hydrogenation reaction unit, a separation and purification unit, a circulating hydrogen unit, and a fractionation unit. The pretreatment unit is used for performing multi-stage filtration and preheating treatment on the waste tire pyrolysis oil; the hydrogenation reaction unit includes a low-temperature reactor 7, a refining reactor 10, and an upgrading reactor 12 connected in sequence, and is used for performing hydrogenation reaction and mild cracking reaction on the pretreated waste tire pyrolysis oil; the separation and purification unit includes a hot high-pressure separator 13, a dechlorination reactor 14, a cold high-pressure separator 16, a hot low-pressure separator 20, and a cold low-pressure separator 23, and is used for performing dechlorination reaction and gas, oil, and water separation treatment on the products of the mild cracking reaction; the circulating hydrogen unit is used for providing mixed hydrogen for the system; the fractionation unit is used for performing fractionation treatment on the products separated by the separation and purification unit to obtain bio-aviation fuel and low-freezing-point biodiesel.

[0046] The system for preparing bio - aviation fuel by hydrogenation of waste tire pyrolysis oil of the present invention realizes the efficient recycling and high - value conversion of waste tire resources through the synergistic effect of five functional units. This system uses multi - stage filtration and pre - heating treatment in the pretreatment unit to ensure the quality of raw materials. Through the gradient temperature control of the three - stage series reactors in the hydrogenation reaction unit, precise hydrogenation and mild cracking are achieved. The dechlorination and multi - stage separation processes in the separation and purification unit are combined to remove harmful substances, and a stable hydrogen source is provided by the recycle hydrogen unit. Finally, through the treatment of the fractionation unit, high - quality products meeting aviation fuel standards are obtained. It not only solves the problem of waste tire treatment, reduces the environmental pollution burden, but also lowers the production cost of bio - aviation fuel, improves the resource utilization efficiency, provides a technical approach for the conversion of waste rubber resources into high - value - added aviation fuel, and has significant environmental benefits and economic value.

[0047] Further, the pretreatment unit includes a first - stage filter 1, a first heat exchanger 2, a second - stage filter 3, and a second heat exchanger 6 connected in sequence. A filtered raw material buffer tank 4 and a reaction feed pump 5 are also arranged between the second - stage filter 3 and the second heat exchanger 6. The waste tire pyrolysis oil after multi - stage filtration is mixed with mixed hydrogen and enters the second heat exchanger 6. Preferably, the first - stage filter 1 uses a mechanical self - cleaning filter with a filtration accuracy of 50 - 100 μm, and the second - stage filter 3 uses a Johnson wedge - wire filter with a filtration accuracy of 20 - 30 μm.

[0048] The pretreatment unit realizes the efficient purification and temperature control of waste tire pyrolysis oil by adopting a combination of multi - stage filters with gradually increasing precision and a dual heat - exchange system. Among them, the first - stage filter 1 and the Johnson wedge - wire second - stage filter 3 form a gradient filtration system from coarse to fine, effectively removing impurity particles of different sizes in the raw materials. The setting of the filtered raw material buffer tank 4 and the reaction feed pump 5 ensures the stability and continuity of the system's feeding. The series configuration of the first and second heat exchangers 6 realizes the staged pre - heating of the raw materials. Finally, the purified waste tire pyrolysis oil and mixed hydrogen are fully mixed and heated up, providing pure and appropriately - temperatureed reaction materials for the subsequent hydrogenation reaction unit, significantly improving the raw material adaptability and reaction efficiency of the entire system, and reducing the risks of downstream catalyst poisoning and equipment blockage.

[0049] Further, the hydrogenation reaction unit includes a low - temperature reactor 7, a refining reactor 10, and a reforming reactor 12. The reaction feed pump 5 is connected to the inlet of the low - temperature reactor 7 through the second heat exchanger 6. The outlet of the low - temperature reactor 7 is connected to the inlet of the refining reactor 10 through a third heat exchanger 8 and a reaction feed heating furnace 9. The inlet of the reforming reactor 12 is connected to the outlet of the refining reactor 10 through a fourth heat exchanger 11, and the outlet is connected to a hot high - pressure separator 13 through the third heat exchanger 8.

[0050] Preferably, mixed hydrogen is introduced into the pipeline between the reaction feed pump 5 and the second heat exchanger 6 to cause the waste tire pyrolysis oil pretreated by the pretreatment unit to be mixed with the mixed hydrogen for heat exchange and then enter the low-temperature reactor 7 for hydrogenation reaction.

[0051] The low-temperature reactor 7 adopts two or more parallel hydrogenation reactors, preferably two parallel hydrogenation reactors, one of which is in operation and the other is in hot standby. A first three-way valve 25 is provided at the reactor inlet. The three openings of the first three-way valve 25 are respectively connected to the second heat exchanger 6 and the two hydrogenation reactors. When the pressure drop of the operating reactor exceeds the allowable value, it is switched to the standby reactor. The standby reactor needs to be ensured to be in a hot standby state. A stream of circulating hydrogen is introduced from the shell-side outlet of the fifth heat exchanger 21 into the inlet pipeline of the standby reactor to ensure that the temperature difference between the standby reactor system and the operating reactor is less than 80 °C. The pipeline between the hydrogenation reactor and the first three-way valve 25 is connected to the circulating hydrogen unit, and mixed hydrogen is replenished into the hydrogenation reactor through the circulating hydrogen unit to carry out the preliminary hydrogenation reaction of the waste tire pyrolysis oil.

[0052] The inlet operating temperature of the low-temperature reactor 7 is 150 - 180 °C, the operating pressure is 10.0 - 18.0 MPa(G), the volume space velocity of the desiliconizing agent is 4.0 - 6.0 h -1 , the volume space velocity of the protective agent is 1.0 - 3.0 h -1 , the volume space velocity of the main catalyst is 2.0 - 4.0 h -1 , the hydrogen-oil volume ratio is 500:1 - 1000:1 Nm 3 / m 3 ; the desiliconizing agent is activated carbon, the protective agent is a low-activity catalyst. Preferably, the low-activity catalyst is CT-10 produced by UOP (U.S. Universal Oil Products) Company; the main catalyst is an alumina support and Ni or Mo supported on the support. Based on the total weight of the catalyst, Ni is 4% - 5% in terms of NiO, and Mo is 1.0% - 2.0% in terms of oxide.

[0053] The inlet operating temperature of the refining reactor 10 is 320 - 360 °C, the operating pressure is 10.0 - 18.0 MPa(G), the volume space velocity of the hydrorefining catalyst is 0.5 - 2.0 h -1 , the inlet operating temperature of the reforming reactor 12 is 330 - 350 °C, the volume space velocity of the hydroreforming catalyst is 3.0 - 6.0 h -1 , the hydrogen-oil volume ratio is 500:1 - 1000:1 Nm 3 / m 3 .

[0054] The hydrogenation reaction unit constructs a gradient hydrogenation system through a three-stage series reactor, achieving the efficient conversion of unsaturated hydrocarbons, sulfides, oxygen-containing compounds, etc. in waste tire pyrolysis oil, significantly improving the quality and yield of target products. The low-temperature reactor 7 adopts a dual-machine parallel hot standby design to ensure the continuous and stable operation of the system, and conducts preliminary hydrogenation treatment at a temperature of 150-180°C through a three-layer catalyst structure; the refining reactor 10 deeply removes impurities under high-temperature conditions of 320-360°C; the reforming reactor 12 precisely regulates the molecular structure under conditions of 330-350°C to form the carbon chain distribution characteristics required for aviation fuel.

[0055] Further, the separation and purification unit includes a hot high-pressure separator 13, a dechlorination reactor 14, a cold high-pressure separator 16, a hot low-pressure separator 20, and a cold low-pressure separator 23. The gas-phase outlet of the hot high-pressure separator 13 is connected to the feed inlet of the dechlorination reactor 14, and the liquid-phase outlet is connected to the feed inlet of the hot low-pressure separator 20; the outlet of the dechlorination reactor 14 is connected to the feed inlet of the cold high-pressure separator 16 through the second heat exchanger 6 and the hot high-pressure gas air cooler 15;

[0056] The gas-phase outlet of the cold high-pressure separator 16 is connected to the recycle hydrogen unit, the liquid-phase outlet is connected to the outside, and the oil-phase outlet is connected to the cold low-pressure separator 23; the gas-phase outlet of the hot low-pressure separator 20 is connected to the feed inlet of the cold low-pressure separator 23 through the fifth heat exchanger 21 and the hot low-pressure gas air cooler 22, and the liquid-phase outlet is connected to the fractionation unit; the gas-phase outlet and the liquid-phase outlet of the cold low-pressure separator 23 are both connected to the outside, and the oil-phase outlet is connected to the fractionation unit.

[0057] The cracking reaction products are separated by the hot high-pressure separator 13 to obtain a first gas phase and a first liquid phase. The first gas phase enters the dechlorination reactor 14 for dechlorination reaction, and then the dechlorinated product is condensed to 40-50°C by the hot high-pressure gas air cooler 15 and enters the cold high-pressure separator 16 for separation to obtain a second gas phase, a first oil phase, and a second liquid phase; the first liquid phase enters the hot low-pressure separator 20 for separation to obtain a third gas phase and a third liquid phase. The second gas phase enters the recycle hydrogen unit for desulfurization treatment to obtain hydrogen to provide hydrogen for the entire hydrogenation reaction system. The third gas phase enters the hot low-pressure gas air cooler 22 and is condensed and cooled to 45-50°C. The first oil phase and the condensed third gas phase both enter the cold low-pressure separator 23 for separation to obtain a second oil phase, a fourth liquid phase, and a fourth gas phase. The fourth liquid phase and the second liquid phase are both sulfur-containing sewage and are discharged from the hydrogen-containing system. The second oil phase and the third liquid phase are mixed and sent to the fractionation unit. The fourth gas phase is low-pressure gas and is directly discharged.

[0058] Preferably, the pipelines between the second heat exchanger 6 and the hot high-pressure gas air cooler 15 and near the hot high-pressure gas air cooler 15, and the pipelines between the second heat exchanger 6 and the hot low-pressure gas air cooler 22 and near the hot low-pressure gas air cooler 22 are both connected to demineralized water to inject demineralized water, so as to promote the products after dechlorination and the third gas phase to pass into the demineralized water for desalting treatment. The demineralized water is a NaOH solution with a mass fraction of 0.5%-3%.

[0059] Furthermore, at least two or more dechlorination reactors 14 are used in parallel. Preferably, two dechlorination reactors 14 are used in parallel. One is in operation and the other is in hot standby. A second three-way valve 26 is provided at the inlet of the dechlorination reactor 14. When the bed layer of the operating dechlorination reactor 14 is penetrated by chlorides (when the chlorine content in the outlet stream exceeds the standard), it is switched to the standby dechlorination reactor 14. The standby dechlorination reactor 14 needs to be ensured to be in a hot standby state. A stream of mixed hydrogen is introduced from the outlet of the shell side of the fourth heat exchanger 11 into the inlet pipeline of the standby reactor to ensure that the temperature difference between the standby dechlorination reactor 14 system and the in-use dechlorination reactor 14 is less than 50°C. The inlet operating temperature of the dechlorination reactor 14 is 250-300°C.

[0060] The dechlorination agent, by weight, includes 55-65 parts of calcium oxide, 8-12 parts of cerium oxide, 12-18 parts of magnesium oxide, and 12-18 parts of diatomite. The preparation method of the dechlorination agent includes: weighing each component according to the raw material composition, mixing, adding a polyvinyl alcohol solution accounting for 1-2% of the total mass of the raw materials, pressing into a mold, calcining at 250-300°C for 1-2 h, then heating to 500-550°C and calcining for 2-3 h, and crushing and screening the calcined product to obtain the dechlorination agent.

[0061] The dechlorination agent adopts a multi-stage cooperative design of "main active agent + catalytic promoter + structural stabilizer + carrier". Calcium oxide, as the main active component, provides a strong alkaline absorption center, which can efficiently capture and fix hydrogen chloride and organic chlorides to form stable calcium chloride; cerium oxide, as the catalytic promoter, utilizes the reversible conversion characteristics of cerium ions to enhance the redox ability of the system, promote the decomposition and conversion of organic chlorides, and at the same time improve the overall dechlorination rate; magnesium oxide forms an alkaline cooperative system with calcium oxide, which not only supplements the dechlorination activity, but more importantly, enhances the thermal stability of the system and prevents the sintering and inactivation of calcium oxide at high temperatures; diatomite, as a porous carrier material, provides a large specific surface area and excellent gas permeability, highly disperses the active components, increases the gas-solid contact area, and at the same time improves the mechanical strength and compression resistance of the dechlorination agent.

[0062] The hot high-pressure separator 13 adopts the process of hot hydrogen stripping. The stripping internals of the hot high-pressure separator 13 can use sieve trays or valve trays, preferably sieve trays, and generally have 6 to 9 trays. The flow rate of the hot hydrogen is generally 10 to 20% of the recycle hydrogen flow rate. The temperature of the hot hydrogen is generally 20 to 30 °C higher than the temperature of the reaction product entering the hot high-pressure separator 13.

[0063] The separation and purification unit adopts a cooperative process system of "multistage separation + specific dechlorination". Through the series-parallel combination of the hot high-pressure separator 13, the dual-machine hot standby dechlorination reactor 14, the cold high-pressure separator 16, the hot low-pressure separator 20, and the cold low-pressure separator 23, the efficient separation of the gas, oil, and water phases in the hydrogenation reaction product and the deep removal of harmful substances are realized. This unit ensures the full removal of corrosive substances such as chlorides and sulfides through precise temperature gradient control (from 250 - 300 °C for thermal separation to 40 - 50 °C for condensation) and desalted water injection, effectively preventing equipment corrosion and downstream catalyst poisoning; at the same time, through the cascaded utilization of heat and the reasonable flow direction distribution of the gas-phase product, the energy utilization efficiency is optimized. The gas-phase product enters the recycle hydrogen unit to form a hydrogen closed-loop cycle, while the oil-phase product enters the fractionation unit for further refining, realizing the efficient separation of materials and the optimized utilization of energy, laying a foundation for the production of high-quality bio-aviation fuel.

[0064] Furthermore, the recycle hydrogen unit includes a recycle hydrogen desulfurization tower 17 and a recycle hydrogen compressor 18. The inlet of the recycle hydrogen desulfurization tower 17 is connected to the gas-phase outlet of the cold high-pressure separator 16, and the outlet is connected to the recycle hydrogen compressor 18. The recycle hydrogen compressor 18 provides mixed hydrogen for the hydrogenation reaction unit and the separation and purification unit.

[0065] The fractionation unit includes a reaction product fractionation system 24, which fractionates bio-naphtha, bio-aviation fuel, low-freezing-point biodiesel, and tail oil.

[0066] The present invention also provides a method for hydrogenating waste tire pyrolysis oil to prepare bio-aviation fuel, including the following steps:

[0067] S1. Filter and preheat the waste tire pyrolysis oil, and then perform low-temperature hydrogenation treatment.

[0068] Specifically, the waste tire pyrolysis oil enters the primary filter 1 for filtration, then enters the first heat exchanger 2 for heat exchange to 110 - 120 °C, is filtered by the secondary filter 3, then pressurized by the reaction feed pump 5, and then mixed with the mixed hydrogen from the recycle hydrogen unit. It is heat exchanged with the reaction product through the second heat exchanger 6 to 150 - 180 °C and enters the low-temperature section hydrogenation reactor for reaction to remove silicon, metals, diolefins, etc.

[0069] S2. After the low-temperature hydrogenation effluent is preheated twice, it undergoes a hydrofining reaction and a mild cracking reaction in sequence;

[0070] S3. Subject the cracking reaction product to thermal high-pressure separation to obtain a first gas phase and a first liquid phase. After the dechlorination reaction of the first gas phase, perform cold high-pressure separation to obtain a second gas phase, a first oil phase, and a second liquid phase;

[0071] S4. Subject the first oil phase to cold low-pressure separation to collect a second oil phase. The second gas phase enters the recycle hydrogen unit and undergoes a desulfurization reaction to obtain recycle hydrogen, and the second liquid phase is discharged. The first liquid phase undergoes thermal low-pressure separation to obtain a third gas phase and a third liquid phase. After the third gas phase is condensed, it undergoes cold low-pressure separation to collect the second oil phase;

[0072] S5. Mix the third liquid phase and the second oil phase and perform fractionation to obtain bio-aviation fuel and low-freezing-point biodiesel.

[0073] Specifically, the outlet material of the low-temperature stage hydrogenation reactor enters the third heat exchanger 8 for heat exchange, and then is heated to 340 - 360 °C by the reaction feed heating furnace 9 and enters the hydrofining reactor 10. In the hydrofining reactor 10, dechlorination, desulfurization, denitrification, deoxidation, saturation of unsaturated hydrocarbons, etc. are carried out. The outlet material of the hydrofining reactor 10 enters the fourth heat exchanger 11 for heat exchange to 300 - 320 °C, then enters the hydro-upgrading reactor 12 for mild cracking reaction, and then is heated to 250 - 300 °C by the third heat exchanger 8 and enters the upper middle part of the thermal high-pressure separator 13. A separation internal part is provided in the thermal high-pressure separator 13. The hot mixed hydrogen drawn from the fourth heat exchanger 11 enters the lower middle part of the thermal high-pressure separator 13. The separated first gas phase enters the thermal high-pressure gas dechlorination reactor 14 for dechlorination and then enters the tube side of the second heat exchanger 6. An intermittent water injection port is provided near the inlet of the second heat exchanger 6 in the pipeline. After that, it is condensed and cooled to 45 - 50 °C by the thermal high-pressure gas air cooler 15 and enters the cold high-pressure separator 16 for gas, oil, and water separation to obtain the second gas phase, the first oil phase, and the second liquid phase. Demineralized water is injected near the inlet of the thermal high-pressure gas air cooler in the pipeline leading to the thermal high-pressure gas air cooler. The second gas phase is further separated by liquid and then enters the recycle hydrogen desulfurization tower 17 to remove hydrogen sulfide in the recycle hydrogen. The first oil phase enters the cold low-pressure separator 23, and the second liquid phase is sulfur-containing sewage and is discharged from the hydrogen-containing system.

[0074] The first liquid phase enters the thermal low-pressure separator 20 through the hydraulic turbine of the lean amine liquid pump 19 for gas-liquid separation to obtain the third gas phase and the third liquid phase. The third liquid phase and the second oil phase separated from the cold low-pressure separator 23 enter the fractionation unit together. The third gas phase enters the fifth heat exchanger 21. An intermittent water injection port is provided near the inlet of the tube side of the fifth heat exchanger 21 in the pipeline. After that, it is condensed and cooled to 45 - 50 °C by the thermal low-pressure gas air cooler 22 and is incorporated into the cold low-pressure separator 23. Gas, oil, and water separation are carried out in the cold low-pressure separator 23 to obtain the second oil phase, the fourth liquid phase, and the fourth gas phase. Demineralized water is injected near the inlet of the thermal low-pressure gas air cooler in the pipeline. The fourth gas phase is low-pressure gas and is discharged from the hydrogen-containing system; the fourth liquid phase is sulfur-containing sewage and is discharged from the hydrogen-containing system.

[0075] As can be seen from Table 1, the sulfur content, nitrogen content, chlorine content, silicon + calcium content, bromine value, acid value, etc. of waste tire pyrolysis oil are all factors that must be considered in the deep processing of waste tire pyrolysis oil. The present invention provides a method for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil in view of its characteristics. Through the waste tire classification and recycling strategy, the proportion of chlorinated rubber entering the waste tire pyrolysis oil is effectively controlled, the initial chlorine content of the pyrolysis oil is significantly reduced, the chlorine corrosion risk faced by subsequent processing equipment is alleviated, and the advantages of low investment, low operating cost and low energy consumption of the series hydrogenation process are fully exerted. At the same time, the biological source attribute of the waste tire pyrolysis oil is retained, and the characteristics of the final product as a biofuel are enhanced.

[0076] Table 1 Typical properties of waste tire pyrolysis oil

[0077]

[0078]

[0079] The technical solution of the present invention will be further described below through examples.

[0080] Example 1

[0081] This example proposes a method for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil, including the following steps:

[0082] S1. Perform primary filtration, primary heating and secondary filtration on the waste tire pyrolysis oil. The filtration accuracy of the primary filtration is 80 μm, the filtration accuracy of the secondary filtration is 25 μm, and the temperature of the waste tire pyrolysis oil after primary heating is 105 °C; then mix the pretreated waste tire pyrolysis oil and mixed hydrogen and perform primary preheating to 150 °C, and enter the low-temperature reactor. The inlet operating temperature of the low-temperature reactor is 150 °C, the operating pressure is 13.0 MPa(G), the volume space velocity of activated carbon is 6.0 h -1 , the volume space velocity of CT-10 is 2.0 h -1 , the volume space velocity of the main catalyst is 2.0 h -1 , the main catalyst alumina support and Ni supported on the support, Ni is 4.5% in terms of NiO, and the hydrogen-oil volume ratio is 800:1 Nm 3 / m 3 .

[0083] S2. After the low-temperature hydrogenation effluent is preheated to 340 °C in the secondary preheater, carry out hydrofining reaction. The inlet operating temperature of the hydrofining reactor is 340 °C, the operating pressure is 12.0 MPa(G), the volume space velocity of the hydrofining catalyst is 1.0 h -1 , and the hydrogen-oil volume ratio is 800:1 Nm 3 / m 3; The product is heat-exchanged to 340 °C for a mild cracking reaction. The inlet operating temperature of the upgrading reactor is 340 °C, and the volume hourly space velocity of the hydro-upgrading catalyst is 3.0 h -1 , and the hydrogen-oil volume ratio is 800:1 Nm 3 / m 3 ;

[0084] S3. The cracking reaction product is subjected to hot high-pressure separation to obtain a first gas phase and a first liquid phase. The first gas phase is subjected to a dechlorination reaction and then cold high-pressure separation to obtain a second gas phase, a first oil phase, and a second liquid phase;

[0085] The inlet operating temperature of the dechlorination reactor is 285 °C; the dechlorination agent, by weight, includes 60 parts of calcium oxide, 10 parts of cerium oxide, 16 parts of magnesium oxide, and 16 parts of diatomaceous earth. The preparation method of the dechlorination agent includes: weighing each component according to the raw material composition, adding a 1.5% polyvinyl alcohol solution based on the total mass of the raw materials, pressing into a mold, calcining at 280 °C for 1.5 h, then raising the temperature to 525 °C and calcining for 2.5 h, and crushing and screening the calcined product to obtain the dechlorination agent.

[0086] S4. The first oil phase is subjected to cold low-pressure separation to collect a second oil phase. The second gas phase enters the recycle hydrogen unit and undergoes a desulfurization reaction to obtain recycle hydrogen, and the second liquid phase is discharged; the first liquid phase is subjected to hot low-pressure separation to obtain a third gas phase and a third liquid phase. The third gas phase is condensed and then subjected to cold low-pressure separation to collect the second oil phase; demineralized water is injected at the inlets of the hot high-pressure gas air cooler and the hot low-pressure gas air cooler;

[0087] S5. The third liquid phase and the second oil phase are mixed and fractionated to obtain bio-aviation fuel and low-freezing-point biodiesel.

[0088] Example 2

[0089] This example proposes a method for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil, including the following steps:

[0090] S1. The waste tire pyrolysis oil is subjected to primary filtration, initial heating, and secondary filtration. The filtration accuracy of the primary filtration is 50 μm, and the filtration accuracy of the secondary filtration is 20 μm. The temperature of the waste tire pyrolysis oil after initial heating is 110 °C; then the pretreated waste tire pyrolysis oil and mixed hydrogen are mixed and preheated to 160 °C in the first stage and enter the low-temperature reactor. The inlet operating temperature of the low-temperature reactor is 160 °C, the operating pressure is 11.0 MPa(G), the volume hourly space velocity of the activated carbon is 5.0 h -1 , the volume hourly space velocity of CT-10 is 1.0 h -1 , the volume hourly space velocity of the main catalyst is 3.0 h -1 , the main catalyst alumina support and Ni supported on the support, Ni is 4% in terms of NiO, and the hydrogen-oil volume ratio is 500:1 Nm 3 / m 3 。

[0091] S2. After the low-temperature hydrogenation effluent is preheated to 320 °C in two stages, hydrofining reaction is carried out. The operating temperature at the inlet of the hydrofining reactor is 320 °C, the operating pressure is 10.0 MPa(G), and the volume hourly space velocity of the hydrofining catalyst is 0.5 h -1 ; The product is heat-exchanged to 350 °C for mild cracking reaction. The operating temperature at the inlet of the upgrading reactor is 350 °C, and the volume hourly space velocity of the hydro-upgrading catalyst is 4.5 h -1 , and the hydrogen-oil volume ratio is 500:1 Nm 3 / m 3 ;

[0092] S3. The cracking reaction product is subjected to hot high-pressure separation to obtain the first gas phase and the first liquid phase. The first gas phase is subjected to dechlorination reaction and then cold high-pressure separation to obtain the second gas phase, the first oil phase and the second liquid phase;

[0093] The operating temperature at the inlet of the dechlorination reactor is 280 °C; The dechlorination agent, by weight, includes 55 parts of calcium oxide, 8 parts of cerium oxide, 12 parts of magnesium oxide and 12 parts of diatomite. The preparation method of the dechlorination agent includes: weighing each component according to the raw material composition, adding 1% polyvinyl alcohol solution of the total mass of the raw materials, pressing into shape, calcining at 250 °C for 2 h, then heating to 500 °C and calcining for 3 h, and crushing and screening the calcined product to obtain the dechlorination agent.

[0094] S4. The first oil phase is subjected to cold low-pressure separation to collect the second oil phase. The second gas phase enters the recycle hydrogen unit and undergoes desulfurization reaction to obtain recycle hydrogen, and the second liquid phase is discharged; The first liquid phase is subjected to hot low-pressure separation to obtain the third gas phase and the third liquid phase. The third gas phase is condensed and then subjected to cold low-pressure separation to collect the second oil phase; Demineralized water is injected at the inlets of the hot high-pressure gas air cooler and the hot low-pressure gas air cooler;

[0095] S5. The third liquid phase and the second oil phase are mixed for fractionation to obtain bio-aviation fuel and low-freezing-point biodiesel.

[0096] Example 3

[0097] This example presents a method for preparing bio-aviation fuel by hydrogenation of waste tire pyrolysis oil, including the following steps:

[0098] S1. First, subject the waste tire pyrolysis oil to primary filtration, initial heating, and secondary filtration. The filtration accuracy of the primary filtration is 100 μm, and that of the secondary filtration is 30 μm. The temperature of the waste tire pyrolysis oil after initial heating is 120 °C. Then, mix the pretreated waste tire pyrolysis oil with mixed hydrogen and preheat it to 180 °C in the first stage, and then feed it into the low-temperature reactor. The inlet operating temperature of the low-temperature reactor is 180 °C, the operating pressure is 18.0 MPa(G), the volume space velocity of activated carbon is 4.0 h -1 , the volume space velocity of CT-10 is 3.0 h -1 , the volume space velocity of the main catalyst is 4.0 h -1 , the main catalyst is alumina support and Ni supported on the support. Ni is 5% in terms of NiO, and the hydrogen-oil volume ratio is 1000:1 Nm 3 / m 3 .

[0099] S2. After the low-temperature hydrogenation effluent is preheated to 360 °C in the second stage, carry out hydrofining reaction. The inlet operating temperature of the hydrofining reactor is 360 °C, the operating pressure is 16.5 MPa(G), and the volume space velocity of the hydrofining catalyst is 2.0 h -1 ; the product is heat-exchanged to 330 °C for mild cracking reaction. The inlet operating temperature of the reforming reactor is 330 °C, the volume space velocity of the hydro-upgrading catalyst is 6.0 h -1 , and the hydrogen-oil volume ratio is 1000:1 Nm 3 / m 3 ;

[0100] S3. Subject the cracking reaction product to hot high-pressure separation to obtain the first gas phase and the first liquid phase. After the first gas phase undergoes dechlorination reaction, carry out cold high-pressure separation to obtain the second gas phase, the first oil phase, and the second liquid phase;

[0101] The inlet operating temperature of the dechlorination reactor is 300 °C. The dechlorination agent, by weight, includes 65 parts of calcium oxide, 12 parts of cerium oxide, 18 parts of magnesium oxide, and 18 parts of diatomaceous earth. The preparation method of the dechlorination agent includes: weighing each component according to the raw material composition, mixing, adding 2% of the total mass of the raw materials of polyvinyl alcohol solution, pressing into shape, calcining at 300 °C for 1 h, then raising the temperature to 550 °C and calcining for 2 h, and crushing and screening the calcined product to obtain the dechlorination agent.

[0102] S4. Subject the first oil phase to cold low-pressure separation to collect the second oil phase. The second gas phase enters the recycle hydrogen unit and undergoes desulfurization reaction to obtain recycle hydrogen, and the second liquid phase is discharged; the first liquid phase undergoes hot low-pressure separation to obtain the third gas phase and the third liquid phase. After the third gas phase is condensed, it undergoes cold low-pressure separation to collect the second oil phase; inject demineralized water at the inlets of the hot high-pressure gas air cooler and the hot low-pressure gas air cooler;

[0103] S5. The third liquid phase and the second oil phase are mixed for fractional distillation treatment to obtain bio-aviation fuel and low-freezing-point biodiesel.

[0104] Comparative Example 1

[0105] This comparative example presents a method for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil. The steps are the same as those in Example 1, except that the inlet operating temperature of the dechlorination reactor is 250 °C.

[0106] Comparative Example 2

[0107] This comparative example presents a method for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil. The steps are the same as those in Example 1, except that the dechlorination agent, by weight, includes 60 parts of calcium oxide, 16 parts of magnesium oxide, and 26 parts of diatomaceous earth, and the total mass of the dechlorination agent is the same as that in Example 1. The preparation method of the dechlorination agent includes: weighing each component according to the raw material composition, mixing them, adding a 1.5% polyvinyl alcohol solution based on the total mass of the raw materials, pressing into shape, calcining at 280 °C for 1.5 h, then raising the temperature to 525 °C and calcining for 2.5 h, and crushing and screening the calcined product to obtain the dechlorination agent.

[0108] Comparative Example 3

[0109] This comparative example presents a method for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil. The steps are the same as those in Example 1, except that the dechlorination agent, by weight, includes 60 parts of calcium oxide, 10 parts of cerium oxide, and 32 parts of diatomaceous earth, and the total mass of the dechlorination agent is the same as that in Example 1. The preparation method of the dechlorination agent includes: weighing each component according to the raw material composition, mixing them, adding a 1.5% polyvinyl alcohol solution based on the total mass of the raw materials, pressing into shape, calcining at 280 °C for 1.5 h, then raising the temperature to 525 °C and calcining for 2.5 h, and crushing and screening the calcined product to obtain the dechlorination agent.

[0110] The properties of the refined naphtha, refined diesel, and tail oil of the hydrogenation reaction products in the examples and comparative examples through the reaction product fractionation system are shown in Tables 2 and 3.

[0111] Table 2 Examples

[0112]

[0113]

[0114] Table 3 Comparative Examples

[0115]

[0116] As can be seen from Tables 2 and 3, the technical solution of the present invention can significantly reduce the chlorine content of waste tire pyrolysis oil, improve the adsorption efficiency, and reduce the risk of chlorine corrosion of facilities such as pipelines in the subsequent deep processing equipment of waste tire pyrolysis oil.

[0117] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A system for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil, characterized in that: include: A pretreatment unit, used for multi-stage filtration and preheating of waste tire pyrolysis oil; The hydrogenation reaction unit includes a low temperature section reactor, a refining reactor and a reforming reactor which are connected in sequence, and is used for hydrogenation reaction and shallow cracking reaction of the pre-treated waste tire pyrolysis oil; A separation and purification unit, including a hot high-pressure separator, a dechlorination reactor, a cold high-pressure separator, a hot low-pressure separator and a cold low-pressure separator, is used to carry out dechlorination reaction and gas, oil and water separation treatment on the product of the shallow cracking reaction; A circulating hydrogen unit for providing mixed hydrogen to the system; The fractionation unit is used to fractionate the product separated by the separation and purification unit to obtain bio-aviation fuel and low-freezing-point biodiesel.

2. The system for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil as claimed in claim 1, characterized in that: The pretreatment unit includes a primary filter, a first heat exchanger, a secondary filter and a second heat exchanger which are connected in sequence. A post-filter raw material buffer tank and a reaction feed pump are also arranged between the secondary filter and the second heat exchanger. The waste tire pyrolysis oil after multi-stage filtration is mixed with mixed hydrogen and enters the second heat exchanger.

3. The system for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil as claimed in claim 1, characterized in that: The hydrogenation reaction unit includes: The low temperature section reactor, the feed port of the low temperature section reactor is connected to the pretreatment unit, The feed port of the refining reactor is connected to the discharge port of the low temperature section reactor through the third heat exchanger and the reaction feed heating furnace. The reforming reactor has a feed port connected to the discharge port of the refining reactor through the fourth heat exchanger, and the discharge port is connected to the hot high-pressure separator through the third heat exchanger.

4. The system for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil as claimed in claim 1, characterized in that: The separation and purification unit includes: A hot high-pressure separator, wherein the gas phase outlet of the hot high-pressure separator is connected to the feed port of the dechlorination reactor, and the liquid phase outlet is connected to the feed port of the hot low-pressure separator; A dechlorination reactor, wherein the discharge port of the dechlorination reactor is connected to the feed port of the cold high-pressure separator through a second heat exchanger and a hot high-gas air cooler; A cold high-pressure separator, wherein the gas phase outlet of the cold high-pressure separator is connected to the circulating hydrogen unit, the liquid phase outlet is connected to the outside, and the oil phase outlet is connected to the feed port of the cold low-pressure separator; A hot low-pressure separator, the gas phase outlet of the hot low-pressure separator is connected to the feed port of the cold low-pressure separator through the fifth heat exchanger and the hot low-pressure air cooler, and the liquid phase outlet is connected to the fractionation unit; A cold low-pressure separator, the gas phase outlet and the liquid phase outlet of the cold low-pressure separator are both connected to the outside, and the oil phase outlet is connected to the fractionation unit.

5. The system for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil as claimed in claim 1, characterized in that: The circulating hydrogen unit includes a circulating hydrogen desulfurization tower and a circulating hydrogen compressor. The air inlet of the circulating hydrogen desulfurization tower is connected to the gas phase outlet of the cold high-pressure separator, and the air outlet is connected to the circulating hydrogen compressor. The circulating hydrogen compressor provides mixed hydrogen to the hydrogenation reaction unit and the separation and purification unit.

6. The system for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil as claimed in claim 3, characterized in that: The inlet operating temperature of the low temperature reactor is 150-180°C, the operating pressure is 10.0-18.0 MPa (G), and the volume space velocity of the desiliconizer is 4.0-6.0 h -1 , protective agent volume space velocity 1.0~3.0h -1 , main catalyst volume space velocity 2.0~4.0h -1 , hydrogen oil volume ratio is 500:1~1000:1Nm 3 / m 3 ; The operating temperature of the refining reactor inlet is 320-360°C, the operating pressure is 10.0-18.0MPa(G), and the volume space velocity of the hydrofining catalyst is 0.5-2.0h -1 The inlet operating temperature of the reforming reactor is 330-350℃, and the volume space velocity of the hydrogenation reforming catalyst is 3.0-6.0h -1 , hydrogen oil volume ratio is 500:1~1000:1Nm 3 / m 3 .

7. A system for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil as claimed in claim 6, characterized in that: The desiliconizing agent is activated carbon, the protective agent is a low-activity catalyst, and the main catalyst is an alumina carrier and Ni or Mo loaded on the carrier.

8. The system for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil as claimed in claim 4, characterized in that: The hot high-pressure separator adopts hot hydrogen stripping, and the flow rate of the hot hydrogen is 10-20% of the circulating hydrogen flow rate; the temperature of the hot hydrogen is 20-30°C higher than the temperature of the reaction product entering the hot high-pressure separator, and the stripping internals adopt 6-9 layers of sieve hole tower plates or floating valve tower plates; the inlet operating temperature of the dechlorination reactor is 250-300°C; the dechlorination agent, calculated by weight, includes 55-65 parts of calcium oxide, 8-12 parts of cerium oxide, 12-18 parts of magnesium oxide and 12-18 parts of diatomaceous earth.

9. The system for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil as claimed in claim 8, characterized in that: The preparation method of the dechlorinating agent comprises: weighing and mixing the components according to the raw material composition, adding 1-2% polyvinyl alcohol solution of the total mass of the raw materials, pressing and molding, calcining at 250-300°C for 1-2h, then heating to 500-550°C for calcining for 2-3h, crushing and screening the calcined product to obtain the dechlorinating agent.

10. A method for preparing bio-aviation fuel by hydrogenating waste tire pyrolysis oil, characterized in that: The method is applied to the system according to any one of claims 1 to 9, comprising the following steps: S1, filtering and preheating the waste tire pyrolysis oil, and then performing low-temperature hydrogenation treatment; S2, the low temperature hydrogenation effluent is subjected to secondary preheating and then to hydrofining reaction and shallow cracking reaction in sequence; S3, subjecting the cracking reaction product to hot high-pressure separation treatment to obtain a first gas phase and a first liquid phase, subjecting the first gas phase to a dechlorination reaction and then to cold high-pressure separation treatment to obtain a second gas phase, a first oil phase and a second liquid phase; S4, the first oil phase is subjected to cold low-pressure separation treatment to collect the second oil phase, the second gas phase enters the circulating hydrogen unit to obtain circulating hydrogen through desulfurization reaction, and the second liquid phase is discharged; the first liquid phase is subjected to hot low-pressure separation treatment to obtain a third gas phase and a third liquid phase, and the third gas phase is condensed and subjected to cold low-pressure separation treatment to collect the second oil phase; S5. The third liquid phase and the second oil phase are mixed and fractionated to obtain bio-aviation fuel and low-freezing-point biodiesel.

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