Hydrogenation method of waste tire pyrolytic oil

Abstract

The invention relates to the field of oil refining and chemical engineering, and discloses a hydrogenation method of waste tire pyrolytic oil. The method comprises the following steps: (1) in the presence of hydrogen, carrying out a gas-phase desulfurization reaction on a waste tire pyrolytic oil raw material in a gas-phase first hydrogenation reactor to obtain a gas-phase desulfurization reaction product; (2) carrying out gas-liquid separation on the gas-phase desulfurization reaction product to obtain a gas-phase component and a liquid-phase component; (3) carrying out pressurization and hydrogen mixing on the liquid-phase component, and then carrying out a liquid-phase dearomatization reaction in a second hydrogenation reactor to obtain a liquid-phase dearomatization reaction product; in the waste tire pyrolytic oil raw material, the content of N is 3000-10000 [mu] g / g. According to the method, the waste tire pyrolytic oil of the middle fraction is taken as a raw material, deep desulfurization is realized, removal of nitrides and monocyclic aromatic hydrocarbon saturation are reduced, the technological process is simplified on the whole, the reaction severity is reduced, and energy consumption and hydrogen consumption are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of oil refining and chemical engineering, and in particular to a hydrogenation method for waste tire pyrolysis oil. Background Art

[0002] As my country attaches great importance to environmental protection and resource recycling, the processing of waste tire pyrolysis oil has gradually become a hot topic. Waste tire pyrolysis is the decomposition of waste tires into pyrolysis gas, pyrolysis oil and pyrolysis char in a pyrolysis reactor. Among them, pyrolysis oil is rich in sulfides, nitrides, olefins, alkanes and aromatics, and its combustion calorific value is similar to that of diesel, so it is suitable for the production of automotive diesel products by the route of hydrorefining. However, the characteristic of waste tire pyrolysis oil is that the nitride content is high, even close to the sulfur content. This has caused great difficulties for hydrogenation desulfurization, because nitrides will seriously inhibit the desulfurization reaction, and nitrides must be removed first before effective desulfurization can be achieved. Nitrides not only inhibit desulfurization and dearomatization reactions to a great extent, but also cause waste of hydrogen resources due to their preferential hydrogenation.

[0003] From the perspective of the reaction mechanism of deep desulfurization and deep dearomatization, there are significant differences in the requirements for the reaction environment between the two. For desulfurization reactions, the removal of small molecular sulfur mainly follows the direct desulfurization route, that is, hydrogenation desulfurization. Large molecular sulfides with low reaction activity mainly follow the hydrodesulfurization reaction route, that is, first hydrogenation of the aromatic ring and then hydrogenation desulfurization. In the upper part of the reactor, the hydrogenation of small molecular sulfides and nitrides and the conversion of some bicyclic aromatic hydrocarbons (large heat release) mainly occur. In the lower part of the reactor, the accumulation of heat and hydrogen sulfide makes the reaction environment high temperature and low hydrogen partial pressure. This reaction environment is not conducive to the hydrodesulfurization path of large molecular sulfur and the saturation of polycyclic aromatic hydrocarbons. Especially at the end of the reaction, the catalyst activity decays. Raising the temperature can make up for the loss of desulfurization activity of the catalyst, but it will further affect the dearomatization effect. In addition to the different requirements for the reaction environment between the two, the competitive adsorption of aromatics on the catalyst surface also inhibits deep desulfurization, making it difficult for traditional hydrogenation technology to take into account the dual requirements of ultra-deep desulfurization and efficient saturation of aromatics. In addition, diesel only limits the content of polycyclic aromatic hydrocarbons, but during the hydrogenation reaction, some monocyclic aromatic hydrocarbons will undergo hydrogenation saturation reaction, further causing the problem of hydrogen waste. Based on the above two aspects, the necessity and urgency of upgrading diesel cleaning technology have become more prominent.

[0004] The existing technology can use a two-stage process to achieve deep dearomatization. After conventional hydrogenation, the generated oil is stripped to remove hydrogen sulfide and then enters the precious metal hydrogenation reactor. This will greatly increase the cost of catalyst use and the complexity of the process, and cannot solve the waste of hydrogen consumption caused by excessive hydrogenation. The crude oil can also be cut into light and heavy components. The light component is shallowly hydrogenated to avoid saturation of monocyclic aromatics as much as possible, and the heavy component is deeply hydrogenated for desulfurization and dearomatization. However, shallow hydrogenation generally uses medium-pressure hydrogenation, which increases the energy consumption of the entire technology and has not been industrialized.

[0005] Patent application CN108085058A discloses a method for deep dearomatization of hydrocarbon oil. The method uses relatively mild temperature and pressure conditions to make the crude oil and hydrogen pass through a highly dispersed Pt-Pd / Al2O3 catalyst, and the gas phase after the reaction is compressed and recycled, and the liquid phase is a low-aromatic product. However, the Pt-Pd / Al2O3 hydrogenation catalyst is mainly suitable for dearomatization of low-sulfur diesel raw materials, and the effect of desulfurization and dearomatization on low-quality diesel is not ideal.

[0006] Patent application CN109926067A discloses a platinum-palladium-cobalt ternary metal hydrogenation dearomatization catalyst and its preparation method. The method adopts a step-by-step impregnation method of active metal precursors, so that the utilization rate of the prepared catalyst platinum palladium precious metal is high, the synergistic catalytic ability is strong, and the introduction of platinum palladium leads to the enhancement of the aromatic hydrogenation performance of non-precious metal cobalt. However, the catalyst is still aimed at hydrocarbon oil after the sulfur-containing compounds have been basically removed to avoid the influence of hydrogen sulfide on the deep dearomatization of precious metals, and cannot achieve the desulfurization and dearomatization of inferior diesel. Summary of the invention

[0007] The purpose of the present invention is to overcome the technical problems existing in the prior art and provide a method for hydrogenating waste tire pyrolysis oil. The method uses the middle fraction of waste tire pyrolysis oil as a raw material, reduces the removal of nitrides and the saturation of monocyclic aromatic hydrocarbons while deeply desulfurizing, and also simplifies the process flow as a whole, reduces the severity of the reaction, and reduces energy consumption and hydrogen consumption.

[0008] In order to achieve the above object, the present invention provides a method for hydrogenating waste tire pyrolysis oil, wherein the method comprises the following steps: (1) in the presence of hydrogen, subjecting the waste tire pyrolysis oil raw material to a gas phase desulfurization reaction in a gas phase first hydrogenation reactor to obtain a gas phase desulfurization reaction product; (2) separating the gas-phase desulfurization reaction product into gas-liquid components to obtain a gas-phase component and a liquid-phase component; (3) pressurizing and hydrogenating the liquid phase components, and then performing a liquid phase dearomatization reaction in a second hydrogenation reactor to obtain a liquid phase dearomatization reaction product; The N content of the waste tire pyrolysis oil raw material is 3000-10000 μg / g.

[0009] Compared with the prior art, the method of the present invention has the following advantages: The method of the present invention avoids the defect that deep desulfurization and dearomatization are placed in the same reaction system and the reaction conditions are difficult to be compatible. The inventors have found that, preferably, by controlling the reaction conditions of the first hydrogenation reactor, only the hydrogenation removal reaction of sulfides occurs in the first hydrogenation reactor, thereby separating the desulfurization and dearomatization reactions, optimizing the reaction conditions respectively, and improving the efficiency of each reaction.

[0010] The method provided by the present invention can reduce the hydrogen consumption of the reaction, and can also reduce the hydrogen-oil volume ratio of the gas phase hydrogenation reaction and reduce the severity of the reaction.

[0011] The method provided by the present invention is particularly suitable for the hydrogenation reaction of waste tire pyrolysis oil with a high nitrogen content. While the gas-phase hydrodesulfurization reaction realizes gas-phase desulfurization, nitrides are difficult to undergo hydrogenation reaction, and enter the gas-phase components in large quantities through gas-liquid separation without undergoing deep hydrogenation, thereby achieving a reduction in hydrogen consumption in the chemical reaction, which is more conducive to subsequent deep dearomatization; for waste tire pyrolysis oil with a high nitrogen content, the reduction in hydrogen consumption is greater.

[0012] The method provided by the present invention can supplement hydrogen consumed in the liquid phase dearomatization reaction while increasing the pressure, and the hydrogen can be used without recycling, thus eliminating the need for a circulating hydrogen compressor and greatly reducing the investment in device construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the process flow of the present invention.

[0014] Reference numerals DETAILED DESCRIPTION The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0015] The description of the exemplary embodiments is intended to be read in conjunction with the accompanying drawings, which are considered a part of the entire written description. In the specification, relative terms such as "lower", "upper", "horizontal", "vertical", "above", "below", "upward", "downward", "top" and "bottom" and their derivatives (for example, "horizontally", "downwardly", "upwardly", etc.) should be interpreted as the directions shown in the drawings being described at the time. These relative terms are for convenience of description and do not require that the device be constructed or operated in a particular orientation. Unless otherwise specified, "connected" as used herein refers to a relationship whereby structures are directly or indirectly fixed or connected to each other through intermediate structures.

[0016] In the present invention, the symbol “≯” indicates not greater than, and the symbol “≮” indicates not less than.

[0017] The present invention provides a method for hydrogenating waste tire pyrolysis oil, wherein the method comprises the following steps: (1) in the presence of hydrogen, subjecting the waste tire pyrolysis oil raw material to a gas phase desulfurization reaction in a first hydrogenation reactor to obtain a gas phase desulfurization reaction product; (2) separating the gas-phase desulfurization reaction product into gas-liquid components to obtain a gas-phase component and a liquid-phase component; (3) pressurizing and hydrogenating the liquid phase components, and then performing a liquid phase dearomatization reaction in a second hydrogenation reactor to obtain a liquid phase dearomatization reaction product; The N content of the waste tire pyrolysis oil raw material is 3000-10000 μg / g.

[0018] According to the method provided by the present invention, the waste tire pyrolysis oil raw material undergoes a gas phase desulfurization reaction in a first hydrogenation reactor, the gas phase desulfurization reaction mainly removes small molecular sulfides and does not remove nitrides, and the liquid phase component obtained by gas-liquid separation of the gas phase desulfurization reaction product enters the second hydrogenation reactor after pressurization and hydrogen mixing to undergo a deep hydrogenation dearomatization reaction. The method provided by the present invention is applicable to any substance that needs to remove small molecular sulfides and large molecular aromatics at the same time.

[0019] The present invention realizes deep desulfurization and dearomatization of crude oil under milder operating conditions and a simpler process flow.

[0020] In the present invention, the hydrogen in step (1) can be any hydrogen-containing gas that can provide hydrogen, which can be fresh hydrogen, recycled hydrogen, or hydrogen-rich gas. Those skilled in the art can clearly understand the hydrogen-containing gas described in the present invention after understanding the technical solution of the present invention.

[0021] In the present invention, the waste tire pyrolysis oil refers to the diesel fraction cut out of the pyrolysis oil component obtained after the waste tire is subjected to the pyrolysis process. The present invention does not specifically limit the specific operation mode and means of its pyrolysis process, and those skilled in the art can select according to actual needs.

[0022] In the present invention, the properties of waste tire pyrolysis oil can be selected in a wide range. Preferably, in step (1), the initial boiling point of the waste tire pyrolysis oil raw material is 130-180°C, the final boiling point is 320-350°C, the S content is ≯15000μg / g, preferably ≯11000μg / g, the N content is 5000-10000μg / g, and the polycyclic aromatic hydrocarbon content is ≯50wt%. For example, the S content of the waste tire pyrolysis oil can be exemplified but not limited to: 8000 μg / g, 9000 μg / g, 10000 μg / g, 11000 μg / g, etc., the N content can be exemplified but not limited to: 5000 μg / g, 6000 μg / g, 7000 μg / g, 8000 μg / g, 9000 μg / g, 10000 μg / g, etc., and the polycyclic aromatic hydrocarbon content can be exemplified but not limited to: 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, etc.

[0023] In the present invention, preferably, in step (1), based on the waste tire pyrolysis oil raw material, the sulfur content in the gas phase desulfurization reaction product is 1-30wt%, preferably 4-20wt%, for example, it can be 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt% and values ​​between any two groups. Since the aromatic rings of macromolecular sulfides cannot be hydrogenated under low pressure conditions, they are more likely to be removed by hydrogenation desulfurization pathways to reduce hydrogen consumption in chemical reactions. For macromolecular sulfides of the sterically hindered 4,6-DMDBT type, they can be deeply removed in a subsequent hydrogenation unit. In the present invention, the sulfur content in the gas phase desulfurization reaction product is within the above range, which has the characteristics of high hydrogenation selectivity.

[0024] In the present invention, the conditions for the gas phase desulfurization reaction in the first hydrogenation reactor can be selected in a wide range, as long as the removal of gas phase small molecular sulfur is achieved. Preferably, in step (1), the conditions for the gas phase desulfurization reaction include: a pressure of 0.5-3 MPa, a temperature of 300-400°C, a hydrogen-to-oil volume ratio of 50-500, and a volume space velocity of 0.5-3 h -1 Further preferably, in step (1), the conditions of the gas phase desulfurization reaction include: pressure of 1-2 MPa, temperature of 320-380°C, hydrogen-to-oil volume ratio of 150-300, volume space velocity of 1-2 h -1 .

[0025] In the present invention, by controlling the reaction conditions of the gas phase desulfurization reaction, gas phase desulfurization is achieved while better coordination with the subsequent liquid phase hydrogenation reaction is performed, thereby being more conducive to the subsequent deep dearomatization. In addition, the preferred gas phase desulfurization reaction conditions of the present invention avoid the hydrogenation saturation of macromolecular nitrides and reduce hydrogen consumption. Macromolecular nitrides are mostly structures containing aromatic rings and nitrogen heterocycles, and the CN bond can only be broken after the aromatic rings and nitrogen heterocycles are completely hydrogenated and saturated. Under the reaction conditions of the gas phase hydrodesulfurization reaction, macromolecular nitrides are difficult to undergo hydrogenation reactions, and enter the gas phase components in large quantities through gas-liquid separation without deep hydrogenation, thereby achieving a reduction in hydrogen consumption in chemical reactions.

[0026] In the present invention, the first hydrogenation reactor is loaded with a hydrogenation catalyst having a desulfurization function. The present invention does not particularly limit the type of the first hydrogenation catalyst, and those skilled in the art can select it according to actual needs. Preferably, in step (1), the gas phase desulfurization reaction is carried out in the presence of a first hydrogenation catalyst, and the first hydrogenation catalyst includes a carrier and a hydrogenation component.

[0027] In the present invention, the carrier has a wide range of choices. Preferably, the carrier is an inorganic refractory oxide, and the inorganic refractory oxide is selected from at least one of alumina, amorphous silica-alumina, silicon dioxide and titanium oxide, and more preferably alumina.

[0028] In the present invention, the selection range of the hydrogenation component is relatively wide. Preferably, the hydrogenation component includes a Group VIII metal component and / or a Group VIB metal component. In the present invention, the specific types of the Group VIII metal and the Group VIB metal are not limited, and those skilled in the art can select according to actual needs.

[0029] In the present invention, preferably, the first hydrogenation catalyst is a Mo-Co type hydrodesulfurization catalyst.

[0030] In the present invention, there is no particular limitation on the content of each component in the Mo-Co type hydrodesulfurization catalyst. Preferably, based on the total amount of the Mo-Co type hydrodesulfurization catalyst, the content of Mo in terms of oxide is 15-30wt%, and the content of Co in terms of oxide is 2-6wt%.

[0031] In the present invention, preferably, the Mo-Co type hydrodesulfurization catalyst further comprises an auxiliary component, and the auxiliary component is selected from at least one of phosphorus, silicon, boron, magnesium and fluorine. Preferably, the content of the auxiliary component calculated as oxide is 6wt% or less.

[0032] In the present invention, there is no limitation on the source of the first hydrogenation catalyst, for example, it can be prepared by any method conventionally defined in the art, or it can be commercially available, for example, it can be FHUDS-5 and / or FHUDS-7 catalyst developed by Fushun Research Institute of Petrochemical Industry (FRIPP) of Sinopec.

[0033] According to the method provided by the present invention, by matching the use of a high hydrogenation desulfurization path catalyst in the first hydrogenation reactor, the desulfurization reaction is controlled to follow a reaction path with low hydrogen consumption, thereby reducing the chemical hydrogen consumption of the desulfurization reaction. At the same time, the hydrogen-to-oil volume ratio of the first hydrogenation reactor can also be reduced, thereby reducing the severity of the reaction.

[0034] The present invention uses a small amount of heat exchange under high temperature conditions for the gas phase desulfurization reaction product, retains a large amount of reaction heat under the condition of ensuring that the macromolecules are liquefied, meets the feeding conditions of the second hydrogenation reactor, and saves energy consumption. In the present invention, preferably, the method also includes heat exchange and cooling the gas phase desulfurization reaction product before performing the gas-liquid separation.

[0035] The invention has no particular limitation on the heat exchange conditions, and preferably can ensure the liquefaction of the macromolecular heavy substances in the gas phase desulfurization reaction product. The invention also has no particular limitation on the specific operation of the heat exchange, and any heat exchange medium conventionally used in the art can be used for the operation. The heat exchange can be carried out in a heat exchange unit such as a heat exchanger, and the invention has no particular limitation on the specific type of the heat exchanger, for example, it can be a commercial heat exchanger conventionally defined in the art, or it can be a tubular heat exchanger.

[0036] In the present invention, preferably, based on the total amount of the gas phase desulfurization reaction product, the mass percentage of the liquid phase component is 20-40%. This preferred embodiment is more conducive to accurately controlling the liquefaction ratio, specifically hydrogenating the heavy components, and reducing chemical hydrogen consumption.

[0037] In the present invention, a hydrogenation catalyst having a dearomatization function is loaded in the liquid phase hydrogenation reactor, and the present invention has a wide range of selection of types of the hydrogenation dearomatization catalyst. Preferably, in step (3), the liquid phase dearomatization reaction is carried out in the presence of a hydrogenation dearomatization catalyst, and the hydrogenation dearomatization catalyst is a non-precious metal catalyst and / or a precious metal catalyst.

[0038] In the present invention, the non-precious metal catalyst may include a carrier and a hydrogenation active metal, wherein the carrier is an inorganic refractory oxide, generally selected from at least one of alumina, amorphous silica-alumina, silica and titanium oxide, preferably alumina; the hydrogenation active metal includes a VIB group metal component and / or a VIII group metal component. Preferably, in the hydrodearomatization catalyst, the VIB group metal component is preferably selected from tungsten and / or molybdenum, and the VIII group metal component is preferably selected from nickel and / or cobalt; preferably, the hydrodearomatization catalyst may also contain an auxiliary component, such as at least one of phosphorus, silicon, boron, magnesium and fluorine, and the mass content in the hydrodearomatization catalyst is generally below 6wt%. Preferably, the non-precious metal catalyst is a Mo-Ni type hydrodearomatization catalyst.

[0039] In the present invention, preferably, based on the total amount of the Mo-Ni type hydrodearomatization catalyst, the content of Mo calculated as oxide is 15-30wt%, and the content of Ni calculated as oxide is 2-5wt%.

[0040] In the present invention, there is no particular limitation on the source of the hydrodearomatization catalyst, and the catalyst may be prepared by any method or purchased commercially, and may be at least one of FHUDS-10, FHUDS-6 and FHUDS-8 developed by Fushun Research Institute of Petrochemical Industry (FRIPP) of Sinopec.

[0041] In the present invention, the noble metal catalyst preferably uses Pt, Pd or the like as the active metal, which can also be prepared by any method or can be a commercially available catalyst, such as the FHDA-10 catalyst developed by Fushun Research Institute of Petrochemicals (FRIPP) of Sinopec.

[0042] In the present invention, the liquid phase dearomatization reaction conditions can be selected in a wide range. Preferably, in step (3), the liquid phase dearomatization reaction conditions include: a pressure of 2-8 MPa, a temperature of 200-400°C, a volume space velocity of 0.2-5 h -1 Further preferably, in step (3), the conditions of the liquid phase dearomatization reaction include: pressure of 3-6 MPa, temperature of 260-345°C, volume space velocity of 0.2-0.5 h -1 .

[0043] In the present invention, in step (3), the specific operation and condition selection range for pressurizing and hydrogen mixing the liquid phase component is relatively wide. The pressurization and hydrogen mixing are used to supplement the hydrogen required for the reaction on the basis of pressurizing the liquid phase component. It is preferred to pressurize and hydrogen mix until the reaction conditions and hydrogen consumption requirements in the liquid phase hydrogenation reactor are met. In the present invention, there is no special limitation on the specific operation mode of pressurization and hydrogen mixing. The specific process may be that the liquid phase component is first pressurized by a pressurization unit, and then enters the hydrogen mixing unit, and the hydrogen is pressurized by a compressor (pressurization unit) to a pressure slightly higher than that of the liquid phase component (higher than the liquid phase component by 0.05-0.1MPa), and also enters the hydrogen mixing unit. The material flowing out of the hydrogen mixing unit is a liquid phase component dissolved with hydrogen.

[0044] In the present invention, the pressurization and hydrogen mixing in step (3) can be carried out in any unit that can achieve pressurization and hydrogen mixing. For example, the pressurization and hydrogen mixing can be carried out in a pressurization unit and a hydrogen mixing unit respectively. There is no particular limitation on the types of the pressurization unit and the hydrogen mixing unit, as long as the pressurization and hydrogen mixing of the liquid phase components can be achieved.

[0045] In the present invention, preferably, the boosting unit is a gas phase booster.

[0046] In the present invention, preferably, the hydrogen mixing unit is selected from at least one of a membrane-tube hydrogen dissolving assembly, a hydrogen mixer (for example, a high-efficiency hydrogen mixer), a microbubble generator, and a bubble fractalizer. For example, a hydrogen mixer with strong convection backmixing or a hydrogen mixer with micropores to generate microbubbles is used to increase solubility. Preferably, the hydrogen mixer is provided with a support plate with uniformly distributed pores and downcomers to improve gas phase dispersion.

[0047] In the present invention, preferably, during the hydrogen mixing process in step (3), relative to 1m 3 The liquid phase component, the hydrogen replenishment amount is 10-40Nm 3 , further preferably 20-30Nm 3 .

[0048] In the present invention, preferably, the pressure of the liquid phase dearomatization reaction is at least 1 MPa higher than the pressure of the gas phase desulfurization reaction, preferably 2-5 MPa higher. The method provided by the present invention performs the reaction at low pressure, greatly reducing the severity of the reaction and saving energy consumption.

[0049] In the present invention, preferably, the temperature of the liquid phase dearomatization reaction is at least 15° C. lower than that of the gas phase desulfurization reaction, preferably 20-40° C. lower. The method provided by the present invention is more conducive to liquefying macromolecules that need further reaction and retaining reaction heat.

[0050] In the present invention, there is no particular limitation on the application of the gas phase component (also referred to as hydrogenation light component) and the liquid phase hydrogenation reaction product obtained by gas-liquid separation, and they can be adaptively treated according to the specific needs of the product. Preferably, the method further comprises mixing the gas phase component and the liquid phase dearomatization reaction product of step (2) and then subjecting them to dehydrogensulfide treatment. The gas phase component and the liquid phase dearomatization reaction product can be treated separately or together, preferably together. According to a preferred embodiment of the present invention, the method further comprises mixing the gas phase component and the liquid phase dearomatization reaction product of step (2) and then subjecting them to dehydrosulfide treatment to obtain a waste tire pyrolysis oil product. The present invention does not particularly limit the specific operation and conditions of the dehydrosulfide treatment, and it can be carried out according to conventional technical means in the art, preferably by steam stripping. The steam stripping can be carried out in a steam stripping unit such as a stripping tower.

[0051] In the present invention, preferably, the content of aromatics in the waste tire pyrolysis oil product is less than 5wt%, and the content of S is less than 10μg / g.

[0052] In the present invention, there is no particular limitation on the types of the first hydrogenation reactor and the second hydrogenation reactor. Preferably, the first hydrogenation reactor and the second hydrogenation reactor are each independently a fixed bed reactor.

[0053] According to a specific embodiment of the present invention, the aforementioned method of the present invention is as follows Figure 1 In the system shown, the waste tire pyrolysis oil raw material and hydrogen 1 enter the first hydrogenation reactor 2 for gas phase desulfurization reaction to obtain a gas phase desulfurization reaction product 3. The gas phase desulfurization reaction product 3 enters the heat exchange unit 4 for heat exchange and cooling, and then enters the gas-liquid separation unit 5 for gas-liquid separation to obtain a gas phase component 7 and a liquid phase component 6. The liquid phase component 6 is pressurized by the pressurization and hydrogen mixing unit 8 and enters the second hydrogenation reactor 9 for liquid phase dearomatization reaction to obtain a liquid phase dearomatization reaction product 10. The gas phase component 7 and the liquid phase dearomatization reaction product 10 are mixed and then sent to the stripping unit 11 for stripping to obtain a waste tire pyrolysis oil product 12.

[0054] The present invention will be described in detail below through examples.

[0055] In the following examples and comparative examples, chemical hydrogen consumption refers to the mass percentage of hydrogen consumed per unit mass of raw material.

[0056] In the present invention, unless otherwise explicitly stated, percentages and contents are all based on mass.

[0057] Combine the following Figure 1The method and system of the present invention are described in detail. The waste tire pyrolysis oil raw material and hydrogen 1 enter the first hydrogenation reactor 2, a gas phase desulfurization reaction occurs, and a gas phase desulfurization reaction product 3 is obtained; enter the heat exchange unit 4 (heat exchanger), and after cooling by the heat exchanger, enter the gas-liquid separation unit 5 (gas-liquid separator) to obtain a liquid phase component 6 and a gas phase component 7. The gas phase component 7 is discharged upward from the gas-liquid separator, and the liquid phase component 6 is discharged downward from the gas-liquid separator, and then enters the second hydrogenation reactor 9 through the pressurization and hydrogen mixing unit 8 for liquid phase hydrogenation reaction to obtain a liquid phase dearomatization reaction product 10, and the gas phase component 7 and the liquid phase dearomatization reaction product 10 are mixed and enter the stripping unit 11 (stripping tower), and finally a waste tire pyrolysis oil product 12 is obtained.

[0058] Examples 1-3 Use Figure 1 Schematic diagram of the process. Two 100mL fixed-bed hydrogenation reactors are connected in series, namely the first hydrogenation reactor and the second hydrogenation reactor. A heat exchanger, a gas-liquid separator, a supercharger and a hydrogen mixer are set between the reactors. The first hydrogenation reactor is filled with 50mL Mo-Co type hydrogenation catalyst A, and the second hydrogenation reactor is filled with 50mL Mo-Ni type hydrogenation catalyst B. A gas phase outlet is set above the gas-liquid separator, which is connected to the bottom effluent of the second hydrogenation reactor and enters the stripping tower together to obtain the waste tire pyrolysis oil product.

[0059] The middle fraction of waste tire pyrolysis oil was used as raw material. The catalyst properties are shown in Table 1, the raw oil properties are shown in Table 2, and the reaction process conditions and results are shown in Table 3.

[0060] Example 4 The same process flow as in Example 1-3 was used, except that the separation conditions for gas-liquid separation were changed. The properties of the catalyst are shown in Table 1, the properties of the feedstock oil are shown in Table 2, and the reaction process conditions and results are shown in Table 3.

[0061] Comparative Example 1 The conventional diesel fixed bed hydrogenation process was adopted, and two hydrogenation reactors were set in series, namely the first hydrogenation reactor and the second hydrogenation reactor, and a stripping tower was set between the two reactors to remove hydrogen sulfide. The first hydrogenation reactor was filled with 50mL Mo-Co type hydrogenation catalyst A, and the second hydrogenation reactor was filled with 50mL Mo-Ni type hydrogenation catalyst B. After the reactor, high-fraction, low-fraction, stripping and other processes were conventionally set to obtain waste tire pyrolysis oil products. After removing hydrogen sulfide, hydrogen was pressurized and recycled by a circulating hydrogen compressor. The raw materials and catalyst properties are the same as those in Example 1-3, and the reaction process conditions and results are shown in Table 3.

[0062] Comparative Example 2 The same process flow as in Example 1-3 was adopted, except that the hydrogen-to-oil volume ratio at the inlet of the first hydrogenation reactor was increased, the hydrogen mixer before the second hydrogenation reactor was cancelled, and only a liquid phase booster pump was used. The first hydrogenation reactor was filled with 50 mL of Mo-Co type hydrogenation catalyst A, and the second hydrogenation reactor was filled with 50 mL of Mo-Ni type hydrogenation catalyst B. The raw materials and catalyst properties were the same as in Example 1-3, and the reaction process conditions and results are shown in Table 3.

[0063] Table 1 Table 2 Table 3 Note: In Table 3, the amount of hydrogen replenished refers to the amount relative to 1m 3 The amount of hydrogen required for the liquid phase component.

[0064] As can be seen from Table 3, Comparative Example 1 adopts conventional fixed bed hydrogenation technology and traditional catalyst loading system, and the pressure of the first hydrogenation reactor is relatively high, resulting in desulfurization, denitrogenation and dearomatization occurring simultaneously and affecting each other, and the reaction conditions cannot be optimized for a certain reaction, resulting in poor reaction effect and high hydrogen consumption, hydrogen recycling, and high energy consumption. However, under the premise that the pressure of the first hydrogenation reactor is significantly reduced, the reaction system of the present invention divides desulfurization and dearomatization and denitrogenation into two reaction systems, optimizes the reaction conditions in a targeted manner, obtains better dearomatization effect, and better retains nitrides that do not need hydrogenation, avoids the restriction of nitrides on hydrogenation reaction, and improves reaction efficiency; sulfides are removed through the hydrogenolysis path, and nitrides are hydrogenated in small amounts, reducing hydrogen consumption; hydrogen does not need to be recycled, reducing energy consumption.

[0065] In Comparative Example 2, no hydrogen mixer is provided before the liquid phase reactor, and sufficient hydrogen source is provided by increasing the hydrogen-to-oil volume ratio at the inlet of the first hydrogenation reactor. However, the high hydrogen-to-oil volume ratio of the first hydrogenation reactor will lead to low oil phase partial pressure in the separator and insufficient liquefaction, that is, it is difficult for all polycyclic aromatic hydrocarbons to enter the liquid phase component for liquid phase hydrogenation reaction, resulting in a high content of polycyclic aromatic hydrocarbons in the refined oil. In addition, a compressor is required for hydrogen circulation, and the energy consumption is still higher than that of the embodiment.

[0066] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for hydrogenating waste tire pyrolysis oil, characterized in that: The method comprises the following steps: (1) in the presence of hydrogen, subjecting the waste tire pyrolysis oil raw material to a gas phase desulfurization reaction in a first hydrogenation reactor to obtain a gas phase desulfurization reaction product; (2) separating the gas-phase desulfurization reaction product into gas-liquid components to obtain a gas-phase component and a liquid-phase component; (3) pressurizing and hydrogenating the liquid phase components, and then performing a liquid phase dearomatization reaction in a second hydrogenation reactor to obtain a liquid phase dearomatization reaction product; The N content of the waste tire pyrolysis oil raw material is 3000-10000 μg / g.

2. The method according to claim 1, wherein: In step (1), the initial distillation point of the waste tire pyrolysis oil raw material is 130-180°C, the final distillation point is 320-350°C, the S content is ≯15000 μg / g, preferably ≯11000 μg / g, the N content is 5000-10000 μg / g, and the polycyclic aromatic hydrocarbon content is ≯50wt%.

3. The method according to claim 1 or 2, wherein: In step (1), based on the waste tire pyrolysis oil raw material, the sulfur content in the gas phase desulfurization reaction product is 1-30wt%, preferably 4-20wt%; Preferably, in step (1), the conditions of the gas phase desulfurization reaction include: pressure of 0.5-3 MPa, temperature of 300-400°C, hydrogen-to-oil volume ratio of 50-500, volume space velocity of 0.5-3 h -1 ; Preferably, in step (1), the conditions for the gas phase desulfurization reaction include: pressure of 1-2 MPa, temperature of 320-380°C, hydrogen-to-oil volume ratio of 150-300, volume space velocity of 1-2 h -1 .

4. The method according to any one of claims 1 to 3, wherein: In step (1), the gas phase desulfurization reaction is carried out in the presence of a first hydrogenation catalyst, wherein the first hydrogenation catalyst comprises a carrier and a hydrogenation component; Preferably, the carrier is an inorganic refractory oxide, and the inorganic refractory oxide is selected from at least one of alumina, amorphous silica-alumina, silicon dioxide and titanium oxide; Preferably, the hydrogenation component comprises a Group VIII metal component and / or a Group VIB metal component; Preferably, the first hydrogenation catalyst is a Mo-Co type hydrodesulfurization catalyst; Preferably, based on the total amount of the Mo-Co type hydrodesulfurization catalyst, the content of Mo calculated as oxide is 15-30wt%, and the content of Co calculated as oxide is 2-6wt%.

5. The method according to any one of claims 1 to 4, wherein: The method further comprises, before performing the gas-liquid separation, subjecting the gas-phase desulfurization reaction product to heat exchange and cooling; Preferably, based on the total amount of the gas phase desulfurization reaction product, the mass percentage of the liquid phase component is 20-40%.

6. The method according to any one of claims 1 to 5, wherein: In step (3), the liquid phase dearomatization reaction is carried out in the presence of a second hydrogenation catalyst, and the second hydrogenation catalyst is a non-precious metal catalyst and / or a precious metal catalyst; Preferably, the non-precious metal catalyst is a Mo-Ni type hydrodearomatization catalyst; Preferably, based on the total amount of the Mo-Ni type hydrodearomatization catalyst, the content of Mo calculated as oxide is 15-30wt%, and the content of Ni calculated as oxide is 2-5wt%.

7. The method according to any one of claims 1 to 6, wherein: In step (3), the conditions of the liquid phase dearomatization reaction include: pressure of 2-8 MPa, temperature of 200-400°C, volume space velocity of 0.2-5 h -1 ; Preferably, in step (3), the conditions of the liquid phase dearomatization reaction include: pressure of 3-6 MPa, temperature of 260-345°C, volume space velocity of 0.2-0.5 h -1 .

8. The method according to any one of claims 1 to 7, wherein: During the hydrogen mixing process in step (3), relative to 1m 3 The liquid phase component, the hydrogen replenishment amount is 10-40Nm 3 , preferably 20-30Nm 3 ; Preferably, the pressure of the liquid phase dearomatization reaction is at least 1 MPa higher than the pressure of the gas phase desulfurization reaction, preferably 2-5 MPa higher; Preferably, the temperature of the liquid phase dearomatization reaction is at least 15°C lower than the temperature of the gas phase desulfurization reaction, preferably 20-40°C lower.

9. The method according to any one of claims 1 to 8, wherein: The method further comprises mixing the gas phase component in step (2) with the liquid phase dearomatization reaction product and then performing a dehydrogen sulfide treatment to obtain a waste tire pyrolysis oil product; Preferably, the waste tire pyrolysis oil product has an aromatic content of less than 5 wt% and an S content of less than 10 μg / g.

10. The method according to any one of claims 1 to 9, wherein: The first hydrogenation reactor and the second hydrogenation reactor are each independently a fixed bed reactor.

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