Process for the production of high smoke point jet fuel products

Abstract

The present application relates to the chemical industry field, disclose a kind of high smoke point aviation kerosene product production method.The method includes the following steps: (1) in the presence of hydrogen, aviation kerosene raw material is carried out gas phase desulfurization reaction in hydrogenation desulfurization reactor, obtain gas phase desulfurization reaction product;(2) the gas-liquid separation of gas phase desulfurization reaction product is obtained gas phase component and liquid phase component, with the total amount of gas phase desulfurization reaction product, the mass percentage content of liquid phase component is 15-50%;(3) the liquid phase component is pressurized, then in hydrogenation dearomatization reactor is carried out liquid phase dearomatization reaction, obtain liquid phase dearomatization reaction product;Wherein, the smoke point of aviation kerosene raw material is 16-22mm.The method has more moderate process conditions with aviation kerosene as raw material, produce high smoke point aviation kerosene product, also improve chemical reaction efficiency, reduce energy consumption and hydrogen consumption.

Description

Technical Field

[0001] This invention relates to the chemical industry, specifically to a method for producing high smoke point jet fuel. Background Technology

[0002] In recent years, China's civil aviation industry has continued to develop, leading to a growing demand for aviation fuel. On the other hand, with the adjustment of China's energy structure, the demand for diesel fuel has slowed down year by year, and reducing the diesel-to-gasoline ratio has become an overall trend in refining structure adjustment. Slicing aviation kerosene into heavier fractions, i.e., increasing the final boiling point of aviation kerosene and incorporating more diesel components, can increase aviation kerosene yield and reduce diesel production, effectively addressing the current problem of surging aviation kerosene demand and declining diesel demand. However, as the aviation kerosene fractions become heavier, some aromatics from diesel fuel return to the aviation kerosene fractions. This increase in aromatics content in aviation kerosene can lead to substandard smoke point indicators in the aviation kerosene product. Existing aviation kerosene units have relatively low pressure design levels, typically 3-4 MPa, while aromatics hydrogenation in a fixed-bed reaction environment requires higher reaction pressures. Existing units cannot effectively remove aromatics using pressurization methods, thus failing to significantly improve smoke point indicators. Therefore, to achieve the production of high smoke point aviation kerosene products through heavy fractionation, it is necessary to increase the unit pressure, resulting in energy waste.

[0003] However, from the perspective of the desulfurization and dearomatization reaction mechanisms in jet fuel fractions, the requirements for the reaction environment differ significantly. For desulfurization reactions, the removal of small-molecule thiols and thioethers mainly follows the direct desulfurization route, i.e., hydrodesulfurization. High reaction pressure is not required. Aromatics, on the other hand, are mainly concentrated in the heavier components after debinding; simply applying pressure to these heavier components for dearomatization is sufficient. If a highly active hydrogenation catalyst is used under high-pressure reaction conditions, and desulfurization and dearomatization reactions occur simultaneously, the desulfurization depth will be significantly increased, leading to poorer lubricity of the refined jet fuel. Simultaneously, some thiophene sulfides will be removed under high pressure via the hydrogenation pathway, increasing chemical hydrogen consumption. Furthermore, the hydrogen sulfide generated during the desulfurization process will affect hydrodearomatization, lowering the hydrogen partial pressure and resulting in a lower concentration of aromatics in the mixed components, both of which are detrimental to efficient dearomatization reactions.

[0004] Patent application CN107233927A discloses a medium-oil type hydrocracking catalyst and its preparation method. This method uses a modified β-molecular sieve with relatively balanced cracking performance, resulting in middle distillate oil with the high smoke point characteristic of jet fuel. However, the conventional fixed-bed hydrocracking process used to produce jet fuel with this catalyst suffers from drawbacks such as high hydrogen and energy consumption and low jet fuel yield.

[0005] Patent application CN111088072A discloses a hydrocracking method for reducing the bromine index of heavy naphtha and increasing the smoke point of jet fuel. This method involves fractionating the hydrorefined and hydrocracking oil products, resulting in a light jet fuel component rich in aromatics, which is recycled back to the hydrocracking unit. The component rich in alkanes obtained from the fractionation is used as the jet fuel product. However, this method produces a low jet fuel yield, consumes a large amount of energy during production, and the product contains a high content of alkanes, which can easily lead to product defects. Summary of the Invention

[0006] The purpose of this invention is to overcome the technical problem in the prior art where the removal of sulfides and aromatics in aviation kerosene fractions is carried out in the same reaction system, leading to excessive hydrogenation. This invention provides a method for producing high smoke point aviation kerosene products. This method uses aviation kerosene as raw material under more moderate process conditions to produce high smoke point aviation kerosene products, while also improving chemical reaction efficiency and reducing energy and hydrogen consumption.

[0007] To achieve the above objectives, the present invention provides a method for producing high smoke point aviation kerosene, wherein the method includes the following steps:

[0008] (1) In the presence of hydrogen, jet fuel is subjected to gas-phase desulfurization reaction in a hydrodesulfurization reactor to obtain gas-phase desulfurization reaction products;

[0009] (2) The gas phase desulfurization reaction products are subjected to gas-liquid separation to obtain gas phase components and liquid phase components. The total amount of the gas phase desulfurization reaction products shall be used as the standard, and the mass percentage of the liquid phase components shall be 15-50%.

[0010] (3) The liquid phase component is pressurized and then subjected to a liquid phase dearomatization reaction in a hydrodearomatization reactor to obtain the liquid phase dearomatization reaction product;

[0011] The smoke point of the jet fuel is 16-22 mm.

[0012] Compared with the prior art, the method of the present invention has the following advantages:

[0013] The method provided by this invention achieves desulfurization and aromatic removal from cut-weight jet fuel as raw material, producing high-smoke-point jet fuel products under more moderate operating conditions and a simplified process flow. This allows refineries to increase the final boiling point of jet fuel fractions, thereby increasing jet fuel production and meeting the demands for quality improvement and efficiency enhancement. In the hydrodesulfurization reactor, only low-hydrogen-consumption desulfurization reactions occur under low-pressure conditions, reducing hydrogen consumption. The liquid phase component after gas-liquid separation undergoes an aromatics hydrogenation saturation reaction after pressurization. The entire reaction system eliminates the need for a hydrogen compressor in a fixed-bed reaction system and a circulating oil pump in a liquid-phase hydrogenation reaction system, reducing investment costs, simplifying the process flow, improving reaction efficiency, and reducing reaction severity.

[0014] The hydrogen produced by this invention does not require recycling, eliminating the need for a circulating hydrogen compressor and significantly reducing investment in equipment construction. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the process flow according to an embodiment of the present invention.

[0016] Figure Labels

[0017] Detailed Implementation

[0018] The endpoints and any values ​​of the ranges disclosed herein 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 the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0019] The description of exemplary embodiments is intended to be read in conjunction with the accompanying drawings, which are considered an integral part of the entire written description. In this specification, relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “upward,” “downward,” “top,” and “bottom,” and their derivatives (e.g., “horizontally,” “downward,” “upward,” etc.) should be interpreted as referring to the orientation shown in the accompanying drawings as described at the time. These relative terms are for ease of description and do not require the device to be constructed or operated in a particular orientation. Unless otherwise stated, “connection” as used in this invention refers to a relationship in which structures are directly or indirectly fixed or connected to each other via an intermediate structure.

[0020] In this invention, the symbol “≯” indicates not greater than, and the symbol “≮” indicates not less than.

[0021] This invention provides a method for producing high smoke point aviation kerosene, wherein the method includes the following steps:

[0022] (1) In the presence of hydrogen, jet fuel is subjected to gas-phase desulfurization reaction in a hydrodesulfurization reactor to obtain gas-phase desulfurization reaction products;

[0023] (2) The gas phase desulfurization reaction products are subjected to gas-liquid separation to obtain gas phase components and liquid phase components. The total amount of the gas phase desulfurization reaction products shall be used as the standard, and the mass percentage of the liquid phase components shall be 15-50%.

[0024] (3) The liquid phase component is pressurized and then subjected to a liquid phase dearomatization reaction in a hydrodearomatization reactor to obtain the liquid phase dearomatization reaction product;

[0025] The smoke point of the jet fuel is 16-22 mm.

[0026] In this invention, the hydrogen gas mentioned in step (1) can be any hydrogen-containing gas capable of providing hydrogen, including fresh hydrogen, recycled hydrogen, and hydrogen-rich gas. Those skilled in the art, after understanding the technical solution of this invention, can clearly understand the hydrogen-containing gas described in this invention.

[0027] In this invention, there is no particular limitation on the type of aviation kerosene feedstock, but preferably it is cut-weight aviation kerosene feedstock. In this invention, there is no particular limitation on the properties of the aviation kerosene. Preferably, in step (1), the initial boiling point of the aviation kerosene feedstock is 80-200℃, the final boiling point is 220-320℃, the S content is ≤5000μg / g, preferably ≤3000μg / g, the N content is ≤10μg / g, the smoke point is 20-22mm, and the aromatic hydrocarbon content is 15-30% v.

[0028] In this invention, there is no particular limitation on the type of hydrodesulfurization catalyst; any hydrodesulfurization catalyst capable of achieving the hydrodesulfurization reaction is applicable to this invention. Preferably, in step (1), the gas-phase desulfurization reaction is carried out under hydrodesulfurization catalyst conditions, wherein the hydrodesulfurization catalyst comprises a first support and a hydrodesulfurization active metal.

[0029] In this invention, there is no particular limitation on the type of the first carrier; carriers conventionally defined in the art are all applicable to this invention. Preferably, the first carrier is an inorganic refractory oxide, and more preferably, it is selected from at least one of alumina, amorphous aluminum silica, silicon dioxide, and titanium oxide.

[0030] In this invention, there is no particular limitation on the type of hydrogenation active metal; any active metal conventionally defined in the art is applicable to this invention. Preferably, the hydrogenation active metal is selected from at least one Group VIB metal component and / or at least one Group VIII metal component; more preferably, the Group VIB metal component is tungsten and / or molybdenum, and the Group VIII metal component is nickel and / or cobalt.

[0031] In this invention, preferably, based on the mass of the hydrodesulfurization catalyst, the content of the VIB metal component (calculated as oxide) is 10-20 wt%, and the content of the VIII metal component (calculated as oxide) is 1-9 wt%.

[0032] In this invention, there is no particular limitation on the source of the hydrodesulfurization catalyst. It can be prepared by conventional methods defined in the art or obtained commercially. For example, commercial hydrodesulfurization catalysts can be used, such as the FH-40 series catalysts developed by the Fushun Petrochemical Research Institute of Sinopec (FRIPP), such as FH-40A and FH-40B catalysts.

[0033] In this invention, by using a highly active desulfurization catalyst in the hydrodesulfurization reactor, the desulfurization reaction is controlled to follow a reaction path with lower hydrogen consumption, thereby reducing the chemical hydrogen consumption of the desulfurization reaction. At the same time, the hydrogen-to-oil volume ratio of the hydrodesulfurization reactor can also be reduced, thus reducing the severity of the reaction.

[0034] In this invention, preferably, in step (1), the conditions for the gas-phase desulfurization reaction include: a temperature of 220-400℃, a hydrogen-to-oil volume ratio of 5-400, a pressure of 0.1-2 MPa, and a volume hourly space velocity of 4-20 h⁻¹. -1 Further preferably, in step (1), the conditions for the gas-phase desulfurization reaction include: a temperature of 230-360℃, for example, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃, 300℃, 310℃, 320℃, 330℃, 330℃, 340℃, 350℃, 360℃, and any value between any two groups; a hydrogen-to-oil volume ratio of 20-300, for example, 20, 50, 100, 150, 200, 250, 300, and any value between any two groups; a pressure of 0.5-1.5MPa, for example, 0.5MPa, 1MPa, 1.5MPa, and any value between any two groups; and a volume hourly space velocity of 4-8 h⁻¹. -1 For example, it can be 4h -1 5h -1 6h -1 7h -1 8h -1 And the values ​​between any two groups. By controlling the conditions of the gas-phase desulfurization reaction, only the hydrogenation removal reaction of sulfides occurs in the gas-phase desulfurization reactor, thereby separating the desulfurization and dearomatization reactions, optimizing the reaction conditions respectively, and improving the reaction efficiency of each. It should be noted that in the gas-phase hydrogenation reaction in step (1), not only will sulfur in the jet fuel be removed, but also some small molecule nitrogen compounds (such as aliphatic amines) will be removed.

[0035] In this invention, preferably, in step (1), the sulfur content in the gas-phase desulfurization reaction product is 0.5-60 wt% of the sulfur content of the jet fuel raw material, more preferably 10-50 wt%, and even more preferably 15-25 wt%. By controlling the gas-phase desulfurization reaction, the sulfur content in the gas-phase desulfurization reaction product is kept within the above range, which effectively controls the depth of the desulfurization reaction and avoids the impact of deep desulfurization on the lubricity of the refined jet fuel product.

[0036] This invention utilizes a small amount of heat exchange at high temperature on the gas-phase desulfurization reaction products, retaining a large amount of reaction heat while ensuring the liquefaction of macromolecules, thus meeting the feed conditions for the hydrodearomatics reactor and saving energy. Preferably, the method further includes cooling the gas-phase desulfurization reaction products through heat exchange before the gas-liquid separation. In this invention, the heat exchange conditions are not particularly limited, as long as the liquefaction of large, heavy molecules in the gas-phase reaction products is ensured.

[0037] In this invention, the heat exchange can be carried out in a heat exchange unit (preferably a heat exchanger). This invention does not particularly limit the specific type of heat exchanger, for example, it can be a conventional commercial heat exchanger, such as a tubular heat exchanger.

[0038] In this invention, there are no particular limitations on the gas-liquid separation, which can be carried out in a gas-liquid separator. The gas-liquid separation is used to establish a gas-liquid balance in the effluent after heat exchange, allowing the gas phase component to flow upwards and the liquid phase component to flow downwards. This invention allows for a wide range of selection conditions for the gas-liquid separation. Preferably, based on the total amount of the gas-phase desulfurization reaction products, the mass percentage of the liquid phase component is 25-35%. This preferred embodiment is more conducive to accurately controlling the liquefaction ratio, allowing large molecules that require further reaction to enter the liquid phase component.

[0039] In this invention, there are no particular limitations on the specific operating conditions and methods of pressurization in step (3). In the preferred case, a booster pump is used as a booster unit to pressurize the liquid phase component so that the liquid phase component meets the conditions for liquid phase dearomatic reaction. In this invention, there are no particular limitations on the pressurization range.

[0040] In this invention, there is no particular limitation on the type of hydrodearomatization catalyst used in the liquid-phase dearomatization reaction. Preferably, in step (3), the liquid-phase dearomatization reaction is carried out in the presence of a hydrodearomatization catalyst, which is a noble metal catalyst and / or a non-noble metal catalyst.

[0041] In this invention, there is no particular limitation on the type of noble metal catalyst. Preferably, the noble metal catalyst comprises a second support and a noble metal element, wherein the noble metal element is Pd and / or Pt.

[0042] In this invention, the content of each component in the noble metal catalyst is not particularly limited, with the aim of achieving the hydrodearomatic reaction. Preferably, based on the noble metal catalyst, the content of Pd (based on elemental composition) is 0.1-0.2 wt%, and the content of Pt (based on elemental composition) is 0.01-0.1 wt%.

[0043] In this invention, there is no particular limitation on the type of noble metal catalyst. Preferably, the non-metallic catalyst comprises a third support and a non-noble metal element, wherein the non-noble metal element is selected from at least one group VIB metal component and / or at least one group VIII metal component; more preferably, the group VIB metal component is tungsten and / or molybdenum, and the group VIII metal component is nickel and / or cobalt.

[0044] In this invention, there is no particular limitation on the content of each component in the non-precious metal catalyst. Preferably, based on the mass of the non-precious metal catalyst, the content of the VIB metal component (calculated as oxide) is 10-20 wt%, and the content of the Group VIII metal component (calculated as oxide) is 1-9 wt%.

[0045] In this invention, there is no particular limitation on the types of the second and third supports. Preferably, the second and third supports are each independently an organic refractory oxide, and more preferably selected from at least one of alumina, amorphous aluminum silica, silicon dioxide, and titanium oxide.

[0046] In this invention, there are no particular limitations on the source of either the precious metal catalyst or the non-precious metal catalyst. Those skilled in the art can prepare them using conventionally defined methods or obtain them commercially. For example, the precious metal catalyst can be the FHDA-10 catalyst developed by the Sinopec Fushun Petrochemical Research Institute (FRIPP); the non-precious metal catalyst can be the FH-40 series catalysts developed by the Sinopec Fushun Petrochemical Research Institute (FRIPP), such as FH-40A and FH-40B catalysts.

[0047] In this invention, the selection range of conditions for the liquid-phase dearomatization reaction is relatively wide. In step (3), the conditions for the liquid-phase dearomatization reaction include: a pressure of 2-10 MPa, a temperature of 150-330 °C, and a volume hourly space velocity of 0.3-3 h⁻¹. -1 Further preferably, in step (3), the conditions for the liquid-phase dearomatic reaction include: a pressure of 3-6 MPa, a temperature of 225-330℃ (for example, 225℃, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃, 300℃, 310℃, 320℃, 330℃, and any value between two sets), and a volume hourly space velocity of 0.5-1.5 h⁻¹. -1 For example, it can be 0.5h -1 0.6h -1 0.7h -1 0.8h -1 0.9h -1 1h -1 1.1h -1 1.2h -11.3h -1 1.4h -1 1.5h -1 And the values ​​between any two groups.

[0048] In this invention, preferably, the pressure of the liquid-phase dearomatic reaction is at least 1 MPa higher than the pressure of the gas-phase desulfurization reaction, and more preferably 2-5 MPa higher. Under this preferred embodiment, the reaction is carried out at low pressure, which greatly reduces the severity of the reaction and saves energy.

[0049] In this invention, preferably, the temperature of the liquid-phase dearomatic reaction is at least 5°C lower than the temperature of the gas-phase desulfurization reaction, and more preferably 10-30°C lower. Under this preferred embodiment, macromolecules requiring further reaction can be liquefied while retaining the heat of reaction.

[0050] In this invention, there is no particular limitation on the specific types of hydrodesulfurization reactors and hydrodearomatics removal reactions. Preferably, the hydrodesulfurization reactor and the hydrodearomatics removal reactor are each independently a fixed-bed reactor.

[0051] In this invention, there are no particular limitations on the application of the gaseous components and liquid-phase dearomatization reaction products obtained from the gas-liquid separation. Adaptive processing can be performed according to the specific needs of the product. For example, the gaseous components and liquid-phase dearomatization reaction products can be processed separately or together, preferably together. Preferably, the method further includes optionally subjecting the gaseous components from step (2) to impurity removal treatment to obtain hydrogenated light components, which are then mixed with the liquid-phase dearomatization reaction products from step (3) and subjected to hydrogen sulfide removal treatment to obtain high smoke point jet fuel. This invention does not particularly limit the specific operation and conditions of the hydrogen sulfide removal treatment; it can be carried out using conventional techniques in the art, preferably stripping. In this invention, the stripping can be carried out in a stripping unit, such as a stripping tower.

[0052] In this invention, a high smoke point jet fuel product is obtained by the above method. Preferably, the high smoke point jet fuel product has a smoke point greater than 23 mm, more preferably greater than 25 mm, an sulfur content of less than 2000 μg / g, more preferably less than 1000 μg / g, and an aromatic hydrocarbon content of less than 23 v%, more preferably less than 20 v%.

[0053] According to a specific embodiment of the present invention, the aforementioned method of the present invention is carried out as follows: Figure 1The system shown in the diagram operates as follows: jet fuel and hydrogen 1 enter the hydrodesulfurization reactor 2 for gas-phase desulfurization reaction, yielding gas-phase desulfurization reaction product 3. The gas-phase desulfurization reaction product 3 enters the heat exchange unit 4, where it is cooled by heat exchange, and then enters the gas-liquid separation unit 5 for gas-liquid separation, yielding gas phase component 7 and liquid phase component 6. The liquid phase component 6 is pressurized by the pressurization unit 8 and then enters the hydrodearomatics reactor 9 for liquid-phase dearomatics reaction, yielding liquid-phase dearomatics reaction product 10. The gas phase component 7 and the liquid-phase dearomatics reaction product 10 are mixed and then subjected to stripping unit 11. After stripping, a high smoke point jet fuel product 12 is obtained.

[0054] The present invention will be further described below with reference to the embodiments, but it should be understood that the scope of protection of the present invention is not limited to the embodiments.

[0055] In this invention, unless otherwise explicitly stated, percentages and percentage contents are all expressed by mass.

[0056] The following is combined with Figure 1 The process flow of the present invention will be described in detail.

[0057] The jet fuel and hydrogen 1 enter the hydrodesulfurization reactor 2, where a gas-phase desulfurization reaction occurs, yielding a gas-phase desulfurization product 3. The gas-phase desulfurization product 3 enters the heat exchange unit 4 (heat exchanger), where it is cooled and then enters the gas-liquid separation unit 5 (gas-liquid separator) for gas-liquid separation, yielding a gas phase component 7 and a liquid phase component 6. The gas phase component 7 is discharged upwards from the gas-liquid separator, while the liquid phase component 6 is discharged downwards. After passing through the pressurization unit 8 (pressurization pump), the product enters the hydrodearomatics reactor 9, yielding a liquid phase dearomatics reaction product 10. The gas phase component 7 and the liquid phase dearomatics reaction product 10 are mixed and then enter the stripping unit 11 (stripping tower), ultimately yielding a high smoke point jet fuel product 12.

[0058] In the following examples and comparative examples, chemical hydrogen consumption refers to the percentage of hydrogen mass consumed per unit mass of raw material.

[0059]

[0060] The wear mark diameter of high smoke point aviation kerosene products was determined according to the SH / T 0687-2017 petrochemical standard.

[0061] Examples 1-3

[0062] Adopting such Figure 1The process flow diagram is shown below. Two 100mL fixed-bed hydrogenation reactors are connected in series: a hydrodesulfurization reactor and a hydrodearomatics removal reactor. A heat exchanger, a gas-liquid separator, and a booster pump are installed between the reactors. The hydrodesulfurization reactor is loaded with 30mL of Mo-Co type hydrogenation catalyst A, and the hydrodearomatics removal reactor is loaded with 70mL of Mo-Ni type hydrogenation catalyst B. A gas phase outlet is located above the gas-liquid separator, connected to the outlet of the hydrodearomatics removal reactor. The gas phase components and the liquid phase dearomatics removal products then enter a stripping tower to obtain high-smoke-point jet fuel.

[0063] Heavy jet fuel was used as the feedstock. Catalyst properties are shown in Table 1, feedstock oil properties are shown in Table 2, and reaction process conditions and results are shown in Table 3.

[0064] Example 4

[0065] The same process flow as in Examples 1-3 was used, except that the hydrogen-to-oil volume ratio at the inlet of the hydrodesulfurization reactor was increased. Catalyst properties are shown in Table 1, feedstock properties in Table 2, and reaction process conditions and results in Table 3.

[0066] Example 5

[0067] The same process flow as in Examples 1-3 was used, except that the gas-liquid separation conditions were changed. Catalyst properties are shown in Table 1, feedstock properties are shown in Table 2, and reaction process conditions and results are shown in Table 3.

[0068] Example 6

[0069] The process flow is the same as in Examples 1-3, except that the hydrogen-to-oil volume ratio at the inlet of the hydrodesulfurization reactor is reduced, and the pressurization system (booster pump) of the hydrodearomatics removal reactor is replaced with a pressurization and hydrogen mixing system, relative to 1m 3 The required hydrogen replenishment for the liquid phase component is 20 Nm³. 3 Hydrodesulfurization reactor 1 was loaded with 30 mL of Mo-Co type hydrogenation catalyst A, and hydrodearomatics removal reactor 2 was loaded with 70 mL of Mo-Ni type hydrogenation catalyst B. The properties of the raw materials and catalysts were the same as in Examples 1-3, and the reaction process conditions and results are shown in Table 3.

[0070] Comparative Example 1

[0071] A conventional fixed-bed hydrogenation process for aviation kerosene was adopted, with one hydrogenation reactor. The reactor was loaded with 100 mL of Mo-Co type light distillate oil hydrogenation catalyst A. Following the reactor, conventional processes such as low-temperature fractionation and stripping were implemented to obtain the aviation kerosene product. Hydrogen gas, after being desulfurized, was pressurized and recycled using a circulating hydrogen compressor. The properties of the feedstock and catalyst were the same as in Examples 1-3, and the reaction process conditions and results are shown in Table 3.

[0072] Table 1

[0073]

[0074] Table 2

[0075]

[0076] Table 3

[0077]

[0078] As shown in Table 3, in Example 4, the hydrogen-to-oil volume ratio at the inlet of the hydrodesulfurization reactor was too high, leading to difficulties in liquefaction during gas-liquid separation. Some aromatics entered the gas phase without undergoing hydrogenation, resulting in a low product smoke point. In Example 5, the gas-liquid separation process had significant heat exchange and a high liquefaction rate, but reheating was required during the liquid phase reaction to meet reaction conditions, resulting in high energy consumption. In Example 6, the hydrogen-to-oil volume ratio was reduced due to the lower hydrogen consumption of the hydrodesulfurization reactor. However, the reduced hydrogen partial pressure made feedstock gasification more difficult, requiring higher reaction temperatures and causing excessive sulfide removal, leading to increased energy and hydrogen consumption. Furthermore, a hydrogen mixer was needed to provide sufficient hydrogen for the liquid-phase hydrodeaeration reaction, increasing investment costs.

[0079] Comparative Example 1 uses conventional fixed-bed hydrogenation technology and a traditional catalyst loading system. The reactor pressure is high, leading to simultaneous and mutually influential desulfurization and dearomatization. Reaction conditions cannot be optimized for any single reaction. Sulfide removal under high pressure results in significant depth removal, affecting product lubricity and increasing hydrogen consumption. Hydrogen recycling also leads to high energy consumption. In contrast, the reaction system of this invention, with a significantly reduced reactor pressure for hydrodesulfurization, separates desulfurization and dearomatization into two separate reaction systems, allowing for targeted optimization of reaction conditions. This results in better retention of jet fuel sulfides, improved lubricity, and better dearomatization. Sulfides are removed via hydrogenolysis, reducing hydrogen consumption. Furthermore, hydrogen does not need to be recycled, further reducing energy consumption.

[0080] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for producing high smoke point aviation kerosene, characterized in that, The method includes the following steps: (1) In the presence of hydrogen, jet fuel is subjected to gas-phase desulfurization reaction in a hydrodesulfurization reactor to obtain gas-phase desulfurization reaction products; (2) The gas phase desulfurization reaction products are subjected to gas-liquid separation to obtain gas phase components and liquid phase components. The total amount of the gas phase desulfurization reaction products shall be used as the basis, and the mass percentage of the liquid phase components shall be 15-35%. (3) The liquid phase component is pressurized and then subjected to a liquid phase dearomatization reaction in a hydrodearomatization reactor to obtain the liquid phase dearomatization reaction product; The smoke point of the jet fuel is 16-22 mm. In step (1), the sulfur content in the gas-phase desulfurization reaction product is 10-50 wt% of the sulfur content of the jet fuel. The pressure of the liquid-phase dearomatic reaction is at least 1 MPa higher than the pressure of the gas-phase desulfurization reaction; In step (1), the conditions for the gas-phase desulfurization reaction include: a temperature of 220-330℃, a hydrogen-to-oil volume ratio of 20-100, a pressure of 0.1-1 MPa, and a volume hourly space velocity of 4-20 h⁻¹. -1 ; In step (3), the conditions for the liquid-phase dearomatic reaction include: a pressure of 2-6 MPa, a temperature of 150-330 °C, and a volume hourly space velocity of 0.3-3 h⁻¹. -1 ; The temperature of the liquid-phase dearomatic reaction is at least 5°C lower than the temperature of the gas-phase desulfurization reaction. The method also includes optionally removing impurities from the gas phase component described in step (2) to obtain a hydrogenated light component, which is then mixed with the liquid phase dearomatic reaction product described in step (3) and subjected to desulfurization treatment to obtain a high smoke point jet fuel product.

2. The method according to claim 1, wherein, In step (1), the initial boiling point of the jet fuel is 80-200℃, the final boiling point is 220-320℃, the S content is ≤5000μg / g, the N content is ≤10μg / g, the smoke point is 20-22mm, and the aromatic content is 15-30v.

3. The method according to claim 2, wherein, In step (1), the sulfur content of the jet fuel is ≤3000μg / g.

4. The method according to any one of claims 1-3, wherein, In step (1), the gas-phase desulfurization reaction is carried out under hydrodesulfurization catalyst conditions, wherein the hydrodesulfurization catalyst includes a first support and a hydroactive metal.

5. The method according to claim 4, wherein, The first carrier is an inorganic refractory oxide.

6. The method according to claim 5, wherein, The first carrier is selected from at least one of alumina, amorphous aluminum silica, silicon dioxide, and titanium dioxide.

7. The method according to claim 4, wherein, The hydrogenated active metal is selected from at least one group VIB metal component and / or at least one group VIII metal component.

8. The method according to claim 7, wherein, The Group VIB metal component is tungsten and / or molybdenum, and the Group VIII metal component is nickel and / or cobalt.

9. The method according to claim 7, wherein, Based on the mass of the hydrodesulfurization catalyst, the content of the VIB metal component (calculated as oxide) is 10-20 wt%, and the content of the VIII metal component (calculated as oxide) is 1-9 wt%.

10. The method according to any one of claims 1-3, wherein in step (1), the conditions for the gas-phase desulfurization reaction include: The temperature is 230-330℃, the hydrogen-to-oil volume ratio is 30-100, the pressure is 0.5-1MPa, and the volume hourly space velocity is 4-8h. -1 .

11. The method according to any one of claims 1-3, wherein, In step (1), the sulfur content in the gas phase desulfurization reaction product is 15-25 wt% of the sulfur content of the jet fuel.

12. The method according to any one of claims 1-3, wherein, The method also includes cooling the gas-phase desulfurization reaction products by heat exchange before performing the gas-liquid separation.

13. The method according to any one of claims 1-3, wherein, Based on the total amount of the gas-phase desulfurization reaction products, the mass percentage of the liquid phase component is 25-35%.

14. The method according to any one of claims 1-3, wherein, In step (3), the liquid-phase dearomatization reaction is carried out in the presence of a hydrodearomatization catalyst, which is a noble metal catalyst and / or a non-noble metal catalyst.

15. The method according to claim 14, wherein, The noble metal catalyst comprises a second support and a noble metal element, wherein the noble metal element is Pd and / or Pt.

16. The method according to claim 15, wherein, Based on precious metal catalysts, the Pd content is 0.1-0.2 wt% and the Pt content is 0.01-0.1 wt%.

17. The method according to claim 14, wherein, The non-precious metal catalyst includes a third support and a non-precious metal element, wherein the non-precious metal element is selected from at least one of the Group VIB metal components and / or at least one of the Group VIII metal components.

18. The method according to claim 17, wherein, The Group VIB metal component is tungsten and / or molybdenum, and the Group VIII metal component is nickel and / or cobalt.

19. The method according to claim 18, wherein, Based on the mass of the non-precious metal catalyst, the content of the VIB metal component (calculated as oxide) is 10-20 wt%, and the content of the non-precious metal element in the VIII group metal component (calculated as oxide) is 1-9 wt%.

20. The method of claim 15, wherein, The second carrier is an inorganic refractory oxide.

21. The method according to claim 17, wherein, The third carrier is an inorganic refractory oxide.

22. The method according to claim 20, wherein, The second carrier is selected from at least one of alumina, amorphous aluminum silica, silicon dioxide, and titanium oxide.

23. The method according to claim 21, wherein, The third carrier is selected from at least one of alumina, amorphous aluminum silica, silicon dioxide, and titanium dioxide.

24. The method according to any one of claims 1-3, wherein, In step (3), the conditions for the liquid-phase dearomatic reaction include: a pressure of 3-6 MPa, a temperature of 225-330 °C, and a volume hourly space velocity of 0.5-1.5 h⁻¹. -1 .

25. The method according to any one of claims 1-3, wherein, The pressure of the liquid-phase dearomatic reaction is 2-5 MPa higher than that of the gas-phase desulfurization reaction.

26. The method according to any one of claims 1-3, wherein, The temperature of the liquid-phase dearomatic reaction is 10-30°C lower than the temperature of the gas-phase desulfurization reaction.

27. The method according to any one of claims 1-3, wherein, The hydrodesulfurization reactor and the hydrodearomatics removal reactor are each an independent fixed-bed reactor.

28. The method according to any one of claims 1-3, wherein, The high smoke point aviation kerosene product has a smoke point greater than 23 mm, an S content less than 2000 μg / g, and an aromatic hydrocarbon content less than 23 v.

29. The method according to claim 28, wherein, The high smoke point aviation kerosene product has a smoke point greater than 25 mm, an S content of less than 1000 μg / g, and an aromatic hydrocarbon content of less than 20 v.

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