Method for producing aviation kerosene by hydrogenation of Fischer-Tropsch synthetic oil
By designing a multi-bed hydrocracking reactor, the problems of low yield and unstable quality in the production of jet fuel from Fischer-Tropsch synthetic oil were solved, resulting in improved jet fuel yield and product quality, and thus good economic benefits.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA ENERGY INVESTMENT CORP LTD
- Filing Date
- 2024-11-13
- Publication Date
- 2026-05-15
AI Technical Summary
In the existing Fischer-Tropsch synthesis process for producing jet fuel, the jet fuel fraction yield is low and the quality is unstable, with problems of over-cracking and high-temperature damage.
The multi-bed hydrocracking reactor design allows for the hydrorefining of Fischer-Tropsch synthetic oil into different components, which are then subjected to hydrocracking reactions in multiple beds. This avoids over-cracking of light fractions, improves jet fuel yield, and enhances product quality.
It significantly improved the jet fuel yield, improved product quality, reduced energy consumption, and increased throughput and economic efficiency.
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Figure CN122037985A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a method for producing aviation kerosene from Fischer-Tropsch synthesis oil by hydrogenation. BACKGROUND
[0002] Aviation kerosene is used as fuel for high-speed aviation turbine engines, and its demand is growing globally year by year. However, the existing production process is difficult to achieve high-efficiency and high-quality aviation kerosene output, which limits the improvement of supply and demand balance and economic benefits. Fischer-Tropsch synthesis technology is a technology path that converts coal or natural gas into liquid fuel through synthesis gas (H2+CO), and its products include Fischer-Tropsch light oil, heavy oil, and Fischer-Tropsch wax, etc. These products can be processed through hydrogenation refining, hydrocracking, isomerization, and fractionation processes to obtain different fuel fractions, including blending components for aviation kerosene. However, the traditional process of producing aviation kerosene from Fischer-Tropsch synthesis oil generally has low aviation kerosene fraction yield and unstable aviation kerosene quality.
[0003] The current process for producing aviation kerosene from Fischer-Tropsch synthesis oil usually adopts a fixed-bed hydrogenation refining and hydrocracking mode. Fischer-Tropsch synthesis oil is mixed with hydrogen and then enters a hydrogenation refining reactor. The generated olefins are saturated and deoxygenated by hydrogenation and then enter a fractionation system. Naphtha, diesel, and heavy oil fractions are separated in the fractionation column, and the heavy oil is continuously sent to a hydrocracking reactor for further cracking to generate more light fractions. However, due to the non-uniformity of the cracking reaction and the phenomenon of excessive cracking, the aviation kerosene fraction is often further cracked into low-value products, resulting in low aviation kerosene yield, and the high temperature generated during the cracking process easily damages the quality of the aviation kerosene. SUMMARY
[0004] The purpose of the present disclosure is to provide a method for producing aviation kerosene from Fischer-Tropsch synthesis oil by hydrogenation to improve the yield of aviation kerosene.
[0005] To achieve the above-mentioned purpose, the present disclosure provides a method for producing aviation kerosene from Fischer-Tropsch synthesis oil by hydrogenation, which comprises: hydrogenation refining the Fischer-Tropsch synthesis oil to obtain a Fischer-Tropsch synthesis oil hydrogenation refining product; first fractionating the Fischer-Tropsch synthesis oil hydrogenation refining product to obtain a first aviation kerosene fraction and a heavy component; introducing the heavy component and the first aviation kerosene fraction into a hydrocracking reactor for hydrocracking reaction to obtain a hydrocracking product; wherein the hydrocracking reactor has a top bed layer, a middle bed layer, and a lower bed layer arranged in sequence along the flow direction of the reaction material, the heavy component is introduced into the top bed layer, and the first aviation kerosene fraction is introduced into the lower bed layer; second fractionating the hydrocracking product to obtain a second aviation kerosene fraction, a middle distillate oil, and a tail oil; The tail oil and the middle distillate oil are recycled to the hydrocracking reactor; wherein the tail oil is introduced into the top bed and the middle distillate oil is introduced into the intermediate bed.
[0006] Optionally, the Fischer-Tropsch synthetic oil is a distillate oil with an initial boiling point of 50-150°C and a final boiling point of 700-800°C derived from a low-temperature iron-based Fischer-Tropsch synthesis process and / or a cobalt-based Fischer-Tropsch synthesis process.
[0007] Optionally, the Fischer-Tropsch synthetic oil has a sulfur content of less than 1 ppm, a nitrogen content of less than 1 ppm, and an oxygen content of less than 1 wt%.
[0008] Optionally, the hydrorefining reaction is carried out in a hydrorefining reactor, which is filled with a first hydrogenation catalyst; Based on the total weight of the first hydrogenation catalyst, the first hydrogenation catalyst comprises 80-90% by weight of a first support, 2-6% by weight of Ni, 7-12% by weight of Mo and / or W, and 1-3% by weight of Fe; the first support is alumina.
[0009] Optionally, the conditions for the hydrogenation purification reaction include: a temperature of 260~320℃ and a volume hourly space velocity of 1~3.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 300-1000, and the hydrogen partial pressure is 6-10 MPa.
[0010] Optionally, the conditions for the hydrocracking reaction include: a temperature of 330~380℃ and a volume hourly space velocity of 1~2.5h. -1 The hydrogen-to-oil volume ratio is 500-2000, and the hydrogen partial pressure is 6-15 MPa.
[0011] Optionally, in the hydrocracking reactor, the top bed and the middle bed are filled with a second hydrogenation catalyst, and the bottom bed is filled with a third hydrogenation catalyst.
[0012] Optionally, based on the total weight of the second hydrogenation catalyst, the second hydrogenation catalyst comprises 70-90% by weight of a second support, 2-12% by weight of Ni, and 8-28% by weight of Mo and / or W; the second support is amorphous silica and alumina. Based on the total weight of the third hydrogenation catalyst, the third hydrogenation catalyst comprises 50-70% by weight of a third support, 3-15% by weight of Ni, and 20-40% by weight of Mo and / or W; the third support is amorphous silicon-aluminum and alumina.
[0013] Optionally, in the hydrocracking reactor, the number of the top bed, the intermediate bed, and the bottom bed are one or more. The ratio of the number of top beds, middle beds and bottom beds is 1:(1~2):(1~2).
[0014] Optionally, the distillation range of the middle distillate oil is 260~440℃, preferably 270~420℃.
[0015] Through the above technical solution, this disclosure uses Fischer-Tropsch synthetic oil as feedstock for hydrorefining reaction, and fractionates the obtained hydrorefined products into different components, which are then sent to a hydrocracking reactor for deep cracking. Through the design of a multi-bed hydrocracking reactor, different components can undergo cracking reaction in different beds, effectively avoiding excessive cracking of light fractions, significantly improving the total yield of jet fuel, improving the quality of jet fuel products, and at the same time helping to reduce energy consumption, increase throughput and production economy.
[0016] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description
[0017] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of a specific embodiment of the method for producing jet fuel by hydrogenation of Fischer-Tropsch synthetic oil.
[0018] Explanation of reference numerals in the attached figures 1—Hydrorefining reactor, 2—First fractionation tower, 3—Hydrocracking reactor, 4—Second fractionation tower, 5—Fischer-Tropsch synthetic oil, 6—Hydrorefining product of Fischer-Tropsch synthetic oil, 7—First jet fuel fraction, 8—Heavy component, 9—Hydrocracking product, 10—Second jet fuel fraction, 11—Middle distillate oil, 12—Tail oil, 13—Naphtha. Detailed Implementation
[0019] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.
[0020] This disclosure provides a method for producing jet fuel by hydrogenating Fischer-Tropsch synthetic oil, with reference to... Figure 1 The method includes: Fischer-Tropsch synthetic oil 5 was subjected to a hydrorefining reaction to obtain Fischer-Tropsch synthetic oil hydrorefining product 6. The hydrorefined product 6 of the Fischer-Tropsch synthetic oil is subjected to a first fractionation to obtain a first jet fuel fraction 7 and a heavy component 8. The heavy component 8 and the first jet fuel fraction 7 are introduced into the hydrocracking reactor 3 for hydrocracking reaction to obtain hydrocracking product 9; wherein, the hydrocracking reactor 3 has a top bed, an intermediate bed and a bottom bed arranged sequentially along the flow direction of the reactants, the heavy component 8 is introduced into the top bed and the first jet fuel fraction 7 is introduced into the bottom bed; The hydrocracking product 9 is subjected to a second fractionation to obtain a second jet fuel fraction 10, a middle distillate oil 11, and a tail oil 12. The tail oil 12 and the middle distillate oil 11 are recycled to the hydrocracking reactor 3; wherein the tail oil 12 is introduced into the top bed and the middle distillate oil 11 is introduced into the middle bed.
[0021] According to this disclosure, the Fischer-Tropsch synthetic oil 5 refers to a liquid hydrocarbon mixture converted from syngas (mainly composed of carbon monoxide and hydrogen) through the Fischer-Tropsch synthesis process. Specifically, it may include Fischer-Tropsch light oil, Fischer-Tropsch medium oil, and Fischer-Tropsch heavy wax. In one embodiment, the Fischer-Tropsch synthetic oil is a distillate oil produced from a low-temperature iron-based Fischer-Tropsch synthesis process and / or a cobalt-based Fischer-Tropsch synthesis process, with an initial boiling point of 50-150°C and a final boiling point of 700-800°C (i.e., a boiling range of 50-800°C). The sulfur content of the Fischer-Tropsch synthetic oil may be less than 1 ppm, the nitrogen content may be less than 1 ppm, and the oxygen content may be less than 1 wt%. Among them, the low-temperature iron-based Fischer-Tropsch synthesis process refers to the Fischer-Tropsch synthesis process that uses iron-based catalysts, operates at temperatures typically between 200 and 300°C, and produces heavier hydrocarbon heavy oil products; the cobalt-based Fischer-Tropsch synthesis process refers to the Fischer-Tropsch synthesis process that uses cobalt-based catalysts, operates at temperatures typically between 220 and 250°C, and produces alkanes with medium carbon numbers, light oils, and heavy wax products.
[0022] The hydrorefining reaction can be carried out in a hydrorefining reactor 1, which is packed with a first hydrorefining catalyst to promote the olefin saturation and deoxygenation reaction in the Fischer-Tropsch synthesis oil. In one specific embodiment, the first hydrorefining catalyst may include a first support and a first metal component, wherein the first support may be alumina, and the first metal component includes one or more of Ni, Mo, W, and Fe. Preferably, based on the total weight of the first hydrorefining catalyst, the first hydrorefining catalyst may include 80-90% by weight of alumina, 2-6% by weight of Ni, 7-12% by weight of Mo and / or W, and 1-3% by weight of Fe.
[0023] The conditions for the hydrogenation purification reaction may include: a temperature of 260–320 °C and a volume hourly space velocity of 1–3.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 300-1000, and the hydrogen partial pressure is 6-10 MPa.
[0024] The first fractionation can be carried out in the first fractionation tower 2, and the conditions for the first fractionation may include: a temperature of 250~300℃ and a pressure of 0.1~0.2MPa. The first fractionation yields naphtha 13, a first jet fuel fraction 7, and a heavy component 8, wherein the boiling range of the first jet fuel fraction 7 is 130~290℃, the boiling range of the heavy component 8 is 290~800℃, and the boiling range of naphtha 13 is 50~130℃. By subjecting the Fischer-Tropsch synthesis oil hydrorefining product 6 to the first fractionation, the different components obtained from the separation can be selectively introduced into different beds of the hydrocracking reactor 3, avoiding over-cracking of the jet fuel fraction, improving jet fuel yield, and enhancing product quality.
[0025] According to this disclosure, the hydrocracking reaction is carried out in a hydrocracking reactor 3, which is provided with a top bed, an intermediate bed, and a bottom bed from top to bottom. Each bed is used for the hydrocracking treatment of different components. Specifically, the reaction conditions of the top bed are suitable for deep hydrocracking, which can effectively crack heavy components (including heavy component 8 from the first fractionation tower 2 and circulating tail oil 12 from the second fractionation tower 4), providing more suitable intermediate products for downstream reactions; the intermediate bed processes the material from the top bed and the middle distillate oil 11 from the second fractionation tower 4, further cracking the larger molecules therein to generate more intermediate hydrocarbons and light hydrocarbons; the bottom bed processes the material from the intermediate bed and the first jet fuel fraction 7 from the first fractionation tower 2, performing mild cracking and pour point depressing treatment to maintain the yield and quality of the jet fuel product.
[0026] The hydrocracking reactor 3 can be packed with one or more hydrocracking catalysts. By designing the type of catalyst, it is beneficial to improve the catalyst utilization rate and achieve the desired cracking effect. For example, in the hydrocracking reactor 3, the top bed and the middle bed can be packed with a second hydrocracking catalyst with high cracking activity and high temperature resistance, and the lower bed can be packed with a third hydrocracking catalyst with mild hydrocracking activity and pour point depressant effect.
[0027] In one specific embodiment, the second hydrogenation catalyst may include a second support and a second metal component, wherein the second support may be one or more of amorphous silica-alumina, molecular sieves and alumina, preferably amorphous silica-alumina and alumina; the second metal component includes at least one of Group VIB and / or Group VIII non-noble metals; more preferably, based on the total weight of the second hydrogenation catalyst, the second hydrogenation catalyst may include 70-90% by weight of the second support, 2-12% by weight of Ni, and 8-28% by weight of Mo and / or W.
[0028] In one specific embodiment, the third hydrogenation catalyst may include a third support and a third metal component, wherein the third support may be amorphous silica-alumina and alumina, and the third metal component includes one or more of Ni, Mo, and W. More preferably, based on the total weight of the third hydrogenation catalyst, the third hydrogenation catalyst may include 50-70% by weight of alumina, 3-15% by weight of Ni, and 20-40% by weight of Mo and / or W.
[0029] In the hydrocracking reactor 3, the number of the top bed, the middle bed, and the bottom bed can be one or more, which can be adjusted according to process needs to adapt to the cracking requirements of different types of Fischer-Tropsch synthetic oils and achieve optimized cracking effect. In a preferred embodiment, the ratio of the number of the top bed, the middle bed, and the bottom bed is 1:(1~2):(1~2).
[0030] The conditions for the hydrocracking reaction may include: a temperature of 330–380 °C and a volume hourly space velocity (VHSV) of 1–2.5 h⁻¹. -1 The hydrogen-to-oil volume ratio is 500-2000, and the hydrogen partial pressure is 6-15 MPa.
[0031] The second fractionation can be carried out in the second fractionation tower 4. The conditions for the second fractionation may include a temperature of 240~310℃ and a pressure of 0.1~0.2MPa. The second fractionation yields naphtha 13, second jet fuel fraction 10, middle distillate oil 11, and tail oil 12. The boiling range of the second jet fuel fraction 10 is 130~290℃; the boiling range of the middle distillate oil 11 is 260~440℃, preferably 270~420℃; the boiling range of the tail oil 12 is 400~800℃; and the boiling range of the naphtha 13 is 50~130℃. All the tail oil 12 and middle distillate oil 11 obtained from the second fractionation are recycled to the hydrocracking reactor 3, which helps to improve the jet fuel yield, improve product quality, and simultaneously reduce energy consumption and increase throughput.
[0032] According to this disclosure, the second aviation kerosene fraction 10 can be collected as aviation kerosene product. The method disclosed herein is beneficial for improving the overall aviation kerosene yield and the quality of aviation kerosene products, and can meet the growing demand for aviation kerosene, possessing good economic benefits and market application prospects. Specifically, the overall aviation kerosene yield can reach over 70%, the closed-cup flash point of the aviation kerosene can be no lower than 41℃, and the freezing point can be no higher than -48℃.
[0033] The embodiments provided below further illustrate the methods of this disclosure, but do not limit the scope of this disclosure.
[0034] Example 1 According to such Figure 1The process shown uses Fischer-Tropsch synthetic oil to produce jet fuel via hydrogenation. The Fischer-Tropsch synthetic oil used is derived from a low-temperature iron-based Fischer-Tropsch synthesis process, and its properties are shown in Table 1. The hydrocracking reactor 3 has a top bed (1), an intermediate bed (1), and a bottom bed (2). The catalyst composition packed in the top and intermediate beds includes 75 wt% amorphous silica and alumina, 5 wt% Ni, 10 wt% Mo, and 10 wt% W. The catalyst composition packed in the bottom bed includes 55 wt% amorphous silica and alumina, 10 wt% Ni, 15 wt% Mo, and 20 wt% W. The catalyst composition packed in the hydrorefining reactor 1 includes 85 wt% alumina, 3 wt% Ni, 10 wt% Mo, and 2 wt% Fe.
[0035] Fischer-Tropsch synthetic oil, along with hydrogen, enters hydrorefining reactor 1 for hydrorefining. The resulting Fischer-Tropsch synthetic oil hydrorefining product 6 enters the first fractionation tower 2 for fractionation at 270℃ and 0.1MPa, breaking it down into naphtha 13 (distillation range 50~130℃), first jet fuel fraction 7 (distillation range 130~290℃), and heavy component 8 (distillation range 290~800℃). Heavy component 8, along with hydrogen, enters the top bed of hydrocracking reactor 3, while the entire first jet fuel fraction 7 enters the lower bed for hydrocracking. The hydrocracking product 9 enters the second fractionation tower 4 for fractionation at a temperature of 285℃ and a pressure of 0.12MPa, and is cut into naphtha 13 (distillation range 50~130℃), second jet fuel fraction 10 (distillation range 130~290℃), middle distillate oil 11 (distillation range 290~400℃) and tail oil 12 (distillation range 400~800℃). The tail oil 12 is completely recycled to the top bed of the hydrocracking reactor 3, the middle distillate oil 11 is completely recycled to the middle bed of the hydrocracking reactor 3, and the second jet fuel fraction 10 is used as a product extraction device.
[0036] The operating conditions of hydrorefining reactor 1 and hydrocracking reactor 3 are shown in Table 2, and the yield and properties of the obtained jet fuel products are shown in Table 3. The jet fuel yield is calculated according to the following formula: Jet kerosene yield (%) = Second jet kerosene fraction 10 yield / (Second jet kerosene fraction 10 yield + Total naphtha yield) × 100% Example 2 The jet fuel was produced according to the method of Example 1, except that the middle distillate oil 11 had a distillation range of 260~440°C.
[0037] The yield and properties of the aviation kerosene product obtained in this embodiment are shown in Table 3.
[0038] Example 3 The method for producing jet fuel according to Example 1 differs in that the number of beds in the top bed of the hydrocracking reactor 3 is 2, the number of beds in the middle bed is 1, and the number of beds in the bottom bed is 1.
[0039] The yield and properties of the aviation kerosene product obtained in this embodiment are shown in Table 3.
[0040] Comparative Example 1 The method of producing jet fuel according to Example 1 differs in that the first jet fuel fraction 7 and heavy fraction 8 obtained from the first fractionation tower 2 are all introduced into the top bed of the hydrocracking reactor 3 for hydrocracking reaction, and the middle distillate oil 11 and tail oil 12 (distillation range 400~800℃) obtained from the second fractionation tower 4 are all recycled to the top bed of the hydrocracking reactor 3.
[0041] The yield and properties of the aviation kerosene products obtained in this comparative example are shown in Table 3.
[0042] Table 1
[0043] Table 2
[0044] Table 3
[0045] As shown in Table 3, the method disclosed herein has a significantly improved jet fuel yield and the jet fuel product quality is superior.
[0046] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.
[0047] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.
[0048] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.
Claims
1. A method for producing jet fuel by hydrogenating Fischer-Tropsch synthetic oil, characterized in that, The method includes: The Fischer-Tropsch synthetic oil was subjected to a hydrorefining reaction to obtain the hydrorefined product of the Fischer-Tropsch synthetic oil. The hydrorefined product of the Fischer-Tropsch synthetic oil is subjected to a first fractionation to obtain a first jet fuel fraction and a heavy component. The heavy components and the first jet fuel fraction are introduced into a hydrocracking reactor for hydrocracking reaction to obtain hydrocracking products; wherein, the hydrocracking reactor has a top bed, an intermediate bed and a bottom bed arranged sequentially along the flow direction of the reactants, the heavy components are introduced into the top bed and the first jet fuel fraction is introduced into the bottom bed; The hydrocracking products are subjected to a second fractionation to obtain a second jet fuel fraction, middle distillate oil and tail oil. The tail oil and the middle distillate oil are recycled to the hydrocracking reactor; wherein the tail oil is introduced into the top bed and the middle distillate oil is introduced into the intermediate bed.
2. The method according to claim 1, wherein, The Fischer-Tropsch synthetic oil is a distillate oil with an initial boiling point of 50-150°C and a final boiling point of 700-800°C, derived from a low-temperature iron-based Fischer-Tropsch synthesis process and / or a cobalt-based Fischer-Tropsch synthesis process.
3. The method according to claim 2, wherein, The Fischer-Tropsch synthetic oil has a sulfur content of less than 1 ppm, a nitrogen content of less than 1 ppm, and an oxygen content of less than 1 wt%.
4. The method according to claim 1, wherein, The hydrorefining reaction is carried out in a hydrorefining reactor, which is filled with a first hydrogenation catalyst. Based on the total weight of the first hydrogenation catalyst, the first hydrogenation catalyst comprises 80-90% by weight of a first support, 2-6% by weight of Ni, 7-12% by weight of Mo and / or W, and 1-3% by weight of Fe; the first support is alumina.
5. The method according to claim 1, wherein, The conditions for the hydrogenation purification reaction include: a temperature of 260–320 °C and a volume hourly space velocity (VHSV) of 1–3.0 h⁻¹. -1 The hydrogen-to-oil volume ratio is 300-1000, and the hydrogen partial pressure is 6-10 MPa.
6. The method according to claim 1, wherein, The conditions for the hydrocracking reaction include: a temperature of 330–380 °C and a volume hourly space velocity (VHSV) of 1–2.5 h⁻¹. -1 The hydrogen-to-oil volume ratio is 500-2000, and the hydrogen partial pressure is 6-15 MPa.
7. The method according to claim 1, wherein, In the hydrocracking reactor, the top bed and the middle bed are filled with a second hydrogenation catalyst, and the bottom bed is filled with a third hydrogenation catalyst.
8. The method according to claim 7, wherein, Based on the total weight of the second hydrogenation catalyst, the second hydrogenation catalyst comprises 70-90% by weight of a second support, 2-12% by weight of Ni, and 8-28% by weight of Mo and / or W; the second support is amorphous silica and alumina. Based on the total weight of the third hydrogenation catalyst, the third hydrogenation catalyst comprises 50-70% by weight of a third support, 3-15% by weight of Ni, and 20-40% by weight of Mo and / or W; the third support is amorphous silicon-aluminum and alumina.
9. The method according to claim 1, wherein, In the hydrocracking reactor, the number of the top bed, the intermediate bed, and the bottom bed are one or more; The ratio of the number of top beds, middle beds and bottom beds is 1:(1~2):(1~2).
10. The method according to claim 1, wherein, The distillation range of the middle distillate oil is 260~440℃, preferably 270~420℃.