Coal-based Fischer-Tropsch synthetic fuel oil as well as preparation method and application thereof

Abstract

The invention provides coal-based Fischer-Tropsch synthetic fuel oil as well as a preparation method and application thereof. The preparation method of the coal-based Fischer-Tropsch synthesis fuel oil comprises the following steps: carrying out first fractionation, hydrofining and second fractionation on Fischer-Tropsch synthesis crude oil to obtain a hydrofined diesel oil fraction and hydrofined tail oil; then performing hydrocracking and third fractionation on the hydrofined tail oil to obtain a hydrocracking diesel oil fraction; in addition, each hydrocracking diesel oil fraction is rectified to obtain a side line component and coal-based Fischer-Tropsch synthesis fuel oil; and finally, fractionating the side components to obtain the coal-based Fischer-Tropsch synthetic fuel oil. According to the invention, the indirect coal liquefaction Fischer-Tropsch synthesis crude oil is subjected to fractionation, hydrofining, hydrocracking and fractionation to prepare three kinds of fuel oil. Compared with petroleum-based fuel oil, the coal-based Fischer-Tropsch synthesis fuel oil disclosed by the invention is low in sulfur and nitrogen content, low in acid value, low in ash content, rich in raw material resource and wide in source, and can be applied to household or industrial small combustors.

Description

Technical Field

[0001] The present invention relates to the technical field of coal chemical industry, and in particular to a coal-based Fischer-Tropsch synthetic fuel oil, a preparation method thereof and an application thereof. Background Art

[0002] Fuel oil, as one of the finished oil products, is a heavier residual product separated from crude oil after gasoline, coal and diesel in the oil processing process. Fuel oil is mainly made from cracked residual oil and straight run residual oil of petroleum. It is characterized by high viscosity and contains a lot of non-hydrocarbon compounds, colloids and asphaltene. It is widely used in household, ship engines or industrial burners. Compared with gasoline, diesel and jet fuel used in internal combustion engines, fuel oil generally belongs to fuel oil or residual fuel oil with heavier fraction composition.

[0003] Fuel oil should be free of inorganic acids, excessive solids and foreign fibrous substances. In addition, fuel oil should have good atomization performance and low corrosiveness, and contain less colloid and asphalt, so that the fuel oil can be fully burned and less coking, thereby extending the service life of the furnace. The performance indicators of fuel oil mainly include viscosity, low temperature performance, sulfur content and stability. Sulfur compounds in fuel oil will generate SO after combustion. 2 and SO 3 , SO 2 and SO 3 Not only does it pollute the environment and harm human health, but the sulfurous acid and sulfuric acid formed when it comes into contact with water will seriously corrode metal equipment. Therefore, the lower the sulfur content in fuel oil, the better.

[0004] Existing fuel oil is basically derived from petroleum-based products, mainly made from cracked petroleum and straight-run residual oil. Petroleum-based fuel oil has a high sulfur content and is not clean. In addition, since my country is a country with a large number of coal resources and a shortage of petroleum resources, as the demand for fuel oil in my country continues to grow, new fuel oil substitutes are gaining more and more attention.

[0005] Invention patent CN 110229686 A discloses a low-sulfur marine distillate fuel oil and its preparation method. The deep-processed oil product after direct liquefaction of coal powder is fractionated and cut to 180-380℃ distillation range A-1 base oil or 160-340℃ distillation range A-2 base oil, that is, low-sulfur marine distillate fuel oil is obtained. This invention only needs to add a small amount of viscosity enhancer to the directly blended DMA oil to obtain a marine distillate fuel oil of model DMZ. This marine distillate fuel oil has the advantages of very low sulfur and nitrogen content, low acid value, low ash content, and good low-temperature fluidity. Invention patent CN 114752411 A discloses a method for preparing multi-purpose fuel oil. Coal direct liquefaction oil is cut to obtain a light component with a boiling point ≤220℃ and a heavy component with a boiling point >220℃. The liquid oil obtained by two-step hydrogenation of the heavy component is mixed with the light component and fractionated to obtain a multi-purpose fuel oil with a boiling point ≥160℃. It can be used for jet aircraft, ground vehicles, and watercraft, and is suitable for industrial promotion. However, the above schemes all use coal direct liquefaction oil as raw material to prepare fuel oil, and there are still defects such as high sulfur content and aromatic content in the oil products. Summary of the invention

[0006] The main purpose of the present invention is to provide a coal-based Fischer-Tropsch synthetic fuel oil, a preparation method and application thereof, so as to solve the problems of high sulfur content, uncleanness and shortage of raw material resources of fuel oil in the prior art.

[0007] In order to achieve the above-mentioned object, according to one aspect of the present invention, a method for preparing coal-based Fischer-Tropsch synthetic fuel oil is provided. The preparation method comprises the following steps: step S1, using coal as raw material, preparing Fischer-Tropsch synthetic crude oil through coal indirect liquefaction Fischer-Tropsch synthesis reaction, subjecting the Fischer-Tropsch synthetic crude oil to a first fractionation to obtain Fischer-Tropsch stable heavy oil; step S2, subjecting the Fischer-Tropsch stable heavy oil to a hydrorefining product; subjecting the hydrorefining product to a second fractionation to obtain a hydrorefining diesel fraction, a hydrorefining tail oil and a hydrorefining gasoline fraction with a boiling point of less than 195°C; step S3, subjecting the hydrorefining product to a second fractionation to obtain a hydrorefining diesel fraction, a hydrorefining tail oil and a hydrorefining gasoline fraction with a boiling point of less than 195°C; step S4, subjecting the hydrorefining product to a second fractionation to obtain a hydrorefining diesel fraction, a hydrorefining tail oil and a hydrorefining gasoline fraction with a boiling point of less than 195°C; step S5, subjecting the hydrorefining product to a second fractionation to obtain a hydrorefining diesel fraction, a hydrorefining tail oil and a hydrorefining gasoline fraction with a boiling point of less than 195°C; step S6, subjecting the hydrorefining product to a second fractionation to obtain a hydrorefining diesel fraction, a hydrorefining tail oil and a hydrorefining gasoline fraction with a boiling point of less than 195°C; step S7, subjecting the hydrorefining product to a second fractionation to obtain a hydrorefining diesel fraction, a hydrorefining tail oil and a hydrorefining gasoline fraction with a boiling point of less than 195°C; step S8, subjecting the hydrorefining product to a second fractionation to obtain a hydrorefining diesel fraction, a hydrorefin The hydrorefined tail oil is subjected to hydrocracking to obtain a hydrocracking product; the hydrocracking product is subjected to a third fractionation to obtain a hydrocracking tail oil, a hydrocracking gasoline fraction and a hydrocracking diesel fraction; wherein the initial boiling point of the hydrocracking diesel fraction is 160-180°C, and the final boiling point is 280-350°C; step S4, the hydrorefined diesel fraction and the hydrocracking diesel fraction are sent to a distillation tower for distillation to obtain a light diesel component at the top of the distillation tower, a light diesel component at the side of the distillation tower, and a light diesel component at the top of the distillation tower. The first fuel oil component of the distillation tower side line, the second fuel oil component of the distillation tower side line and the first coal-based Fischer-Tropsch synthetic fuel oil; wherein the initial distillation point of the first fuel oil component of the distillation tower side line is 120-160°C, and the final distillation point is 230-250°C, the initial distillation point of the second fuel oil component of the distillation tower side line is 130-160°C, and the final distillation point is 250-275°C, and the initial distillation point of the first coal-based Fischer-Tropsch synthetic fuel oil is 220-240°C, and the final distillation point is 300-320°C ; Step S5, subjecting the first fuel oil component of the side line of the distillation tower to the fourth fractionation to obtain a second coal-based Fischer-Tropsch synthetic fuel oil; subjecting the second fuel oil component of the side line of the distillation tower to the fifth fractionation to obtain a third coal-based Fischer-Tropsch synthetic fuel oil; wherein, the second coal-based Fischer-Tropsch synthetic fuel oil has an initial distillation point of 170-195°C, and a final distillation point of 230-250°C, and the third coal-based Fischer-Tropsch synthetic fuel oil has an initial distillation point of 225-245°C, and a final distillation point of 250-275°C.

[0008] Furthermore, in step S1, the preparation step of Fischer-Tropsch synthesis crude oil is: coal is gasified to obtain synthesis gas, and the synthesis gas is subjected to Fischer-Tropsch synthesis reaction to prepare Fischer-Tropsch synthesis crude oil; wherein the synthesis gas includes H 2 , CO, the molar ratio of the two is (1.3-1.9):1; preferably, the reaction temperature of coal gasification is 1200-1750°C; and / or the reaction pressure is 3-5MPa; and / or the coal includes one or more of lignite, bituminous coal and anthracite; and / or the catalyst for the Fischer-Tropsch synthesis reaction includes one or more of Fe-based catalysts, Co-based catalysts, Ni-based catalysts and Ru-based catalysts.

[0009] Furthermore, in step S1, the first fractionation is performed in a first distillation tower, the bottom temperature of the first distillation tower is 300-350°C, and the top pressure is 0.1-0.2 MPa.

[0010] Furthermore, in step S2, the reaction temperature of the hydrofining is 250-350°C, preferably 260-300°C; and / or the reaction pressure is 2-8 MPa, preferably 3-6 MPa; and / or the volume space velocity is 0.5-3 h -1 , preferably 0.5 to 2 hours -1 ; and / or the hydrogen-to-oil ratio is 200-700, preferably 250-400; and / or the hydrotreating catalyst comprises a first carrier and a first active metal component supported on the first carrier; preferably, the mass ratio of the first active metal component to the first carrier is (3-8):1000; and / or the first carrier comprises one or more of silicon oxide, aluminum oxide and titanium oxide; and / or the first active metal component comprises one or more of Co, Pt, Pd, Ni, W and Mo; and / or the second fractionation is carried out in a second fractionation tower, and the bottom temperature of the second fractionation tower is 280-350°C, preferably 310-340°C; and / or the top temperature is 100-145°C, preferably 100-130°C; and / or the bottom pressure is 0.1-1.1MPa, preferably 0.2-0.6MPa.

[0011] Furthermore, in step S3, the reaction temperature of the hydrocracking is 300-380°C, preferably 300-350°C; and / or the reaction pressure is 2-8 MPa, preferably 3-7 MPa; and / or the volume space velocity is 0.5-3.5 h -1 , preferably 0.5 to 1.5h -1 ; and / or the hydrogen-to-oil ratio is 200-800, preferably 200-500; and / or the hydrocracking catalyst comprises a second carrier and a second active metal component supported on the second carrier; preferably, the mass ratio of the second active metal component to the second carrier is (2-7):1000; and / or the second carrier comprises one or more of silicon oxide, aluminum oxide and titanium oxide; and / or the second active metal component comprises one or more of Co, Pt, Pd, Ni, W and Mo; and / or the third fractionation is carried out in the third fractionation tower, and the bottom temperature of the third fractionation tower is 290-360°C, preferably 300-335°C; and / or the top temperature is 100-160°C, preferably 100-140°C; and / or the bottom pressure is 0.1-1.2MPa, preferably 0.1-0.6MPa.

[0012] Further, in step S4, the hydrorefined diesel fraction and the hydrocracked diesel fraction are first mixed and then distilled in the same distillation tower; preferably, the mass ratio of the hydrorefined diesel fraction to the hydrocracked diesel fraction is (1-50):1; and / or the hydrorefined diesel fraction and the hydrocracked diesel fraction are distilled in the same distillation tower in a switching feed mode; preferably, the mass ratio of the hydrorefined diesel fraction to the hydrocracked diesel fraction is (1-50):1; and / or the hydrorefined diesel fraction and the hydrocracked diesel fraction are fed into different distillation towers in an independent feeding mode for distillation.

[0013] Furthermore, in step S4, the top temperature of the distillation tower is 70-110° C.; and / or the bottom temperature is 200-280° C.; and / or the top pressure is 15-25 kPa.

[0014] Further, in step S5, the fourth distillation is carried out in the first side-line tower, the bottom temperature of the first side-line tower is 140-190°C; and / or the top temperature is 50-90°C; and / or the bottom pressure is 0.1-1MPa; and / or the fifth distillation is carried out in the second side-line tower, the bottom temperature of the second side-line tower is 180-220°C; and / or the top temperature is 80-100°C; and / or the bottom pressure is 0.1-1MPa.

[0015] According to another aspect of the present invention, there is provided a coal-based Fischer-Tropsch synthetic fuel oil obtained by the above-mentioned preparation method.

[0016] According to another aspect of the present invention, there is provided a use of the above-mentioned coal-based Fischer-Tropsch synthetic fuel oil in a domestic burner and / or an industrial burner.

[0017] By applying the technical solution of the present invention, three types of fuel oils are prepared by fractionating, hydrofining, hydrocracking and fractionating the crude oil of coal indirect liquefaction Fischer-Tropsch synthesis. Compared with petroleum-based fuel oil, coal-based Fischer-Tropsch synthesis fuel oil has low sulfur and nitrogen content, low acid value and low ash content, and is a clean and environmentally friendly substitute for furnace fuel oil. Moreover, the raw material resources are abundant and the sources are wide, and it can be applied to small household or industrial burners. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0019] Figure 1 A schematic diagram of the process flow for preparing coal-based Fischer-Tropsch synthetic fuel oil according to Example 1 of the present invention is shown.

[0020] The above drawings include the following reference numerals:

[0021] 1. Fischer-Tropsch reactor of coal indirect liquefaction process; 2. first fractionation tower; 3. hydrofining reactor; 4. second fractionation tower; 5. hydrocracking reactor; 6. third fractionation tower; 7. storage tank; 8. feed pump; 9. distillation tower; 10. first side-line tower; 11. second side-line tower;

[0022] A, raw material; B, Fischer-Tropsch synthesis crude oil; C, first oil fraction; D, Fischer-Tropsch stabilized heavy oil; E, hydrorefining product; F, hydrorefining gasoline fraction; G, hydrorefining diesel fraction; H, hydrorefining tail oil; I, hydrocracking product; J, hydrocracking gasoline fraction; K, hydrocracking diesel fraction; L, hydrocracking tail oil; M, mixed fraction; N, second oil fraction; O, first fuel oil component of distillation tower side line; P, second fuel oil component of distillation tower side line; Q, first coal-based Fischer-Tropsch synthesis fuel oil; R, third oil fraction; S, second coal-based Fischer-Tropsch synthesis fuel oil; T, fourth oil fraction; U, third coal-based Fischer-Tropsch synthesis fuel oil. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] As described in the background technology of the present invention, the existing technology has the problems of high sulfur content, uncleanness and shortage of raw material resources in fuel oil. In order to solve the above problems, in a typical embodiment of the present invention, a method for preparing coal-based Fischer-Tropsch synthetic fuel oil is provided. The preparation method comprises the following steps: Step S1, using coal as raw material, preparing Fischer-Tropsch synthetic crude oil through coal indirect liquefaction Fischer-Tropsch synthesis reaction, and subjecting the Fischer-Tropsch synthetic crude oil to a first fractionation to obtain Fischer-Tropsch stable heavy oil; Step S2, hydrofining the Fischer-Tropsch stable heavy oil to obtain a hydrofining product; subjecting the hydrofining product to a second fractionation to obtain a hydrofining diesel fraction, a hydrofining tail oil and a hydrofining gasoline fraction with a boiling point of <195°C; Step S3, The hydrorefined tail oil is hydrocracking to obtain a hydrocracking product; the hydrocracking product is subjected to a third fractionation to obtain a hydrocracking tail oil, a hydrocracking gasoline fraction and a hydrocracking diesel fraction; wherein the initial distillation point of the hydrocracking diesel fraction is 160-180°C, and the final distillation point is 280-350°C; step S4, the hydrorefined diesel fraction and the hydrocracking diesel fraction are sent to a distillation tower for distillation to obtain a light diesel component at the top of the distillation tower, a distillation tower, and a distillation tower. The first fuel oil component of the side line, the second fuel oil component of the distillation tower side line and the first coal-based Fischer-Tropsch synthetic fuel oil; wherein the initial distillation point of the first fuel oil component of the distillation tower side line is 120-160°C, and the final distillation point is 230-250°C, the initial distillation point of the second fuel oil component of the distillation tower side line is 130-160°C, and the final distillation point is 250-275°C, the initial distillation point of the first coal-based Fischer-Tropsch synthetic fuel oil is 220-240°C, and the final distillation point is 300-320°C. ℃; step S5, subjecting the first fuel oil component of the distillation tower side line to the fourth fractionation to obtain a second coal-based Fischer-Tropsch synthetic fuel oil; subjecting the second fuel oil component of the distillation tower side line to the fifth fractionation to obtain a third coal-based Fischer-Tropsch synthetic fuel oil; wherein the second coal-based Fischer-Tropsch synthetic fuel oil has an initial distillation point of 170-195℃, and a final distillation point of 230-250℃, and the third coal-based Fischer-Tropsch synthetic fuel oil has an initial distillation point of 225-245℃, and a final distillation point of 250-275℃.

[0025] As environmental protection requirements gradually increase, it is particularly important to prepare new energy fuel oil with low sulfur content. Most of the fuel oil reported so far is petroleum-based fuel oil, and there are few reports on coal-based fuel oil, and there are no reports on coal-based Fischer-Tropsch synthetic fuel oil. In the preparation method of coal-based Fischer-Tropsch synthetic fuel oil provided by the present invention, coal is used as raw material, and through the coal indirect liquefaction Fischer-Tropsch synthesis reaction, the coal is gasified by oxygen and water vapor to obtain synthesis gas (H 2The syngas is then reacted under the action of a Fischer-Tropsch synthesis catalyst to generate a Fischer-Tropsch reaction crude oil containing liquid hydrocarbons, waxes, gaseous light hydrocarbons and some organic oxygen-containing compounds. Among them, under the influence of hydrogen in the syngas, the sulfides in the syngas are hydro-cracking, and the sulfur content, acid value and ash content in the crude oil are greatly reduced. Through the process route of the coal indirect liquefaction Fischer-Tropsch synthesis reaction, a clean crude oil with low sulfur content, low acid value and low ash content can be prepared.

[0026] Then, the crude oil is fractionated to obtain Fischer-Tropsch stable heavy oil mainly composed of olefins and alkanes. It should be noted that after the first fractionation, light components such as naphtha are also obtained, which can be used to prepare gasoline.

[0027] Next, the Fischer-Tropsch stable heavy oil is hydrotreated. Through the hydrogenation reaction, the content of unsaturated substances such as olefins in the heavy oil can be effectively reduced. Moreover, since non-hydrocarbon compounds such as sulfur, oxygen, and nitrogen are converted into easily removable hydrogen sulfide, water, and ammonia through hydrogenation, impurities such as sulfur, nitrogen, and oxygen in the heavy oil can be effectively removed, and the heavy oil components can be purified, which is beneficial to improving the yield, quality, and purity of the target product fuel oil. Moreover, since unstable olefins and aromatics are saturated during the hydrotreating process, unstable molecules in the heavy oil can be effectively removed, which is beneficial to improving the stability and reliability of the target product fuel oil. The obtained hydrotreating product is fractionated to obtain a hydrotreating diesel fraction, a hydrotreating tail oil, and a hydrotreating gasoline fraction with a boiling point of <195°C. The hydrotreating diesel fraction is sent to a distillation tower for distillation. The hydrotreating gasoline fraction with a boiling point of <195°C mainly contains light components such as naphtha, which can be used to prepare gasoline.

[0028] Then the hydrorefined tail oil is subjected to hydrocracking. During the hydrocracking process, heavy hydrocarbons such as long-chain alkanes in the hydrorefined tail oil can be decomposed into light hydrocarbon molecules such as high-octane gasoline, high-olefin content liquefied petroleum gas, benzene, and ethylene, which is beneficial to improving the fluidity and flammability of the fuel oil and increasing the product value. Moreover, during the hydrocracking process, the sulfur, oxygen, and nitrogen in the molecules are removed during the chain breaking process of the long-chain molecules, which is beneficial to reducing the sulfur content and aromatic content in the fuel oil, thereby reducing the emission of harmful gases during the combustion of the fuel oil and reducing pollution to the environment. The obtained hydrocracking product is fractionated to obtain hydrocracking tail oil, hydrocracking gasoline fraction, and hydrocracking diesel fraction. The obtained hydrocracking diesel fraction with an initial boiling point of 160-180°C and a final boiling point of 280-350°C is sent to a distillation tower for distillation.

[0029] It should be noted that the hydrocracked diesel fraction with an initial boiling point of 160-180°C and a final boiling point of 280-350°C is sent for distillation to prepare fuel oil because the diesel fraction in this distillation section has the characteristics of a moderate flash point, which improves the combustion performance and stability of the fuel oil and is conducive to reducing the energy consumption of subsequent processes. If the final boiling point of the hydrocracked diesel fraction is higher than 350°C, the product flash point is high, the combustion is incomplete, and the ash content after combustion is high. If the initial boiling point of the hydrorefined diesel fraction is lower than 160°C, the product flash point will be reduced, which will bring safety hazards to transportation and use. The hydrocracking gasoline fraction mainly contains light components such as naphtha, which can be used to prepare gasoline. The hydrocracking tail oil mainly contains long-chain alkanes, which can be used to prepare lubricating oil base oil.

[0030] After the diesel fraction is distilled, the gasoline component at the top of the distillation tower, the first fuel oil component of the distillation tower side line, the second fuel oil component of the distillation tower side line, and the first coal-based Fischer-Tropsch synthetic fuel oil are obtained. Among them, the top component of the distillation tower is mainly rich in light diesel components, which can be used to prepare diesel products such as automotive diesel. The first coal-based Fischer-Tropsch synthetic fuel oil with an initial boiling point of 220-240°C and a final boiling point of 300-320°C has a main component of paraffin. When used as a fuel oil, it has the advantages of high combustion calorific value, safety, stability, and cleanliness.

[0031] In order to fully separate the alkane components with different boiling points and meet the market demand for fuel oils with different flash points, the intermediate product of the distillation tower is separated into two groups of products: the first fuel oil component of the distillation tower side line and the second fuel oil component of the distillation tower side line. The initial boiling point of the first fuel oil component of the distillation tower side line is 120-160°C and the final boiling point is 230-250°C. The main component is paraffin. It is fractionated to obtain the second coal-based Fischer-Tropsch synthetic fuel oil with an initial boiling point of 130-150°C and a final boiling point of 180-200°C. The fuel oil has good combustion performance, safety and stability. If the final boiling point of the second coal-based Fischer-Tropsch synthetic fuel oil is higher than 200°C, the product flash point is high, it is not easy to ignite, and the combustion is incomplete. If the initial boiling point of the second coal-based Fischer-Tropsch synthetic fuel oil is lower than 130°C, the product flash point is low, it is easy to ignite, and it is unsafe.

[0032] The initial boiling point of the second fuel oil component of the distillation tower side line is 130-160°C, the final boiling point is 250-275°C, and the main component is paraffin. It is fractionated to obtain the third coal-based Fischer-Tropsch synthetic fuel oil with an initial boiling point of 170-190°C and a final boiling point of 210-230°C. If the final boiling point of the third coal-based Fischer-Tropsch synthetic fuel oil is higher than 230°C, the product flash point is high, which may lead to the phenomenon of difficult ignition and incomplete combustion. If the initial boiling point of the third coal-based Fischer-Tropsch synthetic fuel oil is lower than 170°C, the product flash point is low, easy to ignite, and the safety is poor.

[0033] In summary, coal is subjected to indirect liquefaction, Fischer-Tropsch synthesis reaction, fractionation, hydrorefining, hydrocracking, and fractionation to prepare fuel oil with a total distillation range of 170 to 320°C. The process is simple, has low requirements for raw materials, and has high product quality. Fuel oil has low sulfur, nitrogen, and aromatic content, low acid value, and low ash content. It is a clean and environmentally friendly substitute for furnace fuel oil. Coal is used as raw material, which is rich in resources and has a wide source, and can effectively solve the problem of shortage of fuel oil raw material resources in the existing technology.

[0034] In order to make the raw coal more fully prepare clean, stable and qualified oil products, in a preferred embodiment, in step S1, the preparation step of Fischer-Tropsch synthesis crude oil is: coal is gasified to obtain synthesis gas, and the synthesis gas is subjected to Fischer-Tropsch synthesis reaction to prepare Fischer-Tropsch synthesis crude oil; wherein the synthesis gas includes H 2 , CO, the molar ratio of the two is (1.3-1.9):1; preferably, the reaction temperature of coal gasification is 1200-1750°C; and / or the reaction pressure is 3-5MPa; and / or the coal includes one or more of lignite, bituminous coal and anthracite; and / or the catalyst of the Fischer-Tropsch synthesis reaction includes one or more of Fe-based catalyst, Co-based catalyst, Ni-based catalyst and Ru-based catalyst. Under the above conditions, using coal instead of oil as raw material can greatly reduce dependence on traditional oil resources, more fully promote the transformation of my country's energy structure, and the yield of Fischer-Tropsch synthesis crude oil is higher and the quality is better.

[0035] In order to more fully remove the light oil in the crude oil, thereby being more conducive to increasing the load of subsequent processing steps and further improving the production efficiency of subsequent fuel oil, in a preferred embodiment, in step S1, the first fractionation is carried out in a first distillation tower, the bottom temperature of the first distillation tower is 300-350°C, and the top pressure is 0.1-0.2MPa.

[0036] In order to further reduce the side reactions such as condensation, decarbonization, and methanation, thereby more effectively improving the yield of alkane products and further improving the reaction rate of hydrofining, in a preferred embodiment, in step S2, the reaction temperature of hydrofining is 250-350°C, preferably 260-300°C; and / or the reaction pressure is 2-8MPa, preferably 3-6MPa; and / or the volume space velocity is 0.5-3h -1 , preferably 0.5 to 2 hours -1 ; and / or a hydrogen-to-oil ratio of 200 to 700, preferably 250 to 400.

[0037] In order to further improve the selectivity of alkane products and the reaction rate of hydrofining, in a preferred embodiment, the hydrofining catalyst includes a first carrier and a first active metal component supported on the first carrier; preferably, the mass ratio of the first active metal component to the first carrier is (3-8):1000; and / or the first carrier is one or more of silicon oxide, aluminum oxide and titanium oxide, more preferably aluminum oxide; and / or the first active metal component includes one or more of Co, Pt, Pd, Ni, W and Mo, more preferably Mo-Ni. Under the above conditions, the catalyst has better activity, higher stability, better selectivity for alkane products, can obtain more saturated hydrofining products, and is more conducive to obtaining fuel oil with higher combustion performance.

[0038] In order to remove light oils such as naphtha produced by hydrofining and cut heavy oil components at the same time, in a preferred embodiment, the second fractionation is carried out in the second fractionation tower, and the bottom temperature of the second fractionation tower is 280-350°C, preferably 310-340°C; and / or the top temperature is 100-145°C, preferably 100-130°C; and / or the bottom pressure is 0.1-1.1MPa, preferably 0.2-0.6MPa. Under the above conditions, the product at the top of the second fractionation tower is a gasoline fraction, the product at the bottom is a hydrofining tail oil, and the sideline component is a diesel fraction, which is more conducive to obtaining a fuel oil with better combustion performance.

[0039] In order to further improve the cracking rate of alkanes, isomerization, ring-opening cracking of polycyclic alkanes and polycyclic aromatic hydrocarbons in the hydrocracking reaction, and more effectively prevent severe cracking, thereby more fully improving the selectivity and yield of diesel components, in a preferred embodiment, in step S3, the reaction temperature of hydrocracking is 300-380°C, preferably 300-350°C; and / or the reaction pressure is 2-8MPa, preferably 3-7MPa; and / or the volume space velocity is 0.5-3.5h -1 , preferably 0.5 to 1.5h -1 ; and / or a hydrogen-to-oil ratio of 200 to 800, preferably 200 to 500.

[0040] In order to make the cracking reaction in the hydrocracking product more selective, the cracking reaction yield higher, the diesel fraction output higher, and the content of impurities such as polycyclic aromatic hydrocarbons, sulfur, and nitrogen lower, in a preferred embodiment, the hydrocracking catalyst includes a second carrier and a second active metal component supported on the second carrier; preferably, the mass ratio of the second active metal component to the second carrier is (2-7): 1000; and / or the second carrier is one or more of silicon oxide, aluminum oxide, and titanium oxide, more preferably aluminum oxide; and / or the second active metal component includes one or more of Co, Pt, Pd, Ni, W, and Mo, more preferably Mo-Ni-W. Under the above conditions, the selectivity for the diesel fraction product is better, and a more stable hydrocracking product can be obtained, which is more conducive to obtaining a fuel oil with higher combustion performance and more stability.

[0041] In order to more effectively remove light oils such as naphtha produced by hydrocracking and cut heavy oil components at the same time, in a preferred embodiment, the third fractionation is carried out in the third fractionation tower, and the bottom temperature of the third fractionation tower is 290-360°C, preferably 300-335°C; and / or the top temperature is 100-160°C, preferably 100-140°C; and / or the bottom pressure is 0.1-1.2MPa, preferably 0.1-0.6MPa. Under the above conditions, the product at the top of the third fractionation tower is a gasoline component, the product at the bottom of the tower is a cracking tail oil, and the sideline component is a cracking diesel, which is more conducive to obtaining a fuel oil with better combustion performance.

[0042] In a preferred embodiment, in step S4, the hydrorefined diesel fraction and the hydrocracked diesel fraction are first mixed and then distilled in the same distillation tower; preferably, the mass ratio of the hydrorefined diesel fraction to the hydrocracked diesel fraction is (1-50):1; and / or the hydrorefined diesel fraction and the hydrocracked diesel fraction are distilled in the same distillation tower in a switching feed mode; preferably, the mass ratio of the hydrorefined diesel fraction to the hydrocracked diesel fraction is (1-50):1; and / or the hydrorefined diesel fraction and the hydrocracked diesel fraction are fed into different distillation towers for distillation in an independent feed mode.

[0043] In order to more fully separate and cut the oil components of different distillation sections in the diesel fraction, in a preferred embodiment, in step S4, the top temperature of the distillation tower is 70-110°C, preferably 90°C; and / or the bottom temperature is 200-280°C, preferably 240°C; and / or the top pressure is 15-25kPa, preferably 20kPa. Under the above conditions, the product at the top of the distillation tower is a light diesel fraction, the product at the bottom is a coal-based fuel oil, and the sideline component is a diesel component with a suitable distillation range, which is more conducive to obtaining a fuel oil with better combustion performance.

[0044] For the purpose of more conveniently obtaining fuel oil with a specific distillation range, in a preferred embodiment, in step S5, the fourth fractionation is carried out in the first side-line tower, the bottom temperature of the first side-line tower is 140-190°C; and / or the top temperature is 50-90°C; and / or the bottom pressure is 0.1-1MPa; and / or the fifth fractionation is carried out in the second side-line tower, the bottom temperature of the second side-line tower is 180-220°C; and / or the top temperature is 80-100°C; and / or the bottom pressure is 0.1-1MPa.

[0045] In another typical embodiment of the present invention, a coal-based Fischer-Tropsch synthetic fuel oil is also provided, and the fuel oil is prepared by the above preparation method. Compared with petroleum-based fuel oil, the coal-based Fischer-Tropsch synthetic fuel oil of the present invention has low sulfur and nitrogen content, low acid value, low ash content, and abundant raw material resources and wide sources. It is a clean and environmentally friendly substitute for furnace fuel oil, which can effectively solve the problems of high sulfur content, uncleanness and shortage of raw material resources of fuel oil in the prior art.

[0046] In another typical embodiment of the present invention, there is also provided the use of the above-mentioned coal-based Fischer-Tropsch synthetic fuel oil in domestic burners and / or industrial burners.

[0047] The present application is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in the present application.

[0048] Example 1

[0049] The schematic diagram of the process flow for preparing coal-based Fischer-Tropsch synthetic fuel oil is shown in Figure 1 Step S1: In the Fischer-Tropsch reactor 1 of the coal indirect liquefaction process, raw material A (specifically lignite) is gasified at 1450°C and 4 MPa to obtain synthesis gas (H 2 The molar ratio of CO to CO is 1.75:1), under the action of a slurry bed Fischer-Tropsch synthesis reaction catalyst (iron-based catalyst), the synthesis gas undergoes a Fischer-Tropsch synthesis reaction to obtain a Fischer-Tropsch synthesis crude oil B, and the Fischer-Tropsch synthesis crude oil is sent to a first fractionation tower 2 for a first fractionation, the bottom temperature of the first fractionation tower is 325° C., the top pressure of the tower is 0.15 MPa, and a first oil fraction C (mainly naphtha) with a boiling point of less than 190° C. is obtained at the top of the tower, which can be used to prepare gasoline, and a Fischer-Tropsch stabilized heavy oil D is obtained at the bottom of the tower;

[0050] Step S2, the Fischer-Tropsch stabilized heavy oil D is fed into the hydrotreating reactor 3, and the reaction temperature is 280°C, the reaction pressure is 4.5 MPa, and the volume space velocity is 1.2 h -1, a hydrogen-to-oil ratio of 300, a catalyst being an alumina carrier loaded with Mo-Ni active metal components (wherein the mass ratio of the active component to the carrier is 5:1000), and hydrofining is carried out to obtain a hydrofining product E; the hydrofining product E is sent to a second fractionation tower 4 for a second fractionation, the bottom temperature of the second fractionation tower is 325°C, the top temperature is 120°C, the bottom pressure is 0.4MPa, and a hydrofining gasoline fraction F with a boiling point of <190°C is obtained at the top of the second fractionation tower, which can be used to prepare qualified gasoline products, a hydrofining diesel fraction G with an initial boiling point of 165°C and a final boiling point of 320°C is obtained at the side line, and a hydrofining tail oil H with a boiling point >350°C is obtained at the bottom of the tower;

[0051] Step S3, the hydrorefined tail oil H is sent to the hydrocracking reactor 5, and the reaction temperature is 325°C, the reaction pressure is 5MPa, and the volume space velocity is 1h -1 , a hydrogen-to-oil ratio of 350, and a catalyst being an alumina carrier loaded with Mo-Ni-W active metal components (wherein the mass ratio of the active components to the carrier is 4:1000), to carry out hydrocracking to obtain a hydrocracking product I; the hydrocracking product I is sent to a third fractionation tower 6 for a third fractionation, the bottom temperature of the third fractionation tower is 310°C, the top temperature is 125°C, the bottom pressure is 0.35MPa, and a hydrocracking gasoline fraction J with a boiling point of <190°C is obtained at the top of the third fractionation tower, which can be used to prepare qualified gasoline products, a hydrocracking diesel fraction K with an initial boiling point of 170°C and a final boiling point of 300°C is obtained at the side line, and a hydrocracking tail oil L with a boiling point of >345°C is obtained at the bottom of the tower, which can be used to prepare lubricating oil and other products;

[0052] Step S4, sending the hydrofined diesel fraction G and the hydrocracking diesel fraction K into the storage tank 7 for mixing, the mass ratio of the hydrofined diesel fraction to the hydrocracking diesel fraction is 1:1, and a mixed fraction M is obtained, and then the mixed fraction M is sent to the distillation tower 9 through the feed pump 8 for distillation, the top temperature of the distillation tower is 90°C, the bottom temperature is 240°C, the top pressure is 20kPa, and the second oil fraction N (mainly light diesel) with a boiling point of less than 180°C is obtained at the top of the distillation tower, which can be used to prepare synthetic diesel products, etc., and the side line obtains the first fuel oil component O of the distillation tower side line with an initial boiling point of 140°C and a final boiling point of 240°C, and the second fuel oil component P of the distillation tower side line with an initial boiling point of 150°C and a final boiling point of 260°C, and the first coal-based Fischer-Tropsch synthetic fuel oil Q with an initial boiling point of 230°C and a final boiling point of 310°C is obtained at the bottom of the tower;

[0053] Step S5, sending the first fuel oil component O from the side line of the distillation tower to the first side line tower 10 for the fourth fractionation, the bottom temperature of the first side line tower is 165°C, the top temperature is 75°C, the bottom pressure is 0.5MPa, and the third oil component R (mainly light diesel) with a boiling point of less than 180°C is obtained at the top of the tower, which can be used to prepare diesel products, and the second coal-based Fischer-Tropsch synthetic fuel oil S with an initial distillation point of 180°C and a final distillation point of 240°C is obtained at the bottom of the tower; sending the second fuel oil component P from the side line of the distillation tower to the second side line tower 11 for the fifth fractionation, the bottom temperature of the second side line tower is 200°C, the top temperature is 95°C, the bottom pressure is 0.6MPa, and the fourth oil component T (mainly light diesel) with a boiling point of less than 200°C is obtained at the top of the tower, which can be used to prepare diesel products, and the third coal-based Fischer-Tropsch synthetic fuel oil U with an initial distillation point of 235°C and a final distillation point of 265°C is obtained at the bottom of the tower.

[0054] The first coal-based Fischer-Tropsch synthetic fuel oil Q, the second coal-based Fischer-Tropsch synthetic fuel oil S and the third coal-based Fischer-Tropsch synthetic fuel oil U can be used in burners and / or industrial burners, respectively.

[0055] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 1.

[0056] Example 2

[0057] The only difference from Example 1 is:

[0058] In step S1, the raw material is bituminous coal; H 2 The molar ratio of CO is 1.3:1, the reaction temperature of coal gasification is 1200°C; the reaction pressure is 5MPa; the catalyst for the Fischer-Tropsch synthesis reaction is an Fe-based catalyst; the bottom temperature of the first distillation tower is 350°C, the top pressure is 0.1MPa, the first oil fraction with a boiling point of <185°C is obtained at the top of the tower, and the Fischer-Tropsch stable heavy oil is obtained at the bottom of the tower.

[0059] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 2.

[0060] Example 3

[0061] The only difference from Example 1 is:

[0062] In step S1, the raw material is bituminous coal; H 2 The molar ratio of CO is 1.9:1, the reaction temperature of coal gasification is 1750°C; the reaction pressure is 3MPa; the catalyst for the Fischer-Tropsch synthesis reaction is a Co-based catalyst; the bottom temperature of the first distillation tower is 300°C, the top pressure is 0.2MPa, the first oil fraction with a boiling point of <190°C is obtained at the top of the tower, and the Fischer-Tropsch stable heavy oil is obtained at the bottom of the tower.

[0063] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 3.

[0064] Example 4

[0065] The only difference from Example 1 is:

[0066] In step S2, the reaction temperature is 260°C, the reaction pressure is 6 MPa, and the volume space velocity is 0.5 h -1 , a hydrogen-to-oil ratio of 250, a catalyst being a silica carrier loaded with a Co active metal component (the mass ratio of the active component to the carrier being 3:1000), and hydrotreating is carried out; the bottom temperature of the second fractionation tower is 310°C, the top temperature is 100°C, the bottom pressure is 0.2MPa, a hydrotreating gasoline fraction with a boiling point of <190°C is obtained at the top of the second fractionation tower, a hydrotreating diesel fraction with an initial distillation point of 170°C and a final distillation point of 320°C is obtained at the side line, and a hydrotreating tail oil with a boiling point of >355°C is obtained at the bottom of the tower.

[0067] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 4.

[0068] Example 5

[0069] The only difference from Example 1 is:

[0070] In step S2, the reaction temperature is 300°C, the reaction pressure is 3 MPa, and the volume space velocity is 2 h -1 , a hydrogen-to-oil ratio of 400, a catalyst being a silica carrier loaded with Co active metal component (the mass ratio of the active component to the carrier being 8:1000), and hydrotreating is carried out; the bottom temperature of the second fractionation tower is 340°C, the top temperature is 130°C, the bottom pressure is 0.6MPa, a hydrotreating gasoline fraction with a boiling point of <185°C is obtained at the top of the second fractionation tower, a hydrotreating diesel fraction with an initial distillation point of 160°C and a final distillation point of 330°C is obtained at the side line, and a hydrotreating tail oil with a boiling point of >350°C is obtained at the bottom of the tower.

[0071] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 5.

[0072] Example 6

[0073] The only difference from Example 1 is:

[0074] In step S2, the reaction temperature is 250°C, the reaction pressure is 8 MPa, and the volume space velocity is 0.5 h -1 , a hydrogen-to-oil ratio of 700, a catalyst being a titanium oxide carrier loaded with a Co active metal component (the mass ratio of the active component to the carrier being 5:1000), and hydrotreating is carried out; the bottom temperature of the second fractionation tower is 280°C, the top temperature is 145°C, the bottom pressure is 0.1MPa, a hydrotreating gasoline fraction with a boiling point of <190°C is obtained at the top of the second fractionation tower, a hydrotreating diesel fraction with an initial distillation point of 175°C and a final distillation point of 325°C is obtained at the side line, and a hydrotreating tail oil with a boiling point of >360°C is obtained at the bottom of the tower.

[0075] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 6.

[0076] Example 7

[0077] The only difference from Example 1 is:

[0078] In step S2, the reaction temperature is 350°C, the reaction pressure is 2 MPa, and the volume space velocity is 3 h -1 , a hydrogen-to-oil ratio of 200, a catalyst being a titanium oxide carrier loaded with a Co-type metal component (the mass ratio of the active component to the carrier being 5:1000), and hydrotreating is carried out; the bottom temperature of the second fractionation tower is 350°C, the top temperature is 100°C, the bottom pressure is 1.1MPa, a hydrotreating gasoline fraction with a boiling point of <190°C is obtained at the top of the second fractionation tower, a hydrotreating diesel fraction with an initial distillation point of 170°C and a final distillation point of 345°C is obtained at the side line, and a hydrotreating tail oil with a boiling point of >360°C is obtained at the bottom of the tower.

[0079] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 7.

[0080] Example 8

[0081] The only difference from Example 1 is:

[0082] In step S3, the reaction temperature is 300°C, the reaction pressure is 7 MPa, and the volume space velocity is 0.5 h -1, a hydrogen-to-oil ratio of 500, a catalyst being a silica carrier loaded with a Pt active metal component (the mass ratio of the active component to the carrier being 4:1000), and hydrocracking is carried out; the bottom temperature of the third fractionation tower is 300°C, the top temperature is 140°C, the bottom pressure is 0.1MPa, a hydrocracking gasoline fraction with a boiling point of <196°C is obtained at the top of the third fractionation tower, a hydrocracking diesel fraction with an initial distillation point of 172°C and a final distillation point of 346°C is obtained at the side line, and a hydrocracking tail oil with a boiling point of >350°C is obtained at the bottom of the tower.

[0083] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 8.

[0084] Example 9

[0085] The only difference from Example 1 is:

[0086] In step S3, the reaction temperature is 350°C, the reaction pressure is 3 MPa, and the volume space velocity is 1.5 h -1 , a hydrogen-to-oil ratio of 200, a catalyst being a silica carrier loaded with a Pt active metal component (the mass ratio of the active component to the carrier being 4:1000), and hydrocracking is carried out; the bottom temperature of the third fractionation tower is 335°C, the top temperature is 100°C, the bottom pressure is 0.6MPa, a hydrocracking gasoline fraction with a boiling point of <192°C is obtained at the top of the third fractionation tower, a hydrocracking diesel fraction with an initial distillation point of 176°C and a final distillation point of 345°C is obtained at the side line, and a hydrocracking tail oil with a boiling point of >353°C is obtained at the bottom of the tower.

[0087] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 9.

[0088] Example 10

[0089] The only difference from Example 1 is:

[0090] In step S3, the reaction temperature is 300°C, the reaction pressure is 8 MPa, and the volume space velocity is 0.5 h -1 , a hydrogen-to-oil ratio of 800, a catalyst being a silica carrier loaded with a Pd active metal component (the mass ratio of the active component to the carrier being 2:1000), and hydrocracking is carried out; the bottom temperature of the third fractionation tower is 290°C, the top temperature is 160°C, the bottom pressure is 0.1MPa, a hydrocracking gasoline fraction with a boiling point of <190°C is obtained at the top of the third fractionation tower, a hydrocracking diesel fraction with an initial distillation point of 178°C and a final distillation point of 348°C is obtained at the side line, and a hydrocracking tail oil with a boiling point of >355°C is obtained at the bottom of the tower.

[0091] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 10.

[0092] Embodiment 11

[0093] The only difference from Example 1 is:

[0094] In step S3, the reaction temperature is 380°C, the reaction pressure is 2 MPa, and the volume space velocity is 3.5 h -1 , a hydrogen-to-oil ratio of 200, a catalyst being a silica carrier loaded with a Pd active metal component (the mass ratio of the active component to the carrier being 7:1000), and hydrocracking is carried out; the bottom temperature of the third fractionation tower is 360°C, the top temperature is 100°C, the bottom pressure is 1.2MPa, a hydrocracking gasoline fraction with a boiling point of <195°C is obtained at the top of the third fractionation tower, a hydrocracking diesel fraction with an initial distillation point of 180°C and a final distillation point of 350°C is obtained at the side line, and a hydrocracking tail oil with a boiling point of >358°C is obtained at the bottom of the tower.

[0095] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 11.

[0096] Example 12

[0097] The only difference from Example 1 is:

[0098] In step S4, the mass ratio of the hydrorefined diesel fraction to the hydrocracking diesel fraction is 50:1, the top temperature of the distillation tower is 70°C, the bottom temperature is 280°C, the top pressure is 15kPa, and the second oil component with a boiling point of less than 160°C is obtained at the top of the distillation tower, and the first fuel oil component of the distillation tower side line with an initial distillation point of 160°C and a final distillation point of 235°C and the second fuel oil component of the distillation tower side line with an initial distillation point of 160°C and a final distillation point of 255°C are obtained at the side line, and the first coal-based Fischer-Tropsch synthetic fuel oil with an initial distillation point of 225°C and a final distillation point of 305°C is obtained at the bottom of the tower.

[0099] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 12.

[0100] Example 13

[0101] The only difference from Example 1 is:

[0102] In step S4, the mass ratio of the hydrorefined diesel fraction to the hydrocracking diesel fraction is 1:50, the top temperature of the distillation tower is 110°C, the bottom temperature is 200°C, the top pressure is 25kPa, and the second oil component with a boiling point of <155°C is obtained from the top of the distillation tower, and the first fuel oil component of the distillation tower side line with an initial distillation point of 155°C and a final distillation point of 245°C and the second fuel oil component of the distillation tower side line with an initial distillation point of 160°C and a final distillation point of 270°C are obtained from the side line, and the first coal-based Fischer-Tropsch synthetic fuel oil with an initial distillation point of 235°C and a final distillation point of 315°C is obtained from the bottom of the tower.

[0103] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 13.

[0104] Embodiment 14

[0105] The only difference from Example 1 is:

[0106] In step S4, the hydrofined diesel fraction and the hydrocracking diesel fraction are distilled in the same distillation tower in a switching feeding mode. Specifically, the switching feeding means that after the hydrofined diesel fraction is fed for 1 hour, the feeding is stopped, and then the hydrocracking diesel fraction is fed for 1 hour, and the feeding is continuous in sequence. The mass ratio of the hydrofined diesel fraction and the hydrocracking diesel fraction is 1:1, and the second oil fraction with a boiling point of less than 160°C is obtained at the top of the distillation tower, and the first fuel oil component of the distillation tower side line with an initial boiling point of 160°C and a final boiling point of 238°C is obtained at the side line, and the second fuel oil component of the distillation tower side line with an initial boiling point of 160°C and a final boiling point of 260°C is obtained at the bottom of the tower, and the first coal-based Fischer-Tropsch synthetic fuel oil with an initial boiling point of 228°C and a final boiling point of 309°C is obtained.

[0107] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 14.

[0108] Embodiment 15

[0109] The only difference from Example 1 is:

[0110] In step S4, the hydrorefined diesel fraction and the hydrocracking diesel fraction are fed into different distillation towers for distillation in an independent feeding manner. Specifically, independent feeding means that only the hydrorefined diesel fraction or the hydrocracking diesel fraction is fed in one cycle, and the second oil fraction with a boiling point of less than 160°C is obtained at the top of the two distillation towers, and the first fuel oil component of the distillation tower side line with an initial distillation point of 160°C and a final distillation point of 237°C and the second fuel oil component of the distillation tower side line with an initial distillation point of 153°C and a final distillation point of 260°C are obtained at the side line, and the first coal-based Fischer-Tropsch synthetic fuel oil with an initial distillation point of 232°C and a final distillation point of 313°C is obtained at the bottom of the tower.

[0111] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 15.

[0112] Example 16

[0113] The only difference from Example 1 is:

[0114] Step S5, the bottom temperature of the first side-line tower is 140°C, the top temperature is 50°C, the bottom pressure is 1MPa, the third oil component with a boiling point of <180°C is obtained at the top, and the second coal-based Fischer-Tropsch synthetic fuel oil with an initial distillation point of 178°C and a final distillation point of 242°C is obtained at the bottom; the bottom temperature of the second side-line tower is 220°C, the top temperature is 100°C, the bottom pressure is 0.1MPa, the fourth oil component with a boiling point of <185°C is obtained at the top, and the third coal-based Fischer-Tropsch synthetic fuel oil with an initial distillation point of 232°C and a final distillation point of 262°C is obtained at the bottom.

[0115] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 16.

[0116] Embodiment 17

[0117] The only difference from Example 1 is:

[0118] Step S5, the bottom temperature of the first side-line tower is 190°C, the top temperature is 90°C, the bottom pressure is 0.1MPa, the third oil component with a boiling point of <185°C is obtained at the top, and the second coal-based Fischer-Tropsch synthetic fuel oil with an initial distillation point of 183°C and a final distillation point of 247°C is obtained at the bottom; the bottom temperature of the second side-line tower is 180°C, the top temperature is 80°C, the bottom pressure is 1MPa, the fourth oil component with a boiling point of <190°C is obtained at the top, and the third coal-based Fischer-Tropsch synthetic fuel oil with an initial distillation point of 238°C and a final distillation point of 258°C is obtained at the bottom.

[0119] The test results of the physical and chemical properties of the prepared first coal-based Fischer-Tropsch synthetic fuel oil, the second coal-based Fischer-Tropsch synthetic fuel oil and the third coal-based Fischer-Tropsch synthetic fuel oil are shown in Table 17.

[0120] Test method:

[0121] Flash point: Tested in accordance with GB / T 261-2021.

[0122] Kinematic viscosity: Tested in accordance with GB / T 265-1988.

[0123] Aromatic content: Tested in accordance with NB / SH / T 0913-2015.

[0124] Pour point: Tested in accordance with GB / T 3535-2006.

[0125] Color: Tested in accordance with GB / T 3555-2006.

[0126] Copper sheet corrosion: Tested in accordance with GB / T 5096-2017.

[0127] Bromine index: Tested in accordance with SH / T 0630-1996.

[0128] Table 1

[0129]

[0130]

[0131] Table 2

[0132]

[0133] Table 3

[0134]

[0135] Table 4

[0136]

[0137]

[0138] Table 5

[0139]

[0140] Table 6

[0141]

[0142]

[0143] Table 7

[0144]

[0145] Table 8

[0146]

[0147]

[0148] Table 9

[0149]

[0150] Table 10

[0151]

[0152]

[0153] Table 11

[0154]

[0155] Table 12

[0156]

[0157]

[0158] Table 13

[0159]

[0160] Table 14

[0161]

[0162]

[0163] Table 15

[0164]

[0165] Table 16

[0166]

[0167] Table 17

[0168]

[0169]

[0170] As can be seen from the above, the present invention prepares three types of fuel oils by fractionating, hydrofining, hydrocracking and fractionating the crude oil of coal indirect liquefaction. Compared with petroleum-based fuel oil, coal-based Fischer-Tropsch synthetic fuel oil has low sulfur and nitrogen content, low acid value and low ash content, and is a clean and environmentally friendly alternative to furnace fuel oil.

[0171] It can be seen that when all process parameters are within the preferred range of the present invention, the coal-based Fischer-Tropsch synthetic fuel oil has lower sulfur and nitrogen content, lower acid value and less ash content.

[0172] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing coal-based Fischer-Tropsch synthetic fuel oil, It is characterized in that The preparation method comprises the following steps: Step S1, using coal as raw material, preparing Fischer-Tropsch synthesis crude oil through coal indirect liquefaction Fischer-Tropsch synthesis reaction, and performing a first fractionation on the Fischer-Tropsch synthesis crude oil to obtain Fischer-Tropsch stable heavy oil; Step S2, hydrofining the Fischer-Tropsch stable heavy oil to obtain a hydrofining product; performing a second fractionation on the hydrofining product to obtain a hydrofining diesel fraction, a hydrofining tail oil, and a hydrofining gasoline fraction with a boiling point of less than 195°C; Step S3, hydrocracking the hydrorefined tail oil to obtain a hydrocracking product; performing a third fractionation on the hydrocracking product to obtain a hydrocracking tail oil, a hydrocracking gasoline fraction and a hydrocracking diesel fraction; wherein the initial distillation point of the hydrocracking diesel fraction is 160-180° C., and the final distillation point is 280-350° C.; Step S4, sending the hydrorefined diesel fraction and the hydrocracked diesel fraction into a distillation tower for distillation to obtain a light diesel component at the top of the distillation tower, a first fuel oil component on the distillation tower side line, a second fuel oil component on the distillation tower side line, and a first coal-based Fischer-Tropsch synthetic fuel oil; wherein the first fuel oil component on the distillation tower side line has an initial distillation point of 120 to 160° C. and a final distillation point of 230 to 250° C., the second fuel oil component on the distillation tower side line has an initial distillation point of 130 to 160° C. and a final distillation point of 250 to 275° C., and the first coal-based Fischer-Tropsch synthetic fuel oil has an initial distillation point of 220 to 240° C. and a final distillation point of 300 to 320° C.; Step S5, subjecting the first fuel oil component of the distillation tower side line to a fourth fractionation to obtain a second coal-based Fischer-Tropsch synthetic fuel oil; subjecting the second fuel oil component of the distillation tower side line to a fifth fractionation to obtain a third coal-based Fischer-Tropsch synthetic fuel oil; wherein the second coal-based Fischer-Tropsch synthetic fuel oil has an initial distillation point of 170-195°C and a final distillation point of 230-250°C, and the third coal-based Fischer-Tropsch synthetic fuel oil has an initial distillation point of 225-245°C and a final distillation point of 250-275°C.

2. The preparation method according to claim 1, It is characterized in that In the step S1, The preparation steps of the Fischer-Tropsch synthesis crude oil are: coal is gasified to obtain synthesis gas, and the synthesis gas is subjected to a Fischer-Tropsch synthesis reaction to prepare the Fischer-Tropsch synthesis crude oil; wherein the synthesis gas includes H 2 , CO, the molar ratio of the two is (1.3-1.9):1; Preferably, the reaction temperature of the coal gasification is 1200-1750°C; and / or the reaction pressure is 3-5 MPa; and / or The coal comprises one or more of lignite, bituminous coal and anthracite; and / or The catalyst for the Fischer-Tropsch synthesis reaction includes one or more of a Fe-based catalyst, a Co-based catalyst, a Ni-based catalyst and a Ru-based catalyst.

3. The preparation method according to claim 1 or 2, It is characterized in that In the step S1, The first fractionation is carried out in a first distillation tower, the bottom temperature of the first distillation tower is 300-350° C., and the top pressure of the tower is 0.1-0.2 MPa.

4. The preparation method according to any one of claims 1 to 3, It is characterized in that In the step S2, The reaction temperature of the hydrofining is 250-350°C, preferably 260-300°C; and / or the reaction pressure is 2-8MPa, preferably 3-6MPa; and / or the volume space velocity is 0.5-3h -1 , preferably 0.5 to 2 hours -1 ; and / or a hydrogen-to-oil ratio of 200 to 700, preferably 250 to 400; and / or The hydrotreating catalyst comprises a first carrier and a first active metal component supported on the first carrier; preferably, the mass ratio of the first active metal component to the first carrier is (3-8):1000; and / or the first carrier comprises one or more of silicon oxide, aluminum oxide and titanium oxide; and / or the first active metal component comprises one or more of Co, Pt, Pd, Ni, W and Mo; and / or The second fractionation is carried out in a second distillation tower, the bottom temperature of the second distillation tower is 280-350°C, preferably 310-340°C; and / or the top temperature is 100-145°C, preferably 100-130°C; and / or the bottom pressure is 0.1-1.1MPa, preferably 0.2-0.6MPa.

5. The preparation method according to any one of claims 1 to 4, It is characterized in that In the step S3, The reaction temperature of the hydrocracking is 300-380°C, preferably 300-350°C; and / or the reaction pressure is 2-8MPa, preferably 3-7MPa; and / or the volume space velocity is 0.5-3.5h -1 , preferably 0.5 to 1.5h -1 ; and / or a hydrogen-to-oil ratio of 200 to 800, preferably 200 to 500; and / or The hydrocracking catalyst comprises a second carrier and a second active metal component supported on the second carrier; preferably, the mass ratio of the second active metal component to the second carrier is (2-7):1000; and / or the second carrier comprises one or more of silicon oxide, aluminum oxide and titanium oxide; and / or the second active metal component comprises one or more of Co, Pt, Pd, Ni, W and Mo; and / or The third fractionation is carried out in a third distillation tower, the bottom temperature of the third distillation tower is 290-360°C, preferably 300-335°C; and / or the top temperature is 100-160°C, preferably 100-140°C; and / or the bottom pressure is 0.1-1.2MPa, preferably 0.1-0.6MPa.

6. The preparation method according to any one of claims 1 to 5, It is characterized in that In the step S4, The hydrofined diesel fraction and the hydrocracked diesel fraction are first mixed and then distilled in the same distillation tower; preferably, the mass ratio of the hydrofined diesel fraction to the hydrocracked diesel fraction is (1-50):1; and / or The hydrofined diesel fraction and the hydrocracked diesel fraction are distilled in the same distillation tower in a switching feed mode; preferably, the mass ratio of the hydrofined diesel fraction to the hydrocracked diesel fraction is (1-50):1; and / or The hydrofined diesel fraction and the hydrocracking diesel fraction are fed into different distillation towers in an independent manner for distillation.

7. The preparation method according to any one of claims 1 to 6, It is characterized in that In the step S4, The top temperature of the distillation tower is 70-110° C.; and / or the bottom temperature is 200-280° C.; and / or the top pressure is 15-25 kPa.

8. The preparation method according to any one of claims 1 to 7, It is characterized in that In the step S5, The fourth fractionation is carried out in the first side-line tower, the bottom temperature of the first side-line tower is 140-190° C.; and / or the top temperature is 50-90° C.; and / or the bottom pressure is 0.1-1 MPa; and / or The fifth fractionation is carried out in a second side-line tower, the bottom temperature of the second side-line tower is 180-220° C.; and / or the top temperature is 80-100° C.; and / or the bottom pressure is 0.1-1 MPa.

9. A coal-based Fischer-Tropsch synthetic fuel oil, It is characterized in that The method is prepared according to any one of claims 1 to 8.

10. Use of the coal-based Fischer-Tropsch synthetic fuel oil according to claim 9 in domestic burners and / or industrial burners.

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