CN103305266A

CN103305266A - Coal-based military fuel and preparation method thereof

Info

Publication number: CN103305266A
Application number: CN2013102415777A
Authority: CN
Inventors: 张晓静; 李培霖; 胡发亭; 朱肖曼; 王勇; 石智杰; 赵渊; 杜淑凤; 吴艳; 赵鹏; 孙竟晔; 陈来夫; 常秋连
Original assignee: China Coal Research Institute CCRI
Current assignee: China Coal Research Institute CCRI
Priority date: 2013-06-18
Filing date: 2013-06-18
Publication date: 2013-09-18
Anticipated expiration: 2033-06-18
Also published as: CN103305266B

Abstract

The invention discloses a coal-based military fuel and a preparation method thereof. The method comprises the steps of: (1) carrying out distillation cutting on raw oil so as to at least obtain a light fraction and a heavy oil fraction, wherein the raw oil is one or more of oil produced through direct coal liquefaction, oil produced through refining coal and oil together, and pretreated coal tar; (2) enabling the light fraction to enter a hydrofining reactor for hydrofining; and (3) enabling oil produced through hydrofining to enter a fractionating tower for fractionating after the oil is subjected to cooling and gas-liquid separation, thereby obtaining the military fuel. According to the method, the scope of application is wide, the process flow is reasonable, the raw material utilization ratio is high, the varieties of products are multiple, and the operation is flexible, so that the method can be applied to the mass production of various special oils.

Description

Preparation method of coal-based military fuel and prepared military fuel

Technical Field

The invention belongs to the field of coal chemical industry, relates to a deep processing and utilizing method of coal-based oil products, in particular to a method for producing various military fuels by utilizing coal tar, and is also suitable for producing various military fuels by using oil generated by direct liquefaction of coal and oil generated by co-refining kerosene.

Background

Today, the world situation is unstable and the possibility of local wars and outbreaks of emergencies is increasing. In future war, military oil guarantee has become one of the key links for determining the victory or defeat of war, and in military oil consumption, the consumption of fuel is far greater than that of other oil. At present, military fuels in China are all petroleum-based fuels, and resources in China are characterized by being rich in coal, poor in oil and deficient in gas, the external dependence of petroleum is over 50%, and the international oil price is continuously increased. China has abundant coal resources, and the technology for preparing military fuel by using coal-based derivative oil is beneficial to reducing the dependence on imported petroleum and has important strategic significance for ensuring the energy safety of China.

The coal derived oil mainly comprises oil products produced in a series of coal chemical engineering process taking coal as a source, such as direct coal liquefaction oil, kerosene co-refining generated oil, indirect coal liquefaction synthetic oil, coal gasification and coal carbonization pyrolysis byproduct coal tar and the like. The main component of the coal indirect liquefied oil is normal paraffin, so that the blending component of the jet fuel can be prepared only after mild cracking (isomerization); in the aspect of preparing jet fuel by using coal direct liquefied oil, research works are carried out by enterprises and scientific research units, and the jet fuel has patent technologies of preparing civil jet fuel, military jet fuel with large specific gravity and the like, but the product is single in type.

Coal tar is a byproduct liquid product in the processes of dry distillation pyrolysis and gasification of coal, and can be divided into the following types according to different dry distillation pyrolysis and gasification temperatures and production methods: high-temperature coal tar (900-1000 ℃), medium-temperature coal tar (700-900 ℃), medium-low temperature coal tar (600-800 ℃), and low-temperature coal tar (450-650 ℃). Any coal tar is a complex organic mixture mainly composed of aromatic compounds, and the components of the coal tar are tens of thousands of substances. In recent years, the yield of coal tar is increasing continuously as a liquid alternative energy source, the processing and utilizing technology of the coal tar is developing rapidly, and the deep processing and the high-efficiency utilization of the coal tar are deeply concerned and valued by petrochemical industry and coal chemical industry. At present, the conventional processing methods of coal tar mainly comprise the following steps:

(1) the method is used for extracting chemical products such as phenol, benzene, naphthalene, anthracene and the like, but the residue after the extraction of the chemicals still has the pollution problem;

(2) the coal tar light fraction or the whole fraction is subjected to delayed coking to obtain light fraction, and is subjected to fixed bed hydrofining and hydrocracking to produce common gasoline and diesel oil products, so that the added value of the products is low;

(3) the blended fuel is directly used as poor fuel crude fuel, so that the environmental pollution is serious, and the precious coal tar resource is greatly wasted. Compared with petroleum, the coal tar has the unique properties of high content of aromatic hydrocarbon and cyclane, and is more suitable for producing special civil/military oil.

The military fuel mainly refers to military aviation fuel, rocket fuel, missile fuel, battlefield general oil and the like, the jet fuel is also called aviation kerosene and is a main fuel used by a military aircraft, and the distillation range is generally between 130 and 280 ℃. The main indexes of jet fuel are density and freezing point, and the requirement is high density and low freezing point. The jet fuel produced in China at present has four varieties, wherein the jet fuel No. 3 (RP-3) has moderate distillation range, slightly high flash point and safe and reliable use, so the jet fuel is widely applied to domestic and foreign civil airliners and military aircrafts, is the most common fuel for international airlines at present, and has wide market prospect.

With the continuous service of high-performance airplanes in China, the demand for jet fuel with high density, high energy and good stability is more and more urgent. High-density jet fuel is a liquid hydrocarbon fuel with high density, high volume heat value and high performance, and is a hot spot of research in various countries at present. After more than 10 years of research, the national binsifaria energy research institute has found that traditional petroleum-based fuels can hardly withstand temperatures above 450 ℃, while coal-based fuels can withstand temperatures as high as 500 ℃ without carbon formation, so that coal-based jet fuels are a necessary trend in the development of future aviation jet fuels.

The aerospace technology has extremely important significance for national defense construction, and the carrier rocket plays an extremely important role. Launch vehicles have been widely used to launch various satellites, manned spacecraft, space stations, and other spacecraft. Rocket propellants (also called as fuel agents and fuels) are divided into liquid and solid, the solid propellant has small specific thrust and is easy to burn and interrupt or extinguish, and a large amount of smoke generated easily pollutes the environment, so that liquid fuels are mostly adopted by carrier rockets. The liquid propellant commonly used by the rocket mainly comprises kerosene, alcohol, hydrazine fuels (anhydrous hydrazine, methyl hydrazine and unsym-dimethyl hydrazine) and liquid hydrogen; the alcohol has low combustion efficiency, easy spontaneous combustion and strong corrosivity; hydrazine fuels have strong toxicity, serious pollution and high price and are gradually eliminated; liquid hydrogen is expensive and not easy to store.

In the face of higher requirements of the international commercial satellite launching market and future satellite launching and deep space exploration in China, factors such as environmental protection and launching safety are considered, and a new generation of carrier rocket with high thrust, high reliability, low cost, no toxicity and no pollution is developed in China. The new generation of carrier rocket in China named as 'Long-Zheng-Wu' breaks through a plurality of key technologies, enters a substantial development stage, and is expected to realize the first flight in 2014. The new generation rocket engine adopts kerosene/liquid oxygen fuel, and has the advantages that the kerosene is used as a normal-temperature propellant, so that the use is very convenient, and the safety is good; the price of kerosene is low, so that the development cost of an engine and the launching cost of a carrier rocket can be greatly reduced; the success of various research tests and two times of kerosene/liquid oxygen engine hot test runs fully proves that the domestic kerosene can completely meet the use requirements; the fuel is nontoxic liquid, and water and carbon dioxide are basically generated after combustion. The coal tar is a good raw material for producing rocket fuel after deep processing

The missile is generally regarded by all countries and developed rapidly since the world war II comes out. The core of the missile power device is an engine, and the missile engines are various and generally divided into two main types of rocket engines and air-breathing jet engines. Induction jet engines can be further divided into turbojet engines, turbofan jet engines and ramjet engines. The high-density hydrocarbon fuel is storable liquid hydrocarbon fuel with high density and high volume heat value used by missile jet engines (turbines, turbofan engines and ramjets), and mainly comprises large-specific-gravity aviation kerosene, synthetic polycyclic hydrocarbon fuel, high-tension cage hydrocarbon fuel and colloid fuel. The coal tar is very suitable for preparing high-density hydrocarbon fuel after deep hydrogenation.

Different fuels such as gasoline, kerosene, diesel oil and the like are used by military equipment in China at present, and because the fuels of different varieties cannot be mixed, different special facilities have to be adopted for storage, transportation in different modes and filling of different equipment, so that great difficulty is brought to the work of oil material supply. The rapid, efficient, timely and accurate oil guarantee is a prerequisite for winning wars, and in order to improve the oil logistics guarantee efficiency, a battlefield single fuel (also called a battlefield general fuel or a battlefield general oil) plan is proposed in the 80 th century in the United states. After general fuels are used by military transport vehicles, tanks, ships, airplanes and the like, the technical requirements on support personnel are greatly reduced, and the support pressure is reduced and the support system is simplified

US4875992 discloses a process for producing aviation kerosene having a large specific gravity from a fused ring aromatic hydrocarbon and a hydrogenated aromatic hydrocarbon feedstock. The raw materials adopted by the method are oil rich in bicyclic aromatic hydrocarbon and bicyclic hydrogenated aromatic hydrocarbon, and the oil comprises light catalytic cycle oil, coal tar, coal liquefied oil and the like. The raw materials are firstly desulfurized and denitrified in a first stage reaction, then are hydrotreated in a second stage reaction, saturated bicyclic aromatic hydrocarbon and bicyclic hydrogenated aromatic hydrocarbon are selectively hydrogenated to generate naphthenic hydrocarbon and generate low molecular hydrocarbon as little as possible, and the specific gravity index (API DEG) of the obtained aviation kerosene with large specific gravity is between 25 and 35 deg. The method requires that the fraction range of the raw material is 350F-700F degrees, and simultaneously, the raw material contains 85-100% of bicyclic aromatic hydrocarbon and bicyclic hydrogenated aromatic hydrocarbon, so that the method has strict requirements on the raw material.

GB2234518 provides a process for the production of aviation kerosene having a high specific gravity from feedstocks rich in bicyclic, polycyclic aromatic hydrocarbons. The aromatics-rich feedstock can be derived from catalytically cracked light cycle oil, coal tar or shale oil, and the like. Mixing raw oil and hydrogen, feeding the mixture into a first hydrogenation reactor to carry out hydrodesulfurization and denitrification reactions, adopting a fluorine-containing noble metal catalyst to carry out dearomatization in a second reactor,to improve the product quality. In order to ensure the stable activity of the second anti-noble metal catalyst, a separator is needed to generate H between the first hydrogenation reactor and the second reactor₂S，NH₃And separating out.

CN1478867A discloses a process for producing jet fuel from coker distillates. The method is aimed at the raw material of coking diesel oil or coking gasoline and diesel oil, and adopts an acid catalyst containing zeolite to carry out hydrotreating on coking raw oil under proper process conditions, and the jet fuel product can be obtained after the product is fractionated. The method adopts an acid catalyst, has certain requirements on the nitrogen content of raw oil, is not suitable for all coking gasoline and diesel oil raw materials, and has certain difficulty in treating inferior naphthenic base coking distillate oil.

CN101434851A discloses a mixed hydrogenation process of coker gasoline and coking kerosene. The method adopts a proper cutting point by adjusting the operating conditions of a fractionation system of a delayed coking device, the components of the coking gasoline and the coking kerosene are not separated, the coking gasoline and the coking kerosene directly enter a special hydrogenation device for hydrofining, and the coking gasoline and the coking kerosene are mixed and hydrogenated to produce naphtha and aviation kerosene to the maximum extent.

CN102465026A discloses a coking kerosene fraction hydrotreating method. The method takes coking kerosene fraction as raw material, and firstly carries out conventional hydrofining reaction in a first reactor; and (3) enabling the obtained reaction effluent to enter gas stripping hydrogen mixing equipment, removing hydrogen sulfide and ammonia dissolved in the generated oil, mixing the reaction effluent with supplementary hydrogen, enabling the reaction effluent to enter a second reactor to be in contact with a noble metal hydrogenation catalyst, and carrying out deep dearomatization reaction to obtain a product meeting the 3# jet fuel standard.

CN101434864A discloses a hydrogenation modification method of coking light distillate oil. The coking light distillate oil is subjected to hydrofining, stripping and fractionation to obtain naphtha fraction, kerosene fraction and diesel fraction, wherein the kerosene fraction and hydrogen enter a hydro-upgrading reactor, and the obtained liquid product can be used as a high-quality jet fuel component. The initial boiling point of the coking light distillate oil raw material used by the method is 30-70 ℃, and the final boiling point is 320-380 ℃.

CN102304387A discloses a method for producing coal-based high-density jet fuel, which introduces light and medium fractions separated from coal direct liquefaction oil after hydrotreating by an expansion bed, and then high-density jet fuel which meets jet fuel standards and is separated after deep hydrofining by a fixed bed.

Disclosure of Invention

The invention aims to provide a novel method for producing various military fuels by using coal tar as a raw material and also using oil generated by direct coal liquefaction or oil generated by coal oil co-refining as a raw material.

The method disclosed by the invention comprises the following steps:

1) distilling and cutting raw oil into at least light fraction and heavy oil fraction; the raw oil is one or more of oil generated by directly liquefying coal, oil generated by co-refining kerosene or pretreated coal tar. If the processed raw material is the direct coal liquefaction produced oil or the co-refining kerosene produced oil, the raw material is directly subjected to a distillation separation step without pretreatment to obtain light fraction and heavy fraction. If the processed raw material comprises coal tar, the coal tar is pretreated before entering a distillation device and a hydrogenation device to remove components such as moisture, mechanical impurities and the like in the coal tar, so that the subsequent distillation process and the hydrogenation process can be normally carried out. The invention adopts the conventional method to remove the moisture and solid impurities of the coal tar.

The coal tar is mixed oil of any one or more than two of low-temperature coal tar, medium-temperature coal tar and high-temperature coal tar in any proportion.

The dehydration of the coal tar is divided into two steps of primary dehydration and final dehydration, wherein the primary dehydration adopts a heating standing dehydration method, namely the tar is heated and insulated in a storage tank by a coil pipe at 30-90 ℃ and stands for more than 36 hours, and the water content of the tar can be dehydrated to 2% -3%; or an ultracentrifuge can be adopted to carry out preliminary dehydration on the tar, and the water content of the tar can be dehydrated to 1% -2%. The final dehydration can adopt an intermittent kettle dehydration method, a tubular furnace dehydration method, a film dehydration method, a chemical demulsification method and the like, and the water content of the finally dehydrated coal tar can be reduced to be below 0.5 percent.

The removal of mechanical impurities in the coal tar can adopt a method combining solvent extraction and a settling centrifuge, and can also independently remove the impurities by using a super three-phase centrifugal separation device, and the content of the purified solid impurities in the coal tar can be less than 0.3 percent by using the method.

Preferably, the distillation process is atmospheric distillation or vacuum distillation;

preferably, the cutting temperature of the light oil fraction and the heavy oil fraction is between 280 ℃ and 450 ℃; depending on the oil source, the light oil fraction may comprise a diesel fraction.

Preferably, the raw oil is cut to obtain a phenol oil fraction or a naphtha fraction; extracting the phenol oil fraction or naphtha fraction by a phenol extraction unit to obtain dephenolized oil and crude phenol, and adding the dephenolized oil into a hydrofining reactor for hydrogenation, for example, mixing the dephenolized oil with light fraction to be used as raw oil for producing military fuel for hydrogenation upgrading; and (4) additionally treating the heavy distillate oil.

For coal tar with high phenol content, phenol oil fraction or naphtha distillate oil, the coal tar, the phenol oil fraction or the naphtha distillate oil contains considerable phenol compounds, and if the coal tar, the phenol oil fraction or the naphtha distillate oil is directly hydrogenated without phenol removal, the phenol compounds with high added values are converted into aromatic hydrocarbons to enter final products, so that the product price is reduced, and the hydrogen consumption in the process is increased.

Extracting phenolic compounds in the phenol oil fraction or naphtha distillate oil by adopting an alkali liquor washing method or a solvent extraction method to obtain a crude phenol product and dephenolized oil, and feeding the dephenolized oil to a hydrofining unit. When phenol is extracted by using an alkali liquor washing method, the alkali washing temperature is 30-60 ℃, the alkali washing time is 0.2-1.5 min, the alkali liquor concentration is 7-13%, the water/oil mass ratio is 0.6-1.2,by using CO₂Acidifying the sodium phenolate salt; when the solvent extraction method is used for extracting phenol, the extractant is ethylene glycol or glycerol, the extraction temperature is normal temperature, the stirring time is 10-40 min, and the highest phenol removal rate can reach 96%.

For coal tar with lower phenol content, the phenol extraction operation is not considered, and the coal tar or coal directly liquefied to generate oil or coal oil co-refined to generate oil is distilled, separated and cut into light distillate oil and heavy distillate oil.

2) And (3) removing harmful impurities, saturated olefin and aromatic hydrocarbon from the light distillate oil through hydrofining, wherein the harmful impurities comprise sulfur, nitrogen and oxygen in the raw oil.

Preferably, the hydrorefining reactor is a fixed bed reactor, the hydrorefining adopts a single-stage or two-stage or multi-stage hydrogenation process, the catalyst takes amorphous alumina and/or silica or a molecular sieve or a mixture thereof as a carrier, the active metal component is VIB or VIII group metal or a combination of the metals, wherein the VIB group metal is preferably Mo or/and W, and the VIII group metal is preferably Co or/and Ni.

Preferably, the hydrofining reaction conditions are as follows: the reaction temperature is 200-440 ℃, the reaction pressure is 6-17 MPa, and the volume space velocity is 0.5-4.0 h^-1The hydrogen-oil ratio is 300-2000.

Preferably, the pore volume of the hydrofining catalyst is more than or equal to 0.4mL/g, and the specific surface area is more than or equal to 120m²(iv) g, bulk density of 0.4 to 1.9Kg/m³The inorganic oxide used by the hydrofining catalyst carrier is alumina, silica, titanium oxide, magnesium oxide or the mixture of the alumina, the silica, the titanium oxide and the magnesium oxide, and the molecular sieve is ZSM zeolite, L-type zeolite, Y-type zeolite, Beta zeolite or the mixture of the ZSM zeolite, the L-type zeolite, the Y-type zeolite and the Beta zeolite; the non-noble metal active component is nickel, cobalt, molybdenum, tungsten or the combination of the nickel, the cobalt, the molybdenum and the tungsten, and the noble metal active component is platinum, palladium or the combination of the platinum and the palladium; the total content of non-noble metal components in the catalyst is 20-80 wt% calculated by oxides, and the total content of noble metal components in the catalyst is 0.1-20 wt% calculated by oxides.

(3) Fractionation of the product

And (2) after the hydrorefining generated oil is cooled and subjected to gas-liquid separation, the obtained hydrogenated liquid-phase material enters a fractionating tower for fractionating, namely, the hydrogenated liquid-phase material is fractionated into refined naphtha fraction, jet fuel fraction or/and battlefield general fuel fraction, rocket kerosene fraction or/and large-specific-gravity jet fuel fraction or/and refined diesel fraction according to different product purposes. The battlefield utility fraction comprises a battlefield utility or a battlefield utility base oil.

Preferably, the military fuel further comprises a modifier additive comprising one or more of a flash point improver, a tackifier, an antiwear additive, a density improver, or a pour point depressant.

Preferably, the cutting temperature of the light fraction and the heavy fraction in the distillation separation in the step 1) is between 380-450 ℃, the hydrofined oil enters a fractionating tower after being cooled and subjected to gas-liquid separation, and the hydrogenated liquid phase material is fractionated into refined naphtha fraction, jet fuel fraction or rocket fuel fraction or large-specific-gravity jet fuel fraction or battlefield general fuel fraction, refined diesel fraction, tail oil and the like according to different product purposes; the tail oil needs to be subjected to fixed bed hydrocracking reaction in the following step, and the hydrocracking generated oil enters a hydrofining fractionating tower after being cooled and subjected to gas-liquid separation. And (3) hydrocracking the tail oil through a fixed bed to further hydrocracking macromolecular oil products which are larger than the diesel oil distillation range into micromolecular gasoline and diesel oil fractions.

The naphtha fraction can be used as a reforming raw material to produce aromatic hydrocarbon or high-octane gasoline, and can also be used as an ethylene cracking raw material to produce ethylene; a jet fuel fraction as # 3 jet fuel or # 3 jet fuel base oil; the rocket kerosene fraction is used as a rocket fuel (kerosene for a launch vehicle) or as a base oil for a rocket fuel (kerosene for a launch vehicle). The large specific gravity jet fuel fraction is used as a base oil for a large specific gravity jet fuel (large specific gravity jet kerosene) or a large specific gravity jet fuel (large specific gravity jet kerosene).

When the cutting temperature of the light fraction and the heavy fraction in the distillation separation in the step 1) is less than 380 ℃, the step is not needed, and the tail oil separated in the step (3) needs to be further hydrocracked if the cutting temperature of the light fraction and the heavy fraction in the distillation separation in the step (2) is between 380 ℃ and 450 ℃.

The hydrocracking reactor is a fixed bed reactor, and can adopt single-stage hydrogenation or two-stage or multi-stage hydrogenation process, the catalyst uses amorphous alumina and/or silicon oxide or molecular sieve as carrier, and the active metal component is VIB or VIII group non-noble metal or the combination of the above metal components, wherein the VIB group metal is preferably Mo or/and W, and the VIII group metal is preferably Co or/and Ni. The hydrocracking reaction conditions are as follows: the reaction temperature is 200-450 ℃, the reaction pressure is 6-19 MPa, and the volume space velocity is 0.5-4.0 h^-1The hydrogen-oil ratio is 300-2000.

Wherein,

1) the fractionated fractions can be used to produce # 3 jet fuel:

and analyzing and testing the obtained jet fuel fraction according to the product standard of the 3# jet fuel, wherein if all indexes of the jet fuel fraction can meet the product standard requirements of the 3# jet fuel, the jet fuel fraction can be directly used as the 3# jet fuel product, and if all the indexes can not meet the requirements, the jet fuel fraction can be used as the base oil of the 3# jet fuel, and the jet fuel fraction is properly blended by adopting an additive to meet the product standard requirements of the 3# jet fuel.

2) The fractionated fractions can be used to produce battlefield utility stocks:

according to the current international common practice, the fuel simplification is realized by mainly combining kerosene type and diesel type fuels, so the battlefield general fuel produced by the invention is kerosene and diesel general fuel. The invention uses the obtained indexes of the general oil fraction in the battlefield to meet the product standard requirements of the general oil in the battlefield, the general oil fraction in the battlefield can be directly used as general oil products in the battlefield, if the indexes can not meet the requirements completely, the general oil of kerosene and diesel oil can be produced by adding flash point improving agent or/and tackifier or/and antiwear additive or/and density improving agent and/or pour point depressant.

3) The fractionated fractions can be used to make rocket fuels/heavy jet fuels:

the rocket kerosene fuel has the characteristics of high density, low condensation point, high quality and the like, the composition of the rocket kerosene fuel mainly comprises bicyclic cycloalkanes which account for about 50 percent, and the rocket kerosene fuel comprises alkanes and monocyclic cycloalkanes, and the contents of oxygen-containing compounds, alkenes, tricyclic cycloalkanes and aromatics are less. The invention takes the obtained rocket kerosene fraction as base oil, and produces the rocket kerosene fuel or the jet fuel with large specific gravity by adding a flash point improver or/and a tackifier or/and an antiwear additive or/and a density improver and/or a pour point depressant and other means according to the standards and requirements of rocket fuel (kerosene for a carrier rocket engine) and jet fuel with large specific gravity.

The flash point improver (also called oil product flame retardant) is prepared by compounding various special surfactants, and the addition amount of the flash point improver is 0.1-2 per mill of the oil product; the oil tackifier is polyene, and the addition amount is 0.1-1.5%; the antiwear additive is oil soluble liquid antiwear agent, preferably dialkyl organic salt, and the addition amount is 0.1-2%; the density improver is an organic polymer compound, and the addition amount is 0.1-5%.

The advantages of the invention are mainly embodied in the following points:

1. the method provided by the invention is suitable for low-temperature coal tar, medium-low temperature coal tar and high-temperature coal tar, is also suitable for mixed oil of any two or more kinds of coal tar, can also be suitable for oil generated by co-refining coal direct liquefaction and kerosene, and has a wide range of raw material application.

2. The invention can flexibly adjust the process flow and the product distribution according to the property of the raw oil; the operation of the device and the product types can be flexibly changed according to the supply and demand conditions of military fuel and the market price, and the maximum economic benefit is achieved.

3. In the method provided by the invention, reasonable processing technological process and proper processing depth are adopted, and high value-added products such as No. 3 jet fuel or/and battlefield general fuel or/and rocket kerosene or/and large-specific gravity jet fuel can be produced from light distillate oil of different raw materials by optimizing technological parameters.

4. The military fuel produced by the invention has various types, and can meet the requirements of most modern weapons in China. The 3# jet fuel is suitable for military/civil aircraft, the battlefield general fuel is suitable for military vehicles, tanks, airplanes and the like, the rocket kerosene is suitable for high-thrust carrier rockets, and the large-specific gravity jet fuel is suitable for high-performance military aircrafts, missiles and other weapons.

Drawings

FIG. 1 is a schematic flow diagram of the process of hydrocracking without tail oil according to the present invention;

FIG. 2 is a schematic flow diagram of the process of hydrocracking the tail oil containing the present invention.

Reference symbols of the drawings

1. Fresh hydrogen gas; 2. coal tar; 3. pretreated coal tar; 4. phenol oil fractions or naphtha distillates; 5. diesel distillate; 6. heavy distillate oil; 7. crude phenol; 8. dephenolized oil, 9. light distillate oil, 10. mixed hydrogen; 11. circulating hydrogen; 12. hydrorefining the product; 13. separating the liquid phase from the gas phase; 14. refining the naphtha fraction; 15. a jet fuel fraction or/and a battlefield utility fraction; 16. a rocket kerosene fraction or/and a jet fuel fraction of high specific gravity; 17. refining the diesel oil fraction; 18. tail oil; 19. mixing hydrogen; 20. circulating hydrogen; 21. a tail oil hydrocracking product; 22. gas-liquid separation of liquid phase materials; p1, a coal tar feed pump; v1, pretreating coal tar; p2, a distillation tower feed pump; t1, a distillation separation unit; C1. a fresh hydrogen compressor; D1. a phenol oil phenol extraction unit; p3, a hydrofining unit feed pump; r1. a hydrofining unit; C2. a circulating hydrogen compressor; v2, a hydrofining product gas-liquid separation unit; t2, a product fractionation unit; p4. hydrocracking unit feed pump; r2. hydrocracking unit; C3. a circulating hydrogen compressor; v3. hydrocracking product gas-liquid separating unit.

Detailed Description

The embodiment of tail oil free hydrocracking, as shown in FIG. 1, is illustrated as follows:

coal tar 2 (raw oil) is firstly subjected to dehydration and deslagging (solid impurities) pretreatment in a pretreatment unit V1, and the pretreated coal tar 3 enters a distillation device T1 for distillation and separation. The pretreated coal tar 3 is separated into high phenol-containing distillate oil 4 at the temperature of less than 230 ℃, distillate oil 5 at the temperature of 230-T ℃ (the value of T is 280-380) and heavy distillate oil 6 at the temperature of more than T ℃ (the value of T is 280-380) through distillation, and the heavy distillate oil 6 is treated separately. After the crude phenol product 7 is extracted from the high phenol-containing distillate oil 4 in the phenol extraction unit D1 by an alkali liquor washing method or a solvent extraction method, the residual dephenolized oil 8 and the light distillate oil 9 obtained by mixing the distillate oil 5 with the temperature of 230-T ℃ can be used for preparing the military fuel. The mixed light distillate oil 9 or the light distillate oil 9 directly coming out from the distillation device T1 when the phenol extracting unit is not contained and the mixed hydrogen 10 (the mixture of the fresh hydrogen 1 and the circulating hydrogen 11) are mixed and then enter a hydrofining unit R1 for deep hydrofining, and the hydrofining unit R1 is a single-stage or two-stage or multi-stage hydrogenation process. The hydrofined oil 12 from the hydrofining unit R1 enters a gas-liquid separation device V2, the hydrofined oil 12 is separated into a gas-phase material 11 and a gas-liquid separation liquid phase 13 in the gas-liquid separation device V2, and the gas-phase material 11 is compressed by a recycle hydrogen compressor and then is used as recycle hydrogen to be mixed with fresh hydrogen. The liquid phase 13 of the gas-liquid separation device enters a product fractionation unit T2, and in the product fractionation unit T2, the material is separated into a refined naphtha fraction 14, a jet fuel fraction or/and a battlefield general fuel base oil fraction 15, a rocket kerosene fraction or/and a large specific gravity jet fuel fraction 16 refined diesel fraction 17. If the performance of the obtained various distillate oil meets the product requirements, the distillate oil can be directly used as a product; if the performance can not meet the product requirement, the 3# jet fuel or battlefield general fuel or rocket oil or large-specific gravity jet fuel and other products meeting the requirement are produced by adding a flash point improver or/and a tackifier or/and an antiwear additive or/and a density improver and/or a pour point depressant and the like.

FIG. 2 is an embodiment of hydrocracking tail oil containing heavy distillate 6, illustrated as follows:

the method comprises the steps of firstly carrying out dehydration and deslagging (solid impurity) treatment on raw coal tar oil 2 in a pretreatment unit V1, and enabling pretreated purified coal tar 3 to enter a distillation device T1 for distillation and separation. The pretreated coal tar 3 is separated into high phenol-containing distillate oil 4 at the temperature of less than 230 ℃, light distillate oil 5 at the temperature of 230-T ℃ (the value of T is 380-450), and heavy distillate oil 6 at the temperature of more than T ℃ (the value of T is 380-450) through distillation, and the heavy distillate oil 6 is treated separately. After the crude phenol product 7 is extracted from the high phenol-containing distillate oil 4 in a phenol extraction unit D1 by an alkali liquor washing method or a solvent extraction method, the light distillate oil 9 obtained by mixing the residual dephenolized oil 8 and the distillate oil 5 with the temperature of 230-T ℃ is the raw oil for preparing the military fuel. The mixed raw oil 9 or the light distillate oil 9 directly coming out from the distillation device T1 when the phenol extracting unit is not contained and the mixed hydrogen 10 (the mixture of the fresh hydrogen 1 and the circulating hydrogen 11) are mixed and then enter a hydrofining unit R1 for deep hydrofining, and the hydrofining unit R1 is a single-stage or two-stage or multi-stage hydrogenation process. The hydrofined oil 12 from the hydrofining unit R1 enters a gas-liquid separation device V2, in the gas-liquid separation device V2, the material 12 is separated into a gas-phase material 11 and a gas-liquid separation liquid phase 13, and the gas-phase material 11 is compressed by a recycle hydrogen compressor and then is used as recycle hydrogen to be mixed with fresh hydrogen. The gas-liquid separation liquid phase 13 of the gas-liquid separation device and the gas-liquid separation liquid phase material 22 of the hydrocracking unit gas-liquid separation device V3 are mixed and then enter a product fractionation unit T2, and in the product fractionation unit T2, the mixed material is separated into a refined naphtha fraction 14, a jet fuel fraction or/and a battlefield general fuel base oil fraction 15, a rocket kerosene fraction or/and a large-specific gravity jet fuel fraction 16, a refined diesel oil fraction 17 and tail oil 18. The tail oil 18 and the mixed hydrogen 19 (the mixture of the fresh hydrogen 1 and the circulating hydrogen 20) are mixed and then enter a hydrocracking unit R2 for hydrocracking and light-weight reaction, the hydrocracking unit R2 is a single-stage or two-stage or multi-stage hydrogenation process, a hydrocracking reaction product 21 from a hydrocracking unit R2 enters a gas-liquid separation device V3 and is separated into a gas-phase material and a gas-liquid separation liquid-phase material 22 through gas-liquid separation, the gas-phase material is used as the circulating hydrogen 20 to be mixed with the fresh hydrogen 1, and the gas-liquid separation liquid-phase material 22 is fractionated in a fractionation unit. If the performance of various distillate oil obtained by the product fractionation unit T2 meets the product requirements, the distillate oil can be directly used as a product; if the performance can not meet the product requirement, products such as 3# jet fuel, battlefield general fuel, rocket fuel, large-specific gravity jet fuel and the like which meet the requirement need to be produced by adding a flash point improver or/and a tackifier or/and an antiwear additive or/and a density improver or/and a pour point depressant and the like.

The purpose and advantageous effects of the present invention will be further illustrated by the following examples, but the scope of the present invention is not limited to the following examples.

Example 1

The low-temperature coal tar is used as a raw material, and the purified coal tar after dehydration and slag (solid impurities) removal pretreatment enters a distillation unit and is cut into high-phenol-content distillate oil with the temperature of less than 230 ℃, distillate oil with the temperature of 230-350 ℃ and distillate oil with the temperature of more than 350 ℃. The distillate oil with high phenol content and temperature lower than 230 ℃ is mixed with the distillate oil with the temperature of 230-350 ℃ after the crude phenol product is extracted in a phenol extraction unit, and the mixed light distillate oil is the raw oil for preparing the military fuel, and the properties of the mixed light distillate oil are shown in a table 1. The mixed light distillate oil can be respectively prepared into products such as 3# jet fuel, battlefield general fuel, rocket kerosene, large-specific-gravity jet fuel and the like through deep hydrofining and proper blending, the main process conditions of each process unit are shown in a table 2, and the main properties of each military fuel product are shown in a table 3. The deep hydrorefining adopts a fixed bed hydrogenation experimental device with the feeding amount of 100mL/h and adopts a mode of connecting two reactors in series.

Example 2

The medium-temperature coal tar is used as a raw material, and the purified coal tar after dehydration and slag (solid impurities) removal pretreatment enters a distillation unit and is cut into high-phenol-content distillate oil with the temperature of less than 230 ℃, distillate oil with the temperature of 230-450 ℃ and distillate oil with the temperature of more than 450 ℃. The distillate oil with high phenol content and temperature lower than 230 deg.c is mixed with the distillate oil with temperature of 230-450 deg.c after extracting coarse phenol product in phenol extracting unit, and the mixed light distillate oil is the material oil for preparing military fuel in the present invention and has the properties shown in Table 1. The mixed light distillate oil can be respectively prepared into products such as 3# jet fuel, battlefield general fuel, rocket kerosene, large-specific-gravity jet fuel and the like through deep hydrofining, tail oil hydrocracking, product fractionation and proper processing and blending, the main process conditions of each process unit are shown in table 2, and the main properties of each military fuel product are shown in table 3.

The method is completed on a fixed bed hydrogenation test device with the feeding amount of 100mL/h, and the deep hydrofining adopts a mode of connecting two reactors in series; the tail oil hydrocracking comprises a 100mL/h fixed bed hydrocracking reactor and a fixed bed post-refining reactor with the feeding amount of 100mL/h, and adopts a mode of connecting two reactors in series.

Example 3

The high-temperature coal tar is used as a raw material, and the purified coal tar after dehydration and slag (solid impurities) removal pretreatment enters a distillation unit and is cut into high-phenol-content distillate oil with the temperature of less than 230 ℃, distillate oil with the temperature of 230-365 ℃ and distillate oil with the temperature of more than 365 ℃. The distillate oil with high phenol content and temperature lower than 230 deg.c is mixed with the distillate oil with temperature of 230-365 deg.c after extracting coarse phenol product in phenol extracting unit, and the mixed light distillate oil is the material oil for preparing military fuel in the present invention and has the properties shown in Table 1. The mixed light distillate oil can be respectively prepared into products such as 3# jet fuel, battlefield general fuel, rocket kerosene, large-specific-gravity jet fuel and the like through deep hydrofining and proper processing and blending, the main process conditions of each process unit are shown in a table 2, and the main properties of each military fuel product are shown in a table 3. The deep hydrofining adopts a fixed bed reactor with the feeding amount of 100mL/h and adopts a mode of connecting two reactors in series.

Table 1 examples 1-3 properties of coal tar blends light distillate

Table 2 examples 1-3 main process conditions for each unit

Table 3 example 1 key properties of each military fuel product

Item	3# jet fuel	Universal fuel	Rocket kerosene	Large specific gravity jet fuel
					Density (20 ℃ C.), g/cm³	0.7933	0.8233	0.8239	0.8465
Viscosity (20 ℃ C.), mm²/s	2.105	3.024	2.238	2.168

S,ppm	Less than 3.0	Less than 3.0	Less than 3.0	Less than 3.0
					N,ppm	0.6	0.5	0.1	0.7
Flash point (closed mouth), deg.C	64	64	63	61
					Freezing point, DEG C	Less than-60	Less than-60	Less than-60	Less than-60
Content of naphthenes	Greater than 75	Greater than 75	Greater than 75	Greater than 75
					Arene (FIA), v%	0.5	0.6	0.5	1.1
Distillation range (ASTMD-86), deg.C
					IBP/5%	164/172	166/176	171/182	153/166
10%/20%	178/191	182/202	190/209	172/184
					30%/50%	203/213	210/221	214/222	188/202
70%/80%	219/227	228/231	225/230	215/227
					90%/FBP	236/245	236/256	234/239	236/255

Table 4 example 2 key properties of each military fuel product

Item	3# jet fuel	Universal fuel	Rocket kerosene	Large specific gravity jet fuel
					Density (20 ℃ C.), g/cm³	0.8012	0.8499	0.8442	0.8522
Viscosity (20 ℃ C.), mm²/s	2.201	5.021	3.107	2.355
					S,ppm	<3	<3	<3	<3
N,ppm	Less than 0.5	Less than 0.5	Less than 0.5	Less than 0.5
					Flash point (closed mouth), deg.C	60	61	62	60
Freezing point, DEG C	Less than-60	Less than-60	Less than-60	Less than-60
					Content of naphthenes	Greater than 75	Greater than 75	Greater than 75	Greater than 75
Arene (FIA), v%	0.5	0.3	0.9	1.2
					Distillation range (ASTMD-86), deg.C
IBP/5%	154/168	156/170	173/182	149/164
					10%/20%	175/184	182/190	191/207	169/180
30%/50%	191/205	197/211	215/222	188/199
					70%/80%	219/226	222/231	230/237	208/224

90%/FBP

231/239

236/247

242/245

237/272

Table 5 example 3 key properties of each military fuel product

As can be seen from the data in tables 3 to 5, the military fuel products obtained by the invention all reach or approach the corresponding national military fuel standard, and can be used as military fuel or military fuel blend oil, wherein the main performance index of the large-specific gravity jet fuel is superior to that of the No. 6 jet fuel.

Claims

1. A method of making a coal-based military fuel, comprising:

1) distilling and cutting raw oil into at least light fraction and heavy oil fraction; the raw oil is one or more of oil generated by directly liquefying coal, kerosene co-refined oil or pretreated coal tar;

2) the light fraction enters a hydrofining reactor for hydrofining;

3) and (3) cooling the hydrofined oil, and performing gas-liquid separation to obtain a hydrogenated liquid phase material, and then fractionating the hydrogenated liquid phase material in a fractionating tower to obtain the military fuel.

2. The method of claim 1, wherein the cutting temperature of the light fraction and the heavy oil fraction is between 280 ℃ and 450 ℃.

3. The method according to claim 1, wherein the raw oil cutting also produces a phenol oil fraction or a naphtha fraction; the phenol oil fraction or the naphtha fraction is extracted by a phenol extraction unit to obtain dephenolized oil and crude phenol, and the dephenolized oil enters a hydrofining reactor for hydrofining.

4. The process according to claim 1, characterized in that in step 2), the active metal component of the catalyst used for hydrofinishing is a group VIB or VIII metal, or a combination thereof; the catalyst carrier used for hydrogenation reaction at least comprises one of alumina, silica, titania, magnesia or molecular sieve, and the molecular sieve at least comprises one of ZSM zeolite, L-type zeolite, Y-type zeolite and Beta zeolite.

5. The method according to claim 1 or 4, wherein the reaction temperature in the hydrorefining of the step 2) is 200-440 ℃, the reaction pressure is 6-17 MPa, the volume space velocity is 0.5-4.0 h < -1 >, and the hydrogen-oil ratio is 300-2000.

6. The method according to claim 4, wherein in the step 2), the pore volume of the catalyst used for hydrofining is not less than 0.4mL/g, and the specific surface area is not less than 120m²(iv) g, bulk density of 0.4 to 1.9Kg/m³。

7. The method as claimed in claim 4, wherein in the step 2), the catalyst used for hydrorefining comprises non-noble metal active components and noble metal active components, the non-noble metal active components comprise one or more of nickel, cobalt, molybdenum and tungsten, and the noble metal active components are platinum, palladium or a combination thereof; the total content of non-noble metal components in the catalyst is 20-80 wt% calculated by oxides, and the total content of noble metal components in the catalyst is 0.1-20 wt% calculated by oxides.

8. The method as claimed in claim 1, wherein the cutting temperature of the light fraction and the heavy oil fraction in step 1) is between 380 and 450 ℃, the tail oil obtained by fractionation in step 3) is subjected to fixed bed hydrocracking, and the hydrocracking product oil is cooled and subjected to gas-liquid separation and then enters the fractionating tower.

9. A military fuel made by the method of any of claims 1 to 8.

10. The military fuel of claim 9 further comprising a modifying additive comprising one or more of a flash point improver, a tackifier, an antiwear additive, a density improver, or a pour point depressant.