CN109988615B

CN109988615B - Flexible wax oil hydrotreating process

Info

Publication number: CN109988615B
Application number: CN201711468997.3A
Authority: CN
Inventors: 刘涛; 李宝忠; 张学辉; 彭绍忠; 崔哲; 乔凯
Original assignee: China Petroleum and Chemical Corp; Sinopec Dalian Research Institute of Petroleum and Petrochemicals
Current assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Priority date: 2017-12-29
Filing date: 2017-12-29
Publication date: 2021-07-09
Anticipated expiration: 2037-12-29
Also published as: CN109988615A

Abstract

The invention discloses a flexible wax oil hydrotreating process. Mixing a wax oil raw material and hydrogen, then feeding the mixture into a first hydrotreating reactor, and dividing the material passing through an upper hydrotreating catalyst bed into two strands; one stream of materials is pumped out of the first hydrotreating reactor through the middle of the bed layer and is mixed with LCO to enter a second hydrotreating reactor for hydrogenation reaction; and the other material continuously flows downwards through a hydrotreating catalyst bed layer at the lower part, and the obtained first hydrotreating reaction material and the second hydrotreating reaction material are subjected to gas-liquid separation and fractionation to obtain naphtha, diesel oil, hydrogenation heavy fraction and the like. The invention provides a flexible hydrotreatment process for flexibly processing different raw oil on a set of hydrotreater to produce high-quality catalytic cracking raw material, which can fully utilize the heat carried by part of first hydrotreatment material to realize the coupling operation of a first hydrotreatment reactor and a second hydrotreatment reactor.

Description

Flexible wax oil hydrotreating process

Technical Field

The invention belongs to the field of petroleum refining, and particularly relates to a flexible hydrotreating process for flexibly producing high-quality catalytic cracking raw materials by using wax oil and LCO as raw materials.

Background

Fluid Catalytic Cracking (FCC) is one of the important means for the conversion of heavy oil into light oil, but with the deterioration and the heavy conversion of the catalytic cracking processing raw material, the operation conditions are more and more strict, the yield of light products and the product properties are poor, and the hydrotreating technology of the catalytic cracking raw material can not only remove the contents of sulfur, nitrogen, metal and other impurities, but also improve the cracking performance of the feeding material, reduce the operation severity of FCC, improve the product distribution, improve the selectivity of target products, reduce the yield of dry gas and coke, improve the economy of an FCC device, reduce the sulfur content of the target products, reduce the SOx and NOx content in the regeneration flue gas, and the like. The catalytic cracking Light Cycle Oil (LCO) contains a certain content of sulfur and nitrogen, both of which exist in the form of organic compounds, and has high aromatic hydrocarbon content, especially the content of aromatic hydrocarbons with more than two rings, and the LCO is generally directly circulated back to a catalytic cracking device for continuous conversion, or enters a hydrotreating device for hydrogenation and then enters the catalytic cracking device, or enters other devices for processing or directly serves as a product.

CN103773495A, CN101875856A, CN102465035A and CN001896192A disclose a process technology for blending LCO in a wax oil hydrotreating process, and mainly aim at producing high-quality catalytic cracking raw materials or realizing clean production of a catalytic cracking device by a coupling technology for circulating LCO between a wax oil hydrotreating device and the catalytic cracking device. However, since the wax oil and the LCO are directly hydrogenated after being mixed, the hydrogenation depth of the LCO cannot be effectively controlled, and only the sulfur content or the nitrogen content of the mixed hydrogenation product (catalytic cracking raw material) can be used as a control target, which is not beneficial to effectively controlling the production of high-quality gasoline by the LCO.

In summary, compared with the existing LCO hydrogenation technology and wax oil hydrogenation technology, the LCO is usually directly blended into the wax oil hydrogenation device for hydrogenation, the hydrogenated wax oil and the hydrogenated LCO obtained after mixed hydrogenation are jointly used as the raw material of the catalytic cracking device, i.e., the LCO is hydrogenated and then returned to the catalytic cracking device.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a flexible wax oil hydrotreating process, namely, a part of reactant flow is extracted from the middle part of a first hydrotreating reactor, and the wax oil raw oil and the LCO raw oil are subjected to a combined process of two hydrotreating reaction zones to produce high-quality catalytic cracking raw materials.

The flexible wax oil hydrotreating process of the invention comprises the following steps:

a. the method comprises the following steps that firstly, wax oil raw oil passes through a hydrotreating catalyst bed layer on the upper part of a first hydrotreating reactor under a hydrotreating condition to obtain a first hydrotreating material flow, the part of the material flow is divided into two parts, and one part of the material flow is pumped out of the first hydrotreating reactor;

b. the rest part of the first hydrotreating material flow in the step a continuously passes through a lower hydrotreating catalyst bed layer of a first hydrotreating reactor under the hydrotreating condition, and the obtained material flow generated by the first hydrotreating reactor is separated and fractionated (or stripped) to obtain a first hydrogenation gas product, a first hydrogenation naphtha product, first hydrogenation diesel oil and first hydrogenation heavy fraction;

c. and b, mixing the first hydrotreating material flow extracted from the first hydrotreating reactor in the step a with LCO, and allowing the mixture to pass through a hydrotreating catalyst bed of a second hydrotreating reactor under a hydrotreating condition to obtain a material flow generated by the second hydrotreating reactor, and separating and fractionating (or stripping) the material flow to obtain a second hydrogenated gas product, a second hydrogenated naphtha product, second hydrogenated diesel oil and second hydrogenated heavy fraction.

According to the flexible wax oil hydrotreating process of the invention, the separation and fractionation processes in step b and step c preferably share a set of separation and fractionation system. Wherein, the high-pressure hydrogen-rich gas obtained in the separation process is respectively recycled or recycled after being mixed.

The requirements of product quality, environmental protection, process operation and the like all limit the properties of raw oil of a catalytic cracking unit, particularly the sulfur content, and the distribution and properties of catalytic cracking products are greatly different due to different raw oil compositions; the research shows that: the aromatic hydrocarbon hydrogenation saturation depth of LCO has great influence on the quality of catalytic cracking gasoline products, particularly monocyclic aromatic hydrocarbon in gasoline is a high-octane component, the octane number of the catalytic cracking gasoline can be increased by increasing the content of the monocyclic aromatic hydrocarbon in hydrogenated LCO, the hydrogenation difficulty is reduced because the extracted first hydrotreating material flow is subjected to partial hydrogenation reaction, so that the first hydrotreating material flow can meet the aim requirements of hydrodesulfurization and hydrodenitrogenation under a mild operation condition after being mixed with LCO, the hydrogenation depth of LCO can be just controlled at the moment, namely, the bicyclic aromatic hydrocarbon and polycyclic aromatic hydrocarbon in LCO are hydrogenated to the monocyclic aromatic hydrocarbon on the premise of meeting the sulfur content, but not the polycyclic aromatic hydrocarbon is generated due to excessive hydrogenation depth, or the bicyclic aromatic hydrocarbon is generated due to insufficient hydrogenation depth, so that the content of the aromatic hydrocarbon in the catalytic cracking gasoline can be increased when the hydrotreated products enter a catalytic cracking device again, thereby improving the octane number of the catalytic cracking gasoline.

Compared with the prior art, the flexible wax oil hydrotreating process has the advantages that:

1. in the present invention, the first hydroprocessing reactor comprises at least two hydroprocessing catalyst beds. Through the extraction step of the first treatment material arranged in the middle of the bed layer of the first hydrotreatment reactor, the effective distribution of the first hydrotreatment material strand can be realized without special operation, and then the obtained material is subjected to a hydrogenation combination process, so that a high-quality target product can be produced. At the same time, it is technically easy to extract the reactant stream in the middle of the reactor bed. In the prior art, LCO is usually directly mixed with wax oil raw oil and then enters a hydrotreating reactor to directly produce catalytic cracking raw material.

2. According to the invention, the first hydrotreating material flow extracting device is arranged in the middle of the catalyst bed layer of the first hydrotreating reactor, the first hydrotreating material flow of the wax oil raw material after the first hydrotreating is extracted out of the reactor, and the first hydrotreating material flow and the LCO are mixed and sent to the second hydrotreating reactor which is arranged independently for hydrogenation reaction, and because the impurities such as sulfur, nitrogen and the like in a part of the wax oil raw material are removed by hydrogenation, the difficulty of further hydrogenation is reduced, so that the reaction condition can be controlled to control the hydrogenation depth of the LCO, namely the hydrogenation saturation depth of the polycyclic aromatic hydrocarbon and the polycyclic aromatic hydrocarbon in the LCO, and the hydrogenation is controlled to hydrogenate the polycyclic aromatic hydrocarbon to the monocyclic aromatic hydrocarbon as far as possible, so that the reaction difficulty is reduced or the aromatic hydrocarbon content in the catalytic cracking gasoline is improved when the hydrogenated LCO is subjected to catalytic cracking again, and the octane number of the gasoline is improved.

3. In the invention, the extracted material flow obtained in the middle of the hydrogenation pretreatment catalyst bed layer of the first hydrotreatment reactor has very high temperature and pressure, and can directly enter a second hydrotreatment reactor newly arranged for reaction after being mixed with LCO, thereby fully utilizing the heat carried by the part of the hydrotreatment material and realizing the coupling operation of the first hydrotreatment reactor and the second hydrotreatment reactor.

4. In the invention, the operating pressure of the first hydrotreating reaction system is the same as that of the second hydrotreating reaction system, so that the high-pressure hydrogen-rich gas in the two systems can use one set of hydrogen desulfurization system and one set of hydrogen circulation system, and if the two systems share one set of separation and fractionation (or stripping) system, the equipment investment and the operating cost can be greatly saved.

Drawings

Fig. 1 is a schematic flow chart of the principle of the present invention.

Fig. 2 is another schematic flow chart of the present invention.

Wherein: 1-wax oil raw oil, 2-first hydrotreatment reactor, 3-first hydrotreatment extraction material flow, 4-LCO raw oil, 5-first hydrotreatment reactor recycle hydrogen, 6-first hydrotreatment reactor generated material flow, 7-second hydrotreatment reactor, 8-second hydrotreatment reactor generated material flow, 9-second high-pressure separator, 10-second fractionating tower, 11-second hydrotreatment naphtha, 12-second hydrotreatment diesel oil, 13-second hydrotreatment heavy fraction oil, 14-second high-pressure separator hydrogen-rich gas, 15-make-up hydrogen, 16-first high-pressure separator, 17-first fractionating tower, 18-first hydrotreatment naphtha, 19-first hydrotreatment diesel oil, 20-first hydrotreatment heavy fraction oil, 21-first high-pressure separator hydrogen-rich gas, 22-mixed high-pressure separator, 23-mixed fractionating tower, 24-mixed hydrogenation naphtha, 25-mixed hydrogenation diesel oil, 26-mixed hydrogenation heavy distillate oil and 27-mixed high-pressure separator hydrogen-rich gas.

Detailed Description

The initial boiling point of the wax oil raw material in the step a is 100-400 ℃, and the final boiling point is 405-650 ℃. The wax oil raw material oil can be one of straight-run wax oil, coking wax oil, deasphalted oil and the like obtained by petroleum processing, one of coal tar, coal direct liquefaction oil, coal indirect liquefaction oil, synthetic oil, shale oil and the like obtained from coal, and can also be mixed oil of a plurality of the coal tar, the coal direct liquefaction oil, the coal indirect liquefaction oil, the synthetic oil and the shale oil.

Step a, step b and step cThe hydrotreating catalyst is a conventional wax oil hydrotreating catalyst. Generally, metals in a VIB group and/or a VIII group are used as active components, alumina or silicon-containing alumina is used as a carrier, the metals in the VIB group are generally Mo and/or W, and the metals in the VIII group are generally Co and/or Ni. Based on the weight of the catalyst, the content of the VIB group metal is 10-35 wt% calculated by oxide, the content of the VIII group metal is 3-15 wt% calculated by oxide, and the properties are as follows: the specific surface area is 100 to 650m²The pore volume is 0.15 to 0.6 mL/g. The main catalysts comprise hydrogenation pretreatment catalysts such as 3936, 3996, FF-16, FF-26, FF-36, FF-46 and FF-56 series developed by the petrochemical research institute, and can also be similar catalysts with functions developed by domestic and foreign catalyst companies, such as HC-K, HC-P of UOP company, TK-555 and TK-565 of Topsoe company, KF-847 and KF-848 of Akzo company, and the like. The hydrotreating catalyst described in step a, step b and step c may use the same catalyst or different catalysts.

The operation condition of the hydrotreatment in the step a can adopt the conventional hydrotreatment condition, generally the reaction pressure is 3.0MPa to 19.0MPa, the reaction temperature is 300 ℃ to 450 ℃, and the liquid hourly volume space velocity is 0.2h^-1～6.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

The inlet of the first hydrotreatment reactor in the step a, namely the top of the upper hydrogenation catalyst bed layer, is filled with a hydrogenation protective agent, the hydrogenation protective agent is a conventional hydrogenation protective agent, and the protective agent bed layer is generally graded by using 2 or more protective agent varieties. The operation condition of the protective agent can adopt the conventional operation condition, generally the reaction pressure is 3.0MPa to 19.0MPa, the reaction temperature is 280 ℃ to 420 ℃, and the liquid hourly volume space velocity is 0.5h^-1～20.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

And c, the mass proportion of the part of the extracted material flow in the step a in the liquid phase to the wax oil raw oil is 5-95 wt%, and preferably 10-60 wt%.

The operation condition of the step b can adopt the conventional hydrogenation operation condition, generally the reaction pressure is 3.0MPa to 19.0MPa, the reaction temperature is 300 ℃ to 450 ℃, and the liquid hourly space velocity is 0.2h^-1～6.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

The separation described in step b generally comprises separating two parts, a first hydroprocessing high-pressure separator and a low-pressure separator. Wherein the high-pressure separator separates to obtain the hydrogen-rich gas and liquid under high pressure, and the liquid separated by the high-pressure separator enters the low-pressure separator. The low pressure separator separates the high pressure liquid product to yield a hydrocarbon-rich gas and a low pressure liquid product. The hydrocarbon-rich gas is separated to obtain the required hydrotreating gas product.

The fractionation (or stripping) described in step b is carried out in a hydrotreating fractionator (or stripper) system. The low pressure liquid product is fractionated in a fractionating tower to obtain a first hydrotreated naphtha product, a first hydrotreated diesel and a first hydrotreated heavy fraction.

And c, the LCO raw material is light cycle oil of a catalytic cracking unit, the initial boiling point of the LCO raw material is 100-200 ℃, and the final boiling point of the LCO raw material is 320-400 ℃. The LCO raw oil can also be mixed with one or more of diesel fractions with high aromatic hydrocarbon content, such as coking diesel, ethylene cracking tar, coal tar and the like.

The operation conditions of the step c can adopt the conventional hydrogenation operation conditions, generally the reaction pressure is 3.0MPa to 19.0MPa, the reaction temperature is 300 ℃ to 450 ℃, the preferred temperature is 320 ℃ to 410 ℃, and the liquid hourly volume space velocity is 0.2h^-1～6.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

The separation described in step c is performed in a second hydroprocessing high pressure separator and a low pressure separator. The high-pressure hydrogen-rich gas and the liquid are separated by the high-pressure hydrotreating separator, and the liquid separated by the high-pressure separator enters the low-pressure separator. The low pressure separator separates the high pressure liquid product to yield a hydrocarbon-rich gas and a low pressure liquid product. The hydrocarbon-rich gas is separated to produce the desired second hydroprocessed gaseous product.

The fractionation (or stripping) described in step c is carried out in a second hydroprocessmg fractionator (or stripper) system. And fractionating the low-pressure liquid product in a fractionating tower to obtain a second hydrotreated naphtha product, second hydrotreated diesel oil and second hydrogenated heavy distillate oil.

The first and second hydrotreated gas products described in step b and step c may be used alone or mixed as a mixed gas product.

The first hydrotreated naphtha product and the second hydrotreated naphtha product described in step b and step c may be used as separate products or may be mixed to form a mixed naphtha product.

The first hydrotreated diesel oil and the second hydrotreated diesel oil in the step b and the step c can be used as products independently or can be mixed to be used as raw oil of a catalytic cracking unit.

And c, mixing the first hydrotreated heavy fraction and the second hydrotreated heavy fraction in the steps b and c to be used as raw oil of the catalytic cracking unit.

The separation described in steps b and c can be carried out in a mixed hydroprocessing high-pressure separator and a mixed low-pressure separator, i.e. the streams of the two hydroprocessing reactors are mixed into one and the same hydroprocessing high-pressure separator and one and the same low-pressure separator. The mixed hydrogenation high-pressure separator is used for separating to obtain mixed hydrogenation high-pressure hydrogen-rich gas and mixed liquid, and the mixed liquid obtained by separation of the mixed hydrogenation high-pressure separator enters the mixed low-pressure separator. The mixed low pressure separator separates the high pressure liquid product to produce a mixed hydrocarbon-rich gas and a mixed low pressure liquid product. The mixed hydrocarbon-rich gas is separated to obtain the required mixed hydrotreating gas product.

The fractionation (or stripping) described in steps b and c may be performed in a hybrid hydrotreating fractionator (or hybrid stripper) system. And fractionating the mixed low-pressure liquid product in a mixed fractionating tower to obtain a mixed hydrotreated naphtha product, mixed hydrotreated diesel oil and mixed hydrotreated heavy distillate oil.

The mixed high-pressure hydrogen-rich gas in the step b and the step c can be directly used as recycle hydrogen, and can also be recycled after hydrogen sulfide is removed by a recycle hydrogen desulfurization system.

In the invention, the hydrogenation process in the second hydrotreatment reactor comprises two reaction stages which are sequentially carried out, wherein the first reaction stage is carried out in a catalyst bed layer A containing a hydrotreatment catalyst, and the second reaction stage is carried out in a catalyst bed layer B containing a hydrotreatment catalyst. The method can also comprise the process of cutting the LCO raw oil into light fraction and heavy fraction, wherein the cutting temperature is 245-300 ℃. And B, mixing the heavy fraction with the first hydrogenation pretreatment material flow extracted in the step a, and then passing through a catalyst bed layer A, and mixing the hydrogenation treatment material flow obtained by the catalyst bed layer A with the light fraction, and then passing through a catalyst bed layer B.

Further, the reaction temperature y of the second reaction stage in the second hydrotreatment reactor₂Below the reaction temperature y of the first reaction stage₁Preferably y₂Ratio y₁The lower temperature is 5-20 ℃.

The heavy fraction obtained by cutting the LCO raw oil is mainly polycyclic aromatic hydrocarbon and can achieve the purpose of controlling the hydrogenation depth of the aromatic hydrocarbon through more hydrogenation catalyst reactions, and the double-ring aromatic hydrocarbon in the light fraction can achieve the purpose of controlling the hydrogenation depth of the aromatic hydrocarbon with the heavy fraction through less hydrogenation catalyst reactions, namely, the hydrogenated LCO meets the sulfur content, simultaneously the double-ring aromatic hydrocarbon and the polycyclic aromatic hydrocarbon are properly hydrogenated to the single-ring aromatic hydrocarbon, the gasoline can meet the requirement of the sulfur content after further catalytic cracking, and the octane number of the gasoline can be improved. In addition, the catalyst bed layer B in the second hydrotreating reactor is operated at the temperature lower than that of the catalyst bed layer A, and the hydrogenation saturation conversion of the bicyclic aromatic hydrocarbon into the monocyclic aromatic hydrocarbon is facilitated.

In the invention, the catalyst bed layer A and the catalyst bed layer B can be arranged in one hydrotreating reactor, or can be respectively arranged in more than two hydrotreating reactors. The first mode is preferably employed in the present invention.

With reference to fig. 1, the method of the present invention is as follows: the method comprises the steps of firstly mixing wax oil raw oil 1 with recycle hydrogen 5, feeding the mixture into a first hydrotreating reactor 2, pumping out a hydrotreating pumped-out material flow 3 from a reactant flow passing through a first hydrotreating catalyst bed, continuously feeding the material flow after pumping out the hydrotreating pumped-out material flow 3 into a hydrotreating catalyst bed at the lower part, feeding the pumped-out hydrotreating pumped-out material flow 3 and LCO raw oil 4 into a second hydrotreating reactor 7 after mixing, feeding a generated material flow 8 passing through the hydrotreating catalyst bed into a second high-pressure separator 9 for gas-liquid separation, feeding the separated liquid into a second fractionating tower 10 for fractionating to obtain second hydrotreated naphtha 11, second hydrotreated diesel 12, second hydrotreated heavy fraction 13, and a first hydrotreating reactor produced material flow 6 into a first high-pressure separator 16 for gas-liquid separation, and feeding the separated liquid into a first fractionating tower 17 for fractionating to obtain first hydrotreated naphtha 18, The second hydrogen-rich gas 14 obtained by separating the first hydrotreated diesel oil 19, the first hydrotreated heavy fraction 20 and the second high-pressure separator 9 is mixed with the first hydrogen-rich gas 21 obtained by separating the first high-pressure separator 16, then the mixture is pressurized by a recycle hydrogen compressor and then is further mixed with make-up hydrogen 15 to be used as recycle hydrogen.

The embodiments and effects of the present invention are described below by way of examples.

Examples 1 to 4

The protective agents FZC-100, FZC-105 and FZC106 are hydrogenation protective agents developed and produced by the smooth petrochemical research institute of the China petrochemical industry, Inc.; the catalyst FF-24 is a hydrotreating catalyst developed and produced by the research institute of petrochemical industry, which is comforted by the company Limited in petrochemical industry of China.

TABLE 1 essential Properties of wax oil base stocks

	Wax oil 1	Wax oil 2	LCO
				Density, g/cm³	0.904	0.937	0.935
Fraction range, C	325～550	345～620	156~380
				Sulfur content, wt.%	2.2	1.5	1.1
Nitrogen content, wt%	0.103	0.245	0.08
				Aromatic content, wt.%	—	—	91.6

TABLE 2 Process conditions

Table 2 Process conditions

TABLE 3 test results

Wherein the cutting temperature of the LCO light fraction and the heavy fraction is 270 ℃.

It can be seen from the examples that, by adopting the flexible wax oil hydrotreating process of the invention, a high-quality catalytic cracking raw material is provided by extracting a part of the reaction material flow from the first hydrotreating reactor, mixing the extracted material flow with LCO for hydrotreating to produce a high-quality catalytic cracking raw material, and the remaining hydrotreated material flow after the material flow is extracted is continuously hydrotreated to produce high-quality naphtha, hydrogenated diesel oil and hydrogenated heavy fraction, and the production mode is flexible.

Claims

1. A flexible wax oil hydrotreating process, comprising the steps of:

b. the rest part of the first hydrotreating material flow in the step a continuously passes through a lower hydrotreating catalyst bed layer of a first hydrotreating reactor under the hydrotreating condition, and the obtained material flow generated by the first hydrotreating reactor is subjected to separation, fractionation or stripping to obtain a first hydrogenation gas product, a first hydrogenation naphtha product, first hydrogenation diesel oil and first hydrogenation heavy fraction;

c. providing a second hydrotreating reactor, wherein the second hydrotreating reactor comprises two reaction stages which are sequentially carried out and are respectively carried out in a catalyst bed layer A and a catalyst bed layer B containing hydrotreating catalysts; cutting LCO raw oil into light fraction and heavy fraction, wherein the cutting temperature is 245-300 ℃; and (B) mixing the obtained LCO heavy fraction with the first hydrogenation pretreatment material flow extracted in the step (a) and then passing through a catalyst bed layer A, mixing the hydrogenation treatment material flow obtained by the catalyst bed layer A with the obtained LCO light fraction and then passing through a catalyst bed layer B, and separating, fractionating or stripping the obtained material flow generated by the second hydrogenation treatment reactor to obtain a second hydrogenation gas product, a second hydrogenation naphtha product, second hydrogenation diesel oil and second hydrogenation heavy fraction.

2. The hydrotreating process of claim 1 wherein the separation and fractionation steps in steps b and c share a single separation and fractionation system.

3. The hydrotreating process according to claim 1, wherein the wax oil feedstock has an initial boiling point of 100 to 400 ℃ and an end boiling point of 405 to 650 ℃.

4. The hydrotreating process according to claim 3, characterized in that the wax oil feedstock is at least one selected from the group consisting of virgin wax oil, coker wax oil, deasphalted oil, coal tar, coal direct liquefaction oil, coal indirect liquefaction oil, synthetic oil and shale oil.

5. The hydrotreating process of claim 1 in which the LCO has an initial boiling point of 100 to 200 ℃ and an end point of 320 to 400 ℃.

6. The hydroprocessing process of claim 1, wherein said LCO further incorporates at least one of coker gas oil, ethylene pyrolysis tar, and coal tar.

7. The hydrotreating process as claimed in claim 1, wherein the hydrotreating catalyst has VIB group and/or VIII group metal as active component and alumina or silica-containing alumina as carrier; based on the weight of the catalyst, the content of the VIB group metal is 10-35 wt% calculated by oxide, and the content of the VIII group metal is 3-15 wt% calculated by oxide; the properties are as follows: the specific surface area is 100 to 650m²The pore volume is 0.15 to 0.6 mL/g.

8. The hydroprocessing process of claim 1, wherein the hydroprocessed strands of step aThe parts are as follows: the reaction pressure is 3.0MPa to 19.0MPa, the reaction temperature is 300 ℃ to 450 ℃, and the liquid hourly volume space velocity is 0.2h^-1～6.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

9. The hydrotreating process according to claim 1, characterized in that the part of the stream withdrawn in step a is 5 to 95 wt% in terms of liquid phase based on the wax oil feedstock.

10. The hydrotreating process according to claim 1, characterized in that the hydrotreating conditions in step b are: the reaction pressure is 3.0MPa to 19.0MPa, the reaction temperature is 300 ℃ to 450 ℃, and the liquid hourly volume space velocity is 0.2h^-1～6.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

11. The hydrotreating process according to claim 1, characterized in that the conditions of hydrotreating in step c are: the reaction pressure is 3.0MPa to 19.0MPa, the reaction temperature is 300 ℃ to 450 ℃, and the liquid hourly volume space velocity is 0.2h^-1～6.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

12. The hydrotreating process according to claim 1, characterized in that the reaction temperature y of the catalyst bed B₂Lower than the reaction temperature y of the catalyst bed A₁。

13. The hydrotreating process of claim 12, characterized in that y is₂Ratio y₁The lower temperature is 5-20 ℃.

14. The hydrotreating process according to claim 9, characterized in that the part of the stream withdrawn in step a is 10 to 60 wt% in terms of liquid phase based on the wax oil feedstock.