CN109988601B

CN109988601B - Hydrogenation process for flexibly producing low-condensation-point diesel oil

Info

Publication number: CN109988601B
Application number: CN201711468920.6A
Authority: CN
Inventors: 刘涛; 李宝忠; 彭冲; 刘继华; 刘野; 周勇
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: CN109988601A

Abstract

The invention discloses a hydrogenation process for producing low-condensation-point diesel oil. The diesel raw material enters a hydro-upgrading reactor after being subjected to hydro-refining, and the material passing through a hydro-upgrading catalyst bed is divided into two strands; one material is pumped out of the modification reactor through the middle of the bed layer and enters a hydroisomerization pour point depression catalyst bed layer to carry out pour point depression reaction; the other material continuously flows downwards through a lower hydroisomerization pour point depression catalyst bed layer; and respectively carrying out gas-liquid separation and fractionation on the obtained hydroisomerization pour point depression reaction material and the hydrogenation pour point depression reaction material to obtain diesel products with different specifications. The invention provides a hydrogenation coupling process for simultaneously producing more than two diesel oil products with different specifications on one set of hydrogenation process device for the first time, which can fully utilize the heat carried by partial hydrogenation modified materials to realize the coupling operation of a hydrogenation modified pour point depressing reactor and a hydrogenation pour point depressing reactor.

Description

Hydrogenation process for flexibly producing low-condensation-point diesel oil

Technical Field

The invention belongs to the field of petroleum refining, and particularly relates to a hydrogenation process for flexibly producing a low-condensation-point diesel product.

Background

Increasingly strict environmental regulations require higher and higher quality diesel products, mainly with greater and greater limits on sulfur content, cetane number, density and polycyclic aromatic hydrocarbon content. The inferior diesel oil hydrogenation modification technology can greatly reduce the sulfur content and the aromatic hydrocarbon content of the diesel oil product, reduce the density and improve the cetane number. In addition, in winter, diesel products in cold regions have different limits and requirements on condensation points, and diesel products in China can be divided into specifications of 5#, 0#, -10#, -20#, -35# and-50 # according to the condensation points. The pour point of the diesel can be effectively reduced by the hydrogenation pour point depressing technology.

The diesel oil fraction hydrogenation upgrading technology, such as CN1156752A and CN1289832A, is a hydrogenation process technology using a hydrofining catalyst and a Y-type molecular sieve hydrogenation upgrading catalyst. Such techniques can increase the cetane number of diesel products by more than 10 units, but the pour point of the diesel does not change much.

Diesel oil fraction hydroisomerization pour point reducing technology, such as CN1718683A and CN1712499A, uses hydrofining catalyst and beta-zeolite-containing hydroisomerization pour point reducing catalyst, and adopts a one-stage series process to produce diesel oil product, but under the same hydro-upgrading condition, its cetane number is lower than that of hydro-upgraded diesel oil, and its technological condition is more strict than that of hydro-pour point diesel oil product.

Diesel oil fraction hydrogenation pour point depression technology, such as CN102051232A and CN1257107A, uses hydrofining catalyst and hydrogenation pour point depression catalyst, adopts a series flow to produce low pour point diesel oil product, but the yield of the diesel oil product is lower. CN102453531A, CN103805258A, CN103805254A and the like all use hydrofining catalysts and hydrodewaxing catalysts alternately, the condensation point of the obtained diesel oil product is low, but the yield of the diesel oil is low, and only one diesel oil product can be produced.

By adopting the hydrogenation technology CN105087063A, after diesel fraction is subjected to hydroisomerization and pour point depression, the diesel fraction is directly subjected to hydrogenation and pour point depression by utilizing reaction heat to produce a low-pour-point diesel product, but the process can only produce a diesel product with a pour point specification.

In conclusion, the existing diesel oil hydro-upgrading technology can obtain higher diesel oil product yield, greatly improve the product quality such as cetane number, sulfur content, aromatic hydrocarbon content, density and the like, but the condensation point reduction amplitude is not large or reduced, and the requirement of low condensation point diesel oil cannot be met. The existing hydroisomerization pour point depressing technology can greatly lower the pour point of a diesel product, can meet the index requirement of low pour point diesel, but has lower yield when producing the low pour point diesel product. The existing hydrogenation pour point depressing technology can greatly lower the pour point of a diesel product and can meet the index requirement of low-pour-point diesel, but the diesel yield is lower and is usually less than 90m%, the quality improvement range of the diesel product is not large, and the cetane number of the diesel product is reduced particularly when normal paraffin with high cetane number is cracked into gas or naphtha fraction. The product is single when the coupling hydrogenation technology is adopted. The diesel oil produced by the process technology is only one, and the product flexibility is poor.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a hydrogenation process for flexibly producing low-freezing point diesel, namely, a part of reactant flow is extracted from the middle part of a hydro-upgrading pour point depressing reactor, and the raw diesel oil is subjected to hydro-upgrading, hydro-isomerization pour point depressing and hydro-pour point depressing coupling methods to flexibly produce hydro-isomerization pour point depressing diesel products and hydro-pour point depressing diesel products with different freezing points.

The invention relates to a hydrogenation process for flexibly producing low-condensation-point diesel oil, which comprises the following steps:

a. firstly, passing diesel raw oil through a hydrofining catalyst bed under the hydrofining condition to obtain a hydrofining material flow;

b. b, passing the hydrofining material flow obtained in the step a through a hydro-upgrading catalyst bed under the hydro-upgrading condition to obtain a hydro-upgrading material flow, dividing the part of the reactant flow into two parts, and pumping one part of the reactant flow out of a hydro-upgrading reactor;

c. b, allowing the residual hydrogenation modified material flow in the step b to pass through a hydrogenation isomerization pour point depressing catalyst bed layer under the hydrogenation isomerization pour point depressing condition, and separating and fractionating the hydrogenation isomerization pour point depressing material flow to obtain hydrogenation isomerization pour point depressing high-pressure hydrogen-rich gas, hydrogenation isomerization pour point depressing gas products, hydrogenation isomerization pour point depressing naphtha products and hydrogenation isomerization pour point depressing diesel products;

d. and c, passing the extracted hydrogenation modified material flow obtained in the step b through a hydrogenation pour point depression catalyst bed layer of a hydrogenation pour point depression reactor under the hydrogenation pour point depression condition, and separating and fractionating the hydrogenation pour point depression material flow to obtain hydrogenation pour point depression high-pressure hydrogen-rich gas, hydrogenation pour point depression naphtha and hydrogenation pour point depression diesel products.

The hydrogenation process according to the invention may further comprise step e: and d, mixing the hydroisomerization pour point depressing high-pressure hydrogen-rich gas obtained in the step c with the hydrogenation pour point depressing high-pressure hydrogen-rich gas obtained in the step d for recycling.

In the invention, the hydrofining catalyst bed, the hydrogenation modified catalyst bed and the hydroisomerization pour point depression catalyst bed can be arranged in one reactor, for example, three catalyst beds can be respectively arranged in one hydrogenation reactor; or the hydrofining catalyst bed layer is arranged in a single hydrofining reactor, and the hydro-upgrading catalyst bed layer and the hydroisomerization pour point depression catalyst bed layer are arranged in one hydrogenation reactor; or the hydrofining catalyst bed layer, the hydro-upgrading catalyst and the hydroisomerization pour point depression catalyst bed layer are respectively arranged in the three hydrogenation reactors. The hydrodewaxing catalyst bed is usually arranged in a hydrodewaxing reactor separately.

S, N, O and other impurities in the raw diesel oil are effectively removed through a hydrofining catalyst, aromatic hydrocarbon is subjected to hydrogenation saturation to a certain extent, partial ring opening reaction of cyclic hydrocarbon occurs when hydrofining material flow continuously passes through a hydrofining catalyst bed layer, a component with a low cetane number is changed into a component with a high cetane number, and a part of hydrofining material flow is continuously subjected to hydroisomerization pour point depressing, so that the cetane number of the diesel oil is improved to the maximum extent, and a diesel oil product with a relatively high pour point and a high cetane number is obtained; and (3) reducing the condensation point of diesel after a part of the extracted hydro-upgrading material flow passes through a hydro-dewaxing catalyst to obtain a diesel product with a slightly lower cetane number and a very low condensation point.

Compared with the prior art, the hydrogenation process for flexibly producing the low-condensation-point diesel oil has the advantages that:

1. in the invention, the hydro-upgrading pour point depressing reactor comprises at least one hydro-upgrading catalyst bed layer and at least one hydroisomerization pour point depressing catalyst bed layer. Through the step of extracting the hydrogenation modified material arranged in the middle of the bed layer of the hydroisomerization pour point depressing reactor, the effective distribution of the hydrogenation modified material strand can be realized without special operation, and the obtained material is subjected to different hydrogenation processes, so that the target diesel oil products with different condensation points can be flexibly 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, a set of hydrogenation devices can only obtain diesel products with one specification; if diesel oil products with different specifications are required, more than two sets of hydrogenation devices are required. Therefore, the invention provides a hydro-conversion process for producing more than two diesel oil products with different specifications on one set of hydrogenation process device for the first time.

2. According to the invention, the hydro-upgrading material flow extracting device is arranged between the hydro-upgrading catalyst and the hydroisomerization pour point depressing catalyst bed layer of the hydro-upgrading pour point depressing reactor, the material flow of the diesel raw material after hydro-refining and hydro-upgrading is extracted out of the reactor and is respectively sent into the hydro-pour point depressing catalyst bed layers (reactors) which are independently arranged for hydro-pour point depressing reaction, and the pour point of the hydro-upgraded material is further reduced, so that the diesel products with different pour points and different cetane numbers can be flexibly produced by the method.

3. In the invention, the diesel oil product obtained after hydrogenation modification and hydroisomerization pour point depression has high cetane number and slightly higher pour point; the diesel oil product obtained after partial hydrogenation modification and hydrogenation pour point depression has low pour point and relatively low cetane number; can respectively meet the requirements of producing high-quality diesel products with different specifications.

4. In the invention, the liquid obtained between the modified catalyst bed layer of the hydrogenation modified pour point depressing reactor and the heterogeneous pour point depressing catalyst bed layer has very high temperature and pressure, and can directly enter the newly arranged hydrogenation pour point depressing reactor for reaction, thereby fully utilizing the heat carried by the modified material and realizing the coupling operation of the hydrogenation pour point depressing reactor and the hydrogenation heterogeneous pour point depressing reactor.

Drawings

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

Wherein: 1-raw oil, 2-hydrofining reactor, 3-hydrofining material flow, 4-hydrogenation modified pour point depression reactor, 5-hydrogenation pour point depression raw material flow, 6-hydrogenation isomerization pour point depression material flow, 7-hydrogenation pour point depression reactor, 8-hydrogenation isomerization pour point depression high-pressure separator, 9-hydrogenation pour point depression high-pressure separator, 10-hydrogenation isomerization pour point depression fractionating tower, 11-hydrogenation pour point depression fractionating tower, 12-hydrogenation isomerization pour point depression gas product, 13-hydrogenation isomerization pour point depression naphtha product, 14-hydrogenation isomerization pour point depression diesel oil product, 15-hydrogenation pour point depression gas product, 16-hydrogenation pour point depression naphtha product, 7-hydrogenation pour point depression diesel oil product, 18-hydrogenation isomerization pour point depression high-pressure separator gas product, 19-hydrogenation pour point depression high-pressure separator gas product, 20-make up hydrogen.

Detailed Description

The initial boiling point of the diesel raw material in the step a is 100-260 ℃, and the final boiling point is 300-450 ℃. The diesel raw oil can be one of straight-run diesel oil, coking diesel oil, catalytic diesel oil, hydrotreated diesel oil and the like obtained by petroleum processing, one of coal tar, coal direct liquefaction oil, coal indirect liquefaction 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 and the shale oil.

The hydrofining catalyst in the step a is a conventional diesel hydrofining catalyst. Generally, VIB group and/or VIII group metals are used as active components, and alumina or silicon-containing alumina is used as a carrier; the group VIB metal is typically Mo and/or W and the group VIII metal is typically 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 available commercial catalysts comprise hydrofining catalysts such as FH-5, FH-98, 3936, 3996, FUDS series and the like developed by the petrochemical research institute, and can also be similar catalysts with functions developed by 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 operation conditions can adopt the conventional operation conditions, generally the reaction pressure is 3.0MPa to 15.0MPa, the reaction temperature is 300 ℃ to 430 ℃, 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 hydro-upgrading catalyst in the step B is a conventional diesel hydro-upgrading catalyst, generally, metals in a VIB group and/or a VIII group are used as active components, 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. The carrier of the catalyst contains one or more of alumina, siliceous alumina and molecular sieve, preferably contains molecular sieve; the molecular sieve can be a Y-type molecular sieve. Based on the weight of the catalyst, VIThe content of B group metal is 10-35 wt% calculated by oxide, the content of VIII group metal is 3-15 wt% calculated by oxide, the content of molecular sieve is 5-40 wt%, and the content of alumina is 10-80 wt%; its specific surface area is 100m²/g～650m²The pore volume is 0.15mL/g to 0.50 mL/g. The main catalysts comprise 3963, FC-18, FC-32 catalysts and the like which are developed by the petrochemical research institute. For the hydrogenation modification catalyst, certain hydrogenation activity and certain cracking activity are required, and both hydrogenation saturation of olefin and aromatic hydrocarbon in diesel oil fraction and ring-opening reaction of saturated aromatic hydrocarbon are required. The operating conditions for the hydro-upgrading can be conventional and are generally: the reaction pressure is 3.0MPa to 15.0MPa, the reaction temperature is 300 ℃ to 430 ℃, and the liquid hourly volume space velocity is 0.3h^-1～15.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

The hydroisomerization pour point depressing catalyst in the step c is a conventional diesel hydroisomerization pour point depressing catalyst, generally, metals in a VIB group and/or a VIII group are used as active components, 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. The carrier of the catalyst contains one or more of alumina, silicon-containing alumina and molecular sieve, preferably contains molecular sieve, and the molecular sieve can be beta type molecular sieve, Sapo type molecular sieve and the like. 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, the content of the molecular sieve is 5-40 wt%, and the content of the alumina is 10-80 wt%; the specific surface area is 100m²/g～650m²The pore volume is 0.15mL/g to 0.50 mL/g. The main catalysts comprise FC-14, FC-20 and the like developed by the petrochemical research institute. For the hydrogenation modification catalyst, certain hydrogenation activity and certain cracking activity are required, and both the hydrogenation saturation of olefin and aromatic hydrocarbon in diesel oil fraction and the isomerization reaction of straight-chain paraffin are required. The hydroisomerization pour point depression may be carried out under conventional operating conditions, typically: the reaction pressure is 3.0MPa to 15.0MPa, the reaction temperature is 300 ℃ to 430 ℃, and the liquid hourly space velocity is 0.3h^-1～15.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

And c, in the step b, the mass proportion of the extracted partial material flow in the liquid phase to the raw oil is 5-95 wt%, and preferably 10-80 wt%.

The separation described in step c generally comprises separation of two parts, a hydroisomerization pour point depression high pressure separator and a low pressure separator. Wherein the high-pressure separator separates to obtain the hydroisomerization pour point depression high-pressure hydrogen-rich gas and liquid, 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. Separating the hydrocarbon-rich gas to obtain the required hydroisomerization pour point depression gas product.

The fractionation described in step c is carried out in a hydroisomerized pour point depressant fractionation column system. And fractionating the low-pressure liquid product in a fractionating tower to obtain a hydroisomerization pour point depressing naphtha product and a hydroisomerization pour point depressing diesel product.

The hydrogenation pour point depression catalyst in the step d is a conventional hydrogenation pour point depression catalyst, generally, metals in a VIB group and/or a VIII group are used as active components, 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. The carrier of the catalyst contains one or more of alumina, siliceous alumina and molecular sieve, preferably molecular sieve, which may be ZSM-5, ZSM-11, ZSM-22, ZSM-35 type molecular sieve, preferably ZSM-5 molecular sieve. Based on the weight of the catalyst, the total metal content is 1wt% -20 wt% calculated by oxide, the molecular sieve content is 40wt% -85 wt%, and the adhesive content is 10wt% -40 wt%. The main catalysts comprise 3881 and FDW-1 catalysts which are developed by the petrochemical research institute. The hydrodewaxing conditions may be conventional, and are generally: the reaction pressure is 3.0MPa to 15.0MPa, the reaction temperature is 300 ℃ to 440 ℃, and the liquid hourly space velocity is 0.3h^-1～12.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-1500: 1.

The separation in step d is carried out in a hydrodewaxing high pressure separator and a low pressure separator. The hydrogenation pour point depression high-pressure separator separates to obtain hydrogenation pour point depression high-pressure hydrogen-rich gas and liquid, 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. Separating the hydrocarbon-rich gas to obtain the required hydrogenation pour point depression gas product.

The fractionation in step d is carried out in a fractionating column system. And fractionating the low-pressure liquid product in a fractionating tower to obtain a hydrogenated pour point depressing naphtha product and a hydrogenated pour point depressing diesel product.

The hydroisomerization pour point depressing gas product and the hydrogenation pour point depressing gas product in the step c and the step d can be used as products independently or can be mixed into a mixed gas product.

The hydroisomerized pour point depressing naphtha product and the hydroisomerized pour point depressing naphtha product in the step c and the step d can be used as the products independently or can be mixed into a mixed naphtha product.

And e, mixing the high-pressure hydrogen-rich gas in the step e, and then directly using the mixed gas as recycle hydrogen, or recycling the mixed gas after hydrogen sulfide is removed by a recycle hydrogen desulfurization system.

With reference to fig. 1, the method of the present invention is as follows: raw oil 1 is firstly mixed with recycle hydrogen and enters a hydrofining reactor 2, a hydrofining material flow 3 enters a hydrofining pour point depressing reactor 4, a hydro-pour point depressing raw material flow 5 is extracted from a reaction material flow passing through a hydro-modifying catalyst bed layer, the material flow after the hydro-pour point depressing raw material flow 5 is extracted continues to enter a subsequent hydro-isomerizing pour point depressing catalyst bed layer, a hydro-isomerizing pour point depressing generated material flow 6 enters a hydro-isomerizing pour point depressing high-pressure separator 8 for gas-liquid separation, the separated liquid enters a fractionating tower 10 for fractionation to obtain a hydro-isomerizing pour point depressing gas product 12, a hydro-isomerizing pour point depressing naphtha product 13 and a hydro-isomerizing pour point depressing diesel oil product 14, the hydro-pour point depressing raw material flow 5 enters a hydro-pour point depressing reactor 7, the generated material flow passing through the hydro-pour point depressing catalyst bed layer enters a hydro-solidifying point depressing high-pressure separator 9 for gas-liquid separation, a hydrogenation pour point depression naphtha product 16 and a hydrogenation pour point depression diesel product 17, a hydrogenation isomerization pour point depression gas product 12 and a hydrogenation pour point depression gas product 15 can be used as products independently or can be mixed to obtain a mixed gas product, a hydrogenation isomerization pour point depression naphtha product 13 and a hydrogenation pour point depression naphtha product 16 can be used as products independently or can be mixed to obtain a mixed naphtha product, a gas 18 obtained by separating through a hydrogenation isomerization pour point depression high-pressure separator 8 and a gas 19 obtained by separating through a hydrogenation pour point depression high-pressure separator 9 are mixed and then are mixed with a make-up hydrogen 20 through a recycle hydrogen compressor to be used as recycle hydrogen.

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

Examples 1 to 3

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 FHUDS-5 is a hydrofining catalyst developed and produced by the smoothing petrochemical research institute of China petrochemical industry Limited company; the catalyst 3963 is a hydro-upgrading catalyst developed and produced by the research institute of the smooth petrochemical industry of the limited petrochemical company in China, and contains a Y-type molecular sieve; the catalyst FC-20 is a hydrogenation pour point depression catalyst developed and produced by China petrochemical company Limited, compliant petrochemical research institute, and contains a beta-type molecular sieve; the catalyst 3881 is a hydrogenation pour point depressing catalyst which is developed and produced by China petrochemical company Limited and comforts petrochemical research institute and contains ZSM-5 type molecular sieve.

TABLE 1 Main Properties of Diesel feed stock

Table 2 examples process conditions and test results

Table 2 example process conditions and test results

It can be seen from the examples that, by adopting the hydrogenation process of the invention, the aim of producing diesel oil with different properties is achieved by extracting a part of reactant flow from the hydro-upgrading isomerization pour point depressing reactor and using the hydro-isomerization pour point depressing catalyst and the hydro-pour point depressing catalyst, and the production mode is flexible.

Claims

1. A hydrogenation process for flexibly producing low-condensation-point diesel oil comprises the following steps:

b. b, passing the hydrofining material flow obtained in the step a through a hydro-upgrading catalyst bed under the hydro-upgrading condition to obtain a hydro-upgrading material flow, dividing the part of the reactant material flow into two parts, and extracting one part of the reactant material flow out of a hydrogenation reactor;

c. b, allowing the rest part of the hydrogenated modified material flow in the step b to pass through a hydroisomerization pour point depressing catalyst bed layer under a hydroisomerization pour point depressing condition, and separating and fractionating the hydroisomerization pour point depressing material flow to obtain a hydroisomerization pour point depressing high-pressure hydrogen-rich gas, a hydroisomerization pour point depressing gas product, a hydroisomerization pour point depressing naphtha product and a hydroisomerization pour point depressing diesel product;

2. The hydrogenation process of claim 1, further comprising step e: and d, mixing the hydroisomerization pour point depressing high-pressure hydrogen-rich gas obtained in the step c with the hydrogenation pour point depressing high-pressure hydrogen-rich gas obtained in the step d for recycling.

3. The hydrogenation process according to claim 1, wherein the diesel feedstock has an initial boiling point of 100 to 260 ℃ and an end point of 300 to 450 ℃.

4. The hydrogenation process according to claim 3, wherein the diesel feedstock is selected from one or more of straight-run diesel, coker diesel, catalytic diesel, hydrotreated diesel, coal tar, direct coal liquefaction oil, indirect coal liquefaction oil and shale oil.

5. The hydrogenation process according to claim 1, wherein the hydrofining catalyst in step a takes VIB group and/or VIII group metals as active components, and takes alumina or siliceous alumina as a 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.

6. The hydrogenation process according to claim 1, wherein the operating conditions of step a are: the reaction pressure is 3.0MPa to 15.0MPa, the reaction temperature is 300 ℃ to 430 ℃, 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.

7. The hydrogenation process according to claim 1, wherein the hydro-upgrading catalyst uses a group VIB and/or group VIII metal as an active component, and a carrier of the catalyst contains alumina and a molecular sieve; 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, the content of the molecular sieve is 5-40 wt%, and the content of the alumina is 10-80 wt%; the specific surface area is 100m²/g～650m²The pore volume is 0.15mL/g to 0.50 mL/g.

8. The hydrogenation process of claim 1, wherein the hydro-upgrading conditions are: the reaction pressure is 3.0MPa to 15.0MPa, the reaction temperature is 300 ℃ to 430 ℃, and the liquid hourly volume space velocity is 0.3h^-1～15.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

9. The hydrogenation process of claim 1, wherein the hydrogenation of step cThe heterogeneous pour point depressing catalyst takes VIB group and/or VIII group metal as an active component, and a catalyst carrier contains alumina and a molecular sieve; 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, the content of the molecular sieve is 5-40 wt%, and the content of the alumina is 10-80 wt%; the specific surface area is 100m²/g～650m²The pore volume is 0.15mL/g to 0.50 mL/g.

10. The hydrogenation process of claim 1, wherein the hydroisomerization pour point depression is performed under the following operating conditions: the reaction pressure is 3.0MPa to 15.0MPa, the reaction temperature is 300 ℃ to 430 ℃, and the liquid hourly space velocity is 0.3h^-1～15.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

11. The hydrogenation process according to claim 1, wherein the hydrogenation pour point depressing catalyst is a catalyst with metals of VIB group and/or VIII group as active components, the carrier of the catalyst contains alumina and a molecular sieve, the molecular sieve is a ZSM-5, ZSM-11, ZSM-22 or ZSM-35 type molecular sieve, and based on the weight of the catalyst, the total metal content is 1wt% -20 wt% calculated by oxide, the molecular sieve content is 40wt% -85 wt%, and the alumina content is 10wt% -40 wt%.

12. The hydrogenation process of claim 1, wherein the hydrodewaxing operating conditions are: the reaction pressure is 3.0MPa to 15.0MPa, the reaction temperature is 300 ℃ to 440 ℃, and the liquid hourly space velocity is 0.3h^-1～12.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-1500: 1.

13. The hydrogenation process according to claim 1, wherein the partial stream extracted in step b accounts for 5-95 wt% of the raw oil in terms of liquid phase.

14. The hydrogenation process according to claim 1, wherein the partial stream extracted in step b accounts for 10-80 wt% of the raw oil in terms of liquid phase.

15. The hydrogenation process according to claim 1, wherein the hydrofinishing catalyst bed, the hydro-upgrading catalyst bed and the hydroisomerization pour point depression catalyst bed are arranged in a reactor; or the hydrofining catalyst bed layer is arranged in a single hydrofining reactor, and the hydro-upgrading catalyst bed layer and the hydroisomerization pour point depression catalyst bed layer are arranged in one hydrogenation reactor; or the hydrofining catalyst bed layer, the hydro-upgrading catalyst and the hydroisomerization pour point depression catalyst bed layer are respectively arranged in the three hydrogenation reactors.