CN109988622B

CN109988622B - Flexible diesel hydro-upgrading pour point depressing process

Info

Publication number: CN109988622B
Application number: CN201711469562.0A
Authority: CN
Inventors: 刘涛; 方向晨; 李宝忠; 赵玉琢; 李扬; 孙洪江
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: CN109988622A

Abstract

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

Description

Flexible diesel hydro-upgrading pour point depressing process

Technical Field

The invention belongs to the field of petroleum refining, and particularly relates to a diesel hydro-upgrading pour point depressing process for flexibly producing high-quality diesel products.

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 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.

A combined hydrogenation technology CN1415705A is adopted as a production method of high-quality diesel oil, raw oil is subjected to hydrorefining and hydrodewaxing and then subjected to gas-liquid separation, and a liquid product is subjected to hydrogenation dearomatization by using a noble metal catalyst.

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 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 combined hydrogenation technology has complex flow and single product. 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 flexible diesel hydro-upgrading pour point depressing process, namely, a part of reactant flow is extracted from the middle part of a hydro-upgrading reactor, and the diesel raw oil is flexibly produced into high-quality hydro-upgrading diesel products and high-quality hydro-upgrading pour point depressing diesel products by a hydro-upgrading and hydro-depressing combined method.

The invention relates to a flexible diesel hydro-upgrading pour point depressing process method, 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. under the condition of hydrogenation modification, passing the hydrofining material flow obtained in the step a through a first hydrogenation modification catalyst bed layer of a hydrogenation modification reactor to obtain a first hydrogenation modification material flow, dividing the part of the reaction material flow into two parts, and extracting one part of the reaction material flow out of the hydrogenation reactor;

c. under the condition of hydro-upgrading, continuously passing the rest part of the first hydro-upgrading material flow in the step b through a second hydro-upgrading catalyst bed layer of the hydro-upgrading reactor, and separating and fractionating the second hydro-upgrading material flow to obtain a hydro-upgrading high-pressure hydrogen-rich gas, a hydro-upgrading gas product, a hydro-upgrading naphtha product and a hydro-upgrading diesel product;

d. and (c) under the condition of hydrogenation pour point depression, the first hydrogenation modified material flow obtained in the step (b) passes through a hydrogenation pour point depression catalyst bed layer of a hydrogenation pour point depression reactor, and the hydrogenation pour point depression material flow is separated and fractionated to obtain hydrogenation pour point depression high-pressure hydrogen-rich gas, hydrogenation pour point depression naphtha and hydrogenation pour point depression diesel oil products.

The hydro-upgrading pour point depressing process according to the invention can further comprise the following steps of e: and d, mixing the hydro-upgrading high-pressure hydrogen-rich gas obtained in the step c with the hydro-pour point depressing high-pressure hydrogen-rich gas obtained in the step d for recycling.

In the invention, the hydrofining catalyst bed, the first hydro-upgrading catalyst bed and the second hydro-upgrading catalyst bed can be arranged in one hydrogenation reactor, for example, three catalyst beds can be arranged in one hydro-upgrading reactor in sequence; or the hydrofining catalyst bed layer is arranged in a single hydrogenation reactor, and the first hydro-upgrading catalyst bed layer and the second hydro-upgrading catalyst bed layer are arranged in one hydro-upgrading reactor; or the hydrorefining catalyst bed layer and the first hydroupgrading catalyst bed layer are arranged in one hydroupgrading reactor, and the second hydroupgrading catalyst bed layer is arranged in the other hydroupgrading reactor.

S, N, O and other impurities in the raw diesel oil are effectively removed when passing through a hydrofining catalyst, and aromatic hydrocarbons are hydrogenated and saturated to a certain extent; when the hydrofining material flow continuously passes through the hydrogenation modification catalyst bed layer, the annular hydrocarbon is subjected to partial ring-opening reaction, the low-cetane component is changed into the high-cetane component, and one part of the hydrofining material flow is subjected to the hydrogenation modification reaction continuously, so that the cetane number of the diesel oil is improved to the maximum extent, and a diesel oil product with a relatively high condensation point and a high cetane number is obtained; and after part of the first hydrogenation upgrading material flow is extracted and passes through the hydrogenation pour point depressing catalyst, the condensation point of diesel oil is further reduced, and a diesel oil product with cetane number meeting the requirement but low condensation point is obtained.

Compared with the prior art, the flexible diesel hydro-upgrading pour point depressing process has the advantages that:

1. in the invention, the hydro-upgrading reaction part comprises at least two hydro-upgrading catalyst beds. Through the step of extracting the modified material arranged in the middle of the hydrogenation modified catalyst bed, 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 target diesel oil products with different specifications can be flexibly produced. At the same time, the withdrawal of the reactant stream in the middle of the catalyst bed is technically simple to achieve. 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 first hydrogenation modified material flow extracting device is arranged in the middle of the modified catalyst bed layer of the hydrogenation modified reactor, the first hydrogenation modified material flow obtained by hydrofining and hydrogenation modification of the diesel raw material is extracted out of the reactor and is respectively sent to the hydrogenation pour point depressing reactors which are independently arranged for hydrogenation pour point depressing reaction, so that the pour point of the hydrogenation modified material is further reduced, and therefore, the method disclosed by the invention can be used for flexibly producing diesel products with different pour points and different cetane numbers.

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

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

Drawings

Fig. 1 is a schematic flow chart of the principle of the present invention. Wherein a hydrofining reactor, a hydro-upgrading reactor and a hydro-pour point depressing reactor are arranged; the hydro-upgrading reactor comprises two hydro-upgrading catalyst beds.

Wherein: 1-raw oil, 2-hydrofining reactor, 3-hydrofining material flow, 4-hydroupgrading reactor, 5-hydrodewaxing raw material flow, 6-hydroupgrading material flow, 7-hydrodewaxing reactor, 8-hydroupgrading high-pressure separator, 9-hydrodewaxing high-pressure separator, 10-hydroupgrading fractionating tower, 11-hydrodewaxing fractionating tower, 12-hydroupgrading gas product, 13-hydroupgrading naphtha product, 14-hydroupgrading diesel product, 15-hydrodewaxing gas product, 16-hydrodewaxing naphtha product, 7-hydrodewaxing diesel product, 18-hydroupgrading high-pressure separator gas product, 19-hydrodewaxing high-pressure separator gas product and 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. The hydrofining catalyst uses VIB group and/or VIII group metal as active component, uses alumina or silicon-containing alumina as carrier, and uses the VIB group metal as Mo and/or W, and uses the VIII group metal as 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 hydrofining catalysts such as FH-5, FH-98, 3936 and 3996, FHUDS 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 of the hydrogenation refining in the step a can adopt the conventional operation conditions, such as hydrogen partial pressure of 3.0MPa to 15.0MPa, reaction temperature of 300 ℃ to 430 ℃, liquid hourly space velocity of 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 steps B and c 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 is one or more of alumina, siliceous alumina and molecular sieve, preferably containing molecular sieve. The molecular sieve can be a Y-type molecular sieve. Based on the weight of the catalyst, the content of the VIB group metal is 10 to 35 weight percent calculated by oxide, the content of the VIII group metal is 3 to 15 weight percent calculated by oxide, the content of the molecular sieve is 5 to 40 weight percent, the content of the alumina is 10 to 80 weight percent, and the 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, both the hydrogenation saturation of olefin and aromatic hydrocarbon in diesel oil fraction is ensured, and the ring opening of saturated aromatic hydrocarbon is also requiredAnd (4) reacting. 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.

According to a preferred embodiment of the present invention, the catalyst used in the first hydrogenation upgrading catalyst bed is hydrogenation catalyst a, and the catalyst used in the second hydrogenation upgrading catalyst bed is hydrogenation catalyst B. The content percentage x of the molecular sieve in the hydrogenation catalyst A₁Less than the percentage content x of the molecular sieve in the hydrogenation catalyst B₂Preferably x₁Ratio x₂1-6 percentage points lower, more preferably x₁Ratio x₂2-5 percentage points lower. According to the preferred embodiment, the hydro-upgrading reaction can achieve a better ring-opening effect, thereby contributing to further improvement in the cetane number of the resulting product. The reason is that after the raw oil passes through the first hydrogenation modified catalyst bed layer, one part of polycyclic aromatic hydrocarbon is subjected to hydrofining saturation and modification reaction, and then one ring at the outermost layer is subjected to ring opening reaction, so that the volume of the hydrocarbon molecules subjected to ring opening is increased, the steric hindrance is increased, and the difficulty of continuing the modification reaction is correspondingly increased, therefore, the content of the molecular sieve in the second hydrogenation modified catalyst (namely, the catalyst B) is properly increased to improve the reaction activity of the catalyst, the subsequent ring opening reaction of the second ring can be better completed, and the cetane number of the obtained diesel oil can be increased.

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 typically comprises a hydro-upgrading high pressure separator and a low pressure separator separating the two parts. Wherein the high-pressure separator separates to obtain hydro-upgrading 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 modified gas product.

The fractionation described in step c is carried out in a hydro-upgrading fractionator system. And fractionating the low-pressure liquid product in a fractionating tower to obtain a hydrogenation modified naphtha product and a hydrogenation modified 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 catalyst has carrier of one or more of alumina, silica-containing alumina and molecular sieve, preferably containing molecular sieve, which may be ZSM-5, ZSM-11, ZSM-22 or 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: hydrogen partial pressure is 3.0MPa to 15.0MPa, reaction temperature is 300 ℃ to 440 ℃, and liquid hourly volume 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.

And d, performing fractionation in a fractionating tower system, and fractionating the low-pressure liquid product in the fractionating tower to obtain a hydrodewaxing naphtha product and a hydrodewaxing diesel oil product.

The hydro-upgrading gas product and the hydro-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 hydro-upgrading naphtha product and the hydro-dewaxing naphtha product in the step c and the step d can be used as 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 hydro-upgrading reactor 4, a hydro-dewaxing material flow 5 is extracted from a reactant flow passing through a first hydro-upgrading catalyst bed, the material flow after the hydro-dewaxing material flow 5 is extracted continues to enter a subsequent second hydro-upgrading catalyst bed, a hydro-upgrading product flow 6 enters a hydro-upgrading high-pressure separator 8 for gas-liquid separation, the separated liquid enters a fractionating tower 10 for fractionation to obtain a hydro-upgrading gas product 12, a hydro-upgrading naphtha product 13 and a hydro-upgrading diesel product 14, the hydro-dewaxing material flow 5 enters a hydro-dewaxing reactor 7, the product flow passing through the hydro-dewaxing catalyst bed enters a hydro-dewaxing high-pressure separator 9 for gas-liquid separation, the separated liquid enters a fractionating tower 11 for fractionation to obtain a hydro-dewaxing gas product 15, A hydrogenation pour point depression naphtha product 16 and a hydrogenation pour point depression diesel product 17, a hydrogenation modified gas product 12 and a hydrogenation pour point depression gas product 15 can be used as products independently or mixed to obtain a mixed gas product, a hydrogenation modified naphtha product 13 and a hydrogenation pour point depression naphtha product 16 can be used as products independently or mixed to obtain a mixed naphtha product, and a gas 18 obtained by separation in a hydrogenation modified high-pressure separator 8 and a gas 19 obtained by separation in a hydrogenation pour point depression high-pressure separator 9 are mixed and then mixed with make-up hydrogen 20 to be used as recycle hydrogen after passing through a recycle hydrogen compressor.

The technical solution and effects of the present invention will be described below by way of specific 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 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 content of the Y-type molecular sieve in the 3963B catalyst is 4 percent (number) higher than that of the Y-type molecular sieve in the 3963 catalyst, and the rest is unchanged; 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 3 example process conditions and test results

It can be seen from the examples that, by adopting the hydro-upgrading process of the present invention, the purpose of producing diesel oil with different properties is realized by extracting a part of reactant flow from the hydro-upgrading reactor and using the hydro-upgrading catalyst and the hydro-pour point depressing catalyst, and the production mode is flexible. And the hydrogenation modification part is graded by using two modification catalysts with different molecular sieve contents, so that the cetane number of the obtained modified diesel oil can be increased, and the production flexibility of the method is improved.

Claims

1. A flexible diesel hydro-upgrading pour point depressing process comprises the following steps:

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

3. The hydro-upgrading pour point depressing process according to claim 1, wherein the initial boiling point of the diesel raw oil is 100 to 260 ℃ and the final boiling point is 300 to 450 ℃.

4. The hydro-upgrading pour point depressing process according to claim 3, characterized in that the diesel raw oil is one or more selected from the group consisting 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 hydro-upgrading pour point depressing 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; group VIB metal content by weight of catalyst10-35 wt% of the compound, and 3-15 wt% of the VIII family metal 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 hydro-upgrading pour point depressing process according to claim 1, wherein the operating conditions of step a are: the hydrogen partial 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 hydro-upgrading pour point depressing process according to claim 1, wherein the hydro-upgrading catalyst in the steps B and c takes metals in the VIB group and/or the VIII group as active components, and the carrier of the catalyst is one or more of alumina, siliceous alumina and molecular sieve.

8. The hydro-upgrading pour point depressing process according to claim 7, wherein the carrier of the hydro-upgrading catalyst is alumina and molecular sieve; based on the weight of the catalyst, the content of the VIB group metal is 10 to 35 weight percent calculated by oxide, the content of the VIII group metal is 3 to 15 weight percent calculated by oxide, the content of the molecular sieve is 5 to 40 weight percent, the content of the alumina is 10 to 80 weight percent, and the specific surface area is 100m²/g～650m²The pore volume is 0.15mL/g to 0.50 mL/g.

9. The hydro-upgrading pour point depressing process according to claim 8, wherein the catalyst used in the first hydro-upgrading catalyst bed is hydrogenation catalyst A, the catalyst used in the second hydro-upgrading catalyst bed is hydrogenation catalyst B, and the content percentage x of the molecular sieve in the hydrogenation catalyst A is₁Less than the percentage content x of the molecular sieve in the hydrogenation catalyst B₂。

10. The hydro-upgrading pour point depressing process of claim 9, wherein x is₁Ratio x₂1-6 percentage points lower.

11. The hydro-upgrading pour point depressing process according to claim 1, wherein the hydro-upgrading conditions are: hydrogen partial pressure is 3.0MPa to 15.0MPa, reaction temperature is 300 ℃ to 430 ℃, and 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.

12. The hydro-upgrading pour point depressing process according to claim 1, wherein the partial material flow extracted in the step b accounts for 5-95 wt% of the raw material oil in terms of liquid phase.

13. The hydro-upgrading pour point depressing process according to claim 1, wherein the partial material flow extracted in the step b accounts for 10-80 wt% of the raw material oil in terms of liquid phase.

14. The hydro-upgrading pour point depressing process according to claim 1, wherein the hydro-pour point depressing catalyst takes metals in a VIB group and/or a VIII group as active components, the carrier of the catalyst is alumina and/or siliceous alumina and a molecular sieve, and the molecular sieve is a ZSM-5, ZSM-11, ZSM-22 or ZSM-35 type molecular sieve.

15. The process of claim 14, wherein the metal active component is present in an amount of 1wt% to 20wt% as oxide, the molecular sieve is present in an amount of 40wt% to 85wt%, and the binder is present in an amount of 10wt% to 40wt%, based on the weight of the hydrodewaxing catalyst.

16. The hydro-upgrading pour point depressing process according to claim 1, wherein the hydrorefining catalyst bed, the first hydro-upgrading catalyst bed and the second hydro-upgrading catalyst bed are arranged in a hydrogenation reactor; or the hydrofining catalyst bed layer is arranged in a single hydrogenation reactor, and the first hydro-upgrading catalyst bed layer and the second hydro-upgrading catalyst bed layer are arranged in one hydro-upgrading reactor; or the hydrorefining catalyst bed layer and the first hydroupgrading catalyst bed layer are arranged in one hydroupgrading reactor, and the second hydroupgrading catalyst bed layer is arranged in the other hydroupgrading reactor.

17. The hydro-upgrading pour point depressing process of claim 10, wherein x is₁Ratio x₂2-5 percentage points lower.