CN109988599B

CN109988599B - Flexible hydrogenation modification process for inferior diesel oil

Info

Publication number: CN109988599B
Application number: CN201811289680.8A
Authority: CN
Inventors: 刘涛; 赵玉琢; 李宝忠; 郭兵兵; 曾榕辉; 方向晨
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: 2018-10-31
Publication date: 2021-07-09
Anticipated expiration: 2038-10-31
Also published as: CN109988599A

Abstract

The invention discloses a flexible hydro-upgrading process for poor diesel oil. Feeding a diesel raw material into a hydrofining reactor, and dividing the material passing through an upper hydrofining catalyst bed into two parts; one material is pumped out of the refining reactor through the middle of the bed layer and enters a supplementary hydrorefining reactor for supplementary hydrogenation reaction; and the other strand of material continuously flows downwards through a hydrofining catalyst bed layer at the lower part, the hydrofining material continuously enters a hydro-upgrading reactor, and the obtained hydro-upgrading reaction material and the supplementary hydro-upgrading reaction material are subjected to gas-liquid separation and fractionation respectively to obtain a high-quality diesel oil product and a high-quality FCC feed. The invention provides a hydrogenation combined process for simultaneously producing more than two diesel fractions with different purposes on one set of hydrogenation process device for the first time, which can fully utilize the heat carried by part of refined materials to realize the coupling operation of a hydrofining reactor and a supplementary hydrofining reactor.

Description

Flexible hydrogenation modification process for inferior diesel oil

Technical Field

The invention belongs to the field of petroleum refining, and particularly relates to a flexible diesel oil hydro-upgrading process for flexibly producing high-quality diesel oil products and high-quality FCC (fluid catalytic cracking) raw materials by using inferior diesel oil as raw oil.

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. 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.

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. 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. CN101875856A, CN102465035A, CN106701189A, and CN106701190A disclose a process technology for blending LCO in wax oil hydrotreating or residual oil hydrotreating process, which mainly aims to produce high-quality catalytic cracking raw material, or a coupling technology for circulating LCO between a wax oil hydrotreating device and a catalytic cracking device, so as to realize clean production of the catalytic cracking device.

In conclusion, the existing diesel oil hydrogenation modification technology can obtain higher diesel oil product yield by using poor diesel oil fraction, the product quality is greatly improved, such as cetane number, sulfur content, aromatic hydrocarbon content, density and the like, or the condensation point of a diesel oil product is greatly reduced to meet the index requirement of low-condensation diesel oil, and the diesel oil obtained by hydrogenation modification is directly used as a product without producing FCC raw materials. In the existing LCO hydrogenation technology, LCO is usually directly blended into a diesel oil refining device, a wax oil hydrotreating device or a residual oil hydrotreating device for hydrogenation, hydrogenated diesel oil obtained after mixing hydrogenation is directly used as a diesel oil product, hydrogenated wax oil, hydrogenated residual oil and hydrogenated LCO are jointly used as raw materials of a catalytic cracking device, namely the LCO is hydrogenated and then returns to the catalytic cracking device, and the quality of catalytic cracking gasoline is not optimal because the hydrogenation depth of the LCO is not controlled deliberately and only the total sulfur and nitrogen content of a hydrotreating mixed material is controlled. And the diesel oil product 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 hydro-upgrading process for poor diesel, namely, a part of reactant flow is extracted from the middle part of a hydrofining reactor, and the poor diesel raw oil is subjected to hydro-upgrading and supplementary hydro-refining to flexibly produce high-quality hydro-upgraded diesel products and high-quality FCC raw materials.

The invention relates to a flexible hydro-upgrading process for poor diesel, which comprises the following steps:

a. firstly, passing the poor-quality diesel raw oil through a first hydrofining catalyst bed layer of a hydrofining reactor under the hydrofining condition to obtain a first hydrofining material flow, wherein the part of the reaction material flow is divided into two parts, and one part of the reaction material flow is pumped out of the hydrofining reactor;

b. b, continuously allowing the rest part of the first hydrofining material flow in the step a to pass through a second hydrofining catalyst bed layer of the hydrofining reactor under the hydrofining condition to obtain a hydrofining material flow;

c. b, allowing the hydrofined material flow obtained in the step b to enter a hydro-upgrading reactor, allowing the hydrofined material flow to pass through a hydro-upgrading catalyst bed under the hydro-upgrading condition, and separating and fractionating the hydro-upgraded 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 (b) passing the first hydrofined material flow extracted from the reactor in the step a through a supplementary hydrofined catalyst bed layer of the supplementary hydrofined reactor under the hydrofining condition after being independent or mixed with other poor-quality raw oil, and separating and fractionating the supplementary hydrofined material flow to obtain supplementary hydrofined high-pressure hydrogen-rich gas, supplementary hydrofined naphtha and supplementary hydrofined diesel.

The flexible hydro-upgrading process for poor diesel oil 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 supplementary hydro-refining high-pressure hydrogen-rich gas obtained in the step d for recycling.

The diesel oil hydrogenation upgrading process uses two types of catalysts, the hydrofining catalyst can effectively remove S, N, O and other impurities in the diesel oil raw oil, aromatic hydrocarbon is subjected to hydrogenation saturation to a certain extent, and the ring-opening reaction of cyclic hydrocarbon occurs when the hydrofining material flow continuously passes through a hydrogenation upgrading catalyst bed layer, or macromolecules are cracked into small molecules, so that the cetane number of a diesel oil product is effectively improved, the density is reduced, or the condensation point is reduced, and the quality of the diesel oil product is integrally improved. 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 a large 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, part of polycyclic aromatic hydrocarbon in extracted hydrofining material flow is already partially hydrogenated and saturated, the rest polycyclic aromatic hydrocarbon can be further hydrogenated and saturated by further supplementing a hydrofining catalyst, namely the hydrogenation depth of LCO can be just controlled by adjusting the volume space velocity and the reaction temperature, namely, the bicyclic aromatic hydrocarbon and the polycyclic aromatic hydrocarbon in LCO are hydrogenated to the monocyclic aromatic hydrocarbon on the premise of meeting the sulfur content, but not the hydrogenation depth generates cyclane excessively, or the hydrogenation depth is insufficient to generate the bicyclic aromatic hydrocarbon, so that the content of the aromatic hydrocarbon in the catalytic cracking gasoline can be increased when the hydrofined products enter a catalytic cracking device again, thereby improving the octane number of the catalytic cracking gasoline. For the two processes, the common part is that inferior diesel oil needs to be hydrofined, only the hydrofining depth is different, the hydro-upgrading not only needs to completely remove impurities such as sulfur, nitrogen and the like, but also needs to control the deep hydrogenation depth of aromatic hydrocarbon, and the LCO hydrogenation is mainly used for controlling the hydrogenation of the aromatic hydrocarbon to monocyclic aromatic hydrocarbon when being used as an FCC raw material.

Compared with the prior art, the flexible hydrogenation modification process of the inferior diesel has the advantages that:

1. in the invention, the hydrofining reactor comprises at least two hydrofining catalyst beds. The refined material extraction step arranged in the middle of the bed layer of the hydrofining reactor can realize effective distribution of hydrofining material strands without special operation, and the obtained material is subjected to different hydrogenation processes, so that high-quality diesel oil products and high-quality catalytic cracking raw materials 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 fraction products with different specification requirements on one set of hydrogenation process device at the same time for the first time.

2. According to the method, the first hydrofining material flow extracting device is arranged in the middle of the catalyst bed layer of the hydrofining reactor, the first hydrofining material flow obtained by partially hydrofining the diesel oil raw material is extracted out of the reactor and is sent into the independently arranged supplementary hydrofining reactor to carry out supplementary hydrogenation reaction, the degree of the supplementary hydrogenation reaction is controlled, and the depth of hydrogenation of aromatic hydrocarbon is controlled, so that the method can produce high-quality catalytic cracking raw materials.

3. In the invention, the diesel raw oil is subjected to deep hydrofining and hydro-upgrading to obtain a high-quality diesel product with high cetane number, low density or low condensation point and no impurities such as sulfur, nitrogen and the like.

4. In the invention, the material obtained in the middle of the hydrofining catalyst bed layer of the hydrofining reactor has very high temperature and pressure, and can directly enter a newly arranged supplementary hydrofining reactor for reaction, thereby fully utilizing the heat carried by the part of the refined material and realizing the coupling operation of the hydrofining reactor and the supplementary hydrofining reactor.

Drawings

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

Wherein: 1-raw oil 1, 2-hydrofining reactor, 3-hydrofining material flow, 4-hydrofining reactor, 5-extracted material flow, 6-hydrofining material flow, 7-supplementary hydrofining reactor, 8-hydrofining high-pressure separator, 9-supplementary hydrofining high-pressure separator, 10-hydrofining fractionating tower, 11-supplementary hydrofining fractionating tower, 12-hydrofining gas product, 13-hydrofining naphtha product, 14-hydrofining diesel product, 15-supplementary hydrofining gas product, 16-supplementary hydrofining naphtha product, 17-supplementary hydrofining diesel product, 18-hydro-upgrading high-pressure separator gas product, 19-supplementary hydrofining high-pressure separator gas product, 20-make-up hydrogen, 21-raw oil 2.

Detailed Description

The initial boiling point of the poor diesel raw material in the step a is 100-260 ℃, the final boiling point is 300-450 ℃, and the poor diesel raw material mainly has the characteristics of high density, high aromatic hydrocarbon content and the like. The poor quality diesel raw oil can be one of naphthenic base straight-run diesel oil, coking diesel oil, catalytic diesel oil, hydrotreating 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 naphthenic base straight-run diesel oil, the coking diesel oil, the catalytic diesel oil, the hydrotreating diesel oil and the like.

The hydrofining catalysts in the steps a, b and d are all conventional diesel hydrofining catalysts. 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 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 hydrofinishing catalysts described in step a, step b and step d may be the same or different. The operation conditions of the step a can adopt 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.

And c, taking the part of the extracted material flow in the step a as a liquid phase, wherein the part of the extracted material flow accounts for 5-95 wt% of the raw oil, and preferably 10-80 wt%.

The operation conditions of the step b 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 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, silicon-containing alumina and molecular sieve, preferably molecular sieveCan be Y-type molecular sieve, beta-type molecular sieve, Sapo-type molecular sieve, etc. 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, FC-14, FC-20 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 separation described in step c typically comprises separating two parts for a hydro-upgrading high pressure separator and a low pressure separator. 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 raw oil of the other poor diesel oil in the step d can be the same as or different from the poor diesel oil in the step a, and preferably, the distillate is lower than the diesel oil raw material with the poor diesel oil in the step a in dry point and the low polycyclic aromatic hydrocarbon content.

The operation conditions of the step d can adopt the conventional operation conditions, generally the total 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 separation described in step d is carried out in a supplemental hydrofinishing high pressure separator and a low pressure separator. The high-pressure separator is used for separating the hydrogen-rich gas and the liquid to obtain the hydrogen-rich gas, and the liquid obtained 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 supplementary hydrofining gas product.

And d, fractionating in the step d into a stripping tower or a fractionating tower system, and fractionating in a low-pressure liquid product stripping tower or a fractionating tower to obtain a supplemented hydrofined naphtha product and a supplemented hydrofined diesel product.

The hydro-upgrading gas product and the supplementary hydro-refining gas product in the steps c and d can be used as products independently or can be mixed into a mixed gas product.

The hydro-upgrading naphtha product and the supplementary hydrorefining naphtha product in the steps c and 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.

According to the invention, the inferior raw oil can be further divided into two parts according to the light fraction and the heavy fraction, wherein the division temperature point is 245-300 ℃, namely the fraction range of the light fraction is from the initial distillation point to the division point, and the fraction range of the heavy fraction is from the division point to the final distillation point. Therefore, another technical solution of the present invention includes:

a flexible hydro-upgrading method for poor diesel oil comprises the following steps:

a. cutting the poor-quality diesel raw oil into light fraction and heavy fraction; the heavy fraction firstly passes through a first hydrofining catalyst bed layer of a hydrofining reactor under the hydrofining condition to obtain a first hydrofining material flow, the part of the reaction material flow is divided into two parts, and one part of the reaction material flow is extracted from the hydrofining reactor;

b. b, allowing the rest part of the first hydrofining material flow in the step a to pass through a second hydrofining catalyst bed layer of a hydrofining reactor independently or together with part of the light fraction under the hydrofining condition to obtain a hydrofining material flow;

d. and b, mixing the first hydrofined material flow extracted in the step a with the light fraction, passing through a supplementary hydrofined catalyst bed of a supplementary hydrofined reactor under the hydrofining condition, and separating and fractionating the supplementary hydrofined material flow to obtain supplementary hydrofined high-pressure hydrogen-rich gas, supplementary hydrofined naphtha and supplementary hydrofined diesel.

In the technical scheme, the hydrofining catalyst and the hydrofining conditions are the same as those described above.

Wherein the weight percentage of the light fraction entering the supplementary hydrorefining reactor to the total light fraction obtained in the step a is 10-100%. The weight percentage of the light fraction entering the second hydrofining catalyst bed layer of the hydrofining reactor to the total light fraction is 0-90%.

In the present invention, the "first" and "second" are defined in the order of contact with the reaction raw materials. In the hydrofining reactor, firstly, the catalyst bed layer contacted with reaction raw material is "first" catalyst bed layer, and then the catalyst bed layer contacted with reaction raw material is "second" catalyst bed layer.

The heavy fraction mainly contains polycyclic aromatic hydrocarbon and can achieve the purpose of controlling the hydrogenation depth of the aromatic hydrocarbon through more hydrogenation refining catalyst reaction, and the light fraction contains double-ring aromatic hydrocarbon and can achieve the purpose of controlling the hydrogenation depth of the aromatic hydrocarbon simultaneously with the heavy fraction through less hydrogenation refining catalyst reaction, namely, the supplemented and hydrogenated diesel oil can meet the requirement of sulfur content, simultaneously properly hydrogenate the double-ring aromatic hydrocarbon and the polycyclic aromatic hydrocarbon to monocyclic aromatic hydrocarbon, and can meet the requirement of sulfur content after further catalytic cracking, and the octane number of the gasoline can be improved. Meanwhile, heavy fractions pass through more hydrofining catalysts, light fractions pass through less hydrofining catalysts, the hydrogenation depth of aromatic hydrocarbon can be further enhanced, the requirement of hydro-upgrading as much as possible is met, and high-quality hydro-upgraded diesel oil products with lower polycyclic aromatic hydrocarbon content can be produced.

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 supplementary hydrofining raw material flow 5 is extracted from a reactant flow passing through a first hydrofining catalyst bed, the first hydrofining material flow after the supplementary hydrofining raw material flow is extracted enters a subsequent hydrofining catalyst bed, a hydrofining product flow 3 enters a hydro-upgrading reactor 4, a hydro-upgrading product flow 6 of the hydro-upgrading catalyst bed enters a hydro-upgrading high-pressure separator 8 for gas-liquid separation, the liquid obtained by the separation 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 extracted supplementary hydrofining raw material flow 5 is mixed with a supplementary hydrofining raw material flow 21 and then enters a supplementary hydrofining reactor 7, and the product flow passing through the supplementary hydrofining catalyst bed enters a supplementary hydrofining high-pressure separator 9 for gas-liquid separation, the separated liquid enters a stripping tower 11 to obtain a supplementary hydrorefining gas product 15, a supplementary hydrorefining naphtha product 16 and supplementary hydrorefining diesel oil 17, the hydroupgrading gas product 12 and the supplementary hydrorefining gas product 15 can be used as products independently or mixed to obtain a mixed gas product, the hydroupgrading naphtha product 13 and the supplementary hydrorefining naphtha product 16 can be used as products independently or mixed to obtain a mixed naphtha product, and the gas 18 separated by the hydroupgrading high-pressure separator 8 and the gas 19 separated by the supplementary hydrorefining high-pressure separator 9 are mixed and then mixed with supplementary hydrogen 20 to serve as recycle hydrogen after passing through a recycle hydrogen compressor.

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 FHUDS-6 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.

TABLE 1 Main Properties of Diesel feed stock

TABLE 2 Process conditions

Table 2 Process conditions

TABLE 3 test results

Wherein the cutting temperature of the heavy fraction and the light fraction of the catalytic diesel oil is 260 ℃.

It can be seen from the examples that the flexible hydro-upgrading process of the present invention achieves the purpose of producing high quality diesel products and high quality catalytic cracking feedstocks by withdrawing a portion of the reactant stream from the hydrofining reactor and using the hydro-upgrading catalyst and the supplemental catalyst, and the production mode is flexible.

Claims

1. A flexible hydro-upgrading process for poor diesel oil comprises the following steps:

2. The hydro-upgrading process of claim 1, further comprising step e: and d, mixing the hydro-upgrading high-pressure hydrogen-rich gas obtained in the step c with the supplementary hydro-refining high-pressure hydrogen-rich gas obtained in the step d for recycling.

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

4. The hydro-upgrading process according to claim 3, wherein the poor quality diesel raw oil is at least one selected from the group consisting of naphthenic 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 process according to claim 1, wherein the hydrofining catalyst in step a and step B and the supplementary hydrofining catalyst in step d use VIB group and/or VIII group metals as active components and alumina or silica-containing 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 hydro-upgrading process of claim 1, wherein the hydrofinishing 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 hydro-upgrading process according to claim 1, wherein the partial stream extracted in the step a accounts for 5 to 95 wt% of the raw material oil in terms of liquid phase.

8. The hydro-upgrading process according to claim 7, wherein the partial stream extracted in the step a accounts for 10 to 80wt% of the raw material oil in terms of liquid phase.

9. The hydro-upgrading process of claim 1, wherein the hydrofinishing conditions of step b 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.

10. The hydro-upgrading process of claim 1, wherein the hydro-upgrading catalyst in step c comprises a group VIB and/or group VIII metal as an active component, a catalyst carrier comprises alumina and a molecular sieve, and the molecular sieve is a Y-type molecular sieve, a beta-type molecular sieve or a SAPO-type molecular sieve.

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

12. The hydro-upgrading process of claim 1, wherein the hydro-upgrading of step c is performed under conditions selected from the group consisting of: 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.

13. The hydro-upgrading process of claim 1, wherein the hydrofinishing conditions of step d 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.

14. A hydro-upgrading method for poor diesel oil comprises the following steps:

15. The hydro-upgrading method according to claim 14, wherein the weight percentage of the light fraction entering the supplementary hydro-upgrading reactor to the light fraction obtained in the step a is 10% to 100%, and the weight percentage of the light fraction entering the second hydro-upgrading catalyst bed layer of the hydro-upgrading reactor to the light fraction obtained in the step a is 0 to 90%.