CN109988618B

CN109988618B - Flexible single-stage two-agent hydrocracking process

Info

Publication number: CN109988618B
Application number: CN201711469372.9A
Authority: CN
Inventors: 刘涛; 赵玉琢; 张学辉; 刘野; 李宝忠; 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: 2021-05-04
Anticipated expiration: 2037-12-29
Also published as: CN109988618A

Abstract

The invention discloses a flexible single-stage two-agent hydrocracking process. Mixing a wax oil raw material with hydrogen, then feeding the mixture into a single-section two-agent hydrocracking reactor, and dividing the material passing through an upper hydrogenation pretreatment catalyst and a single-section hydrocracking catalyst bed into two strands; one material is pumped out of the single-stage reactor through the middle of the bed layer and enters a hydro-isomerization cracking reactor for isomerization cracking reaction; the other material continuously flows downwards through a single-section hydrocracking catalyst bed layer at the lower part; and respectively separating and fractionating the single-stage hydrocracking reaction material and the hydroisomerization cracking reaction material to obtain distillate oil and tail oil products with different specifications. The invention provides a single-stage two-agent hydrocracking process for simultaneously producing more than two different specifications of light naphtha, heavy naphtha, aviation kerosene, diesel oil and tail oil products on a set of hydrocracking process device, which can fully utilize the heat carried by part of cracked materials to realize the coupling operation of a single-stage two-agent hydrocracking reactor and a hydroisomerization cracking reactor.

Description

Flexible single-stage two-agent hydrocracking process

Technical Field

The invention belongs to the field of petroleum refining, and particularly relates to a single-stage two-agent hydrocracking process for flexibly producing high-quality naphtha, aviation kerosene, diesel oil and tail oil products with different properties.

Background

The hydrogenation technology is an important processing means for the lightening of heavy oil and the upgrading of the quality of light oil. The hydrocracking technology has the advantages of strong raw oil adaptability, good product flexibility, high liquid product yield, high product quality and the like, and is developed quickly. The existing hydrocracking technology can be divided into three types according to the processing flow: a one-stage series hydrocracking process flow, a single-stage hydrocracking process flow and a two-stage hydrocracking process flow. The operation can be divided into three types according to whether the tail oil is circulated or not: a single-pass once-through process flow, a partial circulation process flow and a full circulation process flow. The catalyst used in the single-stage hydrocracking technology is mainly a type of single-stage hydrocracking catalyst, the using amount of the catalyst usually accounts for more than 80% of the volume of the total catalyst, the volume of the hydrogenation pretreatment catalyst in the single-stage two-agent hydrocracking technology accounts for more than 20% of the volume of the total catalyst, and the cracking component of the used hydrocracking catalyst is mainly amorphous silica-alumina, and can also contain a small amount of Y-type molecular sieve, beta-type molecular sieve, SAPO series molecular sieve, ZSM-5 molecular sieve and the like. When different types of hydrocracking components are used, the composition and the property of the obtained light oil are greatly different, and the composition and the property of tail oil are also greatly different.

CN001952062A discloses a single-stage two-agent hydrocracking method, relating to a hydrocracking process for producing more middle distillate by using a hydrogenation pretreatment catalyst and a hydrocracking catalyst in a grading way; CN100569921C discloses a single-stage hydrocracking method, which is a single-stage hydrocracking process using a hydrogenation pretreatment catalyst prepared by a bulk phase method; CN001075550C discloses a single-stage hydrocracking method, which is a single-stage hydrocracking process using a single-stage hydrocracking catalyst containing a Y-type molecular sieve; CN001415707A discloses a method for increasing yield of high quality diesel oil by distillate oil, which fills a hydrocracking catalyst containing isomerization performance at the back of the original hydrocracking catalyst to achieve the purpose of reducing the condensation point of the hydrocracking product, but the products of each fraction obtained by the above hydrocracking processes have only one specification.

CN001566283A, CN001766051A, CN101402048A and the like all disclose a medium oil type hydrocracking catalyst and a preparation method thereof, and a single-stage hydrocracking catalyst taking amorphous silicon-aluminum and a small amount of Y-type molecular sieve as acid centers is prepared; CN001712498A discloses a hydrogenation catalyst for maximum diesel production and its preparation method, the catalyst uses amorphous silica-alumina and modified beta molecular sieve as main cracking center, but the hydrocracking technology using these hydrocracking catalysts can obtain only one specification of each fraction product.

CN103394368B discloses a light oil type hydrocracking catalyst containing a composite molecular sieve, a preparation method and an application thereof, CN103551186B discloses a medium oil type hydrocracking catalyst containing a composite molecular sieve, a preparation method and an application thereof, and US6670295 and US4837396A disclose preparation of a composite molecular sieve catalyst. By using the hydrocracking technology of the catalyst, wax oil can be used as raw oil, various high-quality hydrocracking products can be produced by using a hydrocracking method of a composite molecular sieve hydrocracking catalyst containing a Y-shaped molecular sieve and an isomeric molecular sieve, but the product of each fraction has only one specification and is basically used in a series hydrocracking or hydro-upgrading process.

In conclusion, compared with the existing hydrocracking technology using several different types of cracking center catalysts, the single-stage hydrocracking technology using an amorphous silicon-aluminum single-stage two-agent hydrocracking catalyst or an amorphous silicon-aluminum-Y type molecular sieve single-stage hydrocracking catalyst has the advantages that the freezing point of the obtained aviation kerosene product is relatively high, the smoke point is relatively low, the cetane number of the diesel oil product is high, but the condensation point is relatively high, and the condensation point of the tail oil product is very high and is usually more than 30 ℃; by using a single-stage two-agent hydrocracking technology of an isomeric molecular sieve hydrocracking catalyst, the obtained aviation kerosene has relatively high smoke point, the diesel oil product has low sulfur content and low condensation point, the tail oil density is relatively high, but the content of isomeric hydrocarbon is high, the condensation point is very low and is usually less than 0 ℃. The hydrocracking tail oil products produced by the single-section two-agent hydrocracking process technology have larger difference when the conversion rate is the same, wherein the tail oil using the Y-type molecular sieve catalyst is a high-quality catalytic cracking raw material and a raw material for preparing ethylene by steam cracking, and the tail oil using the heterogeneous molecular sieve catalyst is a raw material which can be used for directly producing high-quality lubricating oil base oil or used as high-quality lubricating oil base oil. Therefore, when the above hydrocracking processes are used alone, different types of single-stage two-agent hydrocracking catalysts can be selected according to requirements, or two molecular sieve composite catalysts are used, or two hydrocracking catalysts are selected for use in a grading manner, but the processes can only produce tail oil products with one property, namely the operation flexibility is relatively poor.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a flexible single-stage two-agent hydrocracking process, namely, part of reaction material flow is extracted from the middle part of a single-stage two-agent hydrocracking reactor using a hydrogenation pretreatment catalyst and a single-stage hydrocracking catalyst, and the wax oil raw oil is flexibly produced into various high-quality hydrocracking tail oil products, naphtha products with various specifications and high-quality motor fuel products with various specifications by a single-stage hydrocracking catalyst hydrocracking and heterogeneous hydrocracking catalyst hydrocracking combined method.

The invention relates to a flexible single-section two-agent hydrocracking process method, which comprises the following steps:

a. firstly, wax oil raw oil passes through a hydrogenation pretreatment catalyst bed layer and a single-stage hydrocracking catalyst bed layer on the upper part of a single-stage two-agent hydrocracking reactor under the condition of single-stage two-agent hydrocracking to obtain a first single-stage hydrocracking material flow, the first single-stage hydrocracking material flow is divided into two parts, and one part of the first single-stage hydrocracking material flow is extracted out of the single-stage two-agent hydrocracking reactor;

b. b, continuously enabling the rest part of the first single-stage hydrocracking material flow in the step a to pass through a single-stage hydrocracking catalyst bed layer at the lower part of a single-stage two-agent hydrocracking reactor under a hydrocracking condition, and separating and fractionating the single-stage two-agent hydrocracking material flow to obtain a single-stage two-agent hydrocracking high-pressure hydrogen-rich gas, a single-stage two-agent hydrocracking gas product, a single-stage two-agent hydrocracking naphtha product, a single-stage two-agent hydrocracking aviation kerosene product, a single-stage two-agent hydrocracking diesel oil product and a single-stage two-agent hydrocracking tail oil product;

c. and a, allowing the first single-stage hydrocracking material flow extracted from the reactor in the step a to pass through a single-stage hydrocracking catalyst bed layer containing heterogeneous molecular sieve catalysts of a single-stage hydrocracking reactor under a single-stage hydroisomerization cracking condition, and separating and fractionating the single-stage hydrocracking material flow to obtain a single-stage hydroisomerization cracking high-pressure hydrogen-rich gas, a single-stage hydroisomerization cracked gas product, a single-stage hydroisomerization cracked naphtha product, a single-stage hydroisomerization cracked aviation kerosene product, a single-stage hydroisomerization cracked diesel oil product and a single-stage hydroisomerization cracked tail oil product.

The hydrocracking process according to the present invention may further comprise a step d: and c, mixing the single-section two-agent hydrocracking high-pressure hydrogen-rich gas obtained in the step b and the single-section hydroisomerization cracking high-pressure hydrogen-rich gas obtained in the step c for recycling.

S, N, O and other impurities in the wax oil raw oil are effectively removed through a hydrogenation pretreatment catalyst and a single-stage two-agent hydrocracking catalyst, aromatic hydrocarbon is subjected to hydrogenation saturation to a certain extent, cyclic hydrocarbon is subjected to partial ring-opening reaction, macromolecules are cracked into small molecules, and a part of single-stage hydrocracking material flow is continuously subjected to single-stage hydrocracking to obtain a aviation kerosene product, a diesel oil product and a tail oil product, wherein the aviation kerosene product has a high normal hydrocarbon content and a low aromatic hydrocarbon content; and (3) after a part of the extracted first single-stage hydrocracking material flow passes through a hydroisomerization cracking catalyst containing an isomerization type molecular sieve catalyst, continuing isomerization hydrocracking, wherein the isomerization hydrocracking product with high isomerization hydrocarbon content, especially the diesel oil and diesel oil product, has low condensation point, the tail oil product and high viscosity index, because the isomerization hydrocracking catalyst has the characteristics of isomerization and cracking.

Compared with the prior art, the flexible single-section two-agent hydrocracking process has the advantages that:

1. in the invention, the single-section two-agent hydrocracking reactor comprises at least two single-section hydrocracking catalyst beds. Through the step of extracting the cracked materials arranged in the middle of the bed layer of the single-stage hydrocracking reactor, effective distribution of single-stage two-agent hydrocracking material strands can be realized without special operation, and the obtained materials are subjected to different hydrocracking processes, so that target products with different specifications, particularly tail oil products, 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, although a plurality of light products can be obtained by adjusting the conversion rate and the distillation range of the products, the same distillation range of a single-stage hydrocracking device can only be used for one type of light naphtha products, heavy naphtha products, aviation kerosene products, diesel oil products and tail oil products generally because only one single-stage two-agent hydrocracking reactor is provided; if the hydrocracking products with different specifications are required, more than two sets of single-section two-agent hydrocracking devices are required. Therefore, the invention provides a single-stage two-agent hydrocracking process for simultaneously producing more than two same-fraction ranges but different specifications of tail oil products, more than two different specifications of aviation kerosene products, more than two different specifications of diesel oil products and a plurality of different specifications of naphtha products on a single-stage two-agent hydrocracking process device for the first time.

2. According to the invention, the first hydrocracking material flow extracting device is arranged in the middle of the catalyst bed layer of the single-section two-agent hydrocracking reactor, the first single-section hydrocracking material flow of the wax oil raw material subjected to single-section two-agent hydrocracking is extracted out of the reactor and is sent into the separately arranged hydroisomerization cracking reactor for hydroisomerization cracking reaction, and the condensation point of the hydrocracked material is further reduced, so that naphtha products, aviation kerosene products, diesel oil products and tail oil products with different aromatic hydrocarbon contents and different isomeric hydrocarbon contents can be flexibly produced by the method.

3. In the invention, heavy naphtha obtained by hydrocracking a product obtained by fractionating the material flows of two reactors by a hydrocracking catalyst containing a single-stage hydrocracking catalyst or a hydrocracking catalyst containing a small amount of Y-type molecular sieve has relatively high aromatic hydrocarbon potential, a aviation kerosene product has relatively high smoke point, a diesel oil product has relatively high cetane number, a tail oil product has high paraffin content and a BMCI value is relatively low; the naphtha obtained by partial hydrocracking containing a single-stage hydrocracking catalyst and the hydroisomerization cracking containing an isomeric molecular sieve catalyst has high content of isomeric hydrocarbon, a aviation kerosene product has low freezing point, a diesel oil product has low freezing point, and a tail oil product has high content of isomeric hydrocarbon, large viscosity index and low freezing point; can respectively meet the requirements of producing naphtha, aviation kerosene products, diesel oil products and tail oil products with different specifications.

4. In the invention, the liquid obtained in the middle of the single-section hydrocracking catalyst bed of the single-section two-agent hydrocracking reactor has very high temperature and pressure, and can directly enter a newly arranged hydroisomerization cracking reactor for reaction, thereby fully utilizing the heat carried by the part of cracking materials and realizing the coupling operation of the hydroisomerization cracking reactor and the single-section hydrocracking reactor.

Drawings

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

Wherein: 1-raw oil, 2-hydrocracking reactor, 3-hydrocracking material flow, 4-hydroisomerization cracking material flow, 5-hydroisomerization cracking reactor, 6-hydrocracking high-pressure separator hydrogen-rich gas, 7-hydroisomerization cracking high-pressure separator hydrogen-rich gas, 8-hydrocracking high-pressure separator, 9-hydroisomerization cracking high-pressure separator, 10-hydrocracking fractionating tower, 11-hydroisomerization cracking fractionating tower, 12-hydrocracking light naphtha product, 13-hydrocracking heavy naphtha product, 14-hydrocracking aviation kerosene product, 15-hydrocracking diesel oil product, 16-hydrocracking tail oil product, 17-hydroisomerization cracking light naphtha product, 18-hydrocracking heavy naphtha product, 19-hydroisomerized cracked aviation kerosene product, 20-hydroisomerized cracked diesel oil product, 21-hydroisomerized cracked tail oil product, 22-make-up hydrogen and 23-recycle hydrogen.

Detailed Description

The initial boiling point of the wax oil raw material in the step a is 100-400 ℃, and the final boiling point is 405-620 ℃. The wax oil raw material oil can be one of straight-run wax oil, coking wax oil, deasphalted oil, catalytic cycle oil and the like obtained by petroleum processing, one of coal tar, coal direct liquefaction oil, coal indirect liquefaction oil, synthetic oil, shale oil and the like obtained from coal, and can also be mixed oil of a plurality of the coal tar, the coal direct liquefaction oil, the coal indirect liquefaction oil, the synthetic oil and the shale oil.

The hydrogenation pretreatment catalyst in the step a is a conventional wax oil hydrogenation pretreatment catalyst. Generally, metals in a VIB group and/or a VIII group are used as active components, alumina or silicon-containing alumina is used as a carrier, the metals in the VIB group are generally Mo and/or W, and the metals in the VIII group are generally Co and/or Ni. Based on the weight of the catalyst, the content of the VIB group metal is 10-35 wt% calculated by oxide, 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. The main catalysts comprise 3936, 3996, FF-16, FF-26, FF-36, FF-46, FF-56 series and the like which are developed and researched by petrochemical research instituteThe hydrogen pretreatment catalyst may be a similar catalyst developed by catalyst companies at home and abroad, such as HC-K, HC-P of UOP, TK-555, TK-565 catalysts of Topsoe, KF-847, KF-848 of Akzo, and the like. The operation conditions can adopt the conventional operation conditions, generally the reaction pressure is 3.0MPa to 19.0MPa, the reaction temperature is 300 ℃ to 450 ℃, and the liquid hourly volume space velocity is 0.2h^-1～6.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

The single-stage hydrocracking catalyst in the step a is a conventional wax oil single-stage hydrocracking 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, and the molecular sieve can be Y-type 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, and the content of the molecular sieve is 0-40 wt%. The main catalysts comprise ZHC-01, ZHC-02, ZHC-03, ZHC-04, FC-28, FC-34 catalysts and the like which are developed by the petition petrochemical research institute, TK-925, TK-951 and the like which are developed and developed by Haldor Topsoe, KF-1023 and the like which are developed and developed by the Albemarle. For hydrocracking catalysts, certain hydrogenation activity and certain cracking activity are required, so that hydrogenation saturation of olefins and aromatics in hydrotreating generated oil and fractions generated in a hydrocracking process is ensured, and ring-opening reaction of saturated aromatics is also required. The hydrocracking operating conditions may be conventional and are generally: the reaction pressure is 3.0MPa to 19.0MPa, the reaction temperature is 300 ℃ to 450 ℃, and the liquid hourly volume space velocity is 0.2h^-1～6.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

In the invention, the volume fraction of the hydrogenation pretreatment catalyst accounts for 20-70% of the total volume of the catalyst in the single-stage hydrocracking reactor, and preferably 30-65%.

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

The separation described in step b generally comprises separating two parts, a hydrocracking high-pressure separator and a low-pressure separator. Wherein the high-pressure separator separates to obtain the hydrocracking 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. The hydrocarbon-rich gas is separated to obtain the required hydrocracking gas product.

The fractionation described in step b is carried out in a hydrocracking fractionator system. And fractionating the low-pressure liquid product in a fractionating tower to obtain a hydrocracking light naphtha product, a hydrocracking heavy naphtha product, a hydrocracking aviation kerosene product, a hydrocracking diesel oil product and a hydrocracking tail oil product.

The single-stage hydroisomerization cracking catalyst in the step c is a conventional wax oil hydroisomerization cracking 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, and the content of the molecular sieve is 2-40 wt%. The main catalysts comprise FC-14 catalysts developed by the petrochemical research institute. For hydrocracking catalysts, certain hydrogenation activity and certain cracking activity are required, and both the hydrogenation saturation of olefins and aromatics in reaction materials and the isomerization of straight-chain paraffins are required. The hydroisomerization cracking may be carried out under conventional operating conditions, which are generally: the reaction pressure is 3.0MPa to 19.0MPa, the reaction temperature is 300 ℃ to 450 ℃, and the liquid hourly volume space velocity is 0.2h^-1～6.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

The separation described in step c is carried out in a hydroisomerization cracking high pressure separator and a low pressure separator. Wherein, the hydroisomerization cracking high-pressure separator separates to obtain the hydroisomerization cracking 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. The hydrocarbon-rich gas is separated to obtain the required hydroisomerized cracked gas product.

The fractionation described in step c is carried out in a hydroisomerization cracking fractionator system. And fractionating the low-pressure liquid product in a fractionating tower to obtain a hydroisomerized cracked light naphtha product, a hydroisomerized cracked heavy naphtha product, a hydroisomerized cracked aviation kerosene product, a hydroisomerized cracked diesel oil product and a hydroisomerized cracked tail oil product.

The hydrocracking gas product and the hydroisomerization cracking gas product in the steps b and c can be used as products independently or can be mixed into a mixed gas product.

The hydrocracked light naphtha product and the hydroisomerized cracked light naphtha product in the step b and the step c can be used as products independently or can be mixed into a mixed light naphtha product.

The hydrocracked heavy naphtha product and the hydroisomerized cracked heavy naphtha product in the step b and the step c can be used as the products independently or can be mixed into a mixed heavy naphtha product.

The hydrocracking aviation kerosene product and the hydroisomerization cracking aviation kerosene product in the step b and the step c can be used as products independently or can be mixed into a mixed aviation kerosene product.

The hydrocracking diesel oil product and the hydroisomerization diesel oil product in the step b and the step c can be used as products independently or can be mixed into a mixed diesel oil product.

And (c) taking the hydrocracking tail oil in the step b as a product.

And d, independently using the hydroisomerized cracked tail oil in the step c as a product.

And d, mixing the high-pressure hydrogen-rich gas in the step d, 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 single-section two-agent hydrocracking reactor 2, a hydroisomerized cracking raw material flow 4 is extracted from a reactant flow passing through a first hydrocracking catalyst bed layer, the flow after the hydroisomerized cracking raw material flow 4 is extracted continues to enter a subsequent single-section hydrocracking catalyst bed layer, a single-section two-agent hydrocracking generated flow 3 enters a hydrocracking high-pressure separator 8 for gas-liquid separation, the liquid obtained by separation enters a fractionating tower 10 for fractionation to obtain a hydrocracking light naphtha product 12, a hydrocracking heavy naphtha product 13, a hydrocracking aviation kerosene product 14, a hydrocracking diesel oil product 15 and a hydrocracking tail oil product 16, the hydroisomerized cracking raw material flow 4 enters a hydrocracking reactor 5, the generated flow passing through the hydrocracking catalyst bed layer enters a hydrocracking high-pressure separator 9 for gas-liquid separation, the separated liquid enters a fractionating tower 11 to be fractionated to obtain a hydroisomerized cracked light naphtha product 17, a hydroisomerized cracked heavy naphtha product 18, a hydroisomerized cracked aviation kerosene product 19, a hydroisomerized cracked diesel oil product 20 and a hydroisomerized cracked tail oil product 21, the hydroisomerized cracked light naphtha product 12 and the hydroisomerized cracked light naphtha product 17 can be independently used as products or can be mixed to obtain a mixed light naphtha product, the hydroisomerized cracked heavy naphtha product 13 and the hydroisomerized cracked heavy naphtha product 18 can be independently used as products or can be mixed to obtain a mixed heavy naphtha product, the hydroisomerized cracked aviation kerosene product 14 and the hydroisomerized cracked aviation kerosene product 19 can be independently used as products or can be mixed to obtain a mixed aviation kerosene product, the hydroisomerized cracked diesel oil product 15 and the hydroisomerized cracked diesel oil product 20 can be independently used as products, or mixed to obtain a mixed diesel product, and the gas 6 obtained by separating the hydrocracking high-pressure separator 8 and the gas 7 obtained by separating the hydroisomerization high-pressure separator 9 are mixed and then are pressurized by a recycle hydrogen compressor and then are mixed with make-up hydrogen 22 to be used as recycle hydrogen 23.

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 FF-56 is a hydrotreating catalyst developed and produced by the smooth petrochemical research institute of China petrochemical company Limited; the catalyst FC-28 is a single-stage hydrocracking catalyst developed and produced by the smooth petrochemical research institute of China petrochemical company Limited, and contains a Y-type molecular sieve; the catalyst ZHC-02 is a single-stage hydrocracking catalyst which is developed and produced by China petrochemical company Limited, compliant petrochemical research institute and does not contain a molecular sieve; the catalyst FC-14 is a single-stage hydroisomerization cracking catalyst developed and produced by the smooth petrochemical research institute of China petrochemical company Limited and contains a beta-type molecular sieve.

TABLE 1 essential Properties of wax oil base stocks

	Wax oil 1	Wax oil 2
			Density, g/cm³	0.905	0.918
Fraction range, C	320～546	345～560
			Sulfur content, wt.%	1.1	2.0
Nitrogen content, wt%	0.132	0.075
			Freezing point, deg.C	32	34

Table 2 example process conditions

Table 3 example test results

It can be seen from the examples that, the single-stage two-agent hydrocracking process of the present invention can achieve the purpose of producing hydrocracking products of different properties by extracting a part of reactant flow from the single-stage two-agent hydrocracking reactor and using the single-stage hydrocracking catalyst and the single-stage hydroisomerization cracking catalyst, and the production mode is flexible.

Claims

1. A method for a flexible single-stage two-agent hydrocracking process, comprising the steps of:

b. b, continuously enabling the rest part of the first single-stage hydrocracking material flow in the step a to pass through a single-stage hydrocracking catalyst bed layer at the lower part of the single-stage two-agent hydrocracking reactor under the single-stage hydrocracking condition, and separating and fractionating the single-stage two-agent hydrocracking material flow to obtain a single-stage two-agent hydrocracking high-pressure hydrogen-rich gas, a single-stage two-agent hydrocracking gas product, a single-stage two-agent hydrocracking naphtha product, a single-stage two-agent hydrocracking aviation kerosene product, a single-stage two-agent hydrocracking diesel oil product and a single-stage two-agent hydrocracking tail oil product;

c. and a, allowing the first single-stage hydrocracking material flow extracted from the reactor in the step a to pass through a single-stage hydrocracking catalyst bed layer containing an isomeric molecular sieve catalyst of a single-stage hydrocracking reactor under a hydroisomerization cracking condition, and separating and fractionating the single-stage hydrocracking material flow to obtain a single-stage hydroisomerization cracking high-pressure hydrogen-rich gas, a single-stage hydroisomerization cracked gas product, a single-stage hydroisomerization cracked naphtha product, a single-stage hydroisomerization cracked aviation kerosene product, a single-stage hydroisomerization cracked diesel oil product and a single-stage hydroisomerization cracked tail oil product.

2. The process of hydrocracking process according to claim 1, further comprising step d: and c, mixing the single-section two-agent hydrocracking high-pressure hydrogen-rich gas obtained in the step b and the single-section hydroisomerization cracking high-pressure hydrogen-rich gas obtained in the step c for recycling.

3. The hydrocracking process according to claim 1, wherein the wax oil feedstock has an initial boiling point of 100 to 400 ℃ and an end boiling point of 405 to 620 ℃.

4. The hydrocracking process according to claim 3, wherein said wax oil feedstock is at least one selected from the group consisting of straight run wax oil, coker wax oil, deasphalted oil, catalytic cycle oil, coal tar, direct coal liquefaction oil, indirect coal liquefaction oil, synthetic oil and shale oil.

5. The method of claim 1, wherein the volume fraction of the hydrotreating pretreatment catalyst in the single-stage hydrocracking reactor is 20% to 70% by volume based on the total volume of the catalyst.

6. The hydrocracking process of claim 1The hydrogenation pretreatment catalyst is characterized in that VIB group and/or VIII group metals are used as active components, and alumina or silicon-containing alumina is used 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.

7. The hydrocracking process of claim 1, wherein the single-stage hydrocracking catalyst comprises a group VIB and/or group VIII metal as an active component, the catalyst carrier comprises one or more of alumina, siliceous alumina and a molecular sieve, and the molecular sieve is a Y-type molecular sieve.

8. The process of claim 7 wherein the group VIB metal content, as oxide, is from 10wt% to 35wt%, the group VIII metal content, as oxide, is from 3wt% to 15wt%, and the molecular sieve content is from 0wt% to 40wt%, based on the weight of the catalyst.

9. The process of claim 1, wherein the single stage hydrocracking conditions are: the reaction pressure is 3.0MPa to 19.0MPa, the reaction temperature is 300 ℃ to 450 ℃, and the liquid hourly volume space velocity is 0.2h^-1～6.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

10. The hydrocracking process according to claim 1, wherein the partial stream withdrawn in step a is 5 to 95 wt% based on the liquid phase of the feedstock.

11. The hydrocracking process method according to claim 1, wherein the single-stage hydroisomerization cracking catalyst uses group VIB and/or group VIII metals as active components, the catalyst carrier contains a molecular sieve, and the molecular sieve is a beta type molecular sieve or a Sapo type 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, and the content of the molecular sieve is 2-40 wt%.

12. The hydrocracking process according to claim 1, wherein said hydrocracking conditions are: the reaction pressure is 3.0MPa to 19.0MPa, the reaction temperature is 300 ℃ to 450 ℃, and the liquid hourly volume space velocity is 0.2h^-1～6.0h^-1The volume ratio of the hydrogen to the oil is 100: 1-2000: 1.

13. The hydrocracking process according to claim 5, wherein the volume fraction of the hydrotreating pretreatment catalyst based on the total volume of the catalyst in the single-stage hydrocracking reactor is 30 to 65%.

14. The hydrocracking process method according to claim 10, wherein the partial stream withdrawn in step a accounts for 10 to 80 wt% of the feed oil in terms of liquid phase.