Wax Oil Hydrocracking Method and System

• US 20190201882A1
• Filed: 12/28/2018
• Published: 07/04/2019
• Est. Priority Date: 12/29/2017
• Status: Active Grant

• Current Assignee: China Petroleum & Chemical Corporation (Central People's Government of The People's Republic of China), Dalian Research Institute of Petroleum and Petrochemicals, Sinopec Corp.
• Original Assignee: China Petroleum & Chemical Corporation (Central People's Government of The People's Republic of China), Dalian Research Institute of Petroleum and Petrochemicals, Sinopec Corp.
• Inventors: LIU, Tao, LI, Baozhong, ZENG, Ronghui, ZHAO, Yuzhuo, BAI, Zhenmin, FANG, Xiangchen, WANG, Yan, ZHANG, Xuehui, LIU, Chang
• Granted Patent: US 10,639,618 B2
• Time in Patent Office: Days
• CPC Class Codes: B01J 2229/36 Steaming
• CPC Class Codes: B01J 29/7007 Zeolite Beta
• CPC Class Codes: B01J 29/80 Mixtures of different zeolites
• CPC Class Codes: C10G 65/00 Treatment of hydrocarbon oils by two or more hydrotreatment processes only
• CPC Class Codes: C10G 65/12 including cracking steps and other hydrotreatment steps
• CPC Class Codes: C10G 65/14 plural parallel stages only

Abstract

A method of wax oil hydrocracking includes the steps of pre-hydrotreating wax oil to obtain a pre-hydrotreated material flow; controlling the pre-hydrotreated material flow and a hydrogen-containing material flow to contact with a first hydrocracking catalyst to obtain a first hydrocracked material flow, and dividing the first hydrocracked material flow into a first hydrocracked material flow A and a first hydrocracked material flow B; controlling the flow B and a hydrogen-containing material flow to contact with a second hydrocracking catalyst to obtain a second hydrocracked material flow, and then separating and fractionating the second hydrocracked material flow to obtain a hydrocracked tail oil product; controlling the flow A, at least a part of the hydrocracked tail oil product, and a hydrogen-containing material flow to contact with a hydrogenation isocracking catalyst to obtain a hydrogenation isocracked material flow, and then separating and fractionating the obtained hydrogenation isocracked material flow.

Claims

1. A wax oil hydrocracking method, comprising:

(1) controlling wax oil as feedstock and a hydrogen-containing material flow to contact with a pre-hydrotreating catalyst under pre-hydrotreating conditions to obtain a pre-hydrotreated material flow;

(2) controlling the pre-hydrotreated material flow and a hydrogen-containing material flow to contact with a first hydrocracking catalyst to have a first hydrocracking reaction under first hydrocracking conditions to obtain a first hydrocracked material flow, and dividing the first hydrocracked material flow into two parts, i.e., a first hydrocracked material flow A and a first hydrocracked material flow B;

(3) controlling the first hydrocracked material flow B and a hydrogen-containing material flow to contact with a second hydrocracking catalyst to have a second hydrocracking reaction under second hydrocracking condition to obtain a second hydrocracked material flow, and then separating and fractionating the second hydrocracked material flow to obtain a hydrocracked tail oil product; and

(4) controlling the first hydrocracked material flow A, at least a part of the hydrocracked tail oil product, and a hydrogen-containing material flow to contact with a hydrogenation isocracking catalyst to have a hydrogenation isocracking reaction under hydrogenation isocracking conditions to obtain a hydrogenation isocracked material flow, and then separating and fractionating the hydrogenation isocracked material flow.

2. The method according to claim 1, wherein the first hydrocracked material flow A accounts for 5-95 wt % of the wax oil.

3. The method according to claim 2, wherein the first hydrocracked material flow A accounts for 10-80 wt % of the wax oil.

4. The method according to claim 1, wherein the method further comprising:

separating the first hydrocracked material flow A by gas-liquid separation to obtain a first hydrocracked gas-phase material flow and a first hydrocracked liquid-phase material flow;

introducing the first hydrocracked gas-phase material flow into the step (3) to carry out the second hydrocracking reaction;

controlling the first hydrocracked liquid-phase material flow, at least a part of the hydrocracked tail oil product and the hydrogen-containing material flow to contact with the hydrogenation isocracking catalyst in the step (4) to carry out the hydrogenation isocracking reaction;

the first hydrocracked liquid-phase material flow accounts for 5-95 wt % of the wax oil.

5. The method according to claim 4, wherein the first hydrocracked liquid-phase material flow accounts for 10-80 wt % of the wax oil.

6. The method according to claim 1, wherein a hydrocracked hydrogen-rich gas, a hydrocracked gas product, a hydrocracked naphtha product, a hydrocracked jet fuel product, a hydrocracked diesel oil product, and the hydrocracked tail oil product are obtained through the separation and fractionation in the step (3);

a hydrogenation isocracked hydrogen-rich gas, a hydrogenation isocracked gas product, a hydrogenation isocracked naphtha product, a hydrogenation isocracked jet fuel product, a hydrogenation isocracked diesel oil product, and a hydrogenation isocracked tail oil product are obtained through the separation and fractionation in the step (4).

7. The method according to claim 6, wherein the separation in the step (3) comprises high-pressure separation and low-pressure separation, the second hydrocracked material flow is separated by high-pressure separation to obtain a hydrocracked hydrogen-rich gas and a hydrocracked high-pressure separated liquid-phase material flow, then the hydrocracked high-pressure separated liquid-phase material flow is separated by low-pressure separation to obtain a hydrocracked gas product and a hydrocracked liquid-phase material flow, the hydrocracked liquid-phase material flow is fractionated to obtain a hydrocracked naphtha product, a hydrocracked jet fuel product, a hydrocracked diesel oil product, and the hydrocracked tail oil product;

the separation in the step (4) comprises high-pressure separation and low-pressure separation, the hydrogenation isocracked material flow is separated by high-pressure separation to obtain a hydrogenation isocracked hydrogen-rich gas and a hydrogenation isocracked high-pressure separated liquid-phase material flow, and then the hydrogenation isocracked high-pressure separated liquid-phase material flow is separated by low-pressure separation to obtain a hydrogenation isocracked gas product and a hydrogenation isocracked liquid-phase material flow, the hydrogenation isocracked liquid-phase material flow is fractionated to obtain a hydrogenation isocracked naphtha product, a hydrogenation isocracked jet fuel product, a hydrogenation isocracked diesel oil product, and a hydrogenation isocracked tail oil product;

the method further comprises;

recycling the hydrocracked hydrogen-rich gas and the hydrogenation isocracked hydrogen-rich gas to provide required hydrogen-containing material flow.

8. The method according to claim 1, wherein the initial boiling point of the wax oil is 100-400°

C., and the final boiling point of the wax oil is 405-650°

C.;

the wax oil is selected from at least one of vacuum gas oil (VGO), coker gas oil (CGO), deasphalted oil (DAO), catalytic cycle oil, coal tar, direct coal liquefaction distillate (DCLD), indirect coal liquefaction distillate (ICLD), synthetic oil, and shale oil;

the initial boiling point of the hydrocracked tail oil product is 300-375°

C.

9. The method according to claim 1, wherein the pre-hydrotreating catalyst contains a carrier and an active component, wherein, the active component is selected from at least one of VIB and/or VIII metal elements, and the carrier is alumina and/or silicon-containing alumina;

based on the total weight of the pre-hydrotreating catalyst and measured in oxide, the content of the VIB metal element is 10-35 wt %, and the content of the VIII metal element is 3-15 wt %;

the specific surface area of the pre-hydrotreating catalyst is 100-650 m²/g, and the pore volume of the pre-hydrotreating catalyst is 0.15-0.6 mL/g.

10. The method according to claim 1, wherein the pre-hydrotreating conditions include:

reaction pressure;

3-19 MPa, reaction temperature;

300-450°

C., liquid hourly space velocity;

0.2-6 h<sup>−

1</sup>, and volume ratio of hydrogen to oil;

100-2,000;

1.

11. The method according to claim 1, wherein the first hydrocracking catalyst and the second hydrocracking catalyst respectively and independently contain a carrier and an active constituent, wherein, the active constituent is selected from at least one of VIB and/or VIII metal elements, and the carrier contains a Y zeolite;

based on the total weight of the first hydrocracking catalyst and measured in oxide, the content of the VIB metal element is 10-35 wt %, and the content of the VIII metal element is 3-15 wt %;

the content of the Y zeolite is 5-80 wt %;

based on the total weight of the second hydrocracking catalyst and measured in oxide, the content of the VIB metal element is 10-35 wt %, and the content of the VIII metal element is 3-15 wt %;

the content of the Y zeolite is 5-80 wt %.

12. The method according to claim 1, wherein the first hydrocracking conditions and the second hydrocracking conditions respectively and independently include:

reaction pressure;

3-19 MPa, reaction temperature;

300-450°

C., liquid hourly space velocity;

0.2-6 h<sup>−

1</sup>, and volume ratio of hydrogen to oil;

100-2,000;

1.

13. The method according to claim 1, wherein the hydrocracked tail oil product in the step (4) accounts for 10-100 wt % of the hydrocracked tail oil product obtained in the step (3).

14. The method according to claim 1, wherein the hydrogenation isocracking catalyst contains a carrier and an active constituent, wherein, the active constituent is selected from at least one of VIB and/or VIII metal elements, and the carrier contains a beta zeolite and/or a SAPO zeolite;

based on the total weight of the hydrogenation isocracking catalyst and measured in oxide, the content of the VIB metal element is 10-35 wt %, the content of the VIII metal element is 3-15 wt %, and the content of the beta zeolite and/or SAPO zeolite is 5-80 wt %.

15. The method according to claim 1, wherein the hydrogenation isocracking conditions include:

reaction pressure;

3-19 MPa, reaction temperature;

300-450°

C., liquid hourly space velocity;

0.2-6 h<sup>−

1</sup>, and volume ratio of hydrogen to oil;

100-2,000;

1.

16. A wax oil hydrocracking system, comprising:

a pre-hydrotreating unit (1);

a first hydrocracking unit (2), in which a pre-hydrotreated material flow obtained from the pre-hydrotreating unit (1) is treated by first hydrocracking to obtain a first hydrocracked material flow;

a second hydrocracking unit (3), in which a part of the first hydrocracked material flow is treated by second hydrocracking to obtain a second hydrocracked material flow;

a hydrocracking separation unit, in which the second hydrocracked material flow is separated to obtain a hydrocracked hydrogen-rich gas, a hydrocracked gas product, and a hydrocracked liquid-phase material flow;

a hydrocracking fractionation tower (5), in which the hydrocracked liquid-phase material flow is fractionated to obtain a hydrocracked tail oil product;

a hydrogenation isocracking reactor (6), in which the remaining part of the first hydrocracked material flow and at least a part of the hydrocracked tail oil product are treated by hydrogenation isocracking to obtain a hydrogenation isocracked material flow;

a hydrogenation isocracking separation unit, in which the hydrogenation isocracked material flow is separated to obtain a hydrogenation isocracked hydrogen-rich gas, a hydrogenation isocracked gas product, and a hydrogenation isocracked liquid-phase material flow; and

a hydrogenation isocracking fractionation tower (8), in which the hydrogenation isocracked liquid-phase material flow is fractionated.

17. The system according to claim 16, wherein the system further comprising:

a gas-liquid separator (9) configured to perform gas-liquid separation of the remaining part of the first hydrocracked material flow to obtain a first hydrocracked gas-phase material flow and a first hydrocracked liquid-phase material flow, the first hydrocracked gas-phase material flow is fed into the second hydrocracking unit (3), and the first hydrocracked liquid-phase material flow is fed into the hydrogenation isocracking reactor (6).

18. The system according to claim 16, wherein the hydrocracking separation unit comprises a hydrocracking high-pressure separator (41) and a hydrocracking low-pressure separator (42) that are connected in series, the second hydrocracked material flow is separated in the hydrocracking high-pressure separator (41) to obtain a hydrocracked hydrogen-rich gas and a hydrocracked high-pressure separated liquid-phase material flow;

the hydrocracked high-pressure separated liquid-phase material flow is separated in the hydrocracking low-pressure separator (42) to obtain a hydrocracked gas product and the hydrocracked liquid-phase material flow;

the hydrogenation isocracking separation unit comprises a hydrogenation isocracking high-pressure separator (71) and a hydrogenation isocracking low-pressure separator (72), the hydrogenation isocracked material flow is separated in the hydrogenation isocracking high-pressure separator (71) to obtain a hydrogenation isocracked hydrogen-rich gas and a hydrogenation isocracked high-pressure separated liquid-phase material flow;

the hydrogenation isocracked high-pressure separated liquid-phase material flow is separated in the hydrogenation isocracking low-pressure separator (72) to obtain a hydrogenation isocracked gas product and the hydrogenation isocracked liquid-phase material flow.

19. The system according to claim 18, wherein the gas phase outlet of the hydrocracking high-pressure separator (41) and the gas phase outlet of the hydrogenation isocracking high-pressure separator (71) respectively and independently communicate with at least one of the inlet of the pre-hydrotreating unit (1), the inlet of the first hydrocracking unit (2), the inlet of the second hydrocracking unit (3), and the inlet of the hydrogenation isocracking reactor (6), to recycle the hydrocracked hydrogen-rich gas and the hydrogenation isocracked hydrogen-rich gas so as to provide a hydrogen-containing material flow required for the system.

20. The system according to claim 16, wherein the pre-hydrotreating unit (1), the first hydrocracking unit (2), and the second hydrocracking unit (3) are arranged in one hydrogenation reactor;

or

the pre-hydrotreating unit (1), the first hydrocracking unit (2), and the second hydrocracking unit (3) are respectively arranged in different hydrogenation reactors;

or

the pre-hydrotreating unit (1) is arranged in a hydrogenation reactor separately, and the first hydrocracking unit (2) and the second hydrocracking unit (3) are arranged in a hydrogenation reactor together.