Wet start-up method for hydrogenation unit, energy-saving hydrogenation process and hydrogenation apparatus

Patent metadata

Field	Value
Publication number	US-9574141-B2
Application number	US-201314068506-A
Country	US
Kind code	B2
Filing date	Oct 31, 2013
Priority date	Nov 3, 2012
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

The present invention relates to a wet start-up method for hydrogenation unit, an energy-saving hydrogenation process, and a hydrogenation apparatus. The method involves heating a start-up activating oil to a specific temperature and flowing the heated oil through a bed of hydrogenation catalyst bed, so that the temperature at the catalyst bed layer is increased to 180±10° C. or above by means of heat exchange and the reaction heat generated from activation in the start-up method.

First claim

The invention claimed is:

1. A wet start-up method for hydrogenation unit, comprising the following steps:
(a) utilizing a low-temperature heat source to heat up a start-up activating oil, feeding the heated start-up activating oil and a circulating hydrogen into a hydrogenation unit, wherein the hydrogenation unit contains a sulfurized type hydrogenation catalyst, and the sulfurized type hydrogenation catalyst is activated;
(b) stopping the use of the low-temperature heat source, utilizing the reaction heat generated from the activating reaction of the sulfurized type hydrogenation catalyst to heat up materials in the hydrogenation unit to 180±10° C., and then introducing an olefin-rich gas and/or olefin-rich light distillate oil into the hydrogenation unit to carry out olefin hydrogenation reaction;
(c) utilizing the reaction heat generated from the olefin hydrogenation reaction to further heat up the materials in the hydrogenation unit to 230±10° C., and keeping the temperature constant for at least 4 h;
(d) heating the materials in the hydrogenation unit further to a temperature higher than 240° C., reducing the amount of the olefin-rich gas and/or olefin-rich light distillate oil gradually, replacing the start-up activating oil with a feedstock gradually, and utilizing the reaction heat generated from the feedstock hydrogenation reaction to heat up the materials in the hydrogenation unit until the target temperature is reached.

2. The method according to claim 1 , wherein, in step (a), the low-temperature heat source is utilized to heat up the start-up activating oil to the reaction starting temperature of activating the hydrogenation reaction of the sulfurized type hydrogenation catalyst.

3. The method according to claim 1 , wherein, in step (a), the sulfurized type hydrogenation catalyst contains elemental sulfur that serves as a sulfurizing agent.

4. The method according to claim 1 , wherein, in step (a), the mass content of zeolite in the sulfurized type hydrogenation catalyst is lower than 5%.

5. The method according to claim 1 , wherein, in step (a), the sulfurized type hydrogenation catalyst comprises a hydrocracking catalyst that contains zeolite and/or a hydroupgrading catalyst that contains zeolite; based on the total mass of the sulfurized type hydrogenation catalyst, the mass content of zeolite is 5% to 60%; in step (d), ammonia is introduced when the materials are heated up from 230±10° C. to 260±10° C.

6. The method according to claim 5 , wherein, in step (d), the amount of ammonia is introduced so that the total mass concentration of ammonia and ammonium ions in high-pressure separator water is 0.4% to 2.0%.

7. The method according to claim 1 , wherein, in step (a), the circulating hydrogen is a hydrogen-rich high pressure gas; based on the volume of circulating hydrogen, the hydrogen purity of the gas is not lower than 50 vol %.

8. The method according to claim 1 , wherein, in step (a), the start-up activating oil is petroleum distillate which is rich in saturated hydrocarbons; based on the weight of the start-up activating oil, the nitrogen content is not higher than 200 μg/g, the inlet temperature of the hydrogenation unit when the start-up activating oil is introduced is 50° C. to 150° C.

9. The method according to claim 8 , wherein, the start-up activating oil is at least one selected from the group consisting of straight-run jet fuel, straight-run diesel, jet fuel obtained by deep hydrofining, or diesel obtained by deep hydrofining, jet fuel obtained by hydrocracking, and diesel obtained by hydrocracking.

10. The method according to claim 1 , wherein, the start-up process is carried out in existence of hydrogen gas, the volume ratio of hydrogen/oil is 100:1 to 2000:1, and the liquid hourly space velocity is 0.1 to 10.0 h −1 .

11. The method according to claim 1 , wherein, in step (a), the low-temperature heat source is a heat source at 100 to 240° C.

12. The method according to claim 1 , wherein, in step (a), the low-temperature heat source is provided from a low-temperature heat source supplier, which can be at least one selected from the group consisting of steam generator, steam heating system, electric heater, and fractionating tower heating furnace, and the low-temperature heat source supplier communicates with the hydrogenation unit via a heat exchanger.

13. The method according to claim 1 , wherein, in step (b), the olefin-rich gas refers to gaseous hydrocarbons with 5% to 80% mass content of mono-olefins; the olefin-rich light distillate oil refers to liquid hydrocarbons with 10% to 60% mass content of mono-olefins.

14. The method according to claim 1 , wherein, in step (b), the introduction amount of olefin-rich gas and/or olefin-rich light distillate oil is determined according to the required rate of temperature rise.

15. The method according to claim 14 , wherein, the introduction amount of olefin-rich gas is equal to or more than 20% of the volume of make-up hydrogen.

16. The method according to claim 14 , wherein, the introduction amount of olefin-rich light distillate is equal to or less than 80% of the total volume of the feedstock.

17. The method according to claim 1 , wherein, in step (d), the proportion of the feedstock in the materials fed to the hydrogenation unit is increased 2 to 6 times until the start-up activating oil is fully replaced by the feedstock.

18. The method according to claim 1 , wherein, in step (d), the introduction of the olefin-rich gas and/or the olefin-rich light distillate oil is stopped when the temperature reaches or is above 280° C.

19. The method according to claim 1 , wherein, the pressure in the activation process is not higher than the designed operating pressure.

20. An energy-saving hydrogenation process, comprising: utilizing the method set forth in claim 1 to accomplish a wet start-up process, and feeding the feedstock into the hydrogenation unit when the target temperature is reached.

21. The process according to claim 20 , wherein, the method further comprises: exchanging heat between the feedstock with the effluent from the hydrogenation unit and the feedstock to the hydrogenation unit.

22. The method according to claim 1 , wherein, in step (a), the low-temperature heat source is utilized to heat up the start-up activating oil to 80-170° C.

23. The method according to claim 1 , wherein, in step (a), the mass content of zeolite in the sulfurized type hydrogenation catalyst is lower than 2%.

24. The method according to claim 1 , wherein, in step (a), the sulfurized type hydrogenation catalyst comprises a hydrocracking catalyst that contains zeolite and/or a hydroupgrading catalyst that contains zeolite; based on the total mass of the sulfurized type hydrogenation catalyst, the mass content of zeolite is 5% to 60%, and ammonia is introduced starting from the process that when the materials are heated up from 230±10° C. to 260±10° C., and the introduction of ammonia is stopped when the temperature is at or above 280° C.

25. The method according to claim 5 , wherein, in step (d), the amount of ammonia is introduced so that in an amount that ensures the total mass concentration of ammonia and ammonium ions in high-pressure separator water is 0.6% to 1.8%.

26. The method according to claim 1 , wherein, in step (a), the circulating hydrogen is a hydrogen-rich high pressure gas; based on the volume of circulating hydrogen, the hydrogen

Assignees

• China Petroleum & Chem Corp
• Fushun Res Inst Petroleum & Petrochemicals Sinopec

Inventors

• Zeng Ronghui
• Liu Tao
• Fang Xiangchen
• Han Zhaoming
• Zhang Xuehui
• Sun Shike
• Peng Chong
• Guo Rong
• Liu Jihua
• Li Benzhe

Classifications

• C10G2300/1088

  Olefins · CPC title

• C10G49/24 Primary

  Starting-up hydrotreatment operations · CPC title

• C10G2300/4031

  Start up or shut down operations · CPC title