Catalyst and process for catalytic steam cracking of heavy distillate

Patent metadata

Field	Value
Publication number	US-11225612-B2
Application number	US-202016832519-A
Country	US
Kind code	B2
Filing date	Mar 27, 2020
Priority date	Mar 27, 2020
Publication date	Jan 18, 2022
Grant date	Jan 18, 2022

Abstract

Embodiments of the disclosure provide a method for producing light olefins from a hydrocarbon feed. The hydrocarbon feed and a water feed are introduced to a reactor to produce an effluent stream. The reactor is operated at a temperature and pressure such that cracking reactions occur in the reactor. The reactor includes a catalyst bed including a nanoscale zeolite catalyst having a crystal size ranging between 10 nm and 300 nm. The effluent stream includes the light olefins. The effluent stream is introduced to a first separator to produce a gas phase fraction and a liquid phase fraction. The gas phase fraction includes the light olefins. The liquid phase fraction is introduced to a second separator to produce a liquid hydrocarbon stream and a spent water stream.

First claim

What is claimed is:

1. A method for producing light olefins from a hydrocarbon feed, the method comprising the steps of:
introducing the hydrocarbon feed and a water feed to a reactor to produce an effluent stream, wherein the hydrocarbon feed and the water feed are introduced at a water-to-oil mass flow ratio of about 4, wherein the reactor is operated at a temperature and pressure such that cracking reactions occur in the reactor, wherein the reactor includes a catalyst bed consisting essentially of a nanoscale zeolite catalyst having a crystal size ranging between 10 nm and 300 nm, wherein the reactor is operated at a nanoscale zeolite catalyst-to-oil mass ratio at about 0.5 per cracking cycle, wherein the effluent stream comprises the light olefins;
introducing the effluent stream to a first separator to produce a gas phase fraction and a liquid phase fraction, wherein the gas phase fraction comprises the light olefins; and
introducing the liquid phase fraction to a second separator to produce a liquid hydrocarbon stream and a spent water stream.

2. The method of claim 1 , wherein the hydrocarbon feed is selected from the group consisting of: an atmospheric gasoil, a light vacuum gasoil, and combinations of the same.

3. The method of claim 1 , wherein the nanoscale zeolite catalyst is selected from the group consisting of: a BEA type, a ZSM-5 type, and combinations of the same.

4. The method of claim 3 , wherein the nanoscale zeolite catalyst is a mixture of 90 to 99 wt. % of the BEA type and 1 to 10 wt. % of the ZSM-5 type, wherein the gas phase fraction has an ethylene content ranging between 3 and 7 wt. % and a butenes content ranging between 23 and 30 wt. %.

5. The method of claim 3 , wherein the nanoscale zeolite catalyst is a mixture of 40 to 60 wt. % of the BEA type and 40 to 60 wt. % of the ZSM-5 type, wherein the gas phase fraction has an ethylene content ranging between 8 and 12 wt. % and a butenes content ranging between 16 and 22 wt. %.

6. The method of claim 3 , wherein the nanoscale zeolite catalyst is a mixture of 1 to 10 wt. % of the BEA type and 90 to 99 wt. % of the ZSM-5 type, wherein the gas phase fraction has an ethylene content ranging between 13 and 20 wt. % and a butenes content ranging between 10 and 15 wt. %.

7. The method of claim 1 , wherein the reactor includes silica carbide positioned above and in contact with the catalyst bed.

8. The method of claim 1 , wherein the nanoscale zeolite catalyst is extruded with an alumina binder.

9. The method of claim 8 , wherein the alumina binder content of the nanoscale zeolite catalyst ranges between 10 wt. % and 70 wt. %.

10. The method of claim 8 , wherein the nanoscale zeolite catalyst has a silica-to-alumina mass ratio ranging between 10 and 200.

11. The method of claim 1 , wherein the nanoscale zeolite catalyst has a mesopore-to-micropore volume ratio ranging between 0.5 and 1.5.

12. The method of claim 1 , wherein the nanoscale zeolite catalyst has a total acid site concentration ranging between 0.2 mmol/g and 2.5 mmol/g.

13. The method of claim 12 , wherein the nanoscale zeolite catalyst has a of BrΠnsted acid site concentration ranging between 0.05 mmol/g and 1.0 mmol/g.

14. The method of claim 1 , wherein the effluent stream and the gas phase fraction further comprise hydrogen.

15. The method of claim 1 , wherein the reactor is operated at a temperature ranging between 590 deg. C. and 650 deg. C.

16. The method of claim 1 , wherein the hydrocarbon feed is introduced to the reactor at a space velocity ranging between 0.25 h −1 and 5 h −1 .

17. The method of claim 1 , wherein the water feed is introduced to the reactor at a space velocity ranging between 0.5 h −1 and 20 h −1 .

18. The method of claim 1 , further comprising the step of:
regenerating the nanoscale zeolite catalyst, comprising the steps of:
evacuating internal fluids of the reactor; and
introducing a regeneration gas to the reactor while maintaining the reactor at a temperature ranging between 650 deg. C. and 750 deg. C.

19. The method of claim 18 , wherein the regeneration gas comprises oxygen.

20. The method of claim 18 , wherein the regeneration gas is introduced to the reactor for a duration ranging between 15 minutes and 30 minutes.

21. The method of claim 18 , wherein the regenerating step is continued until the regeneration gas exiting the reactor has a carbon dioxide content less than 0.05 wt. %.

Assignees

• Saudi Arabian Oil Co

Inventors

• Al-Shafei Emad Naji
• Al-Bahar Mohammed Z
• Al-Jishi Ali Nader
• Choi Ki-Hyouk
• Al-Jishi Mohammad F
• Al-Nasir Ali S

Classifications

• B01J35/70

  characterised by their crystalline properties, e.g. semi-crystalline (catalysts comprising carbon B01J21/18; molecular sieves B01J29/00) · CPC title

• B01J35/45

  Nanoparticles · CPC title

• B01J35/77

  Compounds characterised by their crystallite size · CPC title

• B01J35/40

  characterised by dimensions, e.g. grain size (in a colloidal state B01J35/23; crystallite size B01J35/77) · CPC title

• B01J38/12

  Treating with free oxygen-containing gas · CPC title