Catalytic cracking process allowing improved upcycling of the calories from the combustion fumes

Patent metadata

Field	Value
Publication number	US-10336948-B2
Application number	US-201514594833-A
Country	US
Kind code	B2
Filing date	Jan 12, 2015
Priority date	Jan 10, 2014
Publication date	Jul 2, 2019
Grant date	Jul 2, 2019

Abstract

The present invention describes a process for the production of gasoline using a catalytic cracking unit, processing conventional heavy cuts in a wide Conradson carbon range from 0.1 to 0.8, said process comprising a preheating of the combustion air downstream of the air compressor by heat exchange with the combustion fumes originating from the regeneration section, said fumes being collected between the waste heat boiler and the economizer.

First claim

The invention claimed is:

1. Process comprising:
catalytic cracking of heavy hydrocarbon cuts wherein said heavy hydrocarbon cuts are VGO or atmospheric residue, using a fluidized bed catalytic cracking unit comprising:
a reaction section with an upward flow or with a downward flow, and
a catalyst regeneration section wherein said catalyst regeneration section consists of combustion of a coke deposited on a catalyst in the reaction section by combustion air, wherein said catalyst regeneration section produces flue gas that exchange calories inside a waste heat boiler, the flue gas from the waste heat boiler is introduced in an electric precipitator (ESP), then in an economizer (ECO) that allows for the production of low pressure superheated steam (LPSH) from low pressure water (LPBFW), and for the production of high pressure superheated water (HPBFW) from high pressure water,
a cat cooler wherein said cat cooler is a fluidized bed exchanger suitable for generating high-pressure steam (HPS) from calories directly contained on a hot catalyst in a process of regeneration,
wherein said combustion air in said process is preheated to a temperature of between 200 and 350° C. by a heat exchange using regeneration fumes collected downstream of a waste heat boiler and upstream of an economizer,
wherein said regeneration fumes at this location are at a temperature of between 300° C. and 650° C., and
wherein the excess calories supplied by the combustion air are converted to high-pressure steam of between 45 and 100 bar at a level of an external exchanger on hot catalyst collected at said cat cooler.

2. The process for the catalytic cracking of hydrocarbon cuts of claim 1 , wherein the reaction section operates with an upward flow with the following operating conditions:
a temperature at a riser outlet of between 520° C. and 600° C.,
a C/O ratio of between 6 and 14,
a residence time of between 1 and 10 s.

3. The process for the catalytic cracking of hydrocarbon cuts of claim 1 , wherein the reaction section operates with a downward flow with the following operating conditions:
a temperature at a riser outlet of between 580° C. and 630° C.,
a C/O ratio of between 15 and 40, and
a residence time of between 0.1 and 1 s.

4. The process for the catalytic cracking of hydrocarbon cuts of claim 1 , wherein the combustion air in said process is preheated to a temperature of between 250° C. and 300° C.

5. The process for the catalytic cracking of hydrocarbon cuts of claim 1 , wherein the high-pressure steam is between 50 and 70 bar.

6. The process for the catalytic cracking of hydrocarbon cuts of claim 2 , wherein the C/O ratio is between 7 and 12.

7. The process for the catalytic cracking of hydrocarbon cuts of claim 2 , wherein the residence time is between 2 and 6 s.

8. The process for the catalytic cracking of hydrocarbon cuts of claim 3 , wherein the C/O ratio is between 20 and 30.

9. The process for the catalytic cracking of hydrocarbon cuts of claim 1 , wherein the residence time is between 0.2 and 7 s.

10. The process for the catalytic cracking of hydrocarbon cuts of claim 1 , wherein the high-pressure steam is used as a heat source in an external process.

11. The process of claim 1 , wherein the cat cooler is a heat exchanger disposed on the side of the regenerator and is suitable for allowing the catalyst to be returned continuously through an outlet disposed on the lower side of the cat cooler.

12. The process of claim 11 , wherein the catalyst particles move in an out the exchanger by gravity and pressure differences.

13. A process comprising:
catalytic cracking of hydrocarbon cuts of wherein said heavy hydrocarbon cuts are VGO or atmospheric residue, using a fluidized bed catalytic cracking unit comprising
a reaction section with an upward flow or with a downward flow, and a catalyst regeneration section which consists of combustion of coke deposited on a catalyst in the reaction section by combustion air, said process comprising no cat cooler, and wherein the combustion air is preheated to a temperature of between 200° C. and 350° C. by a heat exchange using regeneration fumes collected downstream of a waste heat boiler and upstream of an economizer, said regeneration fumes available at this location at a temperature between 300° C. and 650° C., and wherein excess calories are supplied by the combustion air suitable to reduce the consumption of fuel by the furnace for preheating said combustion air.

14. The process for the catalytic cracking of hydrocarbon cuts of claim 13 , wherein the reaction section operates with an upward flow with the following operating conditions:
a temperature at a riser outlet of between 520° C. and 600° C.,
a C/O ratio of between 6 and 14, and
a residence time of between 1 and 10 s.

15. The process for the catalytic cracking of hydrocarbon cuts of claim 13 , wherein the reaction section operates with a downward flow under the following operating conditions:
a temperature at a reactor outlet of between 580° C. and 630° C.,
a C/O ratio of between 15 and 40,
a residence time of between 0.1 and 1 s.

16. The process for the catalytic cracking of hydrocarbon cuts of VGO type or atmospheric residue, using a fluidized bed catalytic cracking unit of claim 13 , wherein the combustion air is preheated to a temperature of between 250° C. and 300° C.

17. The process for the catalytic cracking of hydrocarbon cuts of VGO type or atmospheric residue, using a fluidized bed catalytic cracking unit of claim 14 , wherein the C/O ratio is between 7 and 12.

18. The process for the catalytic cracking of hydrocarbon cuts of VGO type or atmospheric residue, using a fluidized bed catalytic cracking unit of claim 14 , wherein the residence time is between 2 and 6 s.

19. The process for the catalytic cracking of hydrocarbon cuts of VGO type or atmospheric residue, using a fluidized bed catalytic cracking unit of claim 15 , wherein the C/O ratio is between 20 and 30.

20. The process for the catalytic cracking of hydrocarbon cuts of VGO type or atmospheric residue, using a fluidized bed catalytic cracking unit of claim 15 , wherein the residence time is between 0.2 and 0.7 s.

Assignees

• Ifp Energies Now

Inventors

• Feugnet Frederic
• Besnault Jean-Michel
• Briot Patrick

Classifications

• C10G11/182

  Regeneration · CPC title

• C10G11/185 Primary

  Energy recovery from regenerator effluent gases · CPC title

• C10G11/05 Primary

  Crystalline alumino-silicates, e.g. molecular sieves · CPC title

• B01J38/32

  Indirectly heating or cooling material within regeneration zone or prior to entry into regeneration zone · CPC title

• B01J38/12

  Treating with free oxygen-containing gas · CPC title