Methods and apparatus for power recovery in fluid catalytic cracking systems

Patent metadata

Field	Value
Publication number	US-9702542-B2
Application number	US-201414520523-A
Country	US
Kind code	B2
Filing date	Oct 22, 2014
Priority date	Oct 22, 2014
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

A co-generation process for a regenerator in an FCC system having a reactor and a regenerator includes the steps of introducing flue gas from the regenerator into a heating unit at a first location of the heating unit, and introducing an oxygen/fuel gas mixture into the heating unit at a second location of the heating unit apart from the first location, and combusting the oxygen/fuel gas mixture in the heating unit at the second location to form a hot combustion gas. The process further includes the steps of combining the hot combustion gas and the flue gas at a third location of the heating unit apart from the first location to produce heated flue gas, heating water and/or steam with the heated flue gas to produce a heated steam, and introducing the heated steam into a turbine to extract energy from the heated steam.

First claim

What is claimed is:

1. A co-generation process for a regenerator in a fluidized catalytic cracking (FCC) system having a reactor and a regenerator, the process comprising the steps of:
introducing flue gas from the regenerator into a heating unit at a first location of the heating unit, and mixing air and fuel gas in the heating unit at a second location of the heating unit apart from the first location to provide an oxygen/fuel gas mixture;
combusting the oxygen/fuel gas mixture in the heating unit at the second location to form a hot combustion gas;
combining the hot combustion gas and the flue gas at a third location of the heating unit apart from the first location to produce heated flue gas;
heating water and/or steam with the heated flue gas to produce a heated steam; and
introducing the heated steam into a turbine to extract energy from the heated steam.

2. The process of claim 1 , wherein introducing the oxygen/fuel gas mixture comprises introducing an air/fuel gas mixture.

3. The process of claim 1 , further comprising expanding the heated flue gas prior to the step of heating the water and/or the stream with the heated flue gas.

4. The process of claim 1 , wherein combining the hot combustion gas and the flue gas at the third location comprises combining at a third location that is apart from the second location.

5. The process of claim 1 , wherein combining the hot combustion gas and the flue gas at the third location comprises combining at a third location that is coterminous with the second location.

6. The process of claim 1 , wherein producing the heated flue gas comprises producing a heated flue gas at a temperature of at least about 875° C.

7. The process of claim 1 , wherein producing the heated steam comprises producing a heated steam at a pressure of at least about 2.75 MPa.

8. The process of claim 1 , wherein introducing flue gas at the first location comprises annularly introducing the flue gas about the second location.

9. The process of claim 1 , wherein the fuel gas is derived from one or more of: natural gas, FCC dry gas, LPG, compressed PSA tail gas, and refinery fuel gas.

10. The process of claim 1 , wherein extracting energy from the heated steam comprises extracting electrical energy or mechanical energy.

11. A co-generation apparatus for a regenerator in a fluidized catalytic cracking (FCC) system having a reactor and a regenerator, the apparatus comprising:
a heating unit, in fluid communication with flue gas from the regenerator, that comprises first, second, and third locations, wherein the second and third locations are positioned apart from the first location, wherein the heating unit receives a flue gas from the regenerator at the first location, air and fuel gas is mixed in in the heating unit at the second location to provide an oxygen/fuel gas mixture which, when combusted forms a hot combustion gas, and wherein the heating unit combines the flue gas and the hot combustion gas at the third location to form a heated flue gas;
a water or steam source;
a heat exchanger in fluid communication with the heating unit and the water or steam source that heats the water or steam source with the heated flue gas stream to form a heated steam; and
a steam turbine in fluid communication with the heated steam from the heat exchanger, wherein the steam turbine is configured to generate energy upon entry of the heated steam therein.

12. The apparatus of claim 11 , wherein the second location is positioned apart from the third location.

13. The apparatus of claim 11 , wherein the second location is position coterminous with the third location.

14. The apparatus of claim 11 , wherein the heating unit is configured in a substantially Y-shaped configuration comprising first, second, and third ends, and wherein the first location is positioned at the first end, the second location is positioned at the second end, and the third location is positioned at the third end.

15. The apparatus of claim 11 , wherein the heating unit is substantially cylindrical or rectangular in configuration and comprises a first diameter and a second diameter that is greater than the first diameter, and a transition region between the first and second diameters, and wherein the first location is positioned in the first diameter, the second location is positioned in the transition region, and the third location is positioned in the second diameter.

16. The apparatus of claim 11 , wherein the heating unit is substantially cylindrical or rectangular in configuration, and wherein the first location is positioned about the second location.

17. The apparatus of claim 11 , further comprising an expander positioned between the heating unit and the heat exchanger and in fluid communication with both the heating unit and the heat exchanger for expanding the heated flue gas.

18. The apparatus of claim 11 , wherein the steam turbine is configured to generate mechanical or electrical energy.

19. The apparatus of claim 11 , wherein the fuel gas is derived from one or more of: natural gas, FCC dry gas, LPG, compressed PSA tail gas, and refinery fuel gas.

20. A co-generation process for a regenerator in a fluidized catalytic cracking (FCC) system having a reactor and a regenerator, the process comprising the steps of:
introducing flue gas from the regenerator into a combustion unit at a first location of the combustion unit, and mixing air and fuel gas in the combustion unit at a second location of the combustion unit apart from the first location to provide an air/fuel gas mixture;
combusting the air/fuel gas mixture in the combustion unit at the second location to form a hot combustion gas;
combining the hot combustion gas and the flue gas at a third location of the combustion unit apart from the first location to produce heated flue gas at a temperature of at least about 875° C.;
expanding the heated flue gas in an expander to form an expanded, heated flue gas, wherein the expander generates electrical energy;
heating water or steam with the expanded, heated flue gas to produce a heated steam at a pressure of at least about 2.75 MPa; and
introducing the heated steam into a turbine to extract energy in the form of mechanical or electrical energy from the heated steam.

Assignees

• Uop Llc

Inventors

• Victor Sanford Allan
• Johnson Ii Richard A
• Zhu Xin X

Classifications

• C10G11/182

  Regeneration · CPC title

• F05D2220/62

  with energy recovery turbines · CPC title

• F02C7/10

  by means of regenerative heat-exchangers · CPC title

• F02C1/06

  using reheated exhaust gas (F02C1/08 takes precedence) · CPC title

• Y02E20/16

  Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT] · CPC title