Method and apparatus for capturing and using heat generated by the production of light olefins

• US 20090203951A1
• Filed: 02/11/2008
• Published: 08/13/2009
• Est. Priority Date: 02/11/2008
• Status: Abandoned Application

• Current Assignee: Stone & Webster Process Technology, Inc. (Technip Energies NV)
• Original Assignee: Stone & Webster Process Technology, Inc. (Technip Energies NV)
• Inventors: Coyte, Lois, Keady, Ginger, Kurukchi, Sabah
• Application Number:
  US12/069,474
• Publication Number:
  US 20090203951A1
• Time in Patent Office: Days
• US Class Current: 585/648
• CPC Class Codes: B01D 3/007 Energy recuperation; Heat pumps
• CPC Class Codes: B01D 3/14 Fractional distillation or use of a fractionation or rectification column
• CPC Class Codes: C10G 11/00 Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils cracking in direct contact with molten metals or salts C10G9/34
• CPC Class Codes: C10G 7/12 Controlling or regulating

Abstract

A system and method for capturing the heat generated by the various types of catalytic cracking of heavy hydrocarbons feedstocks for the production of a light olefins and using the captured heat in the operation of a C3 stripper or propane-propylene fractionator.

Claims

1. A system for capturing and using heat generated during the catalytic cracking of heavy hydrocarbon feedstocks comprising:

at least one condenser or cooler associated with the catalytic cracking unit;

a closed water recirculation system comprising water that is indirectly heated by the at least one condenser or cooler and provides indirect heat to at least one reboiler for a C3 stripper or propane-propylene fractionator.

2. The system described in claim 1 wherein the light olefin feedstock is produced by a catalytic cracking unit.

3. The system described in claim 2 wherein the at least one condenser or cooler is a condenser or cooler for overhead vapors of a main fractionator of the catalytic cracking unit.

4. The system described in claim 2 wherein the at least one condenser or cooler is a condenser or cooler for an intermediate sidestream from a main fractionator of the catalytic cracking unit.

5. The system described in claim 2 wherein the at least one condenser or cooler is a condenser or cooler for an environmental scrubber or reactor for the catalytic cracking unit.

6. The system described in claim 1 wherein the at least one condenser or cooler is a low level heat condenser or cooler.

7. The system described in claim 1 wherein the closed water recirculation system comprises a bottoms reboiler for the propane-propylene fractionator.

8. The system as described in claim 7 wherein the water supplied as an indirect heat source for the bottoms reboiler to the propane-propylene fractionator is at a temperature ranging from about 80 to about 120°

C.

9. The system as described in claim 7 wherein the water exiting the bottoms reboiler for the propane-propylene fractionator is at a temperature ranging from about 50 to about 75°

C.

10. A method for capturing and using heat generated during the production of a light olefins comprising the following steps:

heating water in a closed water recirculation system with heat produced by at least one condenser and/or cooler apparatus employed in production of a light olefin feedstock;

pumping the heated water in the closed water recirculation system to a reboiler for a downstream C3 stripper or propane-propylene fractionator;

said heated water providing indirect heating for the reboiler of the C3 stripper or propane-propylene fractionator; and

returning the cooled water exiting the reboiler of the C3 stripper or propane-propylene fractionator in the closed water recirculation system from the C3 stripper or propane-propylene fractionator to the at least one condenser and/or cooler for reheating.

11. The method as defined in claim 10 wherein the light olefins are produced by a catalytic cracking unit.

12. The method described in claim 11 wherein the at least one condenser or cooler is a condenser or cooler for overhead vapors of a main fractionator of the catalytic cracking unit.

13. The method described in claim 11 wherein the at least one condenser or cooler is a condenser or cooler for an intermediate side stream of a main fractionator of the catalytic cracking unit.

14. The method described in claim 11 wherein the at least one condenser or cooler is a condenser or cooler for an environmental scrubber or reactor for treating the cracked gases from the catalytic cracking unit.

15. The method described in claim 10 wherein the at least one condenser or cooler is a low level heat condenser or cooler.

16. The method described in claim 10 wherein the closed water recirculation system comprises a bottoms reboiler for a propane-propylene fractionator.

17. The method described in claim 16 wherein the water to the bottoms reboiler is at a temperature ranging from about 80 to about 120°

C.

18. The method described in claim 16 wherein the cooled water exiting the bottoms reboiler is at a temperature ranging from about 50 to about 75°

C.