Natural gas liquid fractionation plant waste heat conversion to cooling capacity using kalina cycle

Patent metadata

Field	Value
Publication number	US-10487699-B2
Application number	US-201715842478-A
Country	US
Kind code	B2
Filing date	Dec 14, 2017
Priority date	Aug 8, 2017
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

Certain aspects of natural gas liquid fractionation plant waste heat conversion to cooling capacity using Kalina Cycle can be implemented as a system, which includes a waste heat recovery heat exchanger to heat a buffer fluid stream by exchange with a heat source in a natural gas liquid fractionation plant. The system includes a Kalina cycle energy conversion system including one or more first energy conversion heat exchangers to heat a first portion of a working fluid by exchange with the heated buffer fluid stream, a separator to receive the heated working fluid and to output a vapor stream of the working fluid and the liquid stream of the working fluid, and a cooling subsystem including a first cooling element to condense the vapor stream of the working fluid and a second cooling element configured to cool a process fluid stream from the natural gas liquid fractionation plant by exchange with the condensed vapor stream of the working fluid.

First claim

The invention claimed is:

1. A system comprising:
a waste heat recovery heat exchanger configured to heat a buffer fluid stream by exchange with a heat source in a natural gas liquid fractionation plant;
a Kalina cycle energy conversion system including:
one or more first energy conversion heat exchangers configured to heat a first portion of a working fluid by exchange with the heated buffer fluid stream;
a separator configured to receive the heated working fluid and to output a vapor stream of the working fluid and a liquid stream of the working fluid; and
a cooling subsystem including a first cooling element configured to condense the vapor stream of the working fluid and a second cooling element configured to cool a process fluid stream from the natural gas liquid fractionation plant by exchange with the condensed vapor stream of the working fluid.

2. The system of claim 1 , wherein the second cooling element is configured to cool ethane gas output from a deethanizer in the natural gas liquid fractionation plant.

3. The system of claim 1 , wherein the second cooling element comprises a chiller having a thermal duty of between 300 MM Btu/h and 500 MM Btu/h.

4. The system of claim 1 , wherein the first cooling element comprises a cooler having a thermal duty of between 400 Btu/h and 600 Btu/h.

5. The system of claim 1 , wherein the first cooling element comprises a valve.

6. The system of claim 1 , wherein the energy conversion system comprises a pump configured to pump the working fluid to a pressure of between 11 Bar and 12 Bar.

7. The system of claim 1 , wherein the one or more first energy conversion heat exchangers comprise:
an energy conversion heat exchanger having a thermal duty of between 100 MM Btu/h and 200 MM Btu/h; and
an energy conversion heat exchanger having a thermal duty of between 400 MM Btu/h and about 500 MM Btu/h.

8. The system of claim 1 , wherein the one or more first energy conversion heat exchangers are configured to heat a first portion of the working fluid, and wherein the Kalina cycle energy conversion system comprises one or more second energy conversion heat exchangers configured to heat a second portion of the working fluid, the second by exchange with the liquid stream of the working fluid.

9. The system of claim 8 , wherein the separator is configured to receive the heated first and second portions of the working fluid.

10. The system of claim 8 , wherein the one or more second energy conversion heat exchangers are configured to heat the second portion of the working fluid by exchange with the heated buffer fluid stream.

11. The system of claim 8 , wherein the one or more second energy conversion heat exchangers comprise:
a heat exchanger having a thermal duty of between 150 MM Btu/h and 250 MM Btu/h; and
a heat exchanger having a thermal duty of between 300 MM Btu/h and about 400 MM Btu/h.

12. The system of claim 1 , comprising a turbine configured to generate power from the liquid stream of the working fluid.

13. The system of claim 12 , wherein the second turbine comprises a high pressure recovery turbine.

14. The system of claim 1 , comprising a storage tank, wherein the buffer fluid stream flows from the storage tank, through the waste heat recovery heat exchanger, through the Kalina cycle energy conversion system, and back to the storage tank.

15. The system of claim 1 , wherein the waste heat recovery heat exchanger is configured to heat the buffer fluid stream by exchange with propane gas output from a propane dehydrator in the natural gas liquid fractionation plant.

16. The system of claim 1 , wherein the waste heat recovery heat exchanger is configured to heat the buffer fluid stream by exchange with a C5+ bottoms product from a debutanizer in the natural gas liquid fractionation plant.

17. The system of claim 1 , wherein the waste heat recovery heat exchanger is configured to heat the buffer fluid stream by exchange with butane gas output from a debutanizer in the natural gas liquid fractionation plant.

18. The system of claim 1 , wherein the waste heat recovery heat exchanger is configured to heat the buffer fluid stream by exchange with butane gas output from a butane dehydrator in the natural gas liquid fractionation plant.

19. The system of claim 1 , wherein the waste heat recovery heat exchanger is configured to heat the buffer fluid stream by exchange with pentane gas output from a depentanizer in the natural gas liquid fractionation plant.

20. The system of claim 1 , wherein the waste heat recovery exchanger is configured to heat the buffer fluid stream by exchange with acid gases output from an ADIP generator in the natural gas liquid fractionation plant.

21. The system of claim 1 , wherein the waste heat recovery exchanger is configured to heat the buffer fluid stream by exchange with lean ADIP output from an ADIP generator in the natural gas liquid fractionation plant.

22. The system of claim 1 , wherein the waste heat recovery exchanger is configured to heat the buffer fluid stream by exchange with light NG components output from a pre-flash drum in a decolorizing section of the natural gas liquid fractionation plant.

23. The system of claim 1 , wherein the waste heat recovery exchanger is configured to heat the buffer fluid stream by exchange with NG gas output from a decolorizer in the natural gas liquid fractionation plant.

24. The system of claim 1 , wherein the waste heat recovery exchanger is configured to heat the buffer fluid stream by exchange with compressed propane in the natural gas liquid fractionation plant.

25. The system of claim 1 , wherein the waste heat recovery exchanger is configured to heat the buffer fluid stream by exchange with dry ethane gas in the natural gas liquid fractionation plant.

26. The system of claim 1 , wherein the waste heat recovery exchanger is configured to heat the buffer fluid stream by exchange with pentane gas output from an RVP column in the natural gas liquid fractionation plant.

27. A method comprising:
heating a buffer fluid stream via a waste heat recovery heat exchanger by exchange with a heat source in a natural gas liquid fractionation plant;
generating power in a Kalina cycle energy conversion system, comprising:
heating a working fluid via one or more first energy conversion heat exchangers by exchange with the heated buffer fluid stream;
separating, in a separator, the heated working fluid into a vapor stream of the working fluid and a liquid stream of the working fluid;
condensing the vapor stream of the working fluid; and
cooling a process fluid stream in the natural gas liquid fractionation plant by exchange with the condensed vapor stream of the working fluid.

28. The method of claim 27 , wherein cooling the process fluid stream comprises producing at least 350 MM Btu/h of cooling capacity for the natural gas liquid fractionation plant.

29. The method of claim 27 , wherein cooling the process fluid stream comprises cooling ethane gas output from a deethanizer in the natural gas liquid fractionation plant.

30. The method of claim 27 , comprising pumping the working fluid to a pressure of between 11 Bar and 12 Bar.

31. The method of claim 27 , wherein heating the working fluid comprises heating the working fluid to a temperature of between 160° F. and 180° F.

Assignees

• Saudi Arabian Oil Co

Inventors

• Noureldin Mahmoud Bahy Mahmoud
• Kamel Akram Hamed Mohamed

Classifications

• F25J3/0242

  separation of CnHm with 3 carbon atoms or more · CPC title

• B01D3/146

  Multiple effect distillation · CPC title

• F01K25/10

  the vapours being cold, e.g. ammonia, carbon dioxide, ether · CPC title

• B01D3/065

  Multiple-effect flash distillation (more than two traps) · CPC title

• C10G7/00

  Distillation of hydrocarbon oils · CPC title