Organic Rankine cycle based conversion of gas processing plant waste heat into power

Patent metadata

Field	Value
Publication number	US-10995636-B2
Application number	US-201816165663-A
Country	US
Kind code	B2
Filing date	Oct 19, 2018
Priority date	Aug 24, 2015
Publication date	May 4, 2021
Grant date	May 4, 2021

Abstract

A system includes a waste heat recovery heat exchanger configured to heat a heating fluid stream by exchange with a heat source in a crude oil associated gas processing plant. The system includes an Organic Rankine cycle energy conversion system including a pump, an energy conversion heat exchanger configured to heat the working fluid by exchange with the heated heating fluid stream, a turbine and a generator configured to generate power by expansion of the heated working fluid, a cooling element configured to cool the expanded working fluid after power generation, and an accumulation tank. The heating fluid flows from the accumulation tank, through the waste heat recovery heat exchanger, through the Organic Rankine cycle energy conversion system, and back to the accumulation tank.

First claim

What is claimed is:

1. A system comprising:
a waste heat recovery heat exchanger positioned in a crude oil associated gas processing plant, the waste heat recovery heat exchanger configured to heat a heating fluid stream by exchange with a heat source in the crude oil associated gas processing plant;
an Organic Rankine cycle energy conversion system comprising:
an energy conversion heat exchanger configured to heat a working fluid by exchange with the heated heating fluid stream;
a turbine and a generator, wherein the turbine and generator are configured to generate power by expansion of the heated working fluid; and
a cooling element configured to cool the expanded working fluid after power generation;

wherein the crude oil associated gas processing plant is configured to process a hydrocarbon gas stream from a well to produce a sales gas comprising methane.

2. The system of claim 1 , wherein the energy conversion heat exchanger has a thermal duty of between 3000 MM Btu/h and 3500 MM Btu/h.

3. The system of claim 1 , wherein the energy conversion heat exchanger comprises an evaporator.

4. The system of claim 1 , wherein the energy conversion heat exchanger is configured to heat the working fluid to a temperature of between 150° F. and 160° F.

5. The system of claim 1 , wherein the energy conversion heat exchanger is configured to reduce the pressure of the working fluid to a pressure of between 10 Bar and 11 Bar.

6. The system of claim 1 , wherein the working fluid enters the turbine in a vapor phase.

7. The system of claim 1 , wherein the turbine and generator are configured to generate at least 60 MW of power.

8. The system of claim 1 , wherein the cooling element has a thermal duty of between 2500 MM Btu/h and 3000 MM Btu/h.

9. The system of claim 1 , wherein the cooling element is configured to cool the expanded working fluid by exchange with cooling fluid.

10. The system of claim 9 , wherein the amount of power generated by the turbine and generator varies based on the temperature of the cooling fluid.

11. The system of claim 10 , wherein when the temperature of the cooling fluid is less than 65° F., the turbine and generator generate between 70 MW and 90 MW of power.

12. The system of claim 10 , wherein when the temperature of the cooling fluid is at least 70° F., the turbine and generator generate between 60 MW and 80 MW of power.

13. The system of claim 1 , wherein the heat source comprises a vapor stream from a slug catcher of the gas processing plant.

14. The system of claim 1 , wherein the heat source comprises an output stream from a DGA stripper of the gas processing plant.

15. The system of claim 1 , wherein the heat source comprises one or more of a sweet gas stream and a sales gas stream of the gas processing plant.

16. The system of claim 1 , wherein the heat source comprises a propane header of a propane refrigeration unit of the gas processing plant.

17. The system of claim 1 , wherein the heat source comprises an output stream from a compressor of the gas processing plant.

18. A method comprising:
heating a heating fluid stream by exchange with a heat source in a crude oil associated gas processing plant, wherein the crude oil associated gas processing plant is configured to process a hydrocarbon gas stream from a well to produce a sales gas comprising methane; and
generating power in an Organic Rankine cycle energy conversion system, comprising:
heating a working fluid by exchange with the heated heating fluid stream;
generating power, by a turbine and generator, by expansion of the heated working fluid; and
cooling the expanded working fluid after power generation.

19. The method of claim 18 , comprising heating the working fluid to a temperature of between 150° F. and 160° F.

20. The method of claim 18 , wherein heating the working fluid comprises reducing the pressure of the working fluid to a pressure of between 10 Bar and 11 Bar.

21. The method of claim 18 , wherein generating power comprises generating at least 60 MW of power.

22. The method of claim 18 , wherein cooling the expanded working fluid comprises cooling the working fluid by exchange with cooling fluid.

23. The method of claim 22 , wherein the amount of power generated by the turbine and generator varies based on the temperature of the cooling fluid.

24. The method of claim 23 , wherein when the temperature of the cooling fluid is less than 65° F., the turbine and generator generate between 70 MW and 90 MW of power.

25. The method of claim 23 , wherein when the temperature of the cooling fluid is at least 70° F., the turbine and generator generate between 60 MW and 80 MW of power.

26. The method of claim 18 , comprising heating the heating fluid stream by exchange with a vapor stream from a slug catcher of the gas processing plant.

27. The method of claim 18 , comprising heating the heating fluid stream by exchange with an output stream from a DGA stripper of the gas processing plant.

28. The method of claim 18 , comprising heating the heating fluid stream by exchange with one or more of a sweet gas stream and a sales gas stream of the gas processing plant.

29. The method of claim 18 , comprising heating the heating fluid stream by exchange with a propane header of a propane refrigeration unit of the gas processing plant.

30. The method of claim 18 , comprising heating the heating fluid stream by exchange with an output stream from a compressor of the gas processing plant.

Assignees

• Saudi Arabian Oil Co

Inventors

• Noureldin Mahmoud Bahy Mahmoud
• Kamel Akram Hamed Mohamed

Classifications

• F25J2205/60

  using adsorption on solid adsorbents, e.g. by temperature-swing adsorption [TSA] at the hot or cold end · CPC title

• F25J2270/12

  External refrigeration with liquid vaporising loop · CPC title

• F25J2260/02

  Integration in an installation for exchanging heat, e.g. for waste heat recovery · CPC title

• F25J2210/06

  Splitting of the feed stream, e.g. for treating or cooling in different ways · CPC title

• F25J3/061

  Natural gas or substitute natural gas · CPC title