Natural gas processing using supercritical fluid power cycles

Patent metadata

Field	Value
Publication number	US-11268754-B2
Application number	US-201816146506-A
Country	US
Kind code	B2
Filing date	Sep 28, 2018
Priority date	Sep 28, 2018
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

The systems and methods described herein integrate a supercritical fluid power generation system with a LNG production/NGL separation system. A heat exchanger thermally couples the supercritical fluid power generation system with the LNG production/NGL separation system. A relatively cool heat transfer medium, such as carbon dioxide, passes through the heat exchanger and cools a first portion of extracted natural gas. The relatively warm heat transfer medium returns to the supercritical fluid power generation system where a compressor and a thermal input device, such as a combustor, are used to increase the pressure and temperature of the heat transfer medium above its critical point to provide a supercritical heat transfer medium. A second portion of the extracted natural gas may be used as fuel for the thermal input device.

First claim

What is claimed:

1. A natural gas processing system, comprising:
a supercritical fluid power generation system to:
receive a thermal energy input;
provide a multiphase heat transfer medium comprising carbon dioxide at a temperature T 1 and a pressure P 1 ; and
generate a power output;

a LNG production/NGL separation system comprising a natural gas compression subsystem, a natural gas liquid subsystem, and a heat exchanger fluidly coupled to the supercritical fluid power generation system, the natural gas compression subsystem, and the natural gas liquid subsystem;

wherein:
the natural gas compression subsystem is to:
receive a first portion of extracted natural gas;
receive at least a portion of the power output from the supercritical fluid power generation system; and
provide the first portion of the extracted natural gas at a temperature T 2 and a pressure P 2 , wherein T 2 >T 1 ; and

the heat exchanger is to:
receive the first portion of the extracted natural gas at T 2 and P 2 from the natural gas compression subsystem;
receive the multiphase heat transfer medium at T 1 , P 1 from the supercritical fluid power generation system;
cool the first portion of the extracted natural gas at T 2 and P 2 with the multiphase heat transfer medium at T 1 , P 1 to produce extracted natural gas at a temperature T 3 and a pressure P 3 , wherein T 3 <T 2 ;
convey the first portion of extracted natural gas at T 3 , P 3 to a natural gas liquid subsystem of the LNG production/NGL separation system;
evaporate at least a portion of the multiphase heat transfer medium to provide a gaseous heat transfer medium at a temperature T 4 and a pressure P 4 , wherein T 4 >T 3 ; and
convey the gaseous heat transfer medium at T 4 , P 4 to the supercritical fluid power generation system; and

the natural gas liquid subsystem is to receive at least a least a portion of the power output from the supercritical fluid power generation system.

2. The natural gas processing system of claim 1 wherein the natural gas compression subsystem comprises a natural gas compressor to:
receive the first portion of the extracted natural gas at a temperature T 5 and a pressure P 5 ; and
increase the temperature and pressure of the first portion of the extracted natural gas at T 5 , P 5 to provide the first portion of the extracted natural gas at T 2 , P 2 , wherein T 2 >T 5 and P 2 >P 5 .

3. The natural gas processing system of claim 1 , wherein the natural gas liquid subsystem is further to condense the first portion of extracted natural gas at T 3 , P 3 to provide a liquefied natural gas (LNG) product at a temperature T 6 and a pressure P 6 .

4. The natural gas processing system of claim 3 , wherein the natural gas liquid subsystem is further to provide a natural gas liquid (NGL) product at a temperature T 7 and a pressure P 7 .

5. The natural gas processing system of claim 1 wherein the supercritical fluid power generation system further comprises:
a combustor to provide the thermal energy input, the combustor to:
combust a second portion of the extracted natural gas; and
provide a supercritical heat transfer medium at a temperature T 8 and a pressure P 8 .

6. The natural gas processing system of claim 5 wherein the supercritical fluid power generation system further comprises:
a turbine fluidly coupled to the combustor, the turbine to:
receive the supercritical heat transfer medium at T 8 P 8 ; and
expand the supercritical transfer medium at T 8 , P 8 to produce the power output and a gaseous thermal transfer medium at a temperature T 9 , P 9 ;

a first compressor to:
receive the gaseous heat transfer medium at T 4 , P 4 from the heat exchanger; and
compress the gaseous heat transfer medium at T 4 , P 4 to provide a gaseous heat transfer medium at a temperature T 10 and a pressure P 10 ;

a cooling system fluidly coupled to the first compressor and the turbine, the cooling system to:
receive at least a portion of the gaseous heat transfer medium at T 9 , P 9 and at least a portion of the gaseous heat transfer medium at T 10 , P 10 to produce a gaseous heat transfer medium at a temperature T 11 and a pressure P 11 ;

a second compressor fluidly coupled to the cooling system, the second compressor to:
receive the gaseous thermal transfer medium at T 11 , P 11 ; and
compress and cool the gaseous thermal transfer medium at T 11 , P 11 to provide a liquid thermal transfer medium at a temperature T 12 and a pressure P 12 ; and

an expansion valve to:
receive the liquid thermal transfer medium at T 12 , P 12 ; and
expand the at least a portion of the liquid thermal transfer medium at T 12 , P 12 to provide the multiphase heat transfer medium at T 1 , P 1 .

7. The natural gas processing system of claim 4 wherein the supercritical heat transfer fluid power generation system comprises a recuperated indirect-fired Brayton cycle recuperative power generation system.

8. The natural gas processing system of claim 4 wherein the supercritical heat transfer fluid power generation system comprises a direct-fired Brayton cycle power generation system.

9. The natural gas processing system of claim 8 wherein the Brayton cycle power generation system comprises a recuperated direct-fired Brayton cycle power generation system.

10. The natural gas processing system of claim 8 wherein the direct-fired Brayton cycle power generation system provides a blowdown at an eighth temperature and an eighth pressure.

11. The natural gas processing system of claim 1 wherein the heat exchanger comprises one or more microchannel heat exchangers.

Assignees

• Southwest Res Inst

Inventors

• Beck Griffin C
• Ransom David L
• Hoopes Kevin M

Classifications

• E21B23/0415

  using particular fluids, e.g. electro-active liquids · CPC title

• E21B23/0412

  characterised by pressure chambers, e.g. vacuum chambers · CPC title

• E21B47/0175

  Cooling arrangements · CPC title

• F25J1/0052

  by vaporising a liquid refrigerant stream · CPC title

• F25J1/0022 Primary

  Hydrocarbons, e.g. natural gas · CPC title