Back to results
US 6,694,774 B1Granted
Gas liquefaction method using natural gas and mixed gas refrigeration
AssigneePraxair Technology, Inc.
InventorsM. Abdul-Aziz Rashad, Richard C. Fitzgerald, Dante Patrick Bonaquist, John B. Saunders, Minish Mahendra Shah
Life of this patent
Estimating the term…
Abstract
A gas liquefaction method which uses the pressure energy of a natural gas processing system to generate refrigeration for high temperature cooling of a gas, and uses a mixed gas refrigerant fluid to generate refrigeration for low temperature cooling of the gas to produce liquefied product.
Claims17
A method for producing liquefied natural gas comprising:
- (A) cooling a first natural gas stream to produce first cooled natural gas, and expanding the first cooled natural gas to produce refrigeration bearing natural gas;
- (B) cooling a second natural gas stream by indirect heat exchange with the refrigeration bearing natural gas to produce second cooled natural gas;
- (C) compressing a mixed refrigerant fluid, cooling the compressed mixed refrigerant fluid, and expanding the cooled mixed refrigerant fluid to produce refrigeration bearing mixed refrigerant fluid;
- (D) warming the refrigeration bearing mixed refrigerant fluid by indirect heat exchange with the cooling compressed mixed refrigerant fluid and by indirect heat exchange with second cooled natural gas to condense at least some of the second cooled natural gas;
- and
- (E) recovering resulting condensed natural gas as product liquefied natural gas, wherein at least some of the power for compressing the mixed refrigerant fluid is provided from expanding the first cooled natural gas to produce the refrigeration bearing natural gas.
3 more elements
A method for producing liquefied natural gas comprising:
- (A) cooling a first natural gas stream to produce first cooled natural gas, and expanding the first cooled natural gas to produce refrigeration bearing natural gas;
- (B) cooling a second natural gas stream by indirect heat exchange with the refrigeration bearing natural gas to produce second cooled natural gas;
- (C) compressing a mixed refrigerant fluid, cooling the compressed mixed refrigerant fluid, and expanding the cooled mixed refrigerant fluid to produce refrigeration bearing mixed refrigerant fluid;
- (D) warming the refrigeration bearing mixed refrigerant fluid by indirect heat exchange with the cooling compressed mixed refrigerant fluid and by indirect heat exchange with second cooled natural gas to condense at least some of the second cooled natural gas;
- and
- (E) recovering resulting condensed natural gas as product liquefied natural gas, wherein the cooling of the first natural gas stream produces a vapor and a liquid fraction, and the vapor fraction is expanded to produce the refrigeration bearing natural gas.
3 more elements
A method for producing liquefied natural gas comprising:
- (A) cooling a first natural gas stream to produce first cooled natural gas, and expanding the first cooled natural gas to produce refrigeration bearing natural gas;
- (B) cooling a second natural gas stream by indirect heat exchange with the refrigeration bearing natural gas to produce second cooled natural gas;
- (C) compressing a mixed refrigerant fluid, cooling the compressed mixed refrigerant fluid, and expanding the cooled mixed refrigerant fluid to produce refrigeration bearing mixed refrigerant fluid;
- (D) warming the refrigeration bearing mixed refrigerant fluid by indirect heat exchange with the cooling compressed mixed refrigerant fluid and by indirect heat exchange with second cooled natural gas to condense at least some of the second cooled natural gas;
- and
- (E) recovering resulting condensed natural gas as product liquefied natural gas, wherein a portion of the second cooled natural gas is turboexpanded and then warmed to provide some cooling for at least one of the first natural gas stream, the second natural gas stream and the compressed mixed refrigerant fluid.
3 more elements
Dependencies are inferred from the claim text.