APPARATUS FOR THE LIQUEFACTION OF A GAS AND METHODS RELATING TO SAME

• US 20100186446A1
• Filed: 12/29/2009
• Published: 07/29/2010
• Est. Priority Date: 05/04/2001
• Status: Abandoned Application

• Current Assignee: Battelle Energy Alliance LLC (Battelle Memorial Institute)
• Original Assignee: Battelle Energy Alliance LLC (Battelle Memorial Institute)
• Inventors: McKellar, Michael G., Wilding, Bruce M., Turner, Terry D.
• Application Number:
  US12/648,659
• Publication Number:
  US 20100186446A1
• Time in Patent Office: Days
• US Class Current: 62/611
• CPC Class Codes: F25J 1/0022 Hydrocarbons, e.g. natural gas
• CPC Class Codes: F25J 1/0037 of a return stream
• CPC Class Codes: F25J 1/004 by flash gas recovery F25J1/0267 takes precedence
• CPC Class Codes: F25J 1/0045 by vaporising a liquid return stream
• CPC Class Codes: F25J 1/0052 by vaporising a liquid refrigerant stream
• CPC Class Codes: F25J 1/0202 in a quasi-closed internal refrigeration loop F25J1/0208, F25J1/0219, F25J1/0224 take precedence
• CPC Class Codes: F25J 1/0204 as a single flow SCR cycle
• CPC Class Codes: F25J 1/0232 integration within a pressure letdown station of a high pressure pipeline system
• CPC Class Codes: F25J 1/0245 Different modes, i.e. 'runs', of operation; Process control
• CPC Class Codes: F25J 1/0247 start-up of the process
• CPC Class Codes: F25J 1/0251 Intermittent or alternating process, so-called batch process, e.g. "peak-shaving"
• CPC Class Codes: F25J 1/0268 using a dedicated refrigeration means F25J1/0296 takes precedence
• CPC Class Codes: F25J 1/0269 Arrangement of liquefaction units or equipments fulfilling the same process step, e.g. multiple "trains" concept F25J1/0294 takes precedence
• CPC Class Codes: F25J 1/0275 adapted for special use of the liquefaction unit, e.g. portable or transportable devices
• CPC Class Codes: F25J 2205/20 using solidification of components
• CPC Class Codes: F25J 2205/84 using filter
• CPC Class Codes: F25J 2210/06 Splitting of the feed stream, e.g. for treating or cooling in different ways
• CPC Class Codes: F25J 2215/60 Methane
• CPC Class Codes: F25J 2220/62 Separating low boiling components, e.g. He, H2, N2, Air
• CPC Class Codes: F25J 2220/66 Separating acid gases, e.g. CO2, SO2, H2S or RSH
• CPC Class Codes: F25J 2230/30 : Compression of the feed stream
• CPC Class Codes: F25J 2230/32 : Compression of the product stream
• CPC Class Codes: F25J 2230/60 : the fluid being hydrocarbons or a mixture of hydrocarbons
• CPC Class Codes: F25J 2270/04 : Internal refrigeration with work-producing gas expansion loop
• CPC Class Codes: F25J 2270/90 : External refrigeration, e.g. conventional closed-loop mechanical refrigeration unit using Freon or NH3, unspecified external refrigeration
• CPC Class Codes: F25J 2280/02 : Control in general, load changes, different modes ("runs"), measurements
• CPC Class Codes: F25J 2280/10 : Control for or during start-up and cooling down of the installation
• CPC Class Codes: F25J 2280/30 : Control of a discontinuous or intermittent ("batch") process
• CPC Class Codes: F25J 2290/50 : Arrangement of multiple equipments fulfilling the same process step in parallel
• CPC Class Codes: F25J 2290/62 : Details of storing a fluid in a tank
• CPC Class Codes: F25J 3/08 : Separating gaseous impurities from gases or gaseous mixtures or from liquefied gases or liquefied gaseous mixturescold traps B01D8/00

Abstract

Apparatuses and methods are provided for producing liquefied gas, such as liquefied natural gas. In one embodiment, a liquefaction plant may be coupled to a source of unpurified natural gas, such as a natural gas pipeline at a pressure letdown station. A portion of the gas is drawn off and split into a process stream and a cooling stream. The cooling stream may sequentially pass through a compressor and an expander. The process stream may also pass through a compressor. The compressed process stream is cooled, such as by the expanded cooling stream. The cooled, compressed process stream is expanded to liquefy the natural gas. A gas-liquid separator separates the vapor from the liquid natural gas. A portion of the liquid gas may be used for additional cooling. Gas produced within the system may be recompressed for reintroduction into a receiving line.

Claims

1. A method of liquefying a gas, the method comprising:

liquefying at least a portion of a source gas to provide a liquid natural gas;

precipitating a solid within the liquid natural gas; and

separating the solid from the liquid natural gas.

2. The method of claim 1, further comprising subcooling the solid.

3. The method of claim 2, wherein precipitating a solid within the liquid natural gas comprises precipitating solid carbon dioxide within the liquid natural gas.

4. The method of claim 3, further comprising sublimating the solid carbon dioxide after separating the solid carbon dioxide from the liquid natural gas to form a gaseous carbon dioxide.

5. The method of claim 4, further comprising directing the gaseous carbon dioxide into a natural gas pipeline.

6. The method of claim 1, wherein liquefying at least a portion of the source gas to provide a liquid natural gas further comprises directing the source gas through at least one expansion valve.

7. The method of claim 1, further comprising bubbling and agitating the solid precipitate within the liquid natural gas.

8. The method of claim 1, wherein separating the solid from the liquid natural gas comprises directing a slurry comprising the solid and at least a portion of the liquid natural gas through a hydrocyclone.

9. A liquefaction plant comprising:

a product flow path defined and configured for delivery of a stream of gas through at least one expansion device and into a liquid-gas separator for producing a slurry of liquid natural gas and solid carbon dioxide from the at least a portion of a process stream within the liquid-gas separator; and

a hydrocyclone located and configured to receive a solid-liquid slurry from the liquid-gas separator.

10. The liquefaction plant of claim 9, further comprising a transfer tank located and configured to receive a solid-liquid slurry from the liquid-gas separator and deliver a solid-liquid slurry from the liquid-gas separator to the hydrocyclone.

11. The liquefaction plant of claim 10, further comprising an accumulator tank coupled to the transfer tank.

12. The liquefaction plant of claim 9, wherein the liquid-gas separator further comprises a gas bubbler.

13. The liquefaction plant of claim 9, further comprising a sublimation tank located and configured to receive and sublimate solid carbon dioxide from the hydrocyclone.

14. The liquefaction plant of claim 13, further comprising a compressor located and configured to compress carbon dioxide gas from the sublimation tank and direct compressed carbon dioxide gas into a natural gas pipeline.