PROCESS AND APPARATUS FOR LIQUEFYING NATURAL GAS CONTAINING NITROGEN BY USING COOLED EXPANDED AND FLASHED GAS THEREFROM AS A COOLANT THEREFOR

• US 3,616,652 A
• Filed: 09/11/1967
• Issued: 11/02/1971
• Est. Priority Date: 09/27/1966
• Status: Expired due to Term

• Current Assignee: Manfred O. Engel
• Original Assignee: Manfred O. Engel
• Inventors: Engel, Manfred O.
• Application Number:
  US04/666,680
• Time in Patent Office: 1,513 Days
• US Class Current: 62/613
• CPC Class Codes: F25J 1/0022 Hydrocarbons, e.g. natural gas
• CPC Class Codes: F25J 1/0035 by gas expansion with extraction of work
• 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 1/0042 by liquid expansion with extraction of work
• 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 1/0247 start-up of the process
• CPC Class Codes: F25J 1/0264 Arrangement of heat exchanger cores in parallel with different functions, e.g. different cooling streams F25J1/0272 takes precedence
• CPC Class Codes: F25J 2210/06 Splitting of the feed stream, e.g. for treating or cooling in different ways
• CPC Class Codes: F25J 2230/30 Compression of the feed stream
• CPC Class Codes: F25J 2240/40 Expansion without extracting work, i.e. isenthalpic throttling, e.g. JT valve, regulating valve or venturi, or isentropic nozzle, e.g. Laval
• CPC Class Codes: F25J 2270/06 with multiple gas expansion loops

Abstract

A LIQUEFACTION PROCESS FOR NATURAL GAS WHICH THE GAS IS INITIALLY LIQUEFIED AT HIGH PRESSURE, THE LIQUID IS EXPANDED AND COOLED AND THEN FLASHED TO GIVE A LOW PRESSURE LIQUID AND FLASH GAS, AND THE FLASH GAS IS RECIRCULATED TO COOL THE INCOMING GAS AT VARIOUS STAGES OF THE PROCESS. THE RECIRCULATED FLASH GAS CAN BE COOLED BY COMPRESSION AND EXPANSION AND RE-INTRODUCED INTO THE SYSTEM AT VARIOUS POINTS INCLUDING THAT AT WHICH THE LIQUID GAS BEFORE FLASHING IS PRESENT.

Claims