Production of liquid nitrogen using liquefied natural gas as sole refrigerant

Patent · Tue Aug 18 04:00:00 EDT 1992

OSTI ID:6951087

Agrawal, R; Ayres, C L

This patent describes a process for the liquefaction of a nitrogen stream produced by a cryogenic air separation unit having at least one distillation column. It comprises compressing the nitrogen stream to a pressure of at least 350 psi in a multi-stage compressor wherein interstage cooling is provided by heat exchange against vaporizing liquefied natural gas; condensing the compressed nitrogen stream by heat exchange against vaporizing liquefied natural gas; reducing the pressure of the condensed, compressed nitrogen stream thereby producing a two phase nitrogen stream; phase separating the two phase nitrogen stream into a liquid nitrogen stream and a nitrogen vapor stream; and warming the nitrogen vapor stream to recover refrigeration.

• Assignee: Air Products and Chemicals, Inc., Allentown, PA (United States)
• Patent Number(s): US 5139547; A
• Application Number: PPN: US 7-691771
• OSTI ID: 6951087
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030400 -- Natural Gas-- Products & By-Products
032000 -- Natural Gas-- Transport
Handling
& Storage
661210* -- Cryogenics-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CRYOGENICS
ELEMENTS
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS FUELS
GASES
LIQUEFACTION
LIQUEFIED GASES
LIQUEFIED NATURAL GAS
NATURAL GAS
NITROGEN
NONMETALS
REFRIGERANTS
THERMOCHEMICAL PROCESSES
USES
WORKING FLUIDS