LNG storage tank vapor recovery by nitrogen cycle refrigeration with refrigeration make-up provided by separation of same vapor

Patent · Tue Dec 31 04:00:00 EST 1974

OSTI ID:6386032

Alleaume, J

Technigas's new technique for boiloff reliquefaction and nitrogen recovery uses the cold from some of the nitrogen vapors contained in the LNG boiloff to help reliquefy the methane and the remainder of the nitrogen. The liquid nitrogen used as a cold-producing fluid is extracted from boiloff from LNG cargo tanks or onshore storage tanks. The nitrogen extracted is free from the usual impurites which are present in other gases used to produce liquid nitrogen, and the refrigerating power needed to reliquefy boiloff is reduced. The boiloff is cryogenically distilled or fractionated by contact with a reflux liquid rich in nitrogen so as to obtain gaseous nitrogen and a nitrogen-free condensed hydrocarbon mixture which is then returned to the LNG tanks. The cold for the condenser of the distillation column is provided by the evaporation of the liquid nitrogen contained in a reservoir. The liquid-nitrogen vapors of the reservoir are mixed with the gaseous nitrogen extracted from the natural gas before being introduced into a nitrogen reliquefaction cycle.

• Assignee: Technigaz
• Patent Number(s): US 3857251
• OSTI ID: 6386032
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
035000 -- Natural Gas-- Storage-- (1989-)
42 ENGINEERING
420205* -- Engineering-- Transport & Storage Facilities-- (1980-)
ALKANES
CONTAINERS
COOLING
CRYOGENICS
ELEMENTS
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS FUELS
GASES
HYDROCARBONS
LIQUEFACTION
LIQUEFIED GASES
LIQUEFIED NATURAL GAS
METHANE
NATURAL GAS
NITROGEN
NONMETALS
ORGANIC COMPOUNDS
RECOVERY
REFRIGERATION
STORAGE FACILITIES
TANKS
THERMOCHEMICAL PROCESSES
VAPORS