Dephlegmator process for nitrogen rejection from natural gas

Patent · Tue Mar 22 00:00:00 EST 1988

OSTI ID:5037535

Rowles, H C; Davis, R A

A process for the rejection of nitrogen from a pressurized natural gas feed stream containing nitrogen by cryogenic distillation is described comprising the steps of: (a) cooling the pressurized natural gas feed stream containing nitrogen whereby the stream partially condenses; (b) separating the feed stream into a liquid phase and a gaseous phase in a separator; (c) cooling the gaseous phase in a dephlegmator; (d) returning the methane enriched condensed portion to the separator in step (b); (e) cooling, condensing and expanding the nitrogen enriched non-condensed portion and feeding the cooled, condensed, expanded, nitrogen enriched portion to a low pressure distillation column as reflux; (f) subcooling the liquid phase of step (d) in the dephlegmator; (g) removing a first portion of a bottoms liquid from the bottom of the low pressure distillation column; (h) removing a second portion of the bottoms liquid from the bottom of the low pressure distillation column; and (i) removing an overhead vapor from the top of the low pressure distillation column, warming the overhead vapor thereby recovering refrigeration value from the overhead, and removing the warmed overhead vapor from the process as a nitrogen product.

• Assignee: Air Products and Chemicals, Inc., Allentown, PA
• Patent Number(s): US 4732598
• OSTI ID: 5037535
• Resource Relation: Patent File Date: Filed date 10 Nov 1986
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
NATURAL GAS
DENITRATION
NITROGEN
REMOVAL
COMPRESSED GASES
COOLING
CRYOGENICS
DISTILLATION
DISTILLATION EQUIPMENT
EVAPORATION
PRESSURIZING
REFRIGERATION
SEPARATION EQUIPMENT
CHEMICAL REACTIONS
ELEMENTS
ENERGY SOURCES
EQUIPMENT
FLUIDS
FOSSIL FUELS
FUEL GAS
FUELS
GAS FUELS
GASES
NONMETALS
PHASE TRANSFORMATIONS
SEPARATION PROCESSES
030300* - Natural Gas- Drilling
Production
& Processing