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Nitrogen rejection fractionation system for variable nitrogen content natural gas

Patent ·
OSTI ID:6532461

A process is described for separating nitrogen from a pressurized feed containing natural gas and nitrogen over a wide concentration range of 5 to 85 volume percent nitrogen in a single distillation column. Two side intermediate condensers form pressurized product stream of nitrogen and natural gas. This process comprises: cooling and separating the pressurized feed into separate multiple feeds to the column and distilling the cooled feeds in the distillation column to form a pressurized overhead vapor rich in nitrogen and a pressurized bottoms liquid rich in natural gas hydrocarbons; condensing an overhead vapor of an upper section of the column by heat exchange with a first closed loop refrigerant to provide reflux to the column; and condensing in the upper of two side condensers an intermediate vapor from an intermediate section of the column.

Assignee:
Air Products and Chemicals, Inc., Allentown, PA
Patent Number(s):
US 4662919
OSTI ID:
6532461
Country of Publication:
United States
Language:
English