Refrigeration – Processes – Circulating external gas
Patent
1992-08-28
1993-10-12
Capossela, Ronald C.
Refrigeration
Processes
Circulating external gas
60 3912, 62 38, F25J 302
Patent
active
052514501
ABSTRACT:
The present invention is an improvement to a process for the cryogenic distillation of air to produce both nitrogen and oxygen products carried out in a single distillation column system wherein a feed air stream is distilled thereby producing a nitrogen overhead and a liquid oxygen bottoms. The improvement is characterized in that: (a) operating the single distillation column at a pressure between 70 and 300 psia [480 and 2,070 kPa.sub.(absolute) ]; (b) withdrawing a portion of the liquid oxygen bottoms having an oxygen concentration greater than 80% oxygen and preferably between 85% and 97% oxygen from the bottom of the single distillation column and reducing the pressure of and vaporizing the withdrawn liquid oxygen by heat exchange against a condensing nitrogen stream removed from a top section of the single distillation column; (c) feeding the condensed, nitrogen stream to a top section of the single distillation column as reflux; and (d) recovering the vaporized oxygen as at least a substantial portion of the oxygen product. The improvement can be further characterized by providing boilup by boiling at least another portion of the liquid oxygen bottoms by heat exchange against a condensing vapor stream, wherein the vapor stream to be condensed in an air stream at a higher pressure than the feed air stream or a recycle nitrogen stream at a pressure greater than the operating pressure of the single distillation column, or by recycling a portion of the oxygen product at a pressure of at least the operating pressure of the single distillation column to the bottom of the distillation column and/or by providing intermediate boilup to the stripping section of the single distillation column system by vaporizing a portion of descending column liquid by heat exchange against another condensing vapor stream, wherein the other vapor stream to be condensed is either an air stream at a higher pressure than the feed air stream or a recycle nitrogen stream at a pressure greater than the operating pressure of the single distillation column.
REFERENCES:
patent: 3210951 (1965-10-01), Gaumer
patent: 4224045 (1980-09-01), Olszewski et al.
patent: 4382366 (1983-05-01), Gaumer
patent: 4464188 (1984-08-01), Agrawal et al.
patent: 4702757 (1987-10-01), Kleinberg
patent: 4704148 (1987-11-01), Kleinberg
patent: 4707994 (1987-11-01), Shenoy et al.
patent: 4796431 (1989-01-01), Erickson
patent: 4936099 (1990-06-01), Woodward et al.
patent: 4947649 (1990-08-01), Agrawal et al.
patent: 5006139 (1991-04-01), Agrawal et al.
patent: 5049173 (1991-09-01), Cormier, Sr. et al.
Agrawal Rakesh
Xu Jianguo
Air Products and Chemicals Inc.
Capossela Ronald C.
Jones II Willard
Marsh William F.
Simmons James C.
LandOfFree
Efficient single column air separation cycle and its integration does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Efficient single column air separation cycle and its integration, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Efficient single column air separation cycle and its integration will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1896199