Praxair Technology, Inc.

Vijayaraghavan Srinivasan Chakravarthy

Maulik R Shelat

Henry Edward Howard

Michael James Lockett

Steven R Falta

Brian S Powell

Sang Muk Kwark

Dante Patrick Bonaquist

John Henri Royal

Richard John Jibb

James R Handley

Karl K Kibler

James R Dray

Nick Joseph Degenstein

M Mushtaq Ahmed

Bart Antonie Van Hassel

Hanfei Tuo

Michael J Lockhett

A system and method for recovery of rare gases such as neon, helium, xenon, and krypton in an air separation unit is provided. The rare gas recovery system comprises a non-condensable stripping column linked in a heat transfer relationship with a xenon-krypton column via an auxiliary condenser-reboiler. The non-condensable stripping column produces a rare gas containing overhead that is directed to the auxiliary condenser-reboiler where most of the neon is captured in a non-condensable vent stream that is further processed to produce a crude neon vapor stream that contains greater than about 50% mole fraction of neon with the overall neon recovery exceeding 95%. The xenon-krypton column further receives two streams of liquid oxygen from the lower pressure column and the rare gas containing overhead from the non-condensable stripping column and produces a crude xenon and krypton liquid stream and an oxygen-rich overhead.

System and method for recovery of non-condensable gases such as neon, helium, xenon, and krypton from an air separation unit

An argon reflux condensation system and method in which a plurality of once-through condensers are connected to an argon column of an air separation plant to condense argon-rich vapor streams for production of reflux to the argon column. Condensation of the argon-rich vapor streams is brought about through indirect heat exchange with crude liquid oxygen streams that partially vaporize and are introduced into a lower pressure column of the plant for further refinement. The flow rate of the crude liquid oxygen streams are sensed and controlled at locations in the air separation plant where the crude liquid oxygen is in a liquid state and in proportion to the size of the once-through heat exchangers. Prior to flowing into the once-through condensers, the partially vaporized crude oxygen stream enters a phase separator which separates the crude oxygen vapor from the crude liquid oxygen. The separated crude oxygen vapor bypasses the once-through condensers and is mixed with the vaporized oxygen stream that exits the one-through condensers. Feed stream flow rate to the argon column is controlled in response to air flow rate to the plant and product flow rate is controlled in response to the feed stream flow rate to the argon column.

Argon condensation system and method

An argon reflux condensation system and method in which a plurality of once-through heat exchangers are connected to an argon column of an air separation plant to condense argon-rich vapor streams for production of reflux to the argon column. Condensation of the argon-rich vapor streams is brought about through indirect heat exchange with crude liquid oxygen streams that partially vaporize and are introduced into a lower pressure column of the plant for further refinement. The flow rate of the crude liquid oxygen streams are sensed and controlled at locations in the plant where the crude liquid oxygen is in a liquid state and in proportion to the size of the once-through heat exchangers. Feed stream flow rate to the argon column is controlled in response to air flow rate to the plant and product flow rate is controlled in response to the feed stream flow rate to the argon column.

A system and method for the concurrent condensation of a nitrogen-rich vapor and vaporization of an oxygen-rich liquid in a distillation column based air separation unit is provided. The disclosed system includes a condenser-reboiler heat exchanger located between a lower pressure column and a higher pressure column and configured to condense a nitrogen-rich vapor from the higher pressure column and partially vaporize an oxygen-rich liquid from the lower pressure column. Within the condenser-reboiler heat exchanger, the nitrogen-rich vapor flows in an upward direction such that any non-condensables present in the nitrogen-rich vapor will accumulate proximate the upper portion or top of the condenser-reboiler modules where they can be easily removed through venting.

Condenser-reboiler system and method

A method and main heat exchange system for use in a cryogenic air separation plant in which down-flow and thermosiphon heat exchangers are employed to partially vaporize an oxygen-rich liquid produced in a lower pressure column and to condense the nitrogen-rich vapor in a higher pressure column. A greater proportion of the oxygen-rich liquid can be partially vaporized in the down-flow heat exchangers than in the thermosiphon heat exchangers and the nitrogen-rich vapor condensed in the thermosiphon heat exchangers can have a higher oxygen content than the nitrogen-rich vapor condensed in the down-flow heat exchangers. This allows the higher pressure column to operate at a lower pressure than would otherwise be possible. A central conduit can extend from the higher pressure column into the lower pressure column to introduce the nitrogen-rich vapor into at least the down-flow heat exchangers for purposes of reducing pressure drop and column height.

Main heat exchange system and method for reboiling

A condenser reboiler system located within a bottom region of a low pressure column of a double column arrangement that is used in an air separation system to separate air. The condenser reboiler system incorporates first and second heat exchangers of the down-flow type that are situated in a side-by-side relationship and with the first heat exchanger being shorter than the second heat exchanger so that the first heat exchanger will remain functional after a shut-down of the air separation system when the second heat exchanger(s) are not capable of operating due to liquid dumping into a sump region of the low pressure column. The side-by-side relationship allows the column to be fabricated without excessive height.

Down-flow condenser reboiler system for use in an air separation plant

A method of heating process streams fed to a boiler incorporating an oxygen transport membrane device that includes an oxygen-containing stream and a boiler feed water stream. The membrane device separates oxygen to support combustion of a fuel and generate heat to raise the steam. Heat is recovered and process streams are heated by separately heating portions of the oxygen-containing stream and the boiler feed water stream with a retentate stream produced from the oxygen separation and a flue gas stream generated from the combustion. The flow rate of the portion of the oxygen-containing stream heated by the retentate stream is greater than that heated by the flue gas stream to help minimize heat transfer area and thus, fabrication costs. Also, water is condensed from the flue gas stream during the heat exchange involved in the heat recovery to increase thermodynamic efficiency.

Method of heating boiler process feed streams

A cryogenic air separation system wherein nitrogen vapor from a higher pressure column and oxygen liquid from a lower pressure column each pass down through a once-through main condenser in heat exchange relation and some but not all of the oxygen liquid is vaporized such that the oxygen liquid and vapor exit the condenser in a liquid to vapor mass flowrate ratio within the range of from 0.05 to 0.5 whereby the need for a recirculation pump to ensure avoidance of oxygen boiling to dryness is eliminated.

Cryogenic air separation with once-through main condenser

A refrigeration system particularly useful with a multicomponent refrigerant fluid wherein the refrigerant fluid is cooled in an upward leg of a first vertically oriented heat exchanger section and further cooled in a downward leg of a second vertically oriented heat exchanger section prior to refrigeration generation and serial recycle flow through the two heat exchanger sections.

Growing community of inventors

Williamsville, NY, United States of America

Vijayaraghavan Srinivasan Chakravarthy