US20130239609A1 - Krypton xenon recovery from pipeline oxygen - Google Patents
Krypton xenon recovery from pipeline oxygen Download PDFInfo
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- US20130239609A1 US20130239609A1 US13/888,555 US201313888555A US2013239609A1 US 20130239609 A1 US20130239609 A1 US 20130239609A1 US 201313888555 A US201313888555 A US 201313888555A US 2013239609 A1 US2013239609 A1 US 2013239609A1
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04642—Recovering noble gases from air
- F25J3/04745—Krypton and/or Xenon
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04006—Providing pressurised feed air or process streams within or from the air fractionation unit
- F25J3/04078—Providing pressurised feed air or process streams within or from the air fractionation unit providing pressurized products by liquid compression and vaporisation with cold recovery, i.e. so-called internal compression
- F25J3/0409—Providing pressurised feed air or process streams within or from the air fractionation unit providing pressurized products by liquid compression and vaporisation with cold recovery, i.e. so-called internal compression of oxygen
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
- F25J3/04278—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using external refrigeration units, e.g. closed mechanical or regenerative refrigeration units
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04763—Start-up or control of the process; Details of the apparatus used
- F25J3/04866—Construction and layout of air fractionation equipments, e.g. valves, machines
- F25J3/04969—Retrofitting or revamping of an existing air fractionation unit
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2205/00—Processes or apparatus using other separation and/or other processing means
- F25J2205/30—Processes or apparatus using other separation and/or other processing means using a washing, e.g. "scrubbing" or bubble column for purification purposes
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2270/00—Refrigeration techniques used
- F25J2270/02—Internal refrigeration with liquid vaporising loop
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2270/00—Refrigeration techniques used
- F25J2270/12—External refrigeration with liquid vaporising loop
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2270/00—Refrigeration techniques used
- F25J2270/14—External refrigeration with work-producing gas expansion loop
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2270/00—Refrigeration techniques used
- F25J2270/42—Quasi-closed internal or closed external nitrogen refrigeration cycle
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2270/00—Refrigeration techniques used
- F25J2270/50—Quasi-closed internal or closed external oxygen refrigeration cycle
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2290/00—Other details not covered by groups F25J2200/00 - F25J2280/00
- F25J2290/60—Details about pipelines, i.e. network, for feed or product distribution
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J2290/00—Other details not covered by groups F25J2200/00 - F25J2280/00
- F25J2290/62—Details of storing a fluid in a tank
Definitions
- the present invention relates to a method and apparatus for producing a krypton-xenon-rich stream from oxygen flowing in an oxygen pipeline that can be further processed to produce krypton and xenon products. More particularly, the present invention relates to such a method in which an oxygen stream is removed from an oxygen pipeline and then introduced into a cryogenic rectification process that produces the krypton-xenon-rich stream from bottoms liquid within a distillation column.
- Krypton and xenon are rare gases that are used in a variety of industrial, commercial, and medical applications and are typically recovered from air. Air contains approximately 78.08 percent nitrogen, 20.95 percent oxygen and 0.93 percent argon, on a moisture-free basis. The remainder of the air contains carbon dioxide, heavier hydrocarbons and trace amounts of neon, helium, krypton, hydrogen and xenon. Typically, krypton is present in an amount of about 1.14 part per million by volume and xenon is present in an amount of about 0.087 parts per million by volume.
- Krypton and xenon are recovered from the air by cryogenic distillation that involves the steps of compressing, cooling the air and then rectifying the air in distillation column having high and low pressure columns operatively associated with one another in a heat transfer relationship so that an oxygen-rich column bottoms collects in the low pressure column that is used to condense a nitrogen-rich vapor overhead produced in the higher pressure column.
- the resulting liquid nitrogen is used to reflux both the high and the low pressure column.
- the krypton and xenon will collect in the oxygen produced in the low pressure column due to the fact that both the krypton and xenon have a lower volatility than oxygen.
- a liquid oxygen stream, removed from the low pressure column will initially be distilled in a distillation column to produce a krypton-xenon-rich stream that can be further processed through a series of distillation steps to produce krypton and xenon products. In such further processing, heavier hydrocarbons that will also collect in the oxygen are removed.
- the distillation column used in connection with the initial concentrating of the krypton and xenon from the liquid oxygen stream is generally integrated into the air separation plant itself.
- An example of this is shown in U.S. Pat. No. 6,378,333 in which a liquid oxygen stream is removed from the low pressure column and then introduced into the top of a distillation column used to concentrate xenon in a bottoms liquid formed within such column.
- the distillation column is reboiled with nitrogen-rich vapor from the high pressure column that is in turn condensed to serve as reflux to the high pressure column. A portion of the bottoms liquid can be removed, sent to a trap to remove hydrocarbons and then reintroduced into the distillation column.
- a liquid oxygen stream is removed from the low pressure column and pumped to produce a pressurized liquid oxygen stream.
- Part of the pumped liquid oxygen stream is partially heated in a heat exchanger and vaporized.
- the resulting high pressure oxygen vapor is rectified in a distillation column that is refluxed with a remaining part of the pumped liquid oxygen stream.
- the heat exchanger is used to condense a compressed air stream that, after condensation, is fed into the double column unit. Part of the compressed air can be used to reboil the distillation column.
- a stream of crude liquid oxygen derived from bottoms liquid produced in the high pressure column is further refined in an auxiliary distillation column that is reboiled by an argon condenser to condense argon for reflux purposes within an argon column.
- the residual liquid from the auxiliary distillation column is taken as the krypton-xenon-rich stream.
- the present invention solves this problem by providing a process for the production of a krypton-xenon-rich stream that can be effectuated in a free standing apparatus that utilizes oxygen flowing from the plant in an oxygen pipeline.
- the present invention provides a method of producing a krypton-xenon-rich stream in which a pipeline oxygen stream, containing oxygen vapor, is removed from an oxygen pipeline at ambient temperature.
- the pipeline oxygen stream is introduced into a cryogenic rectification process to produce the krypton-xenon-rich stream.
- the pipeline oxygen stream is cooled to a temperature at or near a dew point temperature of the oxygen vapor contained in the pipeline oxygen stream.
- At least part of the pipeline oxygen stream, after having been cooled, is rectified in a distillation column to produce a krypton-xenon-rich liquid column bottoms.
- the krypton-xenon-rich stream is discharged from the distillation column and the krypton-xenon-rich stream composed of the krypton-xenon-rich liquid column bottoms. Refrigeration is imparted into the cryogenic rectification process.
- the pipeline oxygen stream can be cooled in a main heat exchanger and the rectification of the pipeline oxygen stream produces an oxygen-rich vapor column overhead.
- An oxygen-rich vapor stream composed of the oxygen-rich vapor column overhead, is removed from the distillation column and divided into a first oxygen-rich vapor stream and a second oxygen-rich vapor stream.
- the first oxygen-rich vapor stream is condensed in a condenser to produce a reflux stream and at least part of the reflux stream is introduced into the distillation column as reflux.
- the second oxygen-rich vapor stream is passed in indirect heat exchange with the pipeline oxygen stream from the oxygen pipeline in the main heat exchanger to assist in the cooling of the pipeline oxygen stream.
- the second oxygen-rich vapor stream is recycled back to the oxygen pipeline.
- a heat exchange stream can be compressed and then cooled within the main heat exchanger.
- the heat exchange stream is condensed in a reboiler operatively associated with the distillation column to produce boil-up within the distillation column.
- the heat exchange stream after having been condensed, is reduced in pressure and vaporized in the condenser in indirect heat exchange with the first oxygen-rich vapor stream, thereby to condense the first oxygen-rich vapor stream.
- the heat exchange stream after having been vaporized, is partially warmed within the main heat exchanger and then expanded in a turboexpander to produce an exhaust stream and the turboexpander is coupled to a compressor used in compressing the heat exchange stream.
- the exhaust stream is fully warmed within the main heat exchanger to impart the refrigeration to the cryogenic rectification process and is recycled back to the compressor.
- a heat exchange stream can be cooled within the main heat exchanger and then, condensed in a reboiler located within the distillation column to produce boil-up within the distillation column.
- the heat exchange stream after having been condensed, is vaporized in the condenser in indirect heat exchange with the first oxygen-rich vapor stream, thereby to condense the first oxygen-rich vapor stream and the heat exchange stream, after having been vaporized, is fully warmed within the main heat exchanger and then recycled back to the main heat exchanger.
- At least part of the reflux stream is introduced into the distillation column as part of the reflux thereof and an oxygen liquid stream is introduced into the distillation column to provide a further part of the reflux therefor and to impart the refrigeration into the cryogenic rectification process.
- the pipeline oxygen stream can be divided into a first oxygen vapor stream and a second oxygen vapor stream after having been cooled in the main heat exchanger.
- the first oxygen vapor stream can be expanded, introduced into the distillation column and rectified.
- the second oxygen vapor stream can be condensed in a reboiler operatively associated with the distillation column to produce boil-up for the distillation column and then expanded, after having been condensed and re-vaporized in the condenser in indirect heat exchange with the first oxygen-rich vapor stream.
- the second oxygen vapor stream, after having been re-vaporized, is fully warmed within the main heat exchanger, compressed and at least in part is recycled back into the oxygen pipeline.
- At least part of the reflux stream is passed into the distillation column as part of the reflux and an oxygen liquid stream is introduced into the distillation column as another part of the reflux and to introduce the refrigeration into the cryogenic rectification process.
- the pipeline oxygen stream can be divided into a first oxygen vapor stream and a second oxygen vapor stream.
- the first oxygen vapor stream is fully cooled within the main heat exchanger, introduced into the distillation column and rectified.
- the second oxygen vapor stream is compressed and fully cooled within the main heat exchanger and then condensed in a reboiler operatively associated with the distillation column to produce boil-up for the distillation column.
- the second oxygen vapor stream is expanded after having been condensed and re-vaporized in the condenser in indirect heat exchange with the first oxygen-rich vapor stream.
- the second oxygen vapor stream after having been re-vaporized, is fully warmed within the main heat exchanger, compressed and at least in part is recycled back into the oxygen pipeline.
- At least part of the reflux stream is passed into the distillation column as part of the reflux therefor and an oxygen liquid stream is passed into the column as another part of the reflux and to impart the refrigeration into the cryogenic rectification process.
- the reflux stream can be passed in indirect heat exchange with the oxygen liquid stream within a subcooler, thereby to subcool the reflux stream.
- the oxygen liquid stream after having passed through the subcooler, is expanded and introduced into the distillation column.
- a first part of the reflux stream after having been subcooled is passed into the distillation column as the part of the reflux therefore and a second part of the reflux stream, after having been subcooled, is discharged from the cryogenic rectification process.
- the present invention also relates to an apparatus for producing a krypton-xenon-rich stream.
- a cryogenic rectification plant is connected to an oxygen pipeline.
- the plant is configured to rectify a pipeline oxygen stream removed from an oxygen pipeline at ambient temperature and to produce the krypton-xenon-rich stream.
- the cryogenic rectification plant has a main heat exchanger connected to the oxygen pipeline so as to receive the pipeline oxygen stream and is configured to cool the pipeline oxygen stream to a temperature at or near a dew point temperature of oxygen vapor contained in the pipeline oxygen stream.
- a distillation column is connected to the main heat exchanger so as to receive at least part of the pipeline oxygen stream and is configured to rectify the at least part of the pipeline oxygen stream to produce a krypton-xenon-rich liquid column bottoms and an oxygen-rich vapor column overhead.
- the distillation column is provided with an outlet to discharge the krypton-xenon-rich stream from the distillation column such that the krypton-xenon-rich stream is composed of the krypton-xenon-rich liquid column bottoms.
- a condenser is connected to the distillation column so as to condense a first oxygen-rich vapor stream composed of the oxygen-rich vapor column overhead and thereby form a reflux stream and to return at least part of the reflux stream to the distillation column as reflux.
- the distillation column is also connected to the main heat exchanger so that a second oxygen-rich vapor stream, composed of the oxygen-rich vapor column overhead, is passed in indirect heat exchange with the pipeline oxygen stream from the oxygen pipeline to assist in the cooling of the pipeline oxygen stream.
- the main heat exchanger is also connected to the oxygen pipeline so that the second oxygen-rich vapor stream is recycled back to the oxygen pipeline.
- a means for imparting refrigeration to the cryogenic rectification plant is also provided.
- a compressor can be provided to compress a heat exchange stream and the main heat exchanger is connected to the compressor to receive the heat exchange stream, after having been compressed and then to cool the heat exchange stream.
- a reboiler is operatively associated with the distillation column to produce boil-up within the distillation column and is connected to the main heat exchanger so as to receive the heat exchange stream and to condense the heat exchange stream.
- the condenser is connected to the reboiler and is configured to vaporize the heat exchange stream, after having been condensed, through indirect heat exchange with the first oxygen-rich vapor stream, thereby to condense the first oxygen-rich vapor stream.
- the main heat exchanger is connected to the condenser and configured to receive the heat exchange stream after having been vaporized and to partially warm the heat exchange stream.
- An expansion valve is positioned between the condenser and the reboiler to expand the heat exchange stream after having been condensed and the refrigeration imparting means comprises a turboexpander connected to the main heat exchanger to receive the heat exchange stream after having been partially warmed and to expand the heat exchange stream, thereby to produce an exhaust stream.
- the turboexpander is coupled to the compressor used in compressing the heat exchange stream and the main heat exchanger is also connected to the turboexpander and is configured to fully warm the exhaust stream within the main heat exchanger to impart the refrigeration to the cryogenic rectification plant.
- a recycle compressor is positioned between the compressor and the heat exchanger to raise the pressure and recycle the heat exchange stream back to the compressor.
- the main heat exchanger can be configured to cool a heat exchange stream.
- a reboiler is operatively associated with the distillation column to produce boil-up within the distillation column and is connected to the main heat exchanger so as to receive the heat exchange stream and to condense the heat exchange stream.
- the condenser is connected to the reboiler and configured to vaporize the heat exchange stream, after having been condensed, through indirect heat exchange with the first oxygen-rich vapor stream, thereby to condense the first oxygen-rich vapor stream.
- An expansion valve is positioned between the condenser and the reboiler to expand the heat exchange stream after having been condensed and the main heat exchanger is connected to the condenser and is configured to receive the heat exchange stream after having been vaporized and to fully warm the heat exchange stream.
- a recycle compressor is connected to the main heat exchanger to receive the heat exchange stream after having been fully warmed such that the heat exchange stream is raised in pressure and recycled back into the main heat exchanger to fully cool the heat exchange stream.
- the refrigeration imparting means comprises the distillation column having an inlet positioned to receive an oxygen liquid stream as another part of the reflux.
- the distillation column can be connected to the main heat exchanger such that a first oxygen vapor stream composed of part of the pipeline oxygen stream is introduced into the distillation column and rectified.
- a reboiler is operatively associated with the distillation column to produce boil-up for the distillation column and is connected to the main heat exchanger so that a second oxygen vapor stream composed of another part of the pipeline oxygen stream is introduced into the reboiler and condensed.
- the reboiler is connected to the condenser so that the second oxygen vapor stream is introduced into the condenser and is re-vaporized through indirect heat exchange with the first oxygen-rich vapor stream, thereby to condense the first oxygen-rich vapor stream.
- Expansion valves are positioned between the main heat exchanger and the distillation column so that the first oxygen vapor stream is expanded prior to being introduced into the distillation column and between the reboiler and the condenser so that the second oxygen vapor stream after having been condensed is expanded.
- a compressor is connected between the main heat exchanger and the oxygen pipeline so that the second oxygen vapor stream after having been fully warmed is compressed back to pipeline pressure and at least in part is recycled back into the oxygen pipeline.
- the refrigeration imparting means comprises the distillation column having an inlet positioned to receive an oxygen liquid stream as another part of the reflux.
- the main heat exchanger and a compressor are connected to the oxygen pipeline so that a first oxygen vapor stream composed of part of the pipeline oxygen stream fully cools within the main heat exchanger and a second oxygen vapor stream composed of another part of the pipeline oxygen stream is compressed in the compressor and fully cools within the main heat exchanger.
- a reboiler is operatively associated with the distillation column to produce boil-up for the distillation column is connected to the main heat exchanger so that the second oxygen vapor stream is condensed in the reboiler.
- the condenser is connected to the reboiler so that the second oxygen vapor stream is re-vaporized after having been condensed through indirect heat exchange with the first oxygen-rich vapor stream.
- An expansion valve is positioned between the condenser and the reboiler to valve expand the second oxygen vapor stream after having been condensed in the reboiler.
- the main heat exchanger is connected to the condenser so that the second oxygen vapor stream is fully warmed within the main heat exchanger after having been re-vaporized.
- Another compressor is positioned between the main heat exchanger and the oxygen pipeline to compress the second oxygen vapor stream back to pipeline pressure and at least in part recycle the second oxygen vapor stream back into the oxygen pipeline.
- the refrigeration imparting means comprises the distillation column having an inlet positioned to receive an oxygen liquid stream as another part of the reflux.
- the condenser can be connected to the distillation column so that a first part of the reflux stream is introduced into the distillation column as part of the reflux thereof.
- a subcooler can be connected to the condenser.
- the subcooler is configured to receive the reflux stream and the oxygen liquid stream so that the reflux stream is subcooled within the subcooler.
- the subcooler is connected to the distillation column so that the oxygen liquid stream is introduced into the distillation column after having passed through the subcooler, a first part of the reflux stream is introduced into the distillation column and a second part of the reflux stream is discharged from the cryogenic rectification plant.
- a further expansion valve is positioned between the subcooler and the distillation column so that the oxygen liquid stream is valve expanded before introduction into the distillation column.
- FIG. 1 is a schematic process flow diagram of an apparatus designed to carry out a method in accordance with the present invention
- FIG. 2 is a schematic process flow diagram of an alternative embodiment of the apparatus illustrated in FIG. 1 ;
- FIG. 3 is a schematic process flow diagram of a further alternative embodiment of an apparatus designed to carry out a method in accordance with the present invention.
- FIG. 4 is a schematic process flow diagram of an alternative embodiment of the apparatus illustrated in FIG. 3 .
- a cryogenic rectification plant 1 is illustrated that is designed to process oxygen vapor flowing through an oxygen pipeline 2 and thereby produce a krypton-xenon-rich stream 3 that can be further processed to produce krypton and xenon products.
- Typical compositions of the stream flowing through oxygen pipeline 2 are as follows: Oxygen: 0.9950-0.9995; Argon: 0.0050-0.0005; Nitrogen: 0.0; Krypton: 1.6-6.1 ppm; and Xenon: 0.12-0.46 ppm.
- Krypton-xenon-rich stream 3 will have the following composition: Oxygen: 0.9950-0.9995; Argon: 0.0050-0.0005; Nitrogen: 0.0; Krypton: 150-2600 ppm; and Xenon: 100-400 ppm.
- Cryogenic rectification plant 1 would be constructed as a retrofit to an existing air separation plant installation in which oxygen produced by such plant is being routed to an application utilizing such oxygen by means of an oxygen pipeline 2 .
- An oxygen pipeline stream 10 is removed from the oxygen pipeline 2 at ambient temperature and is composed of the oxygen vapor flowing through the oxygen pipeline 2 .
- the oxygen pipeline stream 10 is introduced into a main heat exchanger 12 to cool the oxygen pipeline stream 10 to a temperature at or near its dewpoint.
- Main heat exchanger 12 can be of known braised aluminum plate-fin construction.
- distillation column 14 is provided with packing, either structured or random or a combination of the two type of packings or possibly sieve trays to contact an ascending vapor phase that becomes leaner in the krypton and xenon as it ascends and a descending liquid phase that become richer in the krypton and xenon as it descends such column.
- packing either structured or random or a combination of the two type of packings or possibly sieve trays to contact an ascending vapor phase that becomes leaner in the krypton and xenon as it ascends and a descending liquid phase that become richer in the krypton and xenon as it descends such column.
- Distillation column 14 is provided with an outlet 16 to discharge the krypton-xenon-rich stream 3 .
- a condenser 18 is connected to the top of distillation column 14 so as to condense a first oxygen-rich vapor stream 20 that is composed of the oxygen-rich vapor column overhead.
- the condensation produces a reflux stream 22 that as will be described is reintroduced, at least in part, into distillation column 14 as reflux.
- the distillation column 14 is also connected to the main heat exchanger 12 so that a second oxygen-rich vapor stream 24 passes in indirect heat exchange with the pipeline oxygen stream 10 to assist in the cooling of the pipeline oxygen stream 10 .
- the second oxygen-rich vapor stream 24 is then recycled back to the oxygen pipeline 2 as a warm stream 26 .
- the reflux stream 22 in its entirety could be introduced into the top of distillation column 24 , it can advantageously be subcooled in a subcooling unit 28 .
- a first part 30 of the reflux stream 22 is introduced into the top of distillation column 14 as part of the reflux for such column.
- a second part 32 of the reflux stream 22 is discharged from the subcooling unit 14 as a subcooled, krypton and xenon depleted liquid oxygen stream.
- the heat exchange duty of the subcooling unit 28 is provided by a liquid oxygen stream 34 that after passing through the subcooling unit 28 is expanded to the pressure of distillation column 14 in an expansion valve 36 and then introduced as a remaining part of the reflux for distillation column 14 .
- Liquid oxygen stream 34 can be obtained from the same installation where oxygen vapor is produced to feed oxygen pipeline 2 .
- liquid oxygen stream 34 is derived from a pumped stream that is later vaporized and fed into the oxygen pipeline 2 . As such, in the illustrated embodiments it is reduced in pressure to column pressure. However, if it were obtained at a lower pressure, expansion might not be necessary.
- the part 32 of the reflux stream 22 could be reintroduced into the air separation plant or possibly back to the oxygen pipeline 2 .
- the use of the liquid oxygen stream 34 is advantageous in that it allows the krypton and xenon within such liquid oxygen to be recovered and further, such stream also provides some of the refrigeration load of the cryogenic rectification plant 1 .
- Cryogenic rectification plant 1 is designed to be a free standing plant and as such is also designed to produce its own refrigeration. This is done in a heat pump loop that uses nitrogen or suitable fluid as the heat exchange fluid.
- a heat exchange stream 38 is compressed by a compressor 40 . After removal of the heat of compression by means of an aftercooler 42 , the heat exchange stream is cooled in the main heat exchanger 12 to produce a cooled heat exchange stream 44 .
- a reboiler 46 located in the bottom of the distillation column 14 is connected to the main heat exchanger 12 to receive the cooled heat exchange stream 44 and to produce boil up within the distillation column 14 and thereby initiate formation of the ascending vapor phase from vaporized krypton-xenon-rich liquid column bottoms.
- Condensed heat exchange stream 48 is then passed through an expansion valve 50 to cool such stream and thereby condense the first oxygen-rich vapor stream 20 .
- the term “partially warmed” in such context means warmed to a temperature between the warm and cold end temperature of the main heat exchanger 12 . The refrigeration is imparted by warming the exhaust stream 56 in the main heat exchanger 12 .
- the exhaust stream is then introduced into a recycle compressor 58 and after cooling within an aftercooler 60 is recirculated back to the compressor 40 as the heat exchanger stream 38 .
- a makeup for the heat exchange fluid can also be introduced as a makeup stream 62 to replace heat exchange fluid that is lost due to leakage.
- the compression of the heat exchange stream represents an energy outlay and cost. This energy cost can be reduced if part of the refrigeration requirement for the plant is provided by liquid oxygen stream 34 .
- cryogenic rectification plant 2 is illustrated that is an alternative embodiment of the cryogenic rectification plant 1 .
- cryogenic rectification plant 2 is not designed to be free-standing and hence, is not provided with a means to self-generate refrigeration. It does, however, employ a heat exchange loop in which heat exchange stream is cooled in a main heat exchanger 12 ′ that differs from main heat exchanger 12 in that it is not provided with passages to partially warm the re-vaporized heat exchange stream 52 .
- the resulting cool heat exchanger stream 44 is again introduced into reboiler 46 and condensed to produce a condensed heat exchange stream 48 ′ that, after passage through expansion valve 50 , is re-vaporized to produce the re-vaporized heat exchange stream 52 .
- the re-vaporized heat exchange stream 52 is warmed within the main heat exchanger 12 ′ to produce a warm heat exchange stream 64 that is reintroduced into the compressor 58 .
- the refrigeration is imparted into the cryogenic rectification plant solely by liquid oxygen stream 34 .
- liquid oxygen stream 34 could be introduced directly into distillation column 14 without subcooling the reflux stream 22 and the reflux stream could be introduced in its entirety into the distillation column 14 .
- cryogenic rectification plant 3 incorporates a cryogenic rectification plant 3 .
- Cryogenic rectification plant 3 as cryogenic rectification plant 2 , is not designed to be self-standing and as such is refrigerated externally by liquid oxygen stream 34 .
- the rectification is driven, however, not be a heat pump loop, but rather by the pipeline oxygen stream 10 .
- the oxygen produced in the air separation plant supplying oxygen pipeline 2 would be compressed or supplied at about 15 psi higher than the embodiments discussed above.
- Pipeline oxygen stream 10 is cooled in a main heat exchanger 12 ′′ that has fewer heat exchange passages than main heat exchangers 12 or 12 ′ given that it does not include a recycled heat exchange stream.
- the cooled pipeline oxygen stream is divided into a first oxygen vapor stream 70 and a second oxygen vapor stream 72 .
- First oxygen vapor stream 70 is valve expanded in an expansion valve 74 , introduced into the distillation column 14 and rectified.
- the second oxygen vapor stream 72 is introduced into reboiler 46 and condensed.
- the resulting condensed oxygen vapor stream 76 is then reduced in pressure by an expansion valve 78 and introduced into condenser 18 where it is re-vaporized in the production of the reflux.
- the reduction in pressure lowers the temperature of the condensed oxygen vapor stream 76 so that it can operate to condense reflux for the distillation column 14 .
- the reduction in pressure of the first oxygen vapor stream 70 lowers its temperature so that second oxygen vapor stream 72 can be condensed in reboiler 46 .
- the re-vaporized oxygen vapor stream 80 is warmed within main heat exchanger 12 ′′, compressed back to pipeline pressure in a compressor 82 . After removal of the heat of compression in an aftercooler 84 , a resulting first compressed oxygen vapor stream 86 is reintroduced into the oxygen pipeline 2 .
- a second compressed oxygen vapor stream 88 can be recycled back to the pipeline oxygen stream 10 given that such stream has a krypton and xenon content that can be recovered.
- FIG. 4 illustrates a cryogenic rectification plant 4 that is an alternative embodiment of the cryogenic rectification plant 3 .
- the pipeline oxygen stream 10 is divided into a first oxygen vapor stream 70 ′ and a second oxygen vapor stream 72 ′ prior to a main heat exchanger 12 ′′′.
- First oxygen vapor stream 70 ′ is cooled within main heat exchanger 12 ′′′ and then introduced into distillation column 14 for rectification.
- the second oxygen vapor stream 72 ′ is compressed by a compressor 90 and after removal of the heat of compression in an aftercooler 92 , is cooled, as a compressed oxygen vapor stream 94 .
- not all of the oxygen need be compressed to a higher pressure in order to drive the distillation as is the case in cryogenic rectification plant 3 .
- Compressed oxygen vapor stream 94 is introduced into reboiler 46 after cooling in main heat exchanger 12 ′′′ to form a condensed oxygen vapor stream 48 ′′.
- the condensed oxygen vapor stream 48 ′′ is re-vaporized within condenser 18 while condensing the reflux to form the revaporized oxygen vapor stream 80 .
- Cryogenic rectification plant 4 otherwise functions in the same manner as cryogenic rectification plant 3 .
- the krypton-xenon-rich stream 3 could be further processed on site and near any of the cryogenic rectification plants discussed above in order to lessen the amount of liquid that would be necessary to be transported for final processing to produce the krypton and xenon products. This would be done by vaporizing the krypton-xenon-rich stream and then subjecting such stream to catalytic oxidation followed by carbon dioxide and water vapor removal.
- the resulting dry stream would then be cooled and distilled in a distillation column equipped with enough stages to increase the concentration of krypton in the krypton-xenon-rich stream 3 from 340 ppm to 55 percent and that of xenon from 260 ppm to 43 percent with an oxygen impurity of 1 percent.
- the refrigeration requirement for such column could be provided by a portion of the condensed heat transfer fluid 48 .
- the following Table is a calculated example of the embodiment of the present invention illustrated in FIG. 1 illustrating a stream summary and heat and mass balance of the various streams flowing within cryogenic rectification plant 1 .
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Abstract
A method and apparatus for producing a krypton-xenon-rich stream in which a pipeline oxygen stream is removed from an oxygen pipeline at ambient temperature and then distilled in a cryogenic rectification plant to produce the krypton-xenon-rich stream from a column bottoms of a distillation column. The plant can generate its own refrigeration by way of a heat pump loop incorporating an expander or, alternatively, refrigeration can be added by means of a liquid oxygen reflux stream introduced into the top of such distillation column.
Description
- This application is a divisional of prior U.S. application Ser. No. 12/629,408, filed on Dec. 2, 2009.
- The present invention relates to a method and apparatus for producing a krypton-xenon-rich stream from oxygen flowing in an oxygen pipeline that can be further processed to produce krypton and xenon products. More particularly, the present invention relates to such a method in which an oxygen stream is removed from an oxygen pipeline and then introduced into a cryogenic rectification process that produces the krypton-xenon-rich stream from bottoms liquid within a distillation column.
- Krypton and xenon are rare gases that are used in a variety of industrial, commercial, and medical applications and are typically recovered from air. Air contains approximately 78.08 percent nitrogen, 20.95 percent oxygen and 0.93 percent argon, on a moisture-free basis. The remainder of the air contains carbon dioxide, heavier hydrocarbons and trace amounts of neon, helium, krypton, hydrogen and xenon. Typically, krypton is present in an amount of about 1.14 part per million by volume and xenon is present in an amount of about 0.087 parts per million by volume.
- Krypton and xenon are recovered from the air by cryogenic distillation that involves the steps of compressing, cooling the air and then rectifying the air in distillation column having high and low pressure columns operatively associated with one another in a heat transfer relationship so that an oxygen-rich column bottoms collects in the low pressure column that is used to condense a nitrogen-rich vapor overhead produced in the higher pressure column. The resulting liquid nitrogen is used to reflux both the high and the low pressure column. The krypton and xenon will collect in the oxygen produced in the low pressure column due to the fact that both the krypton and xenon have a lower volatility than oxygen. Consequently, a liquid oxygen stream, removed from the low pressure column will initially be distilled in a distillation column to produce a krypton-xenon-rich stream that can be further processed through a series of distillation steps to produce krypton and xenon products. In such further processing, heavier hydrocarbons that will also collect in the oxygen are removed.
- The distillation column used in connection with the initial concentrating of the krypton and xenon from the liquid oxygen stream is generally integrated into the air separation plant itself. An example of this is shown in U.S. Pat. No. 6,378,333 in which a liquid oxygen stream is removed from the low pressure column and then introduced into the top of a distillation column used to concentrate xenon in a bottoms liquid formed within such column. The distillation column is reboiled with nitrogen-rich vapor from the high pressure column that is in turn condensed to serve as reflux to the high pressure column. A portion of the bottoms liquid can be removed, sent to a trap to remove hydrocarbons and then reintroduced into the distillation column. In U.S. Pat. No. 6,694,775, a liquid oxygen stream is removed from the low pressure column and pumped to produce a pressurized liquid oxygen stream. Part of the pumped liquid oxygen stream is partially heated in a heat exchanger and vaporized. The resulting high pressure oxygen vapor is rectified in a distillation column that is refluxed with a remaining part of the pumped liquid oxygen stream. The heat exchanger is used to condense a compressed air stream that, after condensation, is fed into the double column unit. Part of the compressed air can be used to reboil the distillation column. In US Patent Appln. No. 2006/0021380 A1, unlike the other two patents, a stream of crude liquid oxygen derived from bottoms liquid produced in the high pressure column is further refined in an auxiliary distillation column that is reboiled by an argon condenser to condense argon for reflux purposes within an argon column. The residual liquid from the auxiliary distillation column is taken as the krypton-xenon-rich stream.
- The need for krypton and xenon has increased over time due to increased demands for the use of such gas in lighting and laser applications. Xenon is also used as an anesthetic. Thus, there also exists the need to retrofit cryogenic air separation plants to recover the krypton and xenon for such applications. The difficulty with such a retrofit is that it is difficult to modify an existing plant with apparatus such as set forth above.
- As will be discussed, the present invention solves this problem by providing a process for the production of a krypton-xenon-rich stream that can be effectuated in a free standing apparatus that utilizes oxygen flowing from the plant in an oxygen pipeline.
- The present invention provides a method of producing a krypton-xenon-rich stream in which a pipeline oxygen stream, containing oxygen vapor, is removed from an oxygen pipeline at ambient temperature. The pipeline oxygen stream is introduced into a cryogenic rectification process to produce the krypton-xenon-rich stream. In the cryogenic rectification process, the pipeline oxygen stream is cooled to a temperature at or near a dew point temperature of the oxygen vapor contained in the pipeline oxygen stream. At least part of the pipeline oxygen stream, after having been cooled, is rectified in a distillation column to produce a krypton-xenon-rich liquid column bottoms. The krypton-xenon-rich stream is discharged from the distillation column and the krypton-xenon-rich stream composed of the krypton-xenon-rich liquid column bottoms. Refrigeration is imparted into the cryogenic rectification process.
- The pipeline oxygen stream can be cooled in a main heat exchanger and the rectification of the pipeline oxygen stream produces an oxygen-rich vapor column overhead. An oxygen-rich vapor stream, composed of the oxygen-rich vapor column overhead, is removed from the distillation column and divided into a first oxygen-rich vapor stream and a second oxygen-rich vapor stream. The first oxygen-rich vapor stream is condensed in a condenser to produce a reflux stream and at least part of the reflux stream is introduced into the distillation column as reflux. The second oxygen-rich vapor stream is passed in indirect heat exchange with the pipeline oxygen stream from the oxygen pipeline in the main heat exchanger to assist in the cooling of the pipeline oxygen stream. The second oxygen-rich vapor stream is recycled back to the oxygen pipeline.
- A heat exchange stream can be compressed and then cooled within the main heat exchanger. The heat exchange stream is condensed in a reboiler operatively associated with the distillation column to produce boil-up within the distillation column. The heat exchange stream, after having been condensed, is reduced in pressure and vaporized in the condenser in indirect heat exchange with the first oxygen-rich vapor stream, thereby to condense the first oxygen-rich vapor stream. The heat exchange stream, after having been vaporized, is partially warmed within the main heat exchanger and then expanded in a turboexpander to produce an exhaust stream and the turboexpander is coupled to a compressor used in compressing the heat exchange stream. The exhaust stream is fully warmed within the main heat exchanger to impart the refrigeration to the cryogenic rectification process and is recycled back to the compressor.
- In another embodiment, a heat exchange stream can be cooled within the main heat exchanger and then, condensed in a reboiler located within the distillation column to produce boil-up within the distillation column. The heat exchange stream, after having been condensed, is vaporized in the condenser in indirect heat exchange with the first oxygen-rich vapor stream, thereby to condense the first oxygen-rich vapor stream and the heat exchange stream, after having been vaporized, is fully warmed within the main heat exchanger and then recycled back to the main heat exchanger. At least part of the reflux stream is introduced into the distillation column as part of the reflux thereof and an oxygen liquid stream is introduced into the distillation column to provide a further part of the reflux therefor and to impart the refrigeration into the cryogenic rectification process.
- In another embodiment, the pipeline oxygen stream can be divided into a first oxygen vapor stream and a second oxygen vapor stream after having been cooled in the main heat exchanger. The first oxygen vapor stream can be expanded, introduced into the distillation column and rectified. The second oxygen vapor stream can be condensed in a reboiler operatively associated with the distillation column to produce boil-up for the distillation column and then expanded, after having been condensed and re-vaporized in the condenser in indirect heat exchange with the first oxygen-rich vapor stream. The second oxygen vapor stream, after having been re-vaporized, is fully warmed within the main heat exchanger, compressed and at least in part is recycled back into the oxygen pipeline. At least part of the reflux stream is passed into the distillation column as part of the reflux and an oxygen liquid stream is introduced into the distillation column as another part of the reflux and to introduce the refrigeration into the cryogenic rectification process. In yet another embodiment, the pipeline oxygen stream can be divided into a first oxygen vapor stream and a second oxygen vapor stream. The first oxygen vapor stream is fully cooled within the main heat exchanger, introduced into the distillation column and rectified. The second oxygen vapor stream is compressed and fully cooled within the main heat exchanger and then condensed in a reboiler operatively associated with the distillation column to produce boil-up for the distillation column. The second oxygen vapor stream is expanded after having been condensed and re-vaporized in the condenser in indirect heat exchange with the first oxygen-rich vapor stream. The second oxygen vapor stream, after having been re-vaporized, is fully warmed within the main heat exchanger, compressed and at least in part is recycled back into the oxygen pipeline. At least part of the reflux stream is passed into the distillation column as part of the reflux therefor and an oxygen liquid stream is passed into the column as another part of the reflux and to impart the refrigeration into the cryogenic rectification process.
- In any embodiment of the present invention, the reflux stream can be passed in indirect heat exchange with the oxygen liquid stream within a subcooler, thereby to subcool the reflux stream. The oxygen liquid stream, after having passed through the subcooler, is expanded and introduced into the distillation column. A first part of the reflux stream after having been subcooled is passed into the distillation column as the part of the reflux therefore and a second part of the reflux stream, after having been subcooled, is discharged from the cryogenic rectification process.
- The present invention also relates to an apparatus for producing a krypton-xenon-rich stream. In accordance with this aspect of the present invention, a cryogenic rectification plant is connected to an oxygen pipeline. The plant is configured to rectify a pipeline oxygen stream removed from an oxygen pipeline at ambient temperature and to produce the krypton-xenon-rich stream. The cryogenic rectification plant has a main heat exchanger connected to the oxygen pipeline so as to receive the pipeline oxygen stream and is configured to cool the pipeline oxygen stream to a temperature at or near a dew point temperature of oxygen vapor contained in the pipeline oxygen stream. A distillation column is connected to the main heat exchanger so as to receive at least part of the pipeline oxygen stream and is configured to rectify the at least part of the pipeline oxygen stream to produce a krypton-xenon-rich liquid column bottoms and an oxygen-rich vapor column overhead. The distillation column is provided with an outlet to discharge the krypton-xenon-rich stream from the distillation column such that the krypton-xenon-rich stream is composed of the krypton-xenon-rich liquid column bottoms. A condenser is connected to the distillation column so as to condense a first oxygen-rich vapor stream composed of the oxygen-rich vapor column overhead and thereby form a reflux stream and to return at least part of the reflux stream to the distillation column as reflux. The distillation column is also connected to the main heat exchanger so that a second oxygen-rich vapor stream, composed of the oxygen-rich vapor column overhead, is passed in indirect heat exchange with the pipeline oxygen stream from the oxygen pipeline to assist in the cooling of the pipeline oxygen stream. The main heat exchanger is also connected to the oxygen pipeline so that the second oxygen-rich vapor stream is recycled back to the oxygen pipeline. A means for imparting refrigeration to the cryogenic rectification plant is also provided.
- In one embodiment, a compressor can be provided to compress a heat exchange stream and the main heat exchanger is connected to the compressor to receive the heat exchange stream, after having been compressed and then to cool the heat exchange stream. A reboiler is operatively associated with the distillation column to produce boil-up within the distillation column and is connected to the main heat exchanger so as to receive the heat exchange stream and to condense the heat exchange stream. The condenser is connected to the reboiler and is configured to vaporize the heat exchange stream, after having been condensed, through indirect heat exchange with the first oxygen-rich vapor stream, thereby to condense the first oxygen-rich vapor stream. The main heat exchanger is connected to the condenser and configured to receive the heat exchange stream after having been vaporized and to partially warm the heat exchange stream. An expansion valve is positioned between the condenser and the reboiler to expand the heat exchange stream after having been condensed and the refrigeration imparting means comprises a turboexpander connected to the main heat exchanger to receive the heat exchange stream after having been partially warmed and to expand the heat exchange stream, thereby to produce an exhaust stream. The turboexpander is coupled to the compressor used in compressing the heat exchange stream and the main heat exchanger is also connected to the turboexpander and is configured to fully warm the exhaust stream within the main heat exchanger to impart the refrigeration to the cryogenic rectification plant. A recycle compressor is positioned between the compressor and the heat exchanger to raise the pressure and recycle the heat exchange stream back to the compressor.
- In another embodiment, the main heat exchanger can be configured to cool a heat exchange stream. A reboiler is operatively associated with the distillation column to produce boil-up within the distillation column and is connected to the main heat exchanger so as to receive the heat exchange stream and to condense the heat exchange stream. The condenser is connected to the reboiler and configured to vaporize the heat exchange stream, after having been condensed, through indirect heat exchange with the first oxygen-rich vapor stream, thereby to condense the first oxygen-rich vapor stream. An expansion valve is positioned between the condenser and the reboiler to expand the heat exchange stream after having been condensed and the main heat exchanger is connected to the condenser and is configured to receive the heat exchange stream after having been vaporized and to fully warm the heat exchange stream. A recycle compressor is connected to the main heat exchanger to receive the heat exchange stream after having been fully warmed such that the heat exchange stream is raised in pressure and recycled back into the main heat exchanger to fully cool the heat exchange stream. The refrigeration imparting means comprises the distillation column having an inlet positioned to receive an oxygen liquid stream as another part of the reflux.
- In another embodiment, the distillation column can be connected to the main heat exchanger such that a first oxygen vapor stream composed of part of the pipeline oxygen stream is introduced into the distillation column and rectified. A reboiler is operatively associated with the distillation column to produce boil-up for the distillation column and is connected to the main heat exchanger so that a second oxygen vapor stream composed of another part of the pipeline oxygen stream is introduced into the reboiler and condensed. The reboiler is connected to the condenser so that the second oxygen vapor stream is introduced into the condenser and is re-vaporized through indirect heat exchange with the first oxygen-rich vapor stream, thereby to condense the first oxygen-rich vapor stream. Expansion valves are positioned between the main heat exchanger and the distillation column so that the first oxygen vapor stream is expanded prior to being introduced into the distillation column and between the reboiler and the condenser so that the second oxygen vapor stream after having been condensed is expanded. A compressor is connected between the main heat exchanger and the oxygen pipeline so that the second oxygen vapor stream after having been fully warmed is compressed back to pipeline pressure and at least in part is recycled back into the oxygen pipeline. The refrigeration imparting means comprises the distillation column having an inlet positioned to receive an oxygen liquid stream as another part of the reflux.
- In yet another embodiment, the main heat exchanger and a compressor are connected to the oxygen pipeline so that a first oxygen vapor stream composed of part of the pipeline oxygen stream fully cools within the main heat exchanger and a second oxygen vapor stream composed of another part of the pipeline oxygen stream is compressed in the compressor and fully cools within the main heat exchanger. A reboiler is operatively associated with the distillation column to produce boil-up for the distillation column is connected to the main heat exchanger so that the second oxygen vapor stream is condensed in the reboiler. The condenser is connected to the reboiler so that the second oxygen vapor stream is re-vaporized after having been condensed through indirect heat exchange with the first oxygen-rich vapor stream. An expansion valve is positioned between the condenser and the reboiler to valve expand the second oxygen vapor stream after having been condensed in the reboiler. The main heat exchanger is connected to the condenser so that the second oxygen vapor stream is fully warmed within the main heat exchanger after having been re-vaporized. Another compressor is positioned between the main heat exchanger and the oxygen pipeline to compress the second oxygen vapor stream back to pipeline pressure and at least in part recycle the second oxygen vapor stream back into the oxygen pipeline. The refrigeration imparting means comprises the distillation column having an inlet positioned to receive an oxygen liquid stream as another part of the reflux. In such embodiment, the condenser can be connected to the distillation column so that a first part of the reflux stream is introduced into the distillation column as part of the reflux thereof.
- In any embodiment of the present invention, a subcooler can be connected to the condenser. The subcooler is configured to receive the reflux stream and the oxygen liquid stream so that the reflux stream is subcooled within the subcooler. The subcooler is connected to the distillation column so that the oxygen liquid stream is introduced into the distillation column after having passed through the subcooler, a first part of the reflux stream is introduced into the distillation column and a second part of the reflux stream is discharged from the cryogenic rectification plant. A further expansion valve is positioned between the subcooler and the distillation column so that the oxygen liquid stream is valve expanded before introduction into the distillation column.
- While the specification concludes with claims distinctly pointing out the subject matter that Applicants regard as their invention, it is believed that the invention will be better understood when taken in connection with the accompanying drawings in which:
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FIG. 1 is a schematic process flow diagram of an apparatus designed to carry out a method in accordance with the present invention; -
FIG. 2 is a schematic process flow diagram of an alternative embodiment of the apparatus illustrated inFIG. 1 ; -
FIG. 3 is a schematic process flow diagram of a further alternative embodiment of an apparatus designed to carry out a method in accordance with the present invention; and -
FIG. 4 is a schematic process flow diagram of an alternative embodiment of the apparatus illustrated inFIG. 3 . - In order to avoid needless repetition in the explanation of the various Figures, the same reference numbers are used for elements thereof having the same description.
- With reference to
FIG. 1 , a cryogenic rectification plant 1 is illustrated that is designed to process oxygen vapor flowing through anoxygen pipeline 2 and thereby produce a krypton-xenon-rich stream 3 that can be further processed to produce krypton and xenon products. Typical compositions of the stream flowing throughoxygen pipeline 2, on a percentile, volume basis are as follows: Oxygen: 0.9950-0.9995; Argon: 0.0050-0.0005; Nitrogen: 0.0; Krypton: 1.6-6.1 ppm; and Xenon: 0.12-0.46 ppm. Krypton-xenon-rich stream 3 will have the following composition: Oxygen: 0.9950-0.9995; Argon: 0.0050-0.0005; Nitrogen: 0.0; Krypton: 150-2600 ppm; and Xenon: 100-400 ppm. Cryogenic rectification plant 1 would be constructed as a retrofit to an existing air separation plant installation in which oxygen produced by such plant is being routed to an application utilizing such oxygen by means of anoxygen pipeline 2. - An
oxygen pipeline stream 10 is removed from theoxygen pipeline 2 at ambient temperature and is composed of the oxygen vapor flowing through theoxygen pipeline 2. Theoxygen pipeline stream 10 is introduced into amain heat exchanger 12 to cool theoxygen pipeline stream 10 to a temperature at or near its dewpoint.Main heat exchanger 12 can be of known braised aluminum plate-fin construction. - The resulting cooled
oxygen pipeline stream 10 is then introduced into adistillation column 14 for rectification. Although not illustrated,distillation column 14 is provided with packing, either structured or random or a combination of the two type of packings or possibly sieve trays to contact an ascending vapor phase that becomes leaner in the krypton and xenon as it ascends and a descending liquid phase that become richer in the krypton and xenon as it descends such column. As a result, a krypton-xenon-rich column bottoms is produced at the bottom ofdistillation column 14 and an oxygen-rich vapor column overhead. -
Distillation column 14 is provided with anoutlet 16 to discharge the krypton-xenon-rich stream 3. Acondenser 18 is connected to the top ofdistillation column 14 so as to condense a first oxygen-rich vapor stream 20 that is composed of the oxygen-rich vapor column overhead. The condensation produces areflux stream 22 that as will be described is reintroduced, at least in part, intodistillation column 14 as reflux. Thedistillation column 14 is also connected to themain heat exchanger 12 so that a second oxygen-rich vapor stream 24 passes in indirect heat exchange with thepipeline oxygen stream 10 to assist in the cooling of thepipeline oxygen stream 10. The second oxygen-rich vapor stream 24 is then recycled back to theoxygen pipeline 2 as awarm stream 26. - Although in cryogenic rectification plant 1, the
reflux stream 22 in its entirety could be introduced into the top ofdistillation column 24, it can advantageously be subcooled in asubcooling unit 28. Afirst part 30 of thereflux stream 22 is introduced into the top ofdistillation column 14 as part of the reflux for such column. Asecond part 32 of thereflux stream 22 is discharged from thesubcooling unit 14 as a subcooled, krypton and xenon depleted liquid oxygen stream. The heat exchange duty of thesubcooling unit 28 is provided by aliquid oxygen stream 34 that after passing through thesubcooling unit 28 is expanded to the pressure ofdistillation column 14 in anexpansion valve 36 and then introduced as a remaining part of the reflux fordistillation column 14. -
Liquid oxygen stream 34 can be obtained from the same installation where oxygen vapor is produced to feedoxygen pipeline 2. In this regard,liquid oxygen stream 34 is derived from a pumped stream that is later vaporized and fed into theoxygen pipeline 2. As such, in the illustrated embodiments it is reduced in pressure to column pressure. However, if it were obtained at a lower pressure, expansion might not be necessary. Thepart 32 of thereflux stream 22 could be reintroduced into the air separation plant or possibly back to theoxygen pipeline 2. While optional in the cryogenic rectification plant 1, the use of theliquid oxygen stream 34 is advantageous in that it allows the krypton and xenon within such liquid oxygen to be recovered and further, such stream also provides some of the refrigeration load of the cryogenic rectification plant 1. - Cryogenic rectification plant 1 is designed to be a free standing plant and as such is also designed to produce its own refrigeration. This is done in a heat pump loop that uses nitrogen or suitable fluid as the heat exchange fluid. A
heat exchange stream 38 is compressed by acompressor 40. After removal of the heat of compression by means of anaftercooler 42, the heat exchange stream is cooled in themain heat exchanger 12 to produce a cooledheat exchange stream 44. Areboiler 46 located in the bottom of thedistillation column 14 is connected to themain heat exchanger 12 to receive the cooledheat exchange stream 44 and to produce boil up within thedistillation column 14 and thereby initiate formation of the ascending vapor phase from vaporized krypton-xenon-rich liquid column bottoms. This condenses the cooledheat exchange stream 44 and thereby produces a condensedheat exchange stream 48. Condensedheat exchange stream 48 is then passed through anexpansion valve 50 to cool such stream and thereby condense the first oxygen-rich vapor stream 20. This re-vaporizes the heat exchange stream to produce a re-vaporizedheat exchange stream 52 that is partially warmed withinmain heat exchanger 12 and then introduced into aturboexpander 54 to produce anexhaust stream 56. As used herein and in the claims, the term “partially warmed” in such context means warmed to a temperature between the warm and cold end temperature of themain heat exchanger 12. The refrigeration is imparted by warming theexhaust stream 56 in themain heat exchanger 12. The exhaust stream is then introduced into arecycle compressor 58 and after cooling within anaftercooler 60 is recirculated back to thecompressor 40 as theheat exchanger stream 38. A makeup for the heat exchange fluid can also be introduced as amakeup stream 62 to replace heat exchange fluid that is lost due to leakage. As can be appreciated, the compression of the heat exchange stream represents an energy outlay and cost. This energy cost can be reduced if part of the refrigeration requirement for the plant is provided byliquid oxygen stream 34. - With reference to
FIG. 2 , acryogenic rectification plant 2 is illustrated that is an alternative embodiment of the cryogenic rectification plant 1. Unlike cryogenic rectification plant 1,cryogenic rectification plant 2 is not designed to be free-standing and hence, is not provided with a means to self-generate refrigeration. It does, however, employ a heat exchange loop in which heat exchange stream is cooled in amain heat exchanger 12′ that differs frommain heat exchanger 12 in that it is not provided with passages to partially warm the re-vaporizedheat exchange stream 52. The resulting coolheat exchanger stream 44 is again introduced intoreboiler 46 and condensed to produce a condensedheat exchange stream 48′ that, after passage throughexpansion valve 50, is re-vaporized to produce the re-vaporizedheat exchange stream 52. The re-vaporizedheat exchange stream 52 is warmed within themain heat exchanger 12′ to produce a warmheat exchange stream 64 that is reintroduced into thecompressor 58. The refrigeration is imparted into the cryogenic rectification plant solely byliquid oxygen stream 34. In this regard,liquid oxygen stream 34 could be introduced directly intodistillation column 14 without subcooling thereflux stream 22 and the reflux stream could be introduced in its entirety into thedistillation column 14. - With reference to
FIG. 3 , a yet further embodiment of the present invention is illustrated that incorporates acryogenic rectification plant 3.Cryogenic rectification plant 3, ascryogenic rectification plant 2, is not designed to be self-standing and as such is refrigerated externally byliquid oxygen stream 34. The rectification is driven, however, not be a heat pump loop, but rather by thepipeline oxygen stream 10. In this regard, the oxygen produced in the air separation plant supplyingoxygen pipeline 2 would be compressed or supplied at about 15 psi higher than the embodiments discussed above.Pipeline oxygen stream 10 is cooled in amain heat exchanger 12″ that has fewer heat exchange passages thanmain heat exchangers oxygen vapor stream 70 and a secondoxygen vapor stream 72. Firstoxygen vapor stream 70 is valve expanded in anexpansion valve 74, introduced into thedistillation column 14 and rectified. The secondoxygen vapor stream 72 is introduced intoreboiler 46 and condensed. The resulting condensedoxygen vapor stream 76 is then reduced in pressure by anexpansion valve 78 and introduced intocondenser 18 where it is re-vaporized in the production of the reflux. The reduction in pressure, lowers the temperature of the condensedoxygen vapor stream 76 so that it can operate to condense reflux for thedistillation column 14. In a like manner the reduction in pressure of the firstoxygen vapor stream 70 lowers its temperature so that secondoxygen vapor stream 72 can be condensed inreboiler 46. - The re-vaporized
oxygen vapor stream 80 is warmed withinmain heat exchanger 12″, compressed back to pipeline pressure in acompressor 82. After removal of the heat of compression in anaftercooler 84, a resulting first compressedoxygen vapor stream 86 is reintroduced into theoxygen pipeline 2. Optionally, a second compressedoxygen vapor stream 88 can be recycled back to thepipeline oxygen stream 10 given that such stream has a krypton and xenon content that can be recovered. -
FIG. 4 illustrates a cryogenic rectification plant 4 that is an alternative embodiment of thecryogenic rectification plant 3. In cryogenic rectification plant 4, thepipeline oxygen stream 10 is divided into a firstoxygen vapor stream 70′ and a secondoxygen vapor stream 72′ prior to amain heat exchanger 12′″. Firstoxygen vapor stream 70′ is cooled withinmain heat exchanger 12′″ and then introduced intodistillation column 14 for rectification. The secondoxygen vapor stream 72′ is compressed by acompressor 90 and after removal of the heat of compression in anaftercooler 92, is cooled, as a compressedoxygen vapor stream 94. As is apparent, in such embodiment not all of the oxygen need be compressed to a higher pressure in order to drive the distillation as is the case incryogenic rectification plant 3. - Compressed
oxygen vapor stream 94 is introduced intoreboiler 46 after cooling inmain heat exchanger 12′″ to form a condensedoxygen vapor stream 48″. The condensedoxygen vapor stream 48″ is re-vaporized withincondenser 18 while condensing the reflux to form the revaporizedoxygen vapor stream 80. Cryogenic rectification plant 4 otherwise functions in the same manner ascryogenic rectification plant 3. - In any of the embodiments illustrated above, the krypton-xenon-
rich stream 3 could be further processed on site and near any of the cryogenic rectification plants discussed above in order to lessen the amount of liquid that would be necessary to be transported for final processing to produce the krypton and xenon products. This would be done by vaporizing the krypton-xenon-rich stream and then subjecting such stream to catalytic oxidation followed by carbon dioxide and water vapor removal. The resulting dry stream would then be cooled and distilled in a distillation column equipped with enough stages to increase the concentration of krypton in the krypton-xenon-rich stream 3 from 340 ppm to 55 percent and that of xenon from 260 ppm to 43 percent with an oxygen impurity of 1 percent. The refrigeration requirement for such column could be provided by a portion of the condensedheat transfer fluid 48. - The following Table is a calculated example of the embodiment of the present invention illustrated in
FIG. 1 illustrating a stream summary and heat and mass balance of the various streams flowing within cryogenic rectification plant 1. -
TABLE Stream 101 102 24 20 30 Vapour 1 1 1 1 0 Fraction Temperature 310.0 122.0 120.9 120.9 104.8 [K] Pressure [psia] 159.7 157.2 157.2 157.2 156.2 Flow 1000 1000 999 51 7 [moles/hr] Enthalpy 115.7 −2417.7 −2436.8 −2436.8 −5200.5 [Btu/mol] Mole Frac 0 0 0 0 0 (Nitrogen) Mole Frac 0.00398 0.00398 0.00398 0.00398 0.00398 (Argon) Mole Frac 0.996 0.996 0.996 0.996 0.996 (Oxygen) Mole Frac 5.59E−06 5.59E−06 5.11E−06 5.11E−06 5.11E−06 (Krypton) Mole Frac 4.26E−07 4.26E−07 5.39E−08 5.39E−08 5.39E−08 (Xenon) Stream 32 34 38 44 48 52 Vapour 0 0 1 1 0 1 Fraction Temperature 104.8 93.7 310.0 124.0 122.4 119.0 [K] Pressure [psia] 156.2 159.7 253.0 412.0 412.0 299.50 Flow 44 44 96 96 96 96 [moles/hr] Enthalpy −5200.5 −5469.1 108.0 −2796.1 −3827.0 −2644.8 [Btu/mol] Mole Frac 0 0 1 1 1 1 (Nitrogen) Mole Frac 0.00398 0.00398 0 0 0 0 (Argon) Mole Frac 0.996 0.996 0 0 0 0 (Oxygen) Mole Frac 5.11E−06 5.59E−06 0 0 0 0 (Krypton) Mole Frac 5.39E−08 4.26E−07 0 0 0 0 (Xenon) Stream 523 564 565 3 Vapour 1 1 1 0 Fraction Temperature 195.0 126.4 304.3 121.0 [K] Pressure [psia] 296.5 50.0 46.0 158.0 Flow 96 96 96 1.5 [moles/hr] Enthalpy −1407.0 −2165.8 68.8 −4811.3 [Btu/mol] Mole Frac 1 1 1 0 (Nitrogen) Mole Frac 0 0 0 0.00193 (Argon) Mole Frac 0 0 0 0.9962 (Oxygen) Mole Frac 0 0 0 3.42E−04 (Krypton) Mole Frac 0 0 0 2.65E−04 (Xenon) 1Pipeline oxygen stream before main heat exchanger 12 2Pipeline oxygen stream after main heat exchanger 12 3Re-vaporized heat exchange stream 52 after partial warming within main heat exchanger 12 4Exhaust stream 56 prior to warming within main heat exchanger 12 5Exhaust stream 56 after warming within main heat exchanger 12 - While the present invention has been discussed with reference to preferred embodiments, as would occur to those skilled in the art, numerous changes and omission could be made in such embodiments without departing from the sprit and scope of the present invention as set forth in the appended claims.
Claims (4)
1. A method of producing a krypton-xenon-rich stream comprising:
removing a pipeline oxygen stream, containing oxygen vapor, from an oxygen pipeline at ambient temperature;
cooling the pipeline oxygen stream to a temperature at or near a dew point temperature of the oxygen vapor contained in the pipeline oxygen stream within a main heat exchanger of a cryogenic rectification plant and dividing the pipeline oxygen stream into a first oxygen vapor stream and a second oxygen vapor stream;
expanding the first oxygen vapor stream and rectifying the first oxygen vapor stream in a distillation column of the cryogenic rectification plant to produce a krypton-xenon-rich liquid column bottoms and an oxygen-rich vapor column overhead;
condensing the second oxygen vapor stream in a reboiler operatively associated with the distillation column to produce boil-up for the distillation column;
expanding and then re-vaporizing the second oxygen vapor stream, after having been condensed, in a condenser through indirect heat exchange a first oxygen-rich vapor stream, composed of the oxygen-rich vapor column overhead, thereby condensing the first oxygen-rich vapor stream to form a reflux stream;
fully warming the second oxygen vapor stream and a second oxygen-rich vapor stream composed of the oxygen-rich vapor column overhead, within the main heat exchanger, compressing the second oxygen vapor stream and recycling the second oxygen vapor stream, at least in part, back into the oxygen pipeline and recycling the second oxygen-rich vapor stream back into the oxygen pipeline after having been fully warmed;
passing at least part of the reflux stream into the distillation column as part of the reflux;
passing an oxygen liquid stream into the distillation column as another part of the reflux to introduce the refrigeration into the cryogenic rectification plant; and
discharging the krypton-xenon-rich stream from the distillation column, the krypton-xenon-rich stream composed of the krypton-xenon-rich liquid column bottoms.
2. The method of claim 1 , wherein:
the reflux stream is passed in indirect heat exchange with the oxygen liquid stream within a subcooler, thereby to subcool the reflux stream;
the oxygen liquid stream after having passed through the subcooler is expanded and introduced into the distillation column;
a first part of the reflux stream after having been subcooled is passed into the distillation column as the part of the reflux therefor; and
a second part of the reflux stream, after having been subcooled, is discharged from the cryogenic rectification process.
3. An apparatus for producing a krypton-xenon-rich stream comprising:
a cryogenic rectification plant connected to an oxygen pipeline and configured to rectify a pipeline oxygen stream removed from an oxygen pipeline at ambient temperature and to produce the krypton-xenon-rich stream;
said cryogenic rectification plant comprising:
a main heat exchanger connected to the oxygen pipeline so as to receive the pipeline oxygen stream, the main heat exchanger configured to cool the pipeline oxygen stream to a temperature at or near a dew point temperature of oxygen vapor contained in the pipeline oxygen stream;
a distillation column connected to the main heat exchanger so as to receive a first oxygen vapor stream composed of part of the pipeline oxygen stream, the distillation column configured to rectify the first oxygen vapor stream to produce a krypton-xenon-rich liquid column bottoms and an oxygen-rich vapor column overhead and having an outlet to discharge the krypton-xenon-rich stream from the distillation column such that the krypton-xenon-rich stream is composed of the krypton-xenon-rich liquid column bottoms and an inlet positioned to receive an oxygen liquid stream as part of the reflux, thereby to impart refrigeration into the cryogenic rectification plant;
a reboiler operatively associated with the distillation column to produce boil-up for the distillation column, the reboiler connected to the main heat exchanger so that a second oxygen vapor stream composed of another part of the pipeline oxygen stream is introduced into the reboiler and condensed;
a condenser connected to the distillation column and the reboiler so that a first oxygen-rich vapor stream, composed of the oxygen-rich vapor column overhead, is condensed through indirect heat exchange with the second oxygen vapor stream, thereby to form a reflux stream returned at least part to the distillation column as reflux and to re-vaporize the second oxygen vapor stream;
expansion valves positioned between the main heat exchanger and the distillation column so that the first oxygen vapor stream is expanded prior to being introduced into the distillation column and between the reboiler and the condenser so that the second oxygen vapor stream after having been condensed is expanded;
the main heat exchanger connected to: the condenser so that the second oxygen vapor stream after having been re-vaporized is fully warmed within the main heat exchanger; the distillation column so that a second oxygen-rich vapor stream, composed of the oxygen-rich vapor column overhead, is passed in indirect heat exchange with the pipeline oxygen stream from the oxygen pipeline to assist in the cooling of the pipeline oxygen stream; and the oxygen pipeline so that the second oxygen-rich vapor stream is recycled back to the oxygen pipeline; and
a compressor connected between the main heat exchanger and the oxygen pipeline so that the second oxygen vapor stream after having been fully warmed is compressed back to pipeline pressure and at least in part is recycled back into the oxygen pipeline.
4. The method of claim 3 , wherein;
a subcooler is connected to a condenser and is configured to receive the reflux stream and the oxygen liquid stream so that the reflux stream is subcooled within the subcooler;
the subcooler is connected to the distillation column so that the oxygen liquid stream is introduced into the distillation column after having passed through the subcooler, a first part of the reflux stream is introduced into the distillation column and a second part of the reflux stream is discharged from the cryogenic rectification plant; and
a further expansion valve is positioned between the subcooler and the distillation column so that the oxygen liquid stream is valve expanded before introduction into the distillation column.
Priority Applications (1)
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US13/888,555 US20130239609A1 (en) | 2009-12-02 | 2013-05-07 | Krypton xenon recovery from pipeline oxygen |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/629,408 US8484992B2 (en) | 2009-12-02 | 2009-12-02 | Krypton xenon recovery from pipeline oxygen |
US13/888,555 US20130239609A1 (en) | 2009-12-02 | 2013-05-07 | Krypton xenon recovery from pipeline oxygen |
Related Parent Applications (1)
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US12/629,408 Division US8484992B2 (en) | 2009-12-02 | 2009-12-02 | Krypton xenon recovery from pipeline oxygen |
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US20130239609A1 true US20130239609A1 (en) | 2013-09-19 |
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US12/629,408 Expired - Fee Related US8484992B2 (en) | 2009-12-02 | 2009-12-02 | Krypton xenon recovery from pipeline oxygen |
US13/888,555 Abandoned US20130239609A1 (en) | 2009-12-02 | 2013-05-07 | Krypton xenon recovery from pipeline oxygen |
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US12/629,408 Expired - Fee Related US8484992B2 (en) | 2009-12-02 | 2009-12-02 | Krypton xenon recovery from pipeline oxygen |
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US (2) | US8484992B2 (en) |
EP (1) | EP2507568A2 (en) |
CN (1) | CN103038589A (en) |
BR (1) | BR112012013079A2 (en) |
WO (1) | WO2011068634A2 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103968641A (en) * | 2014-05-19 | 2014-08-06 | 上海启元空分技术发展股份有限公司 | Method for controlling flow of gas entering krypton xenon rectifying tower |
US20150168058A1 (en) * | 2013-12-17 | 2015-06-18 | L'air Liquide, Societe Anonyme Pour I'etude Et I'exploitation Des Procedes Georges Claude | Apparatus for producing liquid nitrogen |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
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FR3074274B1 (en) * | 2017-11-29 | 2020-01-31 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | METHOD AND APPARATUS FOR AIR SEPARATION BY CRYOGENIC DISTILLATION |
CN108413707B (en) * | 2018-05-15 | 2023-12-22 | 瀚沫能源科技(上海)有限公司 | Krypton-xenon concentration and neon-helium concentration process integration system and method |
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- 2010-11-08 EP EP10779610A patent/EP2507568A2/en not_active Withdrawn
- 2010-11-08 CN CN2010800630294A patent/CN103038589A/en active Pending
- 2010-11-08 BR BR112012013079A patent/BR112012013079A2/en not_active IP Right Cessation
- 2010-11-08 WO PCT/US2010/055784 patent/WO2011068634A2/en active Application Filing
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- 2013-05-07 US US13/888,555 patent/US20130239609A1/en not_active Abandoned
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CN103968641A (en) * | 2014-05-19 | 2014-08-06 | 上海启元空分技术发展股份有限公司 | Method for controlling flow of gas entering krypton xenon rectifying tower |
Also Published As
Publication number | Publication date |
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WO2011068634A3 (en) | 2015-06-11 |
CN103038589A (en) | 2013-04-10 |
BR112012013079A2 (en) | 2016-11-22 |
US8484992B2 (en) | 2013-07-16 |
WO2011068634A2 (en) | 2011-06-09 |
US20110126585A1 (en) | 2011-06-02 |
EP2507568A2 (en) | 2012-10-10 |
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