EP0218740B1 - Verfahren zum Gewinnen eines Krypton-Xenonkonzentrats aus einer flüssigen Mischung - Google Patents

Verfahren zum Gewinnen eines Krypton-Xenonkonzentrats aus einer flüssigen Mischung Download PDF

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Publication number
EP0218740B1
EP0218740B1 EP85113013A EP85113013A EP0218740B1 EP 0218740 B1 EP0218740 B1 EP 0218740B1 EP 85113013 A EP85113013 A EP 85113013A EP 85113013 A EP85113013 A EP 85113013A EP 0218740 B1 EP0218740 B1 EP 0218740B1
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EP
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Prior art keywords
liquid
krypton
xenon
column
lean
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
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EP85113013A
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English (en)
French (fr)
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EP0218740A1 (de
Inventor
Harry Cheung
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Union Carbide Corp
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Union Carbide Corp
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Priority to US06/641,553 priority Critical patent/US4574006A/en
Application filed by Union Carbide Corp filed Critical Union Carbide Corp
Priority to DE8585113013T priority patent/DE3573307D1/de
Priority to EP85113013A priority patent/EP0218740B1/de
Priority to AT85113013T priority patent/ATE46761T1/de
Publication of EP0218740A1 publication Critical patent/EP0218740A1/de
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Publication of EP0218740B1 publication Critical patent/EP0218740B1/de
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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
    • F25J3/04406—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 using a dual pressure main column system
    • F25J3/04412—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 using a dual pressure main column system in a classical double column flowsheet, i.e. with thermal coupling by a main reboiler-condenser in the bottom of low pressure respectively top of high pressure column
    • 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
    • F25J3/04333—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using quasi-closed loop internal vapor compression refrigeration cycles, e.g. of intermediate or oxygen enriched (waste-)streams
    • F25J3/04363—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using quasi-closed loop internal vapor compression refrigeration cycles, e.g. of intermediate or oxygen enriched (waste-)streams of oxygen
    • 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
    • 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
    • F25J3/04951—Arrangements of multiple air fractionation units or multiple equipments fulfilling the same process step, e.g. multiple trains in a network
    • F25J3/04963—Arrangements of multiple air fractionation units or multiple equipments fulfilling the same process step, e.g. multiple trains in a network and inter-connecting equipment within or downstream of the fractionation unit(s)
    • 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
    • F25J2200/00—Processes or apparatus using separation by rectification
    • F25J2200/34—Processes or apparatus using separation by rectification using a side column fed by a stream from the low pressure column
    • 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
    • F25J2200/00—Processes or apparatus using separation by rectification
    • F25J2200/40—Features relating to the provision of boil-up in the bottom of a column
    • 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
    • F25J2200/00—Processes or apparatus using separation by rectification
    • F25J2200/76—Refluxing the column with condensed overhead gas being cycled in a quasi-closed loop refrigeration cycle
    • 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
    • F25J2200/00—Processes or apparatus using separation by rectification
    • F25J2200/90—Details relating to column internals, e.g. structured packing, gas or liquid distribution
    • F25J2200/94—Details relating to the withdrawal point
    • 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
    • F25J2235/00—Processes or apparatus involving steps for increasing the pressure or for conveying of liquid process streams
    • F25J2235/50—Processes or apparatus involving steps for increasing the pressure or for conveying of liquid process streams the fluid being oxygen
    • 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

  • This invention relates to the production of a krypton-xenon concentrate from a liquid feed and is an improvement whereby the concentrate is produced at high efficiency and a rare gas depleted liquid is recovered as product.
  • Krypton and xenon are undergoing increasing demand in a number of applications.
  • Krypton is being widely used in high quantity lighting including long-life light bulbs and automotive lamps.
  • Xenon is being used for medical applications including special x-ray equipment. Both of these gases are commonly used in many laboratory and research applications.
  • krypton and xenon The principle source of krypton and xenon is the atmosphere. Atmospheric air contains about 1.1 ppm (parts per million) of krypton and about 0.08 ppm of xenon. Generally, krypton and xenon are recovered from the air in conjunction with a comprehensive air separation process which separates air into oxygen and nitrogen.
  • the air separation process may produce gaseous or liquid oxygen, or may produce both, and the krypton and xenon will concentrate in either oxygen product. It is desirable to further concentrate the krypton and xenon so that their separation from oxygen can be carried out efficiently.
  • the krypton-xenon concentration process must be carried out at the same time as the air separation process because it is impractical to store gaseous oxygen in the quantities produced by an air separation plant.
  • a process for the recovery of krypton and xenon from oxygen containing hydrocarbons obtained in the reboiler of an air separation column is known from US-A 3 768 270.
  • a major part of the oxygen to be processed is withdrawn from the reboiler as saturated vapor (feed gas), and a small part is withdrawn as feed liquid.
  • the feed liquid is partially vaporized in a first reboiler to produce a vapor and a liquid krypton-xenon concentrate, the latter being recovered whereas the former is admixed with the feed gas.
  • the mixture of feed gas and vapor from the first reboiler is introduced into a rectification column having a second reboiler, and is passed against downflowing reflux liquid to thereby strip krypton and xenon from the mixture to the reflux liquid and to produce a richer liquid and a lean vapor.
  • the former is combined with the liquid from the first reboiler, whilst a part of the latter is heated and compressed and then cooled by indirect heat exchange with the heating lean vapor.
  • a major part of the cooled lean vapor is condensed in the second reboiler by indirect heat exchange with the partially vaporizing reboiling liquid and the remainder of the cooled lean vapor is condensed in the first reboiler by indirect heat exchange with the feed liquid, to produce lean liquids which are combined.
  • a portion of the combined lean liquids is passed to the column to form the reflux liquid, and a portion of the combined lean liquids is recovered as liquid product substantially free of rare gases.
  • the prior process requires two separate feeds (gaseous and liquid oxygen) and thus requires two separate reboilers. Because both gaseous and liquid oxygen feeds are needed the process must be operated proximate to an air separation plant.
  • a process for the production of a krypton-xenon concentrate from a feed liquid which is the only feed to the process, while also recovering a liquid product substantially free of rare gases, comprising:
  • rare gas means krypton or xenon.
  • the terms “lean”, “leaner”, “rich” and “richer”, refer to the concentration of rare gases, unless specifically indicated otherwise.
  • integral heat pump circuit means an arrangement whereby the heat pump circuit is combined with the separation column and utilizes process fluid available from the separation column.
  • heating zone means a heat exchange zone where entering liquid is indirectly heated and thereby partially vaporized to produce gas and remaining liquid. The remaining liquid is thereby enriched in the less volatile components present in the entering liquid.
  • directly heat exchange means the bringing of two fluid streams into heat exchange relation without any physical contact or intermixing of the fluids with each other.
  • the term "equilibrium stage” means a vapor-liquid contacting stage whereby the vapor and liquid leaving that stage are in mass transfer equilibrium.
  • an equilibrium stage would correspond to a theoretical tray or plate.
  • an equilibrium stage would correspond to that height of column packing equivalent to one theoretical plate.
  • An actual contacting stage i.e. trays, plates, or packing, would have a correspondence to an equilibrium stage dependent on its mass transfer efficiency.
  • the term "column” means a distillation or fractionation column, i.e., a contacting column or zone wherein liquid and vapor phases are countercurrently contacted to effect separation of a fluid mixture, as for example, by contacting of the vapor and liquid phases on a series of vertically spaced trays or plates mounted within the column or alternatively, on packing elements with which the column is filled.
  • a distillation or fractionation column i.e., a contacting column or zone wherein liquid and vapor phases are countercurrently contacted to effect separation of a fluid mixture, as for example, by contacting of the vapor and liquid phases on a series of vertically spaced trays or plates mounted within the column or alternatively, on packing elements with which the column is filled.
  • double column is used herein to mean a high pressure column having its upper end in heat exchange relation with the lower end of a low pressure column.
  • Figure 1 is a schematic flow diagram of one preferred embodiment of the process of this invention.
  • the schematic representation of Figure 1 is particularly preferred in that it shows the feed to the krypton-xenon concentration process as coming from a double-column air separation plant which produces both gaseous and liquid oxygen product and shows a modification to the double-column process which enables virtually all of the krypton and xenon in the feed air to settle in the liquid oxygen rather than in the gaseous oxygen.
  • liquid stream 32 comprising oxygen, krypton and xenon is passed, such as by pump means 33, as stream 34 to reboiling zone 36.
  • liquid feed stream 34 is combined with liquid from column 35 and the resulting combined stream 42 is passed to reboiling zone 36.
  • concentration of krypton and xenon in the liquid feed stream 34 may be any effective concentration but, in general, the concentration of krypton will be at least 10 ppm and the concentration of xenon will be at least 1 ppm in liquid feed stream 34.
  • the source of the liquid feed to the process of this invention may be any source of rare gas-containing liquid oxygen.
  • Figure 1 shows one such source as the liquid from the sump of a lower pressure column of a double column air separation process 10 which can produce both liquid and gaseous oxygen products.
  • this liquid 26 may be passed to storage reservoir 31 prior to use in the process of this invention.
  • Storage reservoir 31 may be supplied with suitable feed liquid from sources other than or in addition to the feed from the illustrated double column air separation plant.
  • Figure 1 demonstrates one of the advantages of the process of this invention, in that the process need not be tied to a comprehensive air separation process.
  • the only input to the process of this invention is liquid feed stream 34 which may be from any suitable source.
  • the entire krypton-xenon concentration process 30, including mass transfer in the column, heat transfer in the integral heat pump circuit, and the concentrating phase change in the reboiling zone, is carried out with no other stream input to the process. This allows the process of this invention to stand alone and allows for krypton-xenon concentration with a process simplified considerably over heretofore available processes.
  • reboiling liquid 61 in the reboiling zone is partially vaporized by heat exchange with condensing liquid in condenser 37 resulting in a vapor 43 and a krypton-xenon concentrate 40 which may be recovered for further use.
  • the krypton concentration in concentrate 40 will be at least 200 ppm and preferably is at least 400 ppm, and the xenon concentration in concentrate 40 is at least 15 ppm and preferably is at least 30 ppm.
  • Vapor 43 which is leaner in krypton and xenon than is the feed liquid to the reboiling zone, is passed up through column 35 against downflowing reflux liquid.
  • Figure 1 illustrates reboiling zone 36 as being apart from column 35 although the reboiling zone could be within and at the bottom of column 35.
  • the vapor 43 is introduced into column 35 at the bottom of the column.
  • krypton and xenon in vapor 43 is stripped from the vapor into downflowing reflux liquid.
  • the resulting krypton-xenon enriched liquid 41 is passed to the reboiling zone to form part of reboiling liquid 61.
  • Column 35 operates at a pressure in the range of from 69 to 517 kPa (10 to 75 psia), preferably from 103 to 207 kPa (15 to 30 psia), and serves to strip a significant portion, and preferably substantially all, of the krypton and xenon in vapor 43 into the downflowing reflux liquid. This results in vapor stream 44 being withdrawn from column 35, preferably at the top of column 35, in a lean condition and preferably substantially free of rare gases.
  • Lean vapor stream 44 comprised substantially of oxygen, is heated by indirect heat exchange in heat exchanger 39, and the heated stream 45 is compressed in compressor 38 to form compressed stream 46.
  • Stream 45 need undergo only a small amount of compression and preferably stream 46 is at a pressure not more than 207 kPa (30 psi), most preferably not more than 103 kPa (15 psi), greater than stream 45.
  • the compressed stream may be cooled versus cooling water.
  • the compressed stream 45 is then cooled by indirect heat exchange by passage through heat exchanger 39 against the heating vapor stream 44 and the resulting cooled compressed lean vapor stream 47 is passed to condenser 37 of reboiling zone 36.
  • lean liquid 48 is condensed by indirect heat exchange with the partially vaporizing reboiling liquid to produce lean liquid 48.
  • a portion 49 of this lean liquid 48 comprising from 10 to 40 percent, preferably from 15 to 25 percent of lean liquid 48 is expanded through valve 51 and passed as steam 52, to column 35, preferably at the top of the column, to form the aforedescribed downflowing reflux liquid.
  • Another portion 50 of lean liquid 48 is recovered as liquid product comprised substantially of oxygen and being substantially free of rare gases.
  • stream 50 will have a krypton concentration of not more than 5 ppm, preferably not more than 1 ppm, and a negligible xenon concentration.
  • the feed liquid provides for the krypton-xenon mass transfer within column 35, for the heat transfer in the integral heat pump circuit associated with heat exchanger 39, and also for the concentrating phase change in reboiling zone 36. Because the heat exchange in reboiling zone 36 is between very similar fluids, i.e., both the reboiling liquid 61 and the condensing compressed lean vapor 47 are generally 99 percent or more oxygen, the heat exchange within reboiling zone 36 can be carried out with only a small amount of compressed in compressor 38.
  • the integral heat pump circuit also serves to reduce the complexity of the concentration process since other fluids, such as nitrogen or argon, are not needed as heat exchange media. This also serves to better enable the process of this invention to stand alone, independent of other cryogenic processes.
  • Figure 1 illustrates a particularly preferred arrangement wherein the liquid feed to the krypton-xenon concentration process is taken from a double column air separation which produces both gaseous and liquid oxygen product and which has been modified from the conventional dual product double column arrangement so as to place virtually all of the atmospheric krypton and xenon in the liquid product rather than the gaseous product.
  • feed air 14 is introduced into high pressure column 13, operating a pressure of from 517 to 1034 kPa (75 to 150 psia), wherein it is separated into nitrogen-richer vapor 16 and oxygen- richer liquid 15.
  • Vapor 16 is condensed in condenser 12 by indirect heat exchange with low pressure column bottoms 62 and the resulting nitrogen-richer liquid 17 is passed to both the high pressure column, as stream 19, and to the low pressure column, as stream 18 through valve 22 and stream 23, to serve a liquid reflux for the columns.
  • Liquid 15 is expanded through valve 20 and passed as stream 21 to the low pressure column as partially flashed feed.
  • Air stream 51 which may be used for cold end heat exchanger temperature regulation and/or to develop plant refrigeration is also introduced into column 11 as feed.
  • Column 11 operates at a pressure lower than column 13 and in the range of from 103 to 207 kPa (15 to 30 psia). Within column 11 the various input streams are separated into a nitrogen-rich component which is removed as stream 24 and an oxygen-rich component. The oxygen-rich component is withdrawn from the column as gaseous stream 25 and liquid stream 26.
  • the gaseous oxygen product is withdrawn from above the liquid bottoms in such a manner that the two withdrawn streams are in equilibrium. Accordingly, the krypton and xenon will be in equilibrium in both the withdrawn product streams. Although the equilibrium krypton and xenon content of the liquid product is higher than that of the gas product, often the quantity of liquid product is much less than the gas product and thereby the loss of krypton and xenon with the gas product is significant.
  • the double column arrangement illustrated in Figure 1 withdraws the gaseous oxygen product 25 from column 11 at a point above at least one equilibrium stage higher than the column 11 sump, in this case above tray 27.
  • the gaseous oxygen product may be withdrawn from even higher above the sump, such as above trays 28 or 29.
  • the optimum removal point will depend on the value of the marginal krypton-xenon gained relative to the extra trays in the low pressure column.
  • the liquid oxygen product 26 will be from about 2 to about 75 percent of the total oxygen product from column 11, preferably from about 5 to 30 percent and most preferably about 20 percent.
  • the double column process illustrated in Figure 1 is particularly advantageous when employed in conjunction with the krypton-xenon concentration process of this invention.
  • the double column process concentrates virtually all of the atmospheric krypton and xenon in the liquid oxygen product which is then used as feed for the process of this invention.
  • the krypton-xenon concentration process of this invention produces a liquid oxygen product stream containing only a small amount of, or negligible, rare gases.
  • putting the two processes together as illustrated in Figure 1 one may recover a gaseous oxygen product 25, a liquid oxygen product 50 and a krypton-xenon concentrate 40 containing virtually all of the krypton and xenon in the atmospheric air feed. This very desirable result is accomplished at high efficiency and in an uncomplicated and safe manner.
  • the process of this invention effectively produces a krypton- xenon concentrate with very little krypton and xenon lost by being in streams other than the concentrate product stream.
  • the process of this invention accomplishes this using a liquid feed yet also produces a liquid product substantially free of rare gases.
  • the vast majority of the liquid feed generally at least 75 percent and in this case 92 percent, is recovered a liquid oxygen product and only a small amount of the liquid feed is needed to form the krypton-xenon concentrate.
  • the process of this invention is able to achieve these desirable results without any other stream inputs, such as a nitrogen or argon heat pump cycle, and without the need to return any process stream back to an air separation plant, thereby enabling this process to stand alone with no need for an associated cryogenic plant. Still further, the process of this invention, employing the defined combination of process steps and using the liquid feed as the only process stream, accomplishes all of these desirable results without the need for a large energy input to drive the separation.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Emergency Medicine (AREA)
  • Separation By Low-Temperature Treatments (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)

Claims (16)

1. Verfahren zum Gewinnen eines Krypton/Xenon-Konzentrats aus einer die einzige Beschickung des Verfahrens bildenden flüssigen Beschickung, wobei ferner ein von Edelgasen im wesentlichen freies flüssiges Produkt gewonnen wird, bei dem:
1) eine Sauerstoff, Krypton und Xenon aufweisende Einsatzflüssigkeit einer Reboilerzone zur Bildung einer Reboilerflüssigkeit zugeführt wird;
2) die Reboilerflüssigkeit zur Bildung eines Dampfes und eines flüssigen Krypton/Xenon-Konzentrats teilverdampft wird;
3) das Krypton/Xenon-Konzentrat gewonnen wird;
4) der Dampf im Gegenstrom zu einer nach unten strömenden Rücklaufflüssigkeit in einer Kolonne geleitet wird;
5) Krypton und Xenon von dem Dampf in die Rücklaufflüssigkeit abgetrieben werden, um einen mageren Dampf und eine reichere Flüssigkeit zu bilden;
6) die reichere Flüssigkeit der Reboilerzone zwecks Bildung eines Teils der Reboilerflüssigkeit zugeleitet wird;
7) magerer Dampf aus der Kolonne abgezogen wird;
8) der abgezogene magere Dampf erhitzt wird;
9) der erhitzte magere Dampf verdichtet wird;
10) der verdichtete magere Dampf durch indirekten Wärmeaustausch mit dem zu erhitzenden mageren Dampf gekühlt wird;
11) der gekühlte magere Dampf in der Reboilerzone durch indirekten Wärmeaustausch mit der teilverdampfenden Reboilerflüssigkeit unter Ausbildung einer mageren Flüssigkeit kondensiert wird;
12) ein Teil der mageren Flüssigkeit der Kolonne zur Bildung der Rücklaufflüssigkeit zugeleitet wird; und
13) ein Teil der mageren Flüssigkeit als von Edelgasen im wesentlichen freies flüssiges Produkt gewonnen wird.
2. Verfahren nach Anspruch 1, wobei die Kryptonkonzentration in der flüssigen Beschickung mindestens 10 ppm beträgt.
3. Verfahren nach Anspruch 1, wobei die Xenonkonzentration in der flüssigen Beschickung mindestens 1 ppm beträgt.
4. Verfahren nach Anspruch 1, wobei die Reboilerzone innerhalb der Kolonne angeordnet ist.
5. Verfahren nach Anspruch 1, wobei die Reboilerzone von der Kolonne getrennt ist.
6. Verfahren nach Anspruch 1, wobei die flüssige Beschickung und die reichere Flüssigkeit vor dem Einleiten in die Reboilerzone zusammengefaßt werden.
7. Verfahren nach Anspruch 1, wobei die Kolonne bei einem Druck im Bereich von 69 bis 517 kPa (10 bis 75 psia) arbeitet.
8. Verfahren nach Anspruch 1, wobei der erhitzte magere Dampf verdichtet wird, um seinen Druck um nicht mehr als 207 kPa (30 psi) zu steigern.
9. Verfahren nach Anspruch 1, wobei der erhitzte magere Dampf verdichtet wird, um seinen Druck um nicht mehr als 103 kPa (15 psi) zu steigern.
10. Verfahren nach Anspruch 1, wobei der Teil der mageren Flüssigkeit, welcher der Kolonne als Rücklaufflüssigkeit zugeleitet wird, 10 bis 40 Prozent der mageren Flüssigkeit ausmacht.
11. Verfahren nach Anspruch 1, wobei die Kryptonkonzentration in dem Krypton/Xenon-Konzentrat mindestens 200 ppm beträgt.
12. Verfahren nach Anspruch 1, wobei die Xenonkonzentration in dem Krypton/Xenon-Konzentrat mindestens 15 ppm beträgt.
13. Verfahren nach Anspruch 1, wobei das von Edelgasen im wesentlichen freie flüssige Produkt auf Volumenstrombasis mindestens 75 Prozent der flüssigen Beschickung ausmacht.
14. Verfahren nach Anspruch 1, wobei die flüssige Beschickung von einer kryogenen Doppelkolonnen-Luftzerlegungsanlage kommt.
15. Verfahren nach Anspruch 14, wobei die Luftzerlegungsanlage zusätzlich zu einer die flüssige Beschickung bildenden Flüssigkeit gasförmiges Sauerstoffprodukt erzeugt.
16. Verfahren nach Anspruch 15, wobei das gasförmige Sauerstoffprodukt aus der Luftzerlegungsanlage an einer Stelle abgezogen wird, die mindestens eine Gleichgewichtsstufe über der Stelle liegt, an welcher die die flüssige Beschickung bildende Flüssigkeit abgezogen wird.
EP85113013A 1984-08-16 1985-10-14 Verfahren zum Gewinnen eines Krypton-Xenonkonzentrats aus einer flüssigen Mischung Expired EP0218740B1 (de)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US06/641,553 US4574006A (en) 1984-08-16 1984-08-16 Process to produce a krypton-xenon concentrate from a liquid feed
DE8585113013T DE3573307D1 (en) 1985-10-14 1985-10-14 Process to produce a krypton-xenon concentrate from a liquid feed
EP85113013A EP0218740B1 (de) 1985-10-14 1985-10-14 Verfahren zum Gewinnen eines Krypton-Xenonkonzentrats aus einer flüssigen Mischung
AT85113013T ATE46761T1 (de) 1985-10-14 1985-10-14 Verfahren zum gewinnen eines kryptonxenonkonzentrats aus einer fluessigen mischung.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP85113013A EP0218740B1 (de) 1985-10-14 1985-10-14 Verfahren zum Gewinnen eines Krypton-Xenonkonzentrats aus einer flüssigen Mischung

Publications (2)

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EP0218740A1 EP0218740A1 (de) 1987-04-22
EP0218740B1 true EP0218740B1 (de) 1989-09-27

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EP85113013A Expired EP0218740B1 (de) 1984-08-16 1985-10-14 Verfahren zum Gewinnen eines Krypton-Xenonkonzentrats aus einer flüssigen Mischung

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EP (1) EP0218740B1 (de)
AT (1) ATE46761T1 (de)
DE (1) DE3573307D1 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3839394A1 (de) 2019-12-18 2021-06-23 Air Products And Chemicals, Inc. Rückgewinnung von krypton und xenon aus flüssigem sauerstoff

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115854653B (zh) * 2023-02-27 2023-05-12 河南心连心深冷能源股份有限公司 一种采用同一热泵生产贫氪氙和超纯氧的装置及生产工艺

Family Cites Families (4)

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Publication number Priority date Publication date Assignee Title
DE1667639A1 (de) * 1968-03-15 1971-07-08 Messer Griesheim Gmbh Verfahren zum Gewinnen eines Krypton-Xenon-Gemisches aus Luft
GB1371327A (en) * 1970-10-12 1974-10-23 British Oxygen Co Ltd Air separation
GB1367625A (en) * 1970-11-27 1974-09-18 British Oxygen Co Ltd Air separation
JPS5743185A (en) * 1980-08-29 1982-03-11 Nippon Oxygen Co Ltd Production of krypton and xenon

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3839394A1 (de) 2019-12-18 2021-06-23 Air Products And Chemicals, Inc. Rückgewinnung von krypton und xenon aus flüssigem sauerstoff

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EP0218740A1 (de) 1987-04-22
DE3573307D1 (en) 1989-11-02
ATE46761T1 (de) 1989-10-15

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