US2608070A - Method and means for distillation of low boiling point liquids - Google Patents
Method and means for distillation of low boiling point liquids Download PDFInfo
- Publication number
- US2608070A US2608070A US648908A US64890846A US2608070A US 2608070 A US2608070 A US 2608070A US 648908 A US648908 A US 648908A US 64890846 A US64890846 A US 64890846A US 2608070 A US2608070 A US 2608070A
- Authority
- US
- United States
- Prior art keywords
- rectification
- column
- distillation
- compressors
- evaporator
- 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 - Lifetime
Links
Images
Classifications
-
- 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
- F25J3/044—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 single pressure main column system only
-
- 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
- F25J3/04048—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of cold gaseous streams, e.g. intermediate or oxygen enriched (waste) streams
-
- 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
- F25J3/04048—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of cold gaseous streams, e.g. intermediate or oxygen enriched (waste) streams
- F25J3/0406—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of cold gaseous streams, e.g. intermediate or oxygen enriched (waste) streams of nitrogen
-
- 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
- F25J3/04048—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of cold gaseous streams, e.g. intermediate or oxygen enriched (waste) streams
- F25J3/04072—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of cold gaseous streams, e.g. intermediate or oxygen enriched (waste) streams of argon or argon enriched stream
-
- 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
- F25J3/04284—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams
- F25J3/0429—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams of feed air, e.g. used as waste or product air or expanded into an auxiliary column
- F25J3/04296—Claude expansion, i.e. expanded into the main or 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
- F25J3/04284—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams
- F25J3/04327—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams of argon or argon enriched stream
-
- 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
-
- 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
- F25J3/04351—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 nitrogen
-
- 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
- F25J3/04369—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 argon or argon enriched stream
-
- 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
- F25J3/04375—Details relating to the work expansion, e.g. process parameter etc.
- F25J3/04381—Details relating to the work expansion, e.g. process parameter etc. using work extraction by mechanical coupling of compression and expansion so-called companders
-
- 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
- F25J3/04648—Recovering noble gases from air argon
- F25J3/04654—Producing crude argon in a crude argon column
- F25J3/0466—Producing crude argon in a crude argon column as a parallel working rectification column or auxiliary column system in a single pressure main column system
-
- 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
- F25J2200/50—Processes or apparatus using separation by rectification using multiple (re-)boiler-condensers at different heights of the 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
Definitions
- the present invention relates to. method and means for rectification and distillation of liquid with low temperature boiling points.
- the main difficulty encountered in the fractional distillation or rectification of liquids boiling at low temperatures such asoccur for example in the distillation of air, water gas, or coal gas from the liquid phase consists inv liquifying the more volatile fraction.
- the present invention is characterised bythe direct liquefaction of the most volatile components at the cold end of the cycle by a compressor.
- FIG. 1 The, appended schematic diagrams illustrate: in Figure 1, the apparatusfor liquifying the most volatile component in the case of a binary mixture;. in Fig. 2, a variant of the system, having a second compressor coupled in parallelto increase the efliciency of the rectifying. column, and in Fig. 3, a system for separating mixtures con-. taining three, or. more components.
- Fig. 2 showsthe samearrangementas in Fig. 1 with one additional compressor.
- the, gas of which the reflux is to be made, is removed'jrom the fractionating column; at two, poi ts, .1 at the top, through p pe. I: a d one. o ewhatlow r t u h p p . The part of the.
- Fig. 3 A system arranged for this purpose is shown in Fig. 3, in which there are two fractionating columns of the type shown in Fig. 1.
- FIG. 3 illustrates the use of one compressor per fractionating column. It is clear, however, that the efficiency of the system may be improved by the addition of further compressors according to the system illustrated in Fig. 2.
- the gas is passed through the expansion machine 5 to column I the two less volatile components collecting in the evaporator ID from which they fiow through pipe 22 to the central part of the fractionating column 2 I.
- the reflux is produced by means of the compressor I6 to which the gas is led through pipe 20.
- the compressed gas passes through pipe [1 to the evaporator IS in which it is condensed, the resulting reflux liquid being directed through the pipe and valve l9 to the upper end oi. the fractionating column.
- the component of intermediate boiling point, in this caseargon is led through the heat exchanger 24 through pipe 23, the component of high boiling pointoxygen-leaving the system through the pipe I4 and heat exchanger 2.
- each additional component requires an additional fractionating column and heat exchanger for its separation from the original mixture.
- the fractionators may be supplied with one or more compressors.
- the principle described above may be applied to all existing types of fractionating columns such as those having perforated plates, rotating discs etc.
- the heat exchangers 2, 3 and 24 may be of any existing types.
- One of the advantages of the system according to the present invention lies in the possibility of driving the compressors from the shaft of the expansion engine. In this case, the work expended on compressing the most volatile component and consequently raising its temperature is compensated by the temperature drop in the expansion engine and in this manner, the temperature balance in the fractionating column is not violated.
- Another feature of the proposed system lies in the fact that the reflux is usually composed of only a part of the total quantity of the gas flowing through the expander and consequently the pressure of the gas leaving the compressor may be made higher thanthat of the gas entering the expander. Furthermore when the efficiencies of the compressor and expansion engine are sufficiently high, the pressure of the most volatile component (nitrogen, in the case when air is being separated into its two main components oxygen and nitrogen) can be made higher 'at the evaporation point of the cycle than that of the air entering the system. This assists in the formation of the reflux used in the iractionating column. This is a marked advantage over the system proposed by Linde and Frenkel.
- a further increase in the efficiency of the system may be obtained by adding an auxiliary load I5 to the axle of the expansion machine as shown in Figures 1, 2 and 3. This may be a dynamo or any other power absorbing machine.
- a method of rectification and fractional distillation of liquids boiling at low temperatures comprising removing at least one of the most volatile fractions of the composition undergoing fractionation from a first point at the top portion of a rectification zone, compressing at least a part of the fraction removed at a temperature level corresponding substantially to the temperature at the top of said rectification zone and returning the compressed material as a refiux to the top portion of the rectification zone,
- Means for effecting rectification and fractional distillation of liquids boiling at low temperatures comprising a rectification column, an
- Means for effecting rectification and fractional distillation of liquids boiling at low temperatures comprising a rectification column having two evaporators arranged therein at different levels, means for leading a normally gaseous fluid and for discharging it into the column above said evaporators, an expander interposed in said means for utilizing the expansion of said fluid to create mechanical energy.
- first and second compressors driven by said expander first and second conduits leading from spaced points of the rectification column above the point where the normally gaseous fluid is introduced directly to the compressors respectively, a passageway connecting one of said compressors to one of the evaporators, another passageway connecting the other compressor to the other one of said evaporators, a third passageway connecting the evaporator at the lower level to the top of the column, and a fourth passageway connecting the other evaporator to the column at a point above that where the normally gaseous fluid is introduced.
- Means for effecting rectification and fractional distillation of liquids boiling at low temperatures comprising rectification column means having a plurality of evaporators arranged therein at diiferent levels, a plurality of heat exchangers, an expansion engine, conduit means for passing a normally gaseous fluid through said heat exchangers and the expansion engine and for discharging the same into the rectification column between the top and bottom thereof and at a point above said evaporators, a plurality of compressors corresponding in number to the number of the evaporators and driven by said expansion engine, passageways placing points in the rectification means above the evaporators in direct communication respectively with the re spective compressors, other passageways placing the compressors in communication with the respective evaporators, other passageways placing each evaporator in communication with the rectification column means at a point above that where the evaporator is located, and conduit means for leading fractions from the rectification column means through the heat exchangers.
- Means for effecting rectification and fractional distillation of liquids boiling at low temperatures, and containing at least three components comprising series connected rectification columns each having at least one evaporator arranged therein, the number of said rectification columns being one less than the number of components subjected to distillation, at least one compressor for each rectification column, communicating with the corresponding evaporator in said columns, an expander, heat exchangers, means for passing a normally gaseous fluid through said heat exchangers and said expander and for discharging the same into at least one of said rectification columns between the top and bottom thereof, means for leading gaseous fractions from the tops of the columns directly to the compressors, means for utilizing the mechanical energy of expanding gases in the expander to drive said compressors, means for leading fluid through each evaporator to the rectification column in which the evaporator is located and for discharging the same into that column at a higher elevation than the evaporator, and means for passing fluid from each rectification column through at least one
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Separation By Low-Temperature Treatments (AREA)
Description
Aug. 26, 1952 P KAPlTZA 2,608,070
METHOD AND MEANS FOR DISTILLATION OF LOW BOILING POINT LIQUIDS Filed Feb. 20, 1946 Sl-IEETS-Sl-IEET 1 I I o .1, n
f/ l Z I 5x078? W fica'i' [Xe/wa er" 7,2 /0
l! A; [/ecfn ca/Iymsww Expansion [pig/me. l
III- 2.
flea? ,E'xchan er f INVENTOR.
as) x: i BY Pa er Z. K6791 2 Aug. 26, 1952 P. 1.. KAPITZA METHOD AND MEANS FOR DISTILLATION OF LOW BOILING POINT LIQUIDS 2 SHEETS-SHEET 2 Filed Feb. 20, 1946 MN M m WRN Patented Aug. 26, 1952 METHODAND ll/IEANS FOR DISTILLATIQN LOW BOILING POINTLIQ U IDSj Peter Leonidovitch; Kapitza, Moscow, Union of Soviet Socialist Republics ApplicationFebruary 20, 1946, Serial No, 648,908 In, the. Union. of Soviet Socialist Republics February 11, 1944 6 Claims. (Cl. 6.2. 1 23.-)
The present inventionrelates to. method and means for rectification and distillation of liquid with low temperature boiling points.
The main difficulty encountered in the fractional distillation or rectification of liquids boiling at low temperatures such asoccur for example in the distillation of air, water gas, or coal gas from the liquid phase consists inv liquifying the more volatile fraction.
In particular, when producing oxygen from air the greatest difiiculty is encountered in obtaining a reflux liquid of liquid nitrogen. Hitherto these difiiculties were overcome by the use of double columns (for example, the double columns used in the Linde and Claude methods for the fractional distillation of liquid air), in which one column serves to obtain a reflux of the most volatile component, while the other serves for the actual distillation. This method requires that the air be supplied at high pressures While the design of the apparatus necessitates the use of additional condensers and. evaporators. This reduces the efliciency of the whole system considerably and requires a complicated construction of large dimensions.
Proposals have been made in the art to obtain a reflux by compressing the most volatile components in a compressor, the compression being performed at a temperature higher than the temperature at which said component leaves the column and to afford this'said' component is led through a series of heat exchangers; In this connection I cite United States Patent 2,095,809 disclosing ample evidenceof the use of the abovementioned principle.
The present invention is characterised bythe direct liquefaction of the most volatile components at the cold end of the cycle by a compressor.
The, appended schematic diagrams illustrate: in Figure 1, the apparatusfor liquifying the most volatile component in the case of a binary mixture;. in Fig. 2, a variant of the system, having a second compressor coupled in parallelto increase the efliciency of the rectifying. column, and in Fig. 3, a system for separating mixtures con-. taining three, or. more components.
For the sake of simplicity and ease in de scribing the systems illustrated, all mechanisms 3, and by means of the-pipe 4% passes into the expansion engine I 5lwhichmay be of the turbine typeor any machine wherein the gas. is expanded, this expansion being accompanied by the production of mechanical energy delivered for adequate use after'which the cooledand partly liquefied gas is conducted through pipe 6 to the: column. I. Themost volatile component concentrates in the upperpartot 'the column, and is: removed bypipe ll and passed to the compressor 8 in which it is. compressed to a pressure, at which liquefaction oi the reflux occurs. Through pipefl thecompre'ssed gas-flows into the. evaporator lllsituated'atthe lower'end of thecolumn in which thecomponent of higher boil ing point collects. The pressureat the exhaust ofthe compressor 8- ismade'such that themost volatile component is condensed in the evaporator- It; This liquified'component is. directed through pipe having a valve l2-to the top of column: I andflowstothebottom oflthe column 1 passing successively over the transverse perforated platesinside the column. The separated fractiom are removed by-p pes 13' and 4 pa ing through heatexchangers 2 and 3. The eff ciency of the, fractionating column can be increasedvery simply by the addition of other compressors working in; parallel with the first.
The conditionsfon condensing and evaporating the; reflux: at various levels in the fractionatorare in accordance with the conditions requisitefor improving theefiiciency of the system. Fig. 2 showsthe samearrangementas in Fig. 1 with one additional compressor. According to the'arrangementof the apparatus shown in Fig. 2, the, gas: of which the reflux is to be made, is removed'jrom the fractionating column; at two, poi ts, .1 at the top, through p pe. I: a d one. o ewhatlow r t u h p p .The part of the. gas; removed throughpipe 7 passes through the; cycle described above while that portion which isremoved by pipe 25 is di" rected; throu h. a second compressor It out of- Which itis led throu h Pipe: ll to the evaporator I 8 arranged intheupp r half ofthe fractionating column I. The liquified gas. isled into the column through the pipe and valve [9,- the inlet being somewhat higher in the column I than the exhaust pipe 2,0. Followingthe above principle a third, fourth, and further compressors may-be added, and the more of such compressors thereare in operation, thecloser .will. be the mode and. the higher will be its.
The same principle may be applied to the separation of three or more components from a gaseous mixture such as the argon, nitrogen and oxygen in air. A system arranged for this purpose is shown in Fig. 3, in which there are two fractionating columns of the type shown in Fig. 1.
The diagram shown in Fig. 3 illustrates the use of one compressor per fractionating column. It is clear, however, that the efficiency of the system may be improved by the addition of further compressors according to the system illustrated in Fig. 2.
In the case of a trinary mixture, the gas is passed through the expansion machine 5 to column I the two less volatile components collecting in the evaporator ID from which they fiow through pipe 22 to the central part of the fractionating column 2 I. In this column, the reflux is produced by means of the compressor I6 to which the gas is led through pipe 20. The compressed gas passes through pipe [1 to the evaporator IS in which it is condensed, the resulting reflux liquid being directed through the pipe and valve l9 to the upper end oi. the fractionating column. The component of intermediate boiling point, in this caseargon, is led through the heat exchanger 24 through pipe 23, the component of high boiling pointoxygen-leaving the system through the pipe I4 and heat exchanger 2.
It is clear from the principle illustrated in Fig. 3 that each additional component requires an additional fractionating column and heat exchanger for its separation from the original mixture. The fractionators may be supplied with one or more compressors.
Obviously, the principle described above may be applied to all existing types of fractionating columns such as those having perforated plates, rotating discs etc. Similarly, the heat exchangers 2, 3 and 24 may be of any existing types.
One of the advantages of the system according to the present invention lies in the possibility of driving the compressors from the shaft of the expansion engine. In this case, the work expended on compressing the most volatile component and consequently raising its temperature is compensated by the temperature drop in the expansion engine and in this manner, the temperature balance in the fractionating column is not violated.
Another feature of the proposed system lies in the fact that the reflux is usually composed of only a part of the total quantity of the gas flowing through the expander and consequently the pressure of the gas leaving the compressor may be made higher thanthat of the gas entering the expander. Furthermore when the efficiencies of the compressor and expansion engine are sufficiently high, the pressure of the most volatile component (nitrogen, in the case when air is being separated into its two main components oxygen and nitrogen) can be made higher 'at the evaporation point of the cycle than that of the air entering the system. This assists in the formation of the reflux used in the iractionating column. This is a marked advantage over the system proposed by Linde and Frenkel.
The greater density of gases at low temperatures enables greater pressure changes to be obtained in compressors having few compression stages (such as turbine compressors) and in expansion engines of the turbine type and consequently increases their efiiciency as 'a result of which, the use of this type of compressor and expansion engine is to be recommended in installation of the proposed type.
A further increase in the efficiency of the system may be obtained by adding an auxiliary load I5 to the axle of the expansion machine as shown in Figures 1, 2 and 3. This may be a dynamo or any other power absorbing machine.
The method advanced in the present invention for producing a reflux liquid of the most volatile components by means of a compressor at the cold end of a cycle can be applied in practice in various ways as is obvious from the discussion of the examples given above. Furthermore it is clear that the application of the method considerably simplifies the construction of fractional stills, affording new possibilities to the art of low temperature distillation.
Since details of method and means for the rectification and distillation of liquid with low temperature boiling points may be modified, the scope of the invention is defined by the claims as hereunto appended.
I claim:
1. A method of rectification and fractional distillation of liquids boiling at low temperatures, comprising removing at least one of the most volatile fractions of the composition undergoing fractionation from a first point at the top portion of a rectification zone, compressing at least a part of the fraction removed at a temperature level corresponding substantially to the temperature at the top of said rectification zone and returning the compressed material as a refiux to the top portion of the rectification zone,
feeding compressed gases to the rectification zone between the top and bottom thereof, expanding the gases so fed, and utilizing the mechanical energy released by said expansion for compressing said part of the fraction removed from the rectification zone at the first point.
2. In the rectification and fractional distillation of liquids boiling at the low temperatures, the process which comprises liquefying gaseous components of normally gaseous material, ex-
panding the liquefied gas and introducing the same into a rectification zone between the top and bottom thereof, removing at least one of the most volatile fractions from the upper portion of said zone, compressing at least a part of said fraction at a temperature level corresponding substantially to the temperature at the top of said rectification zone, passing the compressed material through a lower portion of the rectification zone and utilizing the same for heating that portion of the zone, subsequently passing the compressed material to the top portion of the zone and utilizing it as a reflux therein, and utilizing mechanical energy released by the expansion of the liquefied gas to compress the part of the fraction removed from the top portion of the rectification zone.
3. Means for effecting rectification and fractional distillation of liquids boiling at low temperatures, comprising a rectification column, an
through the evaporator, and means for leading said fraction from the evaporator and for discharging it into the top of the column.
4. Means for effecting rectification and fractional distillation of liquids boiling at low temperatures, comprising a rectification column having two evaporators arranged therein at different levels, means for leading a normally gaseous fluid and for discharging it into the column above said evaporators, an expander interposed in said means for utilizing the expansion of said fluid to create mechanical energy. first and second compressors driven by said expander, first and second conduits leading from spaced points of the rectification column above the point where the normally gaseous fluid is introduced directly to the compressors respectively, a passageway connecting one of said compressors to one of the evaporators, another passageway connecting the other compressor to the other one of said evaporators, a third passageway connecting the evaporator at the lower level to the top of the column, and a fourth passageway connecting the other evaporator to the column at a point above that where the normally gaseous fluid is introduced.
5. Means for effecting rectification and fractional distillation of liquids boiling at low temperatures, comprising rectification column means having a plurality of evaporators arranged therein at diiferent levels, a plurality of heat exchangers, an expansion engine, conduit means for passing a normally gaseous fluid through said heat exchangers and the expansion engine and for discharging the same into the rectification column between the top and bottom thereof and at a point above said evaporators, a plurality of compressors corresponding in number to the number of the evaporators and driven by said expansion engine, passageways placing points in the rectification means above the evaporators in direct communication respectively with the re spective compressors, other passageways placing the compressors in communication with the respective evaporators, other passageways placing each evaporator in communication with the rectification column means at a point above that where the evaporator is located, and conduit means for leading fractions from the rectification column means through the heat exchangers.
6. Means for effecting rectification and fractional distillation of liquids boiling at low temperatures, and containing at least three components, comprising series connected rectification columns each having at least one evaporator arranged therein, the number of said rectification columns being one less than the number of components subjected to distillation, at least one compressor for each rectification column, communicating with the corresponding evaporator in said columns, an expander, heat exchangers, means for passing a normally gaseous fluid through said heat exchangers and said expander and for discharging the same into at least one of said rectification columns between the top and bottom thereof, means for leading gaseous fractions from the tops of the columns directly to the compressors, means for utilizing the mechanical energy of expanding gases in the expander to drive said compressors, means for leading fluid through each evaporator to the rectification column in which the evaporator is located and for discharging the same into that column at a higher elevation than the evaporator, and means for passing fluid from each rectification column through at least one of the heat exchangers.
PETER LEONIDOVITCH KAPITZA.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Name Date 1,449,291 Mewes et a1. Mar. 20, 1923 1,521,115 Mewes et al. Dec. 30, 1924 1,696,558 Van Nuys Dec. 25, 1928 2,095,809 Gomonet Oct. 12, 1937 2,180,435 Schlitt Nov. 21, 1939 2,270,852 Schuftan Jan. 27, 1942 2,355,167 Keith 1 Aug. 8, 194,4
Claims (1)
1. A METHOD OF RECTIFICATION AND FRACTIONAL DISTILLATION OF LIQUIDS BOILING AT LOW TEMPERARTURES, COMPRISING REMOVING AT LEAST ONE OF THE MOST VOLATILE FRACTIONS OF THE COMPOSITION UNDERGOING FRACTION ATOM FROM A FIRST POINT AT THE TOP PORTION OF A RECTIFICATION ZONE, COMPRESSING AT LEAST A PART OF THE FRACTION REMOVED AT A TEMPERATURE LEVEL CORRESPONDING SUBSTANTIALLY TO THE TEMPERATURE AT THE TOP OF SAID RECTIFICATION ZONE
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ZA2608070X | 1944-02-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2608070A true US2608070A (en) | 1952-08-26 |
Family
ID=25588430
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US648908A Expired - Lifetime US2608070A (en) | 1944-02-11 | 1946-02-20 | Method and means for distillation of low boiling point liquids |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2608070A (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2679730A (en) * | 1949-09-06 | 1954-06-01 | Esslingen Maschf | Handling of liquefied gases |
| US2705406A (en) * | 1951-11-30 | 1955-04-05 | Union Stock Yards & Transit Co | Apparatus and method for shipping and storing volatile hydrocarbons |
| US2762208A (en) * | 1952-12-19 | 1956-09-11 | Air Reduction | Separation of the constituents of air |
| US2820352A (en) * | 1953-11-07 | 1958-01-21 | Philips Corp | Method of separating the fractions of a gaseous mixture in a gas rectifying system |
| US2919554A (en) * | 1954-07-13 | 1960-01-05 | Philips Corp | Method of fractionating gas mixtures by means of a gas fractionating system comprising a rectifying column |
| US3131045A (en) * | 1958-05-19 | 1964-04-28 | Air Prod & Chem | Method and apparatus for fractionating gaseous mixtures |
| US3191393A (en) * | 1959-12-30 | 1965-06-29 | Air Reduction | Krypton-xenon separation from a gas mixture |
| US3292380A (en) * | 1964-04-28 | 1966-12-20 | Coastal States Gas Producing C | Method and equipment for treating hydrocarbon gases for pressure reduction and condensate recovery |
| US3397138A (en) * | 1965-12-02 | 1968-08-13 | Warren Petroleum Corp | Gas separation employing work expansion of feed and fractionator overhead |
| US3813890A (en) * | 1969-07-02 | 1974-06-04 | B Bligh | Process of continuous distillation |
| WO2016132083A1 (en) | 2015-02-20 | 2016-08-25 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Method and apparatus for separation at sub-ambient temperature |
| WO2019073132A1 (en) * | 2017-10-13 | 2019-04-18 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Method and device for separating air by cryogenic distillation |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1449291A (en) * | 1922-08-04 | 1923-03-20 | Mewes Rudolf Ferdinand | Process for separating gas mixtures under pressure |
| US1521115A (en) * | 1923-08-20 | 1924-12-30 | Mewes Rudolf Ferdinand | Process for separating gas mixtures under pressure |
| US1696558A (en) * | 1925-03-14 | 1928-12-25 | Air Reduction | Refrigeration |
| US2095809A (en) * | 1933-02-09 | 1937-10-12 | Air Reduction | Process for obtaining krypton and xenon from air |
| US2180435A (en) * | 1938-12-30 | 1939-11-21 | Air Reduction | Method of separating the constituents of gaseous mixtures |
| US2270852A (en) * | 1939-03-24 | 1942-01-27 | British Oxygen Co Ltd | Separating of gas mixtures |
| US2355167A (en) * | 1940-10-26 | 1944-08-08 | Kellogg M W Co | Process for the recovery of hydrocarbons |
-
1946
- 1946-02-20 US US648908A patent/US2608070A/en not_active Expired - Lifetime
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1449291A (en) * | 1922-08-04 | 1923-03-20 | Mewes Rudolf Ferdinand | Process for separating gas mixtures under pressure |
| US1521115A (en) * | 1923-08-20 | 1924-12-30 | Mewes Rudolf Ferdinand | Process for separating gas mixtures under pressure |
| US1696558A (en) * | 1925-03-14 | 1928-12-25 | Air Reduction | Refrigeration |
| US2095809A (en) * | 1933-02-09 | 1937-10-12 | Air Reduction | Process for obtaining krypton and xenon from air |
| US2180435A (en) * | 1938-12-30 | 1939-11-21 | Air Reduction | Method of separating the constituents of gaseous mixtures |
| US2270852A (en) * | 1939-03-24 | 1942-01-27 | British Oxygen Co Ltd | Separating of gas mixtures |
| US2355167A (en) * | 1940-10-26 | 1944-08-08 | Kellogg M W Co | Process for the recovery of hydrocarbons |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2679730A (en) * | 1949-09-06 | 1954-06-01 | Esslingen Maschf | Handling of liquefied gases |
| US2705406A (en) * | 1951-11-30 | 1955-04-05 | Union Stock Yards & Transit Co | Apparatus and method for shipping and storing volatile hydrocarbons |
| US2762208A (en) * | 1952-12-19 | 1956-09-11 | Air Reduction | Separation of the constituents of air |
| US2820352A (en) * | 1953-11-07 | 1958-01-21 | Philips Corp | Method of separating the fractions of a gaseous mixture in a gas rectifying system |
| US2919554A (en) * | 1954-07-13 | 1960-01-05 | Philips Corp | Method of fractionating gas mixtures by means of a gas fractionating system comprising a rectifying column |
| US3131045A (en) * | 1958-05-19 | 1964-04-28 | Air Prod & Chem | Method and apparatus for fractionating gaseous mixtures |
| US3191393A (en) * | 1959-12-30 | 1965-06-29 | Air Reduction | Krypton-xenon separation from a gas mixture |
| US3292380A (en) * | 1964-04-28 | 1966-12-20 | Coastal States Gas Producing C | Method and equipment for treating hydrocarbon gases for pressure reduction and condensate recovery |
| US3397138A (en) * | 1965-12-02 | 1968-08-13 | Warren Petroleum Corp | Gas separation employing work expansion of feed and fractionator overhead |
| US3813890A (en) * | 1969-07-02 | 1974-06-04 | B Bligh | Process of continuous distillation |
| WO2016132083A1 (en) | 2015-02-20 | 2016-08-25 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Method and apparatus for separation at sub-ambient temperature |
| FR3032889A1 (en) * | 2015-02-20 | 2016-08-26 | Air Liquide | METHOD AND APPARATUS FOR SUBAMBIAN TEMPERATURE SEPARATION |
| WO2019073132A1 (en) * | 2017-10-13 | 2019-04-18 | L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Method and device for separating air by cryogenic distillation |
| FR3072451A1 (en) * | 2017-10-13 | 2019-04-19 | L'air Liquide Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | METHOD AND APPARATUS FOR AIR SEPARATION BY CRYOGENIC DISTILLATION |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US2608070A (en) | Method and means for distillation of low boiling point liquids | |
| US4203742A (en) | Process for the recovery of ethane and heavier hydrocarbon components from methane-rich gases | |
| US3516262A (en) | Separation of gas mixtures such as methane and nitrogen mixtures | |
| US4718927A (en) | Process for the separation of C2+ hydrocarbons from natural gas | |
| US3205669A (en) | Recovery of natural gas liquids, helium concentrate, and pure nitrogen | |
| JP6416264B2 (en) | Hydrocarbon gas treatment | |
| US2122238A (en) | Process and apparatus for the separation of gas mixtures | |
| US3625017A (en) | Separation of components of hydrogen and hydrocarbon mixtures by plural distillation with heat exchange | |
| JPH08210769A (en) | Cryogenic rectification system with side column for forming low-purity oxygen | |
| US3605422A (en) | Low temperature frocess for the separation of gaseous mixtures | |
| US3327489A (en) | Method for separating gaseous mixtures | |
| JP3837182B2 (en) | Nitrogen removal method from liquefied natural gas | |
| US2552451A (en) | Fractionation of low molecular weight component mixtures | |
| JPH0552875B2 (en) | ||
| JPH04227457A (en) | Cryogenic air separating system including double temperature type supply turbo expansion | |
| US2601599A (en) | Method of recovering liquefiable hydrocarbons from gases | |
| US2692484A (en) | Separation of gaseous mixtures | |
| TW202140974A (en) | Process for cryogenic fractionation of air, air fractionation plant and integrated system composed of at least two air fractionation plants | |
| US3277655A (en) | Separation of gaseous mixtures | |
| US2713781A (en) | Variable reversible rectification process | |
| US3210948A (en) | Method for fractionating gaseous mixtures | |
| US3559417A (en) | Separation of low boiling hydrocarbons and nitrogen by fractionation with product stream heat exchange | |
| US1571461A (en) | Separation of the constituents of gaseous mixtures | |
| JPH0338519B2 (en) | ||
| US2552560A (en) | Process of producing oxygen |