Abstract: Presently disclosed is a power production plant that is operable to store and generate power. In a “charge mode” (when electricity price is low), an air separation unit (ASU) cools and liquefies ambient air into liquid oxygen (LOx), which is then stored in a storage vessel. In a “discharge mode” (when electrical price is high), the stored LOx is used by the power production plant to combust a fuel and form a combustion product stream that can be expanded in a turbine to generate power. The power production plant particularly can utilize carbon dioxide as a recycled, circulating or working fluid so that substantially all carbon dioxide produced in the power production can be captured.

Abstract: An air separation device for distilling air at a low temperature, includes a high-pressure column to separate high-pressure raw material air into high-pressure nitrogen gas and high-pressure oxygen-enriched liquefied air; a low-pressure column to separate the high-pressure oxygen-enriched liquefied air into low-pressure nitrogen gas, low-pressure liquefied oxygen, and argon-enriched liquefied oxygen; an argon column to separate the argon-enriched liquefied oxygen having a pressure higher than the pressure into argon gas and medium-pressure liquefied oxygen; first and second indirect heat-exchangers; first and second gas-liquid separation chambers; a first/second passage which communicates the gas/liquid phase of the low-pressure column and the gas phase of the second gas-liquid separation chamber; and a first/second opening/closing mechanism located on the first/second passage.

Abstract: A process for the production of a liquid oxygen stream by the cryogenic rectification of an inlet air stream, including dividing the inlet air stream into a first portion, and a second portion. Cooling the first portion, and the second portion against a cooled multicomponent refrigerant circuit, thereby producing a first cooled portion, and a second cooled portion. Condensing the first cooled portion, thereby producing a condensed first portion, then introducing the condensed first portion into one or more distillation columns. Expanding the second cooled portion in a turbo-expander, thereby producing an expanded second portion, then introducing the expanded second portion within the one or more distillation columns. Producing within the one or more distillation columns at least a waste nitrogen stream, a nitrogen enriched stream, and an oxygen enriched stream. Withdrawing the oxygen enriched stream from the one or more distillation columns as a liquid oxygen stream.

Abstract: A plate fin heat exchanger assembly (S) for a cryogenic air separation unit, comprising: a heat exchanger having at least two cryogenic liquid inlets (B,C) at least two cryogenic liquid outlets (B,C), at least one nitrogen-rich stream inlet (D) at a first end of the heat exchanger and at least one nitrogen-rich stream outlet at a second end of the heat exchanger, the heat exchanger configured to receive a flow of at least one nitrogen-rich stream (WN,LPGAN) of the air separation unit at the at least one nitrogen-rich stream inlet and separate flows of at least two cryogenic liquids (LOX,LIN,LR) at the at least two cryogenic liquid inlets; wherein the inlet of the first of the cryogenic liquids is closer to the first end than the outlet of the second of the cryogenic liquids.

Abstract: Aircraft propulsion systems include aircraft systems having at least one hydrogen tank and an aircraft-systems heat exchanger and engine systems having at least a main engine core, a high pressure pump, a hydrogen-air heat exchanger, and a turbo expander. The main engine core includes a compressor section, a combustor section having a burner, and a turbine section. Hydrogen is supplied from the at least one hydrogen tank through a hydrogen flow path, passing through the aircraft-systems heat exchanger, the high pressure pump, the hydrogen-air heat exchanger, and the turbo expander, prior to being injected into the burner for combustion. The turbo expander includes a rotor separated into a first expander portion and a second expander portion arranged about an output shaft and the output shaft is operably connected to a generator configured to generate electrical power.

Abstract: A method and apparatus for producing high-purity nitrogen and low-purity oxygen using three-column rectification are provided, in which: nitrogen and oxygen undergo rectification in different columns, with high-purity nitrogen and low-purity oxygen being separated out of air simultaneously, thereby overcoming the shortcomings of conventional low-purity oxygen production equipment, and also reducing equipment investment, lowering energy consumption, increasing product added value, and realizing a circular economy effect.

Abstract: A method of co-producing liquid hydrogen and ammonia, including a hydrogen generator, a nitrogen generator, and a HLU is presented. The method includes pressurizing a hydrogen stream from the hydrogen generator in a hydrogen compressor, dividing the pressurized hydrogen into at least a first portion and a second portion, wherein the first portion includes at least part of the flow of a first refrigeration cycle in the HLU, and the second part comprises at least part of the feed to an ammonia plant. The method also includes pressurizing a nitrogen stream from the nitrogen generator in a HP nitrogen compressor, dividing the pressurized nitrogen stream into at least a first part and a second part, wherein the first part comprises at least part of the flow of a second refrigeration cycle in the HLU, and the second part comprises at least part of the feed to the ammonia plant.

Abstract: A cryogenic air separation setup in a cold box, wherein gaseous oxygen under elevated pressure is produced through hydraulic force caused by the geodetic distance between where liquid oxygen is drawn from the distillation column and where liquid oxygen is vaporized to form gaseous oxygen, such as in an auxiliary evaporator. To increase the vertical distance between the above-mentioned two location, the components are arranged directly below one another in the following sequence: the lower-pressure column, the main condenser evaporator, the higher-pressure column, the subcooler, the main heat exchanger and the auxiliary evaporator). In particular, the main heat-exchanger is positioned with the cold-end on the top to optimize piping expenditure.

Abstract: The invention relates to a liquid air energy storage system. The storage system includes a cryocooler, a dewar, and a Sterling engine. The cryocooler cools a tip of a cold head to cryogenic temperatures, the cryocooler further includes a heat sink to reject heat from the cryocooler and a cold head that protrudes into a dewar through a cryocooler cavity, the cold head to condense ambient air to create liquified air in the dewar. The dewar holds the liquified air at low temperatures, the dewar having the cryocooler cavity and a Stirling cavity. The Stirling engine drives an electric generator, the Stirling engine further including a cold finger protruding into the dewar through the Stirling cavity, the cold finger to move the liquified air from the dewar to a Stirling heat sink; the Stirling heat sink to expand the liquified air; and the electric generator to generate output electricity.

Abstract: A nitrogen liquefier configured to be integrated with an argon and nitrogen producing cryogenic air separation unit and method of nitrogen liquefaction are provided. The integrated nitrogen liquefier and associated methods may be operated in at least three distinct modes including: (i) a nil liquid nitrogen mode; (ii) a low liquid nitrogen mode; and (iii) a high liquid nitrogen mode. The present systems and methods are further characterized in an oxygen enriched stream from the lower pressure column of the air separation unit is an oxygen enriched condensing medium used in the argon condenser.

Abstract: One aspect of the invention relates to a hydrocarbons fluid liquefaction system, having a first heat-exchange module having a pre-cooling exchanger having a pre-cooling circuit and a plurality of pre-cooling refrigerant circuits for pre-cooling the feed stream through the circulation of an expanded first mixed-refrigerant stream, and a second heat-exchange module having a liquefaction exchanger having a liquefaction circuit and a liquefaction refrigerant circuit for liquefying the feed stream through the circulation of an expanded second mixed-refrigerant stream, wherein each heat-exchange module has thermally insulating walls and a framework that allows the module to be transported and secured, and allows the first heat-exchange module to be stacked on top of the second heat-exchange module.

Abstract: Contaminants are removed from a raw natural gas stream and other types of mixed-gas streams by a separation system. The system is based on using a series of cryogenic cells, devices that can impose essentially any desired temperature and pressure conditions on a volume of incoming gas, down to cryogenic temperatures and up to multiple atmospheres of pressure. Used in succession at specific setpoints of temperature and pressure, the cryogenic cells cause gaseous contaminants in the raw gas stream to condense into liquid form, at which point, they can be separated from the stream. Flowmeters and component detectors, like mass spectrometers, are used to detect the state of the gas stream at various points in the system. The system may be divided into stages, each stage having cryogenic cells operating at different setpoints of temperature and pressure, in order to cause different contaminants to liquefy for separation.

Abstract: Disclosed in the present invention are a cold box steel structure and method for prefabricating and transporting the cold box steel structure.

Abstract: The present disclosure pertains to a system configured to generate oxygen including a compressor configured to intake and pressurize gas, an oxygen separation unit comprising a first sieve bed, a second sieve bed, and an input receiving the stream of gas from an output of the compressor. The oxygen separation unit generates an oxygen flow by separating oxygen from the stream of gas. A membrane module in fluid connection with an output of the oxygen separation unit is configured to purify the oxygen flow generated by the oxygen separation unit. A valve arrangement is configured to direct, periodically, at least some of the oxygen flow from the membrane module through the sieve beds to purge the sieve beds with retentate gas and exhaust such retentate gas. One or more processors control the valve arrangement, so as to control the oxygen flow and purging of the sieve beds.

Abstract: One object of the present invention is to provide a method for producing stable isotope labeled carbon monoxide capable of controlling the abundance ratio of a specific kind of the stable oxygen isotope to be an arbitrary value, the present invention provides a method for producing stable isotope labeled carbon monoxide including: a first mixing step in which carbon monoxide selectively containing at least one kind of stable isotope selected from the group consisting of 12C16O, 12C17O, 12C18O, 13C16O, 13C17O, and 13C18O, and water vapor selectively containing at least one kind of stable isotope selected form the group consisting of H216O, H217O and H218O are mixed to produce stable isotope labeled carbon dioxide: and a second mixing step in which the stable isotope labeled carbon dioxide produced in the first mixing step and hydrogen are mixed.

Abstract: Closed-loop refrigeration cycles for liquid oxygen densification are disclosed. The disclosed refrigeration cycles may be turbine-based refrigeration cycles or a Joule-Thompson (JT) expansion valve based refrigeration cycles and include a refrigerant or working fluid comprising a mixture of neon or helium together with nitrogen and/or oxygen.

Abstract: A compressor system is disclosed, including a first compressor unit having: at least a first gas inlet at a first gas pressure level; a second gas inlet at a second gas pressure level; and a gas discharge; a second compressor unit having: at least a third gas inlet at a third gas pressure level; a fourth gas inlet at a fourth gas pressure level; and a gas delivery. The gas discharge of the first compressor unit is fluidly coupled to one of the third gas inlet and fourth gas inlet of the second compressor unit.

Abstract: A method and apparatus serve for the cryogenic separation of air in an air separation plant which has a main air compressor, a main heat exchanger and a distillation column system with a high-pressure column and a low-pressure column. All of the feed air is compressed in the main air compressor to a first air pressure which is at least 3 bar higher than the operating pressure of the high-pressure column. A first part of the compressed total air flow, as first air flow at the first air pressure, is cooled and liquefied or pseudo-liquefied in the main heat exchanger, then expanded and introduced into the distillation column system. A second part of the compressed total air flow, as second air flow, is post-compressed in a turbine-driven post-compressor to a second air pressure.

Abstract: A nitrogen production system that can produce high purity nitrogen containing a desired concentration of oxygen and ultrahigh purity nitrogen containing a desired concentration of argon in a single rectifying column while restraining increase in electric power consumption and a production process thereof are provided. The method can include the steps of rectifying a cooled and compressed air stream in the rectifying column; withdrawing the ultrahigh purity nitrogen stream from a top portion of the nitrogen rectifying column, warming the ultrahigh purity nitrogen stream in a heat exchanger, and then recovering the ultrahigh purity nitrogen stream from the heat exchanger; and withdrawing a high purity nitrogen stream from a rectification section of the nitrogen rectifying column, warming the high purity nitrogen stream in the heat exchanger, and then recovering the high purity nitrogen stream from the heat exchanger.

Abstract: A fuel cell system using natural gas, which includes a fuel cell including a cathode and an anode and a cryogenic heat-exchanging apparatus configured to heat-exchange natural gas supplied from a natural gas station with introduced air or exhaust gas of the fuel cell. With the configuration, oxygen which is introduced into the fuel cell can be produced using cold energy of the natural gas, and energy consumed for the oxygen production can be reduced. Also, a discharge of seawater of low temperature can be minimized, thereby reducing negative effects caused by the discharge.

Abstract: Method and device for generating gaseous compressed nitrogen by the low-temperature separation of air in a distillation column system, having a pre-column, a high-pressure column and a low-pressure column. The feed air is compressed, purified in a purification apparatus and cooled. A first sub-flow of the cooled feed air is introduced in a predominantly liquid state into the distillation column system. A gaseous fraction from the pre-column in introduced into the liquefaction chamber of a pre-column head condenser with liquid formed therein fed as reflux into the pre-column. A first gaseous nitrogen product fraction is drawn from the high-pressure column, heated, and obtained as first gaseous compressed nitrogen product. At least a part of the second sub-flow is introduced into the evaporation chamber of the pre-column head condenser. A third sub-flow of the cooled feed air is expanded to perform work and subsequently introduced into the liquefaction chamber.

Abstract: A method for producing liquefied natural gas (LNG) from a natural gas stream having a nitrogen concentration of greater than 1 mol %. At least one liquid nitrogen (LIN) stream is received at an LNG liquefaction facility. The LIN streams may be produced at a different geographic location from the LNG liquefaction facility. A natural gas stream is liquefied by indirect heat exchange with a nitrogen vent stream to form a pressurized LNG stream. The pressurized LNG stream has a nitrogen concentration of greater than 1 mol %. The pressurized LNG stream is directed to one or more stages of a column to produce an LNG stream and the nitrogen vent stream. The column has upper stages and lower stages. The LIN streams are directed to one or more upper stages of the column.

Abstract: An apparatus for the distillation of air by cryogenic distillation is provided. The apparatus can include an enclosure; a first distillation column configured to operate at a first pressure; a second distillation column configured to operate at a second pressure that is lower than the first pressure, the second distillation column being placed above the first distillation column and forming therewith a double column; a subcooling heat exchanger configured to cool at least one liquid from the first distillation column upstream of the second distillation column and configured to warm a gaseous nitrogen stream from the second distillation column; and an argon column configured to separate an argon enriched stream from the second distillation column and configured to produce an argon rich stream.

Abstract: Systems and methods for multi-stage refrigeration in mixed refrigerant and cascade refrigeration cycles using one or more liquid motive eductors in combination with a pump.

Abstract: A turbomachine arrangement includes a housing, a turbo-expander formed with an expander rotor, a turbo-compressor formed with a first compressor rotor, and a shaft that is rotatably mounted on the housing. The shaft connects the expander rotor to the compressor rotor. The first turbo-compressor can be driven exclusively by the turbo-expander. A second turbo-compressor having a second compressor rotor is disposed on the housing such that the second compressor rotor is connected to the first turbo-compressor in parallel or in series. The second compressor rotor is driven via a transmission accommodated in the housing and via a drive shaft connecting the transmission to the second compressor rotor.

Abstract: An apparatus for the production of air gases with variable liquid production by the cryogenic separation of air can include a cold box having a heat exchanger, and a system of columns; a pressure monitoring device; and a controller. The cold box can be configured to receive a purified and compressed air stream under conditions effective for cryogenically separating the air stream to form an air gas product. The apparatus may also include means for transferring the air gas product from the cold box to an air gas pipeline. The pressure monitoring device is configured to monitor the pipeline pressure, and the controller is configured to adjust the product pressure of the air gas product coming out of the cold box based upon the pipeline pressure and to further adjust liquid production from the cold box based on the adjusted product pressure.

Abstract: In a process for separating at least one “heavy” impurity such as hydrogen sulfide from crude carbon dioxide comprising significant quantities of at least one “light” impurity such as non-condensable gases, involving at least one heat pump cycle using carbon dioxide-containing fluid from the process as the working fluid, the “light” impurity is removed from the crude carbon dioxide and carbon dioxide is subsequently recovered from the removed “light” impurity, thereby improving overall carbon dioxide recovery and efficiency in terms of energy consumption.

Abstract: Various embodiments relate to combined heat and power (CHP) systems. A CHP system can include a turbine system, a turbocharger system, and a refrigeration system. The refrigeration system can receive combustion products from the turbine system and compressed air from the turbocharger system. The refrigeration system can cool the combustion products and the compressed air to generate a cooled combustion product mixture that is provided to the turbine system.

Abstract: A method and apparatus for argon recovery in which an impure argon stream is separated from air within a cryogenic air separation unit having an argon rejection column and a reflux type argon condenser disposed internally within the lower pressure column. An impure argon stream is subsequently recovered from the argon rejection column and purified within an integrated adsorbent based argon refining and purification subsystem to produce product grade argon. The waste stream from the adsorbent based argon refining and purification subsystem is recycled back to the argon rejection column so as to improve the argon recovery.

Abstract: A method and apparatus for argon rejection and recovery in which argon is separated from air within a cryogenic air separation plant having a divided wall argon rejection column arrangement and condensed using an argon condenser disposed internally within the lower pressure column. The divided wall argon rejection column arrangement may be an annular arrangement or a side-by-side arrangement (i.e. segmented or planar configuration). The resulting argon stream is subsequently rejected or recovered and optionally purified within an integrated adsorbent based argon refining and purification subsystem to produce product grade argon.

Abstract: An arrangement of insulation within a container to prevent heat leakage from the ambient to an apparatus located within the container that operates at a cryogenic temperature. The arrangement of insulation includes bulk insulation filling the container and an insulation layer that is located within the container, between the apparatus and the container. The insulation layer as opposed to the bulk insulation has a lower thermal conductivity. An exterior region of the apparatus is situated closer to an opposite container wall region of the container than remaining exterior regions of the apparatus. The insulation layer is sized to only insulate the exterior region of the apparatus from heat leakage from the opposite container wall region. The insulation layer can be formed of an aerogel.

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

Abstract: A method and apparatus for argon recovery in which an impure argon stream is separated from air within a cryogenic air separation unit having a divided wall argon rejection/rectification column. The resulting argon stream is subsequently recovered and purified within an integrated pressure swing adsorption system to produce product grade argon.

Abstract: An apparatus for separating air by cryogenic distillation comprises N air compressors (C1, C2, C3) connected so as to receive air at ambient pressure and designed to produce air at a first pressure above 12 bar absolute, N being at least 3, each of the compressors being driven by a single asynchronous motor (M1, M2, M3), the total power of the compressors being at least 10 MW.

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

Abstract: A method and an apparatus for producing carbon dioxide by cryogenic distillation is provided.

Abstract: Separation method and apparatus for separating a gaseous mixture, for example, air, in a cryogenic rectification plant in which a compressed stream is divided into subsidiary streams that are extracted from a main heat exchanger of the plant at higher and lower temperatures. The two streams are then combined and expanded in a turboexpander to generate refrigeration for the plant. The flow rates of the two streams are adjusted to control inlet temperature of a turboexpander supplying plant refrigeration and to minimize potential deviation of the turboexpander exhaust from a saturated vapor state. Control of the expansion ratio can advantageously be applied to allow variable liquid production from the rectification plant.

Abstract: The invention relates to a method for air separation by cryogenic distillation in a column system that includes at least a first column operating at a first pressure, and a second column operating at a second pressure that is lower than the first pressure, the head of the first column being thermally connected to the tank of the second column via a vaporizer-condenser, a first portion of a nitrogen-enriched gas is drawn from the head of the first column, compressed in a compressor having an inlet temperature no higher than ?150° C. and condensed in the vaporizer-condenser, an oxygen-rich fluid is drawn from the lower portion of the second column and heated in the exchange line, a nitrogen-rich gas is drawn from the upper portion of the second column and heated in the exchange line, and a second portion of the nitrogen-enriched gas is expanded in a turbine without being compressed.

Abstract: The method and the apparatus are used for the low-temperature fractionation of a fluid mixture. The fluid mixture is introduced into a separation column. At least a portion of the sump liquid from the separation column is introduced into a sump evaporator and at least partly evaporated there. At least a portion of the vapor produced in the sump evaporator is led back into a lower section of the separation column. A top product is removed at the top of the separation column, and a sump product is removed from the sump of the separation column or from the sump evaporator. The sump evaporator is operated by means of inductive heating.

Abstract: A cryogenic insulation system is proposed comprising enclosing at least a portion of a cryogenic device with low density high conductivity insulation material. The cryogenic device may be an air separation unit. The cryogenic device does not include an outer containment structure for granulated cryogenic insulation. The low density high conductivity insulation material may consists of at least one layer of abutting or overlapping low density high conductivity insulation material composite with fibrous batting. The portion of the cryogenic device is selected from the group consisting of: a distillation column, a heat exchanger, a condenser, a reboiler, an expansion turbine, valves, piping, or any combination thereof.

Abstract: The invention relates to a transportable package for a low-temperature air separation plant which has a main heat exchanger (2a, 2b, 2c) for cooling feed air (1) and a double column (5) for separating the cooled feed air, wherein the double column (5) has a high-pressure column and a low-pressure column that are arranged above one another. The transportable package has a cold box (20, 400), in the interior of which accessories of the double column (5), in particular pipelines (7, 11, 12) and valves, are arranged, but not the double column and not the main heat exchanger, wherein the transportable package has connections for joining the pipelines to the double column and to the main heat exchanger. Moreover the invention relates to a low-temperature air separation plant and to a method for producing a low-temperature air separation plant using this transportable package.

Abstract: A method of producing at least one air gas using cryogenic distillation is provided. The expanded streams coming from the two turbines are combined and then split into two fractions. The first fraction is sent to the medium-pressure column of the system in gaseous form, whereas the second fraction is returned to the cold end of the heat exchange line. At a temperature T4 below ?100° C. and above T2, the second fraction is sent to a turbine where it expands up to a temperature T5, forming an air stream. This air stream is then warmed in the heat exchange line before being discharged into the atmosphere, so that the distillation is not disturbed. A liquid product is withdrawn from the column system as final product. The sole liquid product from the apparatus is liquid oxygen, but of course other products may be produced.

Abstract: The invention relates to a transportable package with a cold box, in the interior of which at least one double column of a low-temperature air separation system is arranged, i.e., a double column having a high-pressure column and a low-pressure column. The high-pressure and low-pressure columns contain mass transferring elements. The mass transferring elements in at least one sub-region of the low-pressure columns are formed by an ordered packing made of folded metal sheets having a thickness of 0.2 mm or less. The ordered packing has a specified surface area of at least 1000 m2/m3. At least in a sub-region of the high-pressure column, the mass transferring elements are formed by rectifying plates arranged one over the other and which have a clearance of less than 195 mm. The invention further relates to a method for producing a low-temperature air separation system using such a transportable package.

Abstract: A method and apparatus for separating air in which an argon refining column of a distillation column system is reboiled with a liquid air stream. The argon refining column further refines crude argon produced by a crude argon column connected to a lower pressure column of the distillation column system. At least one intermediate reflux stream is formed, at least indirectly, from at least part of the liquid air stream, and is introduced into the lower pressure column at a level thereof above where a crude liquid oxygen column bottoms of a higher pressure column of such system is further refined to increase a liquid to vapor ratio below said level and therefore, argon recovery from the argon refining column.

Abstract: A method and apparatus for separating air in which an argon refining column of a distillation column system is reboiled with a liquid air stream. The argon refining column further refines crude argon produced by a crude argon column connected to a lower pressure column of the distillation column system. At least one intermediate reflux stream is formed, at least indirectly, from at least part of the liquid air stream, and is introduced into the lower pressure column at a level thereof above where a crude liquid oxygen column bottoms of a higher pressure column of such system is further refined to increase a liquid to vapor ratio below said level and therefore, argon recovery from the argon refining column.

Abstract: An apparatus for separating air by cryogenic distillation comprises N air compressors (C1, C2, C3) connected so as to receive air at ambient pressure and designed to produce air at a first pressure above 12 bar absolute, N being at least 3, each of the compressors being driven by a single asynchronous motor (M1, M2, M3), the total power of the compressors being at least 10 MW.

Abstract: In a method for producing an apparatus for air separation by cryogenic distillation, at least one gas in the air is obtained as a product by air separation in a cold box including at least one column, the cold box being supplied with air at a first pressure by N air compressors that compress the air from the ambient pressure to the first pressure, the first pressure being greater than 12 bar absolute and less than 35 bar absolute, N being equal to or greater than 3, and the total power of the N compressors being greater than 10 MW, a group of n size classes of a frame for compressors being predefined, n being equal to 2 or 3 or 4 or 5, and the N compressors being selected such that all of the N compressors have a size selected from the n sizes of the group.

Abstract: A method and apparatus for separating air in which an argon refining column of a distillation column system is reboiled with a liquid air stream. The argon refining column further refines crude argon produced by a crude argon column connected to a lower pressure column of the distillation column system. At least one intermediate reflux stream is formed, at least indirectly, from at least part of the liquid air stream, and is introduced into the lower pressure column at a level thereof above where a crude liquid oxygen column bottoms of a higher pressure column of such system is further refined to increase a liquid to vapor ratio below said level and therefore, argon recovery from the argon refining column.

Abstract: An apparatus for the separation of air by cryogenic distillation comprises a column system including a double column, an intermediate pressure column, and an argon column having a top condenser, a heat exchanger, means for pressurizing and vaporizing oxygen rich liquid and nitrogen rich liquid from the double column, conduits configured to: send argon enriched gas from the low pressure column to the argon column, remove argon rich fluid from the top of the argon column, send a liquid air stream at least in part to a top condenser of the intermediate pressure column where it is partially vaporized to form a vapor and a liquid, send the vapor formed in the top condenser of the intermediate pressure column to the low pressure column, and send the liquid from the top condenser of the intermediate pressure column to the intermediate pressure column to be separated.

Abstract: An installation for separating air by cryogenic distillation comprises a compressor, a heat-exchange line, a system of columns, an electric motor for driving the compressor, a pipe for taking off a liquid from the system of columns, a pump for pressurising the liquid drawn off and means for affording an exchange of heat between the air compressed by the compressor and the liquid pressurised by the pump and means for reducing the output pressure of the pump according to the frequency of the electricity supplying the electric motor.