Abstract: Air is separated by rectification. The air is compressed in a main air compressor to a first pressure. Without further compression a first flow of the compressed air is cooled in a main heat exchanger to a temperature suitable for its separation by rectification. The first flow is introduced into the higher pressure column of a double rectification column comprising, in addition to the higher pressure column, a lower pressure column, in which a bottom oxygen fraction containing from about 50 to about 96 mole percent of oxygen is formed. A condenser-reboiler places the higher pressure column in heat exchange relationship with the lower pressure rectification column. A second flow of the compressed air is expanded with the performance of external work in an expansion turbine without further compression of the second flow upstream of the expansion. The expanded second flow is introduced into the lower pressure rectification column. An impure oxygen product is taken from the said bottom fraction.

Abstract: In this installation (1) for the distillation of air in a double column, the low pressure column and the medium pressure column are disposed side by side and the base of the low pressure column (3) is above the base of the medium pressure column (2). The low pressure column is disposed above an element for confining a cryogenic fluid which can be a mixing column (5), an argon column, a column operating at a pressure intermediate the medium pressure and the low pressure, a storage (32) or an exchanger.

Abstract: The combined plant comprises at least one furnace (FM) fed by a blowing machine (S), at least one air distillation device containing at least one medium-pressure column (MP) and a mixing column (CM) which has an oxygen outlet line (O) to feed the furnace (FM), the distillation device being fed via the blowing engine (S), at least the compressed air directed to the mixing column (CM) being given a positive pressure in at least one compressor-turbine group (C2-T2), the turbine (T2) of which is located in a circuit (Fi) for a pressurized fluid which is available at the plant site, for example steam or a gas originating from the furnace.

Abstract: The present invention relates to processes and installations for the production of oxygen and nitrogen by cryogenic distillation. The cost of oxygen and nitrogen production is reduced by providing an improved high pressure process.

Abstract: A system for generating refrigeration and providing the refrigeration into a cryogenic rectification plant wherein, in addition to refrigeration generated by turboexpansion, further refrigeration for the plant is generated by a recirculating multicomponent refrigerant in a refrigeration circuit.

Abstract: Air is distilled in a single column (8) installed on a boat, and from here an oxygen-enriched liquid flow is drawn-off. This flow is pressurized by a pump (9) and vaporized by heat exchange with air or nitrogen. The oxygen (105) is used for the partial oxidation of a flow (101) containing hydrocarbons, for example natural gas.

Abstract: The combined plant comprises at least one furnace (F), at least one air distillation device containing at least one medium-pressure column (MP) and a mixing column (CM) which has an oxygen outlet line (O) for supply to the furnace (F), at least one blowing engine (S) which feeds at least the furnace (F) and the medium-pressure column (MP), and at least one air compressor (C) which supplies at least the mixing column (CM) with air at a pressure which is greater than the pressure of the air supplied by the blowing engine (S).

Abstract: A method and apparatus for separating out is used to produce an oxygen product in which an air stream after having been compressed and purified is introduced into a bottom reblower located in a bottom region of the distillation column to produce boil up in such distillation column. The resultant air stream liquefies to produce a liquid air stream. The liquid air stream after having been valve expanded is stripped within the distillation column to produce a column bottoms which can be extracted as a product stream that is vaporized within a main heat exchanger. Product stream can be pressurized by being pumped to atmospheric a pressure hence liquefying a further compressed air stream to produce further liquid air is also stripped within the distillation column. The distillation column operates at near atmospheric pressures that is pressures between 1 and 1.3 bar absolute. Refrigeration is introduced into the plant by injecting liquid preferably liquid oxygen into a bottom region of the distillation column.

Abstract: A double rectification column air separation method and apparatus in which a stream of oxygen-enriched liquid air from a higher pressure rectification column is at least partially vaporized in indirect heat exchange with a stream of purified, compressed, gaseous air. The stream of purified, compressed air is condensed and a stream of the resulting vapor after having been warmed is expanded in a turbine with the performance of external work. After expansion, the resulting vapor is introduced into the lower pressure rectification column and a stream of the resulting condensed air is introduced into the higher pressure column at an intermediate mass exchange level thereof.

Abstract: A method for low temperature separation of fluids wherein the separation process is sustained by refrigeration generated by a recirculating multicomponent refrigerant fluid.

Abstract: The air coming from a blowing turbine (13) and intended for the low-pressure column of a double column (2) is cooled by indirect heat exchange with a liquid (15, 20). This liquid is a purge stream from a condenser (5, 6) of the system.

Abstract: A blast furnace (1) is supplied with a flow of optionally oxygen-enriched air coming from an isothermal compressor (3) or a (radial) centrifugal compressor (11).

Abstract: A cryogenic air separation system wherein a portion of the feed air is compressed to a very high pressure, bypasses the primary heat exchanger, and is turboexpanded to a low pressure to supply refrigeration in one step from the warm end temperature to the cryogenic temperature of the cryogenic air separation plant.

Abstract: The present invention relates to a process for the cryogenic distillation of air in a distillation column system that contains at least one distillation column wherein the boil-up at the bottom of the distillation column producing the oxygen product is provided by condensing a stream whose nitrogen concentration is equal to or greater than that in the feed air stream. The process of the present invention comprises the steps of: (a) generating work energy which is at least ten percent (10%) of the overall refrigeration demand of the distillation column system; (b) work expanding a process stream to produce additional work energy such that the total work generated along with step (a) exceeds the total refrigeration demand of the cryogenic plant; and (c) using the work which is generated in excess of the refrigeration need of the distillation column system to cold compress a process stream at a temperature lower than the ambient temperature.

Abstract: A double column cryogenic air separation system is operated to increase boilup in the lower pressure column by vaporizing at an intermediate pressure a liquid stream containing at least 20 mole % oxygen, work expanding the stream, and introducing the resulting expanded stream into the lower pressure column. Operation in this mode increases oxygen recovery at a given rate of compressed and purified air feed or reduces the amount air feed required to produce a given rate of oxygen product. Argon recovery can be integrated efficiently with the intermediate pressure vaporization and work expansion steps.

Abstract: The present invention relates to a process for the cryogenic distillation of air in a distillation column system that contains at least one distillation column wherein the boil-up at the bottom of the distillation column producing the oxygen product is provided by condensing a stream whose nitrogen concentration is equal to or greater than that in the feed air stream, which comprises the steps of: (a) generating work energy which is at least ten percent (10%) of the overall refrigeration demand of the distillation column system by at least one of the following two methods: (1) work expanding a first process stream with nitrogen content equal to or greater than that in the feed air and then condensing at least a portion of the expanded stream by latent heat exchange with at least one of the two liquids: (i) a liquid at an intermediate height in the distillation column producing oxygen product and (ii) one of the liquid feeds to this distillation column having an oxygen concentration equal to or preferably grea

Abstract: Feed air is fed to a rectifying system (14, 15) for low-temperature separation, from which a liquid fraction (31, 32) is taken off and introduced into a first reservoir tank (33). The pressure of a variable rate of the liquid fraction (34) is increased (35). The liquid fraction (36) is evaporated under the elevated pressure by indirect heat exchange (12) and obtained as a gaseous pressurized product (37). A heat-transport medium circulates in a refrigeration cycle which has a cycle compressor (41, 42). A first partial stream (45) of the heat-transport medium (44) compressed in the cycle compressor (41, 42) is fed to the indirect heat exchange (12) to evaporate the liquid fraction (36) and is liquefied, at least in part, in the course of this. A second partial stream (59) of the heat-transport medium (44) compressed in the cycle compressor (41, 42) is expanded (43) so as to perform work. Liquefied heat-transport medium (45, 48) is buffered in a second reservoir tank (49).

Abstract: A method and apparatus for separating air to produce an oxygen product in which air is separated within a double column arrangement. In the double column arrangement part of the air to be separated reboils a lower pressure column and is then introduced into the higher pressure column for separation. Another part of the air is partially cooled and then expanded with the performance of work and then introduced into the lower pressure column to supply part of the refrigeration requirements. The remaining part of the refrigeration requirements is supplied by partially vaporizing a crude liquid oxygen stream within a head condenser used to produce reflux for the higher and lower pressure columns. The partially vaporized stream is then phase separated into liquid and vapor phases. The liquid phase is introduced into the lower pressure column and the vapor stream after having been partially warmed is turboexpanded to provide the remaining refrigeration requirements of the plant.

Abstract: A dual feed pressure cryogenic air separation system wherein all the feed air is pressurized to an intermediate pressure and cleaned of high boiling impurities at that intermediate pressure, and a portion further compressed to the high pressure and then cooled against another portion so as to prepare that other portion for the turboexpansion to the low pressure, preferably with the turboexpansion driving the further compression.

Abstract: The present invention is an improvement to a nitrogen generator enabling the process to efficiently coproduce oxygen with low recovery, typically less than 70% and preferably less than 55%, in addition to the primary product, nitrogen. In the nitrogen generator process, air is distilled in a distillation column system having a higher pressure column and a lower pressure column. The feed air is compressed, treated to remove water and carbon dioxide, cooled to near its dew point and fed to the higher pressure column of the distillation column system. The nitrogen product is produced by removing an overhead vapor stream from at least one of the columns of the distillation column system. At least one oxygen-enriched stream is removed from the lower pressure column.

Abstract: A system for the production of ultra-high purity nitrogen and ultra-high purity oxygen at high recovery by the cryogenic rectification of feed air employing a main column, an auxiliary column and a stripping column, wherein the stripping column is driven by main column kettle fluid and additional process fluid generated in the auxiliary column is utilized in the main column.

Abstract: A cryogenic rectification system wherein low purity oxygen is recovered from a side column or the lower pressure column of a double column while a portion of the low purity oxygen is fed to an auxiliary column driven by fluid having a high nitrogen concentration wherein high purity oxygen is produced.

Abstract: The present invention relates to a process for the cryogenic distillation of air in a distillation column system having at least one distillation column operating at a higher pressure and one distillation column operating at a lower pressure, wherein feed air is cooled and fed to the higher pressure column, wherein the boil-up at the bottom of the lower pressure column producing the oxygen product is provided by condensing a stream having a nitrogen concentration equal to or greater than that of the feed air stream and wherein at least two expanders are employed to provide refrigeration to the distillation column system, wherein the first expander is operated at an inlet temperature near ambient or above ambient temperature and the second expander is operated at an inlet temperature colder than ambient, characterized in that at least one of the two expanders employs at least one of the following steps: (a) work expanding a portion of the feed air; (b) work expanding a process stream with a nitrogen content eq

Abstract: A serial column system for producing relatively large quantities of both high purity nitrogen gas and high purity nitrogen liquid using a first column producing the high purity gas and a second column producing the high purity liquid, with second column top fluid refluxing the first column.

Abstract: A process and plant for air separation by cryogenic distillation. Air is cooled in a main exchanger and is sent to a distillation column in which it separates into an oxygen-enriched liquid and a nitrogen-enriched vapor. A stream of pressurized liquid coming from the apparatus vaporizes in the main exchanger. The refrigeration necessary for the process is generated by expansion of air in one or more turbines immediately downstream of the main exchanger. The turbine or turbines produces or produce, as output, a stream which is at least 95 percent liquid, preferably 100 percent liquid.

Abstract: A cryogenic air separation system wherein base load pressure energy is supplied to the feed air by a base load compressor and custom load pressure energy is supplied to the feed air by a bridge machine having one or more turbine booster compressors and one or more product boiler booster compressors, all of the compressors of the bridge machine driven by power supplied through a single gear case.

Abstract: A cryogenic rectification system wherein a product boiler is incorporated into the primary heat exchanger without encountering boiling to dryness problems wherein liquid from the cryogenic rectification plant is processed in a phase separator upstream of the product boiler, and fluid from the product boiler is passed into the phase separator prior to recovery.

Abstract: In a process for the cryogenic distillation of air in a distillation column system that contains at least one distillation column wherein the boil-up at the bottom of the distillation column producing the oxygen product is provided by condensing a stream whose nitrogen concentration is equal to or greater than that in the feed air stream, which comprises the steps of: (a) generating work energy which is in excess of the overall refrigeration demand of the distillation column system by at least one of the following three methods: (1) work expanding a first process stream with nitrogen content equal to or greater than that in the feed air and then condensing at least a portion of the expanded stream by latent heat exchange with at least one of the two liquids: (i) a liquid at an intermediate height in the distillation column producing oxygen product and (ii) one of the liquid feeds to this distillation column having an oxygen concentration equal to or preferably greater than the concentration of oxygen in the f

Abstract: Air is separated in a double rectification column comprising a higher pressure rectification column, a lower pressure rectification column and a condenser-reboiler placing the higher pressure rectification column in heat exchange relationship with the lower pressure rectification column. At least one stream of air is introduced into the double rectification column, a stream of pressurized liquid comprising oxygen and nitrogen is reduced in pressure by passage through a valve and is partially or totally vaporized in a vaporizer-condenser, a stream of resulting vapor from the partial or total vaporization is compressed in a compressor at cryogenic temperature and is introduced into the double rectification column, and an oxygen produce is withdrawn from the lower pressure rectification column through an outlet.

Abstract: A cryogenic rectification plant comprising a double column and a side column having a bottom reboiler wherein feed air is passed into the double column by way of the bottom reboiler and an auxiliary compressor is connected in parallel with the feed air line.

Abstract: A cryogenic rectification system for the separation of feed air wherein at least some of the feed air is liquefied upstream of the separation columns, all of the liquefied feed air is introduced into a higher pressure column, and then a portion of this liquefied feed air is withdrawn from the higher pressure column and in serial fashion introduced into a lower pressure column.

Abstract: A cryogenic rectification system for producing lower purity oxygen comprising a double column with a third column reboiled by feed air at an intermediate level and, optionally, in a staged manner at the bottom level.

Abstract: A cryogenic rectification system for producing high pressure oxygen wherein a portion of the feed air is condensed by indirect heat exchange with pressurized liquid oxygen and then passed, preferably after subcooling, into the lower pressure column of a double column system.

Abstract: The process and the apparatus are used for low-temperature separation of air in a rectifying column system that has a preliminary separation column (10) and a low-pressure column (20). Feed air (1, 3) is introduced (4, 6, 7, 8, 41) into preliminary separation column (10) and is separated into a nitrogen-enriched overhead fraction and an oxygen-enriched bottom fraction. At least a portion (19) of the oxygen-enriched bottom fraction is introduced into the low-pressure column (20), in which liquid oxygen and gaseous nitrogen are produced. The pressure in preliminary separation column (10) is essentially equal to the pressure of low-pressure column (20). The reflux for the columns can be obtained by one or two cyclic processes operated with overhead gas (11, 23) from one or two columns (10, 20).

Abstract: An air separation method and apparatus in which a flow of air is subjected to a first rectification so as to separate therefrom an oxygen fraction and a nitrogen fraction. An argon-containing stream comprising argon, oxygen, and, as an impurity, nitrogen is withdrawn from the first rectification and is subjected to a second rectification so as to separate an impure argon fraction containing nitrogen. Nitrogen impurity is stripped from a stream of the argon fraction in a stripping column. A stream of sub-cooled liquid cools a condenser associated with an upper region of the stripping column by indirect heat exchange with condensing argon-nitrogen vapor mixture, and passes out of said indirect heat exchange still in sub-cooled state.

Abstract: Air is compressed in an arrangement of compressors. A first flow of the thus compressed air flows through a main heat exchanger from its warm end to its cold end and is liquefied by passage through a valve. Two second stream of compressed air are taken. One is expanded in one expansion turbine and the other in another expansion turbine. The streams leaving the valve and the one expansion turbine are separated in a double rectification column. Liquid oxygen product is extracted from outlet thereof. Part is taken as liquid product and the rest is vaporized by passage through the heat exchanger from its cold end to its warm end and taken as gaseous oxygen product. The ratio of liquid oxygen product to total oxygen product is capable of being varied. Accordingly a chosen but variable proportion of the two second air streams flows to the double rectification column and a chosen but variable proportion of the two second air streams is returned to the arrangement of compressors to an intermediate compressor.

Abstract: A cryogenic rectification system for producing low purity oxygen and high purity oxygen employing an offset dual column with bottom reboil of the lower pressure column effected by condensing feed air, with intermediate reboil of the lower pressure column effected by condensing higher pressure column top vapor, and with waste nitrogen turboexpansion to generate refrigeration.

Abstract: A cryogenic rectification system wherein feed air is turboexpanded to generate refrigeration through two turboexpanders operating at the same inlet pressure but at different inlet temperatures enabling the turboexpanders to efficiently drive the compressor or compressors which compress the feed air to the single expansion pressure.

Abstract: A cryogenic air separation system wherein higher pressure column kettle liquid is divided into a portion introduced directly into the lower pressure and a portion which is substantially completely vaporized to drive an argon column top condenser, enabling the vaporization of elevated pressure liquid oxygen against feed air while maximizing argon recovery.

Abstract: A cryogenic rectification system for processing feed air wherein a defined large flow of high pressure nitrogen shelf vapor is recovered directly from the higher pressure column of a double column, pressurized oxygen liquid is vaporized to produce high pressure oxygen product against a portion of the feed air, and the resulting condensed feed air portion is split in a defined manner and fed into each of the higher and lower pressure columns of the double column.

Abstract: The present invention relates to an air liquefaction separation apparatus whose power cost is reduced. A low-pressure column of a double rectification column has a cleaning section at a lower position, and a liquid oxygen is partly withdrawn from the space above the cleaning section so as to supply it to a main condenser-evaporator. The liquid oxygen supplied to the main condenser-evaporator is subjected to heat exchange with a nitrogen gas separated at the head of a high-pressure column to be gasified into an oxygen gas. This oxygen gas is introduced to the space under the cleaning section. Hydrocarbons contained in the oxygen gas ascending through the cleaning section are removed by the rest of the liquid oxygen descending through the cleaning section to provide a clean oxygen gas. The liquid oxygen passed through the cleaning section is withdrawn from the low-pressure column.

Abstract: A cryogenic air separation system wherein feed air is compressed in a multistage primary air compressor, a first part is turboexpanded and fed into a cryogenic air separation plant, and a second part is turboexpanded and at least a portion of the turboexpanded second part is recycled to the primary air compressor at an interstage position.

Abstract: A process and a plant in which gaseous oxygen is produced directly at the desired high pressure by pumping liquid oxygen drawn off in the vessel of the low-pressure column (11). The air to be distilled is split into three flows: a flow at the medium pressure of the double distillation column (1), a flow at a high pressure, higher than approximately 60 bars, and a flow at an intermediate pressure which, after partial cooling, is expanded to the medium pressure in a turbine (8). The intermediate pressure is chosen so that the air treated in the turbine is near its dew point at the entry of the turbine wheel. Liquid product is simultaneously drawn off (at 24) from the plant.

Abstract: The process and apparatus are based on a triple-column system, having at least a high-pressure column (7), a medium-pressure column (8) and a low-pressure column (9). Feed air (1) is compressed to a first pressure (2). A first partial stream (101, 103, 104) of the resultant air feed (3) is sent into high-pressure column (7) after it has been compressed to a second pressure (5, 102), which is at least equal to the operating pressure of the high-pressure column (7). A second partial stream (201, 202) of the compressed air feed (3) is fed into the medium-pressure column (8). A third partial stream (301, 303, 304) of the compressed air feed (3) is engine-expanded (305) and then fed (306) into the low-pressure column (9). Fractions (18; 26) from the high-pressure column (7) and the medium-pressure column (8) are introduced at least partially into low-pressure column (19, 20; 28, 29). Nitrogen-enriched top fractions (10; 21) from high-pressure column (7) and medium-pressure column (8) are condensed (11; 22).

Abstract: Air is compressed in a compressor, pre-purified in an unit, and cooled in a heat exchanger. The resulting flow of air is subjected to a first rectification in a double rectification column so as to separate the air into an oxygen-rich fraction and a nitrogen-rich fraction. A further oxygen fraction, enriched in argon, is withdrawn from the double rectification column and is introduced into the bottom of a second rectification column in which relatively pure argon is separated from the oxygen. A stream of relatively impure argon is supplied from an independent source to an intermediate region of the second rectification column through an inlet thereof.

Abstract: An integrated gasification combined cycle (IGCC) power generation system is operated with a cryogenic air separation system which produces oxygen used in a gasification system to produce fuel gas for the IGCC combustion turbine and pressurized nitrogen which is introduced into the combustor for control of nitrogen oxides and increased combustion turbine output. The air separation system produces argon as an additional product, and the air separation system preferably operates in the feed pressure range of about 100 to about 160 psia. The compressed air feed for the air separation system and the compressed combustion air for the IGCC system are provided independently in separate compression steps.

Abstract: Cooled and purified air is introduced into a higher pressure rectification column and separated into oxygen-enriched liquid and nitrogen vapour. A stream of the oxygen-enriched liquid is flashed through a pressure reducing valve to form a mixture of liquid further enriched in oxygen and vapour depleted of oxygen. The liquid is reboiled by reboiler. A stream of the further enriched liquid is reboiled in condenser and is introduced into a lower pressure rectification column for separation into oxygen and nitrogen products. Reflux for the columns and is formed by condensing in condenser nitrogen vapour separated in the higher pressure rectification column. A reboiler provides an upward flow of vapour through the column. The condenser and reboiler take the form of a single heat exchanger. The reboiler is located in a phase separator, the reboiler is located in a rectification column containing liquid-vapour contact devices above the level at which fluid issuing from the valve is introduced.

Abstract: An air separation process and apparatus employing a single column nitrogen generator. Part of the incoming air stream to be separated is expanded and combined with a waste stream. After partial warming of the combined stream, the combined stream is expanded and then utilized to liquefy part of the incoming air and for refrigeration purposes.

Abstract: A process is set forth for the cryogenic distillation of an air feed to produce an oxygen product, particularly an oxygen product at moderate purity (80-99%, preferably 85-95%). The process uses an auxiliary low pressure column in addition to the conventional high pressure column and low pressure column. The auxiliary low pressure column, which is preferably operated at the same pressure as the main low pressure column and which is heat integrated with the top of the high pressure column by means of its bottom reboiler/condenser, pretreats the crude liquid oxygen from the bottom of the high pressure column. The resulting overhead vapor stream and bottom stream are subsequently fed to the main low pressure column. Preferably, the bottom stream is fed to the main low pressure column in a state which is at least partially vapor.

Abstract: Air is separated in a higher pressure rectification column into a bottom fraction of oxygen-enriched liquid air and a top fraction of nitrogen. The column has a first inlet for a first vaporous air stream at a first pressure communicating with an expansion turbine. A first condenser-reboiler for condensing a second vaporous air stream at a second pressure greater than the first pressure has an inlet communicating with a compressor. The condensate flows through an expansion valve into the higher pressure rectification column. A stream of oxygen-enriched liquid is withdrawn from the bottom of the column and is introduced into a lower pressure rectification column in which an impure oxygen fraction is separated. A second condenser-reboiler places the top of the higher pressure rectification column in heat exchange relationship with an intermediate region of the column. Reboil for the bottom of the column is provided by the first condenser-reboiler. An impure oxygen product is withdrawn from the column.