Abstract: A moderate pressure, argon and nitrogen producing cryogenic air separation unit and air separation cycle having a higher pressure column, a lower pressure column and an argon column arrangement is disclosed. The moderate pressure, argon and nitrogen producing cryogenic air separation unit is configured to take a first portion of an oxygen enriched stream from the lower pressure column, which together with an external source of liquid nitrogen is used as the boiling side refrigerant to condense the argon in the argon condenser. Use of the external source of liquid nitrogen in the argon condenser allows a second portion of the oxygen enriched stream from the lower pressure column to be taken as a liquid oxygen product stream.

Abstract: A moderate pressure air separation unit and air separation cycle is disclosed that provides for up to about 96% recovery of argon, an overall nitrogen recovery of 98 percent or greater and limited gaseous oxygen production. The air separation is configured to produce a first high purity oxygen enriched stream and a second lower purity oxygen enriched stream from the lower pressure column, one of which is used as the refrigerant to condense the argon in the argon condenser, with the resulting vaporized oxygen stream used to regenerate the temperature swing adsorption pre-purifier unit. All or a portion of the first high purity oxygen enriched stream is vaporized in the main heat exchanger to produce the gaseous oxygen products.

Abstract: A moderate pressure air separation unit and air separation cycle is disclosed that provides for up to about 96% recovery of argon and an overall nitrogen recovery of 98% or greater. The air separation is configured to produce a high purity oxygen enriched stream which is used as the refrigerant to condense the argon in the argon condenser, with the resulting vaporized oxygen stream used to regenerate the temperature swing adsorption prepurifier unit. Argon recovery is facilitated with the use of an argon superstaged column.

Abstract: A moderate pressure air separation unit and air separation cycle is disclosed that provides for up to about 96% recovery of argon, an overall nitrogen recovery of 98 percent or greater and limited gaseous oxygen production. The air separation is configured to produce a first high purity oxygen enriched stream and a second lower purity oxygen enriched stream from the lower pressure column, one of which is used as the refrigerant to condense the argon in the argon condenser, with the resulting vaporized oxygen stream used to regenerate the temperature swing adsorption pre-purifier unit. All or a portion of the first high purity oxygen enriched stream is vaporized in the main heat exchanger to produce the gaseous oxygen products.

Abstract: In a process for delivering pressurized gas from an apparatus for separating air by cryogenic distillation, a stream of oxygen-rich liquid or gas having a nominal flow rate is withdrawn from a low-pressure column, an oxygen-rich liquid purge stream is withdrawn as bottoms from the low-pressure column and the oxygen-rich liquid purge stream is sent to a storage tank, in the event of a reduction in the production by the column system or an increase in the demand by a customer, a back-up stream is withdrawn from the storage tank and vaporized in a back-up reboiler and only if the liquid level in the storage tank exceeds a given threshold, a liquid stream is withdrawn from the storage tank constituting at most 2% of the nominal production output of the oxygen-rich stream and is sent to the back-up reboiler.

Abstract: A method and apparatus for producing an oxygen product in which air is separated in an installation including air separation units having higher and lower pressure columns. A pumped liquid stream generated within the installation, that can be a pumped liquid oxygen stream, is warmed within a main heat exchanger through indirect heat exchange with a compressed air stream to produce a liquid air stream. An impure oxygen stream is rectified within an auxiliary column to produce an oxygen containing stream that is introduced into the lower pressure column of each of the air separation units and intermediate liquid streams, composed of the liquid air stream or another air-like stream, reflux the lower pressure columns and the auxiliary column and optionally the higher pressure column of each of the air separation units.

Abstract: The process and the device are used for low-temperature separation of air with a distilling-column system for nitrogen-oxygen separation (20), which has at least one separation column (21, 22). A main air stream (1, 5) is compressed in an air compressor (2) and purified in a purification device (4). A first air stream (7) and a second air stream (8) are diverted from the main air stream (5). The first air stream (7) is further compressed in two secondary compressors (10, 13) that are connected in series. The further compressed first air stream (15) is cooled by indirect heat exchange (16), and at least partially liquefied or pseudo-liquefied, and then introduced into the distilling-column system for nitrogen-oxygen separation (20). The second air stream (8) is cooled by indirect heat exchange (16) and then, divided into two partial streams (24, 27), is actively depressurized in two expanders (25, 28), whereby the two expanders have essentially the same inlet pressure.

Abstract: Argon, oxygen and nitrogen contained within an incoming air feed is fractionated within an air separation system having a multiple column arrangement that includes a higher pressure column and a lower pressure column to produce oxygen and nitrogen-rich fractions and an argon column to produce an argon-rich fraction for recovery of the argon as an argon product. A two-phase stream can be formed by either expanding at least part of a liquid air stream or by a liquid oxygen column bottoms formed within a higher pressure column of the multiple column arrangement. The liquid air stream is formed by liquefying part of the air feed to be fractionated against vaporizing a pumped liquid stream composed of nitrogen and/or oxygen. The diversion of the nitrogen vapor contained in the nitrogen-rich fraction increases the liquid to vapor ratio within the lower pressure column to increase the argon recovery.

Abstract: An apparatus and process for producing pressurized gaseous product by air separation. A compressed air stream is cooled in an exchanger to form a compressed cooled air stream. The stream is then cryogenically compressed in a first compressor to form a first pressurized gas stream. The first pressurized gas stream is further cooled in the exchanger, cryogenically compressed in a second compressor, and then it is cooled and partially liquefied. The cooled and partially liquefied product is then fed to a system of distillation columns. A liquid product is removed from the system of distillation columns. This product is then pressurized, vaporized and warmed in the exchanger to yield pressurized gaseous product.

Abstract: A method for separating air by cryogenic distillation. A first compressor compresses air to a first pressure, and sends part of that air to a second compressor which compresses that part to a second pressure. Part of the air at the second pressure is cooled in a heat exchanger and sent to a third compressor where part of it is compressed to a third pressure. Part of the air at the third pressure is liquefied and sent a column system. Around half of the total liquefied air sent to the column system will have originally been compressed by the third compressor. Part of the air at the first pressure is cooled in a heat exchanger and part of the cooled air at the first pressure is then expanded to the pressure of the column system. The expanded air is sent to the column system.

Abstract: A three column cryogenic rectification system for producing at least one of oxygen and nitrogen employing a medium pressure column which is operating at a pressure between the operating pressures of the higher and lower pressure columns, and which receives an air feed which is at a lower pressure than the air feed to the higher pressure column. The medium pressure column processes oxygen-enriched liquid from the higher pressure column and is reboiled by a fluid taken from below the top of the higher pressure column.

Abstract: A system for purifying and reclaiming argon from an industrial process wherein oxygen is removed by hydrogenation and dehydration, and nitrogen and hydrogen are removed by cryogenic separation.

Abstract: In an apparatus for the separation of air by cryogenic distillation, the overhead gas of a mixing column is sent to the passages for warming a bottom reboiler of the low-pressure column of a double column fed with air to be distilled. The production of oxygen in the bottom of the low-pressure column is increased.

Abstract: A process for enhancing recovery of ethylene, ethane and heavier components using a cryogenic distillation column which involves dividing the feed gas into a first gaseous stream and a main gaseous stream. The first gaseous stream is compressed and cooled, and then expanded and introduced into the cryogenic distillation column as main reflux stream, or is further processed to generate at least one reflux stream to the cryogenic distillation column.

Abstract: A double column air separation method in which a first stream of compressed air is cooled by passage through a main heat exchanger from its warm end countercurrently to a nitrogen stream withdrawn from the top of a lower pressure rectification column. The first stream of compressed air flows from the main heat exchanger into a higher pressure rectification column through an inlet. A second stream of compressed air is also passed into the warm end of the main heat exchanger and is cooled therein. The second stream of compressed air passes out of heat exchange with the nitrogen stream at a temperature lower than the exit temperature therefrom of the first stream of compressed air and at least 5K lower than the bubble point temperature of air at the pressure prevailing at the inlet. A stream of oxygen-enriched liquid passes isenthalpically from the bottom of the higher pressure column to the lower pressure column.

Abstract: A cryogenic air separation system, which may be used to produce ultra high purity nitrogen or ultra high purity oxygen, wherein kettle liquid is vaporized in two steps using a split kettle top condenser and vapor from the first step compressed and then recycled to the cryogenic rectification column.

Abstract: In an apparatus for the separation of air by cryogenic distillation, the overhead gas of a mixing column is sent to the passages for warming a bottom reboiler of the low-pressure column of a double column fed with air to be distilled.

Abstract: A cryogenic air separation system wherein product oxygen may be produced effectively at a higher production rate and at a lower production rate than the nominal production rate by employing a liquid oxygen storage tank and, in addition, an oxygen-enriched liquid storage tank operating in conjunction with the higher pressure column sump.

Abstract: Air is separated in a double rectification column comprising a higher pressure rectification column, a lower pressure rectification column, and a first condenser-reboiler, of which the condensing passages communicate with an upper region of the higher pressure rectification column, and the reboiling passage communicate with a lower region of the lower pressure rectification column. A second condenser-reboiler is operated so as to reboil a liquid fraction obtained in the higher pressure rectification column. A stream of the air to be separated is partially or totally condensed by indirect heat exchange with a stream of nitrogen condensed in the first condenser-reboiler. At least part of the stream of condensed nitrogen is taken as product downstream of its heat exchange with the second stream of compressed air.

Abstract: In order to allow more flexible operation of a column for separating air by cryogenic distillation, a first air stream (6) exchanges heat with a liquid (16) which vaporizes, while a second air stream (7, 7A) is drawn off from an intermediate level in the exchange line and sent to a column in order to be distilled therein.

Abstract: A cryogenic rectification method wherein both nitrogen gas and liquid are efficiently produced from air employing one or two columns wherein refrigeration to drive the cryogenic separation is provided by a, preferably closed loop, multicomponent refrigerant fluid refrigeration circuit.

Abstract: A process and associated apparatus for removing aromatics and/or higher molecular weight hydrocarbons from a methane-based gas stream comprising the steps of (a) condensing a minor portion of the methane-based gas stream thereby producing a two-phase stream, (b) feeding said two phase stream to the upper section of a column, (c) removing from the upper section of the column an aromatic- and/or heavies-depleted gas stream, (d) removing from the lower section of the column an aromatic- and/or heavies-rich liquid stream, (e) contacting via indirect heat exchange the aromatic- and/or heavies-rich liquid stream with a methane-rich stripping gas thereby producing a warmed liquid stream and a cooled stripping gas stream, (f) feeding said cooled stripping gas stream to the lower section of the column; and (g) contacting said two-phase stream and the cooled stripping gas stream in the column thereby producing the aromatic- and/or heavies-depleted gas stream and the aromatic- and/or heavies-rich liquid stream.

Abstract: A plant which, when used to produce pressurized oxygen gas, includes a switch, e.g. a liquid oxygen/liquid air switch, for meeting relatively long-term peak demand as well as short-term, high-amplitude peak demand, and a circuit (13,30) for compressing oxygen to a pressure higher than the production pressure. This circuit leads to a buffer (15) at least partially meeting short-term, high-amplitude peak demand.

Abstract: Air is separated into oxygen and nitrogen in a double rectification column comprising a higher pressure rectification column and a lower pressure rectification column. Liquid nitrogen reflux for the separation is provided by condensing nitrogen vapor taken from the column in a condenser-reboiler. Additional separation is performed in an intermediate pressure rectification column. A first stream of argon-enriched vapor is withdrawn from an intermediate region of the lower pressure rectification column and has an argon fraction separated from it in a first side rectification column. A second stream of argon-enriched vapor is similarly withdrawn and is separated in a second side rectification column which provides vapor to heat a reboiler associated with the intermediate pressure rectification column. Alternatively a stream of oxygen vapor can be so employed instead of the second argon-enriched vapor stream.

Abstract: A single column cryogenic rectification system for producing lower purity oxygen wherein a major portion of the feed air is partially condensed in the column reboiler, the resulting vapor turboexpanded and then successively condensed in one or more vertically oriented stages within the column to enhance the generation of upflow vapor and reflux liquid for the column.

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: A method and apparatus for making gaseous oxygen at a delivery pressure in a single column oxygen generator. In accordance with the method and apparatus, a column bottoms stream composed of the product is pumped to the delivery pressure and then vaporized. A liquid coolant stream used in condensing reflux is recompressed by a recycle compressor and then recycled back into the bottom of the column. Such recycled stream has a higher nitrogen content than the column bottoms. Part of the nitrogen tower overhead, not used in forming the reflux, is turbo-expanded by a turbo-expander coupled to the recycle compressor.

Abstract: A fluid mixture is separated by distillation in a two column system in which a portion of the feed is prefractionated in a first column having at least one separation stage above the feed and the prefractionator bottoms provides feed to a second column operating at a lower pressure. Cooling for condensing the overhead vapor of the first column is provided by heat exchange with flashed prefractionator bottoms or with an intermediate fluid in the second column. Another portion of the feed is flashed and introduced into the second column. The two-column system is readily combined with a high pressure column in a three-column distillation system for separating air which is particularly useful for integration with a gasification combined cycle combustion turbine system. Optionally, three nitrogen products can be produced at three different pressures.

Abstract: For the method, air (103, 104) is fractionated in a medium-pressure column (6) and a low-pressure column (5). The sump heating (3) of the low-pressure column (5) is carried out with a second airflow (204), which is liquefied at the same time. An intermediate fraction (18) is taken from the low-pressure column (5) and evaporated in the head condenser (10) of the medium-pressure column (6). The thereby resulting vapor (19) is returned to the low-pressure column. In the event that impure oxygen is obtained, the second airflow (203, 204) is recompressed (202) upstream from the sump heating (3), external energy being supplied, to a pressure above that of the medium-pressure column, the pressure being relieved downstream from the sump heating (3) in a first pressure relief valve (208) to the pressure of the medium-pressure column (6).

Abstract: A cryogenic rectification system for producing low purity oxygen and high purity nitrogen, preferably at elevated pressure, wherein nitrogen-rich vapor from a higher pressure column is turboexpanded and condensed against lower pressure column intermediate liquid prior to being passed into the lower pressure column and low purity oxygen is produced in an auxiliary side column driven by fluid from the higher pressure column.

Abstract: The process and the device are used for low-temperature separation of air. A first split stream of compressed and purified air is cooled, fed to a main rectifying system and separated there into liquid oxygen and gaseous nitrogen. A liquid product fraction (for example, oxygen and/or nitrogen) is vaporized in indirect heat exchange with a second split stream of compressed and purified air. The second split stream condenses during indirect heat exchange at least partially. At least a portion of the second split stream, downstream from indirect heat exchange with the liquid product fraction, is used as cooling medium for top cooling of a crude argon column downstream from the main rectifying system. The second split stream makes available all or essentially all the cold needed for liquefaction of crude argon.

Abstract: A process for producing an ultra-high purity fluid product comprising the steps of collecting in the lower portion of a cryogenic fractionation zone an ultra-high purity fluid product; providing reboil to said fractionation zone by condensing a portion of a lesser purity composition of the same fluid product by indirect heat exchange in a first reboiler; and vaporizing said portion of said lesser purity composition by indirect heat exchange with a warmer stream of an impure fluid.