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.

An air separation process having a first booster air compressor comprising a first outlet stream and a second booster air compressor comprising a second outlet stream. Wherein the first booster air compressor and the second booster air compressor are in parallel, and the second booster air compressor is driven by a nitrogen turboexpander. The first outlet stream and/or the second outlet stream may be at least partially condensed by heat exchange with a vaporizing low pressure oxygen stream, and the low-pressure gaseous oxygen pressure is in the range of 1.1 bara to 3 bara.

A method and device to produce oxygen by the low-temperature separation of air at variable energy consumption. A distillation column system comprises a high-pressure column, a low-pressure column and a main condenser, a secondary condenser and a supplementary condenser. Gaseous nitrogen from the high-pressure column is liquefied in the main condenser in indirect heat exchange with an intermediate liquid from the low-pressure column. A first liquid oxygen stream from the bottom of the low-pressure column is evaporated in the secondary condenser in indirect heat exchange with feed air to obtain a gaseous oxygen product. The supplementary condenser serves as a bottom heating device for the low-pressure column and is heated by means of a first nitrogen stream from the distillation column system, which nitrogen stream was compressed previously in a cold compressor.

A method for operating an air separation unit during an unexpected disturbance is provided. The method can include the steps of: determining that a process disturbance has occurred; starting-up a liquid back-up system that is configured to deliver a product gas at a desired product pressure; and introducing compressed air from an air accumulator into the air separation unit at a location that is downstream a main air compressor and upstream a cold box, wherein the compressed air is introduced in an amount that is effective for maintaining nominal operation of the air separation unit during the process disturbance and until the liquid back-up system is delivering the product gas at the desired product pressure.

A gas production system that can supply liquefied gas obtained by rectifying source gas as product gas continuously with high heat efficiency without using a machine that has a risk of contamination like a pump. A gas production system includes a single pressure device having a single pressurized container to which liquefied gas extracted from a rectification unit is supplied, a pressure line for extracting and vaporizing a part of the liquefied gas in the pressurized container and returning the part of the liquefied gas to the pressurized container, and a second heat exchange unit that is disposed in the pressure line, and a liquefied gas storage unit that stores liquefied gas which is led out from the pressurized container.

Process for vaporizing purge liquid from a cryogenic liquid vaporizer, the liquid containing at least one impurity, in which the purge liquid is withdrawn from a bath of liquid surrounding the vaporizer or resulting from the vaporizer, all of the purge liquid is vaporized in a heater, characterized in that the content of the at least one impurity in at least one portion, or even all of the heated vaporized liquid is analysed and the flow rate of at least one portion, or even all of the heated vaporized liquid is measured.

A method for obtaining one or more air products, wherein an air separation system having a rectification column system is used, in which pressurized air is processed in an adjustable total air volume, wherein the total air volume is set to a first value during a first operating period and set to a second value that is different from the first value during a second operating period, and wherein the setting of the total air volume is changed from the first value to the second value in a third operating period from a first time to a second time. The second operating period is after the first operating period, the third operating period is between the first operating period and the second operating period. In the third operating period, a setting of a volume of a fluid, is changed from a third time up to a fourth time.

A method for converting excess liquid oxygen into liquid nitrogen, including introducing a gaseous nitrogen stream into a main heat exchanger, therein exchanging heat with a vaporized oxygen stream, a vapor phase nitrogen steam, and a waste liquid nitrogen stream; thereby producing a cold gaseous nitrogen stream, an oxygen vent stream, a nitrogen vent steam, and a gaseous nitrogen waste stream, introducing the cold gaseous nitrogen stream into a secondary heat exchanger, therein exchanging heat with a liquid oxygen stream; thereby producing the vaporized oxygen stream and a cold liquid nitrogen stream, introducing the cold liquid nitrogen stream into a nitrogen pressure reduction valve thereby producing a two-phase nitrogen stream, introducing the two-phase nitrogen stream into a nitrogen flash vessel thereby producing a liquid phase nitrogen stream and the vapor phase nitrogen stream, wherein the method is performed in the absence of refrigerant turbo-expanders, refrigerant expansion turbines, or refrigerant compressors.

An apparatus for converting excess liquid oxygen into liquid nitrogen, including a main heat exchanger to exchange heat between a gaseous nitrogen stream, a vaporized oxygen stream, a vapor phase nitrogen steam, and a waste liquid nitrogen stream; thereby producing a cold gaseous nitrogen stream, an oxygen vent stream, a nitrogen vent steam, and a gaseous nitrogen waste stream, a secondary heat exchanger to exchange heat between a liquid oxygen stream and the cold gaseous nitrogen stream; thereby producing the vaporized oxygen stream and a cold liquid nitrogen stream, a nitrogen pressure reduction valve to reduce the pressure of the cold liquid nitrogen stream; thereby producing a two-phase nitrogen stream, a nitrogen flash vessel to receive the two-phase nitrogen stream, and to generate a liquid phase nitrogen stream and a vapor phase nitrogen stream, wherein the apparatus does not include any refrigerant turbo-expanders, refrigerant expansion turbines, or refrigerant compressors.

An apparatus for separating air, comprising a double column, means for sending air to the purification unit at a pressure that is no more than 1 bar higher than atmospheric pressure, a pipe for sending a first air flow, the first air flow having been purified in the purification unit, to the heat exchanger at a fourth pressure that is no more than 1 bar higher than the second pressure, a pipe for sending the first purified air flow, which has been cooled in the heat exchanger, to the second column for separation, and a booster compressor, the apparatus not comprising any means for depressurizing the first flow.