An apparatus for separation of air by cryogenic distillation comprising: a system of columns; a first turbine; a warm compressor coupled to the first turbine; a second turbine; a cold compressor coupled to the second turbine; a heat exchanger; means for sending air cooled in the heat exchanger at an intermediate temperature of the heat exchanger to the cold compressor; means for sending expanded air from the second turbine to the system of columns; means for sending air compressed in the cold compressor to an intermediate point of the heat exchanger and then at least in part to the system of columns via a first valve; means for sending air compressed in the cold compressor to the inlet of the first turbine via a second valve without passing through the heat exchanger, wherein the means for sending air compressed in the cold compressor to the inlet of the first turbine via the second valve without passing through the heat exchanger is also connected to the inlet of the first turbine; means for sending a fraction of air cooled in the heat exchanger to an intermediate temperature of the latter to the first turbine; means for sending expanded air from the first turbine to the system of columns; and a bypass line provided with an expansion valve configured to send air from the cold compressor to the system of columns without passing through the heat exchanger.

A gas turbine plant includes a gas turbine, a liquefaction facility capable of liquefying air, and a liquefaction controller. A compressor has an intake amount adjuster capable of adjusting an intake amount into a compressor casing. The liquefaction facility includes: a bleed line capable of bleeding compressed air from the compressor; a liquefaction system capable of liquefying the compressed air, a bleed amount adjustment valve; a return air line capable of guiding return air into a flow passage through which compressed air flows in the gas turbine; and a return amount adjusting valve. The liquefaction controller opens the bleed amount adjustment valve if an opening degree of the intake amount adjuster is a first opening degree, and opens the return amount adjusting valve if the opening degree of the intake amount adjuster is a second opening degree, which is an opening degree greater than the first opening degree.

A method for producing an air product in an air separation plant. Feed air is cooled at least in a main air compressor and is fed into a distillation column system. A fluid storage unit and a cold accumulator are used. In a first operating mode, fluid is stored in the fluid storage unit and the cold accumulator is heated. In a third operating mode, fluid is released and the cold accumulator is cooled, and in a second operating mode, fluid is neither stored nor released.

A centrifugal compressor, the capacity of which can be increased with keeping the diameter of the impeller at minimum, is provided. The centrifugal compressor includes: a drive gear (11); a drive shaft (3) protruding from one side of the drive gear (11) in a central axis direction of the drive gear (11); a no. 1 driven pinion gear (12) configured for rotation of the drive gear (11) to be transmitted thereto; a no. 1 driven pinion shaft (5) protruding from both sides of the no. 1 driven pinion gear (12) in a central axis direction of the no. 1 driven pinion gear (12); and a couple of first stage compressor sections (7a, 7b), each of which is provided in each end of the no. 1 driven pinion shaft (5) and is configured to compress fluid by rotation of the no. 1 driven pinion shaft (5).

A method for obtaining an air product from an air separation plant having a distillation column system and a tank system. The tank system includes a first tank and a second tank. Cryogenic liquid is withdrawn from the distillation column system, stored in the tank system, and used as the air product. The cryogenic liquid is supplied to the first tank and withdrawn from the second tank during a first period, and is supplied to the second tank and withdrawn from the first tank during a second period. The tank system has a third tank to which cryogenic liquid withdrawn from the first tank and the second tank is transferred unheated. The air product is withdrawn from the third tank in liquid state, vaporized and discharged. Alternatively, the cryogenic liquid can be withdrawn from the third tank and stored in the liquid state in a fourth tank.

A liquid air energy storage system comprises an air liquefier, a liquid air storage facility for storing the liquefied air, and a power recovery unit coupled to the liquid air storage facility. The air liquefier comprises an air input, an adsorption air purification unit for purifying the input air, and a cold box for liquefying the purified air. The power recovery unit comprise a pump for pressurizing the liquefied air from the liquid air storage facility; an evaporator for transforming the high-pressure liquefied air into high-pressure gaseous air; an expansion turbine capable of being driven by the high-pressure gaseous air; a generator for generating electricity from the expansion turbine; and an exhaust for exhausting low-pressure gaseous air from the expansion turbine. The exhaust is coupled to the adsorption air purification unit such that at least a portion of the low-pressure gaseous air exhausted from the expansion turbine is usable to regenerate the adsorption air purification unit.

A method for separating air by cryogenic distillation wherein, during a first run, a first flow rate of air is compressed in at least one compressor, cooled and separated in a system of columns, a first flow rate of a first distillation product is produced, voltage electricity requirements of the compressor or compressors of the method are met from an electricity grid, during a second run, a second flow rate of air lower than the first flow rate of air is compressed in the compressor, the second flow rate is cooled and separated in the system of columns, a second flow rate of a first distillation product is produced, lower than the first flow rate of the first product, voltage electricity requirements of the compressor being lower than during the first run and, during an intermediate run taking place after the first run and before the second run.

A system and method for separating air in an air separation plant is provided. The disclosed systems and methods divert a portion of the compressed, purified air stream to a bypass system configured to selectively produce a higher pressure compressed output stream or a lower pressure compressed output stream. The higher pressure and/or lower pressure compressed output streams are cooled in a main heat exchanger by indirect heat transfer with a plurality of product streams from the air separation plant and then rectified in the distillation column system. A second portion of the compressed, purified air stream is partially cooled in the main heat exchanger and expanding in a turbo-expander to produce power and an exhaust stream which is directed to the distillation column system of the air separation plant where it imparts additional refrigeration generated by the expansion of the compressed air stream in the turbo-expander.

A distillation column system and a plant are for production of oxygen by cryogenic fractionation of air. The distillation column system has a high-pressure column and a low-pressure column, a main condenser, and an argon column with an argon column top condenser. The low-pressure column comprises an upper mass transfer region, a lower mass transfer region and a middle mass transfer region. The argon column top condenser is arranged within the low-pressure column between the upper and middle mass transfer regions and is configured as a forced-flow evaporator.

A system and method for separating air in an air separation plant is provided. The disclosed systems and methods divert a portion of the compressed, purified air stream to a bypass system configured to selectively produce a higher pressure compressed output stream or a lower pressure compressed output stream. The higher pressure and/or lower pressure compressed output streams are cooled in a main heat exchanger by indirect heat transfer with a plurality of product streams from the air separation plant and then rectified in the distillation column system. A second portion of the compressed, purified air stream is partially cooled in the main heat exchanger and expanding in a turbo-expander to produce power and an exhaust stream which is directed to the distillation column system of the air separation plant where it imparts additional refrigeration generated by the expansion of the compressed air stream in the turbo-expander.