A method and device used to variably obtain a compressed-gas product by means low-temperature separation of air in a distillation column system. In a first operating mode, a first amount of first compressed-gas product is obtained, and, in a second operating mode, a second, smaller amount is obtained. In the first operating mode, a first amount of air is compressed in the main air compressor, and in the second operating mode, a second, larger amount is compressed in the main air compressor.

The present invention relates to a method for utilising a target gas flow consisting of pressurised target gas, which is provided by a continuously-operated gas decomposition device, wherein the target gas flow is supplied to a target load which discontinuously decreases the target gas flow, so that occasionally an excess target gas flow that is not decreased by the target load accrues, as well as a system for supplying a target load. The excess target gases occurring in a gas decomposition device and optionally additionally resulting waste gases may be used in a resource-saving manner through the method and the system according to the invention. This is achieved by the excess target gas flow being supplied as a propellant gas to a compressor which compresses another gas and supplies it as a compressed gas in a compressed gas line, via which it is fed to another load.

A method and a device used to variably obtain a compressed-gas product by means of the low-temperature separation of air in a distillation column system. In a first operating mode, a first amount of first compressed-gas product is obtained, and, in a second operating mode, a second, smaller amount is obtained. In the first operating mode, a first amount of high-pressure column nitrogen is compressed in a nitrogen compressor and in the second operating mode, a second, larger amount is compressed in the nitrogen compressor.

A method and apparatus to obtain a compressed nitrogen product by low-temperature fractionation of air in a distillation column system. The system has a high-pressure column, a low-pressure column, a main condenser, and a low-pressure column top condenser. Bottoms liquid from the low-pressure column is evaporated in the top condenser and the gas formed is decompressed to perform work that drives a cold compressor. A gaseous first compressed nitrogen product stream from the high-pressure column is warmed in the main heat exchanger. A further gaseous nitrogen stream from the low-pressure column is compressed in the cold compressor and warmed as a second compressed nitrogen product stream in the main heat exchanger. The cold compressor overcomes a pressure differential which is at least equal to two thirds of the pressure differential between the top of the high-pressure column and the top of the low-pressure column.

A method and apparatus for producing compressed nitrogen and liquid nitrogen. A separation system has a high-pressure column, a low-pressure column with a top condenser and a main condenser. Air is compressed in an air compressor, purified, cooled in a heat exchanger and introduced into the high-pressure column. A first part of the gaseous top nitrogen from the low-pressure column becomes compressed nitrogen product. A second part of the gaseous top nitrogen is condensed in the condensing space of the top condenser and vapour is drawn off as a residual gas stream. The vapor is expanded in a first expansion machine. A second compressed nitrogen stream from the top of the high-pressure column is expanded in a second expansion machine and then drawn off as compressed nitrogen product. A part of the nitrogen condensed in the top condenser is drawn off as liquid nitrogen product.

The method for the production of nitrogen can include the steps of a) providing a waste nitrogen gas stream at a first pressure called low pressure, wherein the waste nitrogen gas originates from a low pressure column of a cryogenic air separation unit; b)compressing the waste nitrogen gas stream to a second pressure in a waste nitrogen compressor to produce a pressurized nitrogen stream; and c) introducing the pressurized nitrogen stream to a nitrogen generator under conditions effective for producing a purified nitrogen product, wherein the purified nitrogen product has a higher concentration of nitrogen as compared to the pressurized nitrogen stream.

A method and a device used to variably obtain a compressed-gas product by means of the low-temperature separation of air in a distillation column system. In a first operating mode, a first amount of first compressed-gas product is obtained, and, in a second operating mode, a second, smaller amount is obtained. In the first operating mode, a first amount of high-pressure column nitrogen is compressed in a nitrogen compressor and in the second operating mode, a second, larger amount is compressed in the nitrogen compressor.

A method and device used to variably obtain a compressed-gas product by means low-temperature separation of air in a distillation column system. In a first operating mode, a first amount of first compressed-gas product is obtained, and, in a second operating mode, a second, smaller amount is obtained. In the first operating mode, a first amount of air is compressed in the main air compressor, and in the second operating mode, a second, larger amount is compressed in the main air compressor.

In a method for supplying nitrogen to a combustion chamber, gaseous nitrogen (9) is drawn off from an air separation unit (7) at a first pressure, the nitrogen is compressed in at least two stages (C1, C2) of a nitrogen compressor and sent to a combustion chamber (25) at a second pressure, which is the output pressure of the last stage (C3) of the nitrogen compressor, between two stages of the nitrogen compressor the nitrogen is humidified by direct contact in passing through a contactor (17) supplied at its top with water, and the humidified nitrogen is compressed in at least one stage of the nitrogen compressor and sent to the combustion chamber.

A process for cryogenic fractionation of air uses an air fractionation plant (100-400) comprises a rectification column system (10) having a high-pressure column (11) operated at a pressure level of 9 to 14.5 bar, a low-pressure column (12) operated at a pressure level of 2 to 5 bar, and an argon column (13). A recirculating stream is formed using a second top gas or a portion thereof, which is heated, compressed, cooled again, and after partial or complete liquefaction or in the unliquefied state is introduced partially or completely, or in fractions, into the first rectification column (11) and/or into the second rectification column (12).