Abstract: Process and installation for the production of gaseous oxygen and/or gaseous nitrogen under pressure, of the type in which air is distilled in a double distillation column (11) comprising a low pressure column (13) operating under a so-called low pressure, and a medium pressure column (12) operating under a so-called medium pressure. All the air to be distilled is compressed (in 1, 3, 7)to at least one high air pressure substantially greater than the medium pressure, and the compressed air is cooled to an intermediate temperature, and a portion of it is expanded in a turbine (8) to the medium pressure, before introducing it into the medium pressure column (12). The air which has not been expanded is liquefied, then introduced after expansion (in 20, 21), into the double column. At least one liquid product withdrawn from the double column is brought to the production pressure, and this liquid product is vaporized by heat exchange with at least one portion of the air to be distilled in the course of cooling.

Abstract: Process for the operation of a gas turbine group (1) producing energy by combustion of a gaseous fuel (24) with a mixture of air gas. There is interconnected with the group (1) an air gas separation unit (7) producing at least two air gases (9; 10-13). The operating conditions of the turbine (3) of the group are maintained similar to those of maximum power production by selecting, with the aid of the separation unit (7), the parameters of the mixture of air gas.

Abstract: In this process of the liquid nitrogen/rich liquid HPN swing type, the connection between the head of the column (4) and the liquid nitrogen holding tank (7) is effected, for the two flow directions of the liquid nitrogen, by a single conduit (12) equipped with a pressure reducing device (13). The direction and the flow rate of the liquid nitrogen flow are controlled by the variations of the pressure of the column, and the holding tanks of liquid nitrogen and rich liquid are maintained at constant pressures.

Abstract: Process and installation for transferring a liquid, via a rising conduit (6, 9, 11, 12) provided with an expansion valve (7, 10, 13), from a first distillation column (2), operating at a first pressure, to equipment (3), particularly a second distillation column, operating at a pressure lower than the first pressure. There is injected into the rising conduit, downstream of the expansion valve, a lift gas available at a pressure greater than the pressure created by a column of liquid between the point of injection of the gas and the point of introduction of the liquid into the equipment (3). The lift gas is available at the pressure of the first distillation column (2) and is injected into the liquid in the rising column above the point of withdrawal of this liquid. There is used as lift gas a gas withdrawn from a point in the first column (2) and so chosen as not to modify substantially the composition of the transferred liquid, or a portion of the air feed to the installation can be used for this purpose.

Abstract: This process is of the alternating type. When the demand of oxygen is lower than the mean value, additional liquid oxygen is produced by introducing compressed oxygen, in gaseous form, in the heat exchange line of the arrangement, the flow of liquid nitrogen injected into the double column being reduced in a corresponding manner. It is thus possible to increase the average yield of the arrangement when extracting argon.

Abstract: To meet the requirement of a variable demand of gaseous oxygen, a constant flow of liquid oxygen is sent from the double distillation column into a container, and a variable flow of liquid oxygen is withdrawn therefrom, which is thereafter vaporized in a heat exchanger by condensation of a corresponding flow of incoming air. The liquefied air is stored in a second container, from which a constant flow of liquefied air is sent into the double column.

Abstract: The present invention relates to methods and a system for cooling a gas for the purpose of effecting the liquefaction of one or more components of this gas. The invention is more precisely concerned with the prevention of losses by evaporation from the tanks of methane-carrier ships during the transport of liquid methane. For this purpose, the evaporation leakages from the tanks in gaseous form are re-liquefied by ad hoc liquefaction apparatus aboard the ship. The apparatus utilizes a cascade frigorific cycle of the open type working with a single refrigerant having a plurality of components. The refrigerant comprises the pure substance to be re-liquefied, and at least one heavy component, less volatile than the said substance, and absent from the composition of the gas treated.