A method of efficient cold recovery from a liquid hydrogen stream includes warming a cold liquid hydrogen stream by indirect heat exchange with a cold feed air stream in an ASU sub-cooler, thereby producing a warmed liquid hydrogen stream. Wherein at least a portion of the cool inlet air stream is introduced into a cold booster, thereby producing the compressed cool feed air stream. Wherein at least a first portion of the further cooled feed air stream is introduced into an expander, thereby producing an expanded feed air stream. Wherein a second portion of the further cooled feed air stream is further cooled, thereby producing the cold feed air stream. And, wherein the liquid oxygen stream has a first molar mass flow rate, and the cold liquid hydrogen stream has a second molar flow rate that is between 1.5 and 2.5 times the first molar mass flow rate.

A process for recovering at least one fluid (e.g. argon gas and/or nitrogen gas, etc.) from a feed gas (e.g. air) can provide an improved recovery of argon and/or nitrogen as well as an improvement in operational efficiency. Some embodiments can be adapted so that at least a portion of a mixed nitrogen-oxygen fluid is at least partially vaporized and fed to a low pressure column.

A method for the low-temperature separation of air using an air separation plant which comprises a rectification column arrangement (10) having a pressure column, a low-pressure column and an argon column, wherein: the low-pressure column comprises a first and a second rectification region (A, B); the argon column comprises a first and a second rectification region (C, D, D1, D2); argon-enriched fluid is removed from the low-pressure column between the first and second rectification region (A, B) thereof and is fed into the first rectification region (C) of the argon column; and argon-depleted fluid is removed from the first rectification region (C) of the argon column (13a, 13b) and is fed into the low-pressure column between the first and second rectification region (A, B) thereof.

The invention relates to a plant for low-temperature air separation, having a rectification column system comprising a high-pressure column, a divided low-pressure column and a divided argon column, and a cold box system comprising a first cold box and a second cold box. The high-pressure column is arranged beneath the lower section of the low-pressure column. The high-pressure column together with the lower section of the low-pressure column is located in the first cold box, and the top section of the low-pressure column in the second cold box. It is proposed to arrange the base section of the argon column in the first cold box and the top section of the argon column in the second cold box, or vice versa. The present invention likewise provides a corresponding method.

The invention relates to a plant for low-temperature fractionation of air, having a rectification column system comprising a high-pressure column, a divided low-pressure column and an argon column, and a coldbox system comprising a first coldbox, a second coldbox and a third coldbox. The high-pressure column is disposed beneath the lower section of the low-pressure column. The high-pressure column together with the lower portion of the low-pressure column is disposed in the first coldbox, and the top portion of the low-pressure column in the second coldbox. It is proposed that the argon column or one or more sections of the argon column be disposed in the third coldbox. The pure oxygen column is disposed in the second coldbox. The present invention likewise provides a corresponding process.

A process for recovering at least one fluid (e.g. argon gas and/or nitrogen gas, etc.) from a feed gas (e.g. air) can provide an improved recovery of argon and/or nitrogen as well as an improvement in operational efficiency. Some embodiments can be adapted so that at least a portion of a mixed nitrogen-oxygen fluid is at least partially vaporized and fed to a low pressure column.