A method and the apparatus for the cryogenic separation of air in an air separation plant which has a main air compressor, a main heat exchanger and a distillation column system with a high-pressure column and a low-pressure column. All of the feed air is compressed in the main air compressor to a first air pressure which is at least 3 bar higher than the operating pressure of the high-pressure column. A first part of the compressed total air flow, as first air flow at the first air pressure, is cooled and liquefied or pseudo-liquefied in the main heat exchanger, then expanded and introduced into the distillation column system. A second part of the compressed total air flow, as second air flow, is post-compressed in an air post-compressor to a second air pressure and at least part is further compressed in a first turbine-driven post-compressor to a third air pressure.

A nitrogen liquefier configured to be integrated with an argon and nitrogen producing cryogenic air separation unit and method of nitrogen liquefaction are provided. The integrated nitrogen liquefier and associated methods may be operated in at least three distinct modes including: (i) a nil liquid nitrogen mode; (ii) a low liquid nitrogen mode; and (iii) a high liquid nitrogen mode. The present systems and methods are further characterized in an oxygen enriched stream from the lower pressure column of the air separation unit is an oxygen enriched condensing medium used in the argon condenser.

A method and apparatus serve for the cryogenic separation of air in an air separation plant which has a main air compressor, a main heat exchanger and a distillation column system with a high-pressure column and a low-pressure column. All of the feed air is compressed in the main air compressor to a first air pressure which is at least 3 bar higher than the operating pressure of the high-pressure column. A first part of the compressed total air flow, as first air flow at the first air pressure, is cooled and liquefied or pseudo-liquefied in the main heat exchanger, then expanded and introduced into the distillation column system. A second part of the compressed total air flow, as second air flow, is post-compressed in a turbine-driven post-compressor to a second air pressure.

A method including, compressing a first hydrogen stream, and expanding a portion to produce a hydrogen refrigeration stream, cooling a second hydrogen stream thereby producing a cool hydrogen stream, wherein at least a portion of the refrigeration is provided by a nitrogen refrigeration stream, further cooling at least a portion of the cool hydrogen stream thereby producing a cold hydrogen stream, and a warm hydrogen refrigeration stream wherein at least a portion of the refrigeration is provided by the hydrogen refrigeration stream, compressing the warm hydrogen refrigeration stream, mixing the balance of the compressed first hydrogen stream with a high-pressure gaseous nitrogen stream to form an ammonia synthesis gas stream, and wherein the first hydrogen stream and the warm hydrogen refrigeration stream are compressed in the same compressor.

A method for obtaining one or more air products, in which method an air fractionation plant is used which has a column system with a pressure column, wherein air is fedto the column system and is fractionated in the column system, wherein at least 90% of the total amount of air supplied to the column system is compressed, wherein nitrogen-rich gas is extracted from the pressure column, and wherein, at least in a first operating mode, further air is compressed to a pressure level above the base pressure level, is expanded, and is warmed without fractionation in the column system. It is provided that, at least in the first operating mode, a proportion of the nitrogen-rich gas extracted from the pressure column is fed to the further air upstream of the expansion.

A hydrogen feed stream is introduced into a primary refrigeration system of a precooling system and cooling the hydrogen stream to a first precooling temperature. From there, the precooled hydrogen stream is then introduced to a secondary refrigeration system of the precooling system and cooling the precooled hydrogen stream to a second temperature. Next, the cooled hydrogen stream is then liquefied in the liquefaction system to produce liquid hydrogen.

An integrated industrial unit is provided, which can include: a nitrogen source configured to provide liquid nitrogen; a hydrogen source; a hydrogen liquefaction unit, wherein the hydrogen liquefaction unit comprises a precooling system, and a liquefaction system; and a liquid hydrogen storage tank, wherein the precooling system is configured to receive the gaseous hydrogen from the hydrogen source and cool the gaseous hydrogen to a temperature between 75 K and 100 K, wherein the precooling system comprises a primary refrigeration system and a secondary refrigeration system, wherein the liquefaction system is in fluid communication with the precooling system and is configured to liquefy the gaseous hydrogen received from the precooling system to produce liquid hydrogen, wherein the liquid hydrogen storage tank is in fluid communication with the liquefaction system and is configured to store the liquid hydrogen received from the liquefaction system.

A hydrogen feed stream is introduced into a primary refrigeration system of a precooling system and cooling the hydrogen stream to a first precooling temperature. From there, the precooled hydrogen stream is then introduced to a secondary refrigeration system of the precooling system and cooling the precooled hydrogen stream to a second temperature. Next, the cooled hydrogen stream is then liquefied in the liquefaction system to produce liquid hydrogen. The refrigeration is provided by expansion of a pressurized gaseous nitrogen stream and vaporization of a liquid nitrogen stream that is sourced from a nearby air separation unit.

An apparatus for the separation of air by cryogenic distillation comprises a column system, a heat exchanger, a turbine, means for sending compressed and purified air at a first pressure to be cooled at the first pressure in the heat exchanger, means for sending a first gaseous stream having a nitrogen content at least that of air to be cooled and liquefied or pseudo liquefied in the heat exchanger to form a liquefied stream, means for sending at least part of the liquefied stream to be warmed and vaporized in the heat exchanger to a first intermediate temperature of the heat exchanger to form a vaporized stream, means for removing the vaporized stream from an intermediate section of the heat exchanger, a conduit for sending the vaporized stream to be expanded, in the turbine to form an expanded stream, a conduit for sending at least part of the expanded stream to the column system, a conduit for sending a second gaseous stream having the same nitrogen content as the first stream to be cooled in the heat exchanger, means for removing at least part of the second gaseous stream from an intermediate section of the heat exchanger at a second intermediate temperature and sending the second gaseous stream to the turbine to be expanded with the vaporized stream.

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 include utilization of a compression system, primary heat exchanger unit, plant processing units to separate and recover at least one desired fluid (e.g. nitrogen gas, argon gas, etc.). In some embodiments, the process can be configured so that fluid flows output from a low pressure column and/or high pressure column of the plant can provide a condensation duty or refrigeration duty that is utilized to process certain fluid flows for recovery of argon and/or nitrogen gases. Some embodiments can be configured to provide an improved recovery of argon and/or nitrogen as well as an improvement in operational efficiency by reducing an amount of power (e.g. electrical power) needed to recover the nitrogen and/or argon.