Enhancements to the distillation column system and cycles for an argon and nitrogen producing cryogenic air separation unit are provided. The enhancements include systems and methods for: (i) recovery of xenon and krypton; (ii) production of oxygen product substantially free of hydrocarbons; and (iii) improvement in the design and performance of the super-stage argon column. 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 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 system and method for cryogenic air separation arrangement having a booster loaded liquid turbine for expansion of a liquid air stream or other fluid having liquid-like densities is provided. The disclosed booster loaded liquid turbines are relatively small to provide an aerodynamic and speed match between the turbine and the coupled gas compressor. The coupled gas compressor is a supplemental booster compressor and may be a dedicated warm booster compressor or alternatively a cold booster compressor.

An air separation apparatus comprises: a first rectification column, a first condensing portion, a second rectification column, a third rectification column, a second condensing portion, a fourth rectification column, a third condensing portion, and a recycling pipe for recycling a gas drawn from the third condensing portion to the second rectification column. The air separation apparatus furthermore comprises: a branch pipe branching from the recycling pipe; and a control unit for controlling opening/closing of a valve so that a gas drawn from the third condensing portion is fed to the branch pipe for a predetermined period from the start of driving of the third condensing portion, and for controlling opening/closing of the valve so that the gas drawn from the third condensing portion is fed to the recycling pipe after the predetermined period has elapsed.

An air separation unit using cryogenic distillation comprises a first column, a second column thermally linked to the first column, a first argon column, a second argon column, means for sending cooled, compressed and purified air to at least the first column, means for sending at least one fluid enriched in nitrogen from the first column to the second column and at least one fluid enriched in oxygen from the first column to the second column, means for sending a gas enriched in argon from the second column to a first end of the first argon column, means for sending gas from a second end of the first argon column to a first end of the second argon column, means for removing argon rich fluid from a second end of the second argon column, a pump, means for removing argon enriched liquid from the first end of the second argon column and sending it to the second end of the first argon column via the pump, the first end of the first argon column being raised above the ground by a first supporting structure, the pump being positioned within the first supporting structure, such that the pump is at least partially underneath the first end of the first argon column.

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 nitrogen generating device comprises: a main heat exchanger; a nitrogen distillation column; at least one nitrogen condenser; a compressor; an expansion turbine; a rotation control unit for controlling rotation with respect to a rotating shaft connecting the compressor and the expansion turbine; a pressure measuring unit for measuring a pressure value of product nitrogen gas; and an optimum rotational speed calculation command unit which inputs the pressure value measured by the pressure measuring unit into a pre-installed rotational speed calculation function to calculate the rotational speed of the rotating shaft, and issues a command to the rotation control unit.

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.