Cryogenic Air Separation Method and Air Separation Unit

An air separation unit comprising a rectification column, the air separation unit being adapted to compress, cool and rectify feed air in the rectification column obtaining an overhead gas, wherein means are provided which are adapted to condense a part of the overhead gas of the rectification column using fluid withdrawn from the rectification column, wherein means are provided which are adapted to use the condensed overhead gas at least in part as a liquid reflux to the rectification column, wherein means are provided which are adapted to compress and reintroduce into the rectification column a first part of the fluid which is used for cooling the overhead gas of the rectification column after its use for cooling, and wherein means are provided which are adapted to expand and withdraw from the air separation unit a second part of the fluid which is used for cooling the overhead gas of the rectification column after its use for cooling, wherein compressing the first part of the fluid which is used for cooling the overhead gas of the rectification column a compressor which is coupled to an electric motor via a first gearbox is provided, in that for expanding the second part of the fluid which is used for cooling the overhead gas of the rectification column an expansion turbine which is coupled to an electric generator via a second gearbox is provided, and in that the first gearbox and the second gearbox are provided with an identical design including identical reduction or multiplication ratios in the first gearbox and the second gearbox.