System and method for generation of oxygen by low-temperature air separation

A method or generation of oxygen by low-temperature air separation in a distillation column system that comprises

• a high-pressure column and a low-pressure column,
• a main condenser which is constructed as a condenser-evaporator, wherein a liquefaction space of the main condenser is flow-connected to the top of the high-pressure column and an evaporation space of the main condenser is flow-connected to the low-pressure column and
• an auxiliary column,
• wherein
• an oxygen stream is taken off from the low-pressure column and is recovered as oxygen product,
• a gaseous fraction, the oxygen content of which is equal to that of air or higher, is introduced into a sump region of the auxiliary column,
• a liquid stream from the high-pressure column, the main condenser or the low-pressure column is applied as reflux to the top of the auxiliary column, wherein
• the liquid stream has a nitrogen content that is at least equal to that of air,
• characterized in that
• an argon-rich stream is introduced from an intermediate site of the low-pressure column into an argon removal column,
• reflux for the argon removal column is generated in an argon removal column top condenser that is constructed as a condenser-evaporator, wherein a
• liquefaction space of the argon removal column top condenser is flow-connected to the top of the argon removal column,
• crude oxygen is introduced from a sump of the high-pressure column into an evaporation space of the argon removal column top condenser,
• wherein
• the low-pressure column is arranged beside the high-pressure column,
• the main condenser is arranged over the high-pressure column,
• the auxiliary column is arranged over the main condenser,
• the argon removal column is arranged over the auxiliary column and
• the argon removal column top condenser is arranged over the argon removal column.