Method and plant for providing a pressurized oxygen-rich, gaseous air product

An air separation plant which is configured for producing a pressurized, oxygen-rich, gaseous air product and comprises a rectification column system having a high-pressure column and a low-pressure column, as well as a main heat exchanger, a first turbine unit and a second turbine unit, wherein the air separation plant is configured to

• operate the high-pressure column in a first pressure range of from 4 to 7 bar, operate the low-pressure column in a second pressure range of from 1 to 2 bar, and compress at least a predominant proportion of a feed air quantity supplied overall to the rectification column system to a pressure in a third pressure range which is more than 3 bar above the first pressure range,
• supply a first partial quantity of the feed air quantity compressed to the pressure in the third pressure range to the first turbine unit at the pressure in the third pressure range or at a pressure in a fourth pressure range above the third pressure range and at a temperature in a first temperature range, decompress it to a pressure in the first pressure range using the first turbine unit, and feed it into the high-pressure column,
• supply a second partial quantity of the feed air quantity compressed to the pressure in the third pressure range to the second turbine unit at the pressure in the third pressure range or at a pressure in a fifth pressure range above the third pressure range and at a temperature in a second temperature range, decompress it to a pressure in the second pressure range using the second turbine unit, and feed it into the high-pressure column,
• remove oxygen-rich liquid from the rectification column system to provide the gaseous, pressurized, oxygen-rich air product, bring it to a pressure in a sixth pressure range of from 16 to 50 bar in the liquid state with heating to a temperature in a third temperature range, evaporate it in the main heat exchanger at the temperature in the third temperature range, and discharge it from the air separation plant, and
• remove a portion of less than 5% of all air products of the air separation plant removed from the air separation plant in an unevaporated and liquid state, wherein
• the second temperature range is selected such that a two-phase mixture having a liquid proportion of 5 to 15% forms at the outlet of the second turbine unit,
• wherein
• the air separation plant is configured, by removal from the main heat exchanger at suitable positions, so that the third temperature range is above the first temperature range and the second temperature range,
• the temperature in the first temperature range and the temperature in the second differ from each other by not more than 10 K, and
• the air separation plant is configured such that
• the first partial quantity of the feed air quantity compressed to the pressure in the third pressure range is provided at the pressure in the fourth pressure range and is thereby brought to the pressure in the fourth pressure range using a booster unit,
• the first turbine unit is used to drive the booster unit, and
• the second turbine unit is coupled to a generator or to a warm booster for air.