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

Abstract

The invention relates to a high-atmospheric-pressure method for producing a pressurized oxygen-rich, gaseous air product. A first partial quantity of the feed air quantity is supplied at a temperature in a first temperature range to a first turbine unit (5), decompressed using same, and fed into a high-pressure column (111). A second partial quantity of the feed air quantity is supplied at a temperature in a second temperature range to a second turbine unit (6), decompressed using same, and fed into a low-pressure column (12). The pressurized, oxygen-rich air product is provided as an internal compression product at 16 to 50 bar, wherein evaporation is effected proceeding from a temperature in a third temperature range. The third temperature range lies above the first and second temperature range, the second temperature range is selected such that a two-phase mixture with a liquid proportion of 5 to 15% forms at the outlet of the second turbine unit (6), the temperature in the first temperature range and the temperature in the second differ from each other by not more than 10 K, and a portion of less than 5% of all air products removed from the air separation plant (100) is removed from the air separation plant in an unevaporated and liquid state. The first turbine unit is braked by a cold compressor (4), the second by a generator (G) or a warm booster. The invention also relates to an air separation plant (100).

1 . A method for producing a pressurized, oxygen-rich, gaseous air product using an air separation plant comprising a rectification column system having a high-pressure column and a low-pressure column and a main heat exchanger, a first turbine unit, and a second turbine unit, wherein
 the high-pressure column is operated in a first pressure range of from 4 to 7 bar, the low-pressure column is operated in a second pressure range of from 1 to 2 bar, and at least a predominant portion of a total feed air quantity supplied to the rectification column system is compressed to a pressure in a third pressure range which is more than 3 bar above the first pressure range,   a first partial quantity of the feed air quantity compressed to the pressure in the third pressure range is supplied 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, decompressed to a pressure in the first pressure range using the first turbine unit, and fed into the high-pressure column,   a second partial quantity of the feed air quantity compressed to the pressure in the third pressure range is supplied 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, decompressed to a pressure in the second pressure range using the second turbine unit, and fed into the high-pressure column,   oxygen-rich liquid is withdrawn from the rectification column system to provide the gaseous, pressurized, oxygen-rich air product, brought to a pressure in a sixth pressure range of from 16 to 50 in a liquid state, supplied to the main heat exchanger, evaporated therein at the temperature in the third temperature range and discharged from the air separation plant, 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,   a proportion of less than 5% of all air products withdrawn from the air separation plant is withdrawn from the air separation plant in an unevaporated and liquid state   wherein   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,   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.   
     
     
         2 . The method according to  claim 1 , wherein the first and second temperature ranges are 110 to 140 K. 
     
     
         3 . The method according to  claim 1 , wherein the third temperature range is more than 10 K above the second temperature range. 
     
     
         4 . The method according to  claim 1 , wherein the booster unit is formed by a cold compressor. 
     
     
         5 . The method according to  claim 1 , wherein the first partial quantity of the feed air quantity compressed to the pressure in the third pressure range is cooled in a first cooling step in the main heat exchanger before it is brought to the pressure in the fourth pressure range using the booster unit, and wherein the first partial quantity of the feed air quantity compressed to the pressure in the third pressure range can be cooled in a second cooling step in the main heat exchanger after it has been brought to the pressure in the fourth pressure range using the booster unit, wherein the second cooling step comprises cooling to the temperature in the first temperature range. 
     
     
         6 . The method according to  claim 5 , wherein a third partial quantity of the feed air quantity compressed to the pressure in the third pressure range is subjected to the first cooling step together with the first partial quantity of the feed air quantity compressed to the pressure in the third pressure range and brought to the pressure in the fourth pressure range using the booster unit, wherein the third partial quantity of the feed air quantity compressed to the pressure in the third pressure range is liquefied at the pressure in the fourth pressure range in the main heat exchanger, subsequently decompressed, and fed into the high-pressure column. 
     
     
         7 . The method according to  claim 1 , wherein the second partial quantity of the feed air quantity compressed to the pressure in the third pressure range is provided at the pressure in the fifth pressure range and is thereby brought to the pressure in the fifth pressure range using a further booster unit. 
     
     
         8 . The method according to  claim 1 , wherein the two-phase mixture forming at the outlet of the second turbine unit is supplied to a phase separation and is then fed into the low-pressure column in a separate phase. 
     
     
         9 . The method according to  claim 1 , wherein the two-phase mixture forming at the outlet of the second turbine unit is fed biphasically into the low-pressure column. 
     
     
         10 . 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.   
     
     
         11 . The air separation plant according to  claim 10 , wherein the booster unit is formed by a cold compressor. 
     
     
         12 . The air separation plant according to  claim 11 , which is configured to carry out a method for producing a pressurized, oxygen-rich, gaseous air product using the air separation plant, wherein
 the high-pressure column is operated in a first pressure range of from 4 to 7 bar, the low-pressure column is operated in a second pressure range of from 1 to 2 bar, and at least a predominant portion of a total feed air quantity supplied to the rectification column system is compressed to a pressure in a third pressure range which is more than 3 bar above the first pressure range,   a first partial quantity of the feed air quantity compressed to the pressure in the third pressure range is supplied 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, decompressed to a pressure in the first pressure range using the first turbine unit, and fed into the high-pressure column,   a second partial quantity of the feed air quantity compressed to the pressure in the third pressure range is supplied 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, decompressed to a pressure in the second pressure range using the second turbine unit, and fed into the high-pressure column,   oxygen-rich liquid is withdrawn from the rectification column system to provide the gaseous, pressurized, oxygen-rich air product, brought to a pressure in a sixth pressure range of from 16 to 50 in a liquid state, supplied to the main heat exchanger, evaporated therein at the temperature in the third temperature range and discharged from the air separation plant, 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,   a proportion of less than 5% of all air products withdrawn from the air separation plant is withdrawn from the air separation plant in an unevaporated and liquid state   wherein   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,   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.