Method for obtaining one or more air products and air separation system

Patent metadata

Field	Value
Publication number	US-12158303-B2
Application number	US-201917277595-A
Country	US
Kind code	B2
Filing date	Oct 8, 2019
Priority date	Oct 9, 2018
Publication date	Dec 3, 2024
Grant date	Dec 3, 2024

Abstract

A method for obtaining one or more air products, wherein an air separation system having a rectification column system is used, in which pressurized air is processed in an adjustable total air volume, wherein the total air volume is set to a first value during a first operating period and set to a second value that is different from the first value during a second operating period, and wherein the setting of the total air volume is changed from the first value to the second value in a third operating period from a first time to a second time. The second operating period is after the first operating period, the third operating period is between the first operating period and the second operating period. In the third operating period, a setting of a volume of a fluid, is changed from a third time up to a fourth time.

First claim

The invention claimed is:

1. A method for obtaining one or more air products using an air separation system having a rectification column system wherein pressurized air is processed in an adjustable total air volume of air to be processed, comprising:
setting the total volume of air to be processed to a first value during a first operating period and setting the total volume of air to be processed to a second value that is different from the first value during a second operating period,
wherein the setting of the total volume of air to be processed is changed from the first value to the second value in a third operating period from a first time and to a second time, and wherein the second operating period is after the first operating period, and the third operating period is between the first operating period and the second operating period,
wherein, in the third operating period, a setting of a volume of a fluid, which is formed from pressurized air via the rectification column system and transported into or out of the rectification column system, is changed from a third time and up to a fourth time, wherein the third time is before or after the first time and before the second time, and the fourth time is after the first time and the third time and before or after the second time, and a time period between the first time and the second time is set to not differ by more than 20% from a time period between the third time and the fourth time,
wherein the rectification column system has a high-pressure column operated at a first pressure level and a low-pressure column operated at a second pressure level below the first operating pressure, wherein a gaseous, nitrogen-rich overhead product is formed in the low-pressure column,
wherein the time period between the first time and the second time is set by changing the first time and/or the second time,
wherein the time period between the first time and the third time is set by changing the third time as a function of the setting of the time period between the first time and the second time, and
wherein the third time is after the first time, and the fourth time is after the second time, wherein a time period between the first time and the third time is lengthened when the period between the first time and the second time is shortened.

2. The method according to claim 1 , wherein the fluid, whose volume is changed in the third operating period, is a fraction of the gaseous, nitrogen-rich overhead product of the high-pressure column, which is liquefied and fed as a return flow to the low-pressure column.

3. The method according to claim 1 , wherein the first pressure level is 5 to 12 bar absolute pressure, and the second pressure level is 1.3 to 3.5 bar absolute pressure.

4. The method according to claim 1 , wherein one or more air products are formed in an adjustable product quantity, wherein the product quantity is set to a first value during the first operating period and to a second value which differs from the first value during the second operating period, and wherein the setting of the product quantity is changed from the first value to the second value during the third operating period from the first time and up to the second time point.

5. The method according to claim 4 , wherein the one or more air products is or are at least partially formed from the gaseous, nitrogen-rich overhead product of the high-pressure column.

6. The method according to claim 1 , wherein the first value of the total volume of air to be processed differs from the second value of the total volume of air to be processed by more than 5 and up to 30 percent.

7. The method according to claim 6 , wherein the total volume of air to be processed changes stepwise or continuously in during the third operating period.

8. The method according to claim 7 , wherein an average rate of change, during the stepwise change, or a rate of change, during the continuous change, of the total air volume in the third operating period is from 0.1 to 10 percent per minute.

9. The method according to claim 1 , wherein the rectification column system has one or more rectification columns designed to obtain an argon-rich air product, and wherein argon-rich air product is formed in the process.

10. An air separation system configured for obtaining one or more air products comprising:
a rectification column system,
wherein the air separation system having said rectification column system is configured to process pressurized air in an adjustable total air volume in the rectification column system and a total volume of air to be processed is set to a first value during a first operating time period and to a second value different from the first value during a second operating time period, and to change the setting of the total volume of air to be processed from the first value to the second value in a third operating period from a first time and up to a second time,
wherein the second operating period is after the first operating period, and the third operating period is between the first operating period and the second operating period,
air separation system further comprising a control unit that, in the third operating period, is programmed to change a setting of a volume of a fluid, formed from pressurized air via the rectification system and transported into or out of the rectification column system from a third time and up to a fourth time, wherein the third time is before or after the first time and before the second time, and the fourth time is after the first time and the third time and before or after the second time, and to set a time period between the first time and the second time such that it does not differ by more than 20% from a time period between the third time and the fourth time,
wherein the rectification column system has a high-pressure column operated at a first pressure level and a low-pressure column operated at a second pressure level below the first operating pressure, wherein a gaseous, nitrogen-rich overhead product is formed in the low-pressure column,
wherein the time period between the first time and the second time is set by changing the first time and/or the second time,
wherein a time period between the first time and the third time is set by changing the third time as a function of the setting of the time period between the first time and the second time, and
wherein the third time is after the first time, and the fourth time is after the second time, wherein a time period between the first time and the third time is lengthened when the period between the first time and the second time is shortened.

11. The air separation system according to claim 10 , wherein the control unit is programmed to execute a method for obtaining one or more air products, using said air separation system having the rectification column system, in which method the total volume of air to be processed is set to said first value during said first operating period and set to said second value during said second operating period, wherein the setting of the total air volume is changed from the first value to the second value in said third operating period from said first time and to said second time, and wherein the second operating period is after the first operating period, and the third operating period is between the first operating period and the second operating period, and wherein, in the third operating period, the setting of the volume of a fluid is changed from said third time and up to said fourth time, wherein the third time is before or after the first time and before the second time, and the fourth time is after the first time and the third time and before or after the second time, an

Assignees

• Linde Gmbh

Inventors

• Schwenk Dirk
• Golubev Dimitri

Classifications

• F25J2290/62

  Details of storing a fluid in a tank · CPC title

• F25J2250/50

  One fluid being oxygen · CPC title

• F25J2250/40

  One fluid being air · CPC title

• F25J3/0449

  for rapid load change of the air fractionation unit · CPC title

• F25J3/04412

  in a classical double column flowsheet, i.e. with thermal coupling by a main reboiler-condenser in the bottom of low pressure respectively top of high pressure column · CPC title