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US 12,716,651 B2Granted
Air separation unit and air separation method
AssigneeL'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
InventorKenji Hirose
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Abstract
The method for reducing or removing non-volatile impurities in a high-purity oxygen liquid comprises: an oxygen vaporization step for vaporizing a high-purity oxygen liquid obtained from a high-purity oxygen rectification column in an air separation unit for producing the high-purity oxygen liquid; and an oxygen recondensing step for recondensing oxygen gas vaporized in the oxygen vaporization step. This method may also comprise a high-purity oxygen liquid extraction step for extracting a condensate obtained in the oxygen recondensing step.
Claims14
An air separation unit comprising:
- a. a main heat exchanger configured to cool feed air via indirect heat exchange;
- b. a nitrogen rectification column in fluid communication with the main heat exchanger and configured to receive the feed air from the main heat exchanger after cooling, the nitrogen rectification column having a first nitrogen rectifying portion in which high-boiling-point components are concentrated, and a second nitrogen rectifying portion in which low-boiling-point components are concentrated, the first nitrogen rectifying portion having an upper rectifying portion, an intermediate portion and a lower rectifying portion;
- c. first and second condensers into which a gas drawn from a column top of the second nitrogen rectification portion is introduced, the first and second condensers being fluidly connected so as to condense the gas drawn from the column top of the second nitrogen rectification portion and return said gas to the column top of the second nitrogen rectification portion;
- d. a high-purity oxygen rectification column;
- e. a first pipeline fluidly connected to the first nitrogen rectifying portion and configured to introduce an oxygen-containing liquid containing non-volatile impurities, drawn from the first nitrogen rectifying portion, into an upper rectifying portion or a column top of the high purity oxygen rectification column;
- f. a liquid feed pump fluidly connected to an oxygen rich pipeline configured to feed an oxygen-rich liquid collected in a bottom of the second nitrogen rectification portion to a column top of the first nitrogen rectifying portion;
- g. an oxygen vaporizer which is arranged in a lower portion of the high-purity oxygen rectification column and is configured to generate a vapor stream of oxygen gas;
- and
- h. an oxygen recondenser fluidly connected to receive a portion of the vapor stream of oxygen gas generated in the oxygen vaporizer, the oxygen recondenser being configured to condense the portion of the vapor stream of oxygen gas.
6 more elements
An air separation unit comprising:
- a. a main heat exchanger configured to cool feed air via indirect heat exchange;
- b. a nitrogen rectification column comprising an intermediate or lower rectifying portion into which the feed air that has passed through the main heat exchanger is introduced;
- c. first and second condensers into which a gas drawn from a column top of the nitrogen rectification column is introduced, the first and second condensers being fluidly connected so as to condense this gas and return it to the column top;
- d. a reflux pipeline configured to feed an oxygen-rich liquid drawn from a bottom of the nitrogen rectification column to the second condenser;
- e. a second reflux pipeline configured to feed the oxygen-rich liquid from the second condenser to the first condenser;
- f. a high-purity oxygen rectification column having a first oxygen rectifying portion in which high-boiling-point components are concentrated, and a second oxygen rectifying portion in which low-boiling-point components are concentrated;
- g an oxygen vaporizer which is arranged in a lower portion of the second oxygen rectifying portion and serves to generate a vapor stream of oxygen gas;
- and
- h. an oxygen recondenser fluidly connected to the oxygen vaporizer and configured to receive a portion of the oxygen gas generated in the oxygen vaporizer, the oxygen recondenser further configured to condense this oxygen gas;
- and
- i. a liquid feed pump fluidly connected to a pipeline configured to feed an oxygen-rich liquid containing non-volatile impurities collected in a bottom of the first oxygen rectifying portion to a column top of the second oxygen rectifying portion.
8 more elements
A method for reducing or removing non-volatile impurities in high-purity oxygen liquid within an air separation system, the method comprising:
- separating air in a rectification column system to produce an oxygen-containing liquid;
- transferring a portion of the oxygen-containing liquid within the rectification column system using a liquid feed pump, wherein the liquid feed pump introduces non-volatile impurities into the oxygen-containing liquid;
- receiving the oxygen-containing liquid containing non-volatile impurities in an oxygen vaporizer;
- vaporizing the oxygen-containing liquid in the oxygen vaporizer to produce a vaporized oxygen stream and a liquid phase within the oxygen vaporizer, wherein the liquid phase comprises the non-volatile impurities;
- and
- recondensing the vaporized oxygen stream in an oxygen recondenser to produce a high-purity oxygen liquid substantially free of the non-volatile impurities.
3 more elements
Dependencies are inferred from the claim text.