Ultra-high-purity oxygen production method and ultra-high-purity oxygen production apparatus
AssigneeL'Air Liquide, Societe Anonyme pour l'Etude et l’Exploitation des Procedes Georges Claude
InventorKenji HIROSE
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Abstract
An ultra-high-purity oxygen production method and apparatus are provide, in which the method can include a step in which feed oxygen comprising low-boiling-point components as impurities is introduced from a warm end of a main heat exchanger and cooled, then introduced into an oxygen rectification column, and product ultra-high-purity oxygen from which the low-boiling-point components have been removed is drawn as a gas or a liquid from a lower portion of the oxygen rectification column.
Claims8
An ultra-high-purity oxygen production method utilizing an air separation unit comprising a main heat exchanger, a nitrogen rectification column, a nitrogen condenser, an oxygen rectification column, and an oxygen vaporizer, wherein the method comprises the steps of:
- introducing a feed oxygen comprising low-boiling-point components as impurities to a warm end of the main heat exchanger, wherein the feed oxygen is cooled and at least partially liquefied, then introducing the feed oxygen into the oxygen rectification column, and ultra-high-purity oxygen from which the low-boiling-point components have been removed is withdrawn as a gas or a liquid from a lower portion of the oxygen rectification column or from the oxygen vaporizer;
- utilizing a heating fluid as a heating medium in the oxygen vaporizer, wherein the heating fluid is selected from the group consisting of:
- a portion of feed air cooled in the main heat exchanger, a portion of the feed oxygen cooled in the main heat exchanger, a liquid or gas withdrawn from a medium-pressure rectification column constituting the nitrogen rectification column, and combinations thereof;
- vaporizing liquefied oxygen supplied from a bottom portion of the oxygen rectification column;
- and
- supplying a vapour stream thereof to the bottom portion of the oxygen rectification column.
An ultra-high-purity oxygen production apparatus comprising:
- a main heat exchanger configured to receive a feed air and a feed oxygen;
- a first rectification column having a bottom portion into which the feed air, that has undergone heat exchange in the main heat exchanger, is introduced;
- at least one nitrogen condenser for condensing a nitrogen-rich gas drawn from a column top of the first rectification column;
- a second rectification column having a column top into which is introduced a nitrogen-rich gas condensed in the nitrogen condenser and/or a nitrogen-rich gas drawn from the column top of the first rectification column, after said nitrogen-rich gas has been cooled in a sub-cooler;
- an oxygen rectification column having a column top or a purification portion into which the feed oxygen that has undergone heat exchange in the main heat exchanger is introduced;
- an oxygen vaporizer which is arranged below a bottom portion of the oxygen rectification column and vaporizes liquefied oxygen while using, as a heating medium, one or more of:
- a portion of feed air cooled in the main heat exchanger, a portion of the feed oxygen cooled in the main heat exchanger, and a liquid or gas drawn from a medium-pressure rectification column constituting the nitrogen rectification column;
- and
- a sub-cooler for performing heat exchange of:
- an oxygen-rich liquid drawn from the bottom portion of the first rectification column, a purified gas condensed in the nitrogen condenser and/or a purified gas drawn from the column top of the first rectification column, and a nitrogen-rich gas drawn from the column top of the second rectification column.
An ultra-high-purity oxygen production apparatus comprising:
- a main heat exchanger into which feed air and feed oxygen are introduced;
- a nitrogen rectification column having a bottom portion into which the feed air, that has undergone heat exchange in the main heat exchanger, is introduced;
- a first nitrogen condenser for condensing a nitrogen-rich gas drawn from a column top of the nitrogen rectification column;
- a second nitrogen condenser for condensing the nitrogen-rich gas drawn from the column top of the nitrogen rectification column;
- an expansion turbine into which a gas drawn from a gas phase in the first nitrogen condenser is introduced, after said gas has been passed through a part of the main heat exchanger;
- a compressor for compressing a gas drawn from a gas phase in the second nitrogen condenser;
- an oxygen rectification column having a column top or a purification portion into which the feed oxygen that has undergone heat exchange in the main heat exchanger is introduced;
- and
- an oxygen vaporizer which is arranged below the bottom portion of the oxygen rectification column and vaporizes liquefied oxygen while using, as a heating medium, one or more of:
- a portion of feed air cooled in the main heat exchanger, a portion of the feed oxygen cooled in the main heat exchanger, and a liquid or gas drawn from the nitrogen rectification column.
Dependencies are inferred from the claim text.