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US 4,568,528 AGranted
Process to produce a krypton-xenon concentrate and a gaseous oxygen product
AssigneeUnion Carbide Corporation
InventorHarry Cheung
Life of this patent
Estimating the term…
Abstract
A krypton-xenon concentration process which also produces substantially rare gas-free oxygen gas while requiring a stripping column substantially smaller than is required by conventional process wherein feed liquid is provided directly to a reboiling zone and only the vapor from the reboiling zone is passed through the stripping column.
Claims18
A process for the production of a krypton-xenon concentrate and the recovery of a gaseous product substantially free of rare gases, comprising:
- (1) taking from an air separation plant a feed liquid comprising oxygen, krypton and xenon wherein the oxygen in the feed liquid comprises from about 5 to 40 percent of the oxygen from the air separation plant and providing said feed liquid to a reboiling zone to form a reboiling liquid;
- (2) partially vaporizing the reboiling liquid to produce a vapor, and a liquid krypton-xenon concentrate;
- (3) recovering krypton-xenon concentrate;
- (4) introducing into a stripping column, reflux liquid having a krypton-xenon concentration less than that in said vapor;
- (5) passing said vapor against the reflux liquid downflowing in the stripping column;
- (6) stripping krypton and xenon from the vapor into the reflux liquid to produce a lean vapor and a richer liquid;
- (7) passing the richer liquid to the reboiling zone to form part of the reboiling liquid;
- (8) withdrawing lean vapor from the stripping column;
- (9) recovering withdrawn lean vapor as gaseous product substantially free of rare gases;
- and
- (10) recovering the major portion of the oxygen as oxygen gas product directly from the air separation plant, thereby enabling the employment of a stripping column of considerably smaller size then is required for conventional krypton-xenon concentration processes.
8 more elements
A process for the production of a krypton-xenon concentrate and the recovery of gaseous product substantially free of rare gases, comprising:
- (1) providing feed air to a cryogenic rectification air separation plant comprising a higher pressure column and a lower pressure column in heat exchange relation;
- (2) withdrawing a first liquid comprising oxygen, krypton and xenon from the area of heat exchange relation and providing said withdrawn liquid to a reboiling zone to form a reboiling liquid;
- (3) partially vaporizing the reboiling liquid to produce a vapor, and a liquid krypton-xenon concentrate;
- (4) recovering krypton-xenon concentrate;
- (5) withdrawing a second liquid from the lower pressure column at a point above the point where the first liquid is withdrawn, said second liquid having a krypton-xenon concentration less than that in the vapor produced in the reboiling zone, and introducing said second liquid into a stripping column as reflux liquid;
- (6) passing said vapor against the reflux liquid downflowing in the stripping column;
- (7) stripping krypton and xenon from the vapor into the reflux liquid to produce a lean vapor and a richer liquid;
- (8) passing the richer liquid to the reboiling zone to form part of the reboiling liquid;
- (9) withdrawing lean vapor from the stripping column;
- (10) recovering withdrawn lean vapor as gaseous product substantially free of rare gases;
- (11) withdrawing from the lower pressure column, at a point between the points from where the first and second liquids are withdrawn, a gaseous stream;
- and
- (12) recovering said gaseous stream as product oxygen.
10 more elements
Dependencies are inferred from the claim text.