Linde Aktiengesellschaft

Linde Gas Aktiengesellschaft

J&uuml;rgen Voit

Wilhelm Rohde

Gerhard Pompl

Erich Hahn

Eric Hahn

The process and the apparatus serve for the low-temperature fractionation of air. Compressed and prepurified feed air ( ) is introduced into a rectification system for nitrogen-oxygen separation which has a pressure column ( ). At least a part of the compressed and prepurified feed air is fed ( ) to the pressure column ( ). An oxygen-enriched fraction ( ) is taken off from the pressure column ( ) and passed ( ) to a further working step ( ) within the rectification system. The oxygen-enriched fraction ( ) is taken off at least one theoretical or actual plate ( ) above the point at which the compressed and prepurified feed air ( ) is fed to the pressure column. From the bottom of the pressure column ( ) a purge fraction ( ) is removed in the. liquid state, fed in the liquid state to a purification stage ( ), in which N O is removed, and is taken off from the purification stage ( ) as purified purge fraction ( ).

Method and device for cryogenic air separation

The invention relates to a method for extracting xenon and eventually also krypton from a liquid oxygen (LOX) charge, as it accrues in a cryogenic air separation system (LZA) during a rectification of the air, mostly as a bottom product of a low-pressure, column, namely with xenon (Xe), krypton (Kr) and hydrocarbons (C H ) in a small concentration and approximately 99 mol % oxygen (O ). According to the inventive method, the LOX charge is fed to a first column, the oxygen of the LOX charge is extensively removed by stripping with an inert gas, and is extracted in the top gas, whereas the inert gas is withdrawn in the form of a liquid from the bottom of the first column with little O and nearly the total mass of C H , Kr, Xe. According to the invention, the liquid discharge is fed to a second column without prior catalytic and/or adsorptive removal of C H . A Kr fraction is extracted as top gas of the second column, and an Xe fraction is withdrawn from the bottom of the second column. The method can be used in a device for extracting Xe and/or Kr in an air separation system (LZA). The device can be arranged in a transportable container.

Method for extracting xenon

The invention relates to a process and a liquefier for the production of liquid air with an oxygen content of between 16 and 21 mol % in a low-temperature process, whereby atmospheric air is used as a feed gas; in a warm part of the process, H,O, carbon dioxide and contaminants entrained in the air are removed in a purification step, e.g. adsorption; cold is produced by compression and engine expansion of process streams. Liquid air is obtained as a liquid head product in a cold part of the process by low-temperature rectification in a column having less than four theoretical plates. In addition, a liquid bottoms product is obtained in the rectification, used exergetically and vented as a warm residual gas into the atmosphere or used at least partially in the purification step.

Process and liquefier for the production of liquid air

In a process for the production of a pressurized gaseous product by low-temperature separation of air, which is at times done in a gas operation and at times in a combined operation, whereby in the gas operation and in the combined operation (a) purified charging air is cooled under pressure, partially liquefied, and subjected to rectification to produce gaseous and liquid fractions, (b) extremely cold liquid of at least one of the liquid fractions from the rectification is evaporated under elevated pressure by indirect heat exchange with feed air, heated, and obtained as a pressurized gaseous product, whereby in combined operation, (c) the cold that is required for this purpose is generated in an air-refrigeration cycle, by air being compressed in the refrigeration cycle and work expanded, in which case heat is removed from the air, and the actively depressurized air that is partially in countercurrent is heated again with the charging air that is to be cooled and then repressurized, (d) extremely cold liquid is produced and at least partially stored. During gas operation, the air throughput in the refrigeration cycle is reduced to zero, and extremely cold stored liquid is used to compensate for cold losses that are no longer covered by the refrigeration cycle. In the corresponding apparatus, during gas operation the compressor(s) for the supply of recycle air are switched off in a compressor station for recycle air and throttle air.

Growing community of inventors

Schondorf, Germany

Jürgen Voit

Growing community of inventors

Schondorf, Germany

J&uuml;rgen Voit

Jürgen Voit