Linde Aktiengesellschaft

Solvay Interox (societe Anonyme)

Karl Baur

Heinz Karwat

Michael Heisel

Hans Becker

Ulrike Wenning

Eberhard Lassmann

Karl-Heinz Gregor

Peter Haussinger

Michael Huala

Farsin Yadegardjam

Hermann Schwarz

Gerhard Luft

Hartmut Neumann

Hans-Peter Langebach

Erich Dannhorn

Ludwig Fruhstorfer

Hans-Jurgen Neubert

Krypton and/or xenon are extracted from a krypton-xenon concentrate by means of distillation, for example, a krypton-xenon concentrate obtained from a low-temperature air separation unit. To remove fluorine- and/or chlorine-containing contaminants, especially fluorocarbons, CF.sub.4 and/or SF.sub.6, the krypton-xenon concentrate, a krypton stream and/or a xenon stream are purified in a solid sorbent that contains phyllosilicates.

Process for krypton an xenon extraction

For selectively removing nitrogen oxides from a carrier gas that contains hydrocarbons, the nitrogen oxides are removed by chemisorption on metal oxides, without the occurrence of undesirable secondary reactions. The metal oxides are preferably formed from metals of the 6th to 8th subgroups, whereby manganese dioxide (MnO.sub.2,) is especially preferred as a metal oxide. The process can be conducted with one or more reactor beds, which preferably operate at 10 to 40.degree. C. and are regenerated with nitrogen at a temperature of 130 to 170.degree. C. By removing nitrogen oxides from an olefin-rich gas, for example from the waste gas of an FCC unit, the resultant gas can then be fed to a cryogenic olefin extraction stage without danger of explosion. Such a waste gas contains unsaturated hydrocarbons, hydrogen, carbon monoxide, and oxygen, the oxygen having a concentration preferably between 100 and 5000 mol ppm.

Removal of nitrogen oxides from gases

Process for treating a medium containing organic constituents

For the removal of sulfur compounds, especially H.sub.2 S, from gaseous mixtures, said mixtures are scrubbed with a physical solvent which is later regenerated and reused. To the solvent are added (a) an oxidizing agent for converting the sulfur compounds into elemental sulfur, and (b) additive means for increasing the settling rate of the thus-formed sulfur.

Settling of sulfur in sulfide removal process

For the removal of sulfur compounds, especially H.sub.2 S, from gases that contain hydrocarbons, and/or CO.sub.2, the gases are scrubbed with a physical solvent, which is to be regenerated and reused. To obtain sulfur free of hydrocarbons, as well as a practically sulfur-free LPG fraction and optionally a C.sub.5+ fraction, an oxidizing agent is added to the solvent for reacting the sulfur compounds to elemental sulfur, and the sulfur is separated. The concomitantly absorbed hydrocarbons and/or CO.sub.2 can then be desorbed from the separated solvent by physical regeneration and can be recovered.

Removal of sulfur compounds from gases

For preventing the fouling and/or plugging of apparatus with metallic sulfides in the processing and purification of synthesis gases contaminated with metal carbonyls, wherein the synthesis gases are scrubbed with a physical solvent, which solvent is regenerated and reused, an organic phosphite, e.g., trimethyl phosphite, and/or an organic phosphine, e.g., triethyl phosphine or triphenyl phosphine, is added as a complexing agent to the scrubbing media, preferably in between the scrubbing and absorption regenerating steps.

Process for preventing the plugging of installations with metallic

In the removal of sour gases by scrubbing with an aqueous alkali metal salt solution, e.g. a solution of K.sub.2 CO.sub.3, the circulating scrubbing liquid is gradually contaminated with organic acids, especially formic acid, which in turn ties up K.sup.+ as the formate which is ineffective for scrubbing purposes. To remove the organic acids, at least a partial stream of the circulating scrubbing liquid is subjected to an oxidation step under conditions leading to the oxidation of the salts of the organic acids, thereby liberating the bound alkali metal ions. If the scrubbing liquid contains an oxidizable activator, the latter can be extracted prior to oxidation of the scrubbing liquid and added back subsequent to the oxidation.

Process for removal of sour gases by scrubbing

A process for scrubbing acid gases in which carbon dioxide and hydrogen sulfide, for example, are scrubbed from gas mixtures which also contain polymerizable organic components, in which an aqueous alkanolamine, such as ethanolamine, is used as the scrubbing liquid. The scrubbing liquid is heated, regenerated, cooled and returned to the scrubber and the polymerizable component or the polymer formed therefrom is removed by treating the scrubbing liquid with an organic solvent which is water immiscible. The extraction treatment by the organic solvent, according to the invention, is carried out after the heating and before the regeneration of the charged scrubbing liquid at a temperature of the latter which is just below the boiling point of the liquid mixture formed by the scrubbing liquid and the organic extracting solvent.

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Baierbrunn, Germany

Karl Baur