L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des

Jean Louise

Daniel Gary

Jean-Yves Thonnelier

Bertrand Mollaret

Henry Ledon

Panayotis Cocolios

Olivier Delobel

Philippe Cornut

Guy Senechal

Process for preparing ultra-pure nitrogen containing less than 100 ppb (parts per billion) impurities, characterized in that at least the impurities consisting of carbon monoxide (CO) and/or hydrogen (H.sub.2) are removed by passing the gas from which at least one of these two components has to be removed, over a bed of particles including a metallic element namely copper (Cu) and/or ruthenium (Ru) and/or rhodium (Rh) and/or palladium (Pd) and/or osmium (Os) and/or iridium (Ir) and/or platinum (Pt) supported on a particulate support, by the technique of ion exchange and/or by the technique of impregnation. This technique enables to produce ultra-pure nitrogen by using it either with nitrogen obtained by distillation, or air to be distilled as an additional step for the removal of CO.sub.2 and H.sub.2 O. A device for carrying out the process constitutes another object of the invention.

Apparatus for preparing ultra-pure nitrogen

The invention concerns a process for removing gaseous hydrides from a solid support of metallic oxides, which consists in causing a gas flow to circulate, at room temperature, on a solid support comprising at least copper and chromium and having a specific area lower than or equal to 100 m.sup.2 /g. This process may be used for the destruction of gaseous hydrides from the industry of semi-conductors, for example silanes, arsine, phosphine, diborane, germane, stannane, gallane, stibine, and hydrogen telluride, selenide and sulfide.

Process for removing gaseous hydrides from a solid support comprising

Process and apparatus for preparing ultra-pure nitrogen containing less than 100 ppb (parts per billion) impurities, characterized in that at least the impurities consisting of carbon monoxide (CO) and/or hydrogen (H.sub.2) are removed by passing the gas from which at least one of these two components has to be removed, over a bed of particles including a metallic element namely copper (Cu) and/or ruthenium (Ru) and/or rhodium (Rh) and/or palladium (Pd) and/or osmium (Os) and/or iridium (Ir) and/or platinum (Pt) supported on a particulate support, by the technique of ion exchange and/or by the technique of impregnation. This technique enables to produce ultra-pure nitrogen by using it on air to be distilled as an additional step for the removal of CO.sub.2 and H.sub.2 O.

Process for preparing ultra-pure nitrogen

Process for treatment of gaseous effluents containing sulfur dioxide

There is described a process for the purification of gaseous effluents containing oxides of sulphur before discharge of the gaseous effluent into the atmosphere. The process is carried out in at least two separate stages of oxidation using ozonised oxygen in the presence of a catalytic quantity of an ion of a transition metal and in a manner such that the ozonised oxygen does not contact the gaseous effluent. The ozone is generally employed in the proportion of one mole of ozone to 15 to 20 moles of impurity to be oxidised.

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Villejuif, France

Jean Louise