Patent ID: 6693056
Filing Date: 2004-02-17
Classification: B01J

Abstract:
A process for passivating a pyrophorous solid, wherein the solida) is treated in a CO2â€”N2 gas mixture having a CO2 content of 0.5 to 10% by volume at temperatures of 91Â° C. to 350Â° C. for at least 30 minutes, b) then cooled down to a temperature of not more than 90Â° C. in the CO2â€”N2 gas mixture of step a), c) after reaching the temperature of step b) oxygen is added to the CO2â€”N2 gas mixture in a first passivation phase to a content of 0.2 to 1.5% by volume and the catalyst is treated in the CO2â€”N2â€”O2 gas mixture for at least 30 minutes with agitation, d) and then in a second passivation phase, with agitation, the CO2 content in the CO2â€”N2â€”O2 gas mixture is lowered to <0.1% by volume and the oxygen content is raised to 1.5â€”21% by volume.