Regeneration of pentasil zeolite catalysts using ozone and oxygen

Abstract

A novel procedure for the removal of carbonaceous deposits from zeolites using ozone-enriched oxygen is described. Pentasil zeolites (SiO₂/Al₂O₃ mole ratios 35, 70) were studied and deactivated using methanol conversion to hydrocarbons and o-xylene isomerisation. Low temperature ozone reactivation was found to restore the catalyst activity for these reactions and hence can be considered as an alternative procedure to high temperature oxygen reactivation currently utilised industrially. Ozone reactivation was found to increase slightly the catalyst lifetime and also to reduce the initial methane yield when compared with oxygen reactivation.