摘要 |
The invention relates to a method for producing acid phthalic anhydride by catalytic gas phase oxidation of o-xylol or naphthalene or o-xylol/naphthalene mixtures with a molecular gas containing oxygen on a shell catalyst consisting of an inert, non-porous carrier material to which a coating of a catalytically active mass containing titanium dioxide and vanadium pentoxide is applied, wherein a catalyst is used whose catalytically active mass consists of 3 to 6 wt. % of vanadium pentoxide calculated as V2O5, 0.3 to 0.5 wt. % of a cesium compound calculated as Cs, and the remainder up to 100 wt. % of titanium dioxide anastase modification, in the presence or absence of a catalyst in the form of a shell differing from the above-mentioned catalyst which is used to produce gas-phase oxidation of o-xylol or naphthalene or o-xylol/naphthalene mixtures. In the presence of a second catalyst of this type, said catalyst is introduced to the reactor with the catalyst of the above-mentioned composition in a combined charge.
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申请人 |
BASF AG, 67063 LUDWIGSHAFEN, DE |
发明人 |
HEFELE, GERHARD, 67354 ROEMERBERG, DE;KRATZER, OTTO, DR., 67240 BOBENHEIM-ROXHEIM, DE;SCHEIDMEIR, WALTER, DR., 67117 LIMBURGERHOF, DE;ULRICH, BERNHARD, DR., 67278 BOCKENHEIM, DE |