21.
    发明专利
    未知

    公开(公告)号:ID26586A

    公开(公告)日:2001-01-18

    申请号:ID20002423

    申请日:1999-05-10

    Applicant: BASF AG

    Abstract: In a process for preparing phthalic anhydride by catalytic gas-phase oxidation of o-xylene/naphthalene mixtures by molecular oxygen, use is made of a catalyst I in a first zone on the gas inlet side which makes up from 25 to 75 percent by volume of the total catalyst volume, comprising, in each case based on the catalytically active composition, from 1 to 10% by weight of vanadium oxide (calculated as V205), from 1 to 10% by weight of antimony oxide (calculated as Sb203) and from 80 to 98% by weight of titanium dioxide of the anatase type having a BET surface area of from 13 to 28 m2/g and also from 0.05 to 1% by weight of cesium (calculated as Cs) applied to a steatite support and a catalyst II in a second zone which makes up the remaining 75 to 25 percent by volume of the total catalyst volume, comprising, in each case based on the catalytically active composition, from 1 to 10% by weight of vanadium oxide (calculated as V205), from 1 to 10% by weight of antimony oxide (calculated as Sb203) and from 80 to 98% by weight of titanium dioxide of the anatase type having a BET surface area of from 13 to 28 m2/g and from 0.01 to 1% by weight of phosphorus oxide (calculated as P) and also from 0.01 to 0.2% by weight of cesium (calculated as Cs) applied to a steatite support, wherein the cesium content of the catalyst II is less than 15% by weight of the cesium content of the catalyst I and the catalyst I and the catalyst II have been prepared without addition of compounds of niobium.

    22.
    发明专利
    未知

    公开(公告)号:DE19823275A1

    公开(公告)日:1999-12-02

    申请号:DE19823275

    申请日:1998-05-26

    Applicant: BASF AG

    Abstract: The invention relates to a method for producing phthalic anhydride by means of catalytic vapor-phase oxidation of o-xylol/naphthalene mixtures with molecular oxygen while using a catalyst (I) situated in a first layer on the gas entry side, said layer amounting to 25 to 75 percentage by volume of the total catalyst volume, containing, each time with regard to the catalytically effective mass, 1 to 10 wt.% vanadium oxide (calculated as V2O5), 1 to 10 wt.% antimony oxide (calculated as Sb2O3) and 80 to 98 wt.% titanium dioxide of the anatase type with a BET surface of 13 to 28 m /g, and 0.05 to 1 wt.% cesium (calculated as Cs), deposited on a steatite support. In addition, the phthalic anhydride is produced by using a catalyst (II) situated in a second layer, said layer amounting to the remaining 75 to 25 percent by volume of the total catalyst volume, containing, each time with regard to the catalytically effective mass, 1 to 10 wt.% vanadium oxide (calculated as V2O5), 1 to 10 wt.% antimony oxide (calculated as Sb2O3) and 80 to 98 wt.% titanium dioxide of the anatase type with a BET surface of 13 to 28 m /g, 0.01 to 1 wt.% phosphorous oxide (calculated as P) and 0.01 to 0.2 wt.% cesium (calculated as Cs), deposited on a steatite support. The cesium content of catalyst (II) is less than 15 wt.% of the cesium content of catalyst (I), and catalyst (I) and catalyst (II) are produced without adding compounds of niobium.

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