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    2.
    发明专利
    未知

    公开(公告)号：DE1150970B

    公开(公告)日：1963-07-04

    申请号：DEB0064151

    申请日：1961-09-27

    Applicant: BASF AG

    Inventor： NONNENMACHER DR HELMUT ,  APPL DR MAX ,  ANDRUSSOW DR KONSTANTIN ,  HAUG DR JUERGEN

    IPC: B01J23/16 ,  B01J23/22 ,  B01J23/847 ,  B01J27/198 ,  B01J27/199 ,  C07D307/89

    Abstract: Phthalic anhydride is made by treating o-xylene together with chlorine, or a chlorine compound which is vaporous under the reaction conditions, the weight ratio of chlorine, or chlorine compound, to o-xylene being from 2:100 to 1:100,000, with oxygen, or an inert gas containing free oxygen, for 5 to 50 seconds in the presence of a fluidized catalyst, at 250 to 380 DEG C., which comprises a porous carrier whose pores contain a mixture which is liquid during the reaction and which comprises vanadium pentoxide and potassium pyrosulphate or vanadium pentoxide, potassium pyrosulphate and sodium pyrosulphate with, or without, other additives; the weight ratio of vanadium pentoxide and optional additives to vanadium pentoxide being below 2:3, and the weight ratio of vanadium pentoxide to alkali metal pyrosulphate being 1:20 to 3:10. Specified carriers are aluminium phosphate, silicates, silicic acid, especially silica gel, which is preferred, and active carbon. The preferred silica gel has a grain size of 20 to 300 microns, an internal surface of 300 to 360 sq. metres per gram and a mean pore radius of 50 to 80 rA. With active carbon of grain size 20 to 600 microns the temperature should not exceed 300 DEG to 340 DEG C. Preferably, in the preparation of the catalyst, a mixture of sodium and potassium pyrosulphates, containing 10 to 50% by weight of the sodium compound is used. Vanadium compounds may be used which are convertible to the pentoxide under the reaction conditions e.g. the trichloride, tri- and tetra-oxide and sulphate. Preferably the melt contains 10 to 20% by weight of vanadium pentoxide. Activators which aid in the oxidation of hydrogen chloride to chlorine are advantageously used in quantities of up to 5% by weight of the melt. Indicated activators are compounds, especially oxides, of iron, nickel and cobalt and particularly of cerium, copper and manganese. Phosphoric acid, molybdenium trioxide and/or tungsten trioxide may also be present or formed in situ. Silver oxide may be present. Advantageously sulphur trioxide is present. The sulphur trioxide may be generated in situ e.g. from thiophene or carbon disulphide. Preferably 25 to 50% by weight of melt is used in the catalyst. The preferred temperature is 270 to 350 DEG C. A residence time of 8 to 30 seconds is preferred. Indicated chlorine compounds are hydrogen chloride, ammonium chloride, nitrosyl chloride, thionyl chloride, alkyl chlorides, aryl chlorides, aralkyl chlorides and carboxylic acid chlorides of fatty acids or of aryl mono- or dicarboxylic acids or aralkyl-carboxylic acids, preferred being o-xylyl chloride, o-xylylene dichloride or o-xylylidene dichloride. Pressures of up to 25 atmospheres may be used. Chlorine may be introduced in an inert gas e.g. nitrogen. Examples are provided. Specifications 906,311, 908,823 and 941,293 are referred to.

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