Catalyst for maleic anhydride prodn. - from 4c unsatd. linear hydrocarbons

    公开(公告)号:DE1949491A1

    公开(公告)日:1971-04-08

    申请号:DE1949491

    申请日:1969-10-01

    Applicant: BASF AG

    Abstract: The process involves (1) Adding a mixture of C4 hydrocarbons (I) of which >=50% are linear and olefinically unsatd. to air, heated to 100-200 degrees C. (2) Adding a volatile organic or mineral phosphorus cpd (II). (3) Passing the mixture through a tubular reactor at 420-600 degrees C lined with catalyst contg. 45-95% TiO2, 0.2-20% V2O5 and 3-53% P2Ok. (4) HEat exchange being carried out by a circulated salt bath at 350-440 degrees C supplied at one end of the reactor at constant flow through an annular tube and discharging from the other end of the reactor through a second annular tube. (5) Cooling the reacted mixture to 160-180 degrees C and washing it to extract maleic anhydride using cold aqs. maleic acid soln. which is obtained at concn. 30-50%. (6) Evaporating the soln. to >90% conc. in thin film evaporators. (7) Splitting maleic anhydride and water vapour in another evaporator. (8) Refining the crude product by continuous fractionation. (I) may contain 0-30% butadiene, 20-100% n-butenes, 0-50% isobutene and 10-50% butanes where the total of butadiene and n-butenes is >=50%. (II) is a trialkyl 1-4C phosphate. Content of (I) is 25-40g/m3 normal of the heated air. The process uses cheaper raw materials, than known maleic anhydride production precesses, and is simpler to control, more trouble free, and gives improved yields of high quality product.

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