2.
    发明专利
    未知

    公开(公告)号:BRPI0406992A

    公开(公告)日:2006-01-10

    申请号:BRPI0406992

    申请日:2004-03-20

    Applicant: BASF AG

    Abstract: A process for the heterogeneously catalyzed partial gas phase oxidation of propene to acrylic acid by passage of a gas phase mixture comprising 6-15 vol.% propene, 4-20 vol. % water and no greater than 10 vol. % of other components as well as molecular oxygen such that the molar ratio of oxygen to propene is 1.5-2.5 and the residual amount to 100 vol.% comprises molecular nitrogen though a first reaction stage. A process for the heterogeneously catalyzed partial gas phase oxidation of propene to acrylic acid by passage of a gas phase mixture (I) comprising propene, molecular oxygen and at least one inert gas having a molar ratio of oxygen to propene of at least 1. The process involves a first reaction stage at elevated temperature having a fixed catalyst bed of ring shaped catalyst having a multimetal oxide active material of formula (1). The catalyst has a volume specific activity in the flow direction of the mixture (I) which is either constant or at least increases once and the active mass composition does not change over the bed packing such that the conversion of propene is at last 90 mol.% in a single pass with a selectivity to acrolein and acrylic acid of at least 90 mol.% with direct or indirect cooling of the product mixture leaving the first reaction stage. Optional addition of molecular oxygen and/or inert gas and the product mixture comprising acrolein, molecular oxygen and at least one inert gas having a molar ratio of oxygen to acrolein of at least 0.5 is passed through a second reaction stage comprising a second fixed bed catalyst packing comprising ring shaped packing whose active mass comprises a multimetal oxide of formula (2). Multimetal oxide (2) whose volume specific activity in the direction of flow at least increases once and whose composition does not alter over the second reaction stage such that the single-pass conversion of acrolein is at least 90 mol.% and the selectivity of both reaction stages to the formation of acrylic acid (with respect to reacted propene) is at least 80 mol.% is characterized in that the reaction mixture (I) comprises 6-15 vol.% propene, 4-20 vol.% water and no greater than 10 vol. % of other components that are not propene, water, oxygen or nitrogen, as well as molecular oxygen such that the molar ratio of oxygen to propene is 1.5-2.5 and the residual amount to 100 vol.% comprises molecular nitrogen. Mo12X1aX2bX3cX4dX5eOn (1) Mo12VfX6gX7hOm (2) X1 = Bi, Co or Ni; X2 = W or Nb; X3 = Fe or Cr; X4 = K, Cs or Sr; X5 = Si, Al or Zr; X6 = W or Nb; X7 = Sb, Cu, Ni or Fe; a = 5-10; b = 0-4; c = 2-5; d = 0.02-0.15; e = 0.5-4; f = 1-5; g = 1-2; h = 1-4; m, n = number of O atoms dependent upon the valency and number of elements.

    3.
    发明专利
    未知

    公开(公告)号:BR0211582A

    公开(公告)日:2004-07-13

    申请号:BR0211582

    申请日:2002-08-02

    Applicant: BASF AG

    Abstract: Process for preparation of a water absorbing resin from acrylic acid by its absorption from the reaction gases from catalytic gas phase oxidation of propane, propylene and/or acrolein in an absorption liquid or by separation of the crude acid from the reaction gases by fractional condensation, purification by crystallization, treatment of the crude acrylic acid with an aldehyde trap, (c) separation of pure acrylic acid by distillation, and its radical polymerization is new. A process for preparation of a water absorbing resin involving:(a) production of crude acrylic acid either (a) absorption of acrylic acid from the reaction gases from the catalytic gas phase oxidation of propane, propylene and/or acrolein in an absorption liquid and isolation of crude acrylic acid from acrylic acid loaded absorption liquid, or (a2) by separation of crude acrylic acid from the reaction gases by fractional condensation, and purification by crystallization, (b) treatment of the crude acrylic acid with an aldehyde trap, (c) separation of pure acrylic acid from the crude acrylic acid by distillation, and (d) radical polymerization, optionally after partial neutralization, optionally mixed with other ethylenically unsaturated monomers, of the pure acrylic acid.

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