2.
    发明专利
    未知

    公开(公告)号:DE50302480D1

    公开(公告)日:2006-04-27

    申请号:DE50302480

    申请日:2003-05-02

    Applicant: BASF AG

    Abstract: A process prepares an aqueous alkali metal acrylate solution by distillatively removing acrylic acid from a mixture as vapors and taking up the vapors immediately from the gas phase into an aqueous alkali solution.

    3.
    发明专利
    未知

    公开(公告)号:DE50008266D1

    公开(公告)日:2004-11-18

    申请号:DE50008266

    申请日:2000-10-31

    Applicant: BASF AG

    Abstract: In a process for the two-stage catalytic gas-phase oxidation of propene to acrylic acid, the reaction gas starting mixture is passed, in a tube-bundle reactor, with a propene loading of >=160 l (S.T.P.) of propene/l.h, first over a fixed catalyst bed 1 present in two successive temperature zones A, B and then over a fixed catalyst bed 2 which is housed either in one further temperature zone C or in two further temperature zones D, E, the temperature of the zone A being kept at a lower temperature than the zone B and the temperature of the zone D at a lower temperature than the zone E.

    5.
    发明专利
    未知

    公开(公告)号:DE50108001D1

    公开(公告)日:2005-12-15

    申请号:DE50108001

    申请日:2001-04-04

    Applicant: BASF AG

    Abstract: In a process for the purification of a crude acrylic acid melt, the crude acrylic acid melt is converted, under the action of low temperatures, into a crude acrylic acid suspension consisting of acrylic acid crystals and residual melt, and the acrylic acid crystals of the crude acrylic acid suspension are freed from remaining residual melt in a wash column, the production of the acrylic acid crystals of the crude acrylic acid suspension being carried out in the presence of water, the wash column being a wash column with forced transport of the acrylic acid crystals and the wash liquid used being the melt of acrylic acid crystals purified in the wash column.

    6.
    发明专利
    未知

    公开(公告)号:DE59706057D1

    公开(公告)日:2002-02-21

    申请号:DE59706057

    申请日:1997-07-09

    Applicant: BASF AG

    Abstract: A process for preparing acrylic acid or methacrylic acid comprises(a) preparing a gaseous product mixture having essentially the composition of a reaction mixture of the catalytic gas phase oxidation of C3-/C4-alkanes, -alkenes, -alkanols and/or -alkanals and/or precursors thereof to form acrylic acid or methacrylic acid, characterized by(b) condensing said product mixture,(c) crystallizing acrylic acid or methacrylic acid from the solution obtained in step (b), and(d) removing the resulting crystals from the mother liquor.

    9.
    发明专利
    未知

    公开(公告)号:DE59702539D1

    公开(公告)日:2000-11-30

    申请号:DE59702539

    申请日:1997-06-24

    Applicant: BASF AG

    Abstract: PCT No. PCT/EP97/03304 Sec. 371 Date Dec. 30, 1998 Sec. 102(e) Date Dec. 30, 1998 PCT Filed Jun. 24, 1997 PCT Pub. No. WO98/01414 PCT Pub. Date Jan. 15, 19981,4-Dibenzothiazine-comprising crude acrylic acid is purified by crystallization by raising its diacrylic acid content to at least 1% by weight prior to the crystallization step.

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