41.
    发明专利
    未知

    公开(公告)号:BRPI0417859A

    公开(公告)日:2007-04-27

    申请号:BRPI0417859

    申请日:2004-12-21

    Applicant: BASF AG

    Abstract: A process for removing trioxane from a mixture I of formaldehyde, trioxane and water, by a) distilling the mixture I in a first distillation stage at a pressure of from 0.1 to 2 bar to obtain a stream II which comprises formaldehyde and a stream III which comprises predominantly trioxane and additionally water and formaldehyde, b) mixing the stream III with a recycle stream VII which comprises predominantly trioxane and additionally water and formaldehyde to obtain a stream IIIa which comprises predominantly trioxane and additionally water and formaldehyde, c) distilling the stream IIIa, if appropriate after removing low boilers from the stream III or IIIa in a further distillation stage, in a second distillation stage at a pressure of from 0.2 to 10 bar, the pressure in the second distillation stage being at least 0.1 bar higher than the pressure in the first distillation stage, to obtain a stream IV of trioxane and a stream V which comprises predominantly trioxane and additionally water and formaldehyde, d) distilling the stream V in a third distillation stage at a pressure of from 0.1 to 4 bar to obtain a stream VI which comprises predominantly water and additionally formaldehyde, and the recycle stream VII which comprises predominantly trioxane and additionally water and formaldehyde, e) if appropriate, distilling the stream VI in a fourth distillation stage to obtain a stream VIII which comprises predominantly water, and a stream IX which comprises predominantly formaldehyde.

    42.
    发明专利
    未知

    公开(公告)号:DE102005036544A1

    公开(公告)日:2007-02-15

    申请号:DE102005036544

    申请日:2005-08-03

    Applicant: BASF AG

    Abstract: The invention relates to an integrated process for preparing trioxane from formaldehyde, comprising the steps of: a) a stream A 1 comprising water and formaldehyde and a recycle stream B 2 consisting substantially of water and formaldehyde are fed to a trioxane synthesis reactor and allowed to react to obtain a product stream A 2 comprising trioxane, water and formaldehyde; b) stream A 2 is fed to a first low-pressure distillation column and distilled at a pressure of from 0.1 to 2.5 bar to obtain a stream B 1 enriched in trioxane and additionally comprising water and formaldehyde, and the recycle stream B 2 consisting substantially of formaldehyde and water; c) stream B 1 and a recycle stream D 1 comprising trioxane, water and formaldehyde are fed to a second low-pressure distillation column and distilled at a pressure of from 0.1 to 2.5 bar to obtain a stream C 1 comprising predominantly trioxane and additionally formaldehyde and water, and a stream C 2 consisting substantially of formaldehyde and water; d) stream C 1 is fed to a high-pressure distillation column and distilled at a pressure of from 0.2 to 17.5 bar to obtain the recycle stream D 1 and a product stream D 2 consisting substantially of trioxane, in which a removal of the low boilers present in streams B 1 or C 1 may be undertaken between steps b) and c) or c) and d).

    43.
    发明专利
    未知

    公开(公告)号:DE102005027701A1

    公开(公告)日:2006-12-21

    申请号:DE102005027701

    申请日:2005-06-15

    Applicant: BASF AG

    Abstract: Processes for preparing tri- and tetraoxymethylene glycol dimethyl ether (POMDMEn=3,4) include feeding a reaction mixture of an aqueous formaldehyde solution and methanol into a reactive evaporator and separating into a first low boiler fraction and a first high boiler fraction, recycling the first high boiler fraction into the reactor, feeding the first low boiler fraction into a first distillation column and separating into a second low boiler fraction and a second high boiler fraction, recycling the second high boiler fraction into the reactive evaporator, feeding the second low boiler fraction into a second distillation column and separating into a third low boiler fraction and a third high boiler fraction, feeding the third high boiler fraction into a phase separation apparatus and separating into an aqueous phase and an organic phase, and feeding the organic phase into a third distillation column and separating into a low and high boiler fractions.

    45.
    发明专利
    未知

    公开(公告)号:DE10361518A1

    公开(公告)日:2005-07-28

    申请号:DE10361518

    申请日:2003-12-23

    Applicant: BASF AG

    Abstract: A process for removing trioxane from a mixture I of formaldehyde, trioxane and water, by a) distilling the mixture I in a first distillation stage at a pressure of from 0.1 to 2 bar to obtain a stream II which comprises formaldehyde and a stream III which comprises predominantly trioxane and additionally water and formaldehyde, b) mixing the stream III with a recycle stream VII which comprises predominantly trioxane and additionally water and formaldehyde to obtain a stream IIIa which comprises predominantly trioxane and additionally water and formaldehyde, c) distilling the stream IIIa, if appropriate after removing low boilers from the stream III or IIIa in a further distillation stage, in a second distillation stage at a pressure of from 0.2 to 10 bar, the pressure in the second distillation stage being at least 0.1 bar higher than the pressure in the first distillation stage, to obtain a stream IV of trioxane and a stream V which comprises predominantly trioxane and additionally water and formaldehyde, d) distilling the stream V in a third distillation stage at a pressure of from 0.1 to 4 bar to obtain a stream VI which comprises predominantly water and additionally formaldehyde, and the recycle stream VII which comprises predominantly trioxane and additionally water and formaldehyde, e) if appropriate, distilling the stream VI in a fourth distillation stage to obtain a stream VIII which comprises predominantly water, and a stream IX which comprises predominantly formaldehyde.

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