Method for separating trioxane from a mixture containing trioxane, formaldehyde and water

    公开(公告)号:AU2004308627A1

    公开(公告)日:2005-07-14

    申请号:AU2004308627

    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.

    4.
    发明专利
    未知

    公开(公告)号:DE10309289A1

    公开(公告)日:2004-09-16

    申请号:DE10309289

    申请日:2003-03-04

    Applicant: BASF AG

    Abstract: Process for preparing high-concentration formaldehyde solutions having a CH 2 O content of >=50% by weight from an aqueous formaldehyde solution having a lower CH 2 O content by evaporation of part of this solution (partial evaporation), in which the aqueous formaldehyde solution is heated to an evaporation temperature T at which the gas phase becomes enriched in water relative to the liquid phase and the gas phase formed is taken off continuously or discontinuously, wherein the evaporation temperature T obeys the relationship: T[° C.] max [° C.] where T max (c)=A+Bx(c/100)+Cx(c/100) 2 +Dx(c/100) 3 and A=+68.759, B=+124.77, C=-12.851, D=-10.095, where c is the instantaneous CH 2 O content of the aqueous formaldehyde solution during the evaporation in percent by weight and is from 20 to 99% by weight.

    6.
    发明专利
    未知

    公开(公告)号:NO20062749L

    公开(公告)日:2006-07-12

    申请号:NO20062749

    申请日:2006-06-13

    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.

    METHOD FOR SEPARATING TRIOXANE FROM A MIXTURE CONTAINING TRIOXANE, FORMALDEHYDE AND WATER

    公开(公告)号:CA2548640A1

    公开(公告)日:2005-07-14

    申请号:CA2548640

    申请日:2004-12-21

    Applicant: BASF AG

    Abstract: The invention relates to a method for separating trioxane from a mixture containing formaldehyde, trioxane and water. According to said method: the mixture (1) is distilled in a first distillation stage (7) at a pressure of between 0.1 and 2 bar to obtain a stream (8) containing formaldehyde and a stream (9) containing predominantly trioxane, in addition to water and formaldehyde; the stream (9) is mixed with a recycling stream (19) containin g predominantly trioxane, in addition to water and formaldehyde to form a stre am (10) containing predominantly trioxane, in addition to water and formaldehyd e; the stream (10) is then distilled in a second distillation stage (14) at a pressure of between 0.2 and 10 bar, optionally after the separation of low- boilers from the stream (9) or (10) in an additional distillation stage (11) . The pressure in the second distillation stage (14) is at least 0.1 bar highe r than the pressure in the first distillation stage (7). Said distillation produces a stream (15) consisting of trioxane and a stream (16) containing predominantly trioxane, in addition to water and formaldehyde. The stream (1 6) is then distilled in a third distillation stage (17) at a pressure of betwee n 0.1 and 4 bar, to obtain a stream (18) containing predominantly water, in addition to formaldehyde and the recycling stream (19) containing predominantly trioxane, in addition to water and formaldehyde. The resultant stream (18) is optionally distilled in a fourth distillation stage (20), to obtain a stream (21) containing predominantly water and a stream (22) containing predominantly formaldehyde.

    8.
    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.

    9.
    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.

    10.
    发明专利
    未知

    公开(公告)号:DE10309288A1

    公开(公告)日:2004-09-16

    申请号:DE10309288

    申请日:2003-03-04

    Applicant: BASF AG

    Abstract: Process for preparing high-concentration gaseous formaldehyde having a molar CH 2 O:H 2 O ratio of >=0.6 from an aqueous formaldehyde solution by evaporation of at least part of the solution, in which the aqueous formaldehyde solution is heated to a vaporization temperature T and the gas phase formed is taken off, wherein the evaporation temperature T obeys the relationship: T[° C.]>=T' min [° C.] where T' min (c)=A+Bx(c/100)+Cx(c/100) 2 +Dx(c/100) 3 and A=+68.759, B=+124.77, C=-12.851, D=-10.095, where c is the instantaneous CH 2 O content of the aqueous formaldehyde solution during the evaporation in percent by weight and is from 20 to 99% by weight.

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