Method for removing formic acid from aqueous solutions

    公开(公告)号:AU2002319208A1

    公开(公告)日:2002-12-23

    申请号:AU2002319208

    申请日:2002-06-10

    Applicant: BASF AG

    Inventor: NOBEL THOMAS

    Abstract: Formic acid is at least partly removed from an aqueous solution comprising formic acid, cyclohexanone and cyclohexanol by decomposition over certain decomposition catalysts. The method is preferably used for processing reaction products from the oxidation of cyclohexane and comprises: (i) extracting a product gas mixture obtained in the oxidation of cyclohexane with an aqueous scrubbing liquid, (ii) separating the aqueous solution obtained in (i) by distillation into an aqueous solution comprising formic acid, cyclohexanone and cyclohexanol together with further minor organic components and a carboxylic acid mixture (iii) removing the formic acid at least partially from the aqueous solution obtained in (ii) by decomposition, and (iv) further processing the aqueous solution obtained in (iii) to give epsilon-caprolactam, or using the aqueous solution obtained in (iii) as scrubbing liquid in (i).

    4.
    发明专利
    未知

    公开(公告)号:ES2218186T3

    公开(公告)日:2004-11-16

    申请号:ES00949204

    申请日:2000-06-21

    Applicant: BASF AG

    Abstract: A process for preparing 1,6-hexanediol from a carboxylic acid mixture comprising adipic acid, 6-hydroxycaproic acid and small amounts of 1,4-cyclohexanediols which is obtained as by-product in the oxidation of cyclohexane to cyclohexanone/cyclohexanol after water extraction of the reaction mixture followed by extraction with aqueous sodium hydroxide solution, by esterification of the acids and hydrogenation comprisesa) liberating the carboxylic acids from the alkaline extract by addition of a mineral acid,b) fractionating the organic phase comprising carboxylic acids to give a distillate comprising the low molecular weight monocarboxylic acids and a residue comprising adipic acid and 6-hydroxycaproic acid,c) reacting the monocarboxylic an dicarboxylic acids present in the aqueous dicarboxylic acid mixture with a low molecular weight alcohol to give the corresponding carboxylic esters,d) freeing the esterification mixture obtained of excess alcohol and low boilers in a first distillation step,e) fractionating the bottom product in a second distillation step to give an ester fraction essentially free of 1,4-cyclohexanediols and a fraction comprising at least the major part of the 1,4-cyclohexanediols,f) catalytically hydrogenating the ester fraction which is essentially free of 1,4-cyclohexanediols andg) isolating 1,6-hexanediol from the hydrogenation product in a manner known per se in a final distillation step.

    Method for producing hexanediol
    7.
    发明专利

    公开(公告)号:AU6264600A

    公开(公告)日:2001-01-22

    申请号:AU6264600

    申请日:2000-06-21

    Applicant: BASF AG

    Abstract: A process for preparing 1,6-hexanediol from a carboxylic acid mixture comprising adipic acid, 6-hydroxycaproic acid and small amounts of 1,4-cyclohexanediols which is obtained as by-product in the oxidation of cyclohexane to cyclohexanone/cyclohexanol after water extraction of the reaction mixture followed by extraction with aqueous sodium hydroxide solution, by esterification of the acids and hydrogenation comprisesa) liberating the carboxylic acids from the alkaline extract by addition of a mineral acid,b) fractionating the organic phase comprising carboxylic acids to give a distillate comprising the low molecular weight monocarboxylic acids and a residue comprising adipic acid and 6-hydroxycaproic acid,c) reacting the monocarboxylic an dicarboxylic acids present in the aqueous dicarboxylic acid mixture with a low molecular weight alcohol to give the corresponding carboxylic esters,d) freeing the esterification mixture obtained of excess alcohol and low boilers in a first distillation step,e) fractionating the bottom product in a second distillation step to give an ester fraction essentially free of 1,4-cyclohexanediols and a fraction comprising at least the major part of the 1,4-cyclohexanediols,f) catalytically hydrogenating the ester fraction which is essentially free of 1,4-cyclohexanediols andg) isolating 1,6-hexanediol from the hydrogenation product in a manner known per se in a final distillation step.

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