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).