PROBLEM TO BE SOLVED: To increase the purification efficiency by previously adding an amine bearing an electron donative substituent to a distillation column, when aldehyde contaminants are removed in the chemical production process. ;SOLUTION: (A) A solution of a substituted aromatic amine bearing an electroron donative substituent is prepared by using a solvent including a catalyst amount of mineral acid, (B) the resultant solution prepared in (A) is added to the liquid flow contaminated with aldehyde at the inlet of the distillation column in an effective amount for aldehyde removal (C) to form an aldehyde- aromatic amine Schiff base whereby the aldehyde is removed (this base is to remain the distillation column), then (D) the purified flow is recovered from the outlet end of the purification column whereby the aldehyde is removed from the flow passing through the distillation column having the inlet edge and the outlet edge. This process is particularly advantageous for removal of acrolein and 2-aminoaniline, 3,4-dimethylaniline, 4-ethylaniline can be cited as the above-cited aromatic amine.;COPYRIGHT: (C)2000,JPO
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