Referring now to the drawing, crude aldehyde from a decobalting unit (not sho-wn), which may contain about 30%-50% aldehyde, 5%-20% alcohol, the balance being other impurities such as esters and acetals, is passed through line 2 to water separator Li, where, by settling or other conventional means, a substantially dry product is produced. it is to be understood that the aldehydes may be derived fr