Dilute acetic acid (AA) streams (4.5-15%, w/w) were used in an extractive esterification with 2-ethyl-1-hexanol, exploiting the different solubilities of acetic acid and acetic ester in water. The main advantage of the process is the simultaneous water purification and production of an ester having a good commercial value. The new method proposed has the purposes to save the costs arising from the treatment of the waste water and utilize in chemical synthesis the acetic acid otherwise eliminated. The performed reaction is a three-phase system which Amberlyst 15 was used as acid catalyst in. It was clearly demonstrated that the reaction takes place in the organic phase and not in the aqueous one and a conversion of about 70% can be reached. A simplified mathematical model was also proposed. (c) 2005 Elsevier B.V. All rights reserved.