The synthesis of ETBE (ethyl tert-butyl ether) from the reaction of ethanol with isobutene is an exothermic reaction of equilibrium. To increase the conversion of isobutene requires operating the reaction system at low temperatures and with excess ethanol in order to displace the equilibrium towards the products. ETBE and ethanol form an azeotropic mixture which hinders the recycling of nonreacted ethanol in the process. The purpose of this work is to optimize the synthesis of ETBE eliminating the introduction of water into the system to break the ETBE/Ethanol azeotrope. The production process model proposed here eliminates the recycling of ethanol and suggests the use of the azeotropic mixture (ETBE/Ethanol) in the formulation of gasolines. The direct use of the azeotrope in the formulation of automotive gasolines reduces the implementation and production costs of ETBE. (C) 2008 Elsevier B.V. All rights reserved.