The invention relates to a method for dehydrating an ethanol feedstock into ethylene, comprising: (a) a step of preheating said ethanol feedstock via heat exchange with the effluent from step (e), (b) a step of pretreating the ethanol feedstock in order to obtain a pretreated ethanol feedstock, (c) a step of vaporising, in an exchanger, a vaporisation feedstock comprising said pretreated ethanol feedstock and at least a portion of the treated water stream recycled in step (h), in order to obtain a vaporised feedstock, (d) a step of compressing said vaporised feedstock in order to obtain a compressed feedstock, (e) a step of dehydrating said compressed feedstock in at least one adiabatic reactor, (f) a step of separating the effluent from the last adiabatic reactor of step (e) into an ethylene-containing effluent and a water-containing effluent, (g) a step of purifying at least a portion of the water-containing effluent from step (f) and separating at least one treated water stream and at least one non-converted ethanol stream, (h) a step of recycling at least a portion of the treated water stream from step (g) upstream of step (c).