Process for dehydrating and isomerizing a feedstock comprising from 40 to 100% by weight of primary alcohol substituted in position 2 by an alkyl group comprising at least the following steps: a) Pressurizing said feedstock then preheating the compressed feedstock by heat exchange with the dehydration effluent obtained from step c) in a heat exchanger to produce a preheated feedstock; b) Vaporizing said preheated feedstock by mixing with the diluent effluent obtained from step f), the ratio of the diluent effluent mass flow rate to the preheated feedstock mass flow rate being comprised between 5/95 and 60/40; c) Dehydrating the effluent obtained from step b) in at least one dehydration reactor operating in gas phase at a weighted average temperature comprised between 250 and 375°C, at a pressure comprised between 0.2 MPa and 1 MPa and at a WHSV comprised between 1 and 18 h -1, in the presence of a catalyst comprising a zeolite of FER structural type, said catalyst being coked beforehand in-situ or ex-situ, to produce a dehydration effluent; d) Cooling said dehydration effluent by at least three successive heat exchanges with at least the water effluent obtained from step e), then said compressed feedstock from step a), then a cold utility to produce a cooled effluent; e) Settling of said cooled effluent into an aqueous phase and an organic phase, a part of said aqueous phase being purged to be treated outside of said dehydration process, and the other part forming the water effluent being recycled via step f); f) Recycling the water effluent obtained from step e) and at least partial vaporization by heat exchange in a heat exchanger with the dehydration effluent obtained from step c), separation of any liquid fraction that may be present, then compression and superheating of the vapour fraction to form a diluent effluent, said diluent effluent being recycled to step b); g) Separation of the organic phase extracted from step e) in at least one distillation column to produce an alkenes effluent and a heavy hydrocarbons effluent. a) Pressurizing said feedstock then preheating the compressed feedstock by heat exchange with the dehydration effluent obtained from step c) in a heat exchanger to produce a preheated feedstock; b) Vaporizing said preheated feedstock by mixing with the diluent effluent obtained from step f), the ratio of the diluent effluent mass flow rate to the preheated feedstock mass flow rate being comprised between 5/95 and 60/40; c) Dehydrating the effluent obtained from step b) in at least one dehydration reactor operating in gas phase at a weighted average temperature comprised between 250 and 375°C, at a pressure comprised between 0.2 MPa and 1 MPa and at a WHSV comprised between 1 and 18 h -1, in the presence of a catalyst comprising a zeolite of FER structural type, said catalyst being coked beforehand in-situ or ex-situ, to produce a dehydration effluent; d) Cooling said dehydration effluent by at least three successive heat exchanges with at least the water effluent obtained from step e), then said compressed feedstock from step a), then a cold utility to produce a cooled effluent; e) Settling of said cooled effluent into an aqueous phase and an organic phase, a part of said aqueous phase being purged to be treated outside of said dehydration process, and the other part forming the water effluent being recycled via step f); f) Recycling the water effluent obtained from step e) and at least partial vaporization by heat exchange in a heat exchanger with the dehydration effluent obtained from step c), separation of any liquid fraction that may be present, then compression and superheating of the vapour fraction to form a diluent effluent, said diluent effluent being recycled to step b); g) Separation of the organic phase extracted from step e) in at least one distillation column to produce an alkenes effluent and a heavy hydrocarbons effluent.