LOW-ENERGY CONSUMPTION METHOD FOR DEHYDRATING ETHANOL INTO ETHYLENE

摘要

The invention describes a method for dehydrating an ethanol load into ethylene, comprising the vaporisation of said ethanol load in a mixture with at least one part of the flow of purified water recycled according to step f) in an exchanger, as a result of an exchange of heat with the effluent from the last reactor, said mixture being introduced into said vaporisation step at a pressure of between 0.1 and 0.4 MPa, the compression of the vaporised mixture in a compressor, the introduction of the vaporised and compressed mixture, at an inlet temperature of between 350 and 500°C and at an inlet pressure of between 0.2 and 1.3 MPa, into at least one adiabatic reactor containing at least one dehydration catalyst and in which the dehydration reaction takes place, the separation of the effluent from the last adiabatic reactor from step c) into an effluent comprising ethylene at a pressure lower than 1 MPa and an effluent comprising water, the purification of at least one part of the effluent comprising water from step d) and the separation of at least one flow of purified water and at least one flow of unconverted ethanol, the recycling of at least one part of the flow of purified water from step e) upstream from step a).