METHOD FOR DEHYDRATING ETHANOL WITH PRODUCTION OF ETHYLENE WITH LOW ENERGY CONSUMPTION Russian patent published in 2018 - IPC C07C1/24 C07C11/04 C07C29/76 

FIELD: chemistry.

SUBSTANCE: method comprises: a) a step of heating the ethanol feedstock to a temperature in the range of 100 to 130 °C due to the heat exchange with the effluent leaving stage e); b) a step of pretreating the ethanol feedstock on a solid acid at a temperature in the range of 100 to 130 °C to obtain a pretreated ethanol feedstock; c) a step of evaporating the evaporable feedstock containing the pretreated ethanol feedstock and, at least, a portion of the wastewater stream recycled from step h) in the heat exchanger by the heat exchange with the effluent from the last reactor of step e), wherein the evaporated feed is fed to the evaporation stage at a pressure in the range of 0.1 to 1.4 MPa in order to produce a vaporized feedstock; d) a step of compressing the evaporated feedstock in the compressor in order to produce a compressed feedstock; e) a step of dehydrating the compressed feedstock in, at least, one adiabatic reactor that contains, at least, one dehydration catalyst and wherein the dehydration reaction takes place at an inlet temperature in the range of 350 to 550 °C and an inlet pressure in the range of 0.3 to 1.8 MPa; f) a step of separating the effluent from the last adiabatic reactor in step e) into an effluent stream comprising ethylene at a pressure of less than 1.6 MPa and an effluent containing water; g) a step of purifying, at least, a portion of the effluent stream containing water and produced at outlet f), separating, at least, one wastewater stream and, at least, one stream of unconverted ethanol; h) a step of recirculating, at least, a portion of the wastewater stream, produced at outlet g) to inlet c).

EFFECT: use of the proposed method makes it possible to significantly reduce energy consumption in the production of ethylene.

12 cl, 1 ex, 7 tbl, 1 dwg