Patent ID: 9353074
Filing Date: 2016-05-31
CPC Classification: C07C,C07D,Y02P

Claim Text:
1. A process for the dehydration of an ethanol feed to ethylene then oxidation of the ethylene to ethylene oxide, comprising: a) an optional step for preheating said ethanol feed to a temperature in the range 70° C. to 130° C. by heat exchange with the effluent obtained from step e); b) an optional step for pre-treatment of the ethanol feed over an acidic solid operating at a temperature in the range 70° C. to 130° C. in order to produce a pre-treated ethanol feed; c) a step for vaporization of a vaporization feed comprising said optionally pre-treated ethanol feed and at least a portion of the flow of diluting water comprising ethanol recycled in accordance with step h) to an exchanger by means of an exchange of heat with the effluent obtained from the last reactor of step e), said vaporization feed being introduced into said vaporization step at a pressure in the range 0.1 to 1.4 MPa so as to produce a vaporized feed; d) a step for compressing and superheating said vaporized feed in a compressor so as to produce a compressed feed which is at the temperature for supplying to the dehydration section e); e) a step for dehydration of a mixture comprising said compressed feed and the vaporized flow of diluting water comprising the ethanol obtained from step h), said mixture having a ratio of water to ethanol in the range 1 to 4 by weight, in at least one adiabatic reactor containing at least one dehydration catalyst and in which the dehydration reaction takes place, operating at an inlet temperature in the range 350° C. to 550° C. and at an inlet pressure in the range 0.3 to 1.8 MPa; f) a step for separating the effluent obtained from the last adiabatic reactor of step e) into an effluent comprising ethylene at a pressure of less than 1.6 MPa and an effluent comprising water; g) a step for purification of at least a portion of the effluent comprising water obtained from step f) and separation into at least a flow of treated water and a flow of diluting water comprising ethanol; h) a step for recycling and vaporization of at least a portion of the flow of diluting water comprising ethanol obtained from step g) by partial or total vaporization in an exchanger using heat exchange with a quench flow obtained from oxidation step j) in a vaporization exchanger, said quench flow being cooled and then being recycled to the reactor or reactors of oxidation step j), said flow of at least partially vaporized diluting water comprising ethanol being recycled upstream of step e), the non-vaporized portion of the flow of treated water obtained from step g) being recycled to the inlet to vaporization step c); i) a step for compression of the effluent comprising ethylene obtained from step f); j) a step for oxidation of the ethylene comprised in the effluent comprising ethylene obtained from step i) into ethylene oxide, this oxidation step comprising at least one tubular oxidation reactor cooled by vaporization of said quench flow obtained from step h), said quench flow which has thus been reheated being recycled to step h).