Process for the production of ethanol by hydrogenation of methyl acetate

Abstract

Process for the production of ethanol from acetic acid and hydrogen, said process comprising: reacting in an esterification reaction vessel methanol with acetic acid in the presence of an esterification catalyst and an entrainer to form a product comprising entrainer, methyl acetate and water, and in a distillation column, recovering from the product an overhead product fraction comprising methyl acetate, methanol and water, feeding the overhead product fraction, together with hydrogen, into a hydrogenation unit containing a copper based hydrogenation catalyst, to produce a hydrogenation product stream comprising ethanol, methanol, unreacted methyl acetate, unreacted hydrogen, ethyl acetate and water, cooling the hydrogenation product stream; separating the cooled hydrogenation product stream into a liquid phase which comprises the majority of the methanol, ethanol, methyl acetate, ethyl acetate and water, and a gaseous phase which comprises the majority of the unreacted hydrogen; recycling at least part of the gaseous phase to the hydrogenation unit; separating a lower boiling product stream comprising methanol, methyl acetate and ethyl acetate, and a higher boiling product stream comprising ethanol, water, from the liquid phase; recycling at least part of the lower boiling product stream to the esterification reaction vessel; and, optionally removing water from the higher boiling product stream.