Method for distilling ethyl alcohol by adding salt or salts
AssigneeTsukishima Kikai Co., Ltd.
InventorMinoru Morita
Life of this patent
Estimating the term…
Abstract
A mash column (2) and a rectifying column (4) are used in combination, and impurities contained in mash feed (8) is removed out of the mash column. A salt or salts are added to the top of the rectifying column (4). Alcohol supplied from the mash column (2) is subjected to rectification in the rectifying column (4), and ethyl alcohol is obtained from the top of the rectifying column (4). Bottom products from the rectifying column (4) is concentrated by an evaporator (6) and the concentrated salt or salts solution is recycled to the rectifying column (4). Vapor generated by the evaporator (6) is used as a heat source for the mash column (2).
Claims11
A method for recovering substantially pure ethyl alcohol from a liquid, fermentation mash feed containing ethyl alcohol, comprising the steps of:
- (a) feeding the liquid fermentation mash feed into a steam-heated mash column so that said feed flows downwardly in said mash column and simultaneously flowing steam directly upwardly through said mash column in contact with said feed to remove the ethyl alcohol from said feed, discharging from the top of the mash column an overhead fraction consisting essentially of ethyl alcohol and water, and discharging from the bottom of the mash column less volatile impurities initially present in said feed which would otherwise hinder recovery of a regenerated salt solution usable in the following step (b);
- (b) feeding said overhead fraction into a rectifying column, simultaneously feeding into said rectifying column near the top thereof one or more salts effective to improve the vapor-liquid equilibrium and to cause the ethyl alcohol-water azeotrope to disappear, discharging substantially pure alcohol vapor from near the top of said rectifying column, condensing said vapor to obtain liquid ethyl alcohol and feeding a portion of said liquid ethyl alcohol to the top of the column as reflux, recovering from the bottom of the rectifying column a bottom component consisting essentially of water and said salt or salts;
- (c) evaporating water from said bottom component to obtain separately (1) steam and (2) a regenerated, concentrated salt solution;
- (d) recycling said regenerated salt solution for use in step (b);
- and
- (e) using the steam produced in step (c) as a part of the steam used for direct heat exchange in step (a).
Dependencies are inferred from the claim text.