Processes for increasing alcohol production
AssigneeCelanese International Corporation
InventorsAdam Orosco, Manuel Salado, Lincoln Sarager, R. Jay Warner, Trinity Horton
Life of this patent
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Abstract
A process for reducing ethyl acetate and/or diethyl acetal concentration of a crude ethanol product by hydrolysis is disclosed. A portion of the water is initially separated from the crude ethanol product in a first column residue. Ethyl acetate in the first column distillate is hydrolyzed to form additional ethanol and acetic acid. Product ethanol is recovered in a second distillation column preferably in a side stream and acetic acid is removed in the second column residue.
Claims29
A process for producing ethanol, the process comprising the steps of:
- (a) hydrogenating acetic acid in a reactor in the presence of a catalyst to form a crude ethanol product;
- (b) separating at least a portion of the crude ethanol product in a first distillation column to yield a first distillate comprising ethanol, at least 0.1 wt. % water, and ethyl acetate and a first residue comprising acetic acid;
- (c) hydrolyzing a portion of the ethyl acetate in the first distillate to form ethanol and acetic acid;
- and
- (d) separating at least a portion of the hydrolyzed first distillate in a second distillation column to yield a second distillate comprising ethyl acetate and a side stream comprising from 10 wt. % to 99.5 wt. % ethanol, less than 1.0 wt. % ethyl acetate, and less than 1.0 wt. % acetic acid, and a second residue comprising acetic acid;
- wherein the first distillate, prior to hydrolysis, has a water to ethyl acetate molar ratio of greater than 3:1.
A process for producing ethanol, the process comprising the steps of:
- (a) hydrogenating acetic acid in a reactor in the presence of a catalyst to form a crude ethanol product;
- (b) separating at least a portion of the crude ethanol product in a first distillation column to yield a first distillate comprising ethanol, at least 0.1 wt. % water, and ethyl acetate and a first residue comprising acetic acid;
- (c) hydrolyzing at least a portion of the ethyl acetate under conditions effective to form additional ethanol and additional acetic acid;
- and
- (d) separating at least a portion of the first distillate in a second distillation column to yield a side stream comprising from 10 wt. % to 99.5 wt. % ethanol, less than 1.0 wt. % ethyl acetate, and less than 1.0 wt. % acetic acid, and a second residue comprising acetic acid, wherein the second residue is returned to the reactor in step (a);
- and wherein the first distillate, prior to hydrolysis, has a water to ethyl acetate molar ratio of greater than 3:1.
A process for producing ethanol, the process comprising the steps of:
- (a) hydrogenating acetic acid in a reactor in the presence of a catalyst to form a crude ethanol product;
- (b) separating at least a portion of the crude ethanol product in a first distillation column to yield a first distillate comprising ethanol, at least 0.1 wt. % water, ethyl acetate and a minor amount of acetic acid and a first residue comprising acetic acid;
- (c) increasing the amount of ethanol and the amount of acetic acid in the first distillate;
- and
- (d) separating at least a portion of the first distillate in a second distillation column to yield a second distillate comprising ethyl acetate and a side stream comprising from 10 wt. % to 99.5 wt. % ethanol, less than 1.0 wt. % ethyl acetate, and less than 1.0 wt. % acetic acid, and a second residue comprising acetic acid;
- and wherein the first distillate in step (b) has a water to ethyl acetate molar ratio of greater than 3:1.
Dependencies are inferred from the claim text.