Reducing acetals during ethanol separation process
AssigneeCelanese International Corporation
InventorsDavid Lee, Adam Orosco, Lincoln Sarager, R. Jay Warner, Radmila Jevtic, Victor J. Johnston
Life of this patent
Estimating the term…
Abstract
To reduce acetal concentrations when separating ethanol from a crude product in one or more distillation column, at least one of the columns is operated at a higher pressure to increase the equilibrium constant that favors hydrolysis of the acetal. The crude product may comprise ethanol, acetaldehyde, water and one or more acetals, such as diethyl acetal. The acetal concentration may be reduced thus reducing the need to separate acetal from the crude product.
Claims21
A method for producing ethanol comprising:
- hydrogenating alkanoic acid and/or esters thereof in a reactor in the presence of a catalyst to form a crude ethanol mixture comprising acetaldehyde, ethanol, water, and diethyl acetal;
- and
- separating the crude ethanol mixture in the one or more columns to recover an ethanol product comprises less than 1 wt. % diethyl acetal, wherein at least one column is operated above atmospheric pressure.
A method for producing ethanol comprising:
- hydrogenating alkanoic acid and/or esters thereof in a reactor in the presence of a catalyst to form a crude ethanol mixture;
- separating a portion of the crude ethanol mixture in a first distillation column to yield a first residue comprising alkanoic acid, and a first distillate comprising ethanol, and acetaldehyde;
- and
- separating a portion of the first distillate in a second distillation column operated above atmospheric pressure to yield a second residue comprising ethanol, and a second distillate comprising acetaldehyde,
- wherein the second residue comprises less than 1 wt. % diethyl acetal.
A method for producing ethanol comprising:
- providing a crude ethanol mixture comprising acetic acid, acetaldehyde, ethanol, water, and diethyl acetal;
- separating a portion of the crude ethanol mixture in a first distillation column to yield a first residue comprising acetic acid, and a first distillate comprising ethanol, and acetaldehyde;
- and
- separating a portion of the first distillate in a second distillation column operated above atmospheric pressure to yield a second residue comprising ethanol, and a second distillate comprising acetaldehyde,
- wherein the second residue comprises less than 1 wt. % diethyl acetal.
A method for producing ethanol comprising:
- hydrogenating alkanoic acid and/or esters thereof in a reactor in the presence of a catalyst to form a crude ethanol mixture;
- separating a portion of the crude ethanol mixture in a first distillation column to yield a first residue comprising alkanoic acid, and a first distillate comprising ethanol, water, ethyl acetate, and acetaldehyde;
- separating a portion of the first distillate in a second distillation column operated above atmospheric pressure to yield a second residue comprising ethanol and water, and a second distillate comprising ethyl acetate and acetaldehyde;
- and
- separating a portion of the second residue in a third distillation column operated to yield a third residue comprising water, and a third distillate comprising ethanol,
- wherein the third distillate comprises less than 1 wt. % diethyl acetal.
A method for producing ethanol comprising:
- providing a crude ethanol mixture comprising acetic acid, acetaldehyde, ethanol, water, and diethyl acetal;
- separating a portion of the crude ethanol mixture in a first distillation column to yield a first residue comprising acetic acid, and a first distillate comprising ethanol, water, ethyl acetate, and acetaldehyde;
- separating a portion of the first distillate in a second distillation column operated above atmospheric pressure to yield a second residue comprising ethanol and water, and a second distillate comprising ethyl acetate and acetaldehyde;
- and
- separating a portion of the second residue in a third distillation column operated to yield a third residue comprising water, and a third distillate comprising ethanol,
- wherein the third distillate comprises less than 1 wt. % diethyl acetal.
Dependencies are inferred from the claim text.