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US 8,802,902 B2Granted
Pressure driven distillation for ethanol production and recovery from hydrogenation process
AssigneeCelanese International Corporation
InventorsR. Jay Warner, David Lee, Adam Orosco
Life of this patent
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Abstract
Recovery of alcohols, in particular ethanol, from a crude ethanol product obtained from the hydrogenation of acetic acid using pressure driven distillation to separate the crude ethanol product. The crude ethanol product may be fed to a distillations column in which a substantial portion of the water is removed with the acetic acid in the residue. A second column is at higher pressure than a first column.
Claims18
A process for producing ethanol, comprising the steps of:
- hydrogenating acetic acid from an acetic acid feed stream in a reactor to form a crude ethanol product comprising ethanol, ethyl acetate, acetic acid, and water;
- separating at least a portion of the crude ethanol product in a first column at a first pressure into a first distillate comprising ethanol, ethyl acetate, and low concentration of water, and a first residue comprising from 2.5 to 40 wt. % acetic acid, from 60 to 99 wt. % water, and less than 0.5 wt. % ethanol, and
- separating at least a portion of the first distillate in a second column at a second pressure to yield an ethanol product stream and an ethyl acetate stream;
- wherein the second pressure is higher than the first pressure and;
- wherein the first distillate is not dehydrated using an adsorption unit or membrane.
2 more elements
A process for producing ethanol, comprising the steps of:
- hydrogenating acetic acid from an acetic acid feed stream in a reactor to form a crude ethanol product consisting of a) ethanol, b) ethyl acetate, c) acetaldehyde, d) water and e) one or more compounds selected from the group consisting of:
- 1) esters selected from the group consisting of ethyl propionate, methyl acetate, isopropyl acetate, n-propyl acetate, n-butyl acetate, and mixtures thereof,
- 2) ethers selected from the group consisting of diethyl ether, methyl ether, isobutyl ethyl ether, and mixtures thereof,
- 3) alcohols selected from the group consisting of methanol, isopropanol, n-propanol, n-butanol, 2-butanol, and mixtures thereof,
- 4) acetal, and
- 5) acetone;
- separating at least a portion of the crude ethanol product in a first column at a first pressure into a first distillate comprising ethanol, ethyl acetate, and low concentration of water, and a first residue comprising water, and
- separating at least a portion of the first distillate in a second column at a second pressure to yield an ethanol product stream and an ethyl acetate stream;
- wherein the second pressure is higher than the first pressure and;
- wherein the first distillate is not dehydrated using an adsorption unit or membrane.
7 more elements
Dependencies are inferred from the claim text.