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US 8,575,404 B2Granted
Process for recycling gas from acetic acid hydrogenation
AssigneeCelanese International Corporation
InventorsRadmila Jevtic, Victor J. Johnston, R. Jay Warner, John Potts, Stephen Kerlegon
Life of this patent
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Abstract
Monitoring and recycling gases from acetic acid hydrogenation reaction to maintain a constant pressure in the hydrogenation reaction system. Purging of the vapor stream comprising hydrogen may be limited or reduced. Further purging of the by-product may be from the dissolved by-product gases.
Claims27
A process for producing ethanol comprising the steps of:
- hydrogenating acetic acid from an acetic acid feed stream in a reactor in the presence of a catalyst to form a crude ethanol product comprising ethanol;
- separating at least a portion of the crude ethanol product to yield a vapor stream and a liquid stream, wherein the vapor stream comprises unreacted hydrogen and at least one by-product gas, and wherein the liquid stream comprises ethanol and at least one dissolved by-product gas;
- purging less than 15% of the vapor stream in a first purge stream;
- purging at least a portion of at least one dissolved by-product gas from the liquid stream to form a second purge stream;
- returning at least a portion of the vapor stream directly or indirectly to the reactor;
- and
- recovering ethanol from the liquid stream.
4 more elements
A process for producing ethanol comprising the steps of:
- hydrogenating acetic acid from an acetic acid feed stream in a reactor in the presence of a catalyst to form a crude ethanol product comprising ethanol;
- separating at least a portion of the crude ethanol product to yield a vapor stream and a liquid stream, wherein the vapor stream comprises unreacted hydrogen and carbon monoxide in an amount from 0.01 to 2 mol. %, and wherein the liquid stream comprises ethanol and at least one dissolved by-product gas;
- purging at least a portion of at least one dissolved by-product gas from the liquid stream to form a second purge stream;
- returning at least a portion of the vapor stream directly or indirectly to the reactor;
- and
- recovering ethanol from the liquid stream.
3 more elements
A process for producing ethanol comprising the steps of:
- hydrogenating acetic acid from an acetic acid feed stream and a hydrogen feed stream in a reactor system in the presence of a catalyst to form a crude ethanol product comprising ethanol;
- separating at least a portion of the crude ethanol product to yield a vapor stream and a liquid stream, wherein the vapor stream comprises unreacted hydrogen, and wherein the liquid stream comprises ethanol;
- returning at least a portion of the vapor stream directly or indirectly to the reactor;
- measuring a pressure of the vapor stream or a pressure of the at least a portion of the vapor stream;
- controlling pressure in the reactor system by regulating the feed of fresh hydrogen to the reactor in response to the measured pressure;
- and
- recovering ethanol from the liquid stream.
4 more elements
A process for producing ethanol comprising the steps of:
- hydrogenating acetic acid from an acetic acid feed stream in a reactor in the presence of a catalyst to form a crude ethanol product comprising ethanol;
- separating the crude ethanol product to yield a vapor stream and a liquid stream, wherein the vapor stream comprises unreacted hydrogen and at least one by-product gas, and wherein the liquid stream comprises ethanol;
- withdrawing a slip stream from the vapor stream;
- purging a portion of the slip stream when the concentration of one of the at least one by-product gases is greater than 5 mol. %;
- and
- recovering ethanol from the liquid stream.
3 more elements
A process for producing ethanol comprising the steps of:
- hydrogenating acetic acid from an acetic acid feed stream in a reactor in the presence of a catalyst to form a crude ethanol product comprising ethanol;
- separating at least a portion of the crude ethanol product to yield a vapor stream and a liquid stream, wherein the vapor stream comprises unreacted hydrogen and at least one by-product gas, and wherein the liquid stream comprises ethanol and at least one dissolved by-product gas;
- purging the at least one dissolved by-product gas from the liquid stream;
- and
- recovering ethanol from the liquid stream.
2 more elements
Dependencies are inferred from the claim text.