Patents by Inventor Yaw-Hwa Liu

Yaw-Hwa Liu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9382186
    Abstract: A process for producing acetic acid is disclosed in which the water concentration is controlled in the side stream between two columns. Controlling the water concentration by the liquid light phase recycle controls the hydrogen iodide concentration in the side stream to be less than or equal to 50 wppm.
    Type: Grant
    Filed: October 2, 2015
    Date of Patent: July 5, 2016
    Assignee: CELANESE INTERNATIONAL CORPORATION
    Inventors: Ronald D. Shaver, Yaw-Hwa Liu, Mark O. Scates
  • Patent number: 9382183
    Abstract: A process for producing acetic acid is disclosed in which the methyl iodide concentration is maintained in the vapor product stream formed in a flashing step. The methyl iodide concentration in the vapor product stream ranges from 24 to less than 36 wt. %, based on the weight of the vapor product stream. In addition, the acetaldehyde concentration is maintained within the range from 0.005 to 1 wt. % in the vapor product stream. The vapor product stream is distilled in a first column to obtain an acetic acid product stream comprising acetic acid and hydrogen iodide in an amount of less than or equal to 300 wppm and/or methyl iodide in an amount from 0.1 to 6 wt. %, and an overhead stream comprising methyl iodide, water and methyl acetate.
    Type: Grant
    Filed: October 2, 2015
    Date of Patent: July 5, 2016
    Assignee: CELANESE INTERNATIONAL CORPORATION
    Inventors: Ronald D. Shaver, Yaw-Hwa Liu, Mark O. Scates
  • Publication number: 20160168068
    Abstract: Process for producing acetic acid is disclosed in which a lithium compound is added to the reaction medium to maintain a concentration of lithium acetate from 0.3 to 0.7 wt. %. The concentration of the rhodium catalyst is maintained from 300 to 3000 wppm in the reaction medium, the concentration of water is maintained from 0.1 to 4.1 wt. % in the reaction medium, and the concentration of methyl acetate is maintained from 0.6 to 4.1 wt. % in the reaction medium.
    Type: Application
    Filed: February 24, 2016
    Publication date: June 16, 2016
    Inventors: Mark O. SCATES, Yaw-Hwa LIU
  • Publication number: 20160159721
    Abstract: A process for producing an acetic acid product having low butyl acetate content via a carbonylation reaction. The carbonylation reaction is carried out at a temperature from 100 to 300° C., a hydrogen partial pressure from 0.3 to 2 atm, and a metal catalyst concentration from 100 to 3000 wppm, based on the weight of the reaction medium. The butyl acetate concentration in the acetic acid product may be controlled by removing acetaldehyde from a stream derived from the reaction medium and/or by adjusting at least one of reaction temperature, hydrogen partial pressure, and metal catalyst concentration.
    Type: Application
    Filed: February 12, 2016
    Publication date: June 9, 2016
    Inventors: Yaw-Hwa LIU, Mark O. Scates
  • Patent number: 9346734
    Abstract: The invention relates to processes for removing aromatics from the reactants that are fed to a carbonylation reactor. The aromatics are removed using a guard bed that comprises an adsorbent.
    Type: Grant
    Filed: February 3, 2015
    Date of Patent: May 24, 2016
    Assignee: CELANESE INTERNATIONAL CORPORATION
    Inventors: G. Paull Torrence, Ronald David Shaver, Yaw-Hwa Liu
  • Publication number: 20160137576
    Abstract: A process for producing an acetic acid product having low butyl acetate content via a carbonylation reaction. The carbonylation reaction is carried out at a temperature from 100 to 300° C., a hydrogen partial pressure from 0.3 to 2 atm, and a rhodium catalyst concentration from 100 to 3000 wppm, based on the weight of the reaction medium. The butyl acetate concentration in the acetic acid product may be controlled by removing acetaldehyde from a stream derived from the reaction medium and/or by adjusting at least one of reaction temperature, hydrogen partial pressure, and metal catalyst concentration.
    Type: Application
    Filed: October 2, 2015
    Publication date: May 19, 2016
    Inventors: Yaw-Hwa Liu, Mark O. Scates
  • Publication number: 20160137575
    Abstract: A process for producing high purity acetic acid from a carbonylation reaction, wherein the carbonylation reaction is carried out while maintaining a low ethyl iodide content in the reaction medium. The ethyl iodide concentration may be maintained by removing acetaldehyde from the reaction medium and/or by adjusting at least one A) hydrogen partial pressure in the reactor, B) methyl acetate concentration of the reaction medium; and/or C) methyl iodide concentration of the reaction medium.
    Type: Application
    Filed: October 2, 2015
    Publication date: May 19, 2016
    Inventors: Yaw-Hwa Liu, Mark O. Scates
  • Publication number: 20160137577
    Abstract: A process for producing acetic acid is disclosed, in which the methyl iodide concentration is maintained in the vapor product stream formed in a flashing step. The process includes introducing a lithium compound into the reactor and maintaining a concentration of lithium acetate in the reaction medium is in an amount from 0.3 to 0.7 wt. %. The reaction medium is fed forward to the flashing step. The methyl iodide concentration in the vapor product stream ranges from 24 to less than 36 wt. %, based on the weight of the vapor product stream. The vapor product stream is distilled in a first column to obtain an acetic acid product stream comprising acetic acid and hydrogen iodide in an amount of less than or equal to 300 wppm and/or methyl iodide in an amount from 0.1 to 6 wt. %.
    Type: Application
    Filed: October 2, 2015
    Publication date: May 19, 2016
    Inventors: Ronald D. Shaver, Yaw-Hwa Liu, Mark O. Scates
  • Publication number: 20160137574
    Abstract: Processes for producing acetic acid wherein at least one process vent stream is treated in an absorber column that utilizes a scrubber solvent, e.g., acetic acid, methanol, and/or methyl acetate to remove hydrogen iodide therefrom.
    Type: Application
    Filed: October 2, 2015
    Publication date: May 19, 2016
    Inventors: Ronald D. Shaver, Yaw-Hwa Liu, Mark O. Scates
  • Publication number: 20160137578
    Abstract: In a process for improving a carbonylation process, iron is removed to maintain an effective Space Time Yield (STY) of the rhodium catalyst of at least 80% of the maximum STY. The process comprises carbonylating methanol in a reactor in a reaction medium comprising water, a rhodium catalyst, methyl iodide and a halide salt, separating a portion of the reaction medium in a flash vessel to form a less volatile stream and a vapor product stream comprising acetic acid, recycling a liquid stream to the reactor, wherein the liquid stream comprises a portion of the less volatile stream and wherein the liquid stream comprises iron, and removing a portion of the iron from the liquid stream to maintain an effective STY of the rhodium catalyst of at least 80% of the maximum STY.
    Type: Application
    Filed: November 13, 2015
    Publication date: May 19, 2016
    Applicant: CELANESE INTERNATIONAL CORPORATION
    Inventors: Yaw-Hwa LIU, Mark O. Scates
  • Publication number: 20160137581
    Abstract: A process for producing acetic acid comprising the steps of carbonylating methanol in a reaction medium to form a crude acetic acid product; conveying the crude acetic acid product to a flash vessel at a flash flow rate; flashing the crude acetic acid product to form a first vapor stream comprising acetic acid and a liquid residue stream comprising metal catalyst and halide salt; separating the flashed vapor stream to form a second vapor stream comprising methyl iodide a sidedraw comprising purified acetic acid and water, and a liquid residue stream. The process further comprises the steps of condensing at least a portion of the second vapor stream to form at least one liquid phase and refluxing to the light ends column at least a portion of the at least one liquid phase at a reflux rate. The reflux rate is adjusted based on changes in the flash flow rate.
    Type: Application
    Filed: October 2, 2015
    Publication date: May 19, 2016
    Inventors: Ronald D. Shaver, Yaw-Hwa Liu, Mark O. Scates
  • Patent number: 9340481
    Abstract: A process for producing acetic acid is disclosed, in which the methyl iodide concentration is maintained in the vapor product stream formed in a flashing step. The process includes introducing a lithium compound into the reactor and maintaining a concentration of lithium acetate in the reaction medium is in an amount from 0.3 to 0.7 wt. %. The reaction medium is fed forward to the flashing step. The methyl iodide concentration in the vapor product stream ranges from 24 to less than 36 wt. %, based on the weight of the vapor product stream. The vapor product stream is distilled in a first column to obtain an acetic acid product stream comprising acetic acid and hydrogen iodide in an amount of less than or equal to 300 wppm and/or methyl iodide in an amount from 0.1 to 6 wt. %.
    Type: Grant
    Filed: October 2, 2015
    Date of Patent: May 17, 2016
    Assignee: CELANESE INTERNATIONAL CORPORATION
    Inventors: Ronald D. Shaver, Yaw-Hwa Liu, Mark O. Scates
  • Patent number: 9302975
    Abstract: A process for producing acetic acid is disclosed in which the methyl iodide concentration is maintained in the vapor product stream formed in a flashing step. The methyl iodide concentration in the vapor product stream ranges from 24 to less than 36 wt. % methyl iodide, based on the weight of the vapor product stream. In addition, the acetaldehyde concentration is maintained within the range from 0.005 to 1 wt. % in the vapor product stream. The vapor product stream is distilled in a first column to obtain an acetic acid product stream comprising acetic acid and up to 300 wppm hydrogen iodide and/or from 0.1 to 6 wt. % methyl iodide and an overhead stream comprising methyl iodide, water and methyl acetate.
    Type: Grant
    Filed: July 1, 2015
    Date of Patent: April 5, 2016
    Assignee: Celanese International Corporation
    Inventors: Ronald D. Shaver, Yaw-Hwa Liu, Mark O. Scates
  • Patent number: 9302969
    Abstract: Process for producing acetic acid is disclosed in which a lithium compound is added to the reaction medium to maintain a concentration of lithium acetate from 0.3 to 0.7 wt. %. The concentration of the rhodium catalyst is maintained from 300 to 3000 wppm in the reaction medium, the concentration of water is maintained from 0.1 to 4.1 wt. % in the reaction medium, and the concentration of methyl acetate is maintained from 0.6 to 4.1 wt. % in the reaction medium.
    Type: Grant
    Filed: October 2, 2015
    Date of Patent: April 5, 2016
    Assignee: CELANESE INTERNATIONAL CORPORATION
    Inventors: Mark O. Scates, Yaw-Hwa Liu
  • Patent number: 9260369
    Abstract: A process for producing an acetic acid product having low butyl acetate content via a carbonylation reaction. The carbonylation reaction is carried out at a temperature from 100 to 300° C., a hydrogen partial pressure from 0.3 to 2 atm, and a metal catalyst concentration from 100 to 3000 wppm, based on the weight of the reaction medium. The butyl acetate concentration in the acetic acid product may be controlled by removing acetaldehyde from a stream derived from the reaction medium and/or by adjusting at least one of reaction temperature, hydrogen partial pressure, and metal catalyst concentration.
    Type: Grant
    Filed: April 23, 2015
    Date of Patent: February 16, 2016
    Assignee: CELANESE INTERNATIONAL CORPORATION
    Inventors: Yaw-Hwa Liu, Mark O. Scates
  • Patent number: 9233907
    Abstract: Processes for producing acetic acid wherein at least one process vent stream is treated in an absorber column that utilizes multiple scrubber solvents, e.g., a first absorbent comprising acetic acid and a second absorbent comprising methanol and/or methyl acetate.
    Type: Grant
    Filed: April 23, 2015
    Date of Patent: January 12, 2016
    Assignee: Celanese International Corporation
    Inventors: Ronald D. Shaver, Yaw-Hwa Liu, Mark O. Scates
  • Publication number: 20150148562
    Abstract: The invention relates to processes for removing aromatics from the reactants that are fed to a carbonylation reactor. The aromatics are removed using a guard bed that comprises an adsorbent.
    Type: Application
    Filed: February 3, 2015
    Publication date: May 28, 2015
    Applicant: CELANESE INTERNATIONAL CORPORATION
    Inventors: G. Paull Torrence, Ronald David Shaver, Yaw-Hwa Liu
  • Patent number: 8952196
    Abstract: The invention relates to processes for removing aromatics from the reactants that are fed to a carbonylation reactor. The aromatics are removed using a guard bed that comprises an adsorbent.
    Type: Grant
    Filed: May 3, 2012
    Date of Patent: February 10, 2015
    Assignee: Celanese International Corporation
    Inventors: G. Paull Torrence, Ronald David Shaver, Yaw-Hwa Liu
  • Patent number: 8697908
    Abstract: A process for removing amine compounds from a process stream derived from a carbonylation process. The amine compounds may be present as iodide salts. The process stream also contains corrosion metal contaminants. The amine compounds are removed by mixing a portion of the process stream a slipstream to form an aqueous stream having a water concentration of greater than 50 wt. %. The aqueous stream is contacted with an exchange resin to remove amine compounds, as well as corrosion metal contaminants.
    Type: Grant
    Filed: May 5, 2011
    Date of Patent: April 15, 2014
    Assignee: Celanese International Corporation
    Inventors: G. Paull Torrence, Brian Hokkanen, Yaw-Hwa Liu
  • Publication number: 20120283472
    Abstract: The invention relates to processes for removing aromatics from the reactants that are fed to a carbonylation reactor. The aromatics are removed using a guard bed that comprises an adsorbent.
    Type: Application
    Filed: May 3, 2012
    Publication date: November 8, 2012
    Applicant: CELANESE INTERNATIONAL CORPORATION
    Inventors: G. Paull Torrence, Ronald David Shaver, Yaw-Hwa Liu