Patents by Inventor An-I Yeh

An-I Yeh 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).

  • Dehydration of ethanol by extractive distillation
    Patent number: 4631115
    Abstract: Water cannot be completely removed from ethanol by distillation because of the presence of the minimum azeotrope. Ethanol can be readily dehydrated by using extractive distillation in which the water is removed as overhead product and the ethanol and extractive agent as bottoms and subsequently separated by conventional rectification. Typical examples of suitable extractive agents are methyl benzoate; trimellitic anhydride and methyl benzoate; dipropylene glycol dibenzoate, ethyl salicylate and resorcinol.
    Type: Grant
    Filed: December 23, 1985
    Date of Patent: December 23, 1986
    Inventors: Lloyd Berg, An-I Yeh
  • Separation of methyl acetate from methanol by extractive distillation
    Patent number: 4597834
    Abstract: Methyl acetate cannot be completely removed from methyl acetate - methanol mixtures by distillation because of the presence of the minimum binary azeotrope. Methyl acetate can be readily removed from mixtures containing it and methanol by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, nitrogenous and/or sulfur containing organic compound or a mixture of these. Typical examples of effective agents are dimethylformamide; dimethylsulfoxide plus tetraethylene glycol, dimethylsulfoxide plus 1,5-pentanediol plus 1,6-hexanediol.
    Type: Grant
    Filed: February 17, 1984
    Date of Patent: July 1, 1986
    Inventors: Lloyd Berg, An-I Yeh
  • Separation of n-propyl acetate from n-propanol by extractive distillation
    Patent number: 4592805
    Abstract: n-Propyl acetate cannot be completely removed from n-propyl acetate - n-propanol - water mixtures by distillation because of the presence of the minimum ternary azeotrope. n-Propyl acetate can be readily removed from mixtures containing it, n-propanol and water by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, nitrogenous and/or sulfur containing organic compound or a mixture of these. Examples of effective agents are N,N-dimethylacetamide; acetamide and triethylene glycol; acetamide and N,N-dimethylacetamide and triethanolamine.
    Type: Grant
    Filed: December 14, 1984
    Date of Patent: June 3, 1986
    Inventors: Lloyd Berg, An-I Yeh
  • Separation of m-xylene from o-xylene by extractive distillation
    Patent number: 4585526
    Abstract: m-Xylene is difficult to separate from o-xylene by conventional rectification or distillation because of the close proximity of their boiling points. m-Xylene can be readily separated from o-xylene by using extractive distillation in which the extractive agent comprises propoxypropanol; propoxypropanol and 1,4-butanediol; ethyl benzoate and ethylene glycol phenyl ether and benzyl alcohol.
    Type: Grant
    Filed: October 1, 1984
    Date of Patent: April 29, 1986
    Inventors: Lloyd Berg, An-I Yeh
  • Separation of isopropyl ether from isopropanol and water by extractive distillation
    Patent number: 4566948
    Abstract: Isopropyl ether cannot be completely removed from isopropyl ether-isopropanol-water mixtures by distillation because of the presence of the minimum ternary azeotrope. Isopropyl ether can be readily removed from mixtures containing it, isopropanol and water by using extractive distillation in which the extractive distillation agent is dimethylsulfoxide with or without a mixture of higher boiling oxygenated and/or nitrogenous organic compounds. Typical examples are dimethylsulfoxide; dimethylsulfoxide and ethylene glycol; dimethylsulfoxide, dimethylformamide and 1,4-butanediol.
    Type: Grant
    Filed: December 20, 1984
    Date of Patent: January 28, 1986
    Inventors: Lloyd Berg, An-I Yeh
  • Separation of isopropyl ether from acetone by extractive distillation
    Patent number: 4551207
    Abstract: Isopropyl ether cannot be completely removed from isopropyl ether-acetone mixtures by distillation because of the presence of the minimum binary azeotrope. Isopropyl ether can be readily removed from mixtures containing it and acetone by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, nitrogenous and/or sulfur containing compound or a mixture of these. Typical examples of effective agents are: dimethylsulfoxide; sulfolane and propylene glycol; adiponitrile, glycerine and ethylene glycol.
    Type: Grant
    Filed: February 3, 1984
    Date of Patent: November 5, 1985
    Inventors: Lloyd Berg, An-I Yeh
  • Separation of methanol from methyl acetate by extractive distillation
    Patent number: 4549938
    Abstract: Methanol cannot be completely removed from methanol-methyl acetate mixtures by distillation because of the presence of the minimum binary azeotrope. Methanol can be readily removed from mixtures containing it and methyl acetate by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated or nitrogenous organic compound or a mixture of these. Typical examples of effective agents are: ethylene glycol phenyl ether, ethylene carbonate, nitromethane, 2-nitrotoluene, 1-nitropropane plus propylene carbonate.
    Type: Grant
    Filed: March 23, 1984
    Date of Patent: October 29, 1985
    Inventors: Lloyd Berg, An-I Yeh
  • Separation of isopropyl ether from methyl ethyl ketone by extractive distillation
    Patent number: 4544454
    Abstract: Isopropyl ether cannot be completely removed from isopropyl ether - methyl ethyl ketone mixtures by distillation because of the presence of the minimum binary azeotrope. Isopropyl ether can be readily removed from mixtures containing it and methyl ethyl ketone by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated and/or nitrogenous organic compound or a mixture of these. Typical examples of effective agents are adiponitrile; ehtylene carbonate plus dimethylformamide; adiponitrile plus dimethylformamide plus glycerine.
    Type: Grant
    Filed: February 10, 1984
    Date of Patent: October 1, 1985
    Inventors: Lloyd Berg, An-I Yeh
  • Separation of methyl acetate from methanol by extractive distillation
    Patent number: 4543164
    Abstract: Methyl acetate cannot be completely removed from methyl acetate-methanol mixtures by distillation because of the presence of the minimum binary azeotrope. Methyl acetate can be readily removed from mixtures containing it and methanol by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, nitrogenous and/or sulfur containing organic compound or a mixture of these. Typical examples of effective agents are dimethylsulfoxide; glycerine plus propylene glycol; ethylene glycol plus DMSO plus 1,5-pentanediol. Methanol can be removed as the overhead product from methyl acetate when the extractive distillation agent is nitrobenzene, propylene carbonate or ethylene glycol phenyl ether.
    Type: Grant
    Filed: April 14, 1983
    Date of Patent: September 24, 1985
    Inventors: Lloyd Berg, An-I Yeh
  • Separation of n-butyl acetate from n-butanol by extractive distillation
    Patent number: 4525245
    Abstract: n-Butyl acetate cannot be completely removed from n-butyl acetate - n-butanol - water mixtures by distillation because of the presence of the minimum ternary azeotrope. n-Butyl acetate can be readily removed from mixtures containing it, n-butanol and water by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, nitrogenous and/or sulfur containing organic compound or a mixture of these. Typical examples of effective agents are dimethylsulfoxide; dimethylsulfoxide and 1,4-butanediol; dimethylsulfoxide, dimethylformamide and 1,6-hexanediol.
    Type: Grant
    Filed: May 7, 1984
    Date of Patent: June 25, 1985
    Inventors: Lloyd Berg, An-I Yeh
  • Separation of isopropyl ether from isopropanol and water by extractive distillation
    Patent number: 4510022
    Abstract: Isopropyl ether cannot be completely removed from isopropyl ether-isopropanol-water mixtures by distillation because of the presence of the minimum ternary azeotrope. Isopropyl ether can be readily removed from mixtures containing it, isopropanol and water by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, nitrogenous and/or sulfur containing organic compound or a mixture of these. Typical examples of effective agents are ethylene glycol; dimethylsulfoxide plus propylene glycol; dimethylsulfoxide plus dimethylformamide plus diethylene glycol diethyl ether.
    Type: Grant
    Filed: August 8, 1983
    Date of Patent: April 9, 1985
    Inventors: Lloyd Berg, An-I Yeh
  • Separation of n-butyl acetate from n-butanol by extractive distillation
    Patent number: 4507176
    Abstract: n-Butyl acetate cannot be completely removed from n-butyl acetate-n-butanol--water mixtures by distillation because of the presence of the minimum ternary azeotrope. n-Butyl acetate can be readily removed from mixtures containing it, n-butanol and water by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, nitrogenous and/or sulfur containing organic compound or a mixture of these. Typical examples of effective agents are N,N-dimethylacetamide, dimethylsulfoxide and acetamide, ethylene glycol propylene glycol, dimethylsulfoxide and acetamide.
    Type: Grant
    Filed: May 7, 1984
    Date of Patent: March 26, 1985
    Inventors: Lloyd Berg, An-I Yeh
  • Separation of methanol from acetone by extractive distillation
    Patent number: 4501645
    Abstract: Methanol cannot be completely removed from its mixture with acetone by distillation because of the presence of the minimum binary azeotrope. Methanol can be readily removed from mixtures containing it and acetone by using extractive distillation to bring off the methanol as overhead product in a rectification column by using extractive distillation in which the extractive distillation agent is an effective higher boiling organic compound or a mixture of these. Typical examples of effective agents are acetophenone, 3-pentanone, 2,4-pentanedione, ethylacetoacetate, 2-butanone plus benzil.
    Type: Grant
    Filed: November 1, 1983
    Date of Patent: February 26, 1985
    Inventors: Lloyd Berg, An-I Yeh
  • Separation of m-xylene from o-xylene by extractive distillation
    Patent number: 4488937
    Abstract: m-Xylene is difficult to separate from o-xylene by conventional rectification or distillation because of the close proximity of their boiling points. m-Xylene can be readily separated from o-xylene by using extractive distillation in which the extractive agent is ethyl-2-hydroxybenzoate; propoxypropanol puls 1,4-butanediol; sulfolane plus dimethylsulfoxide plus ethyl benzoate.
    Type: Grant
    Filed: April 11, 1984
    Date of Patent: December 18, 1984
    Inventors: Lloyd Berg, An-I Yeh
  • Separation of isopropyl ether from acetone by extractive distillation
    Patent number: 4459179
    Abstract: Isopropyl ether cannot be completely removed from isopropyl ether-acetone mixtures by distillation because of the presence of the minimum binary azeotrope. Isopropyl ether can be readily removed from mixtures containing it and acetone by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated or nitrogenous organic compound or a mixture of these. Typical examples of effective agents are: dimethylsulfoxide; sulfolane and propylene glycol; glycerine, ethylene glycol and adiponitrile.
    Type: Grant
    Filed: January 6, 1983
    Date of Patent: July 10, 1984
    Inventors: Lloyd Berg, An-I Yeh
  • Separation of isopropyl ether from methyl ethyl ketone by extractive distillation
    Patent number: 4459178
    Abstract: Isopropyl ether cannot be completely removed from isopropyl ether - methyl ethyl ketone mixtures by distillation because of the presence of the minimum binary azeotrope. Isopropyl ether can be readily removed from mixtures containing it and methyl ethyl ketone by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, nitrogenous and/or sulfur containing organic compound or a mixture of these. Typical examples of effective agents are sulfolane; ethylene carbonate plus dimethylsulfoxide; adiponitrile plus dimethylformamide plus glycerine.
    Type: Grant
    Filed: April 25, 1983
    Date of Patent: July 10, 1984
    Inventors: Lloyd Berg, An-I Yeh