Patents by Inventor Hou-Min Chang

Hou-Min Chang 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).

  • Publication number: 20160355535
    Abstract: The present disclosure provides fatty acid derivatives of lignin with improved properties such as workability and other physical properties. These derivatives have the ability to form polymer blends with improved properties such as carbon fiber production and compatibilizers.
    Type: Application
    Filed: May 4, 2016
    Publication date: December 8, 2016
    Inventors: Richard A. Venditti, Siddhesh N. Pawar, Ali Ayoub, Hou-Min Chang, Hasan Jameel
  • Publication number: 20120036768
    Abstract: The presently disclosed subject matter related to methods of converting lignocellulosic materials to alcohol that include increasing the fiber consistency of enzymatic hydrolysis mixtures. More particularly, the methods involve contacting lignocellulosic biomass with an enzyme composition for a period of time, and then thickening the mixture and further hydrolyzing the thickened mixture. The thickening can be performed by filtration, optionally reusing the filtrate and/or any enzymes contained therein during the lignocellulose conversion process to increase the efficiency of the process. Hydrolysis of the thickened mixture provides a fermentable sugar mixture having a higher concentration of sugar than fermentable sugar mixtures provided from less concentrated biomass/enzyme mixtures. Compositions comprising alcohol prepared according to the presently disclosed methods are also provided.
    Type: Application
    Filed: November 23, 2009
    Publication date: February 16, 2012
    Inventors: Richard Phillips, Hasan Jameel, Hou-Min Chang
  • Publication number: 20110314726
    Abstract: A method of producing an alcohol from lignocellulosic biomass is provided wherein the lignocellulosic biomass is pretreated with an alkaline mixture of sodium carbonate and sodium sulfate, i.e., green liquor, prior to enzymatic hydrolysis and fermentation. Pretreatment with the green liquor increases the efficiency of the enzymatic hydrolysis. Both the alcohol produced from the fermentation and the lignin that dissolves into the green liquor during pretreatment can also be used as fuels.
    Type: Application
    Filed: November 23, 2009
    Publication date: December 29, 2011
    Inventors: Hasan Jameel, Richard Phillips, Hou-Min Chang, Yongcan Jin
  • Patent number: 5693185
    Abstract: A process for treating a substrate, e.g., lignocellulosic pulp or cellulosic pulps, with a mixed peracid solution comprising percarboxylic acid and Caro's acid which results in a higher conversion rate of the active oxygen in the hydrogen peroxide in order to provide an inexpensive and effective delignification and/or bleaching solution and the process for making the mixed peracid solution.
    Type: Grant
    Filed: August 30, 1996
    Date of Patent: December 2, 1997
    Assignees: North Carolina State University, E. I. Du Pont de Nemours and Company
    Inventors: Hou-Min Chang, Hasan Jameel, Junfu Song, Dingru Pan, Bijan Amini, John Robert Webster, Bruce A. Evans
  • Patent number: 5589032
    Abstract: A process for treating a substrate, e.g., lignocellulosic pulp or cellulosic pulps with a mixed peracid solution comprising percarboxylic acid and Caro's acid which results in a higher conversion rate of the active oxygen in the hydrogen peroxide in order to provide an inexpensive and effective delignification and/or bleaching solution and the process for making the mixed peracid solution.
    Type: Grant
    Filed: September 17, 1993
    Date of Patent: December 31, 1996
    Assignees: North Carolina State University, E. I. Du Pont de Nemours and Company
    Inventors: Hou-Min Chang, Hasan Jameel, Junfu Song, Dingru Pan, Bijan Amini, John R. Webster, Bruce A. Evans
  • Patent number: 5500082
    Abstract: Disclosed is a method of removing ink from xerographically printed paper. The method comprises pulping said printed paper in an aqueous slurry at a non-acidic pH to a consistency of about 8% or less. Next, added to the pulp slurry is a sufficient amount of long chain alcohol, the long chain alcohol having a melting point above room temperature, for a time sufficient with heating at a temperature sufficient, whereby an agglomeration of long chain alcohol and ink particles is formed. Next, the heating is stopped whereby the agglomeration solidifies into particles that settle to the bottom of the pulp slurry. Then, the agglomeration of solidified particles is removed from the pulp slurry thereby leaving a remaining slurry of deinked paper fiber and water. Optionally, the remaining slurry is subjected to flotation to remove substantially any remaining minute ink left particles behind after the agglomeration.
    Type: Grant
    Filed: April 26, 1993
    Date of Patent: March 19, 1996
    Assignee: North Carolina State University
    Inventors: Hou-Min Chang, Tien-Wang Wu, John A. Heitmann
  • Patent number: 5268075
    Abstract: A high-efficiency wood pulp bleaching process to produce wood pulps with higher brightness at equal chlorine dioxide usage or of equal brightness at significantly reduced chlorine dioxide usage. The process comprises reacting the chlorine dioxide with wood pulp at a pH of about 5-10 for about 5-40 minutes and then acidifying the mixture to a pH of about 1.9-4.2. The mixture is then allowed to react for about 2 or more hours to complete the two-step high/low pH bleaching process.
    Type: Grant
    Filed: February 1, 1991
    Date of Patent: December 7, 1993
    Assignee: North Carolina State University
    Inventors: Hou-min Chang, Hasan Jameel, Geoffrey E. Seger
  • Patent number: 4655926
    Abstract: A process of treating effluent from a pulp or paper-making operation to decolorize the effluent is provided in which a white-rot fungus is germinated and grown and is then induced into a secondary metabolic state. The white-rot fungus is then immersed in the effluent where the fungus' active ligninolytic system decolorizes the effluent. The rate of fungal activity and the active lifetime of the fungus is increased by the addition to the effluent of at least one member of the class consisting of nutrient nitrogen, nutrient minerals, and a detergent.
    Type: Grant
    Filed: May 29, 1984
    Date of Patent: April 7, 1987
    Assignee: North Carolina State University
    Inventors: Hou-min Chang, Thomas W. Joyce, Thomas K. Kirk
  • Patent number: 4554075
    Abstract: A process of degrading chloro-organics contained in liquid waste or effluent utilizes a white-rot fungus as the active ingredient in the chloro-organic degradation. The white-rot fungus is grown in the presence of certain nutrients including nutrient nitrogen and is then caused to enter a secondary metabolic state through nitrogen starvation. The fungus is then immersed in the liquid containing chloro-organics for a time period sufficient for the fungus to degrade the chloro-organics. At least periodically during the degradation period, the fungus is exposed to an oxygen enriched atmosphere. The efficacy and active lifetime of the fungus may be increased by the addition to the liquid of at least one member of the class consisting of nitrogen, a mixture of nutrient minerals, and a biological detergent.
    Type: Grant
    Filed: May 29, 1984
    Date of Patent: November 19, 1985
    Assignee: North Carolina State University
    Inventors: Hou-min Chang, Thomas W. Joyce, Thomas K. Kirk, Van-Ba Huynh
  • Patent number: 4420369
    Abstract: Pulp mill bleach plant caustic extraction effluent is decolorized using a primary or other sludge from a pulp and paper mill. The sludge is acidified and mixed with the effluent. After a short incubation period, the mixture of acidified sludge and effluent is raised to at least neutral pH, causing precipitation of most of the color in the effluent. The precipitated color may then easily be separated from the liquor by any conventional clarification technique. The method avoids the consumption of large quantities of expensive reagents or high transportation costs associated with the prior art decolorization techniques used on such effluent.
    Type: Grant
    Filed: February 25, 1982
    Date of Patent: December 13, 1983
    Assignee: The United States of America as represented by the Secretary of Agriculture
    Inventors: David C. Eaton, Thomas K. Kirk, Hou-min Chang
  • Patent number: 4087316
    Abstract: Cellulosic fibers are removed from seed hulls such as cottonseed hulls by a process including (a) in the absence of mechanical action sufficient to cause degradation of fiber properties, contacting the seed hulls which comprise both cellulosic fibers (linters and hull fibers) and non-fibrous hull components with an alkaline solution and an oxygen-containing gas until the cellulosic fibers are substantially free of the non-fibrous hull components, and (b) recovering the cellulosic fibers from the non-fibrous hull components so as to produce readily washable cellulosic fibers having substantially unimpaired mechanical properties. The cellulosic fibers may then be washed and separated according to known fiber fractionation procedures. The cellulosic fibers produced according to this improved process have substantially unimpaired mechanical properties and contain substantially no polyphenolic materials or extraneous color components.
    Type: Grant
    Filed: September 15, 1976
    Date of Patent: May 2, 1978
    Assignee: Cotton Incorporated
    Inventors: Gay M. Jividen, Hou-Min Chang, R. Heath Reeves, Chen-Loung Chen