Patents by Inventor David A. Glassner

David A. Glassner 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: 20090226990
    Abstract: Methods for producing a biofuel are provided. Also provided are biocatalysts that convert a feedstock to a biofuel.
    Type: Application
    Filed: October 31, 2008
    Publication date: September 10, 2009
    Applicant: GEVO, Inc.
    Inventors: Andrew C. Hawkins, David A. Glassner, Thomas Buelter, James Wade, Peter Meinhold, Matthew W. Peters, Patrick R. Gruber, William A. Evanko, Aristos A. Aristidou
  • Publication number: 20090215137
    Abstract: Methods for producing a biofuel precursor are provided. Also provided are biocatalysts that convert a feedstock to a biofuel precursor.
    Type: Application
    Filed: October 31, 2008
    Publication date: August 27, 2009
    Applicant: GEVO, INC.
    Inventors: Andrew C. Hawkins, David A. Glassner, Thomas Buelter, James Wade, Peter Meinhold, Matthew W. Peters, Patrick R. Gruber, William A. Evanko, Aristos A. Aristidou
  • Publication number: 20090176286
    Abstract: The invention herein is an efficient, flexible biomass fractionation process comprising digesting a lignocellulosic-biomass material at about 120-220° C. and a pH of less than about 4, in an aqueous mixture containing an effective concentration of at least one solvent for lignin, and separating to recover a solid phase that contains a large fraction of the cellulose originally in the starting lignocellulosic material and a liquid phase that contains most of the lignin and hemicellulose originally in the starting lignocellulosic biomass. The process can produce a solid phase that contains at least 75% cellulose and less than 10% lignin. The cellulose-rich solid product can be converted very efficiently to glucose. The solid product can also be used in commercial pulp applications, such as papermaking or fluff pulp. Hemicellulose sugars and lignin can be used directly or converted to other products.
    Type: Application
    Filed: November 15, 2006
    Publication date: July 9, 2009
    Inventors: Ryan P. O'Connor, Robert Wooley, Jeffrey John Kolstad, Robert Thomas Kean, David A. Glassner, Beth Mastel, Jon Michael Ritzenthaler, Robert Henry Birk, Jeffrey Warwick, James R. Hettenhaus, Rebecca Kerin Brooks
  • Publication number: 20090171129
    Abstract: This invention is directed to methods for recovery of C3-C6 alcohols from dilute aqueous solutions, such as fermentation broths. Such methods provide improved volumetric productivity for the fermentation and allows recovery of the alcohol. Such methods also allow for reduced energy use in the production and drying of spent fermentation broth due to increased effective concentration of the alcohol product by the simultaneous fermentation and recovery process which increases the quantity of alcohol produced and recovered per quantity of fermentation broth dried. Thus, the invention allows for production and recovery of C3-C6 alcohols at low capital and reduced operating costs.
    Type: Application
    Filed: December 23, 2008
    Publication date: July 2, 2009
    Applicant: Gevo, Inc.
    Inventors: William A. Evanko, Aharon M. Eyal, David A. Glassner, Fudu Miao, Aristos A. Aristidou, Kent Evans, Patrick R. Gruber, Andrew C. Hawkins
  • Patent number: 7522784
    Abstract: The invention relates to an electro-optic directional coupler suitable for use as a variable optical attenuator at reduced voltages compared to those known in the prior art. The present invention has found that by careful selection of an asymmetric directional coupler geometry, the transfer function of the device can be shifted so that it has an operating point between maximum and minimum transmission. Signal electrodes driven in push pull configuration advantageously use this operating point to achieve significant reduction in operating voltages for switching to maximum or minimum transmission. Asymmetry is created in the directional coupler by forming the waveguides to have different propagation constants by a difference in waveguide width, depth, index of refraction or index profile.
    Type: Grant
    Filed: February 9, 2007
    Date of Patent: April 21, 2009
    Assignee: JDS Uniphase Corporation
    Inventors: Karl Kissa, David Glassner
  • Publication number: 20070201784
    Abstract: The invention relates to an electro-optic directional coupler suitable for use as a variable optical attenuator at reduced voltages compared to those known in the prior art. The present invention has found that by careful selection of an asymmetric directional coupler geometry, the transfer function of the device can be shifted so that it has an operating point between maximum and minimum transmission. Signal electrodes driven in push pull configuration advantageously use this operating point to achieve significant reduction in operating voltages for switching to maximum or minimum transmission. Asymmetry is created in the directional coupler by forming the waveguides to have different propagation constants by a difference in waveguide width, depth, index of refraction or index profile.
    Type: Application
    Filed: February 9, 2007
    Publication date: August 30, 2007
    Applicant: JDS Uniphase Corporation
    Inventors: Karl Kissa, David Glassner
  • Patent number: 5168055
    Abstract: A process for economically producing highly purified succinic acid comprises growing a succinate-producing microorganism on a low cost carbohydrate substrate; simultaneously neutralizing the fermentation broth and precipitating the succinate as calcium succinate by adding a calcium ion source to form calcium succinate; isolating the calcium succinate; slurrying the calcium succinate in water and treating it with sulfuric acid to form calcium sulfate and succinic acid; and then treating the succinic acid with first a strongly acidic ion exchanger and then a weakly basic ion exchanger to remove impurities and obtain a highly purified succinic acid product. In a preferred embodiment, the calcium succinate is isolated from the fermentation broth by filtration; the filtrate is heated to precipitate additional calcium succinate; and, the spent filtrate which contains nutrients is recycled to the fermentor.
    Type: Grant
    Filed: June 28, 1989
    Date of Patent: December 1, 1992
    Inventors: Rathin Datta, David A. Glassner, Mahendra K. Jain, John R. Vick Roy
  • Patent number: 5143834
    Abstract: A process for producing and purifying succinic acid comprises growing a succinate salt-producing microorganism on an inexpensive substrate containing carbohydrate, other nutrients, sodium ions and tryptophan under a CO.sub.2 partial pressure until most of the carbohydrate is converted to succinate. The fermentation broth is then electrodialyzed to recover and concentrate the succinate salt in an aqueous stream which is subjected to water-splitting electrodialysis to form base and a succinic acid product. The resulting succinc acid product is treated first with a strongly acidic ion exchanger in the acid form to remove any sodium or other cations and then treated with a weakly basic ion exchanger in the free base form to remove any sulfate ions or sulfuric acid and to obtain a highly purified succinic acid product.
    Type: Grant
    Filed: March 17, 1989
    Date of Patent: September 1, 1992
    Inventors: David A. Glassner, Rathin Datta
  • Patent number: 5063156
    Abstract: A process including multistage continuous fermentation followed by batch fermentation with carefully chosen temperatures for each fermentation step, combined with an asporogenic strain of C. acetobutylicum and a high carbohydrate substrate concentration yields extraordinarily high butanol and total solvents concentrations.
    Type: Grant
    Filed: April 30, 1990
    Date of Patent: November 5, 1991
    Inventors: David A. Glassner, Mahendra K. Jain, Rathin Datta
  • Patent number: 5034105
    Abstract: A process for preparing a carboxylic acid of high purity comprises preparing an undersaturated solution of a salt of the carboxylic acid; subjecting the undersaturated salt solution to water-splitting electrodialysis to form base and a supersaturated solution of the carboxylic acid; and, then crystallizing the carboxylic acid from the supersaturated solution. In the preferred embodiment, the undersaturated solution is a fermentation broth containing sodium succinate and the carboxylic acid obtained is succinic acid.
    Type: Grant
    Filed: July 27, 1989
    Date of Patent: July 23, 1991
    Assignee: Michigan Biotechnology Institute
    Inventors: Kris A. Berglund, Ponnampalam Elankovan, David A. Glassner