Patents by Inventor Hans E. Grethlein

Hans E. Grethlein 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: 8211679
    Abstract: Ethanol and other liquid products produced by contacting carbon monoxide (CO) and/or a mixture of CO2 (carbon dioxide) and H2 (hydrogen) with a microorganism in a bioreactor are separated using a combination of distillation and vapor permeation membranes. The bioreactor passes an effluent with an ethanol concentration of 1 to 6 wt % to a distillation column that produces an overhead vapor stream enriched in ethanol. A series of vapor permeation membranes retain ethanol as retentate and produce a 99 wt % or higher ethanol product. Ethanol depleted permeate streams flow back to the column and the bioreactor. Coupling a bioreactor with distillation and pervaporation efficiently and economically separates ethanol when present at low concentration in an aqueous fermentation broth. The separation arrangement may also include a flash zone ahead of the distillation column to raise the concentration of the ethanol in the input stream to the distillation column.
    Type: Grant
    Filed: February 25, 2008
    Date of Patent: July 3, 2012
    Assignee: Coskata, Inc.
    Inventors: Rathin Datta, Rahul Basu, Hans E. Grethlein, Richard W. Baker, Yu Huang
  • Publication number: 20090215139
    Abstract: Ethanol and other liquid products produced by the contacting CO and/or a mixture of CO2 and H2 with a microorganism in a bioreactor are separated using a combination of distillation and vapor permeation membranes. The bioreactor passes an effluent with an ethanol concentration of 1 to 6 wt % to a distillation column that produces an overhead vapor stream enriched in ethanol. A series of vapor permeation membranes retain ethanol as retentate and produce a 99 wt % or higher ethanol product. Ethanol depleted permeate streams flow back to the column and the bioreactor. Coupling a bioreactor with distillation and pervaporation efficiently and economically separates ethanol when present at low concentration in an aqueous fermentation broth. The separation arrangement may also include a flash zone ahead of the distillation column to raise the concentration of the ethanol in the input stream to the distillation column.
    Type: Application
    Filed: February 25, 2008
    Publication date: August 27, 2009
    Inventors: Rathin Datta, Rahul Basu, Hans E. Grethlein
  • Patent number: 6143534
    Abstract: Lignite is treated with ligninase source to enhance its reactivity. In one embodiment, lignite is gasified in a subterranean reactor by simultaneous digestion by anaerobic ligninase producers, such as termite microflora, and acid formers and methanogens. In another embodiment, the lignite is treated with ligninase prior to digestion by the acid formers and methanogens. If desired, the lignite may be pretreated by alkaline hydrolysis.
    Type: Grant
    Filed: December 24, 1991
    Date of Patent: November 7, 2000
    Assignee: Reliant Energy Incorporated
    Inventors: William M. Menger, Ernest E. Kern, O. C. Karkalits, Donald L. Wise, Alfred P. Leuschner, David Odelson, Hans E. Grethlein
  • Patent number: 5167799
    Abstract: An apparatus for simulating the operation of a full-scale belt filter press consists of a support base, a filter belt and a press belt each anchored at one end to the support base and passing over a static curved pressure face and a winch for exerting a pulling force on the press belt against the static curved press face to remove water from a sample of slurry on or within the belts. An improvement in the method of removing liquid from a slurry with a belt filter press also is disclosed which consists of pulling the pair of belts containing a slurry against a static curved pressure face to force liquid out of the slurry.
    Type: Grant
    Filed: August 1, 1991
    Date of Patent: December 1, 1992
    Assignee: Michigan Biotechnology Institute
    Inventors: Blaine F. Severin, Daniel J. Wagner, Hans E. Grethlein, Robert F. Hickey
  • Patent number: 5124004
    Abstract: A method of distillation employing a heat pump (which may be driven by a compressor) using a vapor stream from within the distillation system as a heat source and a liquid stream from within the distillation system as a heat sink. The selection of heat-source vapors and heat-sink liquid is such that at least one is withdrawn from the phase-contracting region of the distillation system. The return of streams withdrawn from the phase-contacting region of the distillation system to the distillation system is such that at least one of the streams is returned at a temperature different from that of the point from which it was withdrawn, and all withdrawn streams are returned in manner such that a stream removed as vapor is returned at a point with a temperature at most that at the point it was withdrawn, and a stream removed as liquid is returned at a point with a temperature at least that at which it was withdrawn.
    Type: Grant
    Filed: February 6, 1990
    Date of Patent: June 23, 1992
    Assignee: Trustees of Dartmouth College
    Inventors: Hans E. Grethlein, Lee R. Lynd
  • Patent number: 4961826
    Abstract: A method of distillation employing a heat pump (which may be driven by a compressor) using a vapor stream from within the distillation system as a heat source and a liquid stream from within the distillation system as a heat sink. The selection of heat-source vapors and heat-sink liquid is such that at least one is withdrawn from the phase-contacting region of the distillation system. The return of streams withdrawn from the phase-contacting region of the distillation system to the distillation system is such that at least one of the streams is returned at a temperature different from that of the point from which it was withdrawn, and all withdrawn streams are returned in manner such that a stream removed as vapor is returned at a point with a temperature at most that at the point it was withdrawn, and a stream removed as liquid is returned at a point with a temperature at least that at which it was withdrawn.
    Type: Grant
    Filed: August 19, 1986
    Date of Patent: October 9, 1990
    Assignee: Trustees of Dartmouth College
    Inventors: Hans E. Grethlein, Lee H. Lynd
  • Patent number: 4818295
    Abstract: A system is provided to produce sugars from a liquid-solid mixture containing biomass, and an acid, wherein the mixture is heated to an appropriate temperature to achieve hydrolysis. The liquid-solid mixture is introduced as a stream into the circular-cylindrical chamber of a cyclone reaction vessel and steam is introduced to the vessel to provide the necessary heat for hydrolysis as well as to establish the liquid-solid mixture in a rotary flow field whereby the liquids and solids of the mixture move along spiral paths within the chamber. The liquid-solid mixture may be introduced at the periphery of the chamber to spiral down toward and be discharged at or near the center of the chamber. Because of differing mass, the solid particles in the mixture move radially inward at a different rate than the liquid and that rate is controlled to maximize the hydrolysis of the solids and to minimize the decomposition of sugars, thus formed.
    Type: Grant
    Filed: April 4, 1986
    Date of Patent: April 4, 1989
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Alvin O. Converse, Hans E. Grethlein, Joseph E. Holland
  • Patent number: 4626321
    Abstract: A method of distillation employing a heat pump (which may be driven by a compressor) using a vapor stream from within the distillation system as a heat source and a liquid stream from within the distillation system as a heat sink. The selection of heat-source vapors and heat-sink liquid is such that at least one is withdrawm from the phase-contacting region of the distillation system. The return of streams withdrawm from the phase-contacting region of the distillation system to the distillation system is such that at least one of the streams is returned at a temperature different from that of the point from which it was withdrawn, and all withdrawn streams are returned in manner such that a stream removed as vapor is returned at a point with a temperature at most that at the point it was withdrawn, and a stream removed as liquid is returned at a point with a temperature at least that at which it was withdrawn.
    Type: Grant
    Filed: February 13, 1986
    Date of Patent: December 2, 1986
    Assignee: Trustees of Dartmouth College
    Inventors: Hans E. Grethlein, Lee H. Lynd
  • Patent number: 4556430
    Abstract: A process for hydrolysis of biomass wherein the biomass is mixed with a small amount of an aqueous acid to produce a wet meal. A non-aqueous carrier fluid is used to form a slurry of the biomass, and the temperature and pressure are established at appropriate levels to effect hydrolysis of the biomass to decomposition products that include sugar for a time period that is sufficient for the hydrolysis to occur.
    Type: Grant
    Filed: November 5, 1984
    Date of Patent: December 3, 1985
    Assignee: Trustees of Dartmouth College
    Inventors: Alvin O. Converse, Hans E. Grethlein
  • Patent number: 4237226
    Abstract: Processes for treating cellulosic substances prior to hydrolysis which lead to shortening hydrolysis time and to increasing sugar yield. As exemplary, an aqueous slurry of the cellulosic substance is acidified and heated to and maintained at a temperature to produce a change in the cellulosic structure; the heating period is controlled so that there is little glucose formation. The pretreated cellulose may be subsequently hydrolyzed by acid or enzyme.
    Type: Grant
    Filed: February 23, 1979
    Date of Patent: December 2, 1980
    Assignee: Trustees of Dartmouth College
    Inventor: Hans E. Grethlein