Patents by Inventor Mark T. Holtzapple

Mark T. Holtzapple 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: 6478965
    Abstract: Dilute solutions of fermentation sales may be concentrated by extracting water using low-miscibility, low-molecular-weight secondary and tertiary amines, e.g. triethylamine (TEA), diisopropyl amine (DIA), N,N-diethylmethylamine (DEMA), and mixtures thereof. At 30° C.-55° C., which corresponds to typical fermentation temperatures, these low-molecular-weight amines or their mixtures, can extract large amounts of water from dilute aqueous solutions containing fermentation salts. Thus, dilute fermentation salt solutions can be concentrated by selectively removing water. At these low temperatures, the amine phase contains 20-35% water and a much reduced quantity of fermentation salt. When the temperature is raised, water phases out of the amine, allowing the amine to be recycled and reused to extract additional water. Using this approach, about 82.
    Type: Grant
    Filed: November 16, 1999
    Date of Patent: November 12, 2002
    Assignee: The Texas A&M University System
    Inventors: Mark T. Holtzapple, Richard R. Davison, Torsten Luettich
  • Patent number: 6427453
    Abstract: Novel vapor compression evaporative cooling systems which use water as a refrigerant are provided, as are methods for using same. Also provided are novel compressors, compressor components, and means for removing noncondensibles useful in such cooling systems.
    Type: Grant
    Filed: July 31, 1998
    Date of Patent: August 6, 2002
    Assignee: The Texas A&M University System
    Inventors: Mark T. Holtzapple, Richard Davison, G. Andrew Rabroker
  • Publication number: 20020088243
    Abstract: Novel vapor compression evaporative cooling systems which use water as a refrigerant are provided, as are methods for using same. Also provided are novel compressors, compressor components, and means for removing noncondensibles useful in such cooling systems.
    Type: Application
    Filed: September 28, 2001
    Publication date: July 11, 2002
    Inventors: Mark T. Holtzapple, Richard Davison, G. Andrew Rabroker
  • Patent number: 6395926
    Abstract: The invention provides a method for recovering low-boiling acids from a concentrated solution of the calcium salt of the acid by treating the concentrated solution of calcium salts of the low-boiling acids with a high molecular weight tertiary amine and carbon dioxide.
    Type: Grant
    Filed: June 15, 2001
    Date of Patent: May 28, 2002
    Assignee: Texas A&M University System
    Inventors: Mark T. Holtzapple, Richard R. Davison
  • Publication number: 20020038058
    Abstract: This invention provides a method for thermally converting volatile fatty acid (VFA) salts to ketones by mixing dry calcium salts of VFAs with hot heat transfer agent in an evacuated container, thereby causing thermal decomposition of the calcium salts of VFAs to form ketone-containing vapor and calcium carbonate; and separating the ketone-containing vapor from the calcium carbonate and heat transfer agent by condensing a mixture of ketones from the ketone-containing vapor. This invention also provides a process for conversion of VFA salts, produced by anaerobic fermentation of cellulosic biomass, into liquid fuels, volatile fatty acids, aldehydes, alcohols, and lactic acid.
    Type: Application
    Filed: June 15, 2001
    Publication date: March 28, 2002
    Inventors: Mark T. Holtzapple, Richard R. Davison
  • Publication number: 20020014069
    Abstract: An engine is disclosed. According to one embodiment of the present invention, the engine comprises a compressor, and combustor, and an expander. The compressor compresses ambient air. The combustor bums the compressed air, and produces exhaust gasses. The expander receives the exhaust gases from the combustor, and expands the exhaust gasses. The compressor may be a gerotor compressor or a piston compressor having variable-dead-volume control. The expander may be a gerotor expander or a piston expander having variable-dead-volume control. In another embodiment, an engine comprises a piston compressor, a combustor, a piston expander, and a pressure tank. The piston compressor compresses ambient air. The combustor bums the compressed air, and produces exhaust gasses. The piston expander receives the exhaust gasses from the combustor, and expands the exhaust gasses. The pressure tank receives and stores the compressed air from the compressor.
    Type: Application
    Filed: August 16, 2001
    Publication date: February 7, 2002
    Inventors: Mark T. Holtzapple, Andrew G. Rabroker
  • Patent number: 6336317
    Abstract: An engine is disclosed. According to one embodiment of the present invention, the engine comprises a compressor, and combustor, and an expander. The compressor compresses ambient air. The combustor burns the compressed air, and produces exhaust gasses. The expander receives the exhaust gases from the combustor, and expands the exhaust gasses. The compressor may be a gerotor compressor or a piston compressor having variable-dead-volume control. The expander may be a gerotor expander or a piston expander having variable-dead-volume control. In another embodiment, an engine comprises a piston compressor, a combustor, a piston expander, and a pressure tank. The piston compressor compresses ambient air. The combustor burns the compressed air, and produces exhaust gasses. The piston expander receives the exhaust gasses from the combustor, and expands the exhaust gasses. The pressure tank receives and stores the compressed air from the compressor.
    Type: Grant
    Filed: July 30, 1999
    Date of Patent: January 8, 2002
    Assignee: The Texas A&M University System
    Inventors: Mark T. Holtzapple, G. Andrew Rabroker
  • Publication number: 20010022755
    Abstract: A mixer for producing a substance mixture includes a rotatable shaft and a body submersible within a first substance. The body includes a first end and a second end. The first end is coupled to the shaft, and the second end includes an outwardly flared opening. The mixer also includes a plurality of apertures disposed on a wall of the body. Rotation of the body draws the first substance and a second substance into an internal area of the body and dispels the substance mixture outwardly through the apertures. The mixer may also include a diverter for diverting the substance mixture toward the apertures. The mixer may further include internally formed vanes to increase a substance flow rate into the mixer. Screens may also be disposed outwardly from the apertures to enhance mixing of the first and second substances.
    Type: Application
    Filed: December 19, 2000
    Publication date: September 20, 2001
    Inventors: Mark T. Holtzapple, Salvador Aldrett Lee, Edith R. Isbell
  • Patent number: 6262313
    Abstract: This invention provides a method for thermally converting volatile fatty acid (VFA) salts to ketones by mixing dry calcium salts of VFAs with hot heat transfer agent in an evacuated container, thereby causing thermal decomposition of the calcium salts of VFAs to form ketone-containing vapor and calcium carbonate; and separating the ketone-containing vapor from the calcium carbonate and heat transfer agent by condensing a mixture of ketones from the ketone-containing vapor. This invention also provides a process for conversion of VFA salts, produced by anaerobic fermentation of cellulosic biomass, into liquid fuels, volatile fatty acids, aldehydes, alcohols, and lactic acid.
    Type: Grant
    Filed: December 22, 1999
    Date of Patent: July 17, 2001
    Assignee: Texas A&M University System
    Inventors: Mark T. Holtzapple, Richard R. Davison
  • Patent number: 6043392
    Abstract: This invention provides a method for thermally converting volatile fatty acid (VFA) salts to ketones by mixing dry calcium salts of VFAs with hot heat transfer agent in an evacuated container, thereby causing thermal decomposition of the calcium salts of VFAs to form ketone-containing vapor and calcium carbonate; and separating the ketone-containing vapor from the calcium carbonate and heat transfer agent by condensing a mixture of ketones from the ketone-containing vapor. This invention also provides a process for conversion of VFA salts, produced by anaerobic fermentation of cellulosic biomass, into liquid fuels, volatile fatty acids, aldehydes, alcohols, and lactic acid.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: March 28, 2000
    Assignee: Texas A&M University System
    Inventors: Mark T. Holtzapple, Richard R. Davison
  • Patent number: 5986133
    Abstract: Dilute solutions of fermentation sales may be concentrated by extracting water using low-miscibility, low-molecular-weight secondary and tertiary amines, e.g. triethylamine (TEA), diisopropyl amine (DIA), N,N-diethylmethylamine (DEMA), and mixtures thereof. At 30.degree. C.-55.degree. C., which corresponds to typical fermentation temperatures, these low-molecular-weight amines or their mixtures, can extract large amounts of water from dilute aqueous solutions containing fermentation salts. Thus, dilute fermentation salt solutions can be concentrated by selectively removing water. At these low temperatures, the amine phase contains 20-35% water and a much reduced quantity of fermentation salt. When the temperature is raised, water phases out of the amine, allowing the amine to be recycled and reused to extract additional water. Using this approach, about 82.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: November 16, 1999
    Assignee: The Texas A&M University System
    Inventors: Mark T. Holtzapple, Richard R. Davison, Torsten Luettich
  • Patent number: 5969189
    Abstract: This invention provides a method for thermally converting volatile fatty acid (VFA) salts to ketones by mixing dry calcium salts of VFAs with hot heat transfer agent in an evacuated container, thereby causing thermal decomposition of the calcium salts of VFAs to form ketone-containing vapor and calcium carbonate; and separating the ketone-containing vapor from the calcium carbonate and heat transfer agent by condensing a mixture of ketones from the ketone-containing vapor.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: October 19, 1999
    Assignee: The Texas A&M University System
    Inventors: Mark T. Holtzapple, Richard R. Davison
  • Patent number: 5865898
    Abstract: The invention is directed to methods for the pretreatment of a lignocellulose-containing biomass. Pretreatment comprises the addition of calcium hydroxide and water to the biomass to form a mixture, and subjecting the mixture to relatively high temperatures for a period of time sufficient to render the biomass amenable to digestion. The pretreated biomass is digested to produce useful products such as feedstocks, fuels, and compounds including fatty acids, sugars, ketones and alcohols. Alternatively, the pretreatment process includes the addition of an oxidizing agent, selected from the group consisting of oxygen and oxygen-containing gasses, to the mixture under pressure. The invention is also directed to a method for the recovery of calcium from the pretreated biomass.
    Type: Grant
    Filed: July 27, 1993
    Date of Patent: February 2, 1999
    Assignee: The Texas A&M University System
    Inventors: Mark T. Holtzapple, Richard R. Davison
  • Patent number: 5693296
    Abstract: Lignocellulose-containing materials are treated with lime (calcium hydroxide) and water at a relatively high temperature and for a certain period of time under certain conditions. The process variables were: lime loading which ranged from about 2 to about g Ca(OH).sub.2 /100 g dry material; water loading which ranged from about 6 to about 19 g water/g dry material; treatment temperature which varied from about 50.degree. C. to about 150.degree. C.; and treatment time which varied from about 1 to about 36 hours. The effects of treatment time and temperature were interdependent.A process for lime recovery is developed. The soluble Ca(OH).sub.2 was washed out of the pretreated material with water and converted to insoluble CaCO.sub.3, by reacting with CO.sub.2, and was thus separated. The CaCO.sub.3 can be heated to produce CaO and CO.sub.2. The CaO is hydrated to Ca(OH).sub.2 which can be reused as the lignocellulose treatment agent. Carbon dioxide is reused for lime recovery.
    Type: Grant
    Filed: September 6, 1994
    Date of Patent: December 2, 1997
    Assignee: The Texas A&M University System
    Inventors: Mark T. Holtzapple, Richard R. Davison, Murlidhar Nagwani
  • Patent number: 5097677
    Abstract: A high efficiency evaporative intercooler/compressor assembly in which compressed refrigerant vapors are desuperheated by the introduction of a selected liquid refrigerant is disclosed. Additionally, the present invention relates to a method of introducing a refrigerant having a high latent heat of vaporization, such that the overall system efficiency is increased.
    Type: Grant
    Filed: September 20, 1989
    Date of Patent: March 24, 1992
    Assignee: Texas A&M University System
    Inventor: Mark T. Holtzapple
  • Patent number: 4825661
    Abstract: A high efficiency evaporator is disclosed. The evaporator is made with a ous wick on the interior of the evaporator housing to facilitate movement of a refrigerant liquid within the housing. This aids in dispersing the refrigerant.
    Type: Grant
    Filed: March 28, 1988
    Date of Patent: May 2, 1989
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Mark T. Holtzapple, Donald M. Ernst
  • Patent number: 4176522
    Abstract: A torque responsive apparatus for controlling a fluid actuated control device includes a first shaft connected to a drive motor and a second shaft connected to the first shaft through a coupling device that controls fluid pressure in a hydraulic control system whereby torque delivered to the coupling device effects shifting of the coupling member to vary the size of an opening through which a control fluid is being passed whereby a change in fluid pressure will result which is proportional to the torque of the first shaft.
    Type: Grant
    Filed: January 20, 1978
    Date of Patent: December 4, 1979
    Assignee: Mark Holtzapple
    Inventors: Mark T. Holtzapple, Robert L. Wehe, Charles G. Myer, William W. Carson