Patents by Inventor Douglas K. Stephens

Douglas K. Stephens 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: 6638354
    Abstract: Disclosed are amorphous precipitated silicas, silica gels, and amorphous carbons derived from biomass and methods of producing them with and without adhered or deposited amorphous carbons produced by acidifying a caustic silicate solution produced by caustic digestion of biomass ash containing silica with and without activated carbon, the ash being obtained from thermal pyrolysis of the biomass, the acidifying effective to produce a slurry of the precipitated silica and silica gels with and without adhered or deposited amorphous carbon, and separated from the slurry the precipitated silicas and silica gels with and without the adhered or deposited amorphous carbons. The properties of the precipitated silica with adhered or deposited carbon being within the range as utilized in rubber compositions thereby avoiding the blending of silica and carbon components for such use.
    Type: Grant
    Filed: January 30, 2002
    Date of Patent: October 28, 2003
    Assignees: Agritec, Inc., Occidental Chemical Corporation
    Inventors: Douglas K. Stephens, Clyde W. Wellen, Jeffrey B. Smith, Kenneth F. Kubiak
  • Publication number: 20030097966
    Abstract: Disclosed are amorphous precipitated silicas, silica gels, and amorphous carbons derived from biomass and methods of producing them with and without adhered or deposited amorphous carbons produced by acidifying a caustic silicate solution produced by caustic digestion of biomass ash containing silica with and without activated carbon, the ash being obtained from thermal pyrolysis of the biomass, the acidifying effective to produce a slurry of the precipitated silica and silica gels with and without adhered or deposited amorphous carbon, and separated from the slurry the precipitated silicas and silica gels with and without the adhered or deposited amorphous carbons. The properties of the precipitated silica with adhered or deposited carbon being within the range as utilized in rubber compositions thereby avoiding the blending of silica and carbon components for such use.
    Type: Application
    Filed: January 30, 2002
    Publication date: May 29, 2003
    Applicant: Agritec, Inc.
    Inventors: Douglas K. Stephens, Clyde W. Wellen, Jeffrey B. Smith, Kenneth F. Kubiak
  • Patent number: 6409817
    Abstract: Disclosed is a rigid fine-celled light-weight foam composition and a method of producing it which has improved retention of liquids by absorption/adsorption which improves the thermal insulation and fire retardant properties of the fine-celled foam particularly suited for use in double walled tanks and hollow canopies, building panels, profiles, and the like.
    Type: Grant
    Filed: May 8, 2000
    Date of Patent: June 25, 2002
    Assignee: Agritec, Inc.
    Inventor: Douglas K. Stephens
  • Patent number: 6375735
    Abstract: Disclosed are amorphous precipitated silicas, silica gels, and amorphous carbons derived from biomass and methods of producing them with and without adhered or deposited amorphous carbons produced by acidifying a caustic silicate solution produced by caustic digestion of biomass ash containing silica with and without activated carbon, the ash being obtained from thermal pyrolysis of the biomass, the acidifying effective to produce a slurry of the precipitated silica and silica gels with and without adhered or deposited amorphous carbon, and separated from the slurry the precipitated silicas and silica gels with and without the adhered or deposited amorphous carbons. The properties of the precipitated silica with adhered or deposited carbon being within the range as utilized in rubber compositions thereby avoiding the blending of silica and carbon components for such use.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: April 23, 2002
    Assignees: Agritec, Inc., Occidental Chemical Corporation
    Inventors: Douglas K. Stephens, Clyde W. Wellen, Jeffrey B. Smith, Kenneth F. Kubiak
  • Patent number: 6114280
    Abstract: Disclosed are highly activated carbon particles derived from caustic digestion of rice hull ash obtained from thermal pyrolysis of rice hulls having an iodine number of at least 650 to 1000. The activated carbon pores are free of silicate residue from the caustic digestion. Also disclosed are methods of removing the silicate residue from the caustic silicate solution during digestion effective to substantially improve the activation of the carbon particles to commercial grade.
    Type: Grant
    Filed: September 23, 1998
    Date of Patent: September 5, 2000
    Assignee: Agritec, Inc.
    Inventor: Douglas K. Stephens
  • Patent number: 5858911
    Abstract: Disclosed is a rigid fine-celled foam composition and a method of producing it. The foam composition is nontoxic, environmentally friendly, has improved absorption/adsorption and retention of liquids, is not as hard as prior art foams, does not include polymerization by-products detrimental to flower and plant life, and is a foamed mixture of a caustic silicate solution derived from the caustic digestion of rice hull ash having diffused activated carbon particles from thermal pyrolysis of rice hulls rather than from commercial sodium silicate solutions. Valuable by-products of commodity grade are obtained including activated carbon and sodium fluoride.
    Type: Grant
    Filed: November 24, 1997
    Date of Patent: January 12, 1999
    Assignee: Agritec, Inc.
    Inventors: Clyde W. Wellen, Douglas K. Stephens, Greg R. Wellen
  • Patent number: 5714000
    Abstract: Disclosed is a rigid fine-celled foam composition and a method of producing it. The foam composition is nontoxic, environmentally friendly, has improved absorption/adsorption and retention of liquids, is not as hard as prior art foams, does not include polymerization by-products detrimental to flower and plant life, and is a foamed mixture of a caustic silicate solution derived from the caustic digestion of rice hull ash having diffused activated carbon particles from thermal pyrolysis of rice hulls rather than from commercial sodium silicate solutions. Valuable by-products of commodity grade are obtained including activated carbon and sodium fluoride.
    Type: Grant
    Filed: July 10, 1996
    Date of Patent: February 3, 1998
    Assignee: Agritec, Inc.
    Inventors: Clyde W. Wellen, Douglas K. Stephens, Greg R. Wellen