Patents by Inventor Pandurang V. Nikrad

Pandurang V. Nikrad 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: 8946114
    Abstract: A method of producing stable ferrous nitrate solution by dissolving iron in nitric acid to form a ferrous nitrate solution and maintaining the solution at a first temperature for a first time period, whereby the Fe(II) content of the ferrous nitrate solution changes by less than about 2% over a second time period. A method of producing stable Fe(II)/Fe(III) nitrate solution comprising ferrous nitrate and ferric nitrate and having a desired ratio of ferrous iron to ferric iron, including obtaining a stable ferrous nitrate solution; dissolving iron in nitric acid to form a ferric nitrate solution; maintaining the ferric nitrate solution at a second temperature for a third time period; and combining amounts of stable ferrous nitrate solution and ferric nitrate solution to produce the stable Fe(II)/Fe(III) nitrate solution. A method of preparing an iron catalyst is also described.
    Type: Grant
    Filed: May 29, 2009
    Date of Patent: February 3, 2015
    Assignee: Res USA, LLC.
    Inventors: Pandurang V. Nikrad, Jesse W. Taylor, Richard A. Bley, Danny M. Dubuisson, Sara L. Rolfe, Belma Demirel, Dawid J. Duvenhage, Harold A. Wright
  • Patent number: 8138115
    Abstract: A method of producing an iron catalyst for catalyzing the hydrogenation of carbon monoxide is disclosed. The method comprises using a reduced amount of acid for iron dissolution compared to certain previous methods. The resulting acidic iron mixture is heated without boiling to obtain a nitrate solution having a Fe2+:Fe3+ ratio in the range of about 0.01%:99.99% to about 100%:0% (wt:wt). Iron phases are precipitated at a lower temperature compared to certain previous methods. The recovered catalyst precursor is dried and sized to form particles having a size distribution between 10 microns and 100 microns. In embodiments, the Fe2+:Fe3+ ratio in the nitric acid solution may be in the range of from about 3%:97% to about 30%:70% (wt:wt) and the calcined catalyst may comprise a maghemite:hematite ratio of about 1%:99% to about 70%:30%.
    Type: Grant
    Filed: February 26, 2010
    Date of Patent: March 20, 2012
    Assignee: Rentech, Inc.
    Inventors: Belma Demirel, Charles B. Benham, Jesse W. Taylor, Pandurang V. Nikrad, Sara L. Rolfe, Olga P. Ionkina, Dawid J. Duvenhage, Harold A. Wright
  • Patent number: 7968611
    Abstract: A method of producing an iron catalyst for catalyzing the hydrogenation of carbon monoxide is disclosed. The method comprises using a reduced amount of acid for iron dissolution compared to certain previous methods. The resulting acidic iron mixture is heated without boiling to obtain a nitrate solution having a Fe2+:Fe3+ ratio in the range of about 0.01%: 99.99% to about 100%:0% (wt:wt). Iron phases are precipitated at a lower temperature compared to certain previous methods. The recovered catalyst precursor is dried and sized to form particles having a size distribution between 10 microns and 100 microns. In embodiments, the Fe2+:Fe3+ ratio in the nitric acid solution may be in the range of from about 3%:97% to about 30%:70% (wt:wt) and the calcined catalyst may comprise a maghemite:hematite ratio of about 1%:99% to about 70%:30%.
    Type: Grant
    Filed: February 26, 2010
    Date of Patent: June 28, 2011
    Assignee: Rentech, Inc.
    Inventors: Belma Demirel, Charles B. Benham, Jesse W. Taylor, Pandurang V. Nikrad, Sara L. Rolfe, Olga P. Ionkina, Dawid J. Duvenhage, Harold A. Wright
  • Patent number: 7879756
    Abstract: A method of producing an iron catalyst for catalyzing the hydrogenation of carbon monoxide is disclosed. The method comprises using a reduced amount of acid for iron dissolution compared to certain previous methods. The resulting acidic iron mixture is heated without boiling to obtain a nitrate solution having a Fe2+:Fe3+ ratio in the range of about 0.01%:99.99% to about 100%:0% (wt:wt). Iron phases are precipitated at a lower temperature compared to certain previous methods. The recovered catalyst precursor is dried and sized to form particles having a size distribution between 10 microns and 100 microns. In embodiments, the Fe2+:Fe3+ ratio in the nitric acid solution may be in the range of from about 3%:97% to about 30%:70% (wt:wt) and the calcined catalyst may comprise a maghemite:hematite ratio of about 1%:99% to about 70%:30%.
    Type: Grant
    Filed: August 11, 2008
    Date of Patent: February 1, 2011
    Assignee: Rentech, Inc.
    Inventors: Belma Demirel, Charles B. Benham, Jesse W. Taylor, Pandurang V. Nikrad, Sara L. Rolfe, Olga P. Ionkina, Dawid J. Duvenhage, Harold A. Wright
  • Publication number: 20100152307
    Abstract: A method of producing an iron catalyst for catalyzing the hydrogenation of carbon monoxide is disclosed. The method comprises using a reduced amount of acid for iron dissolution compared to certain previous methods. The resulting acidic iron mixture is heated without boiling to obtain a nitrate solution having a Fe2+:Fe3+ ratio in the range of about 0.01%:99.99% to about 100%:0% (wt:wt). Iron phases are precipitated at a lower temperature compared to certain previous methods. The recovered catalyst precursor is dried and sized to form particles having a size distribution between 10 microns and 100 microns. In embodiments, the Fe2+:Fe3+ ratio in the nitric acid solution may be in the range of from about 3%:97% to about 30%:70% (wt:wt) and the calcined catalyst may comprise a maghemite:hematite ratio of about 1%:99% to about 70%:30%.
    Type: Application
    Filed: February 26, 2010
    Publication date: June 17, 2010
    Applicant: RENTECH, INC.
    Inventors: Belma Demirel, Charles B. Benham, Jesse W. Taylor, Pandurang V. Nikrad, Sara L. Rolfe, Olga P. Ionkina, Dawid J. Duvenhage, Harold A. Wright
  • Publication number: 20100152036
    Abstract: A method of producing an iron catalyst for catalyzing the hydrogenation of carbon monoxide is disclosed. The method comprises using a reduced amount of acid for iron dissolution compared to certain previous methods. The resulting acidic iron mixture is heated without boiling to obtain a nitrate solution having a Fe2+:Fe3+ ratio in the range of about 0.01%:99.99% to about 100%:0% (wt:wt). Iron phases are precipitated at a lower temperature compared to certain previous methods. The recovered catalyst precursor is dried and sized to form particles having a size distribution between 10 microns and 100 microns. In embodiments, the Fe2+:Fe3+ ratio in the nitric acid solution may be in the range of from about 3%:97% to about 30%:70% (wt:wt) and the calcined catalyst may comprise a maghemite:hematite ratio of about 1%:99% to about 70%:30%.
    Type: Application
    Filed: February 26, 2010
    Publication date: June 17, 2010
    Applicant: RENTECH, INC.
    Inventors: Belma Demirel, Charles B. Benham, Jesse W. Taylor, Pandurang V. Nikrad, Sara L. Rolfe, Olga P. Ionkina, Dawid J. Duvenhage, Harold A. Wright
  • Publication number: 20090298681
    Abstract: A method of producing stable ferrous nitrate solution by dissolving iron in nitric acid to form a ferrous nitrate solution and maintaining the solution at a first temperature for a first time period, whereby the Fe(II) content of the ferrous nitrate solution changes by less than about 2% over a second time period. A method of producing stable Fe(II)/Fe(III) nitrate solution comprising ferrous nitrate and ferric nitrate and having a desired ratio of ferrous iron to ferric iron, including obtaining a stable ferrous nitrate solution; dissolving iron in nitric acid to form a ferric nitrate solution; maintaining the ferric nitrate solution at a second temperature for a third time period; and combining amounts of stable ferrous nitrate solution and ferric nitrate solution to produce the stable Fe(II)/Fe(III) nitrate solution. A method of preparing an iron catalyst is also described.
    Type: Application
    Filed: May 29, 2009
    Publication date: December 3, 2009
    Applicant: RENTECH, INC.
    Inventors: Pandurang V. Nikrad, Jesse W. Taylor, Richard A. Bley, Danny M. Dubuisson, Sara L. Rolfe, Belma Demirel, Dawid J. Duvenhage, Harold A. Wright
  • Publication number: 20090298678
    Abstract: A method of producing a catalyst precursor comprising iron phases by co-feeding a ferrous nitrate solution and a precipitation agent into a ferric nitrate solution to produce a precipitation solution having a desired ferrous:ferric nitrate ratio and from which catalyst precursor precipitates; co-feeding a ferric nitrate solution and a precipitation agent into a ferrous nitrate solution to produce a precipitation solution having a desired ferrous:ferric nitrate ratio and from which catalyst precursor precipitates; or precipitating a ferrous precipitate from a ferrous nitrate solution by contacting the ferrous nitrate solution with a first precipitation agent; precipitating a ferric precipitate from ferric nitrate solution by contacting the ferric nitrate solution with a second precipitation agent and combining the ferrous and ferric precipitates to form the catalyst precursor, wherein the ratio of ferrous:ferric precipitates is a desired ratio.
    Type: Application
    Filed: May 29, 2009
    Publication date: December 3, 2009
    Applicant: RENTECH, INC.
    Inventors: Belma DEMIREL, Jesse W. TAYLOR, Pandurang V. NIKRAD, Sara L. ROLFE, Dawid J. DUVENHAGE, Harold A. WRIGHT
  • Publication number: 20090069451
    Abstract: A method of producing an iron catalyst for catalyzing the hydrogenation of carbon monoxide is disclosed. The method comprises using a reduced amount of acid for iron dissolution compared to certain previous methods. The resulting acidic iron mixture is heated without boiling to obtain a nitrate solution having a Fe2+:Fe3+ ratio in the range of about 0.01%:99.99% to about 100%:0% (wt:wt). Iron phases are precipitated at a lower temperature compared to certain previous methods. The recovered catalyst precursor is dried and sized to form particles having a size distribution between 10 microns and 100 microns. In embodiments, the Fe2+:Fe3+ ratio in the nitric acid solution may be in the range of from about 3%:97% to about 30%:70% (wt:wt) and the calcined catalyst may comprise a maghemite:hematite ratio of about 1%:99% to about 70%:30%.
    Type: Application
    Filed: August 11, 2008
    Publication date: March 12, 2009
    Applicant: RENTECH, INC.
    Inventors: Belma Demirel, Charles B. Benham, Jesse W. Taylor, Pandurang V. Nikrad, Sara L. Rolfe, Olga P. Ionkina, Dawid J. Duvenhage, Harold A. Wright
  • Patent number: 5939290
    Abstract: The present invention is drawn to methods for the synthesis of sialyl Lewis.sup.x derivatives modified at the C-2 and/or C-6 position of GlcNAc employing chemoenzymatic synthesis. The derivatives find use in the treatment and prevention of diseases.
    Type: Grant
    Filed: May 19, 1995
    Date of Patent: August 17, 1999
    Assignee: Alberta Research Council
    Inventors: Andre P. Venot, Pandurang V. Nikrad, Mohammed A. Kashem
  • Patent number: 5882901
    Abstract: The present invention is drawn to methods for the synthesis of Lewis.sup.a derivatives modified at the C-2 and/or C-6 position of GlcNAc employing chemo-enzymatic synthesis. The derivatives find use in the treatment and prevention of diseases.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: March 16, 1999
    Assignee: Alberta Research Council
    Inventors: Andre P. Venot, Pandurang V. Nikrad, Mohammed A. Kashem
  • Patent number: 5872096
    Abstract: The present invention is drawn to methods for the synthesis of Lewis.sup.a derivatives modified at the C-2 and/or C-6 position of GlcNAc employing chemo-enzymatic synthesis. The derivatives find use in the treatment and prevention of diseases.
    Type: Grant
    Filed: October 20, 1994
    Date of Patent: February 16, 1999
    Assignee: Alberta Research Council
    Inventors: Andre P. Venot, Pandurang V. Nikrad, Mohammed A. Kashem
  • Patent number: 5759993
    Abstract: The present invention is drawn to methods for the synthesis of sialyl Lewis.sup.x derivatives modified at the C-2 and/or C-6 position of GlcNAc employing chemo-enzymatic synthesis. The derivatives find use in the treatment and prevention of diseases.
    Type: Grant
    Filed: October 20, 1994
    Date of Patent: June 2, 1998
    Assignee: Alberta Research Council
    Inventors: Andre P. Venot, Pandurang V. Nikrad, Mohammed A. Kashem
  • Patent number: 5646123
    Abstract: Disclosed are methods for reducing the degree of antigen induced inflammation in a sensitized mammals. The disclosed methods employ oligosaccharide glycosides related to blood group determinants having a type I or type II core structure wherein the administration of such oligosaccharide glycosides is after initiation of the mammal's immune response but at or prior one-half the period of time required to effect maximal antigen-induced inflammation.
    Type: Grant
    Filed: March 17, 1995
    Date of Patent: July 8, 1997
    Assignee: Alberta Research Council
    Inventors: Robert M. Ippolito, Wasimul Haque, Cong Jiang, H. Rizk Hanna, Andre P. Venot, Pandurang V. Nikrad, Mohammed A. Kashem, Richard Smith, Om P. Srivastava
  • Patent number: 5580858
    Abstract: Disclosed are novel Lewis.sup.x and Lewis.sup.a analogues, pharmaceutical compositions containing such analogues, methods for their preparation and methods for their use.
    Type: Grant
    Filed: November 4, 1994
    Date of Patent: December 3, 1996
    Assignee: Alberta Research Council
    Inventors: Robert M. Ippolito, Wasimul Haque, Cong Jiang, H. Rizk Hanna, Andre P. Venot, Pandurang V. Nikrad, Mohammed A. Kashem, Richard H. Smith