Patents by Inventor Tilak P. Wijesekera

Tilak P. Wijesekera 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: 7034192
    Abstract: A method is provided for the efficient, low cost removal of acetol from a phenol stream. The method results in removal of substantially all of the acetol from the phenol stream without the formation of substantial amounts of additional methylbenzofuran. The method also avoids the use of expensive reagents and capital intensive distillation equipment.
    Type: Grant
    Filed: August 9, 2004
    Date of Patent: April 25, 2006
    Assignee: Sunoco Inc. (R&M)
    Inventor: Tilak P. Wijesekera
  • Patent number: 7002048
    Abstract: A method is provided for the efficient, low cost removal of acetol from a phenol stream. The method results in removal of substantially all of the acetol from the phenol stream without the formation of substantial amounts of additional methylbenzofuran. The method also avoids the use of expensive reagents and capital intensive distillation equipment.
    Type: Grant
    Filed: September 16, 2004
    Date of Patent: February 21, 2006
    Assignee: Sunoco, Inc. (R&M)
    Inventors: Tilak P. Wijesekera, Manoj V. Bhinde
  • Patent number: 6388144
    Abstract: A process for treating phenol with a strong acid ion exchange resin to reduce the level of methylbenzofuran is provided. The process is capable of being carried out at elevated temperatures for extended periods, such that cooling of the phenol from distillation temperatures prior to the resin treatment is not required. The process can reduce or eliminate the substantial costs associated with conventional processes that require cooling and re-heating the phenol.
    Type: Grant
    Filed: June 15, 2001
    Date of Patent: May 14, 2002
    Assignee: Sunoco, Inc. (R&M)
    Inventors: Tilak P. Wijesekera, Scott R. Keenan
  • Patent number: 6169202
    Abstract: Alkanes are converted to unsaturated carboxylic acids by contacting an alkane with an oxidizing agent and a Wells-Dawson type heteropolyacid supported on wide pore polyoxometallate salts.
    Type: Grant
    Filed: March 14, 2000
    Date of Patent: January 2, 2001
    Assignees: Sunoco, Inc. (R&M), Rohm and Haas Company
    Inventors: Tilak P. Wijesekera, James E. Lyons, Paul E. Ellis, Jr.
  • Patent number: 6060419
    Abstract: Alkanes are converted to unsaturated carboxylic acids by contacting an alkane with an oxidizing agent and a Wells-Dawson type heteropolyacid supported on wide pore polyoxometallate salts.
    Type: Grant
    Filed: August 14, 1998
    Date of Patent: May 9, 2000
    Assignees: Sunoco, Inc. (R&M), Rohm and Haas Company
    Inventors: Tilak P. Wijesekera, James E. Lyons, Paul E. Ellis, Jr.
  • Patent number: 5981424
    Abstract: Catalyst compositions are disclosed which are useful for the hydroxylation and the ammination of aromatic hydrocarbons using molecular oxygen as terminal oxidant. The catalysts comprise a support selected from the group consisting of metal oxides, molecular sieves, zeolites and clays; transition metal selected from the group consisting of vanadium, niobium, copper, palladium, nickel and silver, and combinations thereof; and at least one multidentate chelating, binucleating ligand. The catalysts may further comprise additional metal ions. The process is particularly suited, for example, to the one-step conversion of benzene to phenol and of benzene to aniline.
    Type: Grant
    Filed: July 31, 1997
    Date of Patent: November 9, 1999
    Assignee: Sunoco, Inc. (R&M)
    Inventors: Vincent A. Durante, Tilak P. Wijesekera, Swati Karmakar
  • Patent number: 5962752
    Abstract: A process is disclosed for the catalytic hydroxylation of aromatic hydrocarbons which comprises contacting aromatic feedstock with oxidant comprising molecular oxygen, under suitable reaction conditions, in the presence of a catalyst comprising vanadyl (V.sup.IV) on an alumina support, preferably on leached alumina. The process is particularly suited, for example, to the one-step conversion of benzene to phenol.
    Type: Grant
    Filed: July 31, 1997
    Date of Patent: October 5, 1999
    Assignee: Sun Company, Inc.
    Inventors: Vincent A. Durante, Tilak P. Wijesekera, Swati Karmakar
  • Patent number: 5952532
    Abstract: A process is disclosed for the catalytic hydroxylation of aromatic hydrocarbons which comprises contacting aromatic feedstock with oxidant comprising molecular oxygen, under suitable reaction conditions, in the presence of a catalyst comprising three essential components: a support; transition metal selected from the group consisting of vanadium, niobium, copper, palladium, nickel and silver, or combinations thereof, and a promoter comprising a multidentate chelating, binucleating ligand. The catalysts may further comprise additional metal ions. The process is particularly suited, for example, to the one-step conversion of benzene to phenol.
    Type: Grant
    Filed: July 31, 1997
    Date of Patent: September 14, 1999
    Assignee: Sunoco, Inc.
    Inventors: Vincent A. Durante, Tilak P. Wijesekera, Swati Karmakar
  • Patent number: 5861536
    Abstract: The present invention comprises a process for catalytic oxidative ammination of aromatic hydrocarbons which comprising contacting aromatic feedstock with oxidant, such as molecular oxygen, under suitable reaction conditions, in the presence of a catalyst comprising three essential components: a support; transition metal; and a mono- or binucleating ligand. In one embodiment of the invention the ligand comprises at least one nitro or nitroso group. In another embodiment, the ligand comprises a multidentate, chelating binuclear compound. The process is particularly suited, for example, to the one-step conversion of benzene to aniline.
    Type: Grant
    Filed: July 31, 1997
    Date of Patent: January 19, 1999
    Assignee: Sun Company, Inc. (R&M)
    Inventors: Vincent A. Durante, Tilak P. Wijesekera, Swati Karmakar
  • Patent number: 5241062
    Abstract: The hydroxyl group in a pyrrolic compound having in the 2-position thereof a group having the formula R(OH)CH--R is hydrocarbyl or substituted hydrocarbyl, is replaced by a group, for example a p-nitrobenzoate group, having better leaving properties than those of hydroxyl for a subsequent self-condensation and cyclization of the pyrrolic compound to form a meso-hydrocarbyl or meso-substituted hydrocarbyl porphyrin.
    Type: Grant
    Filed: January 19, 1993
    Date of Patent: August 31, 1993
    Assignee: Sun Company, Inc. (R&M)
    Inventors: Tilak P. Wijesekera, Richard W. Wagner
  • Patent number: 5077394
    Abstract: Disclosed are tetraphenyl porphyrins which are beta-substituted by fluoro or chloro and/or bear electronegative substituents on the phenyl including one or two water solubilizing substituents. The new porphorins are particularly suitable as catalysts in a variety of oxidative reactions and methods.
    Type: Grant
    Filed: December 21, 1989
    Date of Patent: December 31, 1991
    Assignee: Sandoz Ltd.
    Inventors: David H. Dolphin, Taku Nakano, Thomas K. Kirk, Tilak P. Wijesekera, Roberta L. Farrell, Theodore E. Maione
  • Patent number: 4892941
    Abstract: Disclosed are tetraphenyl porphyrins which are beta-substituted by fluoro or chloro and/or bear electronegative substituents on the phenyl including one or two water solubilizing substituents. The new porphorins are particularly suitable as catalysts in a variety of oxidative reactions and methods.
    Type: Grant
    Filed: April 15, 1988
    Date of Patent: January 9, 1990
    Inventors: David H. Dolphin, Taku Nakano, Thomas K. Kirk, Tilak P. Wijesekera, Roberta L. Farrell, Theodore E. Maione