Patents by Inventor Rangasamy Pitchai

Rangasamy Pitchai 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: 6194591
    Abstract: An olefin epoxidation process is described. The process comprises epoxidizing an olefin with hydrogen peroxide in the presence of a modified titanium zeolite catalyst in water solvent. The titanium zeolite catalyst is modified with a platinum, palladium or copper compound. The modified catalyst unexpectedly increases olefin epoxidation activity.
    Type: Grant
    Filed: April 27, 2000
    Date of Patent: February 27, 2001
    Assignee: ARCO Chemical Technology, L.P.
    Inventors: Roger A. Grey, Rangasamy Pitchai
  • Patent number: 6083870
    Abstract: Propylene is oxidized to propylene oxide in the vapor phase using an oxygen-containing gas and a supported silver catalyst comprising silver and a support comprised in whole or in substantial part of certain alkaline earth metal compounds. The alkaline earth metal compound may, for example, be a calcium compound such as calcium titanate, tribasic calcium phosphate, calcium molybdate, or calcium fluoride, a magnesium compound such as magnesium aluminate, or a strontium compound such as strontium titanate. Such supports provide significantly higher selectivity to the desired epoxide than would be expected from the performance of related materials. Propylene oxide selectivity may be further enhanced through the introduction of nitrogen oxide species such as NO, alkyl halides such as ethyl chloride, and carbon dioxide into the oxygen-containing gas.
    Type: Grant
    Filed: March 10, 1998
    Date of Patent: July 4, 2000
    Assignee: ARCO Chemical Technology, L.P.
    Inventors: Andrew P. Kahn, Anne M. Gaffney, Rangasamy Pitchai
  • Patent number: 5973171
    Abstract: An integrated process is provided for the production of propylene oxide from propane wherein propane is dehydrogenated to propylene and hydrogen and the resulting propylene, propane, and hydrogen mixture together with added oxygen is reacted over a palladium on titanium silicilite catalyst to form propylene oxide, the molar ratio of oxygen to hydrogen in the reaction feed being at least about 2/1.
    Type: Grant
    Filed: October 7, 1998
    Date of Patent: October 26, 1999
    Assignee: ARCO Chemical Technology, LP
    Inventors: Robert N. Cochran, John C. Jubin, Jr., Mark A. Liepa, Robert Nedwick, Rangasamy Pitchai, W. Wayne Wentzheimer
  • Patent number: 5874652
    Abstract: A process for hydrogenating aqueous mixtures of 4-hydroxybutanal and 3-hydroxy-2-methylpropanal is disclosed. The process uses a metallic Pt--Ru catalyst supported on .gamma.-alumina. The process gives improved yields of 2-methyl-1,3-propanediol while minimizing the formation of unwanted by-products such as isobutyl alcohol and tetrahydrofuran.
    Type: Grant
    Filed: October 18, 1993
    Date of Patent: February 23, 1999
    Assignee: Arco Chemical Technology, L.P.
    Inventors: Rangasamy Pitchai, Thomas S. Zak
  • Patent number: 5770746
    Abstract: A propylene epoxidation process wherein a supported silver catalyst is utilized may be operated at high efficiency even in the absence of any organic chloride in the feedstream, provided the catalyst is first contacted at an elevated temperature with a treatment stream comprised of an organic chloride and molecular oxygen.
    Type: Grant
    Filed: June 23, 1997
    Date of Patent: June 23, 1998
    Assignee: Arco Chemical Technology, L.P.
    Inventors: Bernard Cooker, Anne M. Gaffney, Jennifer D. Jewson, Andrew P. Kahn, Rangasamy Pitchai
  • Patent number: 5763630
    Abstract: Propylene is oxidized to propylene oxide in the vapor phase using an oxygen-containing gas and a supported silver catalyst comprising silver and a support comprised in whole or in substantial part of certain alkaline earth metal compounds. The alkaline earth metal compound may, for example, be a calcium compound such as calcium titanate, tribasic calcium phosphate, calcium molybdate, or calcium fluoride, a magnesium compound such as magnesium aluminate, or a strontium compound such as strontium titanate. Such supports provide significantly higher selectivity to the desired epoxide than would be expected from the performance of related materials. Propylene oxide selectivity may be further enhanced through the introduction of nitrogen oxide species such as NO, alkyl halides such as ethyl chloride, and carbon dioxide into the oxygen-containing gas.
    Type: Grant
    Filed: March 18, 1996
    Date of Patent: June 9, 1998
    Assignee: ARCO Chemical Technology, L.P.
    Inventors: Andrew P. Kahn, Anne M. Gaffney, Rangasamy Pitchai
  • Patent number: 5703254
    Abstract: Propylene is oxidized to propylene oxide in the vapor phase using oxygen and a supported catalyst comprising silver, gold, a potassium promoter such as potassium nitrate or potassium carbonate and a support comprised in whole or in substantial part of an alkaline earth metal carbonate.
    Type: Grant
    Filed: October 2, 1996
    Date of Patent: December 30, 1997
    Assignee: Arco Chemical Technology, L.P.
    Inventors: Anne M. Gaffney, Andrew P. Kahn, Rangasamy Pitchai
  • Patent number: 5698719
    Abstract: Oxirane compounds are formed by vapor phase catalytic molecular oxygen oxidation of a C.sub.3 -C.sub.10 olefin using a silver catalyst, and the selectivity to the oxirane product is enhanced by preconditioning the catalyst by contact with the olefin at elevated temperature in the absence of oxygen; oxygen is periodically pulsed to the reaction.
    Type: Grant
    Filed: October 11, 1996
    Date of Patent: December 16, 1997
    Assignee: Arco Chemical Tehnology, L.P.
    Inventors: Anne M. Gaffney, C. Andrew Jones, Rangasamy Pitchai, Andrew P. Kahn
  • Patent number: 5686380
    Abstract: Propylene is converted to propylene oxide in a vapor phase oxidation process employing a silver catalyst supported on an alkaline earth metal carbonate and containing both a potassium salt such as potassium nitrate and a molybdenum promoter. The potassium salt and the molybdenum promoter may be simultaneously supplied by the use of a potassium salt of a molybdenum oxyanion. The efficiency of the process is greatly enhanced through the simultaneous inclusion of carbon dioxide and an organic halide in the feedstream. The feedstream need not contain a nitrogen oxide species such as NO to attain high propylene oxide selectivity.
    Type: Grant
    Filed: October 28, 1996
    Date of Patent: November 11, 1997
    Assignee: ARCO Chemical Technology, L.P.
    Inventors: Rangasamy Pitchai, Andrew P. Kahn, Anne M. Gaffney
  • Patent number: 5625084
    Abstract: Propylene is converted to propylene oxide in a vapor phase oxidation process employing a silver catalyst supported on an alkaline earth metal carbonate and containing both a potassium salt such as potassium nitrate and a molybdenum promoter. The potassium salt and the molybdenum promoter may be simultaneously supplied by the use of a potassium salt of a molybdenum oxyanion. The efficiency of the process is greatly enhanced through the simultaneous inclusion of carbon dioxide and an organic halide in the feedstream. The feedstream need not contain a nitrogen oxide species such as NO to attain high propylene oxide selectivity.
    Type: Grant
    Filed: January 31, 1996
    Date of Patent: April 29, 1997
    Assignee: ARCO Chemical Technology, L.P.
    Inventors: Rangasamy Pitchai, Andrew P. Kahn, Anne M. Gaffney
  • Patent number: 5319114
    Abstract: Olefins are selectively converted to epoxides by reacting with an organic hydroperoxide in the presence of a heterogeneous catalyst comprised of a carbon molecular sieve containing a Group IVA, VA, VIA, or VIIA transition metal such as molybdenum.
    Type: Grant
    Filed: September 23, 1993
    Date of Patent: June 7, 1994
    Assignee: Arco Chemical Technology, L. P.
    Inventors: Anne M. Gaffney, Manish K. Nandi, Rangasamy Pitchai, Yuan-Zhang Han
  • Patent number: 5276210
    Abstract: An improved allyl alcohol hydroformylation process and catalyst are disclosed. The process uses a catalyst system comprising a Group VIII metal carbonyl complex catalyst, a trisubstituted phosphine, a neutral Group VIII(a) metal complex cocatalyst, and optionally, a diphosphinoalkane. The process uniquely gives an enhanced linear:branched aldehyde product ratio.
    Type: Grant
    Filed: March 29, 1993
    Date of Patent: January 4, 1994
    Assignee: ARCO Chemical Technology, L.P.
    Inventors: Rangasamy Pitchai, Anne M. Gaffney, Manish K. Nandi, Yuan-Zhang Han
  • Patent number: 5233093
    Abstract: An improved allyl alcohol hydroformylation process and catalyst are disclosed. The process uses a catalyst system comprising a Group VIII metal carbonyl complex catalyst, a trisubstituted phosphine, a neutral Group VIII(a) metal complex cocatalyst, and optionally, a diphosphinoalkane. The process uniquely gives an enhanced linear:branched aldehyde product ratio.
    Type: Grant
    Filed: July 20, 1992
    Date of Patent: August 3, 1993
    Assignee: ARCO Chemical Technology, L.P.
    Inventors: Rangasamy Pitchai, Anne M. Gaffney, Manish K. Nandi, Yuan-Zhang Han
  • Patent number: 5221464
    Abstract: Supports for catalytic reforming catalysts are prepared by doping ZrO.sub.2 with tantalum. The catalyst may contain a Group VII or Group VIII metal and/or an acidic component.
    Type: Grant
    Filed: August 12, 1991
    Date of Patent: June 22, 1993
    Assignee: Sun Company, Inc. (R&M)
    Inventors: Vincent A. Durante, Aristides Macris, Rangasamy Pitchai, Xenophon E. Verykios
  • Patent number: 5208194
    Abstract: A process for recovering a Group VIII metal from an organic solution is disclosed. The organic solution is contacted with an acidic ion exchange resin that has sulfonic acid active groups. The invention provides an effective and economical way to recover valuable transition metals from dilute organic solutions.
    Type: Grant
    Filed: February 25, 1992
    Date of Patent: May 4, 1993
    Assignee: Arco Chemical Technology, L.P.
    Inventors: Rangasamy Pitchai, Thomas S. Zak, Kurt E. Soring
  • Patent number: 5208385
    Abstract: A process for producing tetrahydrofuran polymers having a narrow molecular weight distribution is disclosed. Tetrahydrofuran is polymerized in the presence of a carboxylic acid anhydride and amorphous silica-alumina. The process overcomes the need for costly post-treatment techniques such as distillation and selective solvent extraction.
    Type: Grant
    Filed: February 19, 1992
    Date of Patent: May 4, 1993
    Assignee: Arco Chemical Technology, L.P.
    Inventors: Andrew P. Kahn, Robert G. Gastinger, Rangasamy Pitchai
  • Patent number: 5166370
    Abstract: A process for producing tetrahydrofuran, 1,4-butanediol, and 2-methyl-1,3,-propanediol is disclosed. A mixture containing 4-hydroxybutanal and 3-hydroxy-2-methylpropanal is hydrogenated in the presence of a transition metal supported on a weakly acidic ion-exchange resin or zeolite-type material to give tetrahydrofuran as the major product, and 1,4-butanediol and 2-methyl-1,3-propanediol as minor products. High yields of 2-methyl-1,3-propanediol can be obtained.
    Type: Grant
    Filed: April 12, 1991
    Date of Patent: November 24, 1992
    Assignee: Arco Chemical Technology, L.P.
    Inventors: Frank J. Liotta, Jr., Haven S. Kesling, Jr., Rangasamy Pitchai