Patents by Inventor Darbha Srinivas

Darbha Srinivas 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).

  • Publication number: 20240101506
    Abstract: The present invention discloses a continuous process for the synthesis of dimethyl carbonate from methanol and carbon dioxide over a ceria-based mixed metal oxide-silica catalyst formulation in the presence of a dehydrating or water trapping compound (2-Cyanopyridine).
    Type: Application
    Filed: January 25, 2022
    Publication date: March 28, 2024
    Inventors: Darbha SRINIVAS, Vijay Vasant BOKADE, Prashant Suresh NIPHADKAR, Unnikrishnan PULIKKEEL, Snehalkumar PARMAR, Vinay AMTE, Surajit SENGUPTA, Asit Kumar DAS
  • Patent number: 9334361
    Abstract: Process for preparing hyperbranched polyesters at atmospheric pressure by reacting polyols with polycarboxylic acid in the presence of a heterogeneous, reusable, acid, crystalline, micro-mesoporous double-metal cyanide catalyst Zn3M2(CN)n(ROH).xZnCl2.yH2O at moderate temperatures for a short period of reaction time. Examples of a polyol include glycerol, sorbitol, mannitol, glucose and sucrose. Examples of a polycarboxylic acid include succinic acid and adipic acid. The hyper-branched polyester produced has a high degree of branching (56-90%), a low viscosity (inherent viscosity 0.02-0.1 dL/g), and a controlled gelation.
    Type: Grant
    Filed: February 23, 2012
    Date of Patent: May 10, 2016
    Assignee: Council of Scientific & Industrial Research
    Inventors: Darbha Srinivas, Joby Sebastian
  • Patent number: 9221749
    Abstract: An efficient and eco-friendly process for producing amide compounds comprising contacting a primary amine with molecular oxygen-containing gas, solvent and ammonia solution in the presence of a non-precious metal-containing ordered, mesoporous solid catalyst is disclosed.
    Type: Grant
    Filed: March 4, 2013
    Date of Patent: December 29, 2015
    Assignee: Council of Scientific & Industrial Research
    Inventors: Darbha Srinivas, Anuj Kumar, Nepak Devadutta
  • Patent number: 9174919
    Abstract: The invention discloses an improved process for preparing fatty acid esters with 100 mol % selectivity suitable as biodegradable lubricant base oils, comprising contacting a fatty compound with an alcohol in presence of a solid, phosphonate catalyst having molecular formula: M(X)2-nYn.mH2O where X refers to phenyl phosphonate, Y refers to HPO42? or HPO32?, M refers to a metal or metalloid ion preferably taken from the group consisting of Zr, Zn, Cd, Al, Sn, La and Ce, the value of n varies from 0.2 to 1.8 and the value of m varies from 0 to 5, wherein the fatty compound is a fatty acid or fatty acid methyl or ethyl ester or vegetable oil or animal fat or their mixture thereof and alcohol is a monohydric alcohol with 6 to 22 carbon atoms or a polyol with at least two hydroxyl groups.
    Type: Grant
    Filed: May 22, 2013
    Date of Patent: November 3, 2015
    Assignee: Council of Scientific and Industrial Research
    Inventors: Darbha Srinivas, Mehejabeen Kotwal
  • Patent number: 9073849
    Abstract: An eco-friendly process for making dimethyl carbonate comprising contacting methanol with carbon dioxide in the presence of a solid, calcined catalyst derived from zirconium phosphonate catalyst having molecular formula: Zr(X)2-nYn.mH2O where X refers to phosphonate, Y refers to HPO42? or HPO32?, n varies from 0.2 to 1.8 and m varies from 0 to 5, is disclosed.
    Type: Grant
    Filed: May 22, 2013
    Date of Patent: July 7, 2015
    Assignee: COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH
    Inventors: Darbha Srinivas, Unnikrishnan Pulikkeel
  • Publication number: 20150148554
    Abstract: The invention discloses an improved process for preparing fatty acid esters with 100 mol % selectivity suitable as biodegradable lubricant base oils, comprising contacting a fatty compound with an alcohol in presence of a solid, phosphonate catalyst having molecular formula: M(X)2-nYn.mH2O where X refers to phenyl phosphonate, Y refers to HPO42? or HPO32?, M refers to a metal or metalloid ion preferably taken from the group consisting of Zr, Zn, Cd, Al, Sn, La and Ce, the value of n varies from 0.2 to 1.8 and the value of m varies from 0 to 5, wherein the fatty compound is a fatty acid or fatty acid methyl or ethyl ester or vegetable oil or animal fat or their mixture thereof and alcohol is a monohydric alcohol with 6 to 22 carbon atoms or a polyol with at least two hydroxyl groups.
    Type: Application
    Filed: May 22, 2013
    Publication date: May 28, 2015
    Inventors: Darbha Srinivas, Mehejabeen Kotwal
  • Publication number: 20150141690
    Abstract: An eco-friendly process for making dimethyl carbonate comprising contacting methanol with carbon dioxide in the presence of a solid, calcined catalyst derived from zirconium phosphonate catalyst having molecular formula: Zr(X)2-nYn.mH2O where X refers to phosphonate, Y refers to HPO42? or HPO32?, n varies from 0.2 to 1.8 and m varies from 0 to 5, is disclosed.
    Type: Application
    Filed: May 22, 2013
    Publication date: May 21, 2015
    Applicant: COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH
    Inventors: Darbha Srinivas, Unnikrishnan Pulikkeel
  • Publication number: 20150099900
    Abstract: An efficient and eco-friendly process for producing amide compounds comprising contacting a primary amine with molecular oxygen-containing gas, solvent and ammonia solution in the presence of a non-precious metal-containing ordered, mesoporous solid catalyst is disclosed.
    Type: Application
    Filed: March 4, 2013
    Publication date: April 9, 2015
    Applicant: COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH
    Inventors: Darbha Srinivas, Anuj Kumar, Nepak Devadutta
  • Publication number: 20130331542
    Abstract: An efficient, eco-friendly, solvent-free process for preparing hyperbranched polyesters by reacting polyols with polycarboxylic acid in the presence of heterogeneous, reusable, acid, crystalline, micro-mesoporous double-metal cyanide catalyst at moderate temperatures and short period of reaction time.
    Type: Application
    Filed: February 23, 2012
    Publication date: December 12, 2013
    Applicant: COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH
    Inventors: Darbha Srinivas, Joby Sebastian
  • Patent number: 8124801
    Abstract: Processes for preparation of fatty acid alkyl esters are described herein. The processes include contacting fatty acid glycerides with alcohols in the presence of a catalyst separating the reaction products from the catalyst, and separating the fatty acid alkyl esters from the reaction products. The catalyst includes a metal from Group VIB of the Periodic Table and an element from Group VA of the Periodic Table.
    Type: Grant
    Filed: June 24, 2009
    Date of Patent: February 28, 2012
    Assignee: Benefuel Inc.
    Inventors: Darbha Srinivas, Paul Ratnassamy, Sanjeevani Amrit Pardhy, Thirumalaiswamy Raja, Shilpa Shirish Deshpande, Vijay Vasant Bokade, Kashinath Joti Wagmare, Arshia Altaf Lalljee, Surya Prakash Babu, Karukappadath Kunjimoideen Abdul Rashid, Khaliji Anas, Chennampilly Ummer Aniz
  • Publication number: 20110015447
    Abstract: The present invention provides a process for the preparation of biofuels or biofuel additives from glycerol. More particularly, it provides a process for the preparation of glycerol-ethers by etherification of glycerol with an alcohol in the presence of solid acid catalyst.
    Type: Application
    Filed: March 13, 2008
    Publication date: January 20, 2011
    Inventors: Darbha Srinivas, Paul Ratnasamy, Lakshi Saikia
  • Patent number: 7754643
    Abstract: The present invention provides a novel transesterification catalyst having the general formula: Zn3M2(CN)n(ROH).xZnCl2.yH2O wherein R is tertiary-butyl and M is a transition metal ion selected from Fe, Co and Cr, x varies from 0 to 0.5, y varies from 3-5 and n is 10 or 12. The above said catalyst is useful for an efficient transesterification of glycerides, fatty acid esters and cyclic carbonates on reactions with alcohols.
    Type: Grant
    Filed: March 30, 2006
    Date of Patent: July 13, 2010
    Assignee: Council of Scientific & Industrial Research
    Inventors: Darbha Srinivas, Rajendra Srivastava, Paul Ratnasamy
  • Publication number: 20090326252
    Abstract: Processes for preparation of fatty acid alkyl esters are described herein. The processes include contacting fatty acid glycerides with alcohols in the presence of a catalyst separating the reaction products from the catalyst, and separating the fatty acid alkyl esters from the reaction products. The catalyst includes a metal from Group VIB of the Periodic Table, a metal from Group IIIA of the Periodic Table, and an element from Group VA of the Periodic Table.
    Type: Application
    Filed: June 24, 2009
    Publication date: December 31, 2009
    Inventors: Darbha Srinivas, Paul Ratnasamy, Sanjeevani Amrit Pardhy, Thirumalaiswamy Raja, Shilpa Shirish Deshpande, Vijay Vasant Bokade, Kashinath Joti Wagmare, Arshia Altaf Lalljee, Surya Prakash Babu, Karukappadath Kunjimoideen Abdul Rashid, Khaliji Anas, Chennampilly Ummer Aniz
  • Patent number: 7518012
    Abstract: The present invention provides a process for the preparation of dialkyl carbonates of general formula (1) wherein R=alkyl (C1-C8) or C6H5CH2 the said process comprises a reaction in between cyclic carbonate and alcohol, in the presence of a solid, double metal cyanide complex catalyst, at a temperature in the range of 140-180° C., for a period of 4-10 hrs, followed by the separation of catalyst from the above said reaction mixture by known methods to obtain the desired product.
    Type: Grant
    Filed: March 30, 2006
    Date of Patent: April 14, 2009
    Assignee: Council of Scientific & Industrial Research
    Inventors: Darbha Srinivas, Rajendra Srivastava, Paul Ratnasamy
  • Patent number: 7482480
    Abstract: The present invention provides a process for the preparation of hydrocarbon fuels, which comprises contacting fatty acid glycerides with alcohols in the presence of a solid, double metal cyanide catalyst at a temperature in the range of 150° to 200° C. for a period of 2-6 hrs and separating the catalyst from the above said reaction mixture to obtain the desired hydrocarbon fuel.
    Type: Grant
    Filed: March 30, 2006
    Date of Patent: January 27, 2009
    Assignee: Council of Scientific & Industrial Research
    Inventors: Darbha Srinivas, Rajendra Srivastava, Paul Ratnasamy
  • Patent number: 7405319
    Abstract: The present invention provides an improved process for the preparation of carbamates with high selectivity of pharmaceutical interest by an eco-friendly, non-toxic, phosgene-/isocyanate-/CO-free clean route through a reaction of amine, organic halide compound and carbon dioxide in the presence of a solid, reusable catalyst at moderate conditions and does not require additional cocatalyst/promoter as well as solvent.
    Type: Grant
    Filed: May 22, 2006
    Date of Patent: July 29, 2008
    Assignee: Council of Scientific and Industrial Research
    Inventors: Darbha Srinivas, Rajendra Srivastava, Paul Ratnasamy
  • Patent number: 7375224
    Abstract: The present invention provides an adenine modified solid, ordered, mesoporous, bifunctional, organo-inorganic silica-based catalyst, its method of preparation and also a process for the production of cyclic carbonates of the formula hereinbelow wherein R?H, CH2Cl, CH3, C4H9, C6H11, C6H5.
    Type: Grant
    Filed: May 23, 2006
    Date of Patent: May 20, 2008
    Assignee: Council of Scientific and Industrial Research
    Inventors: Darbha Srinivas, Rajendra Srivastava, Paul Ratnasamy
  • Patent number: 7365214
    Abstract: The present invention provides an improved process for the preparation of cyclic carbonates which comprises reacting an olefins or its epoxide with carbon dioxide or a mixture of oxygen-containing compound and carbon dioxide, in the presence of zeolite-based catalyst and a Lewis base co-catalyst, at a minimum pressure of 30 psig and temperature between 40 to 120° C. for 0.5 to 4 hrs., separating the catalyst and recovering the corresponding cyclic carbonate formed by conventional methods.
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: April 29, 2008
    Assignee: Council of Scientific and Industrial Research
    Inventors: Darbha Srinivas, Rajendra Srivastava
  • Publication number: 20070276146
    Abstract: The present invention provides an adenine modified solid, ordered, mesoporous, bifunctional, organo-inorganic silica-based catalyst, its method of preparation and also a process for the production of cyclic carbonates of the formula hereinbelow wherein R?H, CH2Cl, CH3, C4H9, C6H11, C6H5
    Type: Application
    Filed: May 23, 2006
    Publication date: November 29, 2007
    Applicant: COUNCIL OF SCIENTIFIC AND INDUSTRIAL RESEARCH
    Inventors: Darbha Srinivas, Rajendra Srivastava, Paul Ratnasamy
  • Publication number: 20070270605
    Abstract: The present invention provides an improved process for the preparation of carbamates with high selectivity of pharmaceutical interest by an eco-friendly, non-toxic, phosgene-/isocyanate-/CO-free clean route through a reaction of amine, organic halide compound and carbon dioxide in the presence of a solid, reusable catalyst at moderate conditions and does not require additional cocatalyst/promoter as well as solvent
    Type: Application
    Filed: May 22, 2006
    Publication date: November 22, 2007
    Inventors: Darbha Srinivas, Rajendra Srivastava, Paul Ratnasamy