Patents by Inventor Ajit Ramchandra Pradhan

Ajit Ramchandra Pradhan 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: 9851315
    Abstract: A method for determining the concentration of asphaltenes in a solution is described. A model is first established for estimating the concentration of asphaltenes in a solution based on multiple samples of solutions of asphaltenes in the solvent in which the concentrations are known. The multiple samples have varying concentrations of asphaltenes. The diffusivity and relaxation time are measured for each sample using two-dimensional NMR. The ratio of diffusivity to relaxation time for each sample is then calculated. A linear equation is determined to fit the relationship between the ratio of diffusivity to relaxation time and the asphaltene concentration by weight for the multiple samples, thus creating the model. For a given solution sample for which the concentration of asphaltenes is desired to be determined, diffusivity and relaxation time are determined using two-dimensional NMR, and the ratio of diffusivity to relaxation time is calculated.
    Type: Grant
    Filed: December 11, 2014
    Date of Patent: December 26, 2017
    Assignee: Chevron U.S.A. Inc.
    Inventors: Zheng Yang, Boqin Sun, Ajit Ramchandra Pradhan, Hussein Alboudwarej, Dengen Zhou
  • Publication number: 20160169820
    Abstract: A method for determining the concentration of asphaltenes in a solution is described. A model is first established for estimating the concentration of asphaltenes in a solution based on multiple samples of solutions of asphaltenes in the solvent in which the concentrations are known. The multiple samples have varying concentrations of asphaltenes. The diffusivity and relaxation time are measured for each sample using two-dimensional NMR. The ratio of diffusivity to relaxation time for each sample is then calculated. A linear equation is determined to fit the relationship between the ratio of diffusivity to relaxation time and the asphaltene concentration by weight for the multiple samples, thus creating the model. For a given solution sample for which the concentration of asphaltenes is desired to be determined, diffusivity and relaxation time are determined using two-dimensional NMR, and the ratio of diffusivity to relaxation time is calculated.
    Type: Application
    Filed: December 11, 2014
    Publication date: June 16, 2016
    Applicant: Chevron U.S.A. Inc.
    Inventors: Zheng Yang, Boqin Sun, Ajit Ramchandra Pradhan, Hussein Alboudwarej, Dengen Zhou
  • Patent number: 8293962
    Abstract: A process for producing a gasoline blending component and a middle distillate, comprising adjusting a level of a halide containing additive provided to an ionic liquid alkylation reactor to shift selectivity towards heavier products, and recovering a low volatility gasoline blending component and the middle distillate.
    Type: Grant
    Filed: April 10, 2012
    Date of Patent: October 23, 2012
    Assignee: Chevron U.S.A. Inc.
    Inventors: Sven Ivar Hommeltoft, Stephen Joseph Miller, Ajit Ramchandra Pradhan
  • Publication number: 20120226086
    Abstract: A process for producing a gasoline blending component and a middle distillate, comprising adjusting a level of a halide containing additive provided to an ionic liquid alkylation reactor to shift selectivity towards heavier products, and recovering a low volatility gasoline blending component and the middle distillate.
    Type: Application
    Filed: April 10, 2012
    Publication date: September 6, 2012
    Applicant: Chevron U.S.A. Inc.
    Inventors: Sven Ivar Hommeltoft, Stephen Joseph Miller, Ajit Ramchandra Pradhan
  • Patent number: 8252968
    Abstract: A process for producing a low volatility gasoline blending component and a middle distillate, comprising alkylating a hydrocarbon stream comprising at least one olefin having from 2 to 4 carbon atoms and at least one paraffin having from 4 to 6 carbon atoms with an ionic liquid catalyst and an unsupported halide containing additive, and separating the alkylate into at least the low volatility gasoline blending component and the middle distillate, wherein the middle distillate is a fuel suitable for use as a jet fuel or jet fuel blending component. Also, a process for producing a gasoline blending component and a middle distillate, comprising adjusting a level of a halide containing additive provided to an ionic liquid alkylation reactor to shift selectivity towards heavier products, and recovering a low volatility gasoline blending component and the middle distillate. Also, processes comprising alkylating isobutane with butene over specific chloroaluminate ionic liquids.
    Type: Grant
    Filed: February 25, 2011
    Date of Patent: August 28, 2012
    Assignee: Chevron U.S.A. Inc.
    Inventors: Sven Ivar Hommeltoft, Stephen J. Miller, Ajit Ramchandra Pradhan
  • Patent number: 8051020
    Abstract: A method for predicting properties of lubricant base oil blends, comprising the steps of generating an NMR spectrum, HPLC-UV spectrum, and FIMS spectrum of a sample of a blend of at least two lubricant base oils and determining at least one composite structural molecular parameter of the sample from said spectrums. SIMDIST and HPO analyses of the sample are then generated in order to determine a composite boiling point distribution and molecular weight of the sample from such analysis. A composite structural molecular parameter is applied, and the composite boiling point distribution and the composite molecular weight to a trained neural network is trained to correlate with the composite structural molecular parameter composite boiling point distribution and the composite molecular weight so as to predict composite properties of the sample. The properties comprise Kinematic Viscosity at 40 C, Kinematic Viscosity at 100 C, Viscosity Index, Cloud Point, and Oxidation Performance.
    Type: Grant
    Filed: December 17, 2008
    Date of Patent: November 1, 2011
    Assignee: Chevron U.S.A. Inc.
    Inventors: Ajit Ramchandra Pradhan, John M. Rosenbaum, Nancy J. Bertrand, David C. Kramer, Allan G. Hee, Max I. Chang
  • Publication number: 20110147269
    Abstract: A process for producing a low volatility gasoline blending component and a middle distillate, comprising alkylating a hydrocarbon stream comprising at least one olefin having from 2 to 4 carbon atoms and at least one paraffin having from 4 to 6 carbon atoms with an ionic liquid catalyst and an unsupported halide containing additive, and separating the alkylate into at least the low volatility gasoline blending component and the middle distillate, wherein the middle distillate is a fuel suitable for use as a jet fuel or jet fuel blending component. Also, a process for producing a gasoline blending component and a middle distillate, comprising adjusting a level of a halide containing additive provided to an ionic liquid alkylation reactor to shift selectivity towards heavier products, and recovering a low volatility gasoline blending component and the middle distillate. Also, processes comprising alkylating isobutane with butene over specific chloroaluminate ionic liquids.
    Type: Application
    Filed: February 25, 2011
    Publication date: June 23, 2011
    Inventors: Sven Ivar Hommeltoft, Stephen J. Miller, Ajit Ramchandra Pradhan
  • Publication number: 20100049681
    Abstract: A method for predicting properties of lubricant base oil blends, comprising the steps of generating an NMR spectrum, HPLC-UV spectrum, and FIMS spectrum of a sample of a blend of at least two lubricant base oils and determining at least one composite structural molecular parameter of the sample from said spectrums. SIMDIST and HPO analyses of the sample are then generated in order to determine a composite boiling point distribution and molecular weight of the sample from such analysis. A composite structural molecular parameter is applied, and the composite boiling point distribution and the composite molecular weight to a trained neural network is trained to correlate with the composite structural molecular parameter composite boiling point distribution and the composite molecular weight so as to predict composite properties of the sample. The properties comprise Kinematic Viscosity at 40 C, Kinematic Viscosity at 100 C, Viscosity Index, Cloud Point, and Oxidation Performance.
    Type: Application
    Filed: December 17, 2008
    Publication date: February 25, 2010
    Inventors: Ajit Ramchandra Pradhan, John M. Rosenbaum, Nancy J. Bertrand, David C. Kramer, Allan G. Hee, Max I. Chang
  • Patent number: 7425524
    Abstract: A multigrade automotive gear lubricant comprising a base oil having a traction coefficient less than 0.021. A method for saving energy using a gear lubricant, comprising blending a multigrade gear lubricant by adding a base oil having a traction coefficient less than 0.021, and using the gear lubricant in an axle or differential. A process for making an energy saving automotive gear lubricant having a kinematic viscosity at 100° C. greater than 10 cSt. A gear lubricant comprising a FT derived base oil having a VI greater than 150 and a traction coefficient less than 0.015. A finished lubricant, comprising a FT derived base oil having a traction coefficient less than 0.015. A base oil having a traction coefficient less than 0.011 and a 50 wt % boiling point greater than 582° C.
    Type: Grant
    Filed: April 7, 2006
    Date of Patent: September 16, 2008
    Assignee: Chevron U.S.A. Inc.
    Inventors: Michael J. Haire, John A. Zakarian, John M. Rosenbaum, Nancy J. Bertrand, Stephen J. Miller, Trevor Miller, Vivek Palekar, Ajit Ramchandra Pradhan
  • Patent number: 6177374
    Abstract: This invention relates to a novel porous crystalline synthetic catalyst having the general formula expressed in the form of oxides: M 2/n o. x Al2O3 Y SiO2, Z ZnO wherein, M represents a proton and/or a metallic cation, n is the valence of the said cation, Y/x is a number ranging from 5 to 1000 (SiO2/Al2OS molar ratio), and a process for preparing such catalyst by (a) forming a reaction medium comprising water, a silicon source, an aluminium source, a zinc source and a source of structure directing agent capable of providing organic cations, (b) heating the said reaction mixture to a temperature ranging from 80° C. to 230° C. at autogeneous phase, and (c) heating the solid content obtained at the end of step (b) to a temperature greater than 400° C., so as to eliminate the organic species present due to the use of the structuring agent.
    Type: Grant
    Filed: January 17, 1997
    Date of Patent: January 23, 2001
    Assignee: Council of Scientific & Industrial Research
    Inventors: Ajit Ramchandra Pradhan, Nagabhatla Viswanadham, Surendranath Suresh, Nirmalya Ray, Uma Shanker, Turaga Sundara Rama Prasada Rao