Patents by Inventor Ramesh R. Hemrajani

Ramesh R. Hemrajani 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: 8658028
    Abstract: A process for removing elemental sulfur from liquid hydrocarbon steams such as transportation fuel streams, e.g. gasoline, diesel, kerosene, and jet, by contacting such streams with an immiscible aqueous solution under static mixing conditions. The aqueous solution contains a caustic and an effective amount of a Group I or Group II metal sulfide or polysulfide. The elemental sulfur in the stream is converted to a polysulfide that is not soluble in the hydrocarbon stream but is soluble in the aqueous solution, thus resulting in a hydrocarbon product stream having a substantially lower level of elemental sulfur.
    Type: Grant
    Filed: January 17, 2008
    Date of Patent: February 25, 2014
    Assignee: ExxonMobil Research and Engineering Company
    Inventors: Ashok Uppal, Ramesh R. Hemrajani, Robert J. Falkiner, Lawrence J. Lawlor, Joseph L. Feimer
  • Patent number: 8383874
    Abstract: A reactor for the autorefrigerant alkylation process has a reactor vessel with a lower end inlet for the refrigerant reactant and the sulfuric acid and a series of inlets for the olefin reactant at vertically spaced intervals. A flow path for the reactants is provided by co-acting baffles which define sequential reaction zones. The baffles interact with a rotary mixer with multiple impellers to provide agitation. Outlets for the vaporized refrigerant and the reaction effluent are provided at the upper end of the vessel. In the alkylation process, the liquid isoparaffin hydrocarbon reactant/refrigerant with a sulfuric acid alkylation catalyst is introduced into the lower end and passed along the extended reactant flow path with the olefin reactant introduced at intervals along the path. The reaction mixture flows in the sequence of serial reaction zones within the reactor to promote mixing of the isoparaffin reactant with the acid catalyst.
    Type: Grant
    Filed: December 22, 2011
    Date of Patent: February 26, 2013
    Assignee: ExxonMobil Research and Engineering Company
    Inventors: Ramon A. Strauss, Ramesh R. Hemrajani, Guido L. Spinelli
  • Publication number: 20120130140
    Abstract: A reactor for the autorefrigerant alkylation process has a reactor vessel with a lower end inlet for the refrigerant reactant and the sulfuric acid and a series of inlets for the olefin reactant at vertically spaced intervals. A flow path for the reactants is provided by co-acting baffles which define sequential reaction zones. The baffles interact with a rotary mixer with multiple impellers to provide agitation. Outlets for the vaporized refrigerant and the reaction effluent are provided at the upper end of the vessel. In the alkylation process, the liquid isoparaffin hydrocarbon reactant/refrigerant with a sulfuric acid alkylation catalyst is introduced into the lower end and passed along the extended reactant flow path with the olefin reactant introduced at intervals along the path. The reaction mixture flows in the sequence of serial reaction zones within the reactor to promote mixing of the isoparaffin reactant with the acid catalyst.
    Type: Application
    Filed: December 22, 2011
    Publication date: May 24, 2012
    Applicant: EXXONMOBIL RESEARCH AND ENGINEERING COMPANY
    Inventors: Ramon A. STRAUSS, Ramesh R. HEMRAJANI, Guido L. SPINELLI
  • Patent number: 8119084
    Abstract: A reactor for the autorefrigerant alkylation process has a cylindrical upright reactor vessel with the inlet for the refrigerant reactant and the sulfuric acid at its lower end and a series of inlets for the olefin reactant at vertically spaced intervals up the length of the reactor. An extended, sinuous flow path for the reactants is provided by means co-acting baffles co-acting baffles having, alternately along the length of the reactor, central flow passages and peripheral flow passages for the reaction mixture to define sequential reaction zones in which alkylation takes place. The baffles interact with a rotary mixer with multiple impellers located on the reactor axis. The reaction mixture flows alternately towards and away from the reactor walls in the sequence of serial reaction zones within the reactor to promote mixing of the isoparaffin reactant with the acid catalyst.
    Type: Grant
    Filed: February 24, 2009
    Date of Patent: February 21, 2012
    Assignee: ExxonMobil Research & Engineering Company
    Inventors: Ramon A. Strauss, Ramesh R. Hemrajani, Guido L. Spinelli
  • Patent number: 7947232
    Abstract: An improved reactor for an HF alkylation unit of the shell-and-tube heat exchanger type has an axial tube bundle to provide cooling for the reactor and a centrally-located axial sparger system for injecting and dispersing the hydrocarbon reactants into the flow path in the reactor. The sparger comprises an axially-extensive tube with outlet nozzles for the hydrocarbon reactants arranged around the tube, preferably with differing radial angles, at different locations along the length of the sparger.
    Type: Grant
    Filed: November 30, 2007
    Date of Patent: May 24, 2011
    Assignee: ExxonMobil Research & Engineering Company
    Inventors: Ramon A. Strauss, Ramesh R. Hemrajani
  • Publication number: 20100072109
    Abstract: A process for removing elemental sulfur from liquid hydrocarbon steams such as transportation fuel streams, e.g. gasoline, diesel, kerosene, and jet, by contacting such streams with an immiscible aqueous solution under static mixing conditions. The aqueous solution contains a caustic and an effective amount of a Group I or Group II metal sulfide or polysulfide. The elemental sulfur in the stream is converted to a polysulfide that is not soluble in the hydrocarbon stream but is soluble in the aqueous solution, thus resulting in a hydrocarbon product stream having a substantially lower level of elemental sulfur.
    Type: Application
    Filed: January 17, 2008
    Publication date: March 25, 2010
    Inventors: Ashok Uppal, Ramesh R. Hemrajani, Robert J. Falkiner, Lawrence J. Lawlor, Joseph L. Feimer
  • Publication number: 20090287033
    Abstract: An improved reactor for the autorefrigerant alkylation process has a generally cylindrical upright reactor vessel with the inlet for the refrigerant reactant and the sulfuric acid at its lower end and a series of inlets for the olefin reactant at vertically spaced intervals up the length of the reactor. An extended, sinuous flow path for the reactants is provided by means co-acting baffles which define sequential reaction zones in which alkylation takes place. The baffles interact with a rotary mixer with multiple impellers located on the reactor axis which provides agitation to the mixture ascending the reactor additional to that created by the ebullition of the refrigerant. Outlets for the vaporized refrigerant and the reaction effluent are provided at the upper end of the vessel.
    Type: Application
    Filed: February 24, 2009
    Publication date: November 19, 2009
    Applicant: ExxonMobil Research and Engineering Company
    Inventors: Ramon A. Strauss, Ramesh R. Hemrajani, Guido L. Spinelli
  • Publication number: 20090221863
    Abstract: An HF alkylation process for producing gasoline boiling range alkylate product by the alkylation of a light olefin with an isoparaffin in the presence of hydrogen fluoride as an alkylation catalyst, in which the content of organic fluorides in the alkylation product stream is reduced by recontact with additional HF alkylation acid after which the hydrocarbon phase and the denser acid-containing phase are separated in a hydrocyclone. The use of the hydrocyclone enables the acid inventory of the unit to be significantly reduced which still achieving satisfactory removal of the unwanted fluoride by-products.
    Type: Application
    Filed: January 26, 2009
    Publication date: September 3, 2009
    Applicant: ExxonMobil Research and Engineering Comapny
    Inventors: Ramon A. Strauss, Brian A. Cunningham, Jeffrey M. Fitt, Ramesh R. Hemrajani
  • Publication number: 20080138259
    Abstract: An improved reactor for an HF alkylation unit of the shell-and-tube heat exchanger type has an axial tube bundle to provide cooling for the reactor and a centrally-located axial sparger system for injecting and dispersing the hydrocarbon reactants into the flow path in the reactor. The sparger comprises an axially-extensive tube with outlet nozzles for the hydrocarbon reactants arranged around the tube, preferably with differing radial angles, at different locations along the length of the sparger.
    Type: Application
    Filed: November 30, 2007
    Publication date: June 12, 2008
    Applicant: ExxonMobil Research and Engineering Company
    Inventors: Ramon A. Strauss, Ramesh R. Hemrajani
  • Patent number: 7332138
    Abstract: A fixed bed catalytic reactor for converting process fluids having an upper catalyst bed and a lower catalyst bed below the upper catalyst bed for converting process fluids flowing through the upper and lower beds. A mixing zone is located between the upper bed and lower beds, and at least one jet is provided for injecting an inclined fluid jet into the mixing zone against the flow of the process fluids to entrain process fluids within the jet and to radially mix the process fluids across the mixing zone.
    Type: Grant
    Filed: July 26, 2002
    Date of Patent: February 19, 2008
    Assignee: ExxonMobil Research and Engineering Company
    Inventors: Ramesh Gupta, Robert Koros, Ramesh R. Hemrajani
  • Patent number: 7008536
    Abstract: The invention includes a method for dewatering and/or desalting a water-in-oil emulsion comprising introducing a plurality of streams of the emulsion into the electrostatic field under opposed flow whereby the water coalescence is enhanced. The invention also includes an improved electrostatic apparatus for dewatering and/or desalting a water-in-oil emulsion comprising a plurality of horizontally directed nozzles positioned to introduce a plurality of streams of the emulsion into the electrostatic field under opposed flow conditions.
    Type: Grant
    Filed: April 25, 2003
    Date of Patent: March 7, 2006
    Assignee: ExxonMobil Research and Engineering Co.
    Inventors: Ramesh Varadaraj, Rutton D. Patel, Ramesh R. Hemrajani, Salvatore J. Rossetti, David W. Savage
  • Patent number: 6860985
    Abstract: The invention relates to a method for improving yield in petroleum streams derived from coking processes. In a preferred embodiment, the invention relates to a method for regenerating filters employed to remove particulate matter from coker gas oil to improve coker gas oil yield and yield of upgraded coker gas oil products.
    Type: Grant
    Filed: November 12, 2002
    Date of Patent: March 1, 2005
    Assignee: ExxonMobil Research and Engineering Company
    Inventors: Michael Siskin, Ramesh R. Hemrajani, Glen E. Phillips, Simon R. Kelemen, Kuangnan Qian
  • Publication number: 20030217971
    Abstract: The invention includes a method for dewatering and/or desalting a water-in-oil emulsion comprising introducing a plurality of streams of the emulsion into the electrostatic field under opposed flow whereby the water coalescence is enhanced. The invention also includes an improved electrostatic apparatus for dewatering and/or desalting a water-in-oil emulsion comprising a plurality of horizontally directed nozzles positioned to introduce a plurality of streams of the emulsion into the electrostatic field under opposed flow conditions.
    Type: Application
    Filed: April 25, 2003
    Publication date: November 27, 2003
    Inventors: Ramesh Varadaraj, Rutton D. Patel, Ramesh R. Hemrajani, Salvatore J. Rossetti, David W. Savage
  • Publication number: 20030106838
    Abstract: The invention relates to a method for improving yield in petroleum streams derived from coking processes. In a preferred embodiment, the invention relates to a method for regenerating filters employed to remove particulate matter from coker gas oil to improve coker gas oil yield and yield of upgraded coker gas oil products.
    Type: Application
    Filed: November 12, 2002
    Publication date: June 12, 2003
    Inventors: Michael Siskin, Ramesh R. Hemrajani, Glen E. Phillips, Simon R. Kelemen, Kuangnan Qian
  • Patent number: 6228239
    Abstract: In one embodiment, the invention is related to a process for desalting crude oil that requires less wash water than conventional desalting methods. In the preferred embodiment of the invention, a chemical demulsifier formulation comprising an emulsion-breaking chemical and a solvent carrier is added to the crude oil. Wash water is then added to the crude oil until the volume of water in the oil ranges from about 0.1 to about 3 vol. %. Subsequently, the mixture of crude oil, wash water, and chemical demulsifier formulation is subjected to opposed-flow mixing. Chemical emulsion-breakers useful in the invention have a hydrophobic tail group and a hydrophilic head group. Preferably, the emulsion breaker has the formula: x ranges from 1 to 5, y ranges from 0 to 2, and R is an alkyl group having 4-9 carbon atoms, and n ranges from 3 to 9.
    Type: Grant
    Filed: February 26, 1999
    Date of Patent: May 8, 2001
    Assignee: Exxon Research and Engineering Company
    Inventors: Pacifico V. Manalastas, Ramesh Varadaraj, David W. Savage, Guido Sartori, Ramesh R. Hemrajani, Cornelius Hendrick Brons
  • Patent number: 6037445
    Abstract: A continuous process for functionalizing polymers is disclosed, wherein (A) a liquid comprising the polymer and a gas comprising a functionalizing agent are continuously introduced into a dispersing zone operated in laminar flow with high intensity mixing of the liquid and the gas under functionalization conditions, wherein the mixing is conducted for a period of the dispersing zone residence time at a shear rate effective to form a stable gas-liquid dispersion in which the gas is substantially dissolved or dispersed in the liquid for functionalization, and wherein the shear rate is less than about 5 s.sup.-1 for no more than about 30% of the residence time; (B) the gas-liquid dispersion is continuously passed to a blending zone operated in laminar flow with low intensity mixing under functionalization conditions, wherein the mixing is conducted at a shear rate effective to further dissolve the gas into the liquid for further functionalization; and (C) continuously recovering functionalized polymer.
    Type: Grant
    Filed: December 30, 1997
    Date of Patent: March 14, 2000
    Assignees: Exxon Chemical Patents, Inc., Koch-Glitsch, Inc.
    Inventors: David C. Dankworth, Chris F. Meyer, William B. Eckstrom, Ramesh R. Hemrajani, Salvatore Rea, Jon E. Stanat
  • Patent number: 5324853
    Abstract: A process for the catalytic or non-catalytic esterification of acids or anhydrides with a mono-alcohol or a polyhydroxy compound which comprises the steps of adding the reagents to a reaction vessel to form a reaction mixture, and heating the reaction mixture and maintaining a pressure sufficient to obtain boiling of the reaction mixture thereby causing esterification and removing water as vapor while continuously mixing the reaction mixture in the reactor vessel such that at least about 2.5 to about 20 volumes of reaction mixture are internally recirculated per minute, whereby the rate of conversion is enhanced.
    Type: Grant
    Filed: January 19, 1993
    Date of Patent: June 28, 1994
    Assignee: Exxon Chemical Patents Inc.
    Inventors: Larry O. Jones, Glen W. Davis, John Lyford, IV, Sun-tsun Fong, Ramesh R. Hemrajani
  • Patent number: 5156458
    Abstract: The present invention is directed toward the dampening of concentration variations in fluid streams, especially concentration variations that are substantially sinusoidal, by subjecting such streams to a plurality of backmixing steps whereby such concentration variations are reduced.In one embodiment of the present invention, there is provided a surge drum that is divided into a predetermined number of mixing stages, each of which is provided with means to create a fluid jet stream at substantially the inlet of the mixing stage and baffle means positioned with respect to the inlet jet for reversing the flow of the jet.
    Type: Grant
    Filed: March 13, 1989
    Date of Patent: October 20, 1992
    Assignee: Exxon Research and Engineering Company
    Inventors: Ramesh R. Hemrajani, Peter R. Ponzi