Patents by Inventor Rathna P. Davuluri
Rathna P. Davuluri 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).
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Patent number: 9267083Abstract: Processes are provided herein for producing naphtha boiling range products with a desired sulfur content by reducing the mercaptan content of the naphtha boiling range products after the products exit a hydroprocessing stage. Due to mercaptan reversion, naphtha boiling range products that contain even small amounts of olefins can have a higher than expected sulfur content after hydroprocessing. In order to reduce or mitigate the effects of mercaptan reversion, microchannel reactors (or microreactors) can be placed in a processing system downstream of a reactor that produces a low sulfur naphtha product. The microreactors can include a coating of metals that have activity for hydrodesulfurization. By passing at least a portion of the naphtha product through the downstream microreactors, the mercaptans formed by reversion reactions can be reduced or eliminated, resulting in a naphtha product with possessing a very low sulfur content.Type: GrantFiled: December 3, 2013Date of Patent: February 23, 2016Assignee: ExxonMobil Research and Engineering CompanyInventors: Benjamin S. Umansky, Charles R. Bolz, Anjaneya S. Kovvali, Carlos N. Lopez, Rathna P. Davuluri
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Patent number: 9095831Abstract: The invention relates to a process of alkylating aromatic hydrocarbons, and more particularly a process of making paraxylene by alkylation of benzene and/or toluene with methanol and/or dimethyl ether, and to an apparatus for carrying out said process, the improvement comprising staged injection of one of the reactants, with the stages separated by structured packing so as to minimize at least one of gas phase back-mixing, by-pass phenomena, and gas bubble size.Type: GrantFiled: July 25, 2012Date of Patent: August 4, 2015Assignee: ExxonMobil Chemical Patents Inc.Inventors: Lu Han, Rathna P. Davuluri, Christopher G. Smalley, Mark P. Hagemeister, Masaaki Sugita, Joseph S. Famolaro, Robert G. Tinger
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Publication number: 20150101406Abstract: In various aspects, methods and systems are provided for monitoring catalyst bed levels using multiple sensors that are temporarily installed in a reactor during catalyst loading. The multiple sensors are able to take distance measurements at substantially the same time and at predetermined time intervals so as to provide a catalyst time profile. The catalyst time profile allows an operator monitor catalyst levels during and after catalyst loading. Once catalyst loading is completed, the multiple sensors are removed from the reactor.Type: ApplicationFiled: September 15, 2014Publication date: April 16, 2015Applicant: ExxonMobil Research and Engineering CompanyInventors: YI EN HUANG, David C. Dankworth, Keith Wilson, Manuel S. Alvarez, Rathna P. Davuluri, Jeffrey W. Frederick, Bryan A. Patel
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Patent number: 8999246Abstract: The liquid feed nozzle assemblies for a circulating fluid bed reactor comprise (i) a throttle body premixer to combine liquid feed with atomization steam upstream of a nozzle body to form a liquid feed/steam mixture comprising liquid feed droplets; (ii) a conduit connected to the venturi premixer and to a discharge nozzle body to convey a flow of the liquid/steam mixture created by the premixer to the nozzle body; (iii) a discharge nozzle connected to the flow conduit to shear the liquid feed/steam mixture to create liquid feed droplets of reduced size and (iv) a disperser at the outlet of the discharge nozzle to provide a spray jet of liquid feed having an increased surface area relative to a cylindrical jet. The nozzle assembles are particularly useful in fluid coking units using heavy oil feeds such a tar sands bitumen.Type: GrantFiled: May 17, 2011Date of Patent: April 7, 2015Assignee: ExxonMobil Research and Engineering CompanyInventors: Edward Chan, Brian Knapper, Eberhard Mueller, Jennifer McMillan, Jonathan Tyler, Darwin Edward Kiel, Rathna P. Davuluri
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Patent number: 8950570Abstract: A solids supply system having a solids deaeration zone and a solids pump zone, and a method for supplying the solids e.g., pulverized dry coal, to an application, e.g., gasification process. The solids deaeration zone includes a container having a passageway defined by one or more sloped walls. The solids deaeration zone is operable to deaerate and convey the solids to the solids pump zone. In the solids deaeration zone, the solids become sufficiently compacted prior to and upon entry into the solids pump zone to be effectively conveyed through the solids pump zone.Type: GrantFiled: December 7, 2010Date of Patent: February 10, 2015Assignee: ExxonMobil Research and Engineering CompanyInventors: James R. Bielenberg, Michael Raterman, Rathna P. Davuluri, John W. Fulton, Steven W. Meier
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Publication number: 20140174982Abstract: Processes are provided herein for producing naphtha boiling range products with a desired sulfur content by reducing the mercaptan content of the naphtha boiling range products after the products exit a hydroprocessing stage. Due to mercaptan reversion, naphtha boiling range products that contain even small amounts of olefins can have a higher than expected sulfur content after hydroprocessing. In order to reduce or mitigate the effects of mercaptan reversion, microchannel reactors (or microreactors) can be placed in a processing system downstream of a reactor that produces a low sulfur naphtha product. The microreactors can include a coating of metals that have activity for hydrodesulfurization. By passing at least a portion of the naphtha product through the downstream microreactors, the mercaptans formed by reversion reactions can be reduced or eliminated, resulting in a naphtha product with possessing a very low sulfur content.Type: ApplicationFiled: December 3, 2013Publication date: June 26, 2014Applicant: EXXONMOBIL RESEARCH AND ENGINEERING COMPANYInventors: Benjamin S. Umansky, Charles R. Bolz, Anjaneya S. Kovvali, Carlos N. Lopez, Rathna P. Davuluri
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Patent number: 8739962Abstract: A solids supply systems having a solids deaeration zone and a solids pump zone, and to methods for supplying the solids e.g., pulverized dry coal, to an application, e.g., gasification process. The solids deaeration zone includes a roller system containing a plurality of porous roller assemblies, or a belt system containing a plurality of porous belt assemblies. The solids deaeration zone is operable to deaerate and convey the solids to the solids pump zone. In the solids deaeration zone, the solids become sufficiently compacted prior to and upon entry into the solids pump zone to be effectively conveyed through the solids pump zone.Type: GrantFiled: December 7, 2010Date of Patent: June 3, 2014Assignee: ExxonMobil Research and Engineering CompanyInventors: James R. Bielenberg, Michael Raterman, Rathna P. Davuluri, John W. Fulton, Steven W. Meier
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Publication number: 20130165724Abstract: The invention relates to a process of alkylating aromatic hydrocarbons, and more particularly a process of making paraxylene by alkylation of benzene and/or toluene with methanol and/or dimethyl ether, and to an apparatus for carrying out said process, the improvement comprising staged injection of one of the reactants, with the stages separated by structured packing so as to minimize at least one of gas phase back-mixing, by-pass phenomena, and gas bubble size.Type: ApplicationFiled: July 25, 2012Publication date: June 27, 2013Inventors: Lu Han, Rathna P. Davuluri, Christopher G. Smalley, Mark Hagemeister, Masaaki Sugita, Joseph S. Famolaro, Robert G. Tinger
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Patent number: 8399727Abstract: In a process for the production of para-xylene, an aromatic feedstock comprising toluene and/or benzene is reacted with methanol under alkylation conditions in a reactor in the presence of a fluidized bed of solid catalyst particles to produce a vapor phase effluent comprising para-xylene, water, unreacted toluene and/or benzene and solid catalyst fines. The vapor phase effluent is contacted with a liquid hydrocarbon quench stream under conditions to condense a minor portion of the vapor phase effluent and produce a condensate which contains at least some of the catalyst fines and which is substantially free of an aqueous phase. The condensate containing said catalyst fines is then separated from the remainder of the vapor phase effluent.Type: GrantFiled: October 6, 2010Date of Patent: March 19, 2013Assignee: ExxonMobil Chemical Patents Inc.Inventors: James R. Lattner, Mark P. Hagemeister, Christopher Gordon Smalley, Jon Edmond Randolph Stanat, Timothy Paul Bender, Masaaki Sugita, Rathna P. Davuluri, Lu Han
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Patent number: 8202412Abstract: The present invention is an improved regenerated catalyst bend assembly for a fluid catalytic cracking unit. In a preferred embodiment, the reduced elevation (“RE-bend” or “REL-bend”) regenerated catalyst return line assembly of the present invention has an outlet elevation that is lower than the inlet elevation of the RE-bend or REL-bend regenerated catalyst return line assembly, and a process for utilizing the assembly in a fluid catalytic cracking unit. The present invention is especially useful in the modification of existing fluid catalytic cracking units to lower the elevation of the outlet of the regenerated catalyst return line assembly, thereby providing needed space to increase the fluid catalytic cracking reactor riser length.Type: GrantFiled: July 17, 2007Date of Patent: June 19, 2012Assignee: ExxonMobil Research and Engineering CompanyInventors: Brian A. Cunningham, Christopher G. Smalley, Rathna P. Davuluri, Dana W. Nouri
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Publication number: 20120063961Abstract: The liquid feed nozzle assemblies for a circulating fluid bed reactor comprise (i) a throttle body premixer to combine liquid feed with atomization steam upstream of a nozzle body to form a liquid feed/steam mixture comprising liquid feed droplets; (ii) a conduit connected to the venturi premixer and to a discharge nozzle body to convey a flow of the liquid/steam mixture created by the premixer to the nozzle body; (iii) a discharge nozzle connected to the flow conduit to shear the liquid feed/steam mixture to create liquid feed droplets of reduced size and (iv) a disperser at the outlet of the discharge nozzle to provide a spray jet of liquid feed having an increased surface area relative to a cylindrical jet. The nozzle assembles are particularly useful in fluid coking units using heavy oil feeds such a tar sands bitumen.Type: ApplicationFiled: May 17, 2011Publication date: March 15, 2012Applicant: EXXONMOBIL RESEARCH AND ENGINEERING COMPANYInventors: Edward CHAN, Brian KNAPPER, Eberhard MUELLER, Jennifer MCMILLAN, Jonathan TYLER, Darwin KIEL, Rathna P. DAVULURI
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Publication number: 20110139583Abstract: A solids supply systems having a solids deaeration zone and a solids pump zone, and to methods for supplying the solids e.g., pulverized dry coal, to an application, e.g., gasification process. The solids deaeration zone includes a roller system containing a plurality of porous roller assemblies, or a belt system containing a plurality of porous belt assemblies. The solids deaeration zone is operable to deaerate and convey the solids to the solids pump zone. In the solids deaeration zone, the solids become sufficiently compacted prior to and upon entry into the solids pump zone to be effectively conveyed through the solids pump zone.Type: ApplicationFiled: December 7, 2010Publication date: June 16, 2011Applicant: EXXONMOBIL RESEARCH AND ENGINEERING COMPANYInventors: James R. Bielenberg, Michael Raterman, Rathna P. Davuluri, John W. Fulton, Steven W. Meier
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Publication number: 20110139257Abstract: A solids supply system having a solids deaeration zone and a solids pump zone, and a method for supplying the solids e.g., pulverized dry coal, to an application, e.g., gasification process. The solids deaeration zone includes a container having a passageway defined by one or more sloped walls. The solids deaeration zone is operable to deaerate and convey the solids to the solids pump zone. In the solids deaeration zone, the solids become sufficiently compacted prior to and upon entry into the solids pump zone to be effectively conveyed through the solids pump zone.Type: ApplicationFiled: December 7, 2010Publication date: June 16, 2011Applicant: EXXONMOBIL RESEARCH AND ENGINEERING COMPANYInventors: James R. Bielenberg, Michael Raterman, Rathna P. Davuluri, John W. Fulton, Steven W. Meier
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Publication number: 20110114468Abstract: An improved, fouling-resistant configuration for the stripper sheds of fluid coking units comprises an inverted, open-bottomed channel with apertures spaced along the length of the channel and spaced from the apex of the channel. Preferably, the channels are of an inverted-V configuration with a downwardly extending lip provided on each side of the channel, extending from the bottom edge of each side of the channel. The stripper sheds may be positioned parallel to one another in the stripper section of the reactor vessel or, alternatively, the sheds in different tiers in the stripper section may be disposed so that the longitudinal axes of the sheds are rotated angularly relative to the sheds in other rows.Type: ApplicationFiled: October 21, 2010Publication date: May 19, 2011Applicant: EXXONMOBIL RESEARCH AND ENGINEERING COMPANYInventors: Rathna P. DAVULURI, James R. BIELENBERG, Clay R. SUTTON, Brenda A. RAICH
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Publication number: 20110092756Abstract: In a process for the production of para-xylene, an aromatic feedstock comprising toluene and/or benzene is reacted with methanol under alkylation conditions in a reactor in the presence of a fluidized bed of solid catalyst particles to produce a vapor phase effluent comprising para-xylene, water, unreacted toluene and/or benzene and solid catalyst fines. The vapor phase effluent is contacted with a liquid hydrocarbon quench stream under conditions to condense a minor portion of the vapor phase effluent and produce a condensate which contains at least some of the catalyst fines and which is substantially free of an aqueous phase. The condensate containing said catalyst fines is then separated from the remainder of the vapor phase effluent.Type: ApplicationFiled: October 6, 2010Publication date: April 21, 2011Inventors: James R. Lattner, Mark P. Hagemeister, Christopher Gordon Smalley, Jon Edmond Randolph Stanat, Timothy Paul Bender, Masaaki Sugita, Rathna P. Davuluri, Lu Han
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Patent number: 7744746Abstract: This invention relates to the catalytic cracking of a hydrocarbon feed. In particular, this invention relates to an apparatus and process utilizing a catalyst stripper section of a fluid catalytic cracking (FCC) reactor with chordal trays designed to provide improved stripping of hydrocarbons from spent FCC catalyst in an FCC reactor stripping zone.Type: GrantFiled: March 28, 2007Date of Patent: June 29, 2010Assignee: ExxonMobil Research and Engineering CompanyInventors: Brian A. Cunningham, Christopher G. Smalley, Richard C. Senior, Joseph S. Famolaro, Rathna P. Davuluri, David L. Johnson, James H. Beech, Jeffrey S. Smith
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Patent number: 7670478Abstract: This invention relates to an apparatus and process for injecting a petroleum feed. More particularly, a liquid petroleum feed is atomized with a nozzle assembly apparatus in which the apparatus has injection nozzles that produce a generally flat spray pattern of finely dispersed feed. The injection nozzles are each designed such that the overall effect of the different spray patterns from the individual nozzles provides a more uniform feed coverage across the catalyst stream.Type: GrantFiled: November 3, 2005Date of Patent: March 2, 2010Assignee: ExxonMobil Research and Engineering CompanyInventors: George A. Swan, III, Rustom M. Billimoria, Rathna P. Davuluri, Steven S. Lowenthal, Todd R. Steffens, Christopher G. Smalley
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Publication number: 20090020454Abstract: The present invention is an improved regenerated catalyst bend assembly for a fluid catalytic cracking unit. In a preferred embodiment, the reduced elevation (“RE-bend” or “REL-bend”) regenerated catalyst return line assembly of the present invention has an outlet elevation that is lower than the inlet elevation of the RE-bend or REL-bend regenerated catalyst return line assembly, and a process for utilizing the assembly in a fluid catalytic cracking unit. The present invention is especially useful in the modification of existing fluid catalytic cracking units to lower the elevation of the outlet of the regenerated catalyst return line assembly, thereby providing needed space to increase the fluid catalytic cracking reactor riser length.Type: ApplicationFiled: July 17, 2007Publication date: January 22, 2009Inventors: Brian A. Cunningham, Christopher G. Smalley, Rathna P. Davuluri, Dana W. Nouri
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Patent number: 7414166Abstract: This invention provides feed introduction devices, and processes for using same, which minimize catalyst clogging. In particular, the invention is to a feed introduction device having a first end in fluid communication with a feed source, a second end in fluid communication with a reactor and a deviation zone between the first end and the second end to deviate the flow of feed about a deviation angle from the first end toward the second end. According to the invention, the deviation angle is greater than 90 degrees.Type: GrantFiled: October 5, 2004Date of Patent: August 19, 2008Assignee: ExxonMobil Chemical Patents Inc.Inventors: James H. Beech, Jr., Brian A. Cunningham, Christopher G. Smalley, Rathna P. Davuluri
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Patent number: 7407572Abstract: This invention relates to an apparatus and process for atomizing a petroleum feed. More particularly, a liquid petroleum feed is atomized with an atomization apparatus in which the apparatus has an orifice that produces a generally flat spray pattern of finely dispersed feed prior to contacting catalyst in a fluid catalytic cracking zone. The orifice has a general aspect ratio greater than 1.0 and a ratio of perimeter length-to-cross-sectional area greater than 1.5 relative to a perimeter-to-cross-sectional area ratio of a circular orifice of equivalent area. The apparatus can be used to atomize feed injected into the cracking zone of a fluid catalytic cracker.Type: GrantFiled: June 3, 2005Date of Patent: August 5, 2008Assignee: ExxonMobil Research and Engineering CompanyInventors: Todd R. Steffens, Thomas E. Hewitt, Rathna P. Davuluri, Enrique Feliz