Patents by Inventor Ajit B. Dandekar
Ajit B. Dandekar 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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Publication number: 20140044633Abstract: Methods and systems are provided for selective catalytic reduction of NOx with a low molecular low molecular weight hydrocarbon, e.g., propylene, as a reductant using a catalyst system including two catalysts. An exhaust stream containing an amount of NOx from a combustion operation is provided. A portion of the exhaust stream and a reductant stream including a low molecular weight hydrocarbon is introduced to a first catalytic reactor, which comprises a first catalyst including alumina loaded with silver. The NOx-reduced exhaust stream from the first catalyst is then directed to a second catalyst including zirconia loaded with at least one metal.Type: ApplicationFiled: July 10, 2013Publication date: February 13, 2014Applicant: EXXONMOBIL RESEARCH AND ENGINEERING COMPANYInventors: Ajit B. DANDEKAR, Richard F. SOCHA, Richard L. ECKES, S. Beau WALDRUP
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Publication number: 20140041363Abstract: Methods and systems are provided for selective catalytic reduction of NOx with a low molecular low molecular weight aldehyde, e.g., acetaldehyde, as a reductant using a catalyst system including two catalysts. An exhaust stream containing an amount of NO from a combustion operation is provided. A portion of the exhaust stream is introduced to a first catalyst to convert the NO to NO2. The exhaust stream from the first catalyst with NO2 and a reductant stream containing a low molecular weight aldehyde, e.g., acetaldehyde, are introduced to the second catalyst to convert the NO2 to N2. The first catalyst can be bulk Co3O4, Ru or Pt loaded on alumina; the second catalyst can be various zeolites, or zeolites loaded with potassium.Type: ApplicationFiled: July 10, 2013Publication date: February 13, 2014Applicant: EXXONMOBIL RESEARCH AND ENGINEERING COMPANYInventors: Ajit B. DANDEKAR, Richard F. SOCHA, Richard L. ECKES, S. Beau WALDRUP, Jason M. McMULLAN
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Publication number: 20130264246Abstract: Provided are high viscosity high quality Group II lube base stocks with improved properties produced by an integrated hydrocracking and dewaxing process. In one form, the Group II lube base stock includes greater than or equal to 90 wt. % saturates, and less than 10 wt. % aromatics, and has an aromatic performance ratio between 1.0 and 5.0. Also provided are lubricant formulations including the high viscosity high quality Group II lube base stock.Type: ApplicationFiled: March 14, 2013Publication date: October 10, 2013Applicant: ExxonMobil Research and Engineering CompanyInventors: Gretchen L. Holtzer, Ajit B. Dandekar, Charles L. Baker, Bradley R. Fingland, Bryan E. Hagee, Cathleen Yung, Frank C. Wang, Eugenio Sanchez, Rugved Prakash Pathare
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Publication number: 20130026070Abstract: This invention relates to hydrocracking catalysts utilizing stabilized aggregates of small primary crystallites of zeolite Y that are clustered into larger secondary particles. At least 80% of the secondary particles may comprise at least 5 primary crystallites. The size of the primary crystallites may be at most about 0.5 micron, or at most about 0.3 micron, and the size of the secondary particles may be at least about 0.8 micron, or at least about 1.0 ?m. The silica to alumina ratio of the resulting stabilized aggregated Y zeolite may be 4:1 or more. This invention also relates to the use of such catalysts in hydrocracking processes for the conversion of heavy oils into lighter fuel products. The invention is particularly suited for the selective production of diesel range products from gas oil range feedstock materials under hydrocracking conditions.Type: ApplicationFiled: March 6, 2012Publication date: January 31, 2013Applicant: ExxonMobil Research and Engineering CompanyInventors: Christopher G. Oliveri, Wenyih Frank Lai, Ajit B. Dandekar, Scott J. Weigel, Jason Wu, Robert E. Kay
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Patent number: 8263517Abstract: Catalysts for dewaxing of hydrocarbon feeds, particularly feeds with elevated sulfur and nitrogen levels, are provided. The dewaxing catalysts include a zeolite with a low silica to alumina ratio combined with a low surface binder, or alternatively the formulated catalyst has a high ratio of zeolite surface area to external surface area.Type: GrantFiled: December 18, 2008Date of Patent: September 11, 2012Assignee: ExxonMobil Research and Engineering CompanyInventors: Christine N. Elia, Mohan Kalyanaraman, Lei Zhang, Madhav Acharya, Michael A. Daage, Darden Sinclair, Jocelyn A. Kowalski, Jose G. Santiesteban, Ajit B. Dandekar
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Patent number: 7951986Abstract: Disclosed herein is a process and catalyst for producing an ethylbenzene feed from a polyethylbenzene feed, comprising the step of contacting a benzene feed with a polyethylbenzene feed under at least partial liquid phase conditions in the presence of a zeolite beta catalyst having a phosphorus content in the range of 0.01 wt. % to 0.5 wt. % of said catalyst, to provide a product which comprises ethylbenzene.Type: GrantFiled: July 29, 2010Date of Patent: May 31, 2011Assignee: ExxonMobil Chemical Patents Inc.Inventors: Michael C. Clark, Jane C. Cheng, Ajit B. Dandekar
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Patent number: 7868215Abstract: A process for producing cumene is provided which comprises the step of contacting benzene and propylene under at least partial liquid phase alkylating conditions with a particulate molecular sieve alkylation catalyst, wherein the particles of said alkylation catalyst have a surface to volume ratio of about 80 to less than 200 inch?1.Type: GrantFiled: November 10, 2009Date of Patent: January 11, 2011Assignee: ExxonMobil Chemical Patents Inc.Inventors: Ajit B. Dandekar, Michael Hryniszak, David Lawrence Stern
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Publication number: 20100298617Abstract: Disclosed herein is a process and catalyst for producing an ethylbenzene feed from a polyethylbenzene feed, comprising the step of contacting a benzene feed with a polyethylbenzene feed under at least partial liquid phase conditions in the presence of a zeolite beta catalyst having a phosphorus content in the range of 0.01 wt. % to 0.5 wt. % of said catalyst, to provide a product which comprises ethylbenzene.Type: ApplicationFiled: July 29, 2010Publication date: November 25, 2010Inventors: Michael C. Clark, Jane C. Cheng, Ajit B. Dandekar
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Patent number: 7795487Abstract: Disclosed herein is a process and catalyst for producing a monoalkylated aromatic compound from a polyalkylated aromatic compound, comprising the step of contacting an alkylatable aromatic compound with a polyalkylated aromatic compound under at least partial liquid phase conditions in the presence of a zeolite beta catalyst having a phosphorus content in the range of 0.001 wt. % to 10.0 wt. % of said catalyst, to provide a product which comprises a monoalkylated aromatic compound.Type: GrantFiled: February 27, 2006Date of Patent: September 14, 2010Assignee: ExxonMobil Chemical Patents Inc.Inventors: Michael C. Clark, Jane C. Cheng, Ajit B. Dandekar
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Publication number: 20100056835Abstract: A process for producing cumene is provided which comprises the step of contacting benzene and propylene under at least partial liquid phase alkylating conditions with a particulate molecular sieve alkylation catalyst, wherein the particles of said alkylation catalyst have a surface to volume ratio of about 80 to less than 200 inch?1.Type: ApplicationFiled: November 10, 2009Publication date: March 4, 2010Inventors: Ajit B. Dandekar, Michael Hryniszak, David Lawrence Stern
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Patent number: 7671248Abstract: A process for producing sec-butylbenzene comprises contacting a feed comprising benzene and ethylene under alkylation conditions with catalyst comprising (i) a molecular sieve having an X-ray diffraction pattern including d-spacing maxima at 12.4±0.25, 6.9±0.15, 3.57±0.07 and 3.42±0.07 Angstrom and (ii) at least one metal selected from Group 10 of the Periodic Table of Elements to produce an alkylation effluent comprising sec-butylbenzene.Type: GrantFiled: August 5, 2005Date of Patent: March 2, 2010Assignee: ExxonMobil Chemical Patents Inc.Inventors: Ajit B. Dandekar, John P. McWilliams, Thomas Francis Degnan, Jr., Michael Hryniszak
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Patent number: 7638668Abstract: A process for producing cumene is provided which comprises the step of contacting benzene and propylene under at least partial liquid phase alkylating conditions with a particulate molecular sieve alkylation catalyst, wherein the particles of said alkylation catalyst have a surface to volume ratio of about 80 to less than 200 inch?1.Type: GrantFiled: October 22, 2007Date of Patent: December 29, 2009Assignee: ExxonMobil Chemical Patents Inc.Inventors: Ajit B. Dandekar, Michael Hryniszak, David Lawrence Stern
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Patent number: 7569739Abstract: The present invention provides a process for producing an alkylaromatic compound comprising the step of contacting an alkylatable aromatic compound with an alkylating agent under alkylation conditions in the presence of a alkylation catalyst comprising phosphorus and a porous crystalline inorganic oxide material having an X-ray diffraction pattern including the d-spacing maxima at 12.4±0.25, 6.9±0.15, 3.57±0.07 and 3.42±0.07 Angstrom.Type: GrantFiled: October 17, 2007Date of Patent: August 4, 2009Assignee: ExxonMobil Chemical Patents Inc.Inventors: Ajit B. Dandekar, John P. McWilliams, Thomas Francis Degnan, Michael Hryniszak, Donald J. Klocke, Wieslaw Jerzy Roth
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Publication number: 20090186754Abstract: Catalysts for dewaxing of hydrocarbon feeds, particularly feeds with elevated sulfur and nitrogen levels, are provided. The dewaxing catalysts include a zeolite with a low silica to alumina ratio combined with a low surface binder, or alternatively the formulated catalyst has a high ratio of zeolite surface area to external surface area.Type: ApplicationFiled: December 18, 2008Publication date: July 23, 2009Inventors: Christine Elia, Mohan Kalyanaraman, Lei Zhang, Madhav Acharya, Michael A. Daage, Darden Sinclair, Jocelyn A. Kowalski, Jose G. Santiesteban, Ajit B. Dandekar
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Patent number: 7525002Abstract: A process for the production of high octane number gasoline from light refinery olefins, typically from the catalytic cracking unit, and benzene-containing aromatic streams such as reformate. A portion of the light olefins including ethylene and propylene is polymerized to form a gasoline boiling range product and another portion is used to alkylate the light aromatic stream. The alkylation step may be carried out in successive stages with an initial low temperature stage using a catalyst comprising an MWW zeolite followed by a higher temperature stage using a catalyst comprising an intermediate pore size zeolite such as ZSM-5. Using this staged approach, the alkylation may be carried out in the vapor phase. Alternatively, the alkylation may be carried out in the liquid phase using the heavier olefins (propylene, butene) dissolved into the aromatic stream by selective countercurrent extraction; a separate alkylation step using the ethylene not taken up in the extraction is carried out at a higher temperature.Type: GrantFiled: February 27, 2006Date of Patent: April 28, 2009Assignee: ExxonMobil Research and Engineering CompanyInventors: Benjamin S. Umansky, Michael C. Clark, Ajit B. Dandekar
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Patent number: 7498474Abstract: A process for the production of high octane number gasoline from light refinery olefins and benzene-containing aromatic streams such as reformate. The process achieves good utilization of both the ethylene and the propylene present in the mixed olefin feed from the unsaturated gas plant while reducing gasoline benzene levels. The light olefins including ethylene and propylene are reacted with the light aromatic stream containing benzene and other single ring aromatic compounds to form a gasoline boiling range product containing akylaromatics. The reaction is carried out with a two-catalyst system which comprises a member of the MWW family of zeolites and an intermediate pore size zeolite such as ZSM-5 using a fixed catalyst bed in both stages. Use of the two catalyst system enables the conversion of the ethylene and propylene components of the olefin feed to be converted to alkylaromatics under favorable conditions.Type: GrantFiled: February 27, 2006Date of Patent: March 3, 2009Assignee: Exxonmobil Research and Engineering CompanyInventors: Benjamin S. Umansky, Michael C. Clark, Ajit B. Dandekar, Christine N. Elia
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Patent number: 7399894Abstract: A process for producing cumene is provided which comprises the step of contacting benzene and propylene under at least partial liquid phase alkylating conditions with a particulate molecular sieve alkylation catalyst, wherein the particles of said alkylation catalyst have a surface to volume ratio of about 80 to less than 200 inch?1.Type: GrantFiled: March 24, 2005Date of Patent: July 15, 2008Assignee: ExxonMobil Chemical Patents Inc.Inventors: Ajit B. Dandekar, Michael N M N Hryniszak, David Lawrence Stern
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Publication number: 20080167508Abstract: Disclosed herein is a process and catalyst for producing a monoalkylated aromatic compound from a polyalkylated aromatic compound, comprising the step of contacting an alkylatable aromatic compound with a polyalkylated aromatic compound under at least partial liquid phase conditions in the presence of a zeolite beta catalyst having a phosphorus content in the range of 0.001 wt. % to 10.0 wt. % of said catalyst, to provide a product which comprises a monoalkylated aromatic compound.Type: ApplicationFiled: February 27, 2006Publication date: July 10, 2008Inventors: Michael C. Clark, Jane C. Cheng, Ajit B. Dandekar
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Publication number: 20080154082Abstract: A process for producing sec-butylbenzene comprises contacting a feed comprising benzene and ethylene under alkylation conditions with catalyst comprising (i) a molecular sieve having an X-ray diffraction pattern including d-spacing maxima at 12.4±0.25, 6.9±0.15, 3.57±0.07 and 3.42±0.07 Angstrom and (ii) at least one metal selected from Group 10 of the Periodic Table of Elements to produce an alkylation effluent comprising sec-butylbenzene.Type: ApplicationFiled: August 5, 2005Publication date: June 26, 2008Applicant: EXXONMOBIL CHEMICAL PATENTS INC.Inventors: Ajit B. Dandekar, John P. McWilliams, Thomas Francis Degnan, Michael Hryniszak
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Publication number: 20080029435Abstract: A method of rejuvenating a deactivated molecular sieve catalyst, deactivated by use in an olefin oligomerization or aromatics alkylation process, which method comprises contacting the deactivated catalyst with a stream of rejuvenation gas comprising a hydrocarbon product fraction from the process at an elevated temperature and pressure for a time sufficient to effect an increase in catalytic activity of the deactivated catalyst.Type: ApplicationFiled: June 19, 2007Publication date: February 7, 2008Applicant: ExxonMobil Research and Engineering CompanyInventors: Benjamin S. Umansky, Ajit B. Dandekar, Tomas R. Melli, Amanda K. Miller, Ronald D. McGihon