Patents by Inventor Sriram Ramani
Sriram Ramani 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: 6831204Abstract: A new family of oxidative dehydrogenation catalysts having MCrAlY supports can be used in the production of olefins. Olefins are produced by heating a feed stream comprising at least an alkane and an oxidant to a temperature between 25° C. and 800° C.; contacting the feed stream with a catalyst comprising an MCrAlY structure and, optionally, a Group VIII promoter metal coating, wherein M is a base metal, or combination of base metals; and maintaining a contact time of the alkane with the catalyst of less than 200 milliseconds under conditions sufficient to achieve oxidative dehydrogenation of the alkane. M may comprise a metal selected from the group consisting of Group IB-VIIB metals, Group IIIA-VA metals, lanthanide metals, iron, cobalt, nickel, and combinations thereof. More particularly, M may comprise a metal selected from the group consisting Tb, Sm, Pr, Fe, Ni, Co, and combinations thereof.Type: GrantFiled: October 11, 2002Date of Patent: December 14, 2004Assignee: ConocoPhillips CompanyInventors: Zhen Chen, Sriram Ramani, Lisa M. Carmichael, Joe D. Allison
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Patent number: 6800269Abstract: An apparatus and process for recovering elemental sulfur from a H2S-containing waste gas stream are disclosed, along with a method of making a preferred catalyst for catalyzing the process. The apparatus preferably comprises a short contact time catalytic partial oxidation reactor, a cooling zone, and a sulfur condenser. According to a preferred embodiment of the process, a mixture of H2S and O2 contacts the catalyst very briefly (i.e, less than about 200 milliseconds). Some preferred catalyst devices comprise a reduced metal such as Pt, Rh, or Pt—Rh, and a lanthanide metal oxide, or a pre-carbided form of the metal. The preferred apparatus and process are capable of operating at superatmospheric pressure and improve the efficiency of converting H2S to sulfur, which will reduce the cost and complexity of construction and operation of a sulfur recovery plant used for waste gas cleanup.Type: GrantFiled: December 18, 2001Date of Patent: October 5, 2004Assignee: Conocophillips CompanyInventors: Alfred E. Keller, Sriram Ramani, Joe D. Allison, Terry D. Pruitt
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Publication number: 20040176656Abstract: Catalysts and methods useful for the production of olefins from alkanes via oxidative dehydrogenation (ODH) are disclosed. The ODH catalysts include a base metal selected from the group consisting of lanthanide metals, their oxides, and combinations thereof. The base metal is more preferably selected from the group consisting of samarium, cerium, praseodymium, terbium, their corresponding oxides and combinations thereof. The base metal loading is preferably between about 0.5 and about 20 weight percent and more preferably between about 2 and about 10 weight percent. Optionally, the ODH catalysts are further comprised of a Group VIII promoter metal present at trace levels. The Group VIII promoter metal is preferably platinum, palladium or a combination thereof and is preferably present at a promoter metal loading of between about 0.005 and about 0.1 weight percent. Optionally, the ODH catalyst is supported on a refractory support.Type: ApplicationFiled: March 23, 2004Publication date: September 9, 2004Applicant: ConocoPhillips CompanyInventors: Joe D. Allison, Sriram Ramani, Zhen Chen, Lisa M. Carmichael, Shang Y. Chen, Steve R. McDonald, Anne Gaffney
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Publication number: 20040158112Abstract: A catalyst useful for the production of olefins from alkanes via oxidative dehydrogenation (ODH) is disclosed. The catalyst includes a silicon carbide support. The catalyst may optionally include a base metal, metal oxide, or combination thereof. A base metal is herein defined as a non-Group VIII metal, with the exception of iron, cobalt and nickel. Suitable base metals include Group IB-VIIB metals, Group IIIA-VA metals, Lanthanide metals, iron, cobalt and nickel. Suitable metal oxides include alumina, stabilized aluminas, zirconia, stabilized zirconias (PSZ), titania, ytteria, silica, niobia, and vanadia. Additionally, the catalyst may optionally include a Group VIII promoter. Suitable Group VIII promoters include Ru, Rh, Pd, Os, Ir, and Pt.Type: ApplicationFiled: February 10, 2003Publication date: August 12, 2004Applicant: ConocoPhillips CompanyInventors: Sriram Ramani, Joe D. Allison, Lisa M. Carmichael, Zhen Chen
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Publication number: 20040157939Abstract: A method for converting light hydrocarbons (e.g. methane or natural gas) to synthesis gas employs a silicon carbide-supported catalyst that catalyzes a net partial oxidation reaction. Certain preferred catalysts include a catalytically active metal disposed on a silicon carbide support.Type: ApplicationFiled: February 10, 2003Publication date: August 12, 2004Applicant: ConocoPhillips CompanyInventors: Sriram Ramani, David M. Minahan, Yi Jiang
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Patent number: 6773691Abstract: A method for generating syngas having a H2:CO ratio of less than 2:1 including selecting a predetermined desired syngas H2:CO molar ratio, selecting a hydrocarbon with a natural H2:CO molar ratio less than the desired ratio, selecting a hydrocarbon with a natural H2:CO molar ratio greater than the desired ratio, mixing the two hydrocarbons such that the natural H2:CO molar ratio of the mixture is the desired ratio, and catalytically partially oxidizing the mixture to produce syngas with the desired ratio.Type: GrantFiled: July 16, 2002Date of Patent: August 10, 2004Assignee: ConocoPhillips CompanyInventors: Sriram Ramani, Joe D. Allison, Alfred E. Keller
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Publication number: 20040142815Abstract: A method is disclosed for converting light hydrocarbons (e.g. methane or natural gas) to synthesis gas employing a nonmicroporous, thin shell catalyst that catalyzes a net partial oxidation reaction. Certain preferred catalysts comprise a thin outer layer comprising at least one catalytically active metal disposed on a discrete nonmicroporous support structure. A preferred thin shell catalyst has an effectiveness factor greater than 0.1 when utilized in a partial oxidation reaction.Type: ApplicationFiled: December 22, 2003Publication date: July 22, 2004Applicant: ConocoPhillips CompanyInventors: Sriram Ramani, Yi Jiang, Harold A. Wright
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Publication number: 20040140245Abstract: A process and catalyst are disclosed for reducing coking in hydrocarbon processing reactions. The preferred embodiments employ a sulfur-containing material such as hydrogen sulfide to reduce catalyst susceptibility to deactivation from carbon deposits formed during processing.Type: ApplicationFiled: January 17, 2003Publication date: July 22, 2004Applicant: ConocoPhillips CompanyInventors: Sriram Ramani, Alfred E. Keller, Joe D. Allison, Zhen Chen
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Publication number: 20040072685Abstract: A catalyst useful for the production of olefins from alkanes via oxidative dehydrogenation (ODH) is disclosed. In accordance with a preferred embodiment of the present invention, a catalyst for use in ODH processes includes a MCrAlY support. M is preferably a base metal, or combination of base metals. A base metal is herein defined as a non-Group VIII metal, with the exception of iron, cobalt and nickel. Suitable base metals include Group IB-VIIB metals, Group IIIA-VA metals, Lanthanide metals, iron, cobalt and nickel. In a preferred embodiment, M is iron. Additionally, the catalyst may optionally include a Group VIII promoter. Suitable Group VIII promoters include Ru, Rh, Pd, Os, Ir, and Pt. In another preferred embodiment, M is a combination of a Lanthanide metal and iron with a front-loaded Group VIII promoter.Type: ApplicationFiled: October 11, 2002Publication date: April 15, 2004Applicant: Conoco Inc.Inventors: Zhen Y. Chen, Sriram Ramani, Lisa M. Carmichael, Joe D. Allison
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Publication number: 20040068148Abstract: Catalysts and methods useful for the production of olefins from alkanes via oxidative dehydrogenation (ODH) are disclosed. The ODH catalysts are comprised of a Group VIII promoter metal present at trace levels. The Group VIII promoter metal is preferably platinum, palladium or a combination thereof and is preferably present at a promoter metal loading of between about 0.005 and about 0.1 weight percent. Optionally, the ODH catalysts include a base metal, metal oxide, or combination thereof. The optional base metal is selected from the group consisting of Group IB-IIB metals, Group IVB-VIIB metals, Group IIA-VA metals, scandium, yttrium, actinium, iron, cobalt, nickel, their oxides, and combinations thereof. The base metal is more preferably selected from the group consisting copper, tin, chromium, gold, manganese and their respective oxides and any combinations thereof. The base metal loading is preferably between about 0.5 and about 10 weight percent.Type: ApplicationFiled: October 8, 2002Publication date: April 8, 2004Applicant: Conoco Inc.Inventors: Joe D. Allison, Sriram Ramani, Zhen Chen, Lisa M. Carmichael, Shang Y. Chen, Steve R. McDonald, Anne Gaffney
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Publication number: 20040068153Abstract: Catalysts and methods useful for the production of olefins from alkanes via oxidative dehydrogenation (ODH) are disclosed. The ODH catalysts include a base metal selected from the group consisting of lanthanide metals, their oxides, and combinations thereof. The base metal is more preferably selected from the group consisting of samarium, cerium, praseodymium, terbium, their corresponding oxides and combinations thereof. The base metal loading is preferably between about 0.5 and about 20 weight percent and more preferably between about 2 and about 10 weight percent. Optionally, the ODH catalysts are further comprised of a Group VIII promoter metal present at trace levels. The Group VIII promoter metal is preferably platinum, palladium or a combination thereof and is preferably present at a promoter metal loading of between about 0.005 and about 0.1 weight percent. Optionally, the ODH catalyst is supported on a refractory support.Type: ApplicationFiled: October 8, 2002Publication date: April 8, 2004Applicant: Conoco Inc.Inventors: Joe D. Allison, Sriram Ramani, Zhen Chen, Lisa M. Carmichael, Shang Y. Chen, Steve R. McDonald, Anne Gaffney
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Publication number: 20040062704Abstract: The present invention includes a process for producing carbon filaments and synthesis gas from a mixture of alkanes, preferably natural gas, comprising converting a first portion of the alkanes, preferably C2+ hydrocarbons, directly to carbon filaments and converting a second portion of the alkanes, preferably methane, to syngas. The natural gas may be separated into a first feed stream comprising ethane, propane, and butane and a second feed stream comprising methane. The first feed stream is fed to a carbon filament CF reactor to produce carbon filaments and hydrogen. The second feed stream is fed to a syngas production reactor to produce syngas. Alternatively, the natural gas is fed to at least one carbon filament reactor that is maintained at an effective temperature to convert C2+ hydrocarbons in the natural gas to carbon filaments and hydrogen, thereby filtering methane from the natural gas.Type: ApplicationFiled: October 1, 2002Publication date: April 1, 2004Applicant: Conoco Inc.Inventors: Joe D. Allison, Sriram Ramani, Priya Rangarajan, Kenneth M. York, Troy L. Amundson, Gary E. Welch
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Publication number: 20040013605Abstract: A method for generating syngas having a H2:CO ratio of less than 2:1 including selecting a predetermined desired syngas H2:CO molar ratio, selecting a hydrocarbon with a natural H2:CO molar ratio less than the desired ratio, selecting a hydrocarbon with a natural H2:CO molar ratio greater than the desired ratio, mixing the two hydrocarbons such that the natural H2:CO molar ratio of the mixture is the desired ratio, and catalytically partially oxidizing the mixture to produce syngas with the desired ratio.Type: ApplicationFiled: July 16, 2002Publication date: January 22, 2004Applicant: Conoco Inc.Inventors: Sriram Ramani, Joe D. Allison, Alfred E. Keller
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Publication number: 20040005270Abstract: A method is disclosed for converting light alkanes (e.g. methane or natural gas) to synthesis gas employing a stabilized Ni-based catalyst that is active for catalyzing the net partial oxidation of the hydrocarbon, in the presence of O2 to CO and H2. Certain preferred catalysts comprise Ni alloyed with a Ni-stabilizing amount of gold or silver, and a lanthanide element, carried on a refractory support.Type: ApplicationFiled: July 2, 2002Publication date: January 8, 2004Applicant: Conoco Inc.Inventors: Bang C. Xu, Sriram Ramani, Sergej A. Maslov
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Publication number: 20030208095Abstract: A catalyst useful for the production of olefins from alkanes via oxidative dehydrogenation (ODH) is disclosed. In accordance with a preferred embodiment of the present invention, a catalyst for use in ODH processes includes a base metal, a promoter metal, and a support comprising a plurality of discrete structures. A base metal is herein defined as a non-Group VIII metal, with the exception of iron, cobalt and nickel. Suitable base metals include Group IB-VIIB metals, Group IIIA-VA metals, Lanthanide metals, iron, cobalt and nickel. Suitable promoter metals include Group VIII metals (i.e. platinum, palladium, ruthenium, rhodium, osmium, and iridium). In some embodiments the support is fabricated from a refractory material. Suitable refractory support materials include alumina, stabilized aluminas, zirconia, stabilized zirconias (PSZ), titania, yttria, silica, niobia, and vanadia.Type: ApplicationFiled: May 6, 2002Publication date: November 6, 2003Inventors: Lisa M. Budin, Joe D. Allison, Sriram Ramani
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Publication number: 20030198592Abstract: Embodiments include a method and apparatus for converting a hydrocarbon and oxygen feed stream to a product stream such as syngas, including multiple serially aligned reaction zones and multiple hydrocarbon feeds. The first reaction zone catalyzes the net partial oxidation of the feed hydrocarbon. The subsequent zones catalyze reactions such as the stream or dry reforming of hydrocarbons or the water gas shift reaction, depending on the stream composition in the vicinity of the zone, and the desired product stream composition.Type: ApplicationFiled: April 19, 2002Publication date: October 23, 2003Applicant: Conoco Inc.Inventors: Joe D. Allison, Sriram Ramani, Daxiang Wang, Tianyan Niu, Yaming Jin, Gloria I. Straguzzi
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Publication number: 20030165424Abstract: A process and catalyst are disclosed for the catalytic partial oxidation of light hydrocarbons to produce synthesis gas at superatmospheric pressures. A preferred catalyst used in the process includes a nickel-magnesium oxide solid solution and at least one promoter chosen from Cr, Mn, Mo, W, Sn, Re, Rh, Ru, Ir, Pt, La, Ce, Sm, Yb, Lu, Bi, Sb, In and P, and oxides thereof, carried on a refractory support.Type: ApplicationFiled: January 9, 2003Publication date: September 4, 2003Applicant: Conoco Inc.Inventors: Sriram Ramani, Joe D. Allison, David M. Minahan, Harold A. Wright
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Publication number: 20030129123Abstract: A process and system for producing synthesis gas by a SPOC™ enhanced catalytic partial oxidation process is disclosed. A reaction in which H2S is partially oxidized to elemental sulfur and water takes place instead of a secondary reaction in which a portion of the light hydrocarbon feed is combusted to form CO2 and water. An increase in yield and selectivity for CO and H2 products results, and readily recoverable elemental sulfur is also produced.Type: ApplicationFiled: December 12, 2002Publication date: July 10, 2003Applicant: Conocophillips CompanyInventors: Sriram Ramani, Alfred E. Keller
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Publication number: 20030129121Abstract: The present invention includes an integrated process for the production of carbon filaments, comprising converting a portion of hydrocarbons to alkenes via oxidative dehydrogenation and further converting a portion of the alkenes to carbon filaments via contact with a metal catalyst. A portion of unconverted hydrocarbons remaining after oxidative dehydrogenation may also be further converted to carbon filaments via contact with the metal catalyst. The conversion of hydrocarbons to alkenes via oxidative dehydrogenation and further conversion of the alkenes and unconverted hydrocarbons to carbon filaments via contact with a metal catalyst may be carried out in the same or separate reactor vessels. A plurality of reactor vessels arranged in parallel may be used for the conversion of the alkenes and unconverted hydrocarbons to carbon filaments.Type: ApplicationFiled: October 1, 2002Publication date: July 10, 2003Applicant: Conoco Inc.Inventors: Joe D. Allison, Lisa M. Carmichael, Larry M. Meyer, Kenneth M. York, Sriram Ramani
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Publication number: 20030119658Abstract: This invention provides a method for recovering rhenium oxide from a material containing rhenium by itself or rhenium in combination with some other element, such as an element catalytically active for a catalytic process, such as hydrogenation, oxidation, reforming, and hydrocracking. The method includes conversion of rhenium to a sublimable oxide via oxidation, heating in an oxidizing atmosphere to sublime the oxide as a volatized oxide, and then isolation of rhenium from the volatized oxide.Type: ApplicationFiled: December 18, 2002Publication date: June 26, 2003Applicant: ConocoPhillips CompanyInventors: Joe D. Allison, Nithya Srinivasan, Sriram Ramani