Patents by Inventor Tamotsu Imai

Tamotsu Imai 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: 6171478
    Abstract: A process for the desulfurization of hydrocarbonaceous oil wherein the hydrocarbonaceous oil is contacted with a hydrodesulfurization catalyst in a hydrodesulfurization reaction zone to reduce the sulfur level to a relatively low level and then contacting the resulting hydrocarbonaceous stream from the hydrodesulfurization zone with an oxidizing agent to convert the residual, low level of sulfur compounds into sulfur-oxidated compounds. The resulting hydrocarbonaceous oil stream containing the sulfur-oxidated compounds is separated after decomposing any residual oxidizing agent to produce a stream containing the sulfur-oxidated compounds and a hydrocarbonaceous oil stream having a reduced concentration of sulfur-oxidated compounds.
    Type: Grant
    Filed: August 2, 1999
    Date of Patent: January 9, 2001
    Assignee: UOP LLC
    Inventors: Carlos A. Cabrera, Tamotsu Imai
  • Patent number: 6048449
    Abstract: A novel catalyst and the use thereof in a reforming process is disclosed. The dual-function catalyst comprises a refractory inorganic oxide, indium, Group IVA(IUPAC 14) metal, and a platinum-group metal concentrated in the surface layer of each catalyst particle. Utilization of this catalyst in the conversion of hydrocarbons, especially in reforming, results in significantly improved selectivity to the desired gasoline or aromatics product.
    Type: Grant
    Filed: October 23, 1998
    Date of Patent: April 11, 2000
    Assignee: UOP LLC
    Inventors: Paula L. Bogdan, Tamotsu Imai
  • Patent number: 6040489
    Abstract: A process for separating 1,3-butadiene from a crude C.sub.4 stream containing butanes, butenes, butadienes and acetylenes has been developed. The process begins with introducing hydrogen, a solvent, and the crude C.sub.4 stream to a catalytic extractive distillation unit having a reaction zone containing a catalyst capable of hydrogenating acetylenes. Butanes and butenes, being less soluble in the solvent, are distilled in an overhead stream from the catalytic extractive distillation unit. Butadienes and acetylenes, being more soluble in the solvent, are carried with the solvent to the reaction zone located within the catalytic extractive distillation unit. In the reaction zone the acetylenes are converted to hydrogenation products. The hydrogenation products other than butadiene are separated from the butadienes by the extractive distillation occurring in the unit. The solvent and butadiene mixture is removed from the catalytic extractive distillation unit in a distillate stream.
    Type: Grant
    Filed: December 9, 1998
    Date of Patent: March 21, 2000
    Assignee: UOP LLC
    Inventor: Tamotsu Imai
  • Patent number: 5858908
    Abstract: A novel catalyst and the use thereof in a reforming process is disclosed. The dual-function catalyst comprises a refractory inorganic oxide, indium, Group IVA(IUPAC 14) metal, and a platinum-group metal concentrated in the surface layer of each catalyst particle. Utilization of this catalyst in the conversion of hydrocarbons, especially in reforming, results in significantly improved selectivity to the desired gasoline or aromatics product.
    Type: Grant
    Filed: April 17, 1997
    Date of Patent: January 12, 1999
    Assignee: UOP LLC
    Inventors: Paula L. Bogdan, Tamotsu Imai
  • Patent number: 5689029
    Abstract: An improved process for the catalytic dehydrogenation of paraffinic hydrocarbons is disclosed. Feed paraffinic hydrocarbons are dehydrogenated by means of contacting the dehydrogenatable hydrocarbon with a dehydrogenation catalyst in a first dehydrogenation zone wherein the endothermic dehydrogenation reaction reduces the temperature of the resulting hydrocarbon stream containing dehydrogenated hydrocarbon compounds. The resulting effluent from the preceding dehydrogenation zone is then contacted with a hot hydrogen-rich gaseous stream having a temperature greater than the hydrocarbon stream to increase the temperature of the hydrocarbon stream and then the resulting heated stream is introduced into a subsequent dehydrogenation zone to produce additional dehydrogenated hydrocarbon compounds.
    Type: Grant
    Filed: December 27, 1995
    Date of Patent: November 18, 1997
    Assignee: UOP
    Inventors: Bipin V. Vora, Tamotsu Imai
  • Patent number: 5672795
    Abstract: An etherification process combines an alkylation zone with a skeletal olefin isomerization zone in an arrangement that rejects isoalkanes and normal alkanes with only minor loss of valuable olefin isomers. The invention also provides a balanced feed to an alkylation zone for the production of high octane gasoline components. This invention can be used to provide ethers and gasoline boiling range alkylates from either C.sub.4 or C.sub.5 feedstocks. The invention fully utilizes all olefin isomers improve octane and vapor pressure charactristics of the gasoline components.
    Type: Grant
    Filed: September 25, 1995
    Date of Patent: September 30, 1997
    Assignee: UOP
    Inventors: Bipin V. Vora, Tamotsu Imai, Peter R. Pujado
  • Patent number: 5491275
    Abstract: An improved process for the catalytic dehydrogenation of paraffinic hydrocarbons is disclosed. Feed paraffinic hydrocarbons are dehydrogenated by means of contacting the dehydrogenatable hydrocarbon with a dehydrogenation catalyst in a first dehydrogenation zone wherein the endothermic dehydrogenation reaction reduces the temperature of the resulting hydrocarbon stream containing dehydrogenated hydrocarbon compounds. The resulting effluent from the first dehydrogenation zone is then contacted with a hot hydrogen-rich gaseous stream having a temperature greater than the hydrocarbon stream to increase the temperature of the hydrocarbon stream and then introducing the resulting heated stream into a second dehydrogenation zone to produce additional dehydrogenated hydrocarbon compounds.
    Type: Grant
    Filed: September 1, 1994
    Date of Patent: February 13, 1996
    Assignee: UOP
    Inventors: Bipin V. Vora, Tamotsu Imai
  • Patent number: 5338889
    Abstract: A combination of an etherification process and a process for the isomerization of linear alkenes to isoalkenes uses an adsorptive separation zone for olefin and paraffin separation upstream of the MTBE unit to reduce olefin losses associated with the rejection of butanes. The location of the MTBE unit downstream of the adsorptive separation zone facilitates the essentially complete removal of isobutane from the process. Supplemental rejection of isobutane downstream of the adsorptive separation permits the use of low purity adsorptive separation zone and also allows the recovery of a high purity butene-1 product.
    Type: Grant
    Filed: December 29, 1992
    Date of Patent: August 16, 1994
    Assignee: UOP
    Inventors: Bipin V. Vora, Tamotsu Imai, Peter J. Pujado
  • Patent number: 5258564
    Abstract: A process for converting C.sub.2 to C.sub.6 aliphatic hydrocarbons to aromatics is described. The process uses a catalyst which contains a zeolite, an aluminum phosphate binder and a gallium component. Examples of zeolites which can be used are the ZSM family of zeolites, with ZSM-5 being a specific example. The catalyst is characterized in that it is tolerant to exposure to hydrogen at temperatures of about 500.degree. to about 700.degree. C. The catalyst's tolerance to hydrogen exposure is the result of treating the catalyst with an aqueous solution of a weakly acidic ammonium salt or a dilute acid solution at a temperature of about 50.degree. to about 100.degree. C. for a time of about 1 to about 48 hours, followed by calcination.
    Type: Grant
    Filed: August 21, 1992
    Date of Patent: November 2, 1993
    Assignee: UOP
    Inventors: Joseph A. Kocal, Tamotsu Imai, Paul J. Kuchar, Christopher D. Gosling
  • Patent number: 5212127
    Abstract: This invention relates to a process for reactivating a dehydrocyclodimerization catalyst. Dehydrocyclodimerization catalysts which contain an aluminum phosphate binder can be deactivated when they are exposed to hydrogen at temperatures above 500.degree. C. The instant process restores substantially all of the catalyst's lost activity. The process involves treating the catalyst with an aqueous solution of a weakly acidic ammonium salt or a dilute acid solution at a temperature of about 50.degree. to about 100.degree. C. for a time of about 1 to about 48 hours. An ammonium nitrate solution is preferred. Next the catalyst is calcined at a temperature of about 500.degree. to about 700.degree. C. for a time of about 1 to about 15 hours to provide a reactivated catalyst. The catalyst can be reactivated several times using this process.
    Type: Grant
    Filed: November 8, 1991
    Date of Patent: May 18, 1993
    Assignee: UOP
    Inventors: Joseph A. Kocal, Christopher D. Gosling, Paul J. Kuchar, Tamotsu Imai
  • Patent number: 5169812
    Abstract: A catalyst for converting C.sub.2 to C.sub.6 aliphatic hydrocarbons to aromatics is described. The catalyst contains a zeolite, an aluminum phosphate binder and a gallium component. Examples of zeolites which can be used are the ZSM family of zeolites, with ZSM-5 being a specific example. The catalyst is characterized in that it is tolerant to exposure to hydrogen at tempertures of about 500.degree. to about 700.degree. C. The catalyst's tolerance to hydrogen exposure is the result of treating the catalyst with an aqueous solution of a weakly acidic ammonium salt or a dilute acid solution at a temperature of about 50.degree. to about 100.degree. C. for a time of about 1 to about 48 hours, followed by calcination. A process for preparing the catalyst is also described.
    Type: Grant
    Filed: September 16, 1991
    Date of Patent: December 8, 1992
    Assignee: UOP
    Inventors: Joseph A. Kocal, Tamotsu Imai, Paul J. Kuchar, Christopher D. Gosling
  • Patent number: 5095161
    Abstract: Methane is upgraded to higher molecular weight hydrocarbons in a process using a novel catalyst comprising oxides of boron, tin and zinc. The feed admixture also comprises oxygen. The novel catalyst may comprise one or more Group I-A or II-A elements, preferably potassium and is characterized by its method of manufacture.
    Type: Grant
    Filed: August 6, 1990
    Date of Patent: March 10, 1992
    Assignee: UOP
    Inventors: Hayim Abrevaya, Tamotsu Imai, Lisa M. Lane
  • Patent number: 5043509
    Abstract: Catalyst particles which are employed in reactions involving the conversion of organic compounds should possess a desired configuration in order to maintain a desired voidage which will permit passage of the feedstock through the catalyst bed during the conversion reaction. Solid phosphoric acid catalysts which comprise an admixture of an acid of phosphorus and a solid binder such as a siliceous material may be formed into polylobular, tubular, ridged, fluted, or channeled cylindrical particles which will permit a sufficient amount of voidage in the catalyst bed to be maintained even though the catalyst particles will swell during the reaction due to the formation of coke on the surface thereof.
    Type: Grant
    Filed: August 18, 1989
    Date of Patent: August 27, 1991
    Assignee: UOP
    Inventors: Tamotsu Imai, Paul T. Barger, Harold U. Hammershaimb
  • Patent number: 5043511
    Abstract: Alkyl aromatic compounds may be prepared by reacting an aromatic compound such as benzene with an alkylating agent such as an olefin or alkyl halide in the presence of an alkylation catalyst. The alkylation catalyst of the present invention comprises a clay which has been coextruded with a multi-valent metal and preferably a metal selected from the group consisting of Groups IIIA, IIIB and IVB of the Periodic Table. The resultant extrudate is then impregnated with a dissimilar multi-valent metal selected from the above named groups followed by calcination to form the desired composite. By utiilzing this catalytic composite in an alkylation reaction it is possible to obtain improved yields of alkyl aromatic compounds which may then be used in the preparation of biodegradable detergents.
    Type: Grant
    Filed: November 13, 1989
    Date of Patent: August 27, 1991
    Assignee: UOP
    Inventors: Tamotsu Imai, Joseph A. Kocal
  • Patent number: 5034118
    Abstract: Hydrogen sulfide can be conveniently removed from streams containing up to about 1,000 ppm of H.sub.2 S by reacting the latter with an olefin using a bed of an acidic solid catalyst in a non-oxidative process for the removal of hydrogen sulfide. The reaction can be effected under relatively mild conditions and is very selective for the removal of hydrogen sulfide without being attended by other unwanted reactions such as oligomerization, disproportionation, and skeletal rearrangement. Levels of hydrogen sulfide in the treated product of no more than about 5 ppm can be readily attained using a broad variety of acidic solid catalysts and unsaturated hydrocarbons, especially olefins.
    Type: Grant
    Filed: September 29, 1989
    Date of Patent: July 23, 1991
    Assignee: UOP
    Inventors: Jeffery C. Bricker, Tamotsu Imai
  • Patent number: 5012027
    Abstract: A novel catalytic composite and a process for its use is disclosed. The catalyst composite comprises a first component selected from Group IA and Group IIA elements of the Periodic Table of the Elements, a second component selected from iridium, and osmium, or mixtures thereof, a third component selected from the elements of Group IVA of the Periodic Table of the Elements, platinum, and a support having a nominal dimension (d) of from 50 to 10,000 microns. The catalytic composite is characterized in that both the second component and platinum are surface-impregnated upon the support, with the concentration gradient of the second component being steeper than that of platinum. The second component is eggshell surface-impregnated.
    Type: Grant
    Filed: November 9, 1989
    Date of Patent: April 30, 1991
    Assignee: UOP
    Inventors: Hayim Abrevaya, Tamotsu Imai
  • Patent number: 5003121
    Abstract: Alkyl aromatic compounds may be prepared by reacting an aromatic compound with an alkylating agent such as an olefin in the presence of an alkylation catalyst. The alkylation catalyst of the present invention comprises a composite which has been prepared by coextruding a clay component and at least one multi-valent metal component in which the metal is selected from the group consisting of Groups IIIA, IIIB and IVB of the Periodic Table, followed by drying the resultant extrudate and calcination thereof. By utilizing a catalyst which has been prepared by this method in an alkylation reaction it is possible to obtain an improved alkylate selectivity.
    Type: Grant
    Filed: August 28, 1989
    Date of Patent: March 26, 1991
    Assignee: UOP
    Inventors: Tamotsu Imai, Joseph A. Kocal
  • Patent number: 4973779
    Abstract: A hydrocarbon conversion process which utilizes a novel catalytic composite is disclosed. The catalyst composite comprises a platinum group metal component, a first modifier selected from Group IA and IIA elements of the Periodic Table, a second modifier component selected from the group of elements consisting of palladium, iridium, and osmium, and a third modifier component selected from the elements of Group IVA of the Periodic Table of the Elements. All of the catalytic components are located on a refractory oxide support having a nominal diameter (d) of from 50 to 10,000 microns. The catalytic composite is characterized in that the second modifier components is surface-impregnated upon the support in such a manner that the average concentration of the surface-impregnated second modifier component on the outside 0.2d micron catalyst layer is at least 2 times the average concentration of the second modifier component in 0.
    Type: Grant
    Filed: November 9, 1989
    Date of Patent: November 27, 1990
    Assignee: UOP
    Inventors: Tamotsu Imai, Hayim Abrevaya
  • Patent number: 4962261
    Abstract: Methane is upgraded to higher molecular weight hydrocarbons in a process using a novel catalyst comprising boron, tin and zinc. The feed admixture also comprises oxygen. The novel catalyst may comprise one or more Group I-A or II-A elements, preferably potassium.
    Type: Grant
    Filed: June 20, 1988
    Date of Patent: October 9, 1990
    Assignee: UOP
    Inventors: Hayim Abrevaya, Tamotsu Imai
  • Patent number: 4886928
    Abstract: A novel dehydrogenation process is disclosed which utilizes a catalyst comprising a platinum group component, a component selected from the group comprising scandium, yttrium, lanthanum, and actinium, a component selected from the group comprising tin, lead, and germanium, less than 0.3 wt. % of a halogen component, and an optional Group IA or IIA component, all on a refractory inorganic oxide support.
    Type: Grant
    Filed: September 26, 1988
    Date of Patent: December 12, 1989
    Assignee: UOP
    Inventors: Tamotsu Imai, Robert J. Schmidt