Patents by Inventor Ashim Kumar Ghosh
Ashim Kumar Ghosh 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: 20080176736Abstract: A zeolite catalyst is prepared by treating a zeolite with a phosphorus compound to form a phosphorus-treated zeolite. The phosphorus-treated zeolite is heated to a temperature of about 300° C. or higher and combined with an inorganic oxide binder material to form a zeolite-binder mixture. The zeolite-binder mixture is heated to a temperature of about 400° C. or higher to form a bound zeolite catalyst. The bound zeolite may exhibit at least two 31P MAS NMR peaks with maxima at from about 0 to about ?55 ppm, with at least one peak having a maximum at from about ?40 to about ?50 ppm. Zeolites containing 10-oxygen ring pores that have been prepared in such a way may be used in aromatic alkylation by contacting the bound zeolite catalyst with an aromatic alkylation feed of an aromatic compound and an alkylating agent under reaction conditions suitable for aromatic alkylation.Type: ApplicationFiled: March 25, 2008Publication date: July 24, 2008Applicant: Saudi Basic Industries CorporationInventors: Ashim Kumar Ghosh, Neeta Kulkarni, Pamela Harvey
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Patent number: 7399727Abstract: A catalyst is formed from a phosphorus-containing ZSM-5-type zeolite. The ZSM-5-type zeolite has a silica/alumina molar ratio of at least 200. The phosphorus-containing ZSM-5-type zeolite also has a phosphorus content of at least 8% by weight of zeolite and has multiple phosphorus species exhibited by at least two 31P MAS NMR peaks with maxima at from about 0 to about ?50 ppm. The catalyst may be used in aromatic alkylation by contacting the catalyst with a feed of an aromatic hydrocarbon and an alkylating agent under reaction conditions suitable for aromatic alkylation.Type: GrantFiled: May 25, 2005Date of Patent: July 15, 2008Assignee: Saudi Basic Industries CorporationInventors: Ashim Kumar Ghosh, Neeta Kulkarni, Pamela Harvey
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Patent number: 7368410Abstract: A zeolite catalyst is prepared by treating a zeolite with a phosphorus compound to form a phosphorus-treated zeolite. The phosphorus-treated zeolite is heated to a temperature of about 300° C. or higher and combined with an inorganic oxide binder material to form a zeolite-binder mixture. The zeolite-binder mixture is heated to a temperature of about 400° C. or higher to form a bound zeolite catalyst. The bound zeolite may exhibit at least two 31P MAS NMR peaks with maxima at from about 0 to about ?55 ppm, with at least one peak having a maximum at from about ?40 to about ?50 ppm. Zeolites containing 10-oxygen ring pores that have been prepared in such a way may be used in aromatic alkylation by contacting the bound zeolite catalyst with an aromatic alkylation feed of an aromatic compound and an alkylating agent under reaction conditions suitable for aromatic alkylation.Type: GrantFiled: August 3, 2005Date of Patent: May 6, 2008Assignee: Saudi Basic Industries CorporationInventors: Ashim Kumar Ghosh, Neeta Kulkarni, Pamela Harvey
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Patent number: 7304194Abstract: A method of treating a ZSM-5-type zeolite catalyst is carried out by treating a ZSM-5 zeolite catalyst having a silica/alumina mole ratio of at least about 200 with a phosphorus compound. The phosphorus-treated ZSM-5 zeolite catalyst is calcined and steamed. Steaming of the catalyst is carried out at a temperature of less than about 300° C. The phosphorus-treated ZSM-5 zeolite catalyst has less than 0.05% by weight of the catalyst of any other element other than phosphorus provided from any treatment of the ZSM-5 zeolite with a compound containing said other element. The catalyst may be used in aromatic alkylation by contacting the catalyst with feed of an aromatic hydrocarbon and an alkylating agent within a reactor under reactor conditions suitable for aromatic alkylation. Water cofeed may be introduced water into the reactor during the aromatic alkylation reaction.Type: GrantFiled: May 5, 2005Date of Patent: December 4, 2007Assignee: Saudi Basic Industries CorporationInventors: Ashim Kumar Ghosh, Neeta Kulkarni, Pamela Harvey, Roncalli J. Twomey
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Patent number: 7285511Abstract: A method of modifying a zeolite catalyst to increase para-xylene selectivity of the zeolite catalyst in toluene methylation reactions is provided. The method includes forming a slurry of a ZSM-5-type zeolite and an aqueous solution of a phosphorus compound. Water is removed from the slurry to provide a non-steamed, phosphorus treated ZSM-5 zeolite catalyst without deposition of phosphorus onto the catalyst by organophosphorus vapor deposition. The resulting non-steamed, phosphorus treated ZSM-5 zeolite catalyst has a pore volume of from 0.2 ml/g or less and provides greater than 80% para-xylene selectivity of mixed xylenes when used in toluene methylation.Type: GrantFiled: April 23, 2004Date of Patent: October 23, 2007Assignee: Saudi Basic Industries CorporationInventors: Ashim Kumar Ghosh, Gopalakrishnan Juttu, Pamela Harvey, Neeta Kulkarni
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Patent number: 7279608Abstract: A method of converting methanol to a xylene product is achieved by providing a reactor containing a non-steamed, phosphorus-treated ZSM-5-type zeolite catalyst. The catalyst is contacted with a toluene/methanol feed under reactor conditions suitable for the methylation of toluene. Water cofeed is introduced into the reactor during the methylation reaction under conditions that provide substantially no structural aluminum loss of the catalyst from such introduction of water to provide a selectivity for methanol of at least 40%.Type: GrantFiled: May 12, 2005Date of Patent: October 9, 2007Assignee: Saudi Basic Industries CorporationInventors: Ashim Kumar Ghosh, Neeta Kulkarni, Pamela Harvey
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Patent number: 7244869Abstract: A catalyst for use in aromatic alkylation, such as toluene alkylation with methanol, is comprised of a zeolite with pore size from about 5.0 to about 7.0 ? containing a hydrogenating metal. The catalyst may be used in preparing an alkyl aromatic product by providing the catalyst within a reactor. The catalyst may be contacted with an aromatic hydrocarbon and an alkylating agent in the presence of hydrogen under reaction conditions suitable for aromatic alkylation. The catalyst may also be treated to further increase its stability. This is accomplished by heating the hydrogenating metal loaded zeolite catalyst in the presence of a reducing agent prior to use in an aromatic alkylation reaction to a temperature of from about 400° C. to about 500° C. for about 0.5 to about 10 hours.Type: GrantFiled: March 7, 2006Date of Patent: July 17, 2007Assignee: Saudi Basic Industries CorporationInventors: Ashim Kumar Ghosh, Gopalakrishnan Juttu, Pamela Harvey
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Patent number: 7196237Abstract: A method of modifying a zeolite catalyst to increase selectivity of the catalyst is achieved by dissolving alumina in a phosphorus-containing acid solution, and treating the zeolite catalyst with the dissolved alumina solution. A method of preparing an aromatic product, such as a xylene product, is also achieved by contacting the modified zeolite catalyst with an aromatic hydrocarbon, such as toluene, and an alkylating agent, such as methanol, under reaction conditions suitable for aromatic alkylation. For xylene products the aromatic hydrocarbon may be toluene and the reaction conditions may be suitable for at least one of toluene methylation and transalkylation.Type: GrantFiled: May 20, 2005Date of Patent: March 27, 2007Assignee: Saudi Basic Industries CorporationInventors: Ashim Kumar Ghosh, Pamela Harvey
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Patent number: 7105713Abstract: A method of modifying a ZSM-5-type zeolite catalyst to increase selectivity of the catalyst for para-isomers in aromatic alkylation reactions is provided. The method includes contacting a ZSM-5-type zeolite catalyst with a fluoride-containing compound. The fluoride-containing zeolite catalyst can be used in aromatic alkylation to provide di-alkyl aromatic products. A method of preparing a xylene product is also accomplished by providing a fluoride-treated ZSM-5-type zeolite catalyst within a reactor. The fluoride-treated ZSM-5 zeolite catalyst is contacted with a toluene/methanol feed under reaction conditions conditions suitable for toluene methylation to form a xylene product containing at least 50% para-xylene by total mixed xylenes.Type: GrantFiled: June 8, 2005Date of Patent: September 12, 2006Assignee: Saudi Basic Industries CorporationInventors: Ashim Kumar Ghosh, Pamela Harvey
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Patent number: 7084318Abstract: A method of preparing a xylene product is carried out in a reactor containing a phosphorus-treated ZSM-5-type zeolite catalyst. The method includes initiating a unique start-up of a toluene methylation reaction by contacting the catalyst with a toluene/methanol feed and a cofeed of hydrogen introduced into the reactor at certain start-up conditions. By utilizing the start-up conditions high selectivity for p-xylene can be achieved while providing stable catalytic activity over extended periods.Type: GrantFiled: August 1, 2003Date of Patent: August 1, 2006Assignee: Saudi Basic Industries CorporationInventors: Ashim Kumar Ghosh, Pamela Harvey
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Patent number: 7060864Abstract: A method of preparing a xylene product is carried out by providing a reactor containing a non-steamed, phosphorus-treated ZSM-5-type zeolite catalyst. The catalyst is contacted with a toluene/methanol feed and a cofeed of hydrogen under reactor conditions suitable for the methylation of toluene. Water is introducing into the reactor during the methylation reaction under conditions that provide substantially no structural aluminum loss of the catalyst from such introduction of water.Type: GrantFiled: September 30, 2003Date of Patent: June 13, 2006Assignee: Saudi Basic Industries CorporationInventors: Ashim Kumar Ghosh, Pamela Harvey
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Patent number: 7060644Abstract: A catalyst for use in aromatic alkylation, such as toluene alkylation with methanol, is comprised of a zeolite with pore size from about 5.0 to about 7.0 ? containing a hydrogenating metal. The catalyst may be used in preparing an alkyl aromatic product by providing the catalyst within a reactor. The catalyst may be contacted with an aromatic hydrocarbon and an alkylating agent in the presence of hydrogen under reaction conditions suitable for aromatic alkylation. The catalyst may also be treated to further increase its stability. This is accomplished by heating the hydrogenating metal loaded zeolite catalyst in the presence of a reducing agent prior to use in an aromatic alkylation reaction to a temperature of from about 400° C. to about 500 ° C. for about 0.5 to about 10 hours.Type: GrantFiled: January 8, 2004Date of Patent: June 13, 2006Assignee: Saudi Basic Industries CorporationInventors: Ashim Kumar Ghosh, Gopalakrishnan Juttu, Pamela Harvey
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Patent number: 6943131Abstract: A method of modifying a zeolite catalyst to increase selectivity of the catalyst is achieved by dissolving alumina in a phosphorus-containing acid solution, and treating the zeolite catalyst with the dissolved alumina solution. A method of preparing an aromatic product, such as a xylene product, is also achieved by contacting the modified zeolite catalyst with an aromatic hydrocarbon, such as toluene, and an alkylating agent, such as methanol, under reaction conditions suitable for aromatic alkylation. For xylene products the aromatic hydrocarbon may be toluene and the reaction conditions may be suitable for at least one of toluene methylation and transalkylation.Type: GrantFiled: March 2, 2004Date of Patent: September 13, 2005Assignee: Saudi Basic Industries CorporationInventors: Ashim Kumar Ghosh, Pamela Harvey
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Patent number: 6268305Abstract: Ethylbenzene is produced by alkylation over monoclinic silicalite catalysts having a weak acid site concentration of less than 50 micromoles per gram. A Feed stock containing benzene and ethylene is applied to an alkylation reaction zone having at least one catalyst bed containing a monoclinic silicalite catalyst having a weak acid site concentration of less than 50 micromoles per gram. The alkylation reaction zone is operated at temperature and pressure conditions in which the benzene is in a gaseous phase to cause gas-phase alkylation of the aromatic substrate in the presence of the silicalite catalysts to produce an alkylation product. The alkylation product is then withdrawn from the reaction zone for separation and recovery.Type: GrantFiled: April 6, 2000Date of Patent: July 31, 2001Assignee: Fina Technology, Inc.Inventors: James R. Butler, Ashim Kumar Ghosh
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Patent number: 6222084Abstract: Process for the production of ethylbenzene by alkylation over a silicalite alkylation catalyst with subsequent transalkylation of diethylbenzene with the alkylation catalyst and conditions selected to retard xylene production and also heavies production. Benzene and ethylene are applied to a multi-stage alkylation reaction zone having a plurality of series-connected catalyst beds containing silicalite of a predominantly monoclinic symmetry having a silica/alumina ratio of at least 275. Gas-phase ethylation of benzene is at a flow rate to provide a space velocity of benzene over the catalyst to produce a xylene concentration of about 600 ppm or less of the ethylbenzene content. Periodically the space velocity may be increased to a value which is greater than the space velocity associated with a minimum concentration of diethylbenzene in the alkylation product such that diethylbenzene production is enhanced while minimizing any attendant transalkylation reactions within the alkylation reaction zone.Type: GrantFiled: April 9, 1999Date of Patent: April 24, 2001Assignee: Fina Technology, Inc.Inventors: Ashim Kumar Ghosh, James T. Merrill, James R. Butler
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Patent number: 6096938Abstract: An improved zeolite catalyst having enhanced dealkylation activity is provided. The catalyst is prepared by incorporating fluorine into the zeolite structure. In another embodiment, a transition element such as nickel is additionally incorporated into the zeolite structure. The process for producing the catalyst also includes ion-exchange and calcining steps. A mordenite type catalyst has been found to be particularly effective. The catalyst of the present invention demonstrates improved activity for the dealkylation of polyalkylaromatic compounds found in residue from the alkylation process and in heavy reformate streams from refineries. A dealkylation process using the catalyst of the present invention is provided. The dealkylation process shows good selectivity for benzene and monoalkylated aromatic products, and catalyst stability, particularly at high reaction temperatures.Type: GrantFiled: November 10, 1999Date of Patent: August 1, 2000Assignee: Fina Technology, Inc.Inventor: Ashim Kumar Ghosh
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Patent number: 6090991Abstract: Ethylbenzene is produced by alkylation over monoclinic silicalite catalysts having a weak acid site concentration of less than 50 micromoles per gram. A feedstock containing benzene and ethylene is applied to an alkylation reaction zone having at least one catalyst bed containing a monoclinic silicalite catalyst having a weak acid site concentration of less than 50 micromoles per gram. The alkylation reaction zone is operated at temperature and pressure conditions in which the benzene is in a gaseous phase to cause gas-phase alkylation of the aromatic substrate in the presence of the silicalite catalysts to produce an alkylation product. The alkylation product is then withdrawn from the reaction zone for separation and recovery.Type: GrantFiled: February 27, 1999Date of Patent: July 18, 2000Assignee: Fina Technology, Inc.Inventors: James R. Butler, Ashim Kumar Ghosh
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Patent number: 6057485Abstract: Ethylbenzene is produced by alkylation over a split load of monoclinic silicalite alkylation catalysts having different silica/alumina ratios. A feedstock containing benzene and ethylene is applied to a multi-stage alkylation reaction zone having a plurality of series-connected catalyst beds. At least one catalyst bed contains a first monoclinic silicalite catalyst having a silica/alumina ratio of at least 275. At least one other catalyst bed contains a second monoclinic silicalite catalyst having a silica/alumina ratio of less than about 275. The alkylation reaction zone is operated at temperature and pressure conditions in which the benzene is in a gaseous phase to cause gas-phase alkylation of the aromatic substrate in the presence of the monoclinic silicalite catalysts to produce an alkylation product. The alkylation product is then withdrawn from the reaction zone for separation and recovery.Type: GrantFiled: November 17, 1998Date of Patent: May 2, 2000Assignee: Fina Technology, Inc.Inventors: James T. Merrill, James R. Butler, Ashim Kumar Ghosh
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Patent number: 5990031Abstract: An improved zeolite catalyst having enhanced dealkylation activity is provided. The catalyst is prepared by incorporating fluorine into the zeolite structure. In another embodiment, a transition element such as nickel is additionally incorporated into the zeolite structure. The process for producing the catalyst also includes ion-exchange and calcining steps. A mordenite type catalyst has been found to be particularly effective. The catalyst of the present invention demonstrates improved activity for the dealkylation of polyalkylaromatic compounds found in residue from the alkylation process and in heavy reformate streams from refineries. A dealkylation process using the catalyst of the present invention is provided. The dealkylation process shows good selectivity for benzene and monoalkylated aromatic products, and catalyst stability, particularly at high reaction temperatures.Type: GrantFiled: November 26, 1996Date of Patent: November 23, 1999Assignee: Fina Technology, Inc.Inventor: Ashim Kumar Ghosh
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Patent number: 5907073Abstract: A process for the alkylation of an aromatic substrate over a molecular sieve zeolite catalyst involving supplying an aromatic substrate to a reaction zone containing the catalyst. The molecular sieve catalyst is an effective aromatic alkylation catalyst and comprises a modified zeolite beta alkylation catalyst having an intergrowth of a ZSM-12 crystalline framework within the crystalline framework of zeolite beta. An alkylating agent is also supplied to the reaction zone which is operated under temperature and pressure conditions effective to cause alkylation of the aromatic substrate by the alkylating agent. An alkylated substrate is recovered from the reaction zone.Type: GrantFiled: February 24, 1998Date of Patent: May 25, 1999Assignee: Fina Technology, Inc.Inventor: Ashim Kumar Ghosh