Patents by Inventor Chwan P. Kyan
Chwan P. Kyan 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: 6287454Abstract: Lubricant oils of low pour point and improved oxidation stability are produced by catalytically dewaxing a lube feedstock over a zeolite dewaxing catalyst such as ZSM-5 in the hydrogen or decationized form. The use of these catalysts enables products of excellent oxidative stability to be obtained and reduces the catalyst aging rate in the first and subsequent dewaxing cycles to values below 5° F./day. The duration of the dewaxing cycles may be extended, particularly in the second and subsequent cycles after hydrogen reactivation.Type: GrantFiled: August 16, 1994Date of Patent: September 11, 2001Assignee: Mobil Oil CorporationInventors: Thomas R. Forbus, Jr., Chwan P. Kyan
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Patent number: 5603824Abstract: The instant invention discloses a process of upgrading a waxy hydrocarbon feed mixture containing sulfur compounds which boils in the distillate range, in order to reduce sulfur content and 85% point while preserving the high octane of naphtha by-products and maximizing distillate yield. The process employs a single, downflow reactor having at least two catalyst beds and an inter-bed redistributor between the beds. The top bed contains a hydrocracking catalyst, preferably zeolite beta, and the bottom bed contains a dewaxing catalyst, preferably ZSM-5. A desulfurization catalyst may be added to either bed depending on sulfur distribution in the feed. The feed is separated into a lighter, lower boiling stream and a heavier, higher boiling stream. The effluent of the top bed cascades without interbed separation to the inter-bed redistributor, where it is recombined with the lighter stream. The recombined stream then enters the bottom bed for dewaxing.Type: GrantFiled: August 3, 1994Date of Patent: February 18, 1997Assignee: Mobil Oil CorporationInventors: Chwan P. Kyan, Paul J. Oswald
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Patent number: 5456820Abstract: A process for making a lubricant oil of low pour point which comprises a) catalytically dewaxing a lube boiling range feedstock in the presence of hydrogen over a dewaxing catalyst comprising an intermediate pore size zeolite in the hydrogen or decationized form during a dewaxing cycle in which the temperature is progressively increased to maintain a substantially constant product pour point to produce a lubricant oil product of improved oxidation stability. The feedstock is sequenced during a dewaxing cycle from a heavy feed to a lighter feed in order to avoid contacting the lighter feed with the catalyst in its most active conditions.Type: GrantFiled: December 23, 1991Date of Patent: October 10, 1995Assignee: Mobil Oil CorporationInventors: Thomas R. Forbus, Jr., David S. Shihabi, Chwan P. Kyan, Robert W. Bortz, Rene B. LaPierre
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Patent number: 5246568Abstract: A process for making a lubricant oil of low pour point and improved oxidation stability by catalytically hydro-dewaxing a lube chargestock containing paraffin wax in a vertical column reactor having a cascade series of fixed downflow catalyst beds over dewaxing catalyst comprising acid medium pore size zeolite. The treatment is carried out by selectively hydrodewaxing paraffinic wax contained in the liquid petroleum in a first serial catalyst bed under adiabatic cracking temperature conditions while controlling adiabatic exothermal heat of reaction within a 30.degree. C. maximum excursion from the initial reaction temperature, thereby producing lighter olefinic components, recovering partially hydrodewaxed liquid petroleum from a bottom portion of the first serial catalyst bed, and redistributing said partially hydrodewaxed liquid petroleum for contact with said catalyst in at least one downstream fixed catalyst bed.Type: GrantFiled: September 5, 1991Date of Patent: September 21, 1993Assignee: Mobil Oil CorporationInventors: Thomas R. Forbus, Chwan P. Kyan
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Patent number: 5053117Abstract: An improved process for catalytically dewaxing low nitrogen content hydrocarbon oils, such as distilled hydrocracker bottoms which normally form by-product naphtha of variable, but poor octane quality. The improvement is achieved by doping the low nitrogen content oil with a small amount of high nitrogen content gas oil, resulting in a by-product naphtha having a clear research octane of about 90, which octane is relatively insensitive to adjustment of pour point during processing.Type: GrantFiled: July 25, 1990Date of Patent: October 1, 1991Assignee: Mobil Oil CorporationInventors: Chwan P. Kyan, Rene B. LaPierre, Hsin-Ju J. Wang
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Patent number: 4923591Abstract: Process for the continuous catalytic dewaxing of lube containing feeds wherein the feed effectively moves countercurrently to the catalyst. The process is based on the discovery that in a two-stage catalytic dewaxing process the stage-two or back-end dewaxing catalyst shows a concave upward aging when it is used to produce a targeted pour point lube, but the back-end dewaxing catalyst can be used as a stage one or front-end dewaxing catalyst to produce an intermediate pour point product.Type: GrantFiled: January 4, 1988Date of Patent: May 8, 1990Assignee: Mobil Oil CorporationInventors: Kenneth R. Graziani, James R. Katzer, Chwan P. Kyan
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Patent number: 4720337Abstract: A catalytic dewaxing process in which a hydrocarbon feed, usually a lubricant feed, is catalytically dewaxed in at least two catalytic dewaxing stages with an interstage separation of the light ends which are subjected to hydrogenation to saturate the olefins before the hydrotreated product is passed to the second dewaxing stage. The hydrotreated fraction may be the entire fraction below the lube boiling range with a lube feed or a lower boiling portion of it with separated higher boiling portions such as naphtha and distillate by-passing the second dewaxing step.Type: GrantFiled: March 9, 1987Date of Patent: January 19, 1988Assignee: Mobil Oil CorporationInventors: Kenneth R. Graziani, James R. Katzer, Chwan P. Kyan
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Patent number: 4695364Abstract: An improved multistage hydrodewaxing process for hydrodewaxing a hydrocarbon feedstock, such as a heavy or light distillate, is disclosed. A two-phase mixture of a hydrogen-rich gas stream and a liquid hydrocarbon is passed through a series of spaced catalyst beds in a single reactor, reaction vapors containing olefins, are withdrawn at each interspace between beds and replaced with hydrogen-rich saturated gas.Type: GrantFiled: January 3, 1986Date of Patent: September 22, 1987Assignee: Mobil Oil CorporationInventors: Kenneth R. Graziani, Chwan P. Kyan, Stuart S. Shih, Raymond M. Sowiak
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Patent number: 4648957Abstract: An improved method and apparatus are disclosed for hydrodewaxing hydrocarbon feedstock, such as heavy distillate or residual feed. The feedstock is hydrodewaxed in a first step. The resulting first effluent is separated to form a first vapor stream containing olefinic products and a first liquid stream, with a pour point of about 30.degree. to about 100.degree. F. The first liquid stream is then introduced into a second catalytic reaction, where the first liquid stream is hydrodewaxed to a specification pour point less than about 30.degree. F. The method and apparatus may also comprise routing primary products of hydrodewaxing, which contain olefins, as they are removed from the dewaxed first effluent, through an MOGDL unit to convert the olefins to additional high quality lubes. Improvements are due to removal of primary by-products containing olefins which inhibit dewaxing and accelerate catalyst aging and may cause reactor upsets. The addition of the MOGDL unit increases lube yields.Type: GrantFiled: December 24, 1984Date of Patent: March 10, 1987Assignee: Mobil Oil CorporationInventors: Kenneth R. Graziani, Chwan P. Kyan
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Patent number: 4342643Abstract: A shaped catalyst and methods of use are provided. The catalyst has substantially the shape of a cylinder having a plurality of longitudinal channels extending radially from the circumference of the cylinder and defining protrusions therebetween, said protrusions having a maximum width greater than the maximum width of the channels.Type: GrantFiled: June 5, 1981Date of Patent: August 3, 1982Assignee: Chevron Research CompanyInventor: Chwan P. Kyan
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Patent number: 4328130Abstract: A shaped catalyst and methods of use are provided. The catalyst has substantially the shape of a cylinder having a plurality of longitudinal channels extending radially from the circumference of the cylinder and defining protrusions therebetween, said protrusions having a maximum width greater than the maximum width of the channels.Type: GrantFiled: October 22, 1980Date of Patent: May 4, 1982Assignee: Chevron Research CompanyInventor: Chwan P. Kyan