Patents Assigned to Lummus Crest, Inc.
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Patent number: 5087783Abstract: An improved process for the alkylation of benzene in the presence of an alkylation catalyst. The catalyst bed may be caused to move in a direction countercurrent to the movement of the benzene and olefin, or a portion of the catalyst bed is periodically removed and replaced. A regeneration step, whereby the catalyst is heated in a controlled oxygen atmosphere in order to reactivate the catalyst, is also described.Type: GrantFiled: November 9, 1990Date of Patent: February 11, 1992Assignee: Lummus Crest, Inc.Inventors: Roger C. Johnson, Daniel McCarthy, Andrei Rhoe
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Patent number: 5082481Abstract: A process for recovering hydrogen from a cracking effluent wherein a cracking effluent is compressed, and then at least a portion of the hydrogen is separated from the cracking effluent prior to cooling of the cracking effluent to remove lower-boiling components. The separation of hydrogen is preferably accomplished by passing the cracking effluent through at least one semi-permeable membrane.Type: GrantFiled: April 10, 1990Date of Patent: January 21, 1992Assignee: Lummus Crest, Inc.Inventors: Richard K. Barchas, Thomas P. Hickey
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Patent number: 5003119Abstract: A process for the manufacture of alkylbenzenes wherein a feed of fresh and recycle benzene and fresh olefin are reacted in the presence of an alkylation catalyst in an alkylator having at least two reaction stages wherein each stage is adiabatic. Essentially all of the olefin is completely reacted in each stage of the alkylator. Fresh olefin is fed into each stage of the alkylator. Preferred alkylbenzenes which are produced by this process are ethylbenzene and cumene.Type: GrantFiled: February 12, 1990Date of Patent: March 26, 1991Assignee: Lummus Crest, Inc.Inventors: Helion H. Sardina, Roger C. Johnson, John E. Paustian, Renata M. Cox
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Patent number: 4983272Abstract: A process for producing coke from a combined feed. The combined feed is initially provided as a first portion which comprises easily cokable components and a second portion which is essentially free of easily cokable components. The first portion is heated to a temperature lower than that normally employed by a coking heater in a delayed coking process. The second portion is heated to a temperature at which a combination of the first and second portion provides combined feed at coking temperatures. The combined feed is then subjected to coking conditions.The first portion, in one embodiment, may be comprised of a fresh feed and the second portion may be comprised of a coker recycle. In another alternative, a fresh feed and a coker recycle are combined and fractionated to produce the first portion and the second portion. The first portion may include components which boil above a temperature of about 900.degree. F., and the second portion may be essentially free of easily cokable components.Type: GrantFiled: November 21, 1988Date of Patent: January 8, 1991Assignee: Lummus Crest, Inc.Inventor: Napoleon Stavropoulos
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Patent number: 4973780Abstract: An improved process for the alkylation of benzene in the presence of an alkylation catalyst. The catalyst bed may be caused to move in a direction countercurrent to the movement of the benzene and olefin, or a portion of the catalyst bed is periodically removed and replaced. A regeneration step, whereby the catalyst is heated in a controlled oxygen atmosphere in order to reactivate the catalyst, is also described.Type: GrantFiled: April 27, 1988Date of Patent: November 27, 1990Assignee: Lummus Crest, Inc.Inventors: Roger C. Johnson, Daniel McCarthy, Andrei Rhoe
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Patent number: 4940687Abstract: Dienes and/or acetylene impurities in an olefin feed; in particular a propylene feed, may be selectively hydrogenated in a single stage by use of a catalyst of palladium supported on alumina which is substantially crystalline alpha alumina, wherein the average pore radius is 200-2000 .ANG., with at least 80% of the pores having a pore radius within the range of 100 to 3000 .ANG.. The surface acidity of the catalyst is generally from 0.002 to 0.05 millimole of pyridine absorbed per gram of catalyst. The active palladium surface area is from 20 to 200 m.sup.2 /g. The palladium is in the form of crystallines having an average size of at least 25 .ANG..Type: GrantFiled: August 5, 1988Date of Patent: July 10, 1990Assignees: Beijing Research Institute of Chemical Industry, Lummus Crest, Inc.Inventors: Xin X. Liu, Bing Y. Zhao, Herbert Riegel, Jo-Lung Chien
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Patent number: 4875995Abstract: A system for adding and withdrawing solids to a high pressure reactor wherein there is provided improved control of flow and concentrations of a slurry of solids in a transport oil for introducing and withdrawing solids from the reactor. In addition, there is provided for improved heating and cooling of the solids.Type: GrantFiled: February 8, 1988Date of Patent: October 24, 1989Assignee: Lummus Crest, Inc.Inventors: Roger P. Van Driesen, William R. Adams, Mario Baldasarri, John Caspers, Harold Trimble
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Patent number: 4846958Abstract: The severity of a visbreaking operation is increased by treating product to remove a heavier phase in an amount of less than 15 weight percent and recycling treated product.Type: GrantFiled: May 26, 1988Date of Patent: July 11, 1989Assignee: Lummus Crest, Inc.Inventors: Robert J. Feldman, Andrei Rhoe, Roger P. Van Driesen, Joseph F. Puzio, Vincent A. Strangio
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Patent number: 4795551Abstract: In the solvent refining of a residual oil, a mixture of refined oil and refining solvent, and a mixture of pitch impurities and refining solvent are introduced into separate zones of a combination tower operated at a pressure of no greater than 100 psig to recover refining solvent from each of the mixtures. The combination tower is preferably A modified crude distillation tower from a preexisting crude unit, whereby idle crude units may be converted to solvent refining.Type: GrantFiled: July 15, 1985Date of Patent: January 3, 1989Assignee: Lummus Crest, Inc.Inventors: Gary L. Hamilton, Andrei Rhoe, Donald P. Satchell
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Patent number: 4773986Abstract: The severity of a visbreaking operation is increased by treating product to remove a heavier phase in an amount of less than 15 weight percent and provide a remaining product having a Shell Hot Filtration number of less than 0.25.Type: GrantFiled: December 18, 1986Date of Patent: September 27, 1988Assignee: Lummus Crest, Inc.Inventors: Robert J. Feldman, Andrei Rhoe, Roger P. Van Driesen, Joseph F. Puzio, Vincent A. Strangio
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Patent number: 4767521Abstract: Prior to upgrading a viscous feed by visbreaking, at least a portion of the feed is treated to remove a heavy phase in specified amounts, whereby the severity of the visbreaking may be increased. The Shell Hot Filtration number of the visbreaking product is reduced by at least 75%, compared to visbreaking of untreated feed at some severity.Type: GrantFiled: December 18, 1986Date of Patent: August 30, 1988Assignee: Lummus Crest, Inc.Inventors: Robert J. Feldman, James M. Chen, Andrei Rhoe, Roger P. Van Driesen, C. Bertil Fogman, Donald P. Satchell
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Patent number: 4765398Abstract: Two immiscible liquids are vaporized in heat exchanger tubes in a manner such that each tube receives both liquids and neither liquid is completely vaporized in the tubes.Type: GrantFiled: May 6, 1987Date of Patent: August 23, 1988Assignee: Lummus Crest, Inc.Inventor: Utah Tsao
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Patent number: 4750554Abstract: Internal tube sheet sealing apparatus assembly for tubular heat exchangers which operate with pressures of, e.g., greater than 1000 psi on both sides of the tube sheet and wherein the tube sheet itself is usually subject to a lower differential pressure, comprising tube sheet loading means including a plurality of shear means assemblies and bolts the can load the tube sheet joint independently of each other, said tube sheet loading means enabling (1) the tightness of the tube sheet joint and tube joints to be inspected during differential pressure hydrotesting of the shell side without the channel cover assembly mounted in place and (2) "in-service" re-loading of the tube sheet joint without removing the channel cover assembly.Type: GrantFiled: April 18, 1986Date of Patent: June 14, 1988Assignee: Lummus Crest, Inc.Inventors: Djin K. Oeij, Willem H. Brouwer, Adrianus C. J. Jansen
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Patent number: 4734266Abstract: A pump seal oil system for a reactor pump wherein seal oil is provided at a pre-determined rate of flow without changing the rate of flow in response to pressure differences between the seal oil in the pump and the reactor pressure. Seal oil is provided at a first rate when the reactor pump is in operation and at a second higher rate when the reactor pump is not in operation.Type: GrantFiled: December 20, 1985Date of Patent: March 29, 1988Assignee: Lummus Crest, Inc.Inventors: Roger P. Van Driesen, Bhaven Chakravarti
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Patent number: 4707245Abstract: Temperature is controlled in a hydrogenation reactor without changing the flow rate of feed into the reactor to maintain a pre-determined temperature in the reactor. In one embodiment, the firing rate of a fuel fired furnace for heating feed to the reactor is controlled in response to the temperature sensed in the reactor to maintain a pre-determined temperature. In another embodiment, the flow rate of a quenching stream for cooling feed to the reactor is controlled in response to temperature sensed in the reactor to maintain a pre-determined temperature in the reactor.Type: GrantFiled: December 20, 1985Date of Patent: November 17, 1987Assignee: Lummus Crest, Inc.Inventors: Mario Baldasarri, William R. Adams, John Caspers
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Patent number: 4698219Abstract: Spent flux containing calcium oxide and calcium sulfide, recovered from the reduction of iron ore, is carbonated, as an aqueous slurry, in two stages, with the first stage being operated at a pH to prevent reaction of calcium sulfide, and the second stage being operated at a pH at which calcium sulfide is reacted to produce an effluent gas containing hydrogen sulfide.Type: GrantFiled: October 11, 1983Date of Patent: October 6, 1987Assignee: Lummus Crest, Inc.Inventors: Utah Tsao, Joseph Kettell
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Patent number: 4654425Abstract: A mixed oxide catalyst precursor comprising vanadium and phosphorus treated in finely divided form with phosphoric acid and water soluble compound of aluminum and/or boron to improve resistance to attrition.Type: GrantFiled: December 10, 1984Date of Patent: March 31, 1987Assignee: Lummus Crest, Inc.Inventors: George D. Suciu, Giancarlo Stefani, Carlo Fumagalli
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Patent number: 4634796Abstract: Phenol feed to a steam distilling column, containing alpha-methylstyrene and mesityl oxide, is treated with a base, without acidification, and the heavy phenol product is acidified and distilled in a high purity column to recover high purity phenol as a sidestream and lighter components as overhead. Acidification after steam distilling, rather than prior to steam distilling, increases phenol recovery by reducing the overhead pasteurizing cut from the high purity column.Type: GrantFiled: March 25, 1985Date of Patent: January 6, 1987Assignee: Lummus Crest, Inc.Inventors: George D. Suciu, Ali M. Khonsari
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Patent number: 4628136Abstract: An improved process for the production of styrene through dehydrogenation of ethylbenzene in the presence of steam at elevated temperatures, comprising (1) recovering heat of condensation normally lost during separation of the various components of the dehydrogenation reaction effluent, especially of ethylbenzene from styrene, without need or use of a compressor and (2) using such heat to vaporize an aqueous feed mixture of ethylbenzene and dilution water that is introduced into the dehydrogenation reactor, preferably at about atmospheric pressure, thereby obviating the need to use steam to vaporize the liquid ethylbenzene feed and also enabling much of the diluent steam needed as sensible heat for the dehydrogenation reaction to be generated from water.Type: GrantFiled: December 17, 1985Date of Patent: December 9, 1986Assignee: Lummus Crest, Inc.Inventor: Helion H. Sardina
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Patent number: RE32265Abstract: .[.In a hydrogenation operation employing an ebullated catalytic bed, recycle is recovered from the hydrogenated product with at least 25%, by volume, of the recycle boiling above 950.degree. F. The recycle is cooled to a temperature of from 350.degree. to 600.degree. F. to separate coke precursors, prior to recycle to the hydrogenation. Higher conversion levels can be achieved by effecting recycle in such manner..]..Iadd.Disclosed is a hydrogenation process using at least one fluidized catalytic stage and a recycle material of heavy hydrogenated effluent. The heavy effluent material is cooled to a temperature within 350.degree.-600.degree. F. to separate toluene and heptane insoluble coke precursors prior to recycle. This separation may be enhanced by the use of centrifugation, filtration or a bed of particulate material (e.g. calcined coke). .Iaddend.Type: GrantFiled: May 17, 1985Date of Patent: October 14, 1986Assignee: Lummus Crest, Inc.Inventors: Harold Unger, Morgan C. Sze, Roger P. Van Dreisen