Abstract: A startup method for a fluidized catalytic cracking (FCC) unit operating with a magnetic catalyst separation means is disclosed. Magnetic strength, or separation severity, is maintained or increased until most of the catalyst has passed through the magnetic separation unit. After this point, magnetic flux and/or centrifugal forces, are decreased for lined-out operation. Preferably a MagnaCat.RTM. catalyst separation unit is used for magnetic fractionation of catalyst.

Abstract: Hydrocarbon feedstocks are hydroprocessed in parallel reactors, while hydrogen flows in series between the reactors. A first hydrocarbon feedstock and a hydrogen-rich recycle gas stream are introduced to a first reactor, where a first reactor effluent stream is produced and fed to a first separator, which separates the first reactor effluent stream into a first hydrogen-rich gas stream and a first hydroprocessed product stream. The first hydrogen-rich gas stream and a second hydrocarbon feedstock are fed to a second reactor, where a second reactor effluent stream is produced and fed to a second separator, which separates the second reactor effluent stream into a second hydrogen-rich gas stream and a second hydroprocessed product stream. A make-up hydrogen stream is added to the second hydrogen-rich gas to form the hydrogen-rich recycle gas stream that is compressed and fed to the first reactor.

Abstract: An improved method for cracking a hydrocarbon feedstock comprising passing the feedstock through furnace tubes at high temperatures. The improvement comprises tubes comprised of a nickel-cobalt alloy containing: nickel; 27.0-33.0 weight percent cobalt; 26.0-30.0 weight percent chromium; 2.4-3.0 weight percent silicon; 0.20-0.80 weight percent titanium; not more than 3.5 weight percent iron; not more than 1.5 weight percent manganese; not more than 1.0 weight percent columbium; not more than 1.0 weight percent molybdenum; not more than 1.0 weight percent tungsten; not more than 0.15 weight percent carbon; not more than 0.030 weight percent phosphorus; and not more than 0.015 weight percent sulfur. The improvement results in lower coking rates inside the furnace tubes, thus enhancing furnace efficiency and tube life.

Abstract: A twin-cell furnace for process stream preheat and utility steam superheat. The furnace uses a pair of vertical radiant cells with top supported, bottom guided, single row, multiple pass vertical coils fired on opposite sides by floor-mounted burners. An overhead convection section is centered between the radiant cells. Induced and forced draft fans are placed over the convection section to draw combustion gas into the stack and supply air through an air preheater, between the convection section and the stack, and to the floor burners and supplemental convection section burners. Additional convection coils are positioned in the hip section between the radiant cells and the convection section. The furnace design has reduced plot space requirements, increased flexibility in heating multiple services, and allows more even heating of the radiant tubes, and easier radiant tube replacement.

Abstract: The viscosity of quench oil circulated in a pyrolysis fractionation unit is controlled by contacting pyrolysis furnace effluent with a slip stream of 0.1-0.5 kg/kg of the quench oil, separating the resulting vapor-liquid mixture to remove tarry liquid, and feeding the remaining vapor to the fractionator. Removing the tarry liquid from the fractionator feed in this manner allows operation of the fractionator with less reflux, a higher bottoms temperature, and more heat recovery at a higher temperature.

Abstract: An apparatus and process for separating propane and benzene from alkylation reaction products in cumene production. An integrated fractionation tower combines the functions of propane separation, recycle benzene recovery as well as system dewatering to eliminate the need for separate depropanizer and dehydration columns and thus save capital and operating expenses.

Abstract: A residuum oil solvent extraction process is improved by using direct fired convection heaters for heating the asphaltene, the solvent-deasphalted oil phase, the deasphalted oil and the stripping steam, instead of hot oil heat exchangers. The convection heaters are fired using recirculated flue gas so that the hot flue gas supplied to the convection heaters has a temperature between 800.degree. F. and 1400.degree. F.

Abstract: An integrated distillation column having a partitioned stripping or absorption section is presented. The integrated stripping/distillation column comprises a single shell housing a refluxed absorption section and a reboiled stripping section. The stripping section is partitioned by a vertical wall into first and second separate portions having upper end in fluid communication the absorption section. The stripping portions include fluid isolated lower ends having separate reboilers. In the integrated absorption/distillation column, the absorption section is partitioned and separate reflux loops are provided for each portion of the absorption section. In such a manner, a two column distillation process can be combined into one for achieving space and equipment savings.

Abstract: An improved urea recovery process is presented. In the improved process, multiple vacuum rated surface condensers used to condense water vapor evolved during urea vacuum evaporation/concentration are replaced by a direct contact cooler/absorber to obtain substantial capital and utility cost savings. Improved heat exchange efficiency of the present process significantly reduces cooling water usage in comparison to the surface condensers.

Abstract: A process for liquefying natural gas containing mercaptans. Mercaptans are concentrated into a distillate stream by distilling the feed gas stream without specific pretreatment for mercaptans removal. Thus, the mercaptans removal equipment is much smaller since mercaptans treatment can take place at a point in the process where the flowrate is much lower. A portion of the treated distillate stream can be reinjected to the upstream distilling stage to facilitate mercaptan absorption.

Abstract: An impingement distributor for a shell and tube heat exchanger and a method of recovering waste heat from a hot gas which minimizes adverse heat flux at the outermost banks of tubes for enhanced operational reliability. The impingement distributor has a cylindrical distribution plate having evenly arranged rows of longitudinal perforations and a plurality of impact bars longitudinally aligned with the perforations. The hot fluid impinges on the impact bars, and direct impingement on the tubes is avoided.

Abstract: A spent catalyst distributor in a fluid catalytic cracking unit regenerator is self aerated by attaching to the underside of each trough arm a contiguous lip which captures rising aeration fluid and uses the aeration fluid to aerate spent catalyst flowing through the trough arms of the spent catalyst distributor. Orifices in the bottom plate of each trough arm pass the captured aeration fluid up into the spent catalyst flowing within the trough arm. The aeration fluid provides aeration and fluidization of the spent catalyst to facilitate the flow of the spent catalyst through the trough arms of the spent catalyst distributor.

Abstract: A method and apparatus for desulfurizing a gas and regenerating a sorbent is disclosed. The sulfur-containing feed gas which can be an effluent gas from a coal gasification reactor, for example, is desulfurized with a particulated metallic oxide sorbent in a transport riser. The sulfided sorbent is than separated from a desulfurized effluent gas and regenerated by contact with an oxygen-containing gas in a transport riser. The regenerated sorbent is separated from an SO.sub.2 containing offgas and recycled to the desulfurization step. The degree of sorbent conversion in the desulfurization step is held at a low level and the sorbent regeneration rate is increased to avoid excessive temperature rise in the regeneration step. In such manner, sorbent cooling can be substantially eliminated. The regeneration riser preferably comprises a once-through lift riser to minimize the riser transport gas requirements to just oxidant gas or oxidant gas mixed with a reduced amount of diluent gas.

Abstract: Disclosed are a process for converting low value hydrocarbon streams to hydrogen and/or synthesis gas products and a transport reactor useful in the conversion process. In the transport reactor, carbon produced is deposited on a circulating inert particulated carrier. The carbon deposited is partially oxidized to supply heat for the endothermic reactions. Reaction effluent gas leaving the transport reactor can be processed to remove particulate matter, sulfur compounds, and acid gases; condense the steam; and separate hydrogen from carbon monoxide to produce a purified hydrogen and/or syngas product. The present process has the flexibility to continuously handle all types of low value hydrocarbon feeds substantially without process disruption.

Abstract: An integrated ammonia/urea process and a plant for carrying out the same. The process comprises recycling a high pressure purge stream made up mostly of air from the urea synthesis cycle to the autothermal reformer in a syngas production unit of the ammonia process. In such a manner, compression energy required for ammonia synthesis can be reduced since a portion of the high pressure air feed to the autothermal reactor is supplied by the urea purge stream recycle. In addition, the equipment needed to clean up the urea purge stream is largely eliminated.

Abstract: A process for removing nitrogen from liquefied natural gas (LNG) using an enhanced surface, reflux heat exchanger is disclosed. A relatively warm high pressure LNG stream is directed countercurrently in heat exchange with a cool low pressure LNG stream to chill the high pressure stream and partially vaporize the low pressure LNG stream in the reflux heat exchanger. Vapor produced thereby strips the low pressure LNG stream of nitrogen. The cool low pressure LNG stream is produced by expansion of the chilled high pressure LNG stream. Vapor produced by the expansion is combined with the vapor produced in the exchanger and withdrawn overhead. Product LNG which is lean in nitrogen is withdrawn from the bottom of the exchanger.

Abstract: A vessel unheading device and method especially suited to handle shot coke produced in a delayed coker unit of a petroleum refining process. The device includes a car having mounted thereon one or more bottom head retracting support members which can be laterally positioned below the head assembly. The support member includes a vertically retractable member suitable for elevating a bearing plate mounted at an upper end thereof into pivotable load bearing engagement with the head, and a horizontally retractable member having one end attached to the bearing plate and another end attached to the vertically retractable member for applying a pivot force. Shot coke or other debris is captured from the opened vessel by a mobile chute wheeled into position adjacent the unheading car. Following complete retraction, the head is transported to a remote location for maintenance.

Abstract: A gravity sedimentation unit for thickening or clarifying a solids containing liquid is disclosed. The unit comprises a settling basin for receiving the feed and permitting the suspended solids to settle. A pump moves around the basin to discharge solids accumulating at the bottom. Support and vertical positioning of the pump is effected by a pump suspension which comprises a winch and a solids level detector. Horizontal positioning of the pump is effected by a bridge-type crane including a traverse with a drive for moving the traverse over the basin and a motorized trolley for moving the pump suspension back and forth along the traverse. Control of the pump travel is effected by a controller programmed to carry out regular search patterns through the basin.

Abstract: The present invention optimizes the relationship of variables associated with a process having inputs and outputs such that the process has controlled variables, manipulated variables, associated variables and disturbance variables, to maximize production rates.

Abstract: An integrated three-column process for recovering hydrocarbon distillate products from a hydroprocessing or hydrocracking reactor effluent stream and a hydrocarbon distillate product recovery train are disclosed. According to the present recovery process, an effluent stream from the cracking reactor is cooled and separated into light and heavy phase streams. The heavy phase stream is depressurized and stripped of light end components in a steam stripping column. The light phase stream is further cooled to separate a liquid stream which is combined with the light ends from the stripper and fed to a debutanizer. A C.sub.4 -rich light end stream taken overhead from the debutanizer is condensed to produce LPG product stream(s). A C.sub.4 -lean heavy end stream removed from the bottoms of the debutanizer is combined with a heavy end bottoms stream from the stripper and fed to a fractionator for fractionation into product distillate streams such as light and heavy naphtha, jet fuel, diesel oil, and the like.