Abstract: A process for use of magnetic separation to remove non-magnetic particles from FCC catalyst is disclosed. A stream of circulating catalyst from a fluidized catalytic cracking (FCC) unit is charged to a magnetic separator. The catalyst is magnetically fractionated into at least three fractions, a high-metals fraction which is discarded, an intermediate-metals content fraction which is directly recycled to the FCC unit, and an inert, relatively magnetic metals-free fraction which is also discarded. Preferably, the high-metals fraction is immediately mixed with the inert, low-metals fraction, and the combined high-metals/inert fraction is pneumatically transmitted together to a spent catalyst storage facility for disposal.

Abstract: Methanol emissions in the CO.sub.2 vent from a synthesis gas unit in an ammonia or hydrogen plant are reduced by contacting raw synthesis gas from a low temperature shift converter with recycled stripped condensate to absorb methanol. The synthesis gas is treated in a purification unit to form the CO.sub.2 vent of reduced methanol content. The condensate from the contacting step is steam stripped to form a process steam stream suitable for feed to the reformer and a stripped process condensate stream suitable for offsites polishing, a portion of which is recycled for contacting the raw synthesis gas.

Abstract: A plant and process for converting associated gas from crude oil to methanol at or near the wellhead. The process uses partial oxidation of the associated gas, direct quench, liquid phase methanol conversion wherein substoichiometric H.sub.2 :CO is converted to methanol, and a loop purge to a gas turbo generator to provide all of the plant power requirements. This results in avoiding a complex vapor phase, multiple reactor methanol loop and steam-catalytic reforming, and obtains a compact, low-cost, self-sufficient facility suitable for remote locations.

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: A process and apparatus for incorporating additives into a circulating inventory of equilibrium catalyst in a fluid catalyst cracking (FCC) unit are disclosed. Hot regenerated catalyst is removed from the FCC regenerator, cooled, optionally subjected to magnetic catalyst separation, and at least a portion of the cooled catalyst is contacted with a solution of an additive material without forming a separated liquid phase. Additive treated catalyst is recycled to the FCC unit, preferably directly into the regenerator.

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: A process for metals passivation of metals-contaminated equilibrium catalyst (ECat) used in a fluidized catalytic cracking (FCC) process is disclosed. Repeated treatment of a slip stream of ECat in a high-strength magnetic field, preferably a magnetic catalyst separator, changes the properties of the ECat, promoting growth of relatively large crystals or deposits of metal deposits on ECat which are less catalytically poisonous. Magnetic conditioning permits an increase in metals levels on ECat from, e.g., 3000 to 4000 ppm, without increasing hydrogen and/or coke make. Metals passivation by magnetic conditioning can also be used to concentrate feed metals on the oldest catalyst in the unit. This allows magnetic separation of the oldest catalyst in the unit after 1-6 months of magnetic conditioning, even though feed metals levels are otherwise insufficient to permit effective magnetic catalyst separation.

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: A regenerator in a FCC unit, with the reactor elevated above the regenerator and a side entry spent catalyst introduction to the regenerator, is modified by installing a spent catalyst distribution apparatus along a central vertical axis of the regenerator to radially discharge the spent catalyst and 10-50 percent of the regeneration air into the dense phase of the catalyst. The existing compressor may be used to supply the regeneration air to the spent catalyst distributor. The remaining 50-90 percent of the regeneration air is supplied to the air distribution grid. The retrofit improves spent catalyst distribution and mixing in the regenerator to avoid dilute phase CO combustion or afterburning in the offgas.

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 retrofit method for increasing production capacity of an ammonia plant having a front end including in series primary and secondary reformers and a shift converter for reacting a hydrocarbon feed, steam and air to form a make-up syngas stream comprising hydrogen and nitrogen at about design stoichiometry, and a synthesis loop wherein a recycle syngas stream is combined with the make-up gas to form a syngas feed to ammonia converters. The retrofit involves the installation of an air separation unit to supply oxygen and nitrogen streams. The oxygen is used to enrich air supplied to the secondary reformer and increase the hydrogen content of the make-up gas substantially above the design stoichiometry and capacity. The nitrogen stream is supplied to the synthesis loop to obtain a desired hydrogen to nitrogen ratio in the syngas feed to the ammonia converters and compensate for the excess hydrogen in the make-up gas.

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: A thermal transition section for introducing a high temperature cracked process gas into a quench exchanger having an inlet end comprising inner and outer concentric pipes connected to a closure ring to define an annulus between the pipes and an interior exchanger surface having an inside diameter. The transition section has a metal outer wall extending from a downstream end connected to the closure ring to an upstream end connected to a metal transition cone. The transition cone is connected at an upstream end to a line for supplying the process gas. The downstream end of the inner sleeve has an outside diameter matching the inside diameter of the interior exchanger surface. A precast, pre-fired single-piece ceramic insert substantially fills the annulus between the outer wall and inner sleeve. By using the ceramic insert, particularly a relatively long insert, thermal stresses are reduced and coke formation in the annulus is inhibited.

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.