Abstract: A method of recycling gaseous hydrocarbons includes flowing a hydrocarbon gas composition from a secondary separator into a compressor unit to form a compressed mixture. The secondary separator includes a crude liquid hydrocarbon input stream from a primary separator. The method includes flowing the compressed mixture into a cooling unit to cool the compressed mixture, to form a cooled composition comprising liquid hydrocarbons. The method includes flowing the liquid hydrocarbons from the cooled composition into the primary separator.

Abstract: A distillation system and process for separating a multi-component feed mixture in a distillation system comprising a first distillation column having a first fired reboiler, and at least a second distillation column having a second heat-exchange reboiler, comprising the steps of a) introducing the feed mixture to the first column, and separating into at least a first top and a first bottom product; b) taking part of the first bottom product for providing heat to the second reboiler as a utility stream; and c) feeding part of said utility stream after heat-exchange as main feed to the second column for further separation. This process allows significant energy savings, by reduction of the amount of external heat required for the fired reboiler and omission of a conventionally used heat-exchanger.

Abstract: A process for re-refining used lubricating oil (ULO) having thermally unstable additives. ULO is heated by mixing with superheated lubricant boiling range hydrocarbons recovered and recycled from the process. The mixture of ULO feed and superheated hydrocarbons is charged to a vacuum column, producing an overhead vapor free of unstable additives and a residual fraction, containing additives. The overhead vapor is condensed to produce an overhead liquid of lubricant boiling range hydrocarbons, a portion of which is recovered as a product and a portion of which is recycled. The overhead liquid free of unstable additives, may be superheated without fouling to produce superheated fluid which can heat the ULO feed sufficiently to permit fractionation. Superheating may occur in a fired heater or preferably in a heat exchanger to prevent high temperatures and cracking of recycled liquid.

Abstract: An aromatics complex producing one or more xylene isomers offers a large number of opportunities to conserve energy by heat exchange within the complex. One previously unrecognized opportunity is through providing two parallel distillation columns operating at different pressures to separate C8 aromatics from C9+ aromatics. The parallel columns offer additional opportunities to conserve energy within the complex through heat exchange in associated xylene recovery facilities.

Abstract: An aromatics complex producing one or more xylene isomers offers a large number of opportunities to conserve energy by heat exchange within the complex. One previously unrecognized opportunity is through providing two parallel distillation columns operating at different pressures to separate C8 aromatics from C9+ aromatics. The parallel columns offer additional opportunities to conserve energy within the complex.

Abstract: An aromatics complex producing one or more xylene isomers offers a large number of opportunities to conserve energy by heat exchange within the complex. One previously unrecognized opportunity is through providing two parallel distillation columns operating at different pressures to separate C8 aromatics from C9+ aromatics. The parallel columns offer additional opportunities to conserve energy within the complex.

Abstract: A method is provided for producing vacuum in a vacuum oil-stock distillation column and includes pumping a gas-vapor medium out of a column by an ejector into a condenser; feeding a gas mixture and a high-pressure gas into a second gas-gas ejector from which the vapor-gas mixture is fed into a second condenser. A condensate is directed from the condensers into a separator in which the condensate is separated into a water-containing condensate and a hydrocarbon-containing condensate. The hydrocarbon-containing condensate is removed while the water-containing condensate is fed into a steam generator in which heat is supplied to the water-containing condensate from a hot distillate removed from the vacuum column and steam is produced from the water-containing condensate, the steam is fed as a high-pressure gas into the gas-gas ejectors. A plant for carrying out the method is also provided.

Abstract: An aromatics complex producing one or more xylene isomers offers a large number of opportunities to conserve energy by heat exchange within the complex. One previously unrecognized opportunity is through providing two parallel distillation columns operating at different pressures to separate C8 aromatics from C9+ aromatics. The parallel columns offer additional opportunities to conserve energy within the complex through heat exchange in associated xylene recovery facilities.

Abstract: The invention relates to the oil processing industry and can be used for producing vacuum in a vacuum petroleum distillation column. The inventive method involves pumping out a vapor-gas medium from the column by of a gas-gas ejector in such a way that a vapor-gas mixture is formed at the entry thereof and supplying said mixture to a condenser for producing a gas mixture and a vapor phase condensate. The gas mixture is supplied from the condenser to a liquid-gas jet apparatus and the condensate is delivered to an additional separator. A hydrocarbon-containing condensate is removed from the additional separator for the intended use thereof and a water-containing condensate is fed to a steam generator for producing steam by supplying heat of a hot distillate evacuated from the vacuum column. The thus obtained steam is used in the gas-gas ejector as a high-pressure gas.

Abstract: One exemplary embodiment can be a system for separating a plurality of naphtha components. The system can include a column, an overhead condenser, and a side condenser. Generally, the column includes a dividing imperforate wall with one surface facing a feed and another surface facing at least one side stream. Typically, the wall extends a significant portion of the column height to divide the portion into at least two substantially vertical, parallel contacting sections. Typically, the overhead condenser receives an overhead stream including a light naphtha from the column. Usually, a side condenser receives a process stream from the column and returns the stream to the column to facilitate separation. A cooling stream may pass through the overhead condenser and then the side condenser.

Abstract: A process for cracking hydrocarbon feedstock containing resid comprising: heating the feedstock, mixing the heated feedstock with a fluid and/or a primary dilution steam stream to form a mixture, flashing the mixture to form a vapor phase and a liquid phase which collect as bottoms and removing the liquid phase, separating and cracking the vapor phase, and cooling the product effluent, wherein the bottoms are maintained under conditions to effect at least partial visbreaking. The visbroken bottoms may be steam stripped to recover the visbroken molecules while avoiding entrainment of the bottoms liquid. An apparatus for carrying out the process is also provided.

Abstract: A process for decoking of a process that cracks hydrocarbon feedstock containing resid and coke precursors, wherein steam is added to the feedstock to form a mixture which is thereafter separated into a vapor phase and a liquid phase by flashing in a flash/separation vessel, separating and cracking the vapor phase, and recovering cracked product. Coking of internal surfaces in and proximally downstream of the vessel is controlled by interrupting the feed flow, purging the vessel with steam, introducing an air/steam mixture to at least partially combust the coke, and resuming the feed flow when sufficient coke has been removed. An apparatus for carrying out the process is also provided.

Abstract: Hydrocarbon feedstock containing resid is cracked by a process comprising: (a) heating the hydrocarbon feedstock; (b) mixing the heated hydrocarbon feedstock with steam and optionally water to form a mixture stream; (c) introducing the mixture stream to a flash/separation apparatus to form i) a vapor phase at its dew point which partially cracks and loses/or heat causing a temperature decrease and partial condensation of the vapor phase in the absence of added heat to provide coke precursors existing as uncoalesced condensate, and ii) a liquid phase; (d) removing the vapor phase as overhead and the liquid phase as bottoms from the flash/separation apparatus; (e) treating the overhead by contacting with a hydrocarbon-containing nucleating liquid substantially free of resid and comprising components boiling at a temperature of at least about 260° C. (500° F.

Abstract: A process for treating a crude containing natural gas comprising supplying the crude to a stabilization unit to obtain a gaseous stream and crude oil; supplying a compressed, gaseous stream at a low temperature to the bottom of a first column; partly condensing the first gaseous overhead stream, returning the liquid phase to the first column and supplying the methane-rich stream to a liquefaction plant; supplying an expanded bottom stream at a low temperature to the top of a second column; removing from the top of the second column a second gaseous overhead stream, and removing from the bottom of the second column a liquid bottom stream; vaporizing part of the bottom stream and introducing the vapor into the bottom of the second column; and introducing the remainder of the bottom stream into a crude oil stream at an appropriate point in or upstream of the stabilization unit, wherein the amount of heat removed from the first gaseous overhead stream is so adjusted that the concentration of C5+ in the first gase

Abstract: An energy efficient process scheme for a highly exothermic reaction-distillation system in which the reactor is external to the distillation column and the feed to the reactor is a mixture of at least one liquid product stream from the distillation column with or without other liquid/vapor reactants. The reactor is operated under adiabatic and boiling point conditions and at a pressure that results in vaporizing a portion of the liquid flow through the reactor due to the heat of reaction. Under these conditions, reaction temperature is controlled by reactor pressure. The pressure (and hence the temperature) is maintained at a sufficiently high level such that the reactor effluent can be efficiently used to provide reboil heat for the distillation column.

Abstract: A process for the recovery and purification of ethylene and optionally propylene from a stream containing lighter and heavier components that employs an ethylene distributor column and a partially thermally coupled distributed distillation system.

Abstract: An energy efficient process scheme for a highly exothermic reaction-distillation system in which the reactor is external to the distillation column and the feed to the reactor is a mixture of at least one liquid product stream from the distillation column with or without other liquid/vapor reactants. The reactor is operated under adiabatic and boiling point conditions and at a pressure that results in vaporizing a portion of the liquid flow through the reactor due to the heat of reaction. Under these conditions, reaction temperature is controlled by reactor pressure. The pressure (and hence the temperature) is maintained at a sufficiently high level such that the reactor effluent can be efficiently used to provide reboil heat for the distillation column.

Abstract: A process for ethane extraction from a gas stream based on turboexpansion and fractionation with no mechanical refrigeration is provided. The feed gas is sweetened and dehydrated by a conventional amine process and by a molecular sieve unit, to remove carbon dioxide and water. After this pretreatment, the feed gas undergoes to a series of cooling steps through a cryogenic brazed aluminum heat exchanger and fed to a demethanizer column. A stream rich in methane is recovered from the top of this column and fed to a centrifugal compressor and subsequently routed to a booster/turboexpander. The temperature of the methane gas is greatly reduced by the expansion allowing the cooled methane stream to be a cooling source for cryogenic heat exchanger. Feed for a de-ethanizer column comes from the bottom liquids of the de-methanizer column. Ethane is recovered overhead at the de-ethanizer column.

Abstract: Distillation is done by boiling, then cooling the vapor. If we decrease the pressure in the tube of distillation, We can have boiling at lower temperature and a rise of few degrees will boil the substance (crude oil, alcohol, salt water, etc . . . ) and turn it into vapor, then cooling by few degrees lead to the distilled substance (gas, alcohol, fresh water, etc . . .

Abstract: A processing method and system for separating methane-rich and ethane-rich components from an LNG stream. The LNG stream is preheated against a distillation column overhead vapor stream and against an overhead vapor product prior to entering the column. The overhead vapor product is methane-rich. The LNG stream may further be preheated against the column bottoms and another heating medium. The method may also include compressing the methane-rich product, condensing it against the LNG stream, and pumping it. The system may also comprise third and fourth heat exchangers configured to preheat the LNG stream with the bottoms product and the heating medium. Further, the system may provide for compressing the overhead vapor product prior to the its exchanging heat with the LNG stream and a pump for pumping condensed overhead vapor product. Additionally, the system generates all of the required reflux by cross exchanging the column overhead with the incoming LNG stream.

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: Process for separating a feedstock stream essentially consisting of hydrogen, methane and C.sub.3 /C.sub.4 -hydrocarbons, which first passes through a pretreatment, such as, e.g., dehydrogenation, after which the feedstock stream undergoes an at least one-stage partial condensation and separation into a C.sub.3 /C.sub.4 -hydrocarbon-rich fraction and into an H.sub.2 /CH.sub.4 fraction, after which a partial stream of the H.sub.2 /CH.sub.4 fraction is mixed in the not yet pretreated feedstock stream. The H.sub.2 /CH.sub.4 gas fraction drawn off from first separator (S1) is divided into two partial streams (10, 17), and first partial stream (10) together with liquid fraction (11) of first separator (S1) is fed to a second separator (S2) after partial condensation (W2), C.sub.3 /C.sub.4 -hydrocarbon-rich liquid fraction (16), drawn off at the bottom of second separator (S2), together with the second partial stream of H.sub.2 /CH.sub.

Abstract: A process for the dehydration and/or desalination and simultaneous fractionation of a petroleum deposit effluent containing oil, associated gas and water which can be saline, which process comprises:(a) at least one step for separating the liquid and gaseous phases at the pressure P1 for removal of the gas, producing a gaseous fraction G1, on the one hand, which is removed and a liquid fraction L1, on the other hand, which is sent to step(b) at least one step for separating, at least partly, the two liquid phases mixed in the liquid fraction L1, the aqueous phase being partly removed and the oil phase containing a quantity of residual aqueous phase being sent to step (c);(c) at least one distillation step carried out at a pressure P2 which is less than, or at the most equal to, the pressure P1 in step (a), in a distillation zone C1, said distillation being carried out in the presence of the oil phase coming from step (b), said zone C1 comprising an internal heat exchange zone and a boiling zone, and enabling

Abstract: A description is given of a process for the fractionation of oil and gas on a petroleum deposit effluent, including:(a) a stage wherein the liquid and gaseous phases are separated at the gas evacuation pressure P1, producing a gaseous fraction G1, on the one hand, which is evacuated, and a liquid fraction L1, on the other hand, which is constituted at least partially of oil, sending the liquid fraction L1 to stage (b);(b) at least one distillation stage carried out at a pressure P2 which is less than or at least equal to the pressure P1 in stage (a), in a distillation zone C1 which has an internal heat exchange zone and a reboiling zone, and which permits a gaseous fraction G2 to be recovered, on the one hand, and a liquid fraction L2 to be recovered, on the other hand, which is sent to the internal exchange zone, then evacuated; and(c) at least one recompression stage at the pressure P1 of at least a part of the gaseous fraction G2 which is at least partly mixed with the gaseous fraction G2 and evacuated.

Abstract: Processes are provided for the recovery of aromatic hydrocarbons from feeds comprising mixtures of aromatic and non-aromatic hydrocarbons using a mixed aromatic extraction solvent at extraction temperature of less than 250.degree. F. The mixed extraction solvent is comprised of a solvent component containing low molecular weight polyalkylene glycols and a cosolvent component containing glycol ethers. Extractive distillation and steam distillation operations are employed to separate the hydrocarbon components from the rich solvent extract. Low temperature extraction followed by subsequent heating of the rich solvent stream results in improved solvent selectivity, reduced solvent to feed ratios, improved thermal stability and energy savings.

Abstract: An apparatus and process for recovering a diesel-quality fuel from produced crude oil is described. The diesel-quality fuel is produced by flashing the crude feedstock at high temperatures and recovering the diesel quality fuel as a liquid from a refluxing exchanger. Process efficiency is enhanced by heat integration. The process is particularly applicable to remote locations, both onshore and offshore, where conventional fuel supplies are inadequate or not available.

Abstract: The invention involves visbreaking heavy oil under mild conditions in a vertical vessel containing a vertical elongate ring spaced inwardly from the vessel wall to form an outer open-ended annular chamber and an inner open-ended soak chamber. Heavy oil at 220.degree.-600.degree. F. is fed to top of annular chamber. A mixture of visbroken residuum and heavy oil at 730.degree.-800.degree. F. is fed to top of soak chamber. There is heat transfer through the ring from the soak liquid to the annulus liquid to assist in maintaining mild temperature in the soak chamber. The two streams mix in the base of the vessel whereby the visbreaking reaction is quenched. Part of the product is recycled and heated to provide the feed to the soak chamber.

Abstract: A heat integrated hydrotreating process has been invented. The feedstock is a cracked hydrocarbon stock which is mixed with hydrogen to suppress coking before heating in a multiple tube furnace to reactor inlet temperature. A minor portion of the feedstock is mixed with hydrogen and heated to reactor inlet temperature by quenching the hot reactor effluent. The minor portion is fed directly to the hydrogenation reactor, bypassing the furnace. By the process, high level heat is recovered.

Abstract: In the separation of a compressed multi-component hydrocarbon stream containing liquid and gas phases to produce a liquid product stream having a specified maximum vapor pressure and a gas product stream having a specified maximum cricondenbar, gas flaring can be reduced and other advantages obtained by the method of(i) separating the liquid and gas phases in one or more separation stages at progressively reduced pressures to produce said liquid product stream, and(ii) treating the recovered gas phase to obtain the gas product stream by partial condensation of the recovered gas phase and separation of the condensate so formed; wherein(iii) step (ii) includes the step of rectifying the recovered gas phase in a refluxing exchanger and separating the condensate so formed.

Abstract: The aim is to separate, by cooling and partial condensation of C.sub.2+, C.sub.3+ or C.sub.4 hydrocarbons contained in a gas mixture comprising, in addition to these components, even lighter constituents. For this purpose, the gas mixture is at first cooled until condensation of a smaller part of the hydrocarbons to be separated, after which the mixture is fed into the lower region of a fractionating column. A gaseous fraction is removed from the upper region of said column and is then again cooled and partly condensed in a heat exchanger, after which this partly condensed fraction is conveyed to the top of the fractionating column in the form of a return flow. In the case of C.sub.4 separation, the C.sub.4 hydrocarbons must represent more than 50% of the hydrocarbons contained in the gas.

Abstract: Processes are provided for the recovery of aromatic hydrocarbons from feeds comprising mixtures of aromatic and non-aromatic hydrocarbons using a mixed aromatic extraction solvent at extraction temperature of less than 250.degree. F. The mixed extraction solvent is comprised of a solvent component containing low molecular weight polyalkylene glycols and a cosolvent component containing glycol ethers. Extractive distillation and steam distillation operations are employed to separate the hydrocarbon components from the rich solvent extract.

Abstract: In a deasphalting process wherein the deasphalted oil is separated from the deasphalting solvent, the invention consists of performing said separation in at least two separate steps, differing by their temperatures, and of recovering heat from the deasphalted oil.The oil to be deasphalted (26) passes through an extractor (1), then through heat recuperators (3) and (4). The oil-solvent separation is achieved in two steps (5) and (11), under supercritical conditions, at different temperatures. The process has the particular advantage of saving power since external heat is provided (10) to only part of the charge.

Abstract: In a combination solvent extraction-steam distillation process for the recovery of aromatic hydrocarbons, the improvement comprising(a) introducing high pressure steam into a steam ejector;(b) passing the steam from step (a) to a first heat exchanger where it exchanges heat with cooler lean solvent coming from the bottom of the distillation column and is condensed;(c) returning the lean solvent from step (b) to the bottom of the distillation column;(d) passing part of the condensate from step (b) to a second heat exchanger where it exchanges heat with the warmer lean solvent coming from the bottom of the distillation column, cooling the lean solvent and vaporizing the condensate; and(e) passing the vapor from step (d) to the steam ejector in step (a).

Abstract: The process consists in successively separating increasingly heavy petroleum cuts at the head of a plurality of columns CO1, CO2, CO3 and Cl0 of a first series of columns which feed individually each column of the second series. The column CO7 is a gasoline stabilizing column which feeds an installation for fractionating light petroleum gases. The column CO4 is a gasoline fractionating column. The columns CO5 and CO6 are columns for separating petroleum naphthas from kerosine. The atmospheric residue collected at the bottom of the column Cl0 is processed in the vacuum distillation column Cl2 and the residue from this column is processed in the second vacuum distillation column Cl3 after reheating in a furnace.By carrying out a succession of progressive separations performed in a series of columns of small volume, more efficient utilization of the recovery heat is achieved.

Abstract: In a steam distillation process for the recovery of aromatic hydrocarbons wherein there is (i) a primary flash zone at the top of the distillation zone in which rich solvent is flashed and/or (ii) provision for the removal of side cut distillate vapors from about the middle of the distillation zone, the improvement comprising (a) heat exchanging flashed rich solvent vapors or side-cut distillate vapors with stripping water to provide stripping water vapors and stripping water at at least about the boiling point of water; (b) passing the stripping water vapors from step (a) to a steam ejector; (c) passing the stripping water from step (a) to a motive steam generator wherein the stripping water is vaporized under pressure; (d) passing the stripping water vapors from step (c) to the steam ejector referred to in step (b); and (e) passing the stripping water vapors, introduced into the steam ejector in accordance with steps (b) and (d), to the lower half of the distillation zone.

Abstract: An improvement in a process for the treatment of heavy oil in which a hydrocarbon diluent is subjected to distillation prior to its addition to a heavy oil production stream, to remove at least some of the light components in the diluent that would otherwise vaporize in the treatment process. A distillation unit for use in the process is also disclosed.

Abstract: The invention pertains to improvements in a fluid handling system in which a working fluid passes through a rotor while undergoing a pressure change. A shaft extends longitudinally from and rotates with the rotor. A first seal surrounds the shaft in axially spaced relation to the rotor, and a lubricant having a minimum boiling point is injected into the first seal adjacent the shaft at a pressure sufficient to cause the lubricant to flow axially toward the rotor. A housing surrounds the rotor and shaft and defines a contact zone between the rotor and the first seal for receiving both lubricant and a contact fluid such as the working fluid or a seal buffer gas used to isolate the working fluid from the lubricant. The contact fluid has a maximum boiling point substantially less than the minimum boiling point of the lubricant.

Abstract: In a method for separating a hydrocarbon mixture into relatively difficultly soluble hydrocarbons and relatively easily soluble hydrocarbons by extractive distillation using a polar solvent comprising feeding the starting hydrocarbon mixture to at least two evaporators, an extractive distillation column, a stripping column and a rectifying column; the improvement wherein(1) the polar solvent discharged at a high temperature from the bottom of the stripping column is recycled to the extractive distillation column after it has been cooled to a suitable temperature by giving up heat to a reboiler of the extractive distillation column, a reboiler of the rectifying column and successively to the two or more evaporators, and(2) the starting hydrocarbon mixture is divided into two or more streams and heated in two or more evaporators, one stream being evaporated in a first evaporator to a pressure necessary for introduction into the extractive distillation column and then fed to the extractive distillation column, a

Abstract: A process is disclosed for driving a turbine, which preferably is connected to an electrical generator, using energy supplied by the reboiler system of a fractionation column. The portion of the bottoms liquid of the column which is to be recycled through the reboiler is pressurized by a pump, and the high pressure liquid is heated and vaporized or brought to a supercritical state in the reboiler. The resultant high temperature stream is then depressurized through the turbine down to the desired pressure and temperature of the vapor stream used to reboil the column. The process is an extremely efficient method of generating electrical energy in a petroleum refinery or petrochemical installation.

Abstract: Process and apparatus for extracting an organic liquid from an organic liquid solute/solvent mixture. The mixture is contacted with a fluid extractant which is at a temperature and pressure to render the extractant a solvent for the solute but not for the solvent. The resulting fluid extract of the solute is then depressurized to give a still feed which is distilled to form still overhead vapors and liquid still bottoms. The enthalpy required to effect this distillation is provided by compressing the still overhead vapors to heat them and indirectly to heat the still feed. The process is particularly suitable for separating mixtures which form azeotropes, e.g., oxygenated hydrocarbon/water mixtures. The energy required in this process is much less than that required to separate such mixtures by conventional distillation techniques.

Abstract: Process and apparatus for extracting an organic liquid from an organic liquid solute/solvent mixture. The mixture is contacted with a fluid extractant which is at a temperature and pressure to render the extractant a solvent for the solute but not for the solvent. The resulting fluid extract of the solute is then depressurized to give a still feed which is distilled to form still overhead vapors and liquid still bottoms. The enthalpy required to effect this distillation is provided by compressing the still overhead vapors to heat them and indirectly to heat the still feed. The process is particularly suitable for separating mixtures which form azeotropes, e.g., oxygenated hydrocarbon/water mixtures. The energy required in this process is much less than that required to separate such mixtures by conventional distillation techniques.

Abstract: Bituminous sand such as oil sand or tar sand is mixed with a halogenated organic solvent which has a density greater than that of water at the same temperature. The slurry is continuously transferred to a conveyor system which is at least partially submerged in water, with the slurry being fed onto the portion of the conveyor which is submerged. As the sands move through the water on the conveyor, the organic solvent containing the bituminous material separates from the sand and forms a separate phase beneath the water. The sands ultimately move upwardly on the conveyor through the surface of the water. The organic phase is removed from beneath the water surface and the halogenated solvent is flashed therefrom in a flash evaporator chamber. Solvent vapors are withdrawn from the evaporator chamber by a compressor, and the compressed vapors are introduced into a condenser chamber.

Abstract: An entire crude oil stream is preheated by various sources of heat and brought to final temperature by a furnace. At this highest temperature, the stream is flashed into two portions, the heavier portion used only as a source of sensible heat for conservation. The vaporized fractions have their heat recycled into the crude oil stream and are then fractionated to extract a product of desired boiling range, flash point, and vapor pressure. The fractionation column is heated by the heavier, separated portion of the stream and refluxed by heat exchange with the crude oil stream.

Abstract: An improved process for the fractional distillation of a multi-component liquid in a multiple tray fractional distillation column having at least one sidedraw tray is disclosed, the process being characterized by elimination of draw tray overflow from at least one sidedraw tray, provision of a circulating reflux, and removal of reflux from the locus of the circulating reflux withdrawal zone.

Abstract: In a distillation process, the heats of distillates and bottom product are recovered to preheat the feed and to generate the steam of higher than 5 kg/cm.sup.2 G which in turn may be utilized to improve the distillation efficiency.

Abstract: A method and apparatus are disclosed relating to the recovery and reuse of heat during fractionation of liquids in a tray-type fractionating tower. According to this method, a portion of the feed to the tower is directed through heat exchange tubing positioned on the trays in such a way that the tubing is in contact with liquid there present so as to bring about an indirect exchange of heat between the said liquid on the trays and the liquid in the tubing, at the same time that there is occurring the normal transfer of heat by direct contact between the vapor and the liquid on the trays and the normal interchange of material components by direct contact between vapor and liquid on the trays, the said heat exchange tubing being serially connected so as to carry liquid from tray to tray.

Abstract: A process for distilling multicomponent hydrocarbon mixtures in which the relative volatility between the dominant component in the lightest product and the dominant component in the heaviest component is between 1.10 and 7. The hydrocarbon mixture is fed to groups of distillation columns each of which is provided with an overhead condenser and a bottom reboiler, the columns being arranged in succession to receive the product from the prior adjacent column. The operating pressure in the columns increases from the first column to the final column within prescribed limits and the products of the mixture are separately recovered at one time in the final column without being withdrawn from intermediate distillation columns. Heat is recovered from heat source streams of the process by heat exchange with heat sink streams by bringing the streams successively in contact with a plurality of groups of heat exchangers, each group being at a different temperature level.

Abstract: A method and apparatus for separating a predetermined fraction from a crude oil includes preheating the crude oil to vaporize a portion, and feeding the two-phase crude to a first stage flash evaporator. In the first stage evaporator, a vapor portion is separated from residual liquid and the residual liquid is used by means of heat exchange to preheat the crude oil. The vapor fraction from the first stage evaporator has an approximate 90% ASTM distillation temperature about 50-60.degree. F higher than the first stage evaporator temperature. The vapor fraction is condensed to form a condensate, and the condensate is conveyed to a stripping column for mass transfer with ascending vapors from a second stage boiling type evaporator. The second stage evaporator is operated at a vaporization temperature approximately equal to the 5% ASTM vaporization temperature of the predetermined petroleum fraction collected as liquid from the second stage evaporator.

Abstract: The amount of heat input required for the sequential fractionation of a crude oil in a crude column and a vacuum column is reduced by an improved heat exchange method wherein the desalted crude oil is flashed and the flash zone liquid is split into two streams. One of the streams is first heat exchanged against an atmospheric gas oil stream from the crude column and then against a first asphalt stream from the vacuum column. The other stream is first heat exchanged against a heavy vacuum gas oil stream from the vacuum column and then against a second asphalt stream from the vacuum column. The two streams are then recombined, heated and passed into the crude column.

Abstract: A process for the fractionation of hydrocarbons which includes the steps of extracting heat from a liquid sidecut stream, splitting the sidecut stream into two portions, splitting the liquid stream formed by condensing the overhead vapor stream into two portions, admixing one of the portions of the sidecut stream with one of the portions of the overhead liquid stream to form the reflux to the fractionation column, and admixing the other portion of each stream to form a product stream.