Abstract: The multistory crude oil refining apparatus includes: a crude oil receiving part; a first refining tank, wherein a first heater is mounted in the first refining tank; at least one first processed oil discharge pipe connected to one side of the first refining tank; a first processed oil discharge pipe pressure sensitive switch; at least one first impurity discharge pipe connected to the other side of the first refining tank; a first impurity discharge pipe pressure sensitive switch; a second refining tank, wherein a second heater is mounted in the second refining tank; at least one second processed oil discharge pipe connected to one side of the second refining tank; a second processed oil discharge pipe pressure sensitive switch; at least one second impurity discharge pipe connected to the other side of the second refining tank; and a second impurity discharge pipe pressure sensitive switch.

Abstract: A processing unit includes a naphtha hydrotreating unit comprising a first divided wall column, a naphtha splitter system, and a deisopentanizer column coupled to an output of a naphtha splitter of the naphtha splitter system, an isomerization unit coupled to an outlet of the deisopentanizer column, and a second divided wall column. The processing unit also includes an isomerization reactor coupled between the deisopentanizer column and the stabilizer column.

Abstract: The invention pertains to the field of petroleum processing and may find application in petroleum and petrochemical industries, in field of fuel power engineering. Method for processing of liquid hydrocarbon raw materials includes preliminary pre -treatment of raw materials flow and further processing with fractionation. The pretreatment is performed by means of forming of the primary flow with characteristics of a straight tubular laminar flow, whereupon the raw materials flow is forced into directed progressive rotary motion along vortex trajectory preserving laminarity, for this purpose it is directed to a spiral tubing while the primary flow the primary flow, is forced to move at a velocity the maximal value of which is on the boundary of vortex axile zone satisfies the conditions of achievement by the Reynolds number of critical values for tubular flow of liquid.

Abstract: A dual-mode dividing wall column capable of mode switching between a dividing wall column operating mode and a conventional column operating mode, and a distillation method using the dual-mode dividing wall column, wherein when compared to the existing conventional column, the invention can reduce device costs and energy and improve productivity is described. Furthermore, since a mutual conversion between a dividing wall column operating mode and a conventional column operating mode is enabled without shutting down a process, an economic loss which can occur during shutdown caused by the malfunction of a device can be prevented.

Abstract: Crude tall oil is subjected to a distillation process that substantially removes impurities. The process produces a combined pitch and a distillate of free fatty acids and rosin acids from two vacuum columns. The distillate stream is amenable to further downstream hydroprocessing.

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: 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 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: The invention may be used at installations with both an atmospheric column, and those with simultaneous application of an atmospheric column and a vacuum one and intended for fractional distillation of oil. The main distinctive feature of the method lies in the fact the hydrocarbon material is affected through primary and principal excitation by means of electromagnetic vibrations. The primary influence upon the hydrocarbon material is carried out prior to its feeding for thermal cracking, while the, principal influence is fulfilled in the rectifying column. For the method to be implemented, the primary excitation source in the installation is realized in a form of an electromagnetic oscillator, and the rectifying column is realized with possibility of resonance excitation provided, being the main exciter of the hydrocarbon material. The invention makes it possible to increase the percentage of output of lighter fractions, as well as to raise the quality of processing of raw materials.

Abstract: Method and apparatus producing a LNG stream, wherein before liquefaction heavier hydrocarbon components are removed from a NG stream to be liquefied, the method at least comprising the steps of: providing a vaporous feed stream (1) of natural gas; feeding the feed stream (1) into a distillation column (10); drawing a bottom stream (17) and an overhead stream (16) from the distillation column (10); and liquefying at least a part of the overhead stream (16) thereby obtaining a LNG stream; wherein the step of feeding the feed stream (1) into the distillation column (10) comprises the sub steps of: splitting the feed stream (1) into first (3a) and second (3b) substreams; feeding the first substream (3a) into the distillation column (10) via a first feed point (7a), at a pressure not lower than the feed stream pressure minus a pressure drop brought about by the said splitting of the feed stream (1); cooling the second substream (3b); and feeding the cooled second substream (7) into the distillation column (10) at

Abstract: A process is proposed for the separation of C5+ cuts by distillation into a low-boiler (A), a medium-boiler (B) and a high-boiler fraction (C) in one or more dividing-wall columns (TK), in which a dividing wall (T) is arranged in the longitudinal direction of the column with formation of an upper, common column region (1), a lower, common column region (6), a feed part (2, 4) with rectifying section (2) and stripping section (4), and a withdrawal part (3, 5) with rectifying section (5) and stripping section (3), with feed of the C5+ cut (A, B, C) into the central region of the feed part (2, 4), discharge of the high-boiler fraction (C) from the bottom of the column, discharge of the low-boiler fraction (A) via the top of the column, and discharge of the medium-boiler fraction (B) from the central region of the withdrawal part (3, 5), wherein the dividing ratio of the liquid reflux at the upper end of the dividing wall (T) is set in such a way that the proportion of high-boiling key components in the liquid re

Abstract: This invention is an improved distillation sequence for the separation and purification of ethylene from a cracked gas. A hydrocarbon feed enters a C2 distributor column. The top of the C2 distributor column is thermally coupled to an ethylene distributor column, and the bottoms liquid of a C2 distributor column feeds a deethanizer column. The C2 distributor column utilizes a conventional reboiler. The top of the ethylene distributor is thermally coupled with a demethanizer column, and the bottoms liquid of the ethylene distributor feeds a C2 splitter column. The ethylene distributor column utilizes a conventional reboiler. The deethanizer and C2 splitter columns are also thermally coupled and operated at a substantially lower pressure than the C2 distributor column, the ethylene distributor column, and the demethanizer column. Alternatively, a hydrocarbon feed enters a deethanizer 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: A process for recovering DCPD from a hydrocarbon feedstock comprising introducing the hydrocarbon feedstock to a first column, recovering an overhead stream from the first column comprising C9− hydrocarbons, recovering a bottom stream from the first column comprising C10+ hydrocarbons, feeding the bottom stream from the first column to a second column, recovering an overhead stream from the second column comprising DCPD, and recovering a bottom stream from the second column comprising fuel oil, wherein the two columns are sized and operated at defined conditions such as pressures, temperatures, reflux rates, and reboil rates.

Abstract: A process is proposed for the separation of C5+ cuts by distillation into a low-boiler (A), a medium-boiler (B) and a high-boiler fraction (C) in one or more dividing-wall columns (TK), in which a dividing wall (T) is arranged in the longitudinal direction of the column with formation of an upper, common column region (1), a lower, common column region (6), a feed part (2, 4) with rectifying section (2) and stripping section (4), and a withdrawal part (3, 5) with rectifying section (5) and stripping section (3), with feed of the C5+ cut (A, B, C) into the central region of the feed part (2, 4), discharge of the high-boiler fraction (C) from the bottom of the column, discharge of the low-boiler fraction (A) via the top of the column, and discharge of the medium-boiler fraction (B) from the central region of the withdrawal part (3, 5), wherein the dividing ratio of the liquid reflux at the upper end of the dividing wall (T) is set in such a way that the proportion of high-boiling key components in the

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 process and apparatus are disclosed that relate generally to a process for reducing harmful or unwanted emissions during the production of asphalt, such as blue smoke. The process includes the introduction of a pump around of the wax oil fraction for re-introduction into the vacuum tower. Additional desirable features include stripping trays below the wax oil collection tray and the feed zone. The result is to produce an asphalt product that creates less blue smoke in the hot mix plant. Another desirable feature is that a product can be created that meets Performance Grade specifications with the addition of polymers or other additives.

Abstract: A method and an apparatus for treating gasoline vapor by bringing gasoline vapor within a fuel tank into contact with a fluid gasoline and making the fluid gasoline absorb the gasoline vapor, in order to improve absorptivity of the gasoline vapor and to reduce the amount of the gasoline vapor introduced into a canister, thereby attaining a canister downsizing. The method and apparatus comprise a separation device of introducing the liquid gasoline within the fuel tank and separating it into a low boiling point component and a high boiling point component, and a gas-liquid contact device of bringing the gasoline vapor within the fuel tank into contact with an extractive gasoline composed of the high boiling point component separated by the separation device, whereby when contacting the gasoline vapor with the extractive gasoline, a part of the gasoline vapor is absorbed to the extractive gasoline, and a residual of the gasoline vapor not absorbed to the extractive gasoline is introduced into a canister.

Abstract: Process for the recovery of gaseous products from the product mixture obtained by contacting a hydrocarbon feed with a catalyst in a fluid catalytic cracking process, wherein the liquid, obtained by separating the top product of main fractionator into gaseous and liquid fraction, when supplied to the absorber has a temperature of between 8-25 DEG C. This liquid may be presaturated with gaseous top product from absorber; or also a high boiling fraction (cat craker naphtha/light cycle oil) may be first separated from this liquid by distillation.

Abstract: Fractional distillation performed to recover butane used as a desorbent component for adsorptive separation is integrated with the other fractionation of the raffinate stream of a C5-C6 paraffin adsorptive separation zone. A single fractionation column is employed to recover the desorbent butane, a highly branched paraffin product stream and a mono-branched paraffin rich recycle stream, thus reducing the cost of the process.

Abstract: Construction and operational costs of simulated moving bed adsorptive separation process units are reduced by recovering desorbent from both the extract and raffinate streams of the process in a single column. Both streams are fractionated to recover desorbent, which is removed at one end of a dividing wall column, while separate extract and raffinate products are removed from the other end of the column.

Abstract: A method of reducing the amount of energy required to fractionate a liquid hydrocarbon fraction is disclosed. Rather than use a single liquid feed point for a distillation column, the liquid feed is split into an upper feed portion and a lower feed portion. The lower feed portion is preheated to produce a vapor rich feed to a lower feed portion of the column, while charging, as a liquid, the remaining feed to an upper feed location at least one theoretical stage above the normal, single feed point location. Splitting the feed in this way reduces the total amount of heat required to reboil the column.

Abstract: An extractive distillation tower 4 supplied with a feedstock containing butadiene and a solvent and for distilling the feedstock to separate and purify the butadiene.

Abstract: Construction and operational costs of recovering the extract or raffinate product of a simulated moving bed adsorptive separation process units are reduced by employing a dividing wall column to perform the separation. The raffinate or extract stream is passed into the column at an intermediate point on the first side of the dividing wall, with the column delivering the adsorptive separation product as a sidedraw from the opposite side of the dividing wall. A stream of co-adsorbed impurity is removed as an overhead stream and desorbent is recovered as a net bottoms stream.

Abstract: A process and apparatus are disclosed that relate generally to a process for reducing harmful or unwanted emissions during the production of asphalt, such as blue smoke. The process includes the introduction of a pump around of the wax oil fraction for re-introduction into the vacuum tower. Additional desirable features include stripping trays below the wax oil collection tray and the feed zone. The result is to produce an asphalt product that creates less blue smoke in the hot mix plant. Another desirable feature is that a product can be created that meets Performance Grade specifications with the addition of polymers or other additives.

Abstract: A process and a device for separating ethane and ethylene from a hydrocarbon steam-cracking effluent is described. Effluent (1) is absorbed in an absorption column (7) by a cooled solvent (9). At the bottom of the column, liquid phase (12) that contains the solvent and the C2+ hydrocarbons is recovered and hydrogenated (15). The hydrogenation effluent that contains the solvent is introduced into a first distillation column (70) where the solvent is regenerated. The solvent is cooled and recycled at the top of absorption column (7). The C2+ hydrocarbons are collected at the top, and a condensed liquid phase is distilled in a second distillation column (77) to recover a C2 fraction that consists of ethane and ethylene.

Abstract: Construction and operational costs of simulated moving bed adsorptive separation process units are reduced by recovering desorbent from both the extract and raffinate streams of the process in a single column. Both streams are fractionated in the same column to recover desorbent, which is removed at the bottom of the column. The bottom of the column is divided into a reboiler sump section and a bottoms product-desorbent inventory section, with this reducing the equipment required in the overall process.

Abstract: A process for separating ethane and ethylene from a hydrocarbon steam-cracking effluent is described. Effluent (1) is absorbed in an absorption column by a cooled solvent (9). At the bottom of the column, the liquid phase that contains the solvent and the C2+ hydrocarbons is recovered and hydrogenated (15). The hydrogenation effluent that contains the solvent is introduced into a first distillation column (16). Ethane-ethylene mixture (17) is drawn off laterally from the column, and a phase (19) that contains the solvent and hydrocarbons with at least 3 carbon atoms is drawn off at the bottom of the column. This phase (19) is separated in a second distillation column (22), and C3+ hydrocarbons and, at the bottom of the column, regenerated solvent (26) that is cooled and that is recycled (9, 52) in the absorption column are collected.

Abstract: The present invention relates to fractionation improvements. Thus, in a fractionator having a fractionation vessel, a reactor effluent vapors inlet, a vapor feed contacting zone, a baffled contacting section above the vapor feed contacting zone, a tops section above the baffled contacting section, a heavy bottoms liquid hold-up pool section below the vapor feed contacting zone, a bottoms outlet, a bottoms recycle system with a heat exchanger with recycled, cooled bottoms fed back to the fractionation vessel at the heavy bottoms liquid hold-up pool section and above the vapor feed contacting zone, the improvements involve a separate remotely located bottoms liquid hold-up pool vessel for separating bottoms liquid holdup from vapor within the fractionation vessel to obtain a thermal separation and increased fractionation efficiency. The invention also relates to fractionation processes utilizing the aforesaid improvements.

Abstract: A method of distilling a crude oil and a contaminated liquid stream in an atmospheric distillation column (2) comprising the steps of (a) heating (13, 15) the crude oil at atmospheric pressure and introducing the heated crude oil into the inlet section (10) of the column (2); (b) removing from bottom a residue (19), removing from the top an overhead (20) and removing from the rectification section (7) at least one side stream (26, 28); (c) cooling (13) one of the side streams (28) and introducing the cooled side stream (29) into the rectification section (7) and partly condensing (21) the overhead (20) and introducing the condensed fraction (24) into the upper end of the distillation column (2); (d) supplying the contaminated liquid stream (40) to a membrane unit (3) provided with a suitable membrane (33), and removing a permeate (37) and a retentate (36); and (e) introducing the permeate (37) into the rectification section (7) and adding the retentate (36) to the crude oil (11) upstream of the furnace (1).

Abstract: A process for fractionating a heavy hydrocarbon stream to produce a lube oil fraction having a constant, predetermined flash point. A liquid stream is removed from the fractionator, cooled in response to a fractionator top temperature and returned to the fractionator above the original draw point.

Abstract: Incipient coke formation during hydrocarbon processing operations is detected by monitoring for C.sub.6- -fractions in heated hydrocarbon materials. The amount of C.sub.6- -fraction is an indication of the coke-forming tendency of the hydrocarbon materials.

Abstract: A process for selectively treating the components in a multi-component stream in a distillation column reactor. Additional catalytic distillation structures are placed as a secondary bed in the distillation column, either above or below the primary bed, and the selected component withdrawn after reaction in the primary bed to prevent its entry into the secondary bed.

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: In a process for the recovery of a polymerizable useful fraction, consisting of styrene, methylstyrenes, vinyltoluenes, indene, methylindenes and fractions whose boiling points are between styrene and methylindenes, from the crack gases of a steam cracker, the sidestream of the crack gas column is divided, by means of a distillation unit, into the useful fraction and into fractions which are recycled to the crack gas column.

Abstract: An improved fractionating process is provided wherein a liquid stream is withdrawn from the separation zone of the fractionator, is cooled and is recycled to the fractionator at a location below the location of withdrawal of the liquid stream. An improved fractionator is provided which comprises a withdrawal point from which a liquid stream is withdrawn, a cooler to cool the withdrawn stream and a means for recycling the withdrawn stream to a point below the withdrawal point.

Abstract: A method for rectification includes steps of supplying raw materials to a rectifying column from a raw material feed pipe; returning a refluent fluid from a refluxing pipe to the column; leading a hold-up liquid from a bottom tank having a higher surface to a bottom tank having a lower surface of a liquid in a bottom portion of the column; heating the hold-up in each of bottom tanks; exchanging heat by bringing a vapor produced by heating the bottoms into counter-current contact with the reluent liquid returned to the rectifying column on plates arranged in the rectifying column, taking out a vapor from the top of the rectifying column, and taking out bottoms from the bottom tank.

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: A process for the production of alkylaromatic hydrocarbons uses a working fluid to reduce the costs of separating an unreacted aromatic feed substrate from aromatic hydrocarbon products. Unreacted aromatic substrate is combined with a light hydrocarbon, such as propane, to form a combined effluent stream. The combined effluent stream enters a flash separator where unreacted aromatic substrate is lifted overhead with the light hydrocarbon while heavier aromatic products are recovered below. The aromatic substrate and light hydrocarbon are easily separated in a simple separation zone. Lifting the aromatic substrate with the working fluid reduces the volume of aromatic substrate that remains with the aromatic product so that the more energy intensive separation of the aromatic substrate and aromatic product is performed on a reduced volume of material.

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 fractional distillation tower which is divided into a plurality of sections by total drawoff trays, and wherein at least one fraction is withdrawn from each section. The cut point temperature between fractions is determined based on the partial pressure and temperature of the vapor in the upper portion of a section. The thus determined cut point temperature may be compared to a set point with the results of the comparison being utilized to maintain the actual cut point temperature between fractions substantially equal to the desired cut point temperature.

Abstract: A process for the production of alkylaromatic hydrocarbons uses a light hydrocarbon recycle to reduce the costs of separating an unreacted aromatic feed substrate from aromatic hydrocarbon products. Unreacted aromatic substrate is combined with a light hydrocarbon, such as propane, to form a combined effluent stream. The combined effluent stream enters a flash separator where unreacted aromatic substrate is lifted overhead with the light hydrocarbon while heavier aromatic products are recovered below. The aromatic substrate and light hydrocarbon are easily separated in a simple separation zone. Lifting the aromatic substrate with the light hydrocarbon reduces the volume of aromatic substrate that remains with the aromatic product so that the more energy intensive separation of the aromatic substrate and aromatic product is performed on a reduced volume of material.

Abstract: The temperature of a crude oil provided from a crude oil preheat furnace to a crude tower is substantially minimized by controlling such temperature so as to maintain a desired minimum overflash flow in the crude tower. Also, the temperature of each of the individual coils in the preheat furnace are balanced with respect to each other. Such minimization and balancing results in substantially optimal utilization of the fuel provided to the preheat furnace which results in considerable economic savings with respect to the operation of the preheat furnace.

Abstract: The Reid Vapor Pressure of a hydrocarbon mixture consisting essentially of hydrocarbons selected from the same series is determined based on the actual temperature and vapor pressure of the hydrocarbon mixture. The thus determined Reid Vapor Pressure may be compared to a set point for the Reid Vapor Pressure with the results of the comparison being utilized to maintain the actual Reid Vapor Pressure substantially equal to the desired Reid Vapor Pressure.

Abstract: The heat to a feed in a distillation operation is controlled in response to the amount of liquid in a liquid condensate collection means.

Abstract: A vapor-liquid contacting process is disclosed which may be used in gas treating, absorption or in fractional distillation. The process is characterized by the utilization of a liquid support plate (tray) having a flat vapor-liquid contacting area formed by uniformly spaced parallel members which provide long narrow passages for the rising vapor. The process is especially useful when a low pressure drop through the liquid support plate or a high tendency of the liquid support plate to prevent weeping is desired. The process allows higher operating capacity than the use of valve-type liquid support valves.