Abstract: The invention relates to a process for the treatment of a hydrocarbon-containing feedstock making it possible to obtain a heavy hydrocarbon-containing fraction having a low sulphur content, said process comprising the following stages: a) a stage of hydrodemetallization in permutable reactors b) a stage of fixed-bed hydrotreatment of the effluent originating from stage a), c) a stage of hydrocracking in permutable reactors of the effluent originating from stage b), d) a stage of separation of the effluent originating from stage c), e) a stage of precipitation of the sediments, f) a stage of physical separation of said sediments from the heavy liquid fraction originating from stage d), g) a stage of recovery of the distillate cut used in stage e).

Abstract: Processes for the recovery of aromatic hydrocarbons from one or more vent gas streams associated with an aromatic complex. The vapor streams are passed to an absorption zone in which an aromatic-selective solvent absorbs the aromatics. The aromatic-selective solvent can be processed along with other solvent extraction streams within the aromatic complex. The absorption zone may be a portion of an existing vessel or column, such as an extractive distillation column or a stabilizer.

Abstract: The present disclosure relates to an apparatus for generating glycol and a method thereof. More particularly, the present disclosure relates to an apparatus for generating glycol including (a) an aldol reactor; (b) an extractor for extracting an aldol product, unsaturated aldehyde, using an organic solvent that is not mixed with water; (c) a distillation column for removing a raw material from a solution extract that is discharged from the extractor; (d) a hydrogenation reactor for hydrogenating a solution extract that is discharged from the distillation column; and (e) a divided-wall distillation column for isolating glycol from a hydrogenated solution product that is discharged from the hydrogenation reactor, wherein the hydrogenation reactor is a fixed-bed catalytic reactor that is filled with a copper-based catalyst, and a method of preparing the same.

Abstract: Methods and systems for separating hydrocarbons using one or more dividing wall columns are provided. The method can include introducing a hydrocarbon fluid to a first dividing wall column. A first overhead comprising methane, ethane, or a combination thereof, a first intermediate comprising ethane, a second intermediate comprising ethane, and a first bottoms comprising one or more hydrocarbons having three or more carbon atoms per molecule can be recovered from the first dividing wall column. The first overhead can be introduced to a process for producing a liquefied natural gas. The first bottoms can be introduced to a second dividing wall column. A second overhead comprising propane, a third intermediate comprising butane, and a second bottoms comprising one or more hydrocarbons having five or more carbon atoms per molecule can be recovered from the second dividing wall column. The second overhead can be introduced to the process for producing a liquefied natural gas.

Abstract: The invention provides a process and a system for processing hydrocarbon streams efficiently, especially natural gas streams that contain natural gas liquids including propanes, butanes, pentanes and higher hydrocarbons. A lean oil absorber is used to separate natural gas liquids, a side stripper with a side stripper reboiler is used to separate a propane/butane stream and a stabilizer reboiler is used to stabilize a natural gasoline product stream.

Abstract: The present invention relates to a feed distribution device in separation columns and a method of operation. In particular it relates to distillation columns in which the feed stream is substantially liquid phase, or a mixture of gas and liquid upstream of the column, but where the feed vaporizes or vaporizes more when it enters the column. More specifically, the feed distribution device contains a plurality of opening which allow the feed to vaporize inside the column and where the openings are maintained in critical condition during operation. Significant advantage is achieved through the implementation and use of the present feed distribution device.

Abstract: A feed distribution device in separation columns and a method of operation for such a device. In particular, distillation columns in which the feed stream is substantially liquid phase, or a mixture of gas and liquid upstream of the column, but where the feed vaporizes or partially vaporizes prior to or as it enters the column. More specifically, the feed distribution device contains a plurality of opening which allow the feed to vaporize prior to or as it enters the column and where the openings are maintained in critical condition during operation. Significant advantage is achieved through the implementation and use of the present feed distribution devices.

Abstract: Systems and processes for improving quality and yield of one or more distillate products generated in a distillation column are disclosed. The system comprises a feed inlet distributor that reduces the amount of liquid entrained in vapor rising from the feed zone of the distillation column, a wash zone collection apparatus having an improved design for collecting slop wax falling from a liquid/vapor contacting structure provided in the wash zone, a recirculation subsystem for recirculating at least a portion of the collected slop wax to the top of the wash zone for distribution as wash oil, and a control subsystem. The feed inlet distributor ensures a horizontal fluid flow path free of transverse surfaces thereby minimizing atomization of liquid droplets entrained in vapor in the feed stream.

Abstract: An improved apparatus strips HPNA's from hydroprocessed streams in a fractionation column having a split shell configuration. Only one vapor stripping feed is required to the split shell of the fractionation column. The resulting reduction in steam requirement provides a superior fractionation in the column.

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: A crude treatment system includes a primary and second distillation tower for treating crude containing corrosive material. The primary distillation tower fractionates first crude into a target fraction. The secondary distillation tower fractionates second crude having a corrosive material content greater than that of the first crude into a light fraction and a remaining heavy fraction. Corrosive material in the light fraction is insufficient to corrode the primary distillation tower. A light fraction supply line supplies the light fraction from the secondary distillation tower to the primary distillation tower for treatment. The secondary distillation tower and the supply line are made from a corrosion resistant material.

Abstract: The invention discloses a dual-flaw-baffle compound gasoline fractionator of ethylene unit, a quench oil circulation section is provided with micro baffles which are arranged in parallel in the vertical direction at intervals, a vertex angle of the micro baffle ranges from 90 to 139 degrees, symmetrical bevel edges at two sides of the vertex angle of the micro baffle are provided with symmetrical vertical hems, a medium oil circulation section is provided with dual-flow trays which are arranged in the vertical direction and have meshes with the diameter ranging from ?18 to 24 mm, a diesel oil separation section is provided with dual-flow trays which are arranged in the vertical direction and have meshes with the diameter ranging from ?13 to 24 mm, and a gasoline separation section is provided with dual-flow trays which are arranged in the vertical direction and have meshes with the diameter ranging from ?13 to 18 mm.

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: A process is provided 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, optionally further heating the mixture, flashing the mixture within a flash/separation vessel to form a vapor phase and a liquid phase, partially condensing the vapor phase by contacting with a condenser within the vessel, to condense at least some coke precursors within the vapor while providing condensates which add to the liquid phase, removing the vapor phase of reduced coke precursors content as overhead and the liquid phase as bottoms, heating the vapor phase, cracking the vapor phase in a radiant section of a pyrolysis furnace to produce an effluent comprising olefins, and quenching the effluent and recovering cracked product therefrom. An apparatus for carrying out the process is also provided.

Abstract: A process for steam cracking liquid hydrocarbon feedstocks containing synthetic crude oil comprises i) hydroprocessing a wide boiling range aliquot containing a) normally liquid hydrocarbon portion substantially free of resids and b) thermally cracked hydrocarbon liquid, boiling in a range from about 600° to about 1050° F., to provide a synthetic crude oil substantially free of resids; ii) adding to the synthetic crude oil a normally liquid hydrocarbon component boiling in a range from about 100° to about 1050° F.; and iii) cracking the mixture resulting from ii) in a cracker furnace comprising a radiant coil outlet to provide a cracked effluent, wherein the cracking is carried out under conditions sufficient to effect a radiant coil outlet temperature which is greater than the optimum radiant coil outlet temperature for cracking the synthetic crude oil separately. A method for upgrading synthetic crude for use in cracking is also provided, as well as a feedstock for cracking.

Abstract: A novel apparatus for producing sweet synthetic crude from a heavy hydrocarbon feed includes: an upgrader for receiving the heavy hydrocarbon feed and producing a distillate fraction including sour products, and high-carbon content by-products; a gasifier for receiving the high-carbon content by-products and producing synthetic fuel gas and sour by-products; a hydroprocessing unit for receiving the sour by-products and hydrogen gas, thereby producing gas and sweet crude; and a hydrogen recovery unit for receiving the synthetic fuel gas and producing further hydrogen gas and hydrogen-depleted synthetic fuel gas, the further hydrogen gas being supplied to the hydroprocessing unit.

Abstract: A novel apparatus for producing sweet synthetic crude from a heavy hydrocarbon feed comprising: an upgrader for receiving said heavy hydrocarbon feed and producing a distillate fraction including sour products, and high-carbon content by-products; a gasifier for receiving the high-carbon content by-products and producing synthetic fuel gas and sour by-products; a hydroprocessing unit for receiving the sour by-products and hydrogen gas, thereby producing gas and sweet crude; and a hydrogen recovery unit for receiving said synthetic fuel gas and producing further hydrogen gas and hydrogen-depleted synthetic fuel gas, said further hydrogen gas being supplied to said hydroprocessing unit.

Abstract: A novel apparatus for producing sweet synthetic crude from a heavy hydrocarbon feed comprising: an upgrader for receiving said heavy hydrocarbon feed and producing a distillate fraction including sour products, and high-carbon content by-products; a gasifier for receiving the high-carbon content by-products and producing synthetic fuel gas and sour by-products; a hydroprocessing unit for receiving the sour by-products and hydrogen gas, thereby producing gas and sweet crude; and a hydrogen recovery unit for receiving said synthetic fuel gas and producing further hydrogen gas and hydrogen-depleted synthetic fuel gas, said further hydrogen gas being supplied to said hydroprocessing unit.

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: Upgrading of a hydrocarbon feed containing sulfur, metals, and asphaltenes involves applying the feed to a distillation column for producing a substantially asphaltene-free, and metal-free fraction and a non-distilled fraction containing sulfur, asphaltenes, and metals. At least some of the substantially asphaltene-free, and metal-free distillate fraction is converted to a hydrogen donor diluent. The non-distilled fraction is processed in a solvent deasphalting unit for producing a deasphalted oil stream and an asphaltene stream. After a combined stream is formed from the hydrogen donor diluent and the deasphalted oil stream, the combined stream is thermally cracked forming a thermally cracked stream that is applied to the distillation column.

Abstract: A vacuum-creating apparatus of the unit is provided with a pump and a separator, wherein the pump is connected at its inlet to the separator, a jet device is made as a liquid-gas device and is connected at its outlet, by means of a pressure main, to the separator and at its liquid input to an output of the pump, wherein the longitudinal axis of the jet device is positioned vertically, the permissible deviation from the vertical axis being .+-.15.degree., an outlet cross section of a liquid supply nozzle of the jet device is positioned at a height of from 5 m to 35 m above an inlet to the separator and an outlet section of the pressure main is positioned below the level of the liquid in the separator to form a hydraulic seal.

Abstract: An installation for cleaning oil-polluted water, in particular at oil and gas production plants, is provided with a distillation column having a polluted water feed and at least one contact packing above which the outlet of the polluted water feed is located, a vapor discharge, a clean water outlet and a measuring device for the analysis of the water from the clean water outlet.

Abstract: The invention concerns a plant for purifying spent oil, including apparatus for dehydration, preferably by atmospheric distillation, directly followed by vacuum distillation producing a residue and at least one distilled oil fraction. The vacuum residue directly undergoes solvent extraction and the clarified oil obtained and the distilled oil fraction(s) undergo finishing hydrotreatment.

Abstract: A process and apparatus for the recovery of hydrocarbons from hydrocarbon containing composite materials, particularly roofing materials including asphalt and solid components to recover asphalt and the solid components. The process includes the steps of: agitating the materials with a solvent, preferably a terpene, to form a hydrocarbon/solvent mixture; heating the hydrocarbon/solvent mixture to vaporize the solvent; recovering the hydrocarbons; and recovering the solvent as a liquid by condensing the solvent vapor. The apparatus includes a composite materials washer for holding the composite materials and a solvent; means for agitating the composite materials washer to dissolve the hydrocarbons in the solvent; and a separator for vaporizing the solvent in the hydrocarbon/solvent mixture and recovering the hydrocarbons.

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 gas containing at least two constituents A and B having different temperatures is fractionated by carrying out at least the two cooling and contacting phases as follows:a) during a first stage, said gas is at least partly cooled to cause condensation of at least a first liquid fraction and said gas is brought into contact with said liquid fraction in at least a first zone of contact and heat exchange Z1, and at least a liquid fraction enriched in constituent A and at least a gaseous fraction are collected at the outlet of said first zone of contact and heat exchange Z1,b) during a second stage, said gaseous fraction from stage a) is at least partly cooled to cause condensation of at least a second liquid fraction and said gaseous fraction is brought into contact with said second liquid fraction in at least a second zone of contact and heat exchange Z2, and at least a liquid fraction enriched in constituent B and at least a gaseous fraction are collected at the outlet of said second zone.

Abstract: A liquid-vapor contact apparatus has pairs of vertical outer walls disposed in the manner of the vertical faces of a cuboid. The apparatus includes a plurality of spaced, parallel, vertical plates. Between each pair of adjacent plates there is a packing comprising a vertical array of corrugated liquid-vapor contact elements of the type that are used in structured packing. The corrugations in each element slope from top to bottom in a direction opposed to that in which the corrugations in contiguous elements slope. The two outermost plates form the walls of the apparatus. The walls comprise alternate edge portions of plates and of spacer bars. The plates define first and second sets of passages, respectively. One set of passages performs a first fractionation duty, and the other set another fractionation duty.

Abstract: A liquid-vapour contact apparatus has pairs of vertical outer walls disposed in the manner of the vertical faces of a cuboid. The apparatus includes a plurality of spaced, parallel, vertical plates. Between each pair of adjacent plates there is a packing comprising a vertical array of corrugated liquid-vapour contact elements of the type that are used in the assembly of structured packing, and having the apexes of the elements in fluid tight engagement with the respective plates. The corrugations in each element slope from top to bottom in a direction opposed to that in which the corrugations in contiguous elements slope. The two outermost walls form the walls of the apparatus. The other walls comprise alternate edge portions of plates and of spacer bars. Liquid is distributed appreciably evenly between the passages formed by adjacent vertical plates at the top of the apparatus and flows over the elements and effectively vertically downwards.

Abstract: A method and apparatus for stabilizing crude oil at the outlet of a well, including at least one separation step wherein the crude oil is pressure distilled in at least one distillation column into at least two cuts, i.e., a C.sub.1-5 hydrocarbon gas cut recovered at the top of the column and a stabilized crude oil cut recovered below the point where the original crude oil was injected into the column. The method advantageously includes at least one decompression step before the separation step.

Abstract: A downflow heat exchanger, particularly applicable as the main condenser/reboiler of a double column cryogenic air separation plant, wherein liquid distribution for uniform flow is carried out above the vapor passages and the well distributed liquid is passed into the liquid passages, preferably angularly onto the bridge fins, and then down through the liquid passages cocurrently with vapor in adjacent vapor passages.

Abstract: Waste lubricating oil, vegetable oil and animal fat are reprocessed into commercially usable diesel fuel and naphtha by thermocracking. A thermocracker unit is fired with sludge removed from the principal pool of oil or fat undergoing vaporization. The vapors are separated from liquids in a primary distillation tower with precisely controlled heating. Resultant vapors are partially condensed. Resultant liquids flow downward through a secondary distillation tower into a reboiler which is heated by a flue gas bypass with an auxiliary burner. Vapors leaving the secondary distillation tower are partially condensed and resultant fluids are passed to a light ends flash tank. Gases from the flash tank fuel the auxiliary burner. Liquids are collected and stored for selling as naphtha. Hot liquids are withdrawn from the reboiler and are immediately cooled to atmospheric conditions. Liquids within specification are stored in a diesel storage tank for further use and sale.

Abstract: Column having integrated heat exchangerA column is described including a column body (1) and at least one heat exchanger (2) installed directly on the column head. This heat exchanger is a plate heat exchanger which is specially arranged so that the condensing vapors and the condensate (12) generated on the exchanger surface move in one direction.A further embodiment of the invention relates to a column which contains a column body (1) and at least one plate heat exchanger installed between two trays and/or packing beds within the column, which plate heat exchanger is operated as a condenser and is situated within a collecting vessel (29) open at the top.A third embodiment of the invention relates to a column which includes a column body (1) and at least one plate heat exchanger (2), which is operated as an evaporator, and which is installed within the column between two trays and/or packing beds and/or in the bottom.The column according to the invention is distinguished by a space-saving construction.

Abstract: An apparatus and process for cryogenic separation of air are described which utilize a pipe distributor or a channel distributor for liquid distribution. The air separation apparatus contains a rectifying column having at least one section equipped with packing materials, wherein a liquid distributor is positioned thereabove. The main channel and/or the distributing channels of the liquid distributor are closed over at least a portion of their top. Also described is a liquid distributor for use in a mass transfer column.

Abstract: A downflow heat exchanger, particularly applicable as the main condenser/reboiler of a double column cryogenic air separation plant, wherein liquid distribution for uniform flow is carried out above the vapor passages and the well distributed liquid is passed into the liquid passages, preferably angularly onto the bridge fins, and then down through the liquid passages cocurrently with vapor in adjacent vapor passages.

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: Waste lubricating oil is reprocessed into commercially usable diesel fuel and naphtha by thermocracking. A thermocracker unit is fired with sludge removed from the principal pool of oil undergoing vaporization. The vapors are separated from liquids in a primary distillation tower with precisely controlled heating. Resultant vapors are partially condensed. Resultant liquids flow downward through a secondary distillation tower into a reboiler which is heated by a flue gas bypass with an auxiliary burner. Vapors leaving the secondary distillation tower are partially condensed and resultant fluids are passed to a light ends flash tank. Gases from the flash tank fuel the auxiliary burner. Liquids are collected and stored for selling as naphtha. Hot liquids are withdrawn from the reboiler and are immediately cooled to atmospheric conditions. Liquids within specification are stored in a diesel storage tank for further use and sale.

Abstract: A distillation system, particularly useful for the cryogenic distillation of feed air, employing a first column and a partitioned second column whereby three separate product streams may be withdrawn from the partitioned 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 distillation tower (1) has a plurality of liquid sidestream lines (5, 6, 7) and a multi-stage sidestream stripper (13) which includes a respective stripping section (14, 15, 16) for each sidestream line housed in a common, upright, cylindrical shell (28) which allows vapor to pass freely from each stage to the one above. Partial vaporization of each sidestream is achieved by applying a vacuum to the top of the stripper shell (point 21) and/or introducing strip gas at the bottom (point 20). Because the vapor passes serially through the stripping sections from the bottom of the stripper (13) to the top, the need to supply strip gas separately to the stripping sections and/or apply vacuum individually is avoided. The separation between the sidestream products is improved by including, in each stage, a rectification zone (22, 23, 24) positioned above the stripping section.

Abstract: A draw-off device is disclosed for a vacuum distillation column in which device a layer of gutters is provided. A secondary wall is arranged in the gutters creating a heat-insulating layer to reduce the condensation of vapor passing along the outer walls of the gutters.

Abstract: A liquid distribution device for more uniformly distributing a liquid to packed beds is composed of a box-pipe distributor, for the delivery of liquid to a pan distributor having a deck and risers postioned on the deck, with ells contained in the risers. The ells direct liquid axially through the risers so that gas/liquid interaction is minimized. The pan distributor also includes a plurality of holes positioned about the risers and a set of wall-ells about the periphery of the pan for more completely and uniformly distributing a liquid to packed beds positioned beneath the liquid distribution device.

Abstract: Tar sands are solvent extracted to form an oil-containing extract and a sandy residue. The solvent can be distilled from the oil and recycled. Residual solvent vapors can be adsorbed on an adsorbent bed. The sandy residue can be flash pyrolyzed to provide a combustible synthesis gas and/or combusted to provide process heat. Where the adsorber bed is formed from activated charcoal, a pair of beds on swing adsorption/regeneration cycles can be regenerated with steam and provide for continuous adsorption solvent vapors.

Abstract: A stripping column is comprised of one or more mixing channels situated in parallel arrangement, each channel in the form of a zigzag strip through which liquid cascades in a series of falls alternating with a corresponding series of pools. Simultaneously, vapor travels upwardly in a counter-current manner, intimately mixing with the liquid when forced through each successive pool. The column is especially useful in separating alcohol from fermented mash. The column is preferably employed with three other identical columns in a parallelogram structure to make a distillation unit of greater efficiency and capacity.

Abstract: A tarp assembly for covering an open top of a truck trailer has a tarp with a longitudinal edge fixed to one side of the trailer. A roll bar secured to the free edge of the tarp is rotated with a crank rod to roll the tarp to an open position and unroll the tarp to a closed position. A hold bar fixed to the free edge of the tarp with a plurality of straps is adapted to engage hooks secured to a side of the trailer to hold the tarp in a closed position. The hooks guide the straps and retain the hold bar in alignment for mutual engagement with the hooks.

Abstract: An apparatus and method are provided for the fractional distillation of liquids in a fractionation column wherein cool liquids from the bottom tray of the column are effectively prevented from passing out directly with bottoms product before first passing through a reboiler. The column is of the type which includes a hollow shell having a surge baffle plate which divides a bottom portion of the shell interior into a first region and a second region. A separation baffle plate is provided which extends into the first region. At least one seal pan whose bottom is closely adjacent to the upper edge of the separation baffle receives liquids flowing from the bottom tray by means of a downcomer.

Abstract: A hydrogen donor solvent selected from the group consisting of a full range crude oil and an atmospheric topped crude oil is used in a hydrovisbreaking process. The heavy fraction being processed is heated in the presence of hydrogen and the solvent under suitable hydrovisbreaking conditions. As a result, the amount of heavies in the feed to the hydrovisbreaking process is substantially reduced.

Abstract: In a continuous process for the extraction of crude refinery stock from oil-bearing sand, miscella produced earlier in the process is returned and mixed with oil-bearing sand to provide a feed slurry which, after heating, is separated into two streams, one of which is comprised predominantly of the coarser sand particles in the feed sand and miscella and the other of which contains most of the fine sand particles in the feed slurry. Miscella extracted by hot solvent from one of these streams is recycled to produce at least part of the miscella returned to produce the feed mix, and the other stream is processed to remove at least most of the sand and yield a miscella which is then distilled to separate the solvent for recycle to the extraction stages. Generally stated, a decantation step involving countercurrent extraction of the feed slurry will be used with sands which are comprised largely of fine particles.

Abstract: A novel process for the purification of used oil comprising removing the ash-forming components, then subjecting the oil to vacuum fractionation. A novel vacuum fractionation column is also disclosed.

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: Insertion of about one-half of a small diameter distillation column through the bottom of a larger diameter column permits the fractionation of a feed stream fed to the small column into three distinct high purity streams within one vessel. An annular space between the two columns functions as a stripping section which produces a pure stream of intermediate boiling range material. Open communication between the columns at the top of the small column eliminates the requirement of having a separate reflux system for the small column.