Abstract: A process for rectificatively separating at least one (meth)acrylic monomer-containing fluid by feeding the fluid into a rectification column containing at least one sieve tray without a runoff segment, wherein an elementary cell is obtained from a number of centers of passages in a sieve tray, and the cell shifts regularly and repeatedly along its edges, the lengths of two shifting vectors being the lengths of the edges of the cell along which the shifting is effected; an arrangement of the centers is such that the positions of an ideal center and a real center are separated by ?1% of half of the sum of the lengths of the two shifting vectors; and an arrangement of the passages is such that the sum of non-overlapping surface areas of an ideal passage with a real passage and vice versa is ?1% of the surface area of the ideal passage.

Abstract: A krypton-xenon concentrate is first divided into krypton and xenon fractions in a preliminary rectifying column. Semi-volatile impurities are removed from each fraction, and production krypton and xenon are obtained from the refined fractions in krypton and xenon production columns. A recovered krypton flow is produced in a krypton recovery rectifying column. Reflux is formed in condensers-evaporators of rectification columns of the device in such a way that the formation of a solid phase is excluded. The operation of the rectification columns is initiated by supplying krypton to a contacting space.

Abstract: A process is provided herein for the high yield production of high purity glacial methacrylic acid (“HPMAA”) that is substantially pure, specifically 99% pure or greater with a water content of 0.05% or less.

Abstract: In an atmospheric fractionator, the number of theoretical stages are increased in the upper light distillate flash zone and in the middle heavy distillate flash zone. The middle distillate pumparound circuit has been eliminated. The reflux to distillate ratio for the light distillate as well as the effluent feed temperature have been substantially increased. As a result, increased yields for middle distillate (e.g. kerosene) and heavy distillate (eg diesel) have been achieved which more than offset the increased energy consumption used for the higher feed temperature In the example of hydrocracking technology, the improved fractionation has benefits in the hydrocracking unit outside of the fractionation unit Increased fractionation efficiency reduces the severity in the hydrocracking unit reactor catalyst and less hydrogen is consumed. The invention can be applied to several other refining technologies besides hydrocracking.

Abstract: An improved process for separation of liquid mixtures involves vapor stripping followed by mechanical compression of the vapor which is then exposed to a permeation membrane for separation of the compressed vapor.

Abstract: An apparatus for producing a xylene isomer, which integrates the removal of olefins into a reaction zone of the apparatus is disclosed. Apparatus of this invention enable the use of aromatic feedstocks containing olefins and reduce or eliminate the need for feed pretreatment by olefin removal assemblies or zones such as hydrotreating, hydrogenation, and clay and/or molecular sieve treating, thereby reducing capital and operating costs.

Abstract: A vapor/liquid separation apparatus for treating a flow of vapor/liquid mixtures of hydrocarbons and steam comprises a vertical drum with a side inlet to introduce hydrocarbon/steam mixtures, an overhead vapor outlet, and a lower section in communication with a cylindrical boot of less diameter than the drum, the boot comprising sufficient gas-liquid contact surface, e.g., that provided by one or more sheds, baffles and/or distillation trays, to provide at least a partial theoretical distillation stage, and a lower portion for receiving liquid from the drum, a lower outlet for removing the liquid, and an inlet for introducing a stripping gas, such as steam, hydrogen, light crackable hydrocarbon, and/or methane, below the distillation tray and preferably above the level of liquid in the boot.

Abstract: A column is described for carrying out reactive distillations in the presence of a heterogeneous particulate catalyst having an ordered packing or random packings which form intermediate spaces in the column interior, the quotient of the hydraulic diameter for the gas flow through the ordered packing or the random packings and the equivalent diameter of the catalyst particles being in the range from 2 to 20, preferably in the range from 5 to 10, in such a manner that the catalyst particles are introduced into the intermediate spaces, distributed and discharged loose under the action of gravity.

Abstract: A decomposition reaction apparatus or distillation apparatus for acrylic acid in which a column bottom liquid heated in a reboiler (5) is supplied from a supply port (1a) provided on a side wall of a column body (1) having: a top plate (12a) above the supply port (1a); and an impingement plate (12b) provided vertically to the top plate (12a), for preventing scattering of the column bottom liquid to a supply direction. The top plate (12a) is provided such that the top face of the top plate (12a) is inclined downward from a base end to a tip end. The present invention allows: suppression of formation of a polymerized product due to flowing of a liquid or gas heated in a reboiler into a column with a simple structure; and a stable continuous operation of column equipment over a long period of time.

Abstract: A system and process that are a hybrid of distillation and membrane separations offers a highly efficient means of separating a fluid feed mixture into organic, solid, and aqueous components. The distillation section is followed by two membrane separation sections operated in parallel, with the distillation section separating the feed mixture into an organics-rich fraction and an organics-depleted and solids-rich fraction. One membrane section operates on the organics-rich fraction and separates it into a more organics-rich sub-fraction and a water-rich, organics-depleted sub-fraction, while the other membrane section operates on the organics-depleted, solids-rich fraction from the distillation section and separates it into a solids-rich sub-fraction and a solids-depleted, water-rich sub-fraction.

Abstract: A process for light water detritiation which includes the steps of water distillation for tritium stripping and enriching, followed by chemical conversion of tritium enriched water to elemental hydrogen, and finally by one or more thermal diffusion columns for final tritium enrichment. The combination of process steps takes advantage of water distillation large throughput capability at low tritium concentration with the simplicity of thermal diffusion for small throughput final tritium enrichment. The water distillation front-end and the thermal diffusion back end processes are compatible with any intermediate chemical conversion process such as electrolysis or water gas shift reaction to convert tritiated water to elemental hydrogen.

Abstract: A collector-distributor combination in a column, which is filled with a random packed bed or with a structured packing, is disclosed. The liquid phase is guided over a collector with inclined planes to a central opening, which is connected to an ascending pipe, from which the liquid phase is distributed to the plane underneath via the distributor pipes. By guaranteeing a constant filling level of the liquid phase in the ascending pipe, the distributor functions as a pressure distributor. The liquid phase is distributed independent of the inclination of the column over the entire length of the distributor pipes. The gaseous phase passes through the collector via the chimney.

Abstract: A method, system, and apparatuses for simultaneous heat and mass transfer utilizing a carrier-gas at various absolute pressures are described. A method may include: thermally coupling at least two continuous contacting apparatuses together; varying the pressure between the at least two continuous contacting apparatuses; allowing heat removed from the first continuous contacting apparatus to be the heat delivered to the second continuous contacting apparatus. A system may include: at least two continuous contacting apparatuses thermally coupled together and operating at different absolute pressures. A continuous contacting apparatus may include: an evaporation chamber and a dew-formation chamber both operating at an absolute pressure in a vacuum range. A continuous contacting vapor recompression apparatus may include: an evaporation chamber operating at a first absolute pressure; and a dew-formation chamber operating at a second absolute pressure higher than the first absolute pressure.

Abstract: It is an object of the present invention to provide a specific process that enables an aromatic carbonate to be produced with high selectivity and high productivity stably for a prolonged period of time on an industrial scale of no less than 1 ton per hour using a continuous multi-stage distillation column from a dialkyl carbonate and an aromatic monohydroxy compound containing specified amounts of an alcohol and an aromatic carbonate. Although there have been many proposals regarding the process of producing the aromatic carbonate using a reactive distillation method, these have all been on a small scale and a short operating time laboratory level. There have also been no disclosures whatsoever of a starting material containing necessary amounts of the alcohol and the aromatic carbonate for use in an industrial production, which have been considered to be disadvantageous in terms of the equilibrium, let alone the process and apparatus for the industrial production.

Abstract: A divided wall exchange column includes a dividing wall strengthened by stiffening members and/or a double wall design to better withstand pressure differentials and minimize temperature differentials. When a double wall is used, cost of manufacture and installation is minimized by reducing the manufacturing tolerances required while providing a design robust in construction, installation, and operation. When structured packing is used, the stiffening members, combined with positioning the layers of packing at preferred angles relative to the dividing wall, result in minimal interference with the heat and/or mass transfer process while minimizing the complexity of manufacture and construction of the packing. Further, by positioning the top layer of structured packing at other preferred angles relative to the dividing wall, a simplified liquid distributor design may be used in the divided wall exchange column while the layers below may still be orientated as described above with all the associated benefits.

Abstract: A process for reacting a first component with itself or a second component to produce a third component in which a first material comprising a first component or said first component and a second component is fed to divided wall column having a catalytic distillation structure in at least one of the separate vertical sections of the divided wall column where concurrently: (1) a first component alone or with a second component is contacted with a catalytic distillation structure in a distillation reaction zone thereby catalytically reacting at least a portion of the first component with itself or with the second component to form a product and (2) a first mixture comprising the first component and the product or the first component, the second component and the product; and withdrawing the product from the distillation column reactor; while within the column concurrently with the catalytic reaction and fractionation a second mixture is fractionated, which contains the first component and the product or first a

Abstract: A process comprising receiving a hydrocarbon feed stream comprising carbon dioxide, separating the hydrocarbon feed stream into a light hydrocarbon stream and a heavy hydrocarbon stream, separating the light hydrocarbon stream into a carbon dioxide-rich stream and a carbon dioxide-lean stream, and feeding the carbon dioxide-lean stream into a hydrocarbon sweetening process, thereby increasing the processing capacity of the hydrocarbon sweetening process compared to the processing capacity of the hydrocarbon sweetening process when fed the hydrocarbon feed stream.

Abstract: The invention comprises a spacing element situated between a vapor-liquid contacting tray and a tray support to reduce the dead zone typically caused by the tray supports blocking of the perforations in the vapor-liquid contacting tray directly above the tray support.

Abstract: A novel method for connecting multiple existing columns which are retrofitted into vapor-liquid contacting devices with trays or packings suitable for the operation of a three-phase (vapor-liquid-liquid) extractive distillation column for aromatics recovery. The retrofitted columns are connected by a vapor transfer line to transfer the vapor phase from the top of the lower column to the bottom of the upper column, and by a liquid transfer line to transfer the liquid phase from the bottom of the upper column to the top of the lower column of the three-phase extractive distillation column.

Abstract: A process for rectificatively separating fluids including (meth)acrylic monomers in a rectification column by directly cooling the vapor including (meth)acrylic monomers rising to the top of the rectification column to form top condensate including (meth)acrylic monomers, the condensation space at the top of the column being separated from the region of the rectification column containing the separating internals only by at least one chimney tray from which the top condensate formed is removed from the rectification column, which includes effecting the direct cooling of the vapor in the condensation space in at least two spray zones which are spatially successive and are flowed through by vapor by spraying supercooled top condensate including added polymerization inhibitor, and the temperature of the sprayed supercooled top condensate becoming lower from spray zone to spray zone in the flown direction of the vapor.

Abstract: Improved processes and apparatus use a finishing column with a mid-cut that provides alkylbenzene products of high purity containing less than about 1 ppmw benzene and less than about 50 ppmw heavies while accommodating enhancements in the efficiencies and the capacities of the distillation train to recover alkylbenzene from alkylation reaction product and while enabling the use of catalytic treatments to reduce olefinic-component content.

Abstract: A process for working up by distillation the crude products obtained in the process according to DE-A 196 07 954 and containing 1,6-hexanediol (HDO), 1,5-pentanediol (PDO) or caprolactone (CLO) in order to obtain the corresponding pure products, the working-up by distillation being carried out in each case in a dividing wall column (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 section (2, 4) having a rectification section (2) and stripping section (4), and a take-off section (3, 5) having a stripping section (3) and rectification section (5), with feeding of the respective crude product HDO, PLO or CLO in the middle region of the feed section (2, 4) and removal of the high boiler fraction (C) from the bottom of the column, of the low boiler fraction (A) via the top of the column and of the medium boiler fraction (B) from the middle region of the take-off section (3, 5), or

Abstract: The invention relates to a distillation installation comprising a system of columns (1, 3) and means for conveying a flow (7, 9) that is to be separated into one column (1) in said system. According to the invention, at least one segment (A, D) of one column contains structured packings comprising packs having a non-modified interface if, in the operating segment, the rate ratio is below a rate ratio threshold, said rate ratio being the ratio between the real reflux rate and the minimum reflux rate of the segment, and/or the charge ratio is above a charge ratio threshold, said charge ratio being the ratio between a falling flow of liquid and the section of the segment. Moreover, at least one segment (C, G) of a column, which is designed to operate with a rate ratio above the rate ratio threshold and/or with a charge ratio below the charge ratio threshold, contains structured packings comprising packs having at least one modified interface.

Abstract: A distillation apparatus for subjecting a crude readily polymerizable compound to distillation under vacuum conditions to purify the same includes a distillation column and a vacuum generator, an exhaust gas conduit of the vacuum generator being connected to a connecting conduit therebetween through a pressure control valve. The purification method includes using the disclosed distillation apparatus and controlling the action of the pressure control valve based on a pressure of the distillation column, thereby controlling the amount of the exhaust gas to be introduced to control the pressure of the distillation column.

Abstract: A partition for a packed column or a tray column which can carry out separation and/or chemical reactions has at least two partition elements disposed one above another and/or one alongside the other in the same plane, at least one plug and/or clamp connector connecting together the partition elements, and a sealing profile between an inner surface of the column and an edge of the partition elements turned toward the column inner surface. A fastening device is provided for the partition on the column inner surface. Lateral fastening parts of the partition carry inserts of the column and/or column trays. These fastening parts are rectangular profiles having upper sides extending horizontally in the column.

Abstract: A new tray configuration for a distillation column that utilizes the entire column cross section area as active tray area for vapor/liquid contact. The new tray configuration has no downcomers and utilizes a liquid/vapor seal pan(s) located in the vapor space of the adjoining tray to collect liquid from the tray, provide entrained vapor disengaging, distribute liquid from one active tray to another and provide a liquid and vapor seal between contact trays.

Abstract: A control apparatus and control method for controlling the separation in a dividing wall distillation column of at least two feeds into at least three products is disclosed. The apparatus uses a temperature measuring device to measure the temperature of fluid in the column, a controller, and a means for adjusting the temperature of fluid in the column. The temperature measuring device may be on either side of the dividing wall or above or below the dividing wall, and more than one such device may be used. The apparatus and method may be used in the production of alkylaromatic hydrocarbons by alkylating aromatic hydrocarbons with olefinic hydrocarbons.

Abstract: Improved HETP is obtained in the operation of a distillation column containing trays with a packing of a porous container containing a particulate material intimately associated with a resilient component having at least 50 volume % open space, preferably at least 70 volume % positioned on the trays compared to the trays without the packing. The packing may contain a catalytic particulate material and the distillation may involve reaction and distillation of the reaction products. The particulate material may also be inert and the distillation of the conventional type to separate components in the distillation mixture without reaction.

Abstract: Countercurrent stripping pipe for removing volatile organic constituents from reaction products, having a column pipe (201) composed of a plurality of pipe sections (201a-d), in which trays (202) are arranged, connections (205, 208) for supplying and removing the reaction products and connections (206, 207) for supplying and removing at least one stripping agent in countercurrent to the reaction products. In accordance with the invention, a plurality of successive trays (202) in each case are joined to one another and form at least two inserts (211a-c) which can be removed from the column pipe (201).

Abstract: An assembly of trays in a divided wall column having an inner column wall, a dividing wall, and an interior space includes: a first tray having at least one radial downcomer adjacent the dividing wall and extending radially toward the inner column wall a first substantial distance, and a first liquid receiving area having a radial axis at a first angle to the dividing wall and extending radially toward the inner column wall a second substantial distance; and a second tray below the first tray, the second tray having at least one other downcomer having a radial axis at a second angle to the dividing wall and extending radially toward the inner column wall a third substantial distance, and at least one second liquid receiving area adjacent the dividing wall and extending radially toward the inner column wall a fourth substantial distance.

Abstract: A perforated tray without downcomer having only a small deviation between the opening ratio based on the diameter of a column and the actual opening ratio and a perforated tray column without downcomer formed by disposing such perforated trays without downcomer are provided. The perforated trays without downcomer are characterized by having a ratio of (A)/(B) in the range of 1.1-1.5, wherein A denotes the opening ratio found from the standard pitch between centers of holes and (B) denotes the opening ratio based on the diameter of a column.

Abstract: A gas-liquid contacting tray equipped with downcomers having sidewalls with liquid outlet openings, which openings are provided with a liquid guiding device such as a lip or a spout. In one embodiment the contacting tray constitutes an upper tray having downcomer(s) which are arranged in parallel, and symmetrically, with downcomers on a lower tray.

Abstract: The invention relates to an apparatus for the production of butylacetate by esterification of acetic acid with butanol in the presence of a solid acidic catalyst in which distillatory separation of components runs simultaneously with esterification. Thus, acetic acid and butanol are introduced in defined amounts and in the molar ratio 1:1 to 1:10 into a system, in which the reaction and the distillatory separation proceeds in three zones. The reaction together with distillatory separation of the components with different boiling points run in the reaction zone, while only distillation takes place in lower and upper separation zones. A volatile mixture is separated in the upper separation zone, from which, after being cooled at 5 to 80° C., water and organic phases are separated, the latest being refluxed into the system. The ratio of the feed amount to the organic phase reflux amount is 1:1 to 1:20, the reflux amount representing 60 to 100% of the whole amount of the organic phase.

Abstract: An apparatus for recovering ethylene from a hydrocarbon feed stream, where the apparatus is a single distillation column pressure shell encasing an upper region and a lower region. The upper region houses an ethylene distributor rectifying section and the lower region houses a C2 distributor section and an ethylene distributor stripping section. Vapor passes from the lower region into the upper region, and liquid passes from the upper region to the lower region. The process for recovering the ethylene is also disclosed. The hydrocarbon feed stream is introduced into the C2 distributor section, and after a series of stripping and refluxing steps, distinct hydrocarbon products are recovered from the C2 distributor section, the ethylene distributor stripping section, and the ethylene distributor rectifying section, respectively.

Abstract: A chimney tray for a column for thermal treatment of a liquid. The chimney tray includes a total take-off of liquid by a drain connection arranged at an edge of the chimney tray, and having one or more drain channels having a gradient in a direction of the drain connection, and having a gradient in a direction of the one or more drain channels.

Abstract: A system and process for the recovery of oil from the pyrolysis of material containing hydrocarbons such as shredded vehicle tires. The system utilizes a pair of sequentially positioned packed towers to recover at least 95% of the oil contained in the pyrolysis gases. The first packed tower operates above the dew point of the water vapor in the pyrolysis gases to insure that no water is condensed and obtain a primary oil fraction having oil with a high flash point of about 60° C. or greater and a primary vapor fraction containing additional oils, fuel gases and water vapor. The primary vapor fraction is fed to the second packed tower which operates below the dew point of the water vapor to condense the water and oil having a low flash point of 34° C. or below, and provide a secondary vapor fraction containing valuable fuel gases.

Abstract: A dividing-wall column having a dividing wall which is essentially disposed along the long direction of the column is proposed, which divides the column interior into a feed part, a take off part, an upper shared column part and a lower shared column part, with feed in whole or in part in the vaporous state of a mixture to be separated between the upper region of the feed part and the lower region of the feed part and/or side stream take off in whole or in part in the vaporous state between the upper region of the take off part and the lower region of the take off part, where if feed is in whole or in part in the vaporous state the cross-sectional area of the upper region of the feed part is increased by plane-parallel displacement of the dividing wall toward the upper region of the take off part, and/or if the side stream take off is in whole or in part in the vaporous state, the cross-sectional area of the lower region of the take off part is increased by displacement of the dividing wall toward the lower r

Abstract: A process and a device for the catalytic hydrolysis of a carboxylate, e.g., methyl acetate, ethyl acetate, i- or n-propyl acetate, i- or n-butyl acetate, allyl acetate and methyl formate, into the corresponding carboxylic acid and alcohol, by a combination of a pre-reactor and a reactive distillation column are disclosed. By the combination of a pre-reactor and a reactor distillation column, the conversion ratio can be substantially improved. The device can compensate for fluctuations in the supply quantity or in the composition of the feed flow. The product composition can also be controlled in a wide range.

Abstract: The invention relates to a method for producing a highly pure, aqueous hydroxylamine solution by distilling an aqueous solution, devoid of salt, of a hydroxyl ammonium salt in a plate column comprising at least two mechanical plates. Said method is characterised in that packing bodies are arranged between at least two plates of the plate column over the cross-section of said column.

Abstract: In a dividing wall column comprising as segments a) an upper column region (6), b) an inflow section (7), c) an offtake section (8) and d) a lower column region (9), the inflow section b) (7) and the offtake section c) (8) are separated from one another laterally by a dividing wall (10) fixed in the column and the dividing wall (10) is located between the upper column region a) (6) and the lower column region d) (9). The present invention provides for the dividing wall (10) to be constructed at least partly of an elastic material, the dividing wall (10) to have a slightly overdimensional width and the dividing wall (10) to be fixed in the column by the dividing wall exercising an elastic recovery force on the interior wall of the column. The dividing wall can easily be installed in, in particular, relatively small columns.

Abstract: A process for preparing a salt-free aqueous hydroxylamine solution by distilling an aqueous solution of a hydroxylammonium salt and a base in a tray column having at least two mechanical trays, wherein random or structured packings are located above at least one tray of the tray column over the cross section of the column.

Abstract: Liquid is distributed substantially uniformly in a liquid-vapour separation column 22 located on an off-shore floating platform using a liquid distributor 24 characterised in that (i) the distance between the two apertures that are furthest apart in the or each secondary distributor is such that the liquid distributor provides, at each angle of tilt, a standard deviation of liquid flow rates through the apertures of the or each secondary distributor that is less than a first predetermined maximum for all angles of tilt; and (ii) the difference in flow rate between the aperture having maximum liquid flow and the aperture having minimum liquid flow in the or each secondary distributor at each angle of tilt is less than a second predetermined maximum for all angles of tilt.

Abstract: This invention relates to a continuous process for the preparation of silane by catalytic disproportionation of trichlorosilane in a reactive/distillative reaction zone having a catalyst bed of catalytically active solid.

Abstract: In a distillation apparatus, a production process and a purification method of readily polymerizable compounds, a problem of the invention is to solve a serious plugging problem in a large-sized distillation column as in the commercial equipment and to provide an apparatus and a method for distilling and purifying a readily polymerizable compound stably over a long period of time.

Abstract: A process for reacting a first component with itself or a second component to produce a third component in which a first material comprising a first component or said first component and a second component is fed to divided wall column having a catalytic distillation structure in at least one of the separate vertical sections of the divided wall column where concurrently: (1) a first component alone or with a second component is contacted with a catalytic distillation structure in a distillation reaction zone thereby catalytically reacting at least a portion of the first component with itself or with the second component to form a product and (2) a first mixture comprising the first component and the product or the first component, the second component and the product; and withdrawing the product from the distillation column reactor; while within the column concurrently with the catalytic reaction and fractionation a second mixture is fractionated, which contains the first component and the product or first a

Abstract: Thermal separating process between at least one gaseous and at least one liquid stream, of which at least one comprises (meth)acrylic monomers, in a separating column whose separating internals are mass transfer trays, in which the liquid stream is polymerization-inhibited and used for spraying the surface of the separating column, and internal surfaces which are in the shadow region of the spraying are removed from the shadow region by covering.

Abstract: This invention exploits the concept of Staged Heat and Mass Transfer (SHMT) to enhance operability, control robustness and intrinsic safety in preventing corrosion while recovering material, and energy if desirable, in process waste streams. Two applications illustrating the improvements based on the SHMT concept are given. One application illustrates novel design features to recover vent from a steam boiler deaeration system, positively eliminating the risk of oxygen and carbon dioxide accumulation in deaerator. The other application illustrates process adaptations of the same SHMT concept to recover steam, steam condensate, and fugitive emissions involving particulate materials if desirable, from any process vents from vessels that are opened to the atmosphere. Again, without the risk of corrosion by atmospheric oxygen.

Abstract: The invention relates to a method for producing a highly pure, aqueous hydroxylamine solution by distilling an aqueous solution, devoid of salt, of a hydroxyl ammonium salt in a plate column comprising at least two mechanical plates. Said method is characterised in that packing bodies are arranged between at least two plates of the plate column over the cross-section of said column.

Abstract: Partitions for columns for the separation of components or chemical reactions are assembled from plates or wall elements provided with plug and clamp connectors along respective edges and formed by strips so that the partitions can be easily and safely assembled and disassembled.

Abstract: An energy efficient series of mass and energy integrated reactive distillation columns and distillation columns are used to effect the production of diaryl carbonate. Utilizing the method or apparatus of the invention facilitates high diaryl carbonate production rates, and convenient recovery of unreacted starting materials and side-reaction products for recycle within the process for making diaryl carbonates or utilization in parallel reactions such as the manufacture of dialkyl carbonates. The method makes use of three reactive distillation columns and two rectification columns which are joined by a plurality of lines for transferring reactants and/or products into and out of the columns.