Abstract: Vapor-liquid contacting apparatuses, for example reactors and distillation columns (as well as reactive distillation apparatuses), comprising a vessel with one or more vortex contacting stages, are described. The one or more stages provide high interfacial area for the effective contacting of the different phases, in addition to the effective disengagement of these phases after contacting.

Abstract: A process for the separation of the aromatic compounds benzene, toluene and xylene from an aromatics-containing reformate gasoline and pyrolysis gasoline or a coke-oven light oil or an aromatics-containing refinery stream, in which the aromatics are separated by an extractive distillation uses a novel solvent combination made up of the compounds n,n?-diformyl piperazine or 2,2?-bis-(cyanoethyl)ether in a combination with n-formyl morpholine as a second solvent for extractive distillation so that the solvent combination obtained shows a higher selectivity with regard to the aromatics to be extracted so that a lower solvent load is required. The aromatics-containing feed mixture is first submitted to a pre-distillation so that the obtained fraction has a narrow boiling point range. This fraction is then submitted to an extractive distillation in a first column, in which an aromatics-lean head product of predominantly paraffinic hydrocarbons is obtained as well as an aromatics-enriched bottom product.

Abstract: The present invention provides a (meth)acrylic acid collecting method for collecting a (meth)acrylic acid from a mixed gas that includes an organic byproduct, a steam, and a (meth)acrylic acid that are generated in a production reaction of the (meth)acrylic acid, which includes the steps of a) contacting the mixed gas that includes the organic byproduct, the steam, and the (meth)acrylic acid with a (meth)acrylic acid absorption solvent to obtain a gas that includes the organic byproduct and the steam and the (meth)acrylic acid containing solution while the gas and the (meth)acrylic acid containing solution are separated from each other; b) contacting the gas that includes the organic byproduct and the steam that are obtained in the step a with the organic byproduct absorption solvent to obtain the gas that includes the steam and the organic byproduct containing solution while the gas and the organic byproduct containing solution are separated from each other; c) supplying the gas that includes the steam that

Abstract: An improved process for the removal and recovery of sulfur from a sour hydrocarbon stream is provided. The process includes contacting a sour hydrocarbon stream that includes hydrogen sulfide and carbon dioxide with a lean absorbent to produce a rich absorbent stream. The rich absorbent stream is separated and the recovered acid gas is contacted with a second absorbent to produce a second rich absorbent stream. A portion of the second rich absorbent is recycled to the separation step. A second portion of the second rich absorbent is separated to produce an acid gas product stream. Recycling a portion of the second rich absorbent to the first separation step shifts the equilibrium of the process, resulting in an acid gas product stream having an increased hydrogen sulfide:carbon dioxide ratio.

Abstract: A packing structure according to the invention for a fluid contacting column forms a volume comprising an ordered arrangement of bundles of tubes of diameter ranging between 5 and 50 mm. The walls of the tubes comprise orifices which promote circulation and mixes fluids in the structure. The orifices are inscribed in rectangles whose sides range between 2 and 45 mm, and each one of the orifices extends over a surface area greater than 2 mm2.

Abstract: The invention relates to a method for cooling rising vapor (3) in a desorption column (2) by means of a condenser, which is situated at the head of the desorption column, is configured as an indirect heat exchanger and is traversed by a coolant (1). According to said method, the coolant enters at the bottom of the condenser (1) and flows upwards through conduits (8) that are arranged vertically in the condenser. The coolant is enriched with hydrogen sulphide prior to its entry into the condenser (1) and after the absorption of heat, escapes as an overflow (6) from the top of the condenser (1) through upper openings (10) of the conduits (8). The invention also relates to a desorption column (2) for carrying out said method.

Abstract: A method of using an ionic liquid as solvent in headspace gas chromatography.

Abstract: A top temperature T1 of a distillation tower 1 is held below a liquefying temperature of a light fraction by returning a part of an exhaust gas W, which is cooled by a condenser 5, to the upper zone of the distillation tower 1. A bottom temperature T2 is raised up to 300° C. at highest by returning a part of a liquid product P from a re-boiler 3 to a lower zone of the distillation tower 1. When a liquid hydrocarbon L comes in countercurrent contact with a stripping gas G inside the distillation tower 1 with the temperature profile that an inner temperature gradually falls down along an upward direction, mercury is efficiently transferred from the liquid L to a vapor phase without effusion of the light fraction in accompaniment with the exhaust gas W.

Abstract: A process and an apparatus separate a volatile component from a substance mixture (raw product). The substance mixture is heated, the volatile component is at least partly evaporated and then the vapor formed is condensed. To improve the separating action, the condensate, in the region of the point of condensation, is contacted with a liquid in which the condensate dissolves.

Abstract: Processes comprising: providing a mixture comprising monoethylene glycol and diethylenetriamine; and subjecting the mixture to extractive distillation with a diethylenetriamine-selective solvent comprising triethylene glycol to provide a first stream comprising monoethylene glycol and a second stream comprising diethylenetriamine; wherein the first stream is substantially free of diethylenetriamine, and wherein the second stream is substantially free of monoethylene glycol.

Abstract: A distillation apparatus for subjecting a crude readily polymerizable compound to distillation under vacuum conditions to purify it, the distillation apparatus having a distillation column and a vacuum generator and an exhaust gas conduit of the vacuum generator connected to a connecting conduit therebetween through a pressure control valve. A method provides purifying of a readily polymerizable compound by subjecting a crude readily polymerizable compound to distillation under vacuum conditions to purify it, the method including using a distillation apparatus having a distillation column and a vacuum generator and an exhaust gas conduit of the vacuum generator connected to a connecting conduit therebetween through a pressure control valve and controlling the action of the pressure control valve based on a pressure of the distillation column.

Abstract: The present invention provides a method and a system for stripping volatile compounds such as ammonia from liquids. Part of the ammonia is stripped from the liquid in a system having a shunt through which liquid such as e.g. fermented biomass can be diverted in the form of a side stream in liquid contact with a main fermentor(s). The stripper system is connected to an evaporator. In the evaporator aqueous liquid is heated at a pressure below atmospheric pressure whereby vapor is developed at a temperature below 100° C. The vapor from the evaporator is directed to the liquid medium containing ammonia and this results in ammonia being stripped from the liquid and transferred to the vapor phase. The vapor phase is condensed in a first condenser at a low pressure, and the liquid thus obtained is further treated in a stripper unit at a higher pressure.

Abstract: The invention relates to a process for separating NH3 from a mixture containing NH3, CO2 and H2O which comprises an NH3 rectification step carried out in a NH3 separation device to which one or more streams containing NH3, CO2 and H2O including the mixture, are supplied, with a stream consisting substantially of gaseous NH3 being formed in the NH3 separation device, separated from the mixture and discharged. In the process according to the invention a condensation step is carried out on at least one of the stream consisting substantially of gaseous NH3 or the one or more streams containing NH3, CO2 and H2O supplied to the NH3 separation device, in which at least a part of the existing CO2 is converted to a liquid phase.

Abstract: A process for distillative removal of ammonia from solutions (I) which include a lactam and ammonia comprises effecting said removal in a distillation apparatus (a) at an absolute pressure of less than 10 bar.

Abstract: (Meth)acrylic acid is worked up in the presence of at least one stabilizer by a process in which a stabilizer-containing mixture originating from the working-up and substantially freed from (meth)acrylic acid is passed into a distillation apparatus and a stabilizer-containing low boiler stream obtained from said apparatus is recycled to the working-up.

Abstract: According to the invention, the vapor is taken from the condensation chamber of the dehydrator and, prior to being compressed and at a temperature substantially equal to 100° C., it is caused to pass in succession through a series of purifiers, and in each of the purifiers it is forced through rain containing a purifying solution, at least one of the rain solutions being water, another containing an acid, and another containing a base. The invention is applicable to treating the vapor that results from dehydrating a variety of kinds of matter, such as farmyard manure, in particular.

Abstract: A process for distillative removal of ammonia from solutions (I) which include a lactam and ammonia comprises effecting said removal in a distillation apparatus (a) at an absolute pressure of less than 10 bar.

Abstract: The present invention is a distillation system with individual fractionator tray temperature control, with the use of either a heating element or a cooling element, and in some preferred embodiments, the use of both a heating element and a cooling element in a plurality of fractionator trays. There is at least, and typically more than one distillation column having a plurality of fractionation trays, and having feed input, liquid removal, and vapor removal with the plurality of trays including at least one of a heating element and a cooling element. Controls are included for separate control of each of the heating element(s) and/or said cooling element(s). These controls may be regulated by a programmable microprocessor, and feedback from temperature sensors may be employed to provide discrete tray-by-tray temperature controls.

Abstract: The air B supplied from the air-sending device 23, constructing the recycling device 1 of the material to be processed, is kept in contact with the coolant A absorbed into or attached to the belt 4 for being dipped into liquid, wherein the air B inspired by the discharging device 49 is kept in contact with the coolant A dripping down or passing the plate 42 on which liquid flows down so that water from the coolant A will be evaporated when drying natural, thus increasing the density of ethylene glycol. The coolant A condensed to a given density is dripped down from the belt 4 for being dipped into liquid and the plate 42 on which liquid flows down so that, upon being reserved in the liquid recovering container 3 or the liquid reserving container 43, the coolant A, which is already recycled, is recovered from the container 3, 43.

Abstract: A process for concentrating spent sulphuric acids particularly sulphuric acids which arise during the nitration of hydrocarbons with nitric acid in the presence of sulphuric acid, wherein single- or multi-stage concentration is effected under vacuum.

Abstract: The present invention pertains to the field of chemical and oil refining technology. In particular, the invention relates to the vacuum distillation of liquid mixtures and relates directly to the separation of liquid mixtures. The main field of application of the invention is rectification of oil stock in the petrochemical industry. The objective of this invention is to reduce power consumption required for generating a vacuum in mass-transfer columns while improving the quality of target products, reducing environmental pollution and increasing the efficiency of separation. According to the invention, a vacuum in a mass transfer column is generated due to condensation of outgoing vapors and evacuation of non-condensable gas-vapors by a vacuum-producing system, which is connected to a vacuum pump and composed of an absorber, a phase separator and a cooler, connected in series.

Abstract: In a process for the separation by rectification of (meth)acrylic acid from a mixture containing (meth)acrylic acid and an inert hydrophobic organic liquid having a boiling point higher than that of (meth)acrylic acid as main constituents and also lower aldehydes as secondary constituents, a primary amine and/or a salt thereof are added.

Abstract: A process for the purification of an aqueous alkanolamine which process involves subjecting the alkanolamine to a distillation process carried out in one or more film-type evaporators and involves at least two steps, wherein in the first step water is removed from the aqueous alkanolamine and in the second step the de-watered alkanolamine is further purified.

Abstract: A phenolic-rich pyrolysis oil is produced by pyrolysing lignocellulosic material at a temperature of no more than about 550.degree. C under an absolute pressure of no more than about 50 kPa to produce pyrolysis vapors, and condensing the pyrolysis vapors to obtain a condensate consisting of a phenolic-rich pyrolysis oil having a dew point of about 65 to about 75.degree. C. under an absolute pressure of about 15 to about 20 kPa. Such a phenolic-rich pyrolysis can be directly used in making phenol-formaldehyde resol resins.

Abstract: Highly purified ammonia for use in semiconductor manufacturing is prepared on-site by drawing ammonia vapor from a liquid ammonia reservoir, passing the vapor through a filter capable of filtering out particles of less than 0.005 micron in size, and scrubbing the filtered vapor in a high-pH aqueous scrubber.

Abstract: A process for purifying a raw natural gas stream is provided by contacting the gas stream with an absorbant to remove water and hydrocarbon impurities, separating the water and hydrocarbon impurities and absorbant from the gas stream, separating the absorbant from the water and hydrocarbon impurities to provide a liquid absorbant stream and a water vapor and hydrocarbon vapor stream, condensing the water vapor and a portion of the hydrocarbon vapor stream to provide a mixed liquid/vapor stream, passing the mixed stream through a pump capable of pumping a mixed stream, and disposing of the thus-reduced volume, higher pressure, mixed stream. One aspect of the invention provides for the reintroduction of the mixed stream to the process with the raw natural gas, thereby eliminating volatile organic compound disposal concerns.

Abstract: An improved urea recovery process is presented. In the improved process, multiple vacuum rated surface condensers used to condense water vapor evolved during urea vacuum evaporation/concentration are replaced by a direct contact cooler/absorber to obtain substantial capital and utility cost savings. Improved heat exchange efficiency of the present process significantly reduces cooling water usage in comparison to the surface condensers.

Abstract: A method of recycling and purifying cleaning chemicals used in the production of semiconductor circuits and containing hydrofluoric acid and or hydrochloric acid. Recycling of such chemicals is accomplished using separation and reconstitution steps Hydrofluoric acid and hydrochloric acid cannot be distilled directly from a chemical solution as they form azeotropes with water. A low vapor pressure substance such as sulfuric acid or phosphoric acid is used to break the azeotrope while increasing the purity of the recovered chemicals and decreasing disposal problems. The method is useable at the point of use of the chemicals.

Abstract: Volatile acids containing metal salt impurities, such as metal pickling solutions-are regenerated by a process in which the acid is subjected to sulfuric acid distillation. Resulting volatile acid vapor is condensed and recycled to the pickle tank, while the residual acid mixture is treated in an acid sorption unit, preferably of the acid retardation type. Acid sorbed in the acid sorption unit is periodically eluted with water and recycled, while metal impurities are rejected in a deacidified by-product solution.

Abstract: Process and apparatus for reclaiming or concentrating waste aqueous solutions of gas treating chemicals, such as alkanolamines, used for removing acid components or water vapor from natural gas. The process involves heating the waste solution under a high vacuum to form a vapor and a liquid residue. The temperature and vacuum can be varied to form a vapor consisting mainly of water vapor or a vapor containing both water vapor and vaporized gas treating chemical. The vapor is subsequently condensed or passed through a wash column to produce a concentrated solution. The liquid residue is heated by passing it through a single pass, generally co-current heater at a rate which avoids localized overheating of a liquid to a temperature above the decomposition temperature of the gas treating chemical. The heated liquid residue is then used to heat the feed waste solution by being thoroughly mixed with it, thus avoiding overheating of the feed solution.

Abstract: Disclosed is a method and apparatus for recovering acetic acid from an acetic acid/water waste stream which includes a dehydration column into which the stream is fed and a liquid-liquid extraction system for recovering acetic acid from the condensate of the overhead stream of the dehydration column. Optionally, low pressure and/or high pressure absorber systems are provided to process vapor and/or liquid streams associated with the recovery system and/or the plant in which the acetic acid is used to further the recovery of acetic acid and reduce atmospheric pollution.

Abstract: A continuous process for the extraction of halogenated hydrocarbons from a dilute, halogenated hydrocarbon-containing aqueous fluid, in high efficiency, while dramatically reducing the stripping medium requirement for the extraction and without substantially increasing the amount of halogenated hydrocarbons discharged to the atmosphere.

Abstract: A process is provided for separating high purity alkyl glycolate from a gaseous reaction mixture resulting from the catalyzed gas phase oxidation of alkyl glycolate. A hot solvent which is immiscible with water but selectively dissolves alkyl glycolate and alkyl glyoxylate is brought in contact with the gaseous reaction mixture, and water and alcohol vapors are removed from the hot solvent. The alkyl glyoxylate is removed from the solution by a first distillation and the alkyl glycolate and solvent are then separated in a second distillation.

Abstract: A method and apparatus for deaerating a suspension of solids in a liquid such as, for instance, papermaking stock. The suspension is flashed in a vacuum tank connected to a condenser. The vapor released when the suspension is flash cooled in the tank is condensed into an absorption liquid having a higher temperature but a lower vapor pressure than that of the released vapor on a heat exchange surface of the condenser. The flash cooled suspension is used as the cooling medium in the condenser. The diluted absorption liquid is regenerated in an evaporator and recirculated to the condenser. The vapor released in the evaporator can be condensed to heat the suspension further or for other suitable heating purposes.

Abstract: Aqueous hydrochloric acid of very high purity can be obtained in a process for purifying crude aqueous 5 to 20 wt. % hydrochloric acid. In the purification, process water or a water/HCl mixture is evaporated from the crude aqueous hydrochloric acid at a pressure of from 0.01 to 1.0 bar and a temperature of from 10.degree. to 100.degree. C. until a crude, azeotropic mixture of water and HCl is obtained. The crude, azeotropic mixture of water and HCl is distilled in a distillation apparatus at a pressure of from 0.1 to 1.5 bar and a temperature of from 50.degree. to 110.degree. C. A purified gaseous, azeotropic mixture of water and HCl is recovered from the head of the distillation apparatus and a liquid mixture is left at the bottom of the distillation apparatus. The liquid mixture which is left at the bottom of the distillation apparatus is distilled at a pressure of from 0.5 to 2.5 bar and a temperature of from 80.degree. to 130.degree. C.

Abstract: The invention relates to a process for the isolation of vinyl acetate which involves not combining the bottom product of the recylced gas washings with the water-saturated vinyl acetate but rather introducing it to further multiple distillation columns from the gas mixture formed in the reaction of ethylene with acetic acid and oxygen over catalysts containing palladium or palladium compounds in the gas phase.

Abstract: An apparatus and method for reprocessing waste piranha containing contaminated H.sub.2 SO.sub.4 from, for example, a semiconductor processing operation is described. The apparatus and method include a first distillation flask which is maintained under a substantial vacuum. The first distillation flask includes a first column packed with a column packing material and an input pipe for refluxing to retard loss of H.sub.2 SO.sub.4 in the first distillation. The second distillation flask boils off substantially pure H.sub.2 SO.sub.4 and provides for a continuous automatic purge of the contaminants from the second distillation flask thus improving the purity of the H.sub.2 SO.sub.4. The substantially pure H.sub.2 SO.sub.4 flows through a column which is coupled to a condenser which condenses substantially pure H.sub.2 SO.sub.4.

Abstract: A process for the production of pure dimethylether by feeding the dehydration product from a dimethylether-synthesis reactor into a distillation column for the production of pure dimethylether at defined trays of this column and withdrawal of pure dimethylether and a fraction containing contaminations at defined trays of the same column, whereby in addition washing liquids and bases can be added.

Abstract: A process for the concentration of ethylene oxide in an impure solution thereof including adding the solution and steam to a distillation column, recovering the gaseous stream therefrom containing ethylene oxide, and progressively condensing the steamed solution in at least two heat exchangers arranged in series, with the absolute pressure of the distillation column and of the exchangers being between about 1.5 and 6 bars and the temperature of the cooling fluid of the last exchanger being between about 5.degree. C. and a maximum temperature 5.degree. C. below the temperature of condensation of pure ethylene oxide at the pressure used.

Abstract: Removal of aluminum and iron impurities is accomplished using an absorbing column containing potassium or sodium chloride, producing an aluminum and iron chloride-rich bottoms product and purified Zr(Hf)Cl.sub.4 vapor at the top of the column. This invention is a continuous process for removing impurities of iron or aluminum chloride or both from vaporous zirconium chloride (or hafnium chloride or a mixture thereof). When iron is being removed from zirconium tetrachloride using potassium chloride, the process comprises: introducing impure zirconium chloride vapor into a middle portion of an absorbing column containing a potassium chloride-containing molten salt phase, the molten salt phase absorbing the iron chloride impurity to produce a zirconium chloride vapor stripped of iron chloride in the top portion of the column; introducing potassium chloride into a top portion of the column; controlling the top portion of the column to between 300.degree.-375.degree. C.

Abstract: This is a process for removing phosphorus oxychloride from a complex of zirconium or hafnium chloride and phosphorus oxychloride utilizing a lithium-potassium chloride molten salt absorber vessel displacing phosphorous oxychloride from the complex, with a condenser which has the complex of zirconium or hafnium chloride and phosphorus oxychloride as the condensing fluid to scrub zirconium or hafnium chloride from the phosphorus oxychloride vapor released from the complex. The process uses at least one separate vessel to strip the zirconium or hafnium chloride from the lithium-potassium chloride molten salt.

Abstract: Methods for removing volatile organic substances from water employ flash vaporization techniques. The methods comprise providing water which contains volatile organic substances and is at a pressure of at least about 35 psig, releasing the water into a vacuum chamber maintained under a vacuum in the range of about 1 to about 5 psia, removing resulting vapors from the chamber, and collecting liquid water from the chamber. At least a portion of the volatile organic substances originally contained in the water are removed as vapors from the vacuum chamber.

Abstract: The invention relates to a process for the isolation of vinyl acetate from a gas mixture containing vinyl acetate, ethyl acetate, water and carbon dioxide formed in the reaction of ethylene with acetic acid and oxygen in the gas phase over catalysts containing palladium or palladium compounds. The gas mixture leaving the reaction zone is passed into a distillation column and the gas mixture leaving the top thereof is cooled. The gas which is not condensed during the cooling is washed with acetic acid in a washing column, an acetic acid solution containing vinyl acetate being obtained. The bottom product from the distillation column is passed to a second distillation column and a side stream containing ethyl acetate is removed from an enrichment zone above the bottom thereof, all or some of the bottom product from the second distillation column, which product chiefly consists of acetic acid, being used for the wash in the washing column. The top vapor of the second distillation column is cooled.

Abstract: The instant invention relates to a process for the purification of dimethylether, which contains impurities, by feeding a mixture which contains the dimethylether at specific trays to a distillation column and withdrawal of the dimethylether and of impurities at specific trays of the same column.

Abstract: An aqueous effluent is supplied to a stripping column (total stripping column) from which a mixture that is rich in NH.sub.3, CO.sub.2 and H.sub.2 S is withdrawn as a head product. In at least one additional stripping column the mixture is separated into a mixture which is rich in NH.sub.3 and a mixture which is rich in the sour gaes CO.sub.2 and H.sub.2 S. The mixture which is rich in NH.sub.3 is scrubbed with liquid ammonia. The overhead product from the total stripping column is cooled in a condenser under a pressure of 1 to 7 bars and is thus transformed into a liquid phase to such an extent that the liquid phase contains 70 to 100% of the NH.sub.3 which has been supplied to the condenser. The liquid phase is supplied at a temperature of 30.degree. to 90.degree. C. to a second stripping column (NH.sub.3 stripping column), which is operated under a pressure of 1 to 4 bars and from which a gas mixture that is rich in NH.sub.3 is withdrawn as a head product.

Abstract: Apparatus for concentrating and dehydrating maleic acid to form maleic anhydride, comprising: at least a first and a second vertical, independent and distinct, falling thin-film, multitubular evaporators of the static type arranged in series, wherein the first thin-film multitubular evaporator of the static type has an upper part and a lower part and includes a feedpipe at the upper part and a discharge pipe at the lower part; a separator connected by its sidewall to the discharge pipe from the first evaporator and including a first discharge pipe at the upper portion thereof and a second discharge pipe at the lower part; the second thin-film multitubular evaporator of the static type having a feedpipe having an upper part and a lower part connected to the second discharge pipe from the separator and including a discharge pipe only at the lower part thereof; a boiler having an upper part and a lower part, said upper part of said boiler being connected to and in open communication with the lower portion of the

Abstract: A process for the separation of water from a water-containing mixture of azeotrope, with an extractant which removes water from the mixture or azeotrope, recovery of the non aqueous portion of the mixture or azeotrope as a product, and regeneration of the extractant for reuse by the removal of water therefrom. A feature thereof is that residual water can be removed from the extractant, and the extractant regenerated for reuse by contacting the heated extractant with a portion of the same product from which the water has been removed; or, the extractant can be regenerated in the process by contact with an inert gas which has been dried in the process. The water-containing mixture or azeotrope is preferably contacted with a portion of the vaporous product to recover the heat of condensation for use in the process.

Abstract: A fluorinated carbonyl compound ##STR1## where x is 2 or 3 and A represents CF.sub.3 or H, coexisting with hydrogen fluoride in a mixed gas is purified by first adjusting the temperature of the mixed gas to 100.degree.-300.degree. C. to cause decomposition of a usually coexisting complex of the fluorinated compound with HF and then bringing the hot mixed gas into contact with concentrated sulfuric acid maintained at 10.degree.-40.degree. C. Almost the entire amount of HF is absorbed in sulfuric acid and subsequently recovered, while the purified compound neither dissolves in sulfuric acid nor reacts with HF present in sulfuric acid.

Abstract: A method of treating a liquid containing radioactive contaminants to produce a vapor containing a reduced amount of radioactive contaminant wherein continuous evaporation is effected in a vessel comprising two interconnected sections, one surrounding the other, the degree of evaporation in the inner section being greater than in the outer section thereof resulting in a greater concentration of radioactive material in the inner section.The outer evaporation section acts as a shield to reduce the release of radiation from the concentration of radioactive materials in the inner section.

Abstract: There is disclosed the process for the separation of the clay particles (ash) from coal particles by the use of two immiscible liquids followed by the separation and removal of the liquids from the solids.