Abstract: This invention relates to methods for producing chemical products, wherein the one or more feed materials are reacted to form a chemical product or a chemical composition. The invention further relates to plants for performing such methods, said plants being designed in such a way that, during an interruption of the methods, no input of at least one feed material into the reaction occurs and the plant parts not affected by a revision measure, maintenance measure, repair measure, or cleaning measure are operated in so-called re-circulation mode. It is thereby achieved, among other things, that only the affected plant part needs to be shut down for the time of the measure, which can be advantageous with regard to the productivity and economy of the method and the quality of the produced products. Finally, the invention relates to methods for operating plants in the event that individual plant parts are taken out of service.

Abstract: A crude product stream of 1,4-butandiol and one or more of ?-butyrolactone, 2-(4-hydroxybutoxy)-tetrahydrofuran, 4-hydroxybutyl(4-hydroxybutyrate), and 3-(4-hydroxybutoxy)-tetrahydrofuran is supplied to a first distillation column. A side-draw of 1,4-butanediol and light components is removed, with the light components including at least some of those produced by reaction in the first distillation column. The stream is passed to a hydrogenation zone and subjected to hydrogenation in the presence of a hydrogenation catalyst. A 1,4-butanediol product stream having a reduced content of 2-(4-hydroxybutoxy)-tetrahydrofuran is recovered and passed to a second distillation column operated such that (4-hyroxybutyl)-4-hydroxybutyrate is removed as a bottom stream and a 1,4-butanediol stream is removed as overhead. The overhead stream removed is passed to a third distillation column and a purified 1,4-butanediol stream is recovered.

Abstract: A system for carbonating a personalized beverage may comprise a base container including at least one sidewall defining a liquid storage area, and a carbon dioxide storage member configured to be sealingly coupled to said base container. The system may further comprise a carbon dioxide cartridge configured to selectively release carbon dioxide when engaged with said carbon dioxide storage member, and wherein said carbon dioxide storage member further comprises a pressure regulator configured to, when actuated, release the said carbon dioxide from said carbon dioxide cartridge at a rate configured to carbonate a beverage within said liquid storage over a period of time greater than 6 hours and less than 36 hours.

Abstract: A process for recovering butanol from a mixture of a water-immiscible organic extractant, water, butanol, and optionally a non-condensable gas, is provided. The butanol is selected from 1-butanol, isobutanol, and mixtures thereof. An overhead stream from a first distillation column is decanted into two liquid phases. The wet butanol phase is refined in a second distillation column; the aqueous phase is returned to the first distillation column. A portion of the wet butanol phase from the decanter is also returned to the first distillation column. The extractant may be C7 to C22 fatty alcohols, C7 to C22 fatty acids, esters of C7 to C22 fatty acids, C7 to C22 fatty aldehydes, and mixtures thereof.

Abstract: A process for recovering butanol from a mixture of a water-immiscible organic extractant, water, butanol, and optionally a noncondensable gas, is provided. The butanol is selected from 1-butanol, isobutanol, and mixtures thereof An overhead stream from a first distillation column is decanted into two liquid phases. The wet butanol phase is returned to the first distillation column as reflux. A bottom stream from the first distillation column is refined in a second distillation column to obtain a second overhead stream and a second bottoms stream. The extractant may be C7 to C22 fatty alcohols, C7 to C22 fatty acids, esters of C7 to C22 fatty acids, C7 to C22 fatty aldehydes, and mixtures thereof.

Abstract: A modular portable evaporator system for use in a Steam Assisted Gravity Drainage (SAGD) systems having an evaporator, with a sump including an oil skimming weir, a short tube vertical falling film heat exchanger including an outer shell containing short tubes provided for lower water circulation rate. The system further having external to the evaporator, a compressor for compressing evaporated steam from the tube side of the heat exchanger and routing to the shell side of the same exchanger, a distillate tank to collect hot distilled water, a recirculation pump to introduce liquids from the sump into the heat exchanger and an external suction drum protecting the compressor from liquid impurities. The evaporator system receives produced water from the SAGD process into the sump and provides cleaned hot water to a boiler.

Abstract: A method for recovering base oil from waste lubricating oil by separating base oil range constituents from a waste lubricating oil mixture, thereafter separating higher quality base oil constituents and lower quality base oil constituents from the base oil recovered from the waste lubricating oil mixture and thereafter treating the lower quality base oil constituents to produce marketable base oil. The total base oil produced from a waste lubricating oil mixture by this process is greater than the quantity producible by previous processes using only base oil separation from the waste lubricating oil mixture or processes which use only treatment of the base oil recovered from the waste lubricating oil mixture to produce the product base oil.

Abstract: The present application concerns a process for the removal of hydrocarbons from an aqueous stream, which process may include conducting a phenol-containing water stream into a separation column, separating the phenol-containing water in the column using heat to form an overhead portion and a bottoms portion, and collecting the overhead portion as well as the bottoms portion. Further, the process may include adding an eluent to an aqueous stream, thereby forming an aqueous mixture, subsequently conducting the aqueous mixture into a separation vessel, wherein it is allowed to settle into two phases, which form a hydrocarbon stream and a phenol-containing water stream, subsequently collecting the hydrocarbon stream, and conducting the phenol-containing water stream to the separation column for further separation.

Abstract: A process is disclosed for recovering product from catalytically converted product streams. An integrated debutanizer column provides an LPG stream, a light naphtha stream and a heavy naphtha stream. The integrated debutanizer column may comprise a dividing wall column. The light naphtha stream may be used as an absorbent for a primary absorber column which provides advantageous operation.

Abstract: Device for desalinating sea water comprising a unit (10) for spraying sea water in the form of droplets, a unit (20) for vaporizing the droplets into steam, a unit (30) for separating steam from salt particles, and a unit (40) for condensing steam into fresh water. The spraying unit comprises a sea water entry (12), an ambient-temperature dry air entry (14), and a device for generating acoustic waves at a frequency greater than 1 MHz focused by means of nozzles (17) receiving the sea water coming from the sea water entry so as to obtain microdroplets having a diameter comprised between about 2.5 microns and about 5 microns.

Abstract: The present disclosure relates to processes and systems for purifying technical grade trichlorosilane and/or technical grade silicon tetrachloride into electronic grade trichlorosilane and/or electronic grade silicon tetrachloride.

Abstract: A system and method for separating a fluid mixture is provided which employ vacuum distillation apparatus, and optionally, gas-handling apparatus operable to introduce a gas into the liquid mixture prior to being dispersed within the vacuum distillation apparatus. The liquid mixture is dispersed within the vacuum distillation apparatus as micro-sized droplets. When used, the gas that has been introduced into the liquid mixture is rapidly liberated from the micro-sized droplets thereby causing the droplets to break into still smaller droplets thereby maximizing the vaporization of the more volatile components in the liquid mixture.

Abstract: The present invention is directed to an enhanced process for separating dissolved and suspended solids from valuable or harmful liquids and more particularly to improving the operational aspects and separation efficiency of treating certain water miscible fluids including those used for oil and gas processing such as glycols, as well as automobile and aircraft fluids, that have become contaminated with dissolved and/or suspended solid matter.

Abstract: Methods for continuously preparing cyclohexanone from phenol make use of a catalyst having at least one catalytically active metal selected from platinum and palladium. The process includes enriching phenol in a distillation fraction as compared to a subsequent fraction, wherein the subsequent fraction includes phenol and side-products having a higher boiling point than phenol. Distillation is carried out in a vacuum distillation column equipped with trays in the lower part of the column. In an upper part of the column, i.e., in the part above the feed inlet, packing material is present instead of trays in at least part thereof. The packing material has a comparable or improved separating efficiency, and provides a reduction of the pressure drop by at least 30%, preferably more than 50%, as compared to the case with trays in the upper part, under otherwise similar distillation conditions.

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

Abstract: A method of dehydrating tolylenediamine which includes subjecting tolylenediamine having a water content of 5-40 wt. % to first-stage distillation at a vacuum of 13-101.3 kPa and subjecting the bottoms from the first-stage distillation to second-stage distillation at a vacuum lower than 13kPa.

Abstract: A process for removing trioxane from a use stream I of formaldehyde, trioxane and water, by a) providing a use stream I which comprises formaldehyde as the main component and trioxane and water as the secondary components, b) feeding the use stream I, a recycle stream V and a recycle stream VII which comprises formaldehyde as the main component and water and trioxane as the secondary components into a first distillation stage and distilling to obtain a stream II a steam III and formaldehyde as the and a steam X c) distilling the stream III, in a second distillation stage the pressure in the second distillation stage being from 0.

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. The apparatus for separating a liquid mixture of two or more solvents comprises components a stripping column, at least one over-head compressor and, thereafter, at least one selectively permeable membrane wherein the membrane separates the components of the vapor based on the different sorption and diffusion characteristics.

Abstract: A method and a system to produce a distillate stream from an aqueous stream containing at least one dissolved solid by a thermal distillation process using at least one of a heated aqueous stream from a turbine system intercooler and a stack heater as a heat source.

Abstract: Processes for the continuous fractional distillation of a mixture containing morpholine (MO), monoaminodiglycol (ADG), ammonia and water from a reaction of diethylene glycol (DEG) with ammonia, the process including: (i) separating off ammonia from the mixture at a top of a first distillation column K10; (ii) feeding a bottom fraction from K10 to a second distillation column K20, in which water and an organic product are separated off at the top at a temperature at the top in the range from 45 to 198° C. and a pressure in the range from 0.

Abstract: The present invention relates to a process and a system for producing alcohol by distillation with energy optimization using split-feed technology. The process of the present invention comprises the steps of: a) splitting a stream of wine to feed two depuration columns , the depuration column generating a stream of phlegma and the depuration column generating a stream of phlegma and a stream of vinasse; b) feeding the stream of phlegma into at least one rectification column generating a top flow and a stream of hydrated alcohol; c) effecting the heat exchange between the top flow from at least one rectification column and the stream of vinasse from the depuration column in at least one heat exchanger; and d) feeding the stream of phlegma into a rectification column generating a stream of hydrated alcohol. The present invention further relates to hydrated alcohol produced by the process described above and to a process for producing anhydrous alcohol.

Abstract: The present disclosure relates to processes and systems for purifying technical grade trichlorosilane and/or technical grade silicon tetrachloride into electronic grade trichlorosilane and/or electronic grade silicon tetrachloride.

Abstract: Processes for the continuous fractional distillation of a mixture comprising morpholine (MO), monoaminodiglycol (ADG), ammonia and water from a reaction of diethylene glycol (DEG) with ammonia, the process comprising: (i) separating off ammonia from the mixture at a top of a first distillation column K10; (ii) feeding a bottom fraction from the first distillation column to a second distillation column K20, wherein water and an organic product are separated off at a top of the second distillation column at a top temperature of 45 to 198° C. and a pressure in the range from 0.1 to 15 bar; (iii) feeding a bottom fraction from the second distillation column to a third distillation column K30, wherein morpholine and an organic product having a boiling point of <140° C. (1.013 bar) are separated off at a point selected from a top and a side offtake of the third distillation column, and monoaminodiglycol and an organic product having a boiling point of >190° C. (1.

Abstract: Process for the continuous fractional distillation of mixtures including morpholine (MO), monoaminodiglycol (ADG), ammonia and water obtained by reaction of diethylene glycol (DEG) with ammonia, which includes separating off ammonia at the top of a first distillation column K10, feeding the bottoms from K10 to a second distillation column K20 in which water and organic products are separated off at the top at a temperature at the top in the range from 45 to 198° C. and a pressure in the range from 0.1 to 15 bar, feeding the bottoms from K20 to a third distillation column K30 in which MO and organic products having a boiling point of <140° C. (1.013 bar) are separated off at the top or at a side offtake and ADG and organic products having a boiling point of >190° C. (1.013 bar) are separated off at the bottom, feeding the MO including stream which is separated off at the top or at a side offtake of the column K30 to a fourth column K40 in which organic products having a boiling point of ?128° C. (1.

Abstract: The invention relates to a method and a device for the purification of an aqueous solution of an organic acid having a boiling point at atmospheric pressure of less than 450° C., which further has approximately 275 g carboxylate ions/l or less, preferably 250 g carboxylate ions/l or less, and preferably less than 1% by weight ionic impurities, calculated on the basis of the total solution. In particular, the invention relates to a method and a device for the continuous purification and concentration, on an industrial scale, of an aqueous solution of an organic acid having a boiling point at atmospheric pressure of less than 450° C. According to the method, this solution is subjected to two or more distillation steps, the first distillation step being carried out at a temperature of from 80° to 150° C. and a pressure of from 50 to 250 mbar, and the second distillation step being carried out at a temperature of from 80° to 200° C. and a pressure of from 0.01 to 50 mbar.

Abstract: An energy-efficient extractive distillation process for producing anhydrous ethanol from aqueous/ethanol feeds containing any range of ethanol employs an extractive distillation column (EDC) that operates under no or greatly reduced liquid reflux conditions. The EDC can be incorporated into an integrated process for producing anhydrous ethanol used for gasoline blending from fermentation broth. By using a high-boiling extractive distillation solvent, no solvent, is entrained by the vapor phase to the EDC overhead stream, even under no liquid reflux conditions. The energy requirement and severity of the EDC can be further improved by limiting ethanol recovery in the EDC. In this partial ethanol recovery design, ethanol which remains in the aqueous stream from the EDC is recovered in a post-distillation column or the aqueous stream is recycled to a front-end pre-distillation column where the ethanol is readily recovered since the VLE curve for ethanol/water is extremely favorable for distillation.

Abstract: Processes for removing water from organic solvents, such as ethanol. The processes include distillation in two columns operated at sequentially higher pressure, followed by treatment of the overhead vapor by one or two membrane separation steps.

Abstract: Processes for removing water from organic solvents, such as ethanol. The processes include distillation in two columns operated at sequentially higher pressure, followed by treatment of the overhead vapor by one or two membrane separation steps.

Abstract: An apparatus and process for the separation of refrigerant mixtures is provided. The apparatus includes a first distillation column, a first condenser, and a first collection vessel. The apparatus also includes a sorter vessel that includes a sorter agent, wherein the sorter vessel is fluidly connected to the first distillation column.

Abstract: An energy-efficient extractive distillation process for producing anhydrous ethanol from aqueous/ethanol feeds containing any range of ethanol employs an extractive distillation column (EDC) that operates under no or greatly reduced liquid reflux conditions. The EDC can be incorporated into an integrated process for producing anhydrous ethanol used for gasoline blending from fermentation broth. By using a high-boiling extractive distillation solvent, no solvent is entrained by the vapor phase to the EDC overhead stream, even under no liquid reflux conditions. The energy requirement and severity of the EDC can be further improved by limiting ethanol recovery in the EDC. In this partial ethanol recovery design, ethanol which remains in the aqueous stream from the EDC is recovered in a post-distillation column or the aqueous stream is recycled to a front-end pre-distillation column where the ethanol is readily recovered since the VLE curve for ethanol/water is extremely favorable for distillation.

Abstract: Process for recovering cyclododecatriene (CDT) from a solution containing CDT and high boilers such as deactivated catalyst and polymers, which includes feeding the solution into a preheater and heating it, subsequently depressurizing it through a downstream pressure maintenance device and feeding the resulting two-phase mixture into a helical tube evaporator and there reducing the CDT content of the liquid phase by partial evaporation and discharging a gaseous product stream having an increased concentration of CDT.

Abstract: A method of recovering a liquid medium from a mixture containing the liquid medium, the method including: (a) blowing a first gas into the mixture containing the liquid medium to vaporize the liquid medium, in a first vaporizing means, thereby to form a second gas containing which is a mixture of the first gas and vaporized liquid medium; (b) continuously dropwise feeding the mixture containing the liquid medium into a second vaporizing means and counter-flowingly contacting the mixture containing the liquid medium, with the second gas to vaporize additional liquid medium to form a third gas which is a mixture of the second gas and additional vaporized liquid medium; and (c) feeding the third gas into a condensing means to condense the vaporized liquid medium into a liquid and separate the first gas, which is then blown into the first vaporizing means in step (a).

Abstract: A distillation apparatus of the present invention includes a distillation column group in which a plurality of distillation columns including a condenser and a reboiler is connected in the form of a cascade; a gas-feeding line which feeds gas from the distillation column to a latter distillation column; a gas line which introduces the gas from the distillation column to the condenser attached to the distillation column; a liquid-line which withdraws a condensed liquid from the condenser; a liquid-reflux line which introduces a part of the condensed liquid from the liquid-line to the distillation column; a liquid-return line which returns the remainder of the condensed liquid from the liquid-line to a former distillation column; a valve provided on the liquid-return line; and a bypass line which connects the liquid-return line and the gas line so as to flow an evaporated gas generated in the liquid-return line to the gas line.

Abstract: The present disclosure relates to processes and systems for purifying technical grade trichlorosilane and/or technical grade silicon tetrachloride into electronic grade trichlorosilane and/or electronic grade silicon tetrachloride.

Abstract: A method for concentrating effectively the heavy nitrogen isotope 15N to 50 atom % or more in which 14N15N and/or 15N2, which are molecules containing a heavy nitrogen isotope of 15N, are concentrated by distilling successively nitrogen N2 using plural distillation columns T1 to T4 each of which includes at least one condenser C1 to C4 and at least one reboiler R1 to R4 and is arranged in series, and a part of nitrogen in the distillation is drawn out to be subjected to isotope scrambling in an isotope scrambler S1, and nitrogen after the isotope scrambling is returned to the distillation to produce nitrogen N2 with a 15N concentration of 50 atom % or more.

Abstract: A process for separating trioxane from a feed stream I comprising formaldehyde, trioxane and water, in which a) a feed stream I comprising formaldehyde as main component and trioxane and water as secondary components is provided, b) the feed stream I, a recycle stream V and a recycle stream VII comprising formaldehyde as main component and water and trioxane as secondary components are fed into a first distillation stage and distilled at a pressure of from 0.1 to 2.5 bar to give a stream II comprising formaldehyde as main component and water as secondary component and a stream III comprising trioxane as main component and water and formaldehyde as secondary components and a stream X comprising water, trioxane and formaldehyde, c) the stream III is, if appropriate after removal of low boilers from the stream III in a low boiler removal stage, distilled in a second distillation stage at a pressure of from 0.2 to 17.5 bar, with the pressure in the second distillation stage being from 0.

Abstract: The invention relates to a process for preparing 1-butenic fractions having less than 2000 ppm of isobutene in relation to 1-butene from technical mixtures of C4 hydrocarbons I which contain at least 1-butene and 2000 ppmw to 8% by mass of isobutene based on the 1-butene, with or without n-butane, isobutane and/or 2-butenes.

Abstract: A process for removing trioxane from a use stream I of formaldehyde, trioxane and water, by a) providing a use stream I of formaldehyde as the main component and trioxane and water as the secondary components, b) mixing the use stream I with a recycle stream VII to obtain a feed stream Ia, c) distilling the use stream Ia in a first distillation stage to obtain a stream II of formaldehyde as the main component and water as the secondary component, and a stream III of trioxane as the main component and water and formaldehyde as the secondary components, d) distilling the stream III in a second distillation stage having a pressure higher than in the first distillation stage, to obtain a stream IV of trioxane and a stream V of trioxane as the main component and water and formaldehyde as the secondary components, e) distilling the stream V in a third distillation stage to obtain a stream VI of water and the recycle stream VII of trioxane as the main component and water and formaldehyde as the secondary components

Abstract: A water-soluble organic material condensation apparatus equipped with a distillation column for distilling an aqueous solution of a water-soluble organic material, wherein a vapor generated at the top of the distillation column or a condensed liquid from the vapor is introduced to a device other than the distillation column which has the function to separate water from the water-soluble organic material to thereby condense the water-soluble organic material through separating water and then the condensed water-soluble organic material is recycled to the distillation column. The device other than the distillation column is desirably a separating film such as a zeolite film. The apparatus is improved in the operation of the upper portion of the condensation section of the distillation column and allows energy savings during distillation.

Abstract: Process for distillatively separating a mixture containing a vinyl ether of the general formula (I) R1—O—CH?CH2??(I) and alcohol of the general formula (II) R2—OH??(II) in which R1 and R2 are each independently a saturated or unsaturated, aliphatic or cycloaliphatic radical having from 2 to 10 carbon atoms, and in which the alcohol (II) has a boiling point which is at least 1° C. higher, measured at or extrapolated to 0.1 MPa abs, than the vinyl ether (I), by a) passing the mixture into a first distillation column and withdrawing, as a top product, an azeotrope containing vinyl ether (I) and alcohol (II) and, as a bottom product, a stream enriched with the alcohol (II); b) passing the azeotrope containing vinyl ether (I) and alcohol (II) from the first distillation column into a second distillation column which is operated at a pressure which is from 0.

Abstract: Purified water for special purposes is produced using a falling-film multieffect evaporator. From the feed water, each effect produces a steam phase and a water phase. The steam phase is used for heating in the subsequent evaporating step, whereby the steam phase condenses to product water, and the water phase becomes feed water for the subsequent evaporation step. According to the invention, the product water may be wholly or partly recycled to the initial feed water, allowing process startup and sterilisation of the plant without conducting hot product water to the drain.

Abstract: A process for recovering crude 1,3-butadiene from a C4 fraction by extractive distillation using a selective solvent in a dividing wall column (TK) in which a dividing wall (T) is arranged in the longitudinal direction of the column to form a first subregion (A), a second subregion (B) and a lower common column region (C) and which is preceded by an extractive scrubbing column (K), wherein the operation of the dividing wall column (TK) is set by regulation of the energy input into the dividing wall column (TK) via a bottom vaporizer (V) and setting of the number of the theoretical plates in the lower common column region (C) so that a bottom stream (17) consisting of purified solvent is obtained from the dividing wall column (TK), is proposed.

Abstract: The invention relates to an energy efficient process for the distillative working-up of aqueous amine solutions that occur in the catalytic hydrogenation of nitroaromatic compounds. In this process, the amine is freed from water and also the water is obtained free from amine and low-boiling compounds and the concentrated low-boiling compounds are obtained.

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 for rectificatively separating an acrylic acid-containing liquid, by withdrawing an acrylic acid-rich stream from the rectification column above the feed point and polymerization-inhibiting the upper section of the rectification column by means of diacrylic acid.

Abstract: A process is described for the recovery of substantially pure ethyl acetate from a feedstock including ethyl acetate, ethanol and water. The process includes supplying the feedstock to a first distillation zone maintained under first distillation conditions effective for distilling from the feedstock a first distillate including ethyl acetate, ethanol, and less than about 10 mol % water. The first distillate is recovered from the first distillation zone and is supplied to a second distillation zone maintained under second distillation conditions, which include use of a higher pressure than that of the first distillation zone. The second distillation conditions are effective for distilling from the first distillate a second distillate including ethanol, water, and a minor proportion of ethyl acetate and yielding a substantially pure ethyl acetate bottom product, which is recovered. The second distillate is returned to the first distillation zone.

Abstract: The object of the present invention is to provide a method for concentrating effectively the heavy nitrogen isotope 15N to 50 atom % or more. In order to achieve the object, the present invention provides a method for concentrating a heavy nitrogen isotope 15N, in which 14N15N and/or 15N2, which are molecules containing a heavy nitrogen isotope of 15N, are concentrated by distilling successively nitrogen N2 using plural distillation columns T1 to T4 each of which comprises at least one condenser C1 to C4 and at least one reboiler R1 to R4 and is arranged in series, and a part of nitrogen in the distillation is drawn out to be subjected to isotope scrambling in an isotope scrambler S1, and nitrogen after the isotope scrambling is returned to the distillation to produce nitrogen N2 with a 15N concentration of 50 atom % or more.

Abstract: The invention relates to the field of separation by distillation of 6-aminocapronitrile (ACN) and hexamethylenediamine (HMD) from a mixture containing ACN, HMD, tetrahydrozaepine (THA), adiponitrile (ADN) and low boilers (LB). A method for producing a distillate stream comprising HMD is disclosed, which is suitable for the production of Nylon-6,6. The tails stream from the distillation of the mixture can be further distilled to produce a distillate containing ACN and THA, which is particularly suitable for use in the production of caprolactam and Nylon-6 from the caprolactam. Process conditions of the method of the invention disfavor the production of 2-cyanocyclopentylideneirnine (CPI).

Abstract: The present invention relates to a new process for obtaining fatty acids with improved color, odor and heat stability which is characterized in that: (a) in a first step the crude acids are fed to a rectification (“precut”) column in order to remove low boiling by-products being present in the starting material as a top fraction, and (b) in a second step the bottom fraction of the precut column is fed to a sidestream column in order to obtain the pure fatty acids as the side fraction, to remove low boiling by-products which have been formed in the course of the first distillation as a top fraction and to remove high boiling by-products, either being present from the starting material or formed during the first distillation, with the residue.

Abstract: The present invention provides a continuous process for recovering acetone from a waste stream from an acetone purification stage. The waste stream contains mesityl oxide and optionally acetone. The process for recovering acetone includes separating the waste stream in a separating device at least in one stream containing mesityl oxide and optionally a further stream containing acetone, then concentrating mesityl oxide in the mesityl oxide containing stream, and finally recycling the concentrated mesityl oxide stream to the separating device and bringing it into contact with a basic or acidic aqueous medium or with an acidic catalyst in the presence of water whereby mesityl oxide is at least partially hydrolyzed to acetone.