Abstract: The invention relates to a process for the separation of a ketoxime or aldoxime from a ketoxime- or aldoxime-containing amide mixture in which the ketoxime or aldoxime is separated from the amide mixture by distillation. This has proved to be a very simple and direct method for separating the ketoxime and/or aldoxime from the desired amide.

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: A process is disclosed for the purification, by distillation, of trimethylolpropane originating from the hydrogenation of 2,2-dimethylolbutanal, said process including the following steps: (a) reaction of n-butyraldehyde with formaldehyde in the presence of catalytic amounts of a tertiary amine, and hydrogenation of the resulting mixture to give a mixture containing trimethylolpropane; (b) separation of water, methanol, trialkylamine and/or trialkylammonium formate by distillation; (c) heating of the residue obtained in (b) under reduced pressure to a temperature at which TMP is volatile and compounds boiling above TMP are cleaved, in order to separate off, by distillation, TMP and compounds more volatile than TMP; (d) distillation of the distillate obtained in (c) in order to separate off the more volatile compounds and recover pure TMP; and (e) optional distillation of the TMP obtained in (d) in order to recover TMP with a low APHA color index.

Abstract: A process for the separation of diisobutylene from tertiary butyl alcohol utilizing pressure swing azeotropic distillation to achieve the desired separation. The pressure swing azeotropic distillation takes advantage of the fact that different azeotropes are formed at different pressures. Isobutylene in C4 streams is oligomerized in the presence of tertiary butyl alcohol to produce the diisobutylene. Tertiary butyl alcohol is present in the dimerization because it improves the selectivity to the dimer (diisobutylene) by suppressing further reaction to the trimer or higher. The diisobutylene is separated from the tertiary butyl alcohol utilizing two distillation columns. The first distillation is operated at a higher pressure than the second such that the minimum boiling azeotropes of tertiary butyl alcohol and diisobutylene have different concentrations of tertiary butyl alcohol. Diisobutylene is removed as bottoms from the first distillation column and unreacted C4's are removed as overheads at 60-130 psig .

Abstract: This invention relates to a continuous process and an apparatus (1) for removing dissolved and undissolved solids and/or high boiling point liquid contaminants from a mixture of miscible liquids (9). A recycle liquor stream (6) is fed at high velocity through a heat exchanger having a single flow path (12) and the heat added by the heat exchanger is sufficient to vaporize the feed stream (2) when the recycle liquor and feed stream are mixed upon delivery to the separation vessel (3).

Abstract: The invention relates to azeotropic and azeotrope-like mixtures of 1,1,1,3,3-pentafluorobutane (HFC-365) and hydrogen fluoride and a process for separating the azeotrope-like mixtures. The compositions of the invention are useful as an intermediate in the production of HFC-365. The latter is useful as a nontoxic, zero ozone depleting fluorocarbon useful as a solvent, blowing agent, refrigerant, cleaning agent and aerosol to propellant.

Abstract: A method to purify N,N-dimethylacetamide (DMAc) from an aqueous solution containing acetic acid as a contaminant. Two fractional distillation columns are arranged in a series. The solution containing the contaminant is provided to the first column with a temperature profile to result in acetic acid partitioning into the overhead water. The material remaining in the bottom portion of the first column is recycled to the first column and also provided into a second column, whereby DMAc free of acetic acid contamination is recovered, and remaining DMAc and acetic acid are returned to the first column for further separation. The method uses standard fractional distillation procedures and equipment, thus eliminating the need for more complex extractions and/or chromatographic separations.

Abstract: The present invention relates to a process for separating the water from an aqueous lactam solution. It applies more particularly to a mixture resulting from the reaction between an aminonitrile and water (this reaction also being called cyclizing hydrolysis). The subject of the invention is a process for separating the water from an aqueous lactam solution, which process is economical both from the standpoint of the investment necessary for its implementation and from the standpoint of the operating cost.

Abstract: A process for the recovery of substantially pure alkyl alkanoate, such as ethyl acetate, from an impure feedstock. The impure feedstock is contacted with a selective hydrogenation catalyst in the presence of hydrogen in a selective hydrogenation zone maintained under selective hydrogenation conditions effective for selective hydrogenation of impurities containing reactive carbonyl groups thereby to hydrogenate the impurities to the corresponding alcohols. After recovery from the selective hydrogenation zone of a selectively hydrogenated reaction product mixture including the alkyl alkanoate and the corresponding alcohols, this is distilled in one or more distillation zones so as to produce substantially pure alkyl alkanoate therefrom which is recovered.

Abstract: A distillation apparatus includes a column body; a partition for dividing the interior of the column body; a first distillation section composed of an enriching section and an exhaust section; a second distillation section composed of an enriching section formed above an upper end of the first distillation section, and an exhaust section located adjacent to the enriching section of the first distillation section; a third distillation section composed of an enriching section located adjacent to the exhaust section of the first distillation section, and an exhaust section formed below a lower end of the first distillation section; a condenser; a negative pressure generation system for generating a negative pressure to thereby withdraw vent gas; a gas cooler for cooling the vent gas; a first discharge system disposed at the side of the column body and adapted to discharge liquid rich in a medium-boiling-point component formed from a high-melting-point material; and a second discharge system disposed at the botto

Abstract: Methods of recovering free fatty acids having a low ester content from alkanol-containing solutions and oil mixtures containing tocopherols are disclosed which involve atmospheric or vacuum stripping at low temperatures. The recovered fatty acids have a high acid value, and have high commercial value in the production of high quality (high acid value) products, e.g., dimerized fatty acids, useful in polyamide resins.

Abstract: A method for isolating 32 from a crude mixture containing HCl and an azeotropic mixture of 32 and HF is provided without the need to isolate any HF azeotrope.

Abstract: A process for the distillative recovery of high purity monoethylene glycol from the hydrolysis, product of ethylene oxide by pressure dewatering, preferably in a battery, vacuum dewatering and subsequent purifying distillation, wherein during the vacuum dewatering an aqueous stream is withdrawn which contains-monoethylene glycol in a concentration below 1% by weight, preferably below 0.1% by weight, medium boilers and low boilers. The withdrawn aqueous stream is, optionally after further workup, removed from the system.

Abstract: A process for the work up of a reaction mixture obtained from the preparation of diaryl carbonate by direct carbonylation of aromatic hydroxy compounds is disclosed. The process entails obtaining a reaction mixture that contains diaryl carbonate, aromatic hydroxy compound, water, base and quaternary salt, separating the mixture in a distillation apparatus having only one theoretical separation stage into a liquid phase and a gas phase and recycling the liquid phase without further work up to the reaction step of the direct carbonylation.

Abstract: A process for the preparation of propylene oxide in the presence of methanol, in which propylene oxide is separated from a mixture comprising propylene oxide and methanol, and the resultant mixture comprising methanol is worked up, which comprises separating methanol from a mixture comprising methanol and methyl formate during the work-up.

Abstract: Process for the recovery of a purified adiponitrile (ADN) from a mixture of adiponitrile, aminocapronitrile and hexamethylenediamine, utilizing two sequential distillations: (1) a first distillation in which the mixture is distilled in a distillation column at a head pressure that causes at least 7% of the ADN to go into the distillate, along with bishexamethylenetriamine (BHMT) and 2-cyanocyclopentylideneimine (CPI), and (2) a second distillation in which the distillate from the first distillation is distilled in a second distillation column at a head pressure sufficient to cause minimum-temperature azeotropy between ADN and BHMT, thereby allowing the majority of the BHMT and CPI to be removed from the second distillation as distillate, and ADN, substantially free of both BHMT and CPI, to be removed as bottoms.

Abstract: The invention disclosed herein generally relates to a system and a method for supplying a carbon dioxide fluid feed to a plurality of applications. The method of the invention comprises the steps of directing a fluid feed, that includes a carbon dioxide component, from a carbon dioxide purifying means to a plurality of applications including at least two distinct applications, whereby contaminants are combined with the fluid at said applications, thereby forming an effluent that includes at least a portion of the carbon dioxide component and at least a portion of said contaminants; directing said effluent from at least one of the applications to said carbon dioxide purifying means; and purifying the carbon dioxide of the effluent at the carbon dioxide purifying means, thereby producing the carbon dioxide component of the fluid feed. The system of the invention is an apparatus for conducting the method of the invention.

Abstract: Ammonia is recovered from waste water containing NH3, at least one acid gas (CO2, H2S) and inert gases. Firstly, the waste water is passed through a pretreatment column and then, at least in part, into a total stripping column. The top product from the total stripping column is cooled in a condenser, and an aqueous NH3-containing condensate coming from the condenser is fed to an NH3 stripping column. The top product from the NH3 stripping column is brought into direct contact with circulating aqueous NH3-containing condensate in a wash column, and NH3 is recovered from the top product from the wash column. Some of the bottom product from the wash column is fed back into the NH3 stripping column. The temperature in the bottom region of the pretreatment column is set to from less than 30 to 200° C., a sub-stream of the waste water is introduced into the upper region of the pretreatment column, and a second sub-stream of the waste water is fed into the pretreatment column below the first sub-stream.

Abstract: The invention relates to a process of separation of mixtures containing HFC-365mfc/HF azeotropic compositions by two distillations at different pressures, as well as to a process of synthesis of HFC-365mfc which integrates this process of separation and a recycling of certain fractions towards the hydrofluorination step.

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: A process for the distillative recovery of high purity monoethylene glycol from the hydrolysis product of ethylene oxide by pressure dewatering, vacuum dewatering and subsequent purifying distillation, which includes the pressure dewatering columns or at least the first pressure dewatering column of the battery (2, 3, 4) having a stripping section with at least one separating stage, preferably with from 2 to 10 separating stages, particularly preferably with from 3 to 6 stages, and a portion of the overhead stream of the pressure dewatering column(s) (2, 3, 4) having a stripping section being removed from the system.

Abstract: A process for recovering processing liquids such as gas-treating liquids wherein a feed mixture containing the processing liquid, water, and optionally additional components that are more volatile than the processing liquid and components that are less volatile than the processing liquid, is initially heated in a first heating zone to a temperature sufficient to volatilize at least some of the water and a portion of the processing liquid without decomposing the processing liquid to produce a vapor stream containing volatilized water and processing liquid and a residuum containing the bulk of the processing liquid and less volatile component, the vapor stream being separated from the residuum and treated to produce recycle streams of water, purified processing liquid, and low and high boiling liquid fractions recovered from the purified processing liquid.

Abstract: A process for the purification of difluoromethane comprising: (a) subjecting a mixture comprising at least difluoromethane (HFC-32) and dichlorodifluoromethane (CFC-12) to a first distillation step in which a majority of either CFC-12 or HFC-32 is concentrated in a first distillate and a majority of the other component is concentrated in a first bottoms; and (b) subjecting the first distillate in step (a) to at least one additional second distillation step conducted at a different pressure in which a majority of the component concentrated in said first distillate is concentrated in a second bottoms and in which the other component is concentrated in a second distillate; and (c) recovering purified HFC-32 from one of said first or second bottoms.

Abstract: The invention relates to a circulation evaporator for separating mixtures consisting of more volatile and less volatile components, which comprises a discharge container that consists of at least a chamber for the feed and of a chamber for the outflow. The invention further relates to a process for the separation by distillation of a mixture consisting of more volatile and less volatile components by employing the circulation evaporator.

Abstract: Cyclic esters of hydroxy organic acids can be produced and recovered via azeotropic distillation. In certain embodiments cyclic esters, such as glycolide and lactide, can be produced from a fermentation broth or other feed stream that comprises a hydroxy organic acid, an ammonium salt of a hydroxy organic acid, an amide of a hydroxy organic acid, or an ester of a hydroxy organic acid using azeotropic distillation. The hydroxy organic acid of the feed stream or the hydroxy organic acid derived from the feed stream by decomposition is reacted to produce the cyclic ester. In other embodiments a crude composition of a cyclic ester of an organic ester can be purified using azeotropic distillation.

Abstract: A process for the recovery and purification of cyclobutanone from a crude product mixture obtained from an oxidation product mixture resulting from the oxidation of cyclobutanol to cyclobutanone in the presence of water. The process provides for the recovery of cyclobutanone in a purity of at least 90 weight percent by a combination of distillation steps.

Abstract: The subject-matter of the present invention is process for the purification of a mixture of aromatic polyamines obtained by hydrogenation of the corresponding aromatic polynitro compounds, said mixture comprising the various isomers of the said amines as well as reaction by-products, comprising the steps of carrying out a distillation of the mixture in a distillation column, wherein a first stream, corresponding to a fraction or to all of the stream recovered at the bottom of the distillation column, is separated and is used in a chemical reaction and a second stream is separated corresponding(i) to a stream drawn off from the side in the gas phase, in the lower third of the said column, this stream representing at most 20% or more than 80% of the total volume (first and second stream); or (ii) to a fraction of the first stream, this fraction representing 2 to 50% of the volume of the first stream, in order to treat it subsequently.

Abstract: There is provided a process for producing Guerbet alcohols not containing any heavy metals or soaps, wherein primary and/or secondary alcohols having 2 to 30 carbon atoms are condensed at elevated temperature in the presence of alkaline catalysts and/or heavy metal catalysts while eliminating the reaction water, and the reaction product is immediately separated by distillation without any additional purification.

Abstract: A process for the continuous recovery of (meth)acrylic acid from a liquid starting mixture containing (meth)acrylic acid, a high-boiling organic solvent and low boilers, medium boilers and high boilers is proposed, the mixture being separated into a first part-stream (a), which, in addition to (meth)acrylic acid, contains the low boilers and a part each of the medium boilers and high boilers, and a second part-stream (b), which contains the predominant part of the (meth)acrylic acid and is completely or virtually completely free of low boilers, and the (meth)acrylic acid being recovered from the part-stream (b).

Abstract: In a process for the preparation of (meth)acrylic acid from a mixture which contains (meth)acrylic acid and a solvent having a boiling point above the boiling point of (meth)acrylic acid by distillation of the mixture in a column which is connected to an evaporator and has a stripping section and a rectifying section, between which the mixture is fed in, and a side take-off for the (meth)acrylic acid, a polymeization inhibitor is fed into the column in the region of the top of the column and in the region of the side take-off, that amount of polymerization inhibitor which is introduced in the region of the top of the column being smaller than the amount introduced in the region of the side take-off.

Abstract: This invention concerns a process to provide high purity akylene carbonate though use of multiple distillations wherein the unused fractions are recycled to the reactor.

Abstract: A process for refining difluoromethane by removing hydrogen fluoride, which is contained in difluoromethane difficult to remove. The process involves distilling a mixture of difluoromethane with hydrogen fluoride where the mixture is in contact with sulfuric acid. The hydrogen fluoride remains in the liquid phase and the difluoromethane goes into the vapor phase.

Abstract: A process for the continuous recovery of (meth)acrylic acid from a liquid starting mixture containing (meth)acrylic acid, a high-boiling organic solvent and low boilers, medium boils and high boils is proposed, the mixture being separated into a first part-stream (a), which, in addition to (meth)acrylic acid, contains the low boilers and a part each of the medium boilers and high boilers, and a second part-stream (b). which contains the predominant part of the (meth)acrylic acid and is completely or virtually completely free of low boilers, and the (meth)acrylic acid being recovered from the part-stream (b).

Abstract: A method for the purification of crude acetonitrile comprising distilling the crude acetonitrile in a first fractional distillation column at below atmospheric pressure, withdrawing a first side draw fraction comprising acetonitrile, distilling the first side draw fraction in a second fractional distillation column at super atmospheric pressure, and withdrawing from the second distillation a second side draw fraction comprising purified acetonitrile.

Abstract: A distillation apparatus includes a column body; a partition for dividing the interior of the column body; a first distillation section composed of an enriching section and an exhaust section; a second distillation section composed of an enriching section formed above an upper end of the first distillation section, and an exhaust section located adjacent to the enriching section of the first distillation section; a third distillation section composed of an enriching section located adjacent to the exhaust section of the first distillation section, and an exhaust section formed below a lower end of the first distillation section; a condenser; a negative pressure generation system for generating a negative pressure to thereby withdraw vent gas; a gas cooler for cooling the vent gas; a first discharge system disposed at the side of the column body and adapted to discharge liquid rich in a medium-boiling-point component formed from a high-melting-point material; and a second discharge system disposed at the botto

Abstract: A process for distillative separation of pure (meth)acrylic acid from mixtures which include comprise (meth)acrylic acid and dimers and oligomers of (meth)acrylic acid and are essentially free from aldehydes and from components whose boiling point is lower than that of (meth)acrylic acid, using a distillation apparatus which has a thin-film evaporator, a condenser and a connection which contains a baffle device and links the thin-film evaporator and the condenser.

Abstract: The present invention is directed to an apparatus and method for the distillation of a readily polymerizable vinyl aromatic compound employing a polymerization inhibitor. The vinyl aromatic compound is subjected to distillation in at least one fractionation column having at least one reboiler for maintaining the bottoms of said column at a proper temperature. The reboiler includes a heating section and a vapor phase section. The bottoms fraction from the fractionation column is cycled to the reboiler and subjected to heat to vaporize at least a portion of the bottoms fraction to form a vapor phase in the vapor section, A slip stream of the bottoms fraction is introduced to the vapor phase section of the reboiler. The slipstream contains polymerization inhibitor that had been added to the process at the fractionation column. The invention reduces fouling at the reboilers. The slipstream is optionally introduced to the reboiler using one or more spray nozzles.

Abstract: A method for preparing an organosilane functionalized in the 3 position includes reacting an allyl compound (H2C═CH—CH2X) with a silane (R2R3R4SiH) in a reaction column under a pressure between 1 bar and 25 bar, in the presence of a heterogeneous platinum catalyst. The silane reactant is present in the reaction column, and introduced into the reaction column, in a stoichiometric excess with respect to the allyl compound. The reaction column preferably includes a reaction zone, a first separation zone located above the reaction zone, and a second separation zone located below the reaction zone, wherein a first product exits the reaction zone and enters the first separation zone, and a second product exits the reaction zone and enters the second separation zone. Distillation occurs simultaneously with the reaction in the reaction chamber.

Abstract: The invention relates to a process for the separation of a ketoxime or aldoxime from a ketoxime- or aldoxime-containing amide mixture in which the ketoxime or aldoxime is separated from the amide mixture by means of distillation.

Abstract: A process for distillative separation of pure (meth)acrylic acid from mixtures which comprise (meth)acrylic acid and dimers and oligomers of (meth)acrylic acid and are essentially free from aldehydes and from components whose boiling point is lower than that of (meth)acrylic acid, using a distillation apparatus which has a thin-film evaporator, a condenser and a connection which contains a baffle device and links the thin-film evaporator and the condenser.

Abstract: An aqueous solution of free hydroxylamine is prepared by treating a hydroxylammonium salt with ammonia by the countercurrent method in a stripping column by a process in which hydroxylamine is liberated and at the same time the solution obtained is separated by distillation into an aqueous hydroxylamine solution and a salt fraction. The novel process can be carried out in a simple and gentle manner and on a large scale. The danger of decomposition is minimized owing to the low thermal load, the low concentration of hydroxylamine and the short residence time in the process.

Abstract: A process for the evaporation of an available warm or hot liquid under a vacuum by applying a pressure drop thereon initiating flash-down evaporation, and followed by further flash-down evaporation under an applied pressure gradient whereby the residual liquid is raised by the vapor produced to an elevation sufficient for subsequently discharging the residual liquid from vacuum without a pump; and by separating the vapor phase from the residual liquid phase before condensing the vapor produced into distilled liquid.

Abstract: In one embodiment, the present invention relates to a method of treating a solution containing hydroxylamine, involving subjecting the solution containing hydroxylamine to fractional distillation using a packed column thereby providing a first distillate; and subjecting the first distillate to flashover distillation thereby providing a second distillate containing a hydroxylamine solution. In another embodiment, the present invention relates to an ultrapure solution simply containing hydroxylamine, at least one stabilizer, and water.

Abstract: Disclosed is a process for the production and purification of dialkyl naphthalenedicarboxylate compounds wherein a crude naphthalenediacarboxylic acid is esterified with an alkanol such as methanol to produce a crude esterification product comprising dialkyl naphthalenedicarboxylate, starting materials and other compounds and the crude esterification product is purified by flash distillation to remove impurities which can cause fouling of conventional distillation equipment. A particularly useful diester is dimethyl 2,6-naphthalenedicarboxylate.

Abstract: A process for isolating trioxane from an aqueous mixture which includes trioxane, water and formaldehyde, including removing trioxane from the mixture by pervaporation, and subjecting the mixture enriched in trioxane (permeate) to rectification to give trioxane and an azeotropic mixture of trioxane, water and formaldehyde.

Abstract: Apparatus and process are disclosed for the distillation separation of styrene monomer from ethylbenzene utilizing a split feed to two distillation columns in conjunction with cascade reboiling utilizing thermal energy from the overhead of one column to supply heat to the second.

Abstract: This invention concerns a process to provide high purity alkylene carbonate though use of multiple distillations wherein the unused fractions are recycled to the reactor.

Abstract: A process for recovering hexamethylenediamine (I) from a mixture (II) including(I) hexamethylenediamine,(III) hexamethyleneimine,(IV) a compound selected from 2-aminomethylcyclopentylamine and 1,2-diaminocyclohexane,(V) an imine,(VI) adiponitrile and 6-aminocapronitrileincludes distilling(a) a mixture (II) to obtain(a1) a low boiling fraction (III),(a2) a medium boiling fraction (VII) (I), (IV) and (V), and(a3) a high boiling fraction (V) and (VI),(b) a mixture (VII) to obtain(b1) an overhead product (IV), and(b2) a mixture (VIII) (I) and (V) as bottom product, and(c) a mixture (VIII) to obtain(c1) (I) as overhead product, and(c2) a bottom product (V).

Abstract: Processes for the purification and color stabilization of crude maleic anhydride by distillation in a batch or continuous distillation column.

Abstract: The present invention teaches an efficient and easier to operate distillation system to separate mixtures containing three or more components into streams enriched in one of the components. In this invention, a liquid stream enriched in the least volatile component is withdrawn from the bottom of one distillation column while a vapor stream enriched in the most volatile component is withdrawn from the top of another distillation column. Of these two distillation columns, the pressure of the distillation column with the bottom liquid enriched in the least volatile component is higher; and this higher pressure distillation column transfers at least two vapor streams from different locations to either one or more other distillation columns within the distillation system. For a ternary mixture, both the vapor streams are transferred to the distillation column with the top vapor enriched in the most volatile component.