Abstract: Disclosed is a method of efficiently separating 1,3-butadiene and methylethylketone, which are compounds of interest, from byproducts or impurities in the dehydration products of 2,3-butanediol so as to recover the compounds of interest at high purity.

Abstract: A method and system for disposal of furfural wastewater, wherein raw crop material is transported into a hydrolysis reactor after crushed and mixed with acid to be hydrolyzed to form raw furfural liquid, and then said raw furfural liquid is transported into a distillation column to be distilled, during which furfural wastewater is discharged from said distillation column. Firstly said furfural wastewater is transported into a wastewater evaporation system to be heated it into wastewater vapor which is then transported back into said hydrolysis reactor to form recycle of said furfural wastewater. Wastewater vapor residues generated therein can be utilized directly to combust in boiler, mix with acid, or prepare end product acetate. The system for disposal of furfural wastewater comprises at least a wastewater evaporation system connecting with a heat resource which is one of steam, electricity, coal, oil, gas, plant straws or wastewater vapor residues.

Abstract: The invention provides systems and methods for the pre-concentration of a target molecule from feed solution comprising a low concentration of the target molecule.

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: 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: 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 process for obtaining process water by condensation of mist or by evaporation of water comprising salts or impurities and condensation of the evaporated water, and plants for carrying out the process and the use thereof for obtaining drinking water.

Abstract: The invention relates to a process for reducing the aldehyde concentration in a mixture comprising cyclohexanone and one or more aldehydes, said process comprising distilling said mixture in a distillation column in the presence of an alkaline compound, wherein in the bottom of the distillation column substantially no water is present.

Abstract: Processes are described which comprise: (a) providing a mixture comprising a cyclic formal and water, wherein the mixture has a cyclic formal concentration and a water concentration; (b) bringing the mixture into contact with an aqueously selective membrane; (c) creating a pressure differential across the membrane; and (d) obtaining a permeate having a higher water concentration and a lower cyclic formal concentration than the mixture, and a retentate having a lower water concentration and a higher cyclic formal concentration than the mixture.

Abstract: A method and system for disposal of furfural wastewater, wherein raw crop material is transported into a hydrolysis reactor after crushed and mixed with acid to be hydrolyzed to form raw furfural liquid, and then said raw furfural liquid is transported into a distillation column to be distilled, during which furfural wastewater is discharged from said distillation column. Firstly said furfural wastewater is transported into a wastewater evaporation system to be heated it into wastewater vapor which is then transported back into said hydrolysis reactor to form recycle of said furfural wastewater. Wastewater vapor residues generated therein can be utilized directly to combust in boiler, mix with acid, or prepare end product acetate. The system for disposal of furfural wastewater comprises at least a wastewater evaporation system connecting with a heat resource which is one of steam, electricity, coal, oil, gas, plant straws or wastewater vapor residues.

Abstract: A process for purifying an aqueous solution to obtain purified gaseous acrolein by introducing the aqueous solution into a distillation column equipped at its base with at least one boiler and at its top with at least one condenser, withdrawing a liquid mixture essentially containing water at the base of the distillation column, withdrawing a gas essentially containing acrolein and water at the top of the distillation column, cooling the gas mixture withdrawn at the top of the distillation column in the condenser, to a temperature which makes it possible to obtain, on the one hand, an aqueous condensate and, on the other hand, an acrolein-rich gas mixture, and withdrawing the acrolein-rich gas mixture.

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

Abstract: The invention relates to a process for separating close-boiling, homo- and heteroazeotropic mixtures by using ionic liquids. Due to the selectivity and unusual combination of properties of the ionic liquids the process is superior to conventional extractive rectification from the point of view of costs and energy.

Abstract: A formaldehyde-containing product is separated from a formalin solution containing formaldehyde, water, and methanol by distilling in the presence of a water entraining compound, especially methyl propionate or methyl methacrylate. The product contains substantially less water than in the solution and may be used, for example, in a further process which requires a source of formaldehyde containing a relatively low level of water, for example, the catalyzed reaction of methy propionate with formaldehyde and methanol to produce methyl methacrylate.

Abstract: The invention relates to a process for recovering and producing chemicals in a pulp production process where organic chemicals, such as formic acid and acetic acid, are used as cooking chemicals. The process of the invention is based on regeneration of cooking acids and formation of additional cooking acids and furfural by evaporating the cooking liquor and then separating acetic acid, formic acid, furfural and water. The separation is preferably carried out by distillation using the furfural formed in the process as a distilling aid in the distillation.

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: In a process for purification of ethylene oxide by distillation an aqueous mixture comprising ethylene oxide, formaldehyde and at least 5% by weight of water is introduced via a feed into a distillation apparatus comprising at least one distillation column, the mixture being introduced at a height above the bottom of at least 8 theoretical stages, the ethylene oxide is taken off at the top and in the bottom phase a mixture is obtained which contains less than 5% by weight of ethylene oxide.

Abstract: A process for recovering DCPD from a hydrocarbon feedstock comprising introducing the hydrocarbon feedstock to a first column, recovering an overhead stream from the first column comprising C9− hydrocarbons, recovering a bottom stream from the first column comprising C10+ hydrocarbons, feeding the bottom stream from the first column to a second column, recovering an overhead stream from the second column comprising DCPD, and recovering a bottom stream from the second column comprising fuel oil, wherein the two columns are sized and operated at defined conditions such as pressures, temperatures, reflux rates, and reboil rates.

Abstract: The invention consists of a cost-effective process and facilities for obtaining high quality drinking water and high-grade brine as a chemical raw material from raw water regardless of how much salt it contains. When combined with a thermal power-generation process, the plant also produces electric power with a fuel utilization of over 85%.

Abstract: A formaldehyde-containing product is separated from a formalin solution containing formaldehyde, water and methanol by distilling the solution in the presence of a water entraining compound, especially methyl propionate or methyl methacrylate. The product contains substantially less water than in the solution and may be used, for example, in a further process which requires a source of formaldehyde containing a relatively low level of water, for example, the catalyzed reaction of methyl propionate with formaldehyde and methanol to produce methyl methacrylate.

Abstract: A process for producing methylal that involves feeding a liquid containing methanol, formaldehyde and water to an uppermost reactor of at least four solid acid catalyst-filled reactors which are each externally connected to an intermediate portion of a distillation column; and forcibly circulating a liquid containing methanol, formaldehyde, water and produced methylal in a temperature range of 80° C. to 100° C.

Abstract: A process for the purification of raw acetone deriving from processes for the production of phenol acetone, impurity mainly due to cumene, water, aldehydes and methanol, the steps of:feeding the stream of raw acetone coming from the primary fractionation of a plant for the production of phenol and acetone to a first distillation column to which a solution of sodium hydroxide at 2% is also fed;sending the stream at the head of the first column, containing of acetone, water and cumene to a second column to which the extractive solvent triethyleneglycol is also fed;recovering substantially anhydrous acetone from the head of the second column;feeding the bottom product of the second column, containing triethyleneglycol, water, cumene and acetone to a third distillation column in which an azeotropic mixture of water and cumene is recovered from the head and anhydrous triethyleneglycol from the bottom;sending the azeotropic mixture of water and cumene to a decanter in which a water phase is separated, containing ac

Abstract: A purification process for cyclic formals, in which water is efficiently removed from a crude cyclic formal, namely, a mixture of a cyclic formal and water which is difficult to be separated from the mixture, thereby obtaining a cyclic formal of high purity which contains only a very small amount of water.The purification process for cyclic formals is characterized by the following two purification steps:(1) Supplying a mixture of a cyclic formal and water into a distillation tower at a supply position, and effecting distillation while supplying a hydrophilic solvent (A) having a boiling point from 180.degree. to 250.degree. C. at a position higher than the supply position of the mixture to take out a cyclic formal (X) containing 100 to 5000 ppm of water as a distillate, and(2) Distilling the cyclic formal (X) obtained in step (1) or treating it with a dehydrant to obtain a purified cyclic formal (Y) which contains less water than in the cyclic formal (X).

Abstract: A purification process for cyclic formals, in which water is efficiently removed from a crude cyclic formal, namely, a mixture of a cyclic formal and water which is difficult to be separated from the mixture, thereby obtaining a cyclic formal of high purity which contains only extremely small amounts of water and impurities.The purification process for cyclic formals is characterized by the steps of supplying a mixture of a cyclic formal and water into a distillation tower, effecting distillation while supplying a hydrophilic solver (A) having a boiling point from 180.degree. to 250.degree. C. and a purified cyclic formal (X) containing not more than 200 ppm of water into the distillation tower at positions higher than the supply position of the mixture and higher than the supply position of the hydrophilic solvent (A), respectively, and taking out a purified cyclic formal from the top of the tower as a distillate.

Abstract: A method for producing a dimerized aldehyde, which comprises subjecting a feed aldehyde to a condensation reaction and a dehydration reaction in the presence of a basic catalyst, wherein the feed aldehyde is the one having one or two hydrogen atoms at the .alpha.-position, an organic feed stream containing the feed aldehyde is supplied to a reactive distillation column, and the condensation reaction and the dehydration reaction are carried out simultaneously in the reactive distillation column.

Abstract: Vinyl formate containing formic acid, acetaldehyde and water following synthesis is separated from formic acid and water in a first distillation stage and from acetaldehyde in a second stage to give pure vinyl formate.

Abstract: An improved process for azeotropic distillation of chloral to anhydrous chloral containing as little as 0.1% water. An azeotropic mixture is used which contains chloral in at least a 1.4:1 ratio with the concentration (% of weight) of a azeotropic agent (preferably ethylene dichloride). The feed stream may contain other components, but will contain at least 60% chloral and less than 40% water. Preferably, the feed stream is substantially free of components other than choral and water. Water is removed from the overhead product of the azeotropic and EDC separation distillations periodically or continuously throughout the process. The azeotropic agent is preferably separated from the anhydrous chloral product. This separation may be performed in the azeotropic distillation column or in a separate distillation column.

Abstract: A purification process for cyclic formals, in which water is efficiently removed from a mixture of a cyclic formal and water which is difficult to be separated from the mixture, thereby obtaining a cyclic formal of high purity which contains only an extremely small amount of water.The purification process for cyclic formals is characterized by the steps of supplying a mixture of a cyclic formal and water into a distillation tower, effecting distillation while supplying n-pentane into the distillation tower and taking out a purified cyclic formal as a bottom liquid.

Abstract: A method of dehydrating a solvent originating from a hydrocarbon dewaxing operation, wherein a moist composite organic solvent, for example a moist MEK/toluene mixture is dehydrated in a first distillation zone, the resulting first distillate is contacted with water to form two phases one of which, rich in organic solvent, is returned as a reflux to the first distillation zone whereas the other phase rich in water is distilled in a second distillation zone, and the head product and one portion of the bottom product of the second distillation zone are returned to the zone of contact between the first distillate and water, the invention being applicable to the dewaxing of lubricating oils.

Abstract: An improved method for dehydration and concentration of an aqueous solution containing an organic compound is disclosed. The solution is evaporated to produce a gaseous mixture comprising an organic compound vapor and a water vapor. The water vapor is selectively removed from the gaseous mixture by permeation through an aromatic polyimide gas separation membrane while the gaseous mixture being kept in contact with a surface on one side of the gas separation membrane at a temperature of 70.degree. C. or higher to obtain a gaseous mixture comprising the organic compound vapor and a reduced amount of a water vapor.

Abstract: A dilute solution of methyl ethyl ketone is concentrated by pervaporation through a fluorinated ion exchange membrane which has been exchanged with a quaternary ammonium cation.

Abstract: The invention relates to a process for obtaining trioxane from aqueous solutions by high-pressure extraction using an extracting agent which is in the form either of a gas in the supercritical state or of a liquid gas. An intermediate separation is advantageous, especially in the former case.The trioxane can be obtained in high concentration and with a saving of energy by the process according to the invention.

Abstract: Disclosed is a method for separating and concentrating an organic component having a lower boiling point than water from an aqueous solution containing the organic component which comprises the steps of (1) bringing an aqueous solution containing an organic component having a lower boiling point than water into contact with one surface of a hydrophobic porous membrane, continuously or intermittently evacuating the side of the porous membrane opposite to the aqueous solution to obtain a concentrated vapor of the organic component, and liquefying the vapor; and (2) bringing the resulting concentrated aqueous solution into contact with one surface of a hydrophobic nonporous membrane, evacuating the side of the non-porous membrane opposite to the concentrated aqueous solution to obtain a further concentrated vapor of the organic component, and liquefying the vapor.

Abstract: The preparation of aldehydes by the reaction of olefins with carbon monoxide and hydrogen in the presence of water and water-soluble rhodium/phosphine complex compounds as catalysts. The method comprises first cooling the organic part of the liquid phase to 70.degree. to 90.degree. C. in a stripping column by treatment with the carbon monoxide/hydrogen mixture fed into the reactor, further cooling the organic part to 20.degree. to 40.degree. C. by heat exchange with the feed olefin, subsequently relieving the pressure with the consequent formation of waste gas and aqueous and organic phases, and finally separating the phases so as to recover substantially all of the catalyst and the heat of reaction.

Abstract: Distillation of the heavy waste stream from the manufacture of phenol via the cumene process provides an overhead stream containing phenol, acetophenone and 2-phenyl propionaldehyde. Extraction of the overhead stream with aqueous caustic removes the phenol and subsequent distillation of the remaining two components in the presence of a catalytic amount of caustic provides a substantially pure acetophenone distillate.

Abstract: A process for recovering trioxane from an aqueous solution containing trioxane and triethylamine by the distillation separation process which comprises feeding an aqueous solution containing trioxane and triethylamine to the first distillation column, distilling out triethylamine, trioxane and water from the column top of the first distillation column, withdrawing an aqueous solution containing the major part of the trioxane present in the fed solution from the column bottom of the first distillation column, feeding the withdrawn solution to the second distillation column and taking out the substantially whole quantity of the trioxane fed to the second distillation column from the column top of the second distillation column.

Abstract: A method of recovering or extracting chemicals, such as furfural, formic acid, acetic acid and other organic compounds from acidic hydrolysates of plants or vegetable matter, especially spent sulfite liquors after conversion of the pentosans into pentoses and then into furfural by heating the hydrolysate in an acidic environment. The conversion of the pentosans pentoses into furfural, preferably with acidulation, is accomplished in a counterflow or countercurrent flow heat exchanger and a reactor, preferably a tubular reactor. The hydrolysate which has additionally been heated and converted in the reactor is used as a heating medium or heat carrier for heating up the hydrolysate which is converted in the counterflow heat exchanger, whereupon there is recovered as the distillate furfural in conjunction with the formic acid, acetic acid and the like.

Abstract: Process and apparatus for extracting an organic liquid from an organic liquid solute/solvent mixture. The mixture is contacted with a fluid extractant which is at a temperature and pressure to render the extractant a solvent for the solute but not for the solvent. The resulting fluid extract of the solute is then depressurized to give a still feed which is distilled to form still overhead vapors and liquid still bottoms. The enthalpy required to effect this distillation is provided by compressing the still overhead vapors to heat them and indirectly to heat the still feed. The process is particularly suitable for separating mixtures which form azeotropes, e.g., oxygenated hydrocarbon/water mixtures. The energy required in this process is much less than that required to separate such mixtures by conventional distillation techniques.

Abstract: A process for dehydrating an essentially one-phase wet solvent stream obtained in a solvent dewaxing-solvent deoiling process, which solvent stream contains at least 60% toluene with the balance being water and methyl ethyl ketone (hereinafter MEK), is dehydrated by (a) fractionally distilling to produce a bottom fraction of anhydrous MEK-toluene solvent and an overhead fraction containing all the water originally present in the wet solvent stream; (b) condensing and separating said overhead fraction into a toluene-containing, water-lean phase, which is used as reflux in step (a), and a toluene-free, MEK-containing, water-rich phase; (c) extracting into a hydrocarbon stream some MEK from said water-rich phase and from the condensed azeotropic mixture recycled from step (g) hereinafter; (d) recovering from step (c) a second water-rich stream, which water-rich stream contains the MEK not extracted into said hydrocarbon stream; (e) azeotropically distilling said second water-rich stream so as to obtain water as

Abstract: Separation by distillation and formation of immiscible liquid phases of nearly equal densities which comprises distilling a mixture containing the same in the presence of an added liquid of substantially different density, preferentially soluble in a recycle to the distillation zone and having a volatility under conditions of distillation such that it will vaporize preferentially to a liquid desired to be retained in the distillation zone to be removed as bottoms therefrom, e.g., toluene added to produce gravity separation of a heavy water-rich phase and a light phase containing phenol, cyclohexanone and cyclohexylbenzene and the added toluene which is used as reflux to the drying column in the overall process in which cyclohexanone and phenol are produced from cyclohexylbenzene.