Abstract: Method of producing aromatic hydrocarbons including: supplying a raw material stream to a C6 separation column, supplying an upper discharge stream from the C6 separation column to a first gasoline hydrogenation unit, and supplying a lower discharge stream from the C6 separation column to a C7 separation column; supplying an upper discharge stream from the C7 separation column to a hydrodealkylation reaction unit and supplying a lower discharge stream from the C7 separation column to a C8 separation column; separating benzene from discharged streams from the first gasoline hydrogenation unit and the hydrodealkylation reaction unit; removing a lower discharge stream from the C8 separation column and supplying an upper discharge stream from the C8 separation column to a second extractive distillation column; and separating styrene from a lower discharge stream of the second extractive distillation column and separating xylene from an upper discharge stream of the second extractive distillation column.

Abstract: Techniques and systems for reducing fouling in a polymerization system are described. The polymerization system includes a reactor coupled to a recycle system. The recycle system includes at least one fouling-susceptible unit. The technique includes inducing polymerization of a reactant, for example, at least one olefin monomer reactant, with a catalyst in the reactor. The technique may further include circulating a fluidizing stream through the reactor and the at least one fouling-susceptible unit. The fluidizing stream may include entrained particles tending to foul the at least one fouling-susceptible unit. The technique can further include contacting the fluidizing stream with a catalyst poison at at least one location upstream of the at least one fouling-susceptible unit in the recycle system.

Abstract: The invention provides a process for refining bio-based propylene glycol, wherein impurities having boiling points close to that of propylene glycol are separated. In this process, C5-C20 oleophilic alcohol compounds, C5-C20 alkanes and/or C4-C20 oleophilic ketone compounds are subjected to azeotropism as an azeotropic solvent together with the bio-based propylene glycol to obtain an azeotrope containing propylene glycol. Then the azeotropic solvent in the azeotrope is separated to obtain a crude propylene glycol which is further purified to obtain propylene glycol.

Abstract: The present invention relates to a process for purifying a mixture comprising MEG, MEA, EDA and DETA, and low boilers having a boiling point not higher than PIP and high boilers having a boiling point not lower than AEEA, wherein the process comprises the following steps: a) separating a mixture comprising MEG, MEA, EDA and DETA, and low boilers having a boiling point not higher than PIP and high boilers having a boiling point not lower than AEEA, into (i) a mixture A comprising EDA and the low boilers having a boiling point not higher than PIP; and (ii) a mixture B comprising MEA; and (iii) a mixture C comprising MEG, DETA and the high boilers having a boiling point not lower than AEEA; b) separating mixture C from stage a) into (i) a mixture D comprising MEG; and (ii) a mixture E comprising MEG, DETA and the high boilers having a boiling point not lower than AEEA; c) separating mixture E from stage b) either into (i) a mixture F comprising MEG and DETA; and (ii) a mixture G comprising the high boi

Abstract: Provided herein are olefinic feedstocks derived from conjugated hydrocarbon terpenes (e.g., C10-C30 terpenes), methods for making the same, and methods for their use.

Abstract: In the solution polymerization of ethylene co and homopolymers the solution leaving the reactor is heated to separate polymer from solvent and residual monomers. Fouling in the heat exchanger may be reduced by adding to the solution from 0.01 to 100 ppm by weight of a polyoxyalkylene compound of the formula HO—(CH2CH2O)M[CH2CH(CH3)O]N(CH2CH2O)PH wherein M, N and P each represent the average number of repeating units and M is from 0 to 20, N is from 2 to 50 and P is from 0 to 20 and passing the solution through a heat exchanger to increase its temperature by at least 20° C.

Abstract: A process for separating ethylene glycol and 1,2-butanediol. A material flow containing ethylene glycol and 1,2-butanediol gets into the lower-middle part of the azeotropic rectification column C3 after the light components are removed by the separating columns C1 and C2, wherein the ethylene glycol and the azeotropic agent added from the top of the column form azeotrope which is distilled out from the top of the column and gets into the phase separator D1 after being condensed, the upper phase enriched with azeotropic agent after the phase was separated returns to the top of the column to continue to participate in azeotropy, and the lower phase enriched with ethylene glycol gets into the fourth separating column C4 to be refined to obtain the ethylene glycol product.

Abstract: This invention provides a method for purifying HFO-1234yf by removing HF from a mixture of HFO-1234yf and HF under simple and economically advantageous conditions.

Abstract: Solvent regeneration to recover a polar hydrocarbon (HC) selective solvent substantially free of hydrocarbons (HCs) and other impurities from a solvent-rich stream containing selective solvent, heavy HCs, and polymeric materials (PMs) generated from reactions among thermally decomposed or oxidized solvent, heavy HCs, and additives is provided. A combination of displacement agent and associated co-displacement agent squeezes out the heavy HCs and PMs from the extractive solvent within a solvent clean-up zone. Simultaneously, a filter equipped with a magnetic field is positioned in a lean solvent circulation line to remove paramagnetic contaminants. The presence of the co-displacement agent significantly enhances the capability of the displacement agent in removing the heavy HCs and PMs from the extractive solvent.

Abstract: The subject of the present invention is a method for preparing pyrocatechol from which the impurities resulting from the method for the preparation thereof have been removed. The method for preparing purified pyrocatechol from a crude pyrocatechol containing essentially pyrocatechol, small amounts of impurities including dihydroxybenzoquinone, and traces of hydroquinone and of phenolic compounds, is characterized in that it comprises at least the following steps: dissolution of the crude pyrocatechol in water, crystallization of the pyrocatechol, separation of the purified pyrocatechol and, optionally, a step of drying the purified pyrocatechol. The method of the invention may include other steps and, depending on the embodiment chosen, that may comprise a different series of steps, it is possible to obtain pyrocatechol with various degrees of purity.

Abstract: The invention relates to a method for removing water from a mixture containing at least one compound having at least one group reactive towards isocyanate and containing water, the mixture being applied to the surface of a rotating body A, the mixture flowing over the surface of the rotating body A to an outer region of the surface of the rotating body A and water evaporating from the mixture. In particular, this method is suitable for removing water from alcohols and amines.

Abstract: This invention provides a method for purifying HFO-1234yf by removing HF from a mixture of HFO-1234yf and HF under simple and economically advantageous conditions.

Abstract: Compounds, synthesis of, and methods for synthesizing metal alkoxide derivatives; and metal alkoxide derivatives for use as flame retardants are described. Group 13 metal alkoxides having flame retardant properties may be prepared by reacting the periodic table group 13 metalloid or metal trihydroxide with an alcohol.

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 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: 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: The invention concerns the use of at least one diol and/or of at least one trial as a an additive to dimethylsulfoxide (DMSO®) in order to lower the crystallization point of same. The DMSO formulation is used in combination with the aforementioned additive as a paint-stripping composition, a surface-cleaning composition, a graffiti-cleaning composition, a surface-cleaning composition in the microelectronics field as a photoresist stripping agent, a DMSO-based agrochemical composition or as a constituent of an aforementioned composition, as a solvent for dissolving polymers, or as a constituent of a composition that is usable in the field of cosmetology or pharmacy.

Abstract: A specific nonionic surfactant is added to a component mainly comprising hydrocarbons before passing through a heat exchanger in a petrochemical plant or a polyolefin production plant, whereby fouling of the heat exchanger can be efficiently prevented, that is, the performance of the heat exchanger can be prevented from being deteriorated, and long-term operation is feasible without sacrificing the speed of production. The nonionic surfactant is preferably a polyoxyalkylene compound represented by the general formula [I] below, more preferably a compound represented by the general formula [II] below. R1—O—[CH2—CH(R3)—O]k—R2[I] wherein R1, R2 and R3 are selected from a hydrogen atom, a C1 to C20 alkyl group, a C6 to C20 aryl group and a C1 to C20 acyl group, and may be the same or different from each other. HO—(CH2CH2O)m—[CH2CH(CH3)O]n—(CH2CH2O)pH[II] wherein m, n and p each represent the average number of repeating units, and m is in the range of 1 to 20, n is 2 to 50 and p is 1 to 20.

Abstract: A process for purifying propylene oxide characterized by subjecting a liquid reaction mixture containing propylene oxide, and water, hydrocarbons and oxygen-containing organic compounds as impurities obtained by reacting cumene hydroperoxide with propylene to extractive distillation using an extractant of a hydrocarbon having 7 to 20 carbon atoms with an extractive distillation column, and controlling a concentration of propylene glycol in the extractant supplied to the extractive distillation column to 20% by weight or less.

Abstract: This invention concerns a process for removing carbonyl-containing impurities from impure extractive distillation solvent such as a glycol, comprising: contacting the impure extractive distillation solvent with an acidic ion exchange resin. The purified extractive distillation solvent can be recycled for use as a solvent in an extractive distillation process that removes impurities from alkylene oxide. The extractive distillation solvent can be ethylene glycol monomethyl ether (EGME) used to purify propylene oxide.

Abstract: A process for the purification of fluoromethyl hexafluoroisopropyl ether which comprises contacting a crude composition comprising fluoromethyl hexafluoroisopropyl ether and hexafluoroisopropyl alcohol with a modifier in the presence of which the vapor pressure of the ether and/or the alcohol is modified whereby the difference in vapor pressure of the ether and the alcohol increases relative to the difference in vapor pressure of the ether and alcohol in the absence of the modifier and separating the ether from the alcohol.

Abstract: A method and apparatus for continuously producing an alkyl aryl ether and a diaryl carbonate by reacting a dialkyl carbonate and an aromatic alcohol in presence of a transesterification catalyst.

Abstract: Process for recovery of highly pure acrylonitrile by quickly vaporizing under vacuum the contaminated acrylonitrile as well as fresh acrylonitrile followed by contacting with hydrophilic agents in an extractive distillation column using plural number of packed sections.

Abstract: A process for the purification of a crude propene oxide containing methanol and acetaldehyde by a continuously operated extractive distillation using an extraction solvent lowering the volatility of methanol and feeding a compound containing an unsubstituted NH2 group capable of reacting with acetaldehyde to a distillation column at a point above the feeding point of the crude propene oxide to give a purified propene oxide containing less than 100 ppm methanol and less than 100 ppm acetaldehyde. There is also disclosed a process for the catalytic epoxidation of propene that includes this purification stage.

Abstract: The present invention relates to a process for the preparation of pure 2-chloro-5 -chloromethylthiazole by distillation in the presence of oligomeric polyethers.

Abstract: A process for the distillation of vinylaromatic monomers in the presence of 4-tert-butylcatechol (TBC) and oxygen, wherein no aromatic nitro or amino compound is present in any effective amount. The process is particularly suitable for destabilizing and purifying styrene which has been stabilized with 4-tert-butylcatechol (TBC) for transportation.

Abstract: This invention concerns a process for removing carbonyl-containing impurities from impure extractive distillation solvent such as a glycol, comprising: contacting the impure extractive distillation solvent with an acidic ion exchange resin. The purified extractive distillation solvent can be recycled for use as a solvent in an extractive distillation process that removes impurities from alkylene oxide. The extractive distillation solvent can be ethylene glycol monomethyl ether (EGME) used to purify propylene oxide.

Abstract: Process for recovery of highly pure acrylonitrile by quickly vaporizing under vacuum the contaminated acrylonitrile as well as fresh acrylonitrile followed by contacting with hydrophilic agents in an extractive distillation column using plural number of packed sections.

Abstract: A process for the purification of fluoromethyl hexafluoroisopropyl ether which involves contacting a crude composition fluoromethyl hexafluoroisopropyl ether and hexafluoroisopropyl alcohol with a modifier to modify the vapour pressure of the ether and/or the alcohol. The difference in vapour pressure of the ether and the alcohol increases relative to the difference in vapour pressure of the ether and alcohol in the absence of the modifier and enables separation of the ether from the alcohol. The modifier suitably is ammonia and/or an amine.

Abstract: The present invention relates to a process for the preparation of pure 2-chloro-5-chloromethylthiazole (CCMT) by distillation with addition of oligomeric polyethers.

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 method and apparatus for isolation of a barely volatile organic compound in a sample suspected to contain the same, e.g. a dioxin, which includes continuously adding superheated steam and a volatile and hardly water-soluble/water-insoluble solvent to a liquid or solid sample suspected to contain said organic compound to be isolated, a solid sample being dissolved in said solvent which can dissolve said organic compound to be isolated, distilling off an azeotropic mixture of said organic compound and said solvent by steam distillation, separating a solvent phase of said solvent dissolving said organic compound and said water phase, and recovering quantitatively said organic compound from said solvent. The dioxins are then further subjected to analysis, for example, GC, HRGC-MS and the like.

Abstract: A process for reducing the level(s) of water and/or other impurities from cyclosiloxanes by either azeotropic distillation, or by contacting the cyclosiloxane compositions with an adsorbent bed material. The purified cyclosiloxane material is useful for forming low-dielectric constant thin films having dielectric constants of less than 3.0, more preferably 2.8 to 2.0.

Abstract: Disclosed is a process for the recovery and purification of 3,4-epoxy-1-butene (epoxybutene) from mixtures comprising epoxybutene and aliphatic and aromatic hydrocarbons containing five to seven carbon atoms having boiling points between about 20° C. and 115° C. by means of extractive distillation of the epoxybutene using certain extractive distillation solvents.

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: A process for the distillation of vinylaromatic monomers in the presence of 4-tert-butylcatechol (TBC) and oxygen, wherein no aromatic nitro or amino compound is present in any effective amount. The process is particularly suitable for destabilizing and purifying styrene which has been stabilized with 4-tert-butylcatechol (TBC) for transportation.

Abstract: An industrial advantage process for producing high-purity 3-hydroxytetrahydrofuran easily and simply, which comprises reducing a 4-halo-3-hydroxybutyric acid ester (1) with a boron hydride compound and/or an aluminum hydride compound as a reducing agent in an organic solvent immiscible with water; treating the reaction mixture with an acid and water to thereby effect conversion to the corresponding 4-halo-1,3-butanediol and at the same time giving an aqueous solution containing said compound; carrying out the cyclization reaction of the 4-halo-1,3-butanediol in said aqueous solution; extracting the resulting 3-hydroxytetrahydrofuran from the 3-hydroxytetrahydrofuran-containing aqueous solution using an organic solvent immiscible with water; and isolating the 3-hydroxytetrahydrofuran by concentration and/or distillation of the solution obtained.

Abstract: A method of separating methanol and dimethyl carbonate in a distillation column through extractive distillation. The extractive distillation is conducted in the presence of an extractive distillation agent which modifies the azeotropic behavior of the dimethyl carbonate/methanol mixture. A vapor side stream is removed from the distillation column.

Abstract: Indene is produced from an indene-containing coal tar distillate by adding a glycol to the indene-containing coal tar distillate and then conducting azeotropic distillation to obtain an indene fraction while eliminating benzonitrile from the indene-containing coal tar distillate.

Abstract: 9,11- Diene C18 fatty acid cannot be separated from 10,12-Diene C18 fatty acid by conventional rectification because of the proximity of their boiling points. 9,11-Diene C18 fatty acid can be readily separated from 10,12-Diene fatty acid by azeotropic distillation. Effective agents are propyl formate, butyl ether, methyl pivalate and cyclopentanone.

Abstract: 3-Methyl-2-pentenal cannot be separated from 1-butanol by conventional rectification because of the proximity of their boiling points. 3-methyl-2-pentenal can be readily separated from n-butanol by azeotropic distillation. Effective agents are dimethoxymethane, petroleum ether and tetramethylortho-silicate.

Abstract: 2-Methyl-1-butanol and 3-methyl-1-butanol are difficult to separate from 1 pentanol by conventional distillation or rectification because of the proximity of their boiling points. 2-Methyl-1-butanol and 3-methyl-1-butanol can be easily separated from 1-pentanol by extractive distillation. Effective agents are 3-carene, propylene glycol phenyl ether and dimethylsulfoxide.

Abstract: Propylene oxide obtained by an epoxidation process which uses methanol as a solvent may be effectively treated to remove acetaldehyde by subjecting the crude epoxidation reaction product to fractional distillation. The methanol solvent is utilized during such distillation to lower the relative volatility of the acetaldehyde impurity, thereby making it possible to obtain a bottoms fraction containing substantially all the acetaldehyde. Purified propylene oxide having a reduced acetaldehyde concentration is removed as an overhead stream. Water may also be effectively separated from the propylene oxide using this procedure.

Abstract: 3-Methyl-2-pentenal cannot be separated from n-butanol by conventioal rectification because of the proximity of their boiling points. 3-methyl-2-pentenal can be readily separated from n-butanol by extractive distillation. Effective agents are 1-methyl-2-pyrrolidinone, 1,4-butanediol and phenol.

Abstract: Cumene cannot be separated from 3-ethyl toulene by distillation because of the proximity of their boiling points. They are readily separated by azeotropic distillation. Effective agents are methyl salicylate, diethylene glycol butyl ether and 3-nitrotoluene.

Abstract: A method of treating cleaning solvent used to clean mechanical parts. The method includes adding to the cleaning solvent a treating composition selected from the group of C.sub.5 -C.sub.14 alcohols, C.sub.2 -C.sub.8 dials, C.sub.10 -C.sub.14 polyols, and C.sub.4 -C.sub.14 glycol ethers, and mixtures thereof. A further embodiment includes the foregoing plus adding a clarifying agent from the group of aromatic, aliphatic and alkaryl sulfonic acids and sulfonic acid salts, esterified polyols, and alkyl phenol formaldehyde resins capped with alkoxy groups. The solvent is vaporized and condensed to effect recycling thereof without adding substituted quantities of treating composition to the solvent.

Abstract: 1,2,4-Trimethylbenzene is difficult to separate from 1,2,3-trimethylbenzene by conventional distillation or rectification because of the proximity of their boiling points. 1,2,4-trimethylbenzene can be readily separated from 1,2,3-trimethylbenzene by extractive distillation. Effective agents are 3-nitrotoluene, m-cresol and sulfolane.

Abstract: T-Amyl alcohol cannot be separated from n-butanol by distillation or rectification because of the closeness of their boiling points. T-Amyl alcohol is readily separated from n-butanol by extractive distillation. Effective agents are dimethylsulfoxide, N.N.dimethyl formamide and ethanolamine.

Abstract: An extractive distillation agent used for the distillation of propylene oxide contaminated with water, acetone, acetaldehyde and methanol and consisting essentially of ethylene glycol monomethyl ether is fed to an extractive distillation column within about 2 to about 15 stages from the top of the tower to obtain an overhead distillate fraction consisting of essentially anhydrous propylene oxide contaminated with reduced quantities of acetone, acetaldehyde and methanol, and a heavier bottoms distillation fraction containing substantially all of the ethylene glycol monomethyl ether, water and acetone and some of the methanol introduced into the distillation column.

Abstract: Acetone cannot be separated from a mixture of isopropanol and water because of the closeness of their boiling points. Acetone can be easily separated from isopropanol and water by extractive distillation. Effective extractive agents are 1-nitropropane, 3-carene, dimethylsulfoxide and 3-pentanone.