Abstract: A mixture contains one or more vinyl-containing compounds as component (A) and, as a further component, a stabilizer (B) which contains one or more readily volatile nitroxyl compounds as component (b1), one or more sparingly volatile nitroxyl compounds as component (b2), if required one or more aromatic nitro compounds as component (b3) and, if required, one or more iron compounds as component (b4). Stabilizers (B) contain the components (b1) and (b2), (b1) and (b2) and (b3), (b1) and (b2) and (b4), and (b1), (b2), (b3) and (b4), and the premature polymerization of vinyl-containing compounds during their purification or distillation is inhibited by a process in which a stabilizer (B) is added or the components of stabilizer (B) are added as individual substances or in at least two groups of the components.

Abstract: Nitrogen trifluoride (NF3) containing less than 10 parts-per-million molar impurities, e.g., tetrafluoromethane (PFC-14), is disclosed. Azeotropic and extractive distillation processes using entraining agents for separating NF3 and PFC-14 from each other and from mixtures with other electronics industry materials are disclosed.

Abstract: An apparatus for producing phenol and acetone from cumene hydroperoxide comprises a reactive distillation column comprising at its upper portion a distillation column and at its lower portion a catalyst bed.

Abstract: A method of separating aromatic hydrocarbons and non-aromatic hydrocarbons, and aromatic hydrocarbons and naphtenes involves distilling a mixture of the components by an extractive distillation process in the presence of an extractive distillation solvent. The extractive distillation solvent may be an ester of a dibasic acid, an acetonyl acetone or morpholine.

Abstract: A method of separating methanol and acetone, and methanol and methyl acetate involves distilling a mixture of the components by an extractive distillation process in the presence of an extractive distillation solvent. The extractive distillation solvent may be an amine, a chlorinated hydrocarbon, a brominated hydrocarbon, a paraffin, and an alkylated thiopene.

Abstract: A method for efficiently resolving optical isomers, in which a discriminating liquid consisting of a discriminating agent capable of discriminating optical isomers and a diluent are brought into contact with a mixture containing said optical isomers in countercurrent flow, to resolve the optical isomers by adsorption separation, distillation separation, absorption separation or membrane separation, and recovered at an optical isomer content of 5 wt % or less for recycled use, under one or more of the following conditions: (a) the dielectric constant of the diluent is 30 or less and the viscosity of the discriminating liquid is 0.

Abstract: A method of separating ethanol and ethyl acetate, and ethanol and water involves distilling a mixture of the components by an extractive distillation process in the presence of an extractive distillation solvent. The extractive distillation solvent may be an amine, an alkylated thiopene, and paraffins.

Abstract: A method for separating sulfur species from hydrocarbon streams, particularly cracked naphtha streams, using extractive distillation. The method effectively separates sulfur species from cracked naphtha streams without substantially lowering the olefin content.

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: A perfluorovinyl ether of the formula: RfO(CF2CFXO)nCF═CF2  (1) in which Rf is a perfluoralkyl group, X is a fluorine atom or a trifluoromethyl group, and n is a number of 0 to 20 containing impurities is purified by removing a hydrogen fluoride adduct of the perfluorovinyl ether (1) through distillation, the perfluorovinyl ether (1) is distilled in the presence of a ketone or an ether having a lower boiling point than that of the perfluorovinyl ether (1) while refluxing such a solvent. This method can remove the hydrogen fluoride adduct of a perfluorovinyl ether as an impurity and provide a high purity perfluorovinyl ether.

Abstract: A process for recovering glycols from used glycol-containing technical fluids, especially from used antifreeze comprises adding to the used glycol-containing technical fluids an organic solvent which forms with the glycol to be separated off an azeotropic mixture which has a lower boiling point than the glycol itself and distilling off this azeotropic mixture.

Abstract: In a process for the preparation of methylglyoxal dimethyl acetal from methylglyoxal and methanol in the presence of an acidic ion exchanger, water is introduced in an amount sufficient to form an acidic reaction mixture in which the acetal product and water form an azeotropic mixture, with or without the retention of some methanol reactant. After subjecting a single phase acidic reaction mixture to an azeotropic distillation, it will separate into two distinct liquid phases with a simple recovery of the acetal product from the aqueous phase.

Abstract: There is provided a process of effectively separating pentafluoroethane (HFC-125) from a mixture of HFC-125 and chloropentafluoroethane (CFC-115). When the mixture of HFC-125 and CFC-115 is subjected to an extractive distillation to obtain a concentrated HFC-125, ethyleneglycol-based compounds (3) having a general formula: R1O(CH2CH2O)nR2 wherein R1 and R2 may be the same or different and are each independently selected from the group consisting of hydrogen and an alkyl group having 1 to 4 carbon atoms, and n is an integer with a value from 1 to 3 is used as an extractant, whereby CFC-115 is obtained as a distillate product (4) and a mixture of HFC-125 and the extractant as a bottom product (5) is obtained. Then, the extractant is separated from HFC-125 by distilling the mixture and re-used in the extractive distillation.

Abstract: A method and apparatus for recycling and recovering potentially explosive solvents includes providing a contaminated solvent to a distillation tank, vaporizing the solvent in the distillation tank, thereby producing solvent vapor, condensing the solvent vapor, and adding a free radical scavenger substance to the distillation tank during the heating step. The vapor is then condensed and collected in a clean solvent tank where additional free radical scavenger substance is added to the clean solvent tank. Preferably, contaminated solvent is introduced into the solvent recovery system by providing contaminated solvent into contaminated solvent tank which is connected to the distillation tank, and an oxygen displacer substance is provided to the contaminated solvent tank and the clean solvent tank so as to minimize the amount of free oxygen in the tanks.

Abstract: Inhibition of the formation of unsaturated carbon compounds during the heating of 141b involving the addition of various inhibitors such as dialkylhydroxylamine and/or the use of a vessel made of a nickel alloy.

Abstract: Mesitylene is difficult to separate from 1,2,4-Trimethylbenzene because of the proximity of their boiling points. They are readily separated by azeotropic distillation. Effective agents are isopropyl acetate, 2-pentanol and acetonitrile.

Abstract: The invention relates to a method for purifying a crude 1,1,1,3,3-pentafluoropropane (HFC-245fa) containing HFC-245fa and 1-chloro-3,3,3-trifluoro-trans-1-propene (HCFC-1233zd(t)), by distillation. This method is characterized in that the distillation is conducted in the presence of a solvent having a boiling point which is higher than that of HCFC-1233zd(t), thereby to substantially remove HCFC-1233zd(t) from the crude HFC-245fa. This solvent may be selected from carbon chlorides, chlorohydrocarbons, fluorochlorohydrocarbons, saturated hydrocarbons, and mixtures thereof. With the use of this solvent, it becomes possible to substantially easily separate HFC-245fa from HCFC-1233zd(t).

Abstract: When a nitroxyl compound is heated in an oxygen-free atmosphere with a vinyl aromatic monomer at 50-140.degree. C. for up to 60 days, it forms an activated inhibitor mixture which is superior to the nitroxyl compound itself in preventing the premature polymerization of a vinyl aromatic monomer during its processing and purification.

Abstract: A method for removing a high boiling solvent from a pharmaceutical composition dissolved in the high boiling solvent comprising adding a low boiling co-solvent to the solution to form a mixture of the high boiling solvent and the low boiling co-solvent, and removing the solvent/co-solvent mixture under vacuum.

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: A process for the purification of pentafluoroethane (F125) containing chloropentafluoroethane (F115). The F125-F115 mixture to be purified is subjected to an extractive distillation, the extractant being a C.sub.5 -C.sub.8 perfluoroalkyl halide.

Abstract: Mesitylene cannot be separated from 4-ethyl toluene by distillation because of the proximity of their boiling points. They are readily separated by azeotropic distillation. Effective agents are isopropyl palmitate, triacetin and methyl salicylate.

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: 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: Ethyl acetate cannot be separated from ethanol by distillation or rectification because of the closeness of their boiling points. Ethyl acetate is readily separated from ethanol by azeotropic distillation. Effective agents are ethyl ether, methyl formate and cyclohexane.

Abstract: Mixtures of allyl alcohol and n-propanol are separated by extractive distillation using propylene carbonate, N-methyl pyrrolidone or gamma-butyrolactone extractive distillation 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: Linoleic acid cannot be separated from linolenic acid by distillation or rectification because of the closeness of their boiling points. Linoleic acid is readily separated from linolenic acid by azeotropic distillation. Effective agents are nonane, dimethyl formamide, 2-nitropropane and pentyl propionate.

Abstract: A process for the purification of 1-chloro-1,2,2,2-tetrafluoroethane (F124) containing 1,2-dichlorotetrafluoroethane (F114) and/or 1,1-dichlorotetrafluoroethane (F114a). The F124 to be purified is subjected to extractive distillation, the extractant being chosen from C.sub.5 -C.sub.8 aliphatic or cycloaliphatic hydrocarbons and C.sub.4 -C.sub.8 perfluoroalkyl halides.

Abstract: There is provided a process of effectively separating pentafluorethane (HFC-125) out of a mixture of HFC and chloropentafluoroethane (CFC-115). When the mixture of HFC-125 and CFC-115 is subjected to extractive distillation so as to obtain concentrated HFC-125, methanol, ethanol, butanol, propyl alcohol, pentafluoropropanol, tetrafluoropropanol or acetone is used as an extractant, whereby CFC-115 is obtained as a distillate product and a mixture of HFC-125 and the extractant is separated from HFC-125 by distilling the mixture and re-used in the extractive distillation.

Abstract: 2-Methyl-1-propanol cannot be separated from t-amyl alcohol by distillation or rectification because of the closeness of their boiling points. 2-Methyl-1-propanol is readily separated from t-amyl alcohol by azeotropic distillation. Effective agents are butyl propionate, cyclohexane and 2,2-dimethoxypropane.

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 azeotropic distillation. Effective agents are propyl acetate, tetrahydrofuran and heptane.

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.

Abstract: 2-Butanol cannot be sparated from t-amyl alcohol by distillation or rectification because of the closeness of their boiling points. 2-Butanol is readily separated from t-amyl alcohol by extractive distillation. Effective agents are butyl ether, benzyl acetate and 1,2,4-trimethyl benzene.

Abstract: Methyl ethyl ketone cannot be separated from ethanol by distillation or rectification because of the closeness of their boiling points. Methyl ethyl ketone is readily separated from ethanol by extractive distillation. Effective agents are methyl benzoate, phenol, glycerol and nitroethane.

Abstract: Methyl ethyl ketone cannot be separated from ethanol by distillation or rectification because of the closeness of their boiling points. Methyl ethyl ketone is readily separated from ethanol by azeotropic distillation. Effective agents are amyl acetate, methyl formate, 2,2-dimethyl butane and 2,3-dimethyl butane.

Abstract: Applicants have developed a process for inhibiting the polymerization of vinyl aromatic compound during the distillation of the vinyl aromatic compounds. The process involves adding to the vinyl aromatic compound, e.g., styrene, a nitroso compound such as N-nitroso-N, N'-di-3-pentyl-p-phenylenediamine.

Abstract: 4-Methyl-2-pentanol cannot be separated from 3-methyl-1-butanol by distillation because of the closeness of their boiling points. 4-Methyl-2-pentanol can be easily separated from 3-methyl-1-butanol by extractive distillation. Effective agents are dodecane, dimethylformamide and dimethylsulfoxide.

Abstract: 3-Carene is difficult to separate from limonene by conventional distillation or rectification because of the proximity of their boiling points. 3-Carene can be readily separated from limonene by extractive distillation. Effective agents are o-cresol, 2,6-dimethyl-4-heptanone and triethylene glycol.

Abstract: There is provided a purification process for dimethoxymethylsilane in which a mixture containing dimethoxymethylsilane and methanol is subjected to a first distillation step in which the mixture is distilled in the presence of methyl formate or methoxytrimethylsilane so that a distillate fraction containing methanol and methyl formate or methoxytrimethylsilane is distilled off and a balance fraction containing dimethoxymethylsilane and methanol is discharged, the amount of methanol in the balance fraction being substantially reduced relative to that of the mixture.

Abstract: Ethanol, isopropanol and water cannot be separated from each other by distillation or rectification because of minimum azeotropes. They are readily separated by extractive distillation. Effective agents are: dimethylsulfoxide for ethanol, phenol for isopropanol.

Abstract: 2-Butanol cannot be separated from isobutanol by distillation or rectification because of the closeness of their boiling points. 2-Butanol is readily separated from isobutanol by extractive distillation. Effective agents are propylene glycol propyl ether, 2-methoxyethanol and ethyl acetate.

Abstract: The present invention provides an improved process for production of acrylic acid by subjecting propylene and/or acrolein to catalytic gas-phase oxidation with a molecular oxygen-containing gas. In the process, the mixed gas obtained by the catalytic gas-phase oxidation is contacted with an aqueous collecting agent containing acrylic acid, acetic acid and a poorly-soluble-in-water solvent, to form an aqueous acrylic acid solution; and the aqueous acrylic acid solution is subjected to azeotropic distillation in the presence of a poorly-soluble-in-water solvent to remove by-products and obtain high-purity acrylic acid.

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 azeotropic distillation. Effective agents are toluene, methyl acetate and tetrahydrofuran.

Abstract: 4-Methyl-2-pentanol cannot be separated from 3-methyl-1-butanol by distillation because of the closeness of their boiling points. 4-Methyl-2-pentanol can be easily separated from 3-methyl-1-butanol by azeotropic distillation. Effective agents are m-xylene and cumene.

Abstract: 1-Propanol cannot be separated from t-amyl alcohol by distillation or rectification because of the closeness of their boiling points. 1-Propanol is readily separated from t-amyl alcohol by azeotropic distillation. Effective agents are heptane, ethyl acetate and tetrahydrofuran.

Abstract: 1-Propanol and t-amyl alcohol cannot be separated by distillation or rectification because of the closeness of their boiling points. 1-Propanol is readily separated from t-amyl alcohol by extractive distillation. Effective agents are dipentene, amyl acetate and 1,4-dioxane.