Abstract: Formic acid cannot be completely removed from formic acid and water mixtures by distillation because of the presence of the maximum azeotrope. Formic acid can be readily removed from formic acid - water mixtures by extractive distillation in which the extractive agent is a benzoic acid derivative mixed with certain higher boiling organic compounds. Examples of effective agents are: o-toluic acid and heptanoic acid; 2-benzoylbenzoic acid and methyl salicylate; p-hydroxybenzoic acid, pelargonic acid and 2-hydroxyacetophenone.

Abstract: n-Propanol and t-amyl alcohol cannot be separated from each other by distillation because of the proximity of their boiling points. n-Propanol can be readily separated from t-amyl alcohol by using extractive distillation in which the extractive agent is a higher boiling organic compound or a mixture of two or more of these. Typical examples of effective agents are: methyl salicylate; benzyl benzoate and hexahydrophthalic anhydride; methyl salicylate, benzoic acid and hexahydrophthalic anhydride.

Abstract: Vinyl acetate cannot be easily removed from ethyl acetate by distillation because of the closeness of their boiling points. Vinyl acetate can be readily separated from ethyl acetate by means of extractive distillation. Typical effective agents are formic acid, formamide and formic acid-formamide mixture.

Abstract: An extractive distillation process for separating at least one cycloalkane from at least one close-boiling alkane employs as solvent a mixture of (a) at least one saturated C5-C9 alcohol (preferably cyclohexanol) and (b) at least one glycol compound (preferably tetraethylene glycol).

Abstract: Formic acid cannot be easily removed from acetic acid by distillation because of the closeness of their vapor pressures. Formic acid can be readily removed from acetic acid by extractive distillation. Typical extractive distillation agents are acetyl salicylic acid and butyl benzoate; acetyl salicylic acid and ethylene carbonate.

Abstract: Vinyl acetate cannot be easily removed from ethyl acetate by distillation because of the closeness of their boiling points. Vinyl acetate can be readily separated from ethyl acetate by means of extractive distillation using certain glycols or glycol ethers. Typical effective agents are 2-methyl -2,4-pentanediol, 1,3-butanediol, ethylene glycol methyl ether and diethylene glycol ethyl ether.

Abstract: Formic acid cannot be completely removed from formic acid and water mixtures by distillation because of the presence of the maximum azeotrope. Formic acid can be readily removed from formic acid--water mixtures by extractive distillation in which extractive agent is a dicarboxylic acid mixed with certain high boiling organic compounds. Examples of effective agents are: itaconic acid and diethylene glycol diethyl ether; azelaic acid, heptanoic acid and 2-hydroxyacetophenone.

Abstract: A phenolic polymerization inhibitor is recovered from a styrene distillation residue containing the phenolic polymerization inhibitor by a method which comprises extracting the inhibitor from the styrene distillation residue with an oxygen-containing organic solvent having not more than 6 carbon atoms, adding an aromatic hydrocarbon solvent to the oxygen-containing organic solvent phase consequently obtained, and subjecting the resultant mixture to distillation thereby separating the mixture into a solution of the phenolic polymerization inhibitor in the aromatic hydrocarbon solvent and the oxygen-containing organic solvent. The recovered solution is put to use as a polymerization inhibitor either in the unmodified form or in a form separated from the aromatic hydrocarbon solvent.

Abstract: 2-Pentanone cannot be completely removed from 2-pentanone and formic acid mixtures by distillation because of the presence of the maximum azeotrope. 2-Pentanone can be readily removed from 2-pentanone-formic acid mixtures by extractive distillation in which the extractive agent is a ketone, either alone or mixed with certain high boiling organic compounds. Examples of effective agents are cyclohexanone; diisobutyl ketone and octanoic acid; isophorone, hexanoic acid and butyl ether.

Abstract: 3-Methyl-2-butanone cannot be removed from 3-methyl-2-butanone and formic acid mixtures by distillation because of the presence of the maximum azeotrope between 3-methyl-2-butanone and formic acid. 3-Methyl-2-butanone can be readily removed from 3-methyl-2-butanone - formic acid mixtures by extractive distillation in which the extractive agent is dimethylacetamide, dimethylformamide or these with certain high boiling organic compounds.

Abstract: Isopropyl acetate cannot be completely removed from isopropyl acetate--isopropanol--water mixtures by distillation because of the presence of the minimum ternary azeotrope. Isopropyl acetate can be readily removed from mixtures containing it, isopropanol and water by using extractive distillation in which the extractive agent is a mixture of a polyol and one or higher boiling oxygenated, nitrogenous and/or sulfur containing organic compounds. Typical examples of effective agents are 1,3-butanediol and dimethylsulfoxide; 1,2,6-hexanetriol, dimethylsulfoxide and dimethylformamide.

Abstract: Dioxane cannot be completely removed from dioxane and formic acid mixtures by distillation because of the presence of the maximum azeotrope. Dioxane can be readily removed from dioxane - formic acid mixtures by extractive distillation in which the extractive agent is dimethylsulfoxide, either alone or admixed with certain high boiling organic compounds. Examples of effective agents are dimethylsulfoxide; DMSO and octanoic acid; DMSO, neodecanoic acid and methyl salicylate.

Abstract: Dioxane cannot be completely removed from dioxane and acetic acid mixtures by distillation because of the presence of the maximum azeotrope. Dioxane can be readily removed from dioxane - acetic acid mixtures by extractive distillation in which the extractive agent is N,N-dimethylacetamide or dimethylformamide, either alone or mixed with certain high boiling organic compounds. Examples of effective agents are N,N-dimethylacetamide; dimethylformamide and heptanoic acid; N,N-dimethylacetamide, heptanoic acid and diethylene glycol diethyl ether.

Abstract: Dioxane cannot be completely removed from dioxane and acetic acid mixtures by distillation because of the presence of the maximum azeotrope. Dioxane can be readily removed from dioxane-acetic acid mixtures by extractive distillation in which the extractive agent is dimethylsulfoxide, either alone or mixed with certain high boiling organic compounds. Examples of effective agents are dimethylsulfoxide; DMSO and octanoic acid; DMSO, hexanoic acid and isophorone.

Abstract: 2-Pentanone cannot be completely removed from 2-pentanone and formic acid mixtures by distillation because of the presence of the maximum azeotrope. 2-Pentanone can be readily removed from 2-pentanone formic acid mixtures by extractive distillation in which the extractive agent is dimethylsulfoxide, either alone or mixed with certain high boiling organic compounds. Examples of effective agents are dimethylsulfoxide; DMSO and octanoic acid; DMSO, hexanoic acid and isophorone.

Abstract: Formic acid cannot be completely removed from formic acid and water mixtures by distillation because of the presence of the maximum azeotrope. Formic acid can be readily removed from formic acid - water mixtures by extractive distillation in which the extractive agent is ethylene carbonate or propylene carbonate, either alone or mixed with certain high boiling organic compounds. Examples of effective agents are ethylene carbonate and heptanoic acid; propylene carbonate, benzoic acid and isophorone; propylene carbonate, heptanoic acid and 2-hydroxyacetophenone.

Abstract: A process for purifying diethoxymethane from a mixture containing ethanol and, optionally, water. The process involves the addition of an amount of water, DEM, or an appropriate mixture of any two or three of water, DEM and ethanol that is effective in moving the mixture into the two liquid phase region on an equilibrium tie-line which crosses the critical distillation boundary without the need for additional azeotrope-forming agents such as cyclohexane.

Abstract: m-Xylene is difficult to separate from o-xylene by conventional rectification or distillation because of the close proximity of their boiling points. m-Xylene can be readily separated from o-xylene by using extractive distillation in which the extractive agent is ethyl-2-hydroxybenzoate; methyl benzoate plus benzophenone; methyl benzoate, butyl benzoate and dimethylsulfoxide.

Abstract: Impure formic acid cannot be completely removed from formic acid-water-impurity mixtures by distillation because of the presence of the maximum azeotrope between formic acid and water. Formic acid can be readily removed from mixtures containing it, water and impurities of the ether, ester, ketone or diketone type by using extractive distillation in which the extractive agent is a higher boiling oxygenated, nitrogenous or sulfur containing organic compound or a mixture of these. Examples of effective agents are adiponitrile; sulfolane and salicyclic acid; dimethylformamide, N,N-dimethylacetamide and ethylene glycol ethyl ether acetate.

Abstract: Isopropanol cannot be completely removed from isopropanol-isopropyl acetate-water mixtures by distillation because of the presence of the minimum ternary azeotrope. Isopropanol can be readily removed from mixtures containing it, isopropyl acetate and water by using extractive distillation in which the extractive agent is a higher boiling ester of phthalic acid. Typical examples of effective agents are diisooctyl phthalate and methyl benzoate, dibutyl phthalate, methyl benzoate and nitromethane.

Abstract: 2-Butyl acetate cannot be completely removed from 2-butyl acetate-2-butanol-water mixtures by distillation because of the presence of the minimum ternary azeotrope. 2-butyl acetate can be readily removed from mixtures containing it, 2-butanol and water by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, nitrogenous and/or sulfur containing organic compound or a mixture of these. Typical examples of effective agents are N,N-dimethylacetamide; dimethylformamide and ethylene glycol; acetamide, dimethylsulfoxide and ethylene glycol.

Abstract: Isopropanol and t-butanol cannot be separated from each other by distillation because of the proximity of their boiling points. Isopropanol can be readily separated from t-butanol by using extractive distillation in which the extractive agent is a higher boiling oxygenated organic compound or a mixture of two or more of these. Typical examples of effective agents are: methyl benzoate; methyl benzoate and hexahydrophthalic anhydride; phthalic anhydride, hexahydrophthalic anhydride and methyl benzoate.

Abstract: n-Hexyl acetate cannot be completely removed from n-hexyl acetate- n-hexyl alcohol- water mixtures by distillation because of the presence of the minimum ternary azeotrope. n-Hexyl acetate can be readily removed from mixtures containing it, n-hexyl alcohol and water by using extractive distillation in which the extractive distillation agent is dimethylsulfoxide or a mixture of DMSO with a higher boiling organic compound. Typical examples of effective agents are DMSO; DMSO and tetraethylene glycol; DMSO, dimethylformamide and hexylene glycol.

Abstract: Isopropyl acetate cannot be completely removed from isopropyl acetate - isopropanol - water mixtures by distillation because of the presence of the minimum ternary azeotrope. Isopropyl acetate can be readily removed from mixtures containing it, isopropanol and water by using extractive distillation in which the extractive agent is a higher boiling oxygenated or nitrogenous organic compound or a mixture of these. Typical examples of effective agents are diethanolamine; ethanolamine and N-methyl pyrrolidone; triethanolamine and N-methyl pyrrolidone.

Abstract: t-Amyl alcohol and isobutanol cannot be separated from each other by distillation because of the proximity of their boiling points. t-Amyl alcohol can be readily separated form isobutanol by using extractive distillation in which the extractive agent is a higher boiling organic compound or a mixture of two or more of these. Typical examples of effective agents are: dimethylsulfoxide; dimethylsulfoxide and N,N-dimethylacetamide; dimethylsulfoxide, dimethylformamide and phthalic anhydride.

Abstract: n-Amyl acetate cannot be completely removed from n-amyl acetate - n-amyl alcohol - water mixtures by distillation because of the presence of the minimum ternary azeotrope. n-Amyl acetate can be readily removed from mixtures containing it, n-amyl alcohol and water by using extractive distillation in which the extractive distillation agent is a higher boiling organic compound or a mixture of these. Typical examples of effective agents are ethylene glycol; propylene glycol and dimethylsulfoxide; 1,3-butanediol, dimethylformamide and acetamide.

Abstract: The production of solutions of hydrogen peroxide in phenol or its derivatives, e.g. hydrocarbyl substituted phenols, halo substituted phenols or phenol ethers, is carried out in a single step. Practically no loss of hydrogen peroxide occurs since a total distillation of hydrogen peroxide together with phenol or phenol derivative is avoided. Simultaneously the solutions obtained are practically free from water. The mixture of phenol or phenol derivative and aqueous hydrogen peroxide is treated with a material that boils below the boiling point of hydrogen peroxide, phenol or phenol derivative or forms an azeotrope with water that boils below the boiling point of hydrogen peroxide, phenol or phenol derivative and the water removed as an azeotrope. The solution of hydrogen peroxide in phenol or phenol derivative which remains behind is suitable for carrying out oxidation reactions and above all, also for hydroxylation reactions.

Abstract: m-Xylene is difficult to separate from o-xylene by conventional rectification or distillation because of the close proximity of their boiling points. m-Xylene can be readily separated from o-xylene by using extractive distillation in which the extractive agent is dimethylformamide; dimethylformamide and 1,4-butanediol; dimethylformamide, adiponitrile and dihexyl phthalate.

Abstract: m-Xylene is difficult to separate from o-xylene by conventional distillation or rectification because of the close proximity of their boiling points. m-Xylene can be readily separated from o-xylene by using extractive distillation in which the extractive agent is adiponitrile or a mixture of it with certain high boiling organic compounds. Typical examples of effective agents are: adiponitrile; adiponitrile and 1,4-butanediol; adiponitrile, ethylene carbonate and benzyl alcohol.

Abstract: n-Propyl acetate cannot be completely removed from n-propyl acetate - n-propanol - water mixtures by distillation because of the presence of the minimum ternary azeotrope. n-Propyl acetate can be readily removed from mixtures containing it, n-propanol and water by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated or nitrogenous organic compound or a mixture of these. Typical examples of effective agents are N-methylpyrrolidone; triethanolamine; N-methylpyrrolidone and ethylene glycol.

Abstract: Isopropanol cannot be completely removed from isopropanol-isopropyl acetate-water mixtures by distillation because of the presence of the minimum ternary azeotrope. Isopropanol can be readily removed from mixtures containing it, isopropyl acetate and water by using extractive distillation in which the extractive agent is a higher boiling ester of phthalic acid. Typical examples of effective agents are diethyl phthalate, diisooctyl phthalate and methyl benzoate, dibutyl phthalate, methyl benzoate and nitromethane.

Abstract: Isopropyl ether cannot be completely removed from isopropyl ether--isopropanol--water mixtures by distillation because of the presence of the minimum ternary azeotrope. Isopropyl ether can be readily removed from mixtures containing it, isopropanol and water by using extractive distillation in which the extractive distillation agent is a higher boiling glycol, glycol ether or a mixture of them. Typical examples of effective agents are ethylene glycol, propylene glycol, diethylene glycol diethyl ether plus propylene glycol ethyl ether.

Abstract: Isopropanol cannot be completely removed from isopropanol - isopropyl acetate - water mixtures by distillation because of the presence of the minimum ternary azeoptrope. Isopropanol can be readily removed from mixtures containing it, isopropyl acetate and water by using extractive distillation in which the extractive agent is a higher boiling benzoate or nitro paraffin. Typical examples are methyl benzoate; methyl benzoate and nitromethane; butyl benzoate, nitromethane and nitroethane.

Abstract: Water cannot be completely removed from ethanol by distillation because of the presence of the minimum azeotrope. Ethanol can be readily dehydrated by using extractive distillation in which the water is removed as overhead product and the ethanol and extractive agent as bottoms and subsequently separated by conventional rectification. Typical examples of suitable extractive agents are hexahydrophthalic anhydride; methyl tetrahydrophthalic anhydride and pentanol-1; trimellitic anhydride, ethyl salicylate and resorcinol.

Abstract: Formic acid cannot be completely removed from formic acid - water mixtures by distillation because of the presence of the maximum azeotrope. Formic acid can be readily removed from mixtures containing it and water by using extractive distillation in which the extractive distillation agent is a sulfone. Typical examples of effective agents are thiophan sulfone; dimethyl sulfone and adiponitrile; phenyl sulfone, adiponitrile and acetophenone.

Abstract: Water cannot be completely removed from ethanol by distillation because of the presence of the minimum azeotrope. Ethanol can be readily dehydrated by using extractive distillation in which the water is removed as overhead product and the ethanol and extractive agent as bottoms and subsequently separated by conventional rectification. Typical examples of suitable extractive agents are methyl benzoate; trimellitic anhydride and methyl benzoate; dipropylene glycol dibenzoate, ethyl salicylate and resorcinol.

Abstract: Acetone cannot be completely removed from acetone-methanol mixtures by distillation because of the presence of the minimum boiling azeotrope. Acetone can be readily separated from methanol by using extractive distillation in which the extractive agent is dimethylformamide, either alone or admixed with other compounds. Typical examples of effective agents are: dimethylformamide; dimethylformamide and diethylene glycol; dimethyl formamide, glycerine and propylene glycol.

Abstract: Methyl acetate cannot be completely removed from methyl acetate - methanol mixtures by distillation because of the presence of the minimum binary azeotrope. Methyl acetate can be readily removed from mixtures containing it and methanol by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, nitrogenous and/or sulfur containing organic compound or a mixture of these. Typical examples of effective agents are dimethylformamide; dimethylsulfoxide plus tetraethylene glycol, dimethylsulfoxide plus 1,5-pentanediol plus 1,6-hexanediol.

Abstract: n-Propyl acetate cannot be completely removed from n-propyl acetate - n-propanol - water mixtures by distillation because of the presence of the minimum ternary azeotrope. n-Propyl acetate can be readily removed from mixtures containing it, n-propanol and water by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, nitrogenous and/or sulfur containing organic compound or a mixture of these. Examples of effective agents are N,N-dimethylacetamide; acetamide and triethylene glycol; acetamide and N,N-dimethylacetamide and triethanolamine.

Abstract: m-Xylene is difficult to separate from o-xylene by conventional rectification or distillation because of the close proximity of their boiling points. m-Xylene can be readily separated from o-xylene by using extractive distillation in which the extractive agent comprises propoxypropanol; propoxypropanol and 1,4-butanediol; ethyl benzoate and ethylene glycol phenyl ether and benzyl alcohol.

Abstract: Acetone cannot be completely removed from acetone-methanol mixtures by distillation because of the presence of the minimum boiling azeotrope. Acetone can be readily separated from methanol by using extractive distillation in which the extractive agent is a higher boiling oxygenated, nitrogenous and/or sulfur-containing organic compound or a mixture of two or more of these. Typical examples of effective agents are: Glycerine, 1,5-Pentanediol, Dimethylsulfoxide, n-Hexanol, Dioctyl phthalate and N,N-Dimethylacetamide.

Abstract: Ethyl acetate cannot be completely removed from ethanol and water mixtures by distillation because of the presence of the minimum ternary azeotrope. Ethyl acetate can be readily removed from mixtures containing it, ethanol and water by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, sulfur containing or nitrogenous organic compound or a mixture of these. Typical examples of effective agents are: 1,4-butanediol; ethylene glycol-1,5-pentanediol; propylene glycol-tetraethylene glycol-polyethylene glycol; glycerine-propylene glycol-tetraethylene glycol-1,4-butanediol.

Abstract: Isopropyl ether cannot be completely removed from isopropyl ether-isopropanol-water mixtures by distillation because of the presence of the minimum ternary azeotrope. Isopropyl ether can be readily removed from mixtures containing it, isopropanol and water by using extractive distillation in which the extractive distillation agent is dimethylsulfoxide with or without a mixture of higher boiling oxygenated and/or nitrogenous organic compounds. Typical examples are dimethylsulfoxide; dimethylsulfoxide and ethylene glycol; dimethylsulfoxide, dimethylformamide and 1,4-butanediol.

Abstract: A process for producing anhydrous ethanol from an ethanol-water mixture feedstock comprising subjecting the feedstock to distillation in a first distillation zone to produce an overhead vapor of from about 80 to about 90 weight percent ethanol, subjecting the thus produced overhead vapor to extractive distillation in an extractive distillation zone to produce anhydrous ethanol vapor overhead of about 99.5 weight percent ethanol and a solvent-rich bottom stream, and stripping the solvent-rich bottom stream and recycling the thus produced lean solvent bottom stream to the extractive distillation zone and recycling the thus produced overhead vapor stream to the first distillation zone. Also disclosed is a system for performing the process.

Abstract: Isopropyl ether cannot be completely removed from isopropyl ether-acetone mixtures by distillation because of the presence of the minimum binary azeotrope. Isopropyl ether can be readily removed from mixtures containing it and acetone by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, nitrogenous and/or sulfur containing compound or a mixture of these. Typical examples of effective agents are: dimethylsulfoxide; sulfolane and propylene glycol; adiponitrile, glycerine and ethylene glycol.

Abstract: Methanol cannot be completely removed from methanol-methyl acetate mixtures by distillation because of the presence of the minimum binary azeotrope. Methanol can be readily removed from mixtures containing it and methyl acetate by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated or nitrogenous organic compound or a mixture of these. Typical examples of effective agents are: ethylene glycol phenyl ether, ethylene carbonate, nitromethane, 2-nitrotoluene, 1-nitropropane plus propylene carbonate.

Abstract: Isopropyl ether cannot be completely removed from isopropyl ether - methyl ethyl ketone mixtures by distillation because of the presence of the minimum binary azeotrope. Isopropyl ether can be readily removed from mixtures containing it and methyl ethyl ketone by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated and/or nitrogenous organic compound or a mixture of these. Typical examples of effective agents are adiponitrile; ehtylene carbonate plus dimethylformamide; adiponitrile plus dimethylformamide plus glycerine.

Abstract: Methyl acetate cannot be completely removed from methyl acetate-methanol mixtures by distillation because of the presence of the minimum binary azeotrope. Methyl acetate can be readily removed from mixtures containing it and methanol by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, nitrogenous and/or sulfur containing organic compound or a mixture of these. Typical examples of effective agents are dimethylsulfoxide; glycerine plus propylene glycol; ethylene glycol plus DMSO plus 1,5-pentanediol. Methanol can be removed as the overhead product from methyl acetate when the extractive distillation agent is nitrobenzene, propylene carbonate or ethylene glycol phenyl ether.

Abstract: n-Butyl acetate cannot be completely removed from n-butyl acetate - n-butanol - water mixtures by distillation because of the presence of the minimum ternary azeotrope. n-Butyl acetate can be readily removed from mixtures containing it, n-butanol and water by using extractive distillation in which the extractive distillation agent is a higher boiling oxygenated, nitrogenous and/or sulfur containing organic compound or a mixture of these. Typical examples of effective agents are dimethylsulfoxide; dimethylsulfoxide and 1,4-butanediol; dimethylsulfoxide, dimethylformamide and 1,6-hexanediol.

Abstract: Benzene is virtually impossible to separate from similar close boiling non-aromatic hydrocarbons by conventional rectification or distillation. Benzene can be readily separated from similar boiling non-aromatic hydrocarbons by using extractive distillation in which the extractive agent is a mixture of benzoic acid, maleic anhydride and/or phthalic anhydride plus a suitable solvent. A typical mixture comprises phthalic anhydride, maleic anhydride and adiponitrile.