Separation of toluene from non-aromatic hydrocarbons by extractive distillation
OwnerLloyd Berginventor
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Abstract
Toluene is virtually impossible to separate from similar boiling non-aromatic hydrocarbons by conventional rectification or distillation. Toluene can be readily separated from similar boiling non-aromatic hydrocarbons by using extractive distillation in which the extractive agent is a mixture of phthalic anhydride and/or maleic anhydride plus a suitable solvent. A typical mixture comprises phthalic anhydride, maleic anhydride and glycerol triacetate.
Claims3
A method for separating toluene from close boiling non-aromatic hydrocarbons which comprises distilling a mixture of toluene and close boiling non-aromatic hydrocarbons in a rectification column in the presence of an effective amount of an extractive agent sufficient to provide a relative volatility of 2.5 or greater comprising effective proportions of phthalic anhydride and/or maleic anhydride and a solvent from the group consisting of glycerol triacetate, dimethylformamide, ethyl acetoacetate, acetonyl acetone, acetophenone, 2,4-pentanedione, ethylene glycol phenyl ether, dichlorodiethyl ether, dimethylacetamide, benzophenone, ethylene glycol diacetate, furfural, nitrobenzene, 2-nitrotoluene, sulfolane, phenol, dimethylsulfoxide.
Dependencies are inferred from the claim text.