Separation of benzene from non-aromatic hydrocarbons by extractive distillation

Claim 1

A method for separating benzene from close boiling non-aromatic hydrocarbons which comprises distilling a mixture of benzene and close boiling non-aromatic hydrocarbons in a rectification column in the presence of a sufficient amount of an extractive agent to provide a relative volatility of 2.0 or greater comprising effective proportions of at least phthalic anhydride and at least one solvent from the group consisting of acetophenone, adiponitrile, anisole, benzophenone, benzyl acetate, butoxypropanol, butyl benzyl phthalate, diethyl maleate, diethyl oxalate, diethylene glycol, N,N-dimethyl acetamide, N(N,N-dimethylaminopropyl)-2-pyrrolidine, dimethylformamide, dimethylsulfone, dimethylsulfoxide, dipropylene glycol, ethyl acetoacetate, ethylene glycol diacetate, ethylene glycol phenyl ether, formamide, furfural, glycerol triacetate, isobornyl acetate, isophorone, N-isopropyl-2-pyrrolidone, 1-methyl-2-pyrrolidinone, nitrobenzene, 2-nitrotoluene, 3-nitrotoluene, n-octanol, 2,4-pentanedione, phenol, phenyl acetate, phenyl acetic acid, sulfolane, sulfolene, tetrahydrofurfuryl alcohol, and triethylene glycol diacetate.

Claim 2

A method for separating benzene from close boiling non-aromatic hydrocarbons which comprises distilling a mixture of benzene and close boiling non-aromatic hydrocarbons in a rectification column in the presence of a sufficient amount of an extractive agent to provide a relative volatility of 2.0 or greater comprising effective proportions of at least phthalic anhydride and at least one solvent from the group consisting of acetophenone, adiponitrile, anisole, benzophenone, benzyl acetate, butoxypropanol, butyl benzyl phthalate, diethyl maleate, diethyl oxalate, diethylene glycol, N,N-dimethyl acetamide, N(N,N-dimethylaminopropyl)-2-pyrrolidine, dimethylformamide, dimethylsulfone, dimethylsulfoxide, dipropylene glycol, ethyl acetoacetate, ethylene glycol diacetate, ethylene glycol phenyl ether, formamide, furfural, glycerol triacetate, isobornyl acetate, isophorone, N-isopropyl-2-pyrrolidone, 1-methyl-2-pyrrolidinone, nitrobenzene, 2-nitrotoluene, 3-nitrotoluene, n-octanol, 2,4-pentanedione, phenol, phenyl acetate, phenyl acetic acid, sulfolane, sulfolene, tetrahydrofurfuryl alcohol, and triethylene glycol diacetate.

Claim 4

A method for separating benzene from close boiling non-aromatic hydrocarbons which comprises distilling a mixture of benzene and close boiling non-aromatic hydrocarbons in a rectification column in the presence of a sufficient amount of an extractive agent to provide a relative volatility of 2.0 or greater comprising effective proportions of at least benzoic acid and at least one solvent from the group consisting of adiponitrile, N,N-dimethylacetamide, dimethylformamide, dimethylsulfone, formamide, 1-methyl-2-pyrrolidinone, nitrobenzene, sulfolane, 3-sulfolene, and triethylene-glycol diacetate.

Claim 5

A method for separating benzene from close boiling non-aromatic hydrocarbons which comprises distilling a mixture of benzene and close boiling non-aromatic hydrocarbons in a rectification column in the presence of a sufficient amount of an extractive agent to provide a relative volatility of 2.0 or greater comprising effective proportions of at least benzoic acid and at least one solvent from the group consisting of adiponitrile, N,N-dimethylacetamide, dimethylformamide, dimethylsulfone, formamide, 1-methyl-2-pyrrolidinone, nitrobenzene, sulfolane, 3-sulfolene, and triethylene-glycol diacetate.

Claim 7

A method for separating benzene from close boiling non-aromatic hydrocarbons which comprises distilling a mixture of benzene and close boiling non-aromatic hydrocarbons in a rectification column in the presence of a sufficient amount of an extractive agent to provide a relative volatility of 2.0 or greater comprising effective proportions of maleic anhydride and at least one solvent from the group consisting of acetophenone, adiponitrile, anisole, benzophenone, benzyl acetate, butoxypropanol, butyl benzyl phthalate, diethyl maleate, diethyl oxalate, diethylene glycol, N,N-dimethyl acetamide, N(N,N-dimethylaminopropyl)-2-pyrrolidine, dimethylformamide, dimethylsulfone, dimethylsulfoxide, dipropylene glycol, ethyl acetoacetate, ethylene glycol diacetate, ethylene glycol phenyl ether, formamide, furfural, glycerol triacetate, isobornyl acetate, isophorone, N-isopropyl-2-pyrrolidone, 1-methyl-2-pyrrolidinone, nitrobenzene, 2-nitrotoluene, 3-nitrotoluene, n-octanol, 2,4-pentanedione, phenol, phenyl acetate, phenyl acetic acid, sulfolane, sulfolene, tetrahydorfurfuryl alcohol and triethylene glycol diacetate.

Claim 8

A method for separating benzene from close boiling non-aromatic hydrocarbons which comprises distilling a mixture of benzene and close boiling non-aromatic hydrocarbons in a rectification column in the presence of a sufficient amount of an extractive agent to provide a relative volatility of 2.0 or greater comprising effective proportions of maleic anhydride and at least one solvent from the group consisting of acetophenone, adiponitrile, anisole, benzophenone, benzyl acetate, butoxypropanol, butyl benzyl phthalate, diethyl maleate, diethyl oxalate, diethylene glycol, N,N-dimethyl acetamide, N(N,N-dimethylaminopropyl)-2-pyrrolidine, dimethylformamide, dimethylsulfone, dimethylsulfoxide, dipropylene glycol, ethyl acetoacetate, ethylene glycol diacetate, ethylene glycol phenyl ether, formamide, furfural, glycerol triacetate, isobornyl acetate, isophorone, N-isopropyl-2-pyrrolidone, 1-methyl-2-pyrrolidinone, nitrobenzene, 2-nitrotoluene, 3-nitrotoluene, n-octanol, 2,4-pentanedione, phenol, phenyl acetate, phenyl acetic acid, sulfolane, sulfolene, tetrahydorfurfuryl alcohol and triethylene glycol diacetate.