Investigation of the efficiency of mixed solvents for thorough elimination of thiophens from benzene and toluene by extractive rectification

Journal Article · Thu Jan 01 04:00:00 EST 1981 · Coke Chem. USSR (Engl. Transl.); (United States)

OSTI ID:6931325

Miroshnichenko, A A; Fedosyuk, L G

The efficiency of extractive rectification (ER) for removing thiophens from C/sub 6/-C/sub 7/ aromatic hydrocarbons is determined by the relative volatilities of the components being separated (..cap alpha..) depending on the form of the extractant. Therefore, the object of the current investigation has been to find more effective separating agents for the thorough elimination of thiophen and 2- and 3-methylthiophens from benzene and toluene by the ER method. First a study was made of the selectivity (..beta..) of solvents under liquid/liquid equilibrium conditions in systems including thiophen, benzene, toluene, polar solvent and n-decane. The results from the investigation of 30 systems with different solvents showed the presence of functionally selective classes of extracting agents in which the selectivity is determined by the free unsubstituted groups of the solvent. The conclusions relating to the removal of thiophen from benzene are applicable equally for purifying toluene, for which the relation volatility for the methylthiophens in the presence of mixed solvents is as high as or for benzene and thiophen. Therefore mixed solvents may be recommended for removing thiophen or methylthiophens and producing high purity aromatic hydrocarbons with nondestructive separation of the organic sulfur compounds. From data on liquid/liquid and liquid-vapor equilibrium in systems including nonaqueous and aqueous simple and mixed solvents, benzene, toluene, thiophen or 2- and 3-methyl thiophens it has been established that there are functionally selective classes of solvents for the aromatic hydrocarbon-thiophen systems. The most selective mixed solvents for the extractive rectification of the systems thiophen-benzene, methylthiophen-toluene are NMP-ethylenecarbamide-water and pyrrolidone-2-ethylenecarbamide-water, the latter being preferred.

• OSTI ID: 6931325
• Journal Information: Coke Chem. USSR (Engl. Transl.); (United States), Journal Name: Coke Chem. USSR (Engl. Transl.); (United States) Vol. 9; ISSN COKCA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010500* -- Coal
Lignite
& Peat-- Products & By-Products
AROMATICS
BENZENE
COAL TAR
DISTILLATION
EQUILIBRIUM
FLUIDS
GASES
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
LIQUIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OTHER ORGANIC COMPOUNDS
PROCESSING
PURIFICATION
REMOVAL
SEPARATION PROCESSES
TAR
THERMODYNAMICS
THIOPHENE
TOLUENE
VAPORS
VOLATILITY