The group separation of low temperature coal tar (LTCT) is important for its effective utilization. With n-dodecane

toluene and phenol as model compounds

the liquid-liquid-equilibrium (LLE) of alkane-aromatics-phenol ternary system in LTCT were obtained by experimental method and Aspen Plus simulation. The LLE of typical ternary systems during separation of the mixture by N

N-dimethylformamide (DMF) water solution were also simulated. The results show that the ternary phase diagram simulated by Aspen Plus through UNIF-LL model fit well with experimental data. Toluene as a cosolvent promotes n-dodecane-toluene-phenol to be a homogeneous system. According to the solubility difference of n-dodecane

toluene and phenol in DMF and with the Hansen solubility parameters theory

n-dodecane and toluene can be separated successively from their homogeneous mixture by DMF in which different content of water were added to adjust the polarity of solvent. Based on the optimization of extraction temperature

solvent/oil ratio and water content in solvent

n-dodecane with 93.2% purity was separated by one stage extraction with DMF

and after phase separation

toluene with 93.4% purity was obtained by adding water weighted 30% of DMF to the extract phase at 303K

1.5 solvent/oil ratio.