Liquid−Liquid Equilibria for Benzene + Cyclohexane +N,N-Dimethylformamide + Potassium Thiocyanate

Experimental liquid-liquid equilibrium (LLE) data were measured for benzene + cyclohexane + N,N-dimethyl-formamide (DMF) + ammonium thiocyanate (NH 4 SCN) at atmospheric pressure and 298.15 K. The experimental data were correlated using the Othmer-Tobias correlation. The selectivity coefficients of DMF + NH 4 SCN for benzene are 2 to 15 in this work. The results revealed that the selectivity coefficients increased with the decreasing of the concentration of benzene in the raffinate and increased with the increasing of the mass fraction of NH 4 SCN in the DMF + NH 4 SCN mixture. Considering the high selectivity for benzene, DMF + NH 4 SCN may be used as a potential extracting solvent for the separation of benzene and cyclohexane.