The solvents for the separation of diphenyl and 4-phenylacetophenone were screened with computer according to the solid-liquid equilibrium equation based on UNIFAC.With the predicted separation factor values and selection principle for feasible solvents

the candidates of better solvents were determined as n-heptane

n-hexane

cyclohexane and diisopropyl ether.The solubility and separation factor of the two solid solutes in n-heptane

n-hexane

cyclohexane

diisopropyl ether and ethanol were measured by static equilibrium method.The average relative deviation between the calculated separation factor and experimental data is 16.73%

indicating that the solid-liquid equilibrium equation based on UNIFAC is suitable to select the separation solvent for solid solute mixtures with similar molecule stereoscopic structures.