The recovering system (multi-effect evaporation）of butanone-toluene solvent of dewaxing process is simulated with a process simulator.It is shown that good results can be obtained when the complex oil and/or wax mixtures is replaced with a pseudo-single heavy hydrocarbon component in the simulation.The results obtained in this work are comparable to that obtained by the TBP (true boiling point curve）method.One of the possible reasons might be that there is very large difference between molecule properties of the solvent and original oil and/or wax.Compared to the large difference

the difference of molecule properties becomes less important in the oil and/or wax mixture.Therefore

it is possible in the simulation to use a pseudo-single heavy hydrocarbon component instead of complex oil and/or wax mixtures and satisfactory results can be obtained

which can make simulation calculation simple and is favorable for analysis and study of the solvent recovering system.These simulation results have been successfully used in the retrofit of the solvent recovering units in butanone-toluene dewaxing process at a Chinese company for energy saving.