Comparison of COSMO-SAC Model and DFT Quantum Chemical Model in Molecular Design of IL Extractant

摘要

ILs agents with better extraction efficiency for desulfurization were screened by simulation in this paper.The COSMO-SAC model and the density functional theory(DFT)were used to select the prospective solvents from a wide variety of ionic liquids suitable for extractive distillation.The COSMO-SAC model and the density functional theory(DFT)were used to study the inconsistencies of the efficiency of extractive separation during the simulation.Six ILs solvents with better extraction efficiency were screened out by the COSMO-SAC model.And the six kinds of ionic liquids based on the extraction efficiency order determined by the COSMO-SAC model were reordered based on the DFT model.The results showed that the order of desulfurization efficiency based on the two kinds of models was different.Experiments were carried out to verify the accuracy of the two sequences.The order of the above six ILs related with the extractive desulfurization efficiency was studied by experimental researching.The results show that the extraction efficiency sequence of the six ILs obtained by the experiment is consistent with the order of simulation results based on the DFT model.The difference between the COSMO-SAC model and the DFT model was analyzed and interpreted from the calculation principle aspect at the end of this paper.