Study On Sodium Thiocyanate And N,N-dimethylformamide Extraction Separation Benzene From Cyclohexane

Benzene and cyclohexane separation is the typical representative and relatively difficultseparation of aromatics/alkanes. Cyclohexane is prepared by hydrogenation of benzenewhich make separating Benzene and cyclohexane more essential. Yet Benzene andcyclohexane which are all similar in chemical structure and property can form azeotrope andcan not be separated by simple distillation. Extractive distillation and azeotropic distillationare two usual methods for separating benzene and cyclohexane in industry, however its highexpenses, complex process, high energy consumption. It is eager to find a kind of effectivemethod to separate benzene and cyclohexane mixture in industry.Extraction is a viable alternative to the conventional techniques both from economicaland technical points of view. Extraction was chose to separate benzene and cyclohexane inthis subject. In this work, it is found that NaSCN+DMF can not only separate benzene fromcyclohexane, but also the solubility is better than KSCN. Sodium thiocyanate dissolved inDMF, is found to be a excellent extractant, because of the high selective and economical.Toward this aim, LLE data for quarternary systems of benzene+cyclohexane+DMF+sodium thiocyanate were measured at303.15K and atmospheric pressure.It was found thatthe selectivity coefficients of DMF+NaSCN for benzene ranged from2.45to11.99. Theresults revealed that the selectivity coefficients increased with the decreasing of theconcentration of benzene in the raffinate, and increased with the increasing of the massfraction of NaSCN in DMF+NaSCN mixture. The results shown that the selectivitycoefficients increased with the decreasing of the concentration of benzene in the raffinate,and increased with the increasing of the mass fraction of NaSCN in DMF+NaSCN mixture.The NRTL equation and the Wilson model were used to correlate the experimentalresults and to calculate the phase composition of the studied mixture. From the calculateresult, the NRTL equation is better to correlate the benzene+cyclohexane+DMF+NaSCNquaternary system. ChemCAD was used to simulate how the flow ratio, constituent ofmixture and extraction reagent affect the separation effect. The results show that this kind ofextraction reagent has a good separation effect on benzene and cyclohexane.According to the properties research of DMF+NaSCN, the compound solvent has ahigher electrical conductivity in30℃. In view of this, further studies the electrochemical performance of DMF+NaSCN. DMF as a kind of protons polarity solvent, with excellentsolubility property, low viscosity and low-K， widely used in many regions. So we considerDMF as a good electrolyte materials. We prepared the different concentrations solution DMF+NaSCN, and discuss the organic compound solvent as electrolyte electrochemical behaviorof the capacitors.This thesis using chemical oxidation method to prepared the polymers of polyanilineand polyaniline/carbon composite materials. Compared with1.0mol/L LiPF6/(EC+DMC)organic electrolyte and composite solution of DMF+NaSCN electrolyte, the experimentalresults show that, the composite solution DMF+NaSCN also has electrochemicalperformance. According To This, DMF+NaSCN electrolyte will has great potential becauseits low cost, simple preparation, have advantages of the electrochemical performance.