Separation Of Cyclohexane-Tetrahydrofuran By Batch Extractive Distillation

Cyclohexane and THF are very important intermediate in organic synthesis. They are widely used in covering material, adhesive and so on. But cyclohexane and THF having the small relative volatility can not be separated by conventional distillation. So this paper discusses the batch extractive distillation using DMF as the extractive solvent to separate the mixture.Firstly, the vapor-liquid equilibrium curve of THF-cyclohexane was determined by combination of calculation and experimented data. Then select the extractive solvent of the binary mixture using group contribution method and validate the effect of the solvent though the vapor-liquid equilibrium experiment. The feasible solvent ratio is also determined. The results of experiment showed that DMF can augment the relative volatility, the solvent ratio which is 1:1 is the feasible solvent ratio.Secondly, the small scale batch extractive distillation was done to separate the binary mixture. In these experiments, the solvent consumption and the separate degree of the extractive distillation were compared during the different concentration raw material. The effect of the operation parameter solvent flow rate was studied. The result of the experiment showed that the feasible solvent ratio is 1:1.Thirdly, this paper calculated this batch extractive distillation process, and the equilibrium mode describing BED was established, adopting the modified two-point implicit integration method to calculate, programming though Fortran 90. The results of the program showed the convergence and stability of the calculated method were good. And the simulated results and the above experiment date show good agreement. It also indicate the calculated mode is reliable.