Abstract:

The separation process of acetonitrile-isopropanol binary azeotropic system was simulated by Aspen Plus simulation software, and ethylene glycol was selected as the best extractant. The separation process for recovering acetonitrile and isopropanol by ethylene glycol extractive distillation was optimized and analyzed, and the optimal operating parameters of the extractive distillation process were determined as follows: the extractive distillation process is operated under negative pressure, the optimum number of theoretical plates in the extraction column is 20, with the raw material and extractant fed into the 7th and 18th stages, respectively, the solvent ratio is 1.2, the reflux ratio is 1, the optimum number of theoretical plates in the recovery column is 7, the optimum number of feed stage is 4, and the reflux ratio is 0.35. After optimization, the mass fractions of acetonitrile and isopropanol are 99.25% and 99.39%, respectively. The reboiler duty requirements of the extraction column and the recovery column are 473.01 kW and 493.25 kW, respectively, and the condenser duty requirements of the extraction column and the recovery column are 395.11 kW and 298.22 kW, respectively. High purity acetonitrile and isopropanol products can be obtained by extractive distillation using ethylene glycol as the extractant. The ethylene glycol recovered can be recycled to the extractive distillation process.

Key words: acetonitrile, isopropanol, extractive distillation, ethylene glycol