Separation of Acetone and Propanal by Extractive Distillation: Experimental Research, Molecular Simulation, and Process Simulation

Acetone and propanal are isomers of carbonyl compounds with similar physical and chemical properties. Their boiling points are 48 and 56.5 °C, respectively, with a small boiling point difference and a relative volatility close to each other, making it difficult to separate them using conventional distillation methods. This study investigates the extraction distillation separation of a raw material system with a mass fraction composition of 10% propanal and 90% acetone, aiming to obtain products with a mass fraction of over 99.5% for both propanal and acetone. The infinite dilution activity coefficient method was first used to screen the extractant, which was then validated through extraction distillation experiments. Among the seven candidate extractants, ethylene glycol (EG) was selected as the most suitable one. The separation mechanism of extraction distillation was analyzed by using COSMO-SAC and Gaussian software, and Aspen software was finally employed to simulate the extraction distillation separation process. This work can provide a theoretical basis and data support for the industrial separation of propanal–acetone mixtures.