Dehydration of a dilute acetic acid-water mixture via batch heteroazeotropic distillation

Dehydration via batch heteroazeotropic distillation emerges as a promising technology for the recovery of acetic acid (HAc) from dilute aqueous solutions. In this preliminary work, this process was studied with the aid of Aspen Batch Modeler®, using an acetic acid aqueous solution as the model feed instead of wood vinegar from biorefineries and n-butyl acetate as the azeotropic entrainer. The non-random two liquids (NRTL)-virial Hayden-O'Connell model (HOC) model was chosen to calculate the thermodynamic properties. The response surface methodology with Box-Behnken design was successfully applied to obtain optimum process conditions, providing a dehydrated HAc product from the pot with high purity and recovery.