Thirty compounds including salts, saccharides, and alkalies have been investigated as possible salting-out agents to recover (acetone + butanol + ethanol) (ABE) from a prefractionator. The most promising salt is potassium carbonate. The mechanisms of salting-out by potassium carbonate are summarized as hydration and hydrogen-bond breaking. The thermodynamic study of salting-out by potassium carbonate has been investigated and shows that the salting-out process is endothermic and a process of entropy increment. The extractant of saturated potassium carbonate solution should be double that of the sketchy ABE solution. When the salting-out process is performed at 333.15 K instead of 298.15 K, equilibrium time is shortened from 9 to 3 mm. Energy demand in an industrial application shows that salting-out produces 25.13 %, even 35.42 % less energy consumption than that of the conventional distillation process.