Ethanol Separation through Ultrasonic Atomization under Controlled Pressure

An aqueous solution of ethanol was ultrasonically atomized, and the mist was recovered to obtain concentrated ethanol solution. The atomization vessel was vacuumed, and the recovery vessel was pressurized for enhancing mist generation and recovery. Batch operation was carried out with and without pressure control, and the results obtained were compared. The amounts of produced and recovered mist increased dramatically upon pressure control. The ethanol concentration in the collected liquid was higher in the presence of ultrasound irradiation than in its absence. It was suggested that production of very fine ethanol-rich droplets was facilitated at reduced pressures, and the recovery was enhanced at elevated pressures.The effect of pressure in the atomization vessel on the amount of mist production and the ethanol concentration in the collected liquid was examined in the presence and absence of ultrasound irradiation. Without ultrasound irradiation, only evaporation would occur. Comparison of the results obtained with and without ultrasound irradiation indicated that the formation of fine droplets affected ethanol separation. The amount of mist collected was 1.4 times the amount of vapor. The ethanol concentration in the collected mist exceeded that in the collected vapor by 5 mol%. The results also suggested that the formation of fine droplets affected the ethanol separation degree by ultrasonic atomization.