화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.60, No.4, 1532-1541, 2021
Utilizing Low-Voltage Pulsed Electric Fields for Mass Transfer Intensification of Drops in Liquid-Liquid Extraction
Low-voltage pulsed electric fields, corresponding to field strengths of 2-16 V/cm, were utilized for mass transfer intensification of drops in a liquid-liquid extraction process. The chemical system of kerosene-acetic acid-water was used in which mass transfer resistance lies mainly in the kerosene phase. The applied frequencies were within 100-1000 Hz. In a hydrodynamic study, the circulating state of drops was confirmed based on different criteria and their terminal velocity precisely followed the Grace model. A mass transfer study of drops, on the other hand, revealed the strong impact of a pulsed electric field with the average and maximum enhancements of 30.3 and 70.5%. This can be attributed to the interfacial instability due to switching poles in the pulsed electric field. An optimum frequency of about 300 Hz corresponded to the applied voltages. Applying a direct electric field also had desired effects but in a lower extent. The provided mass transfer coefficient data were reproduced based on the Kumar and Hartland correlation together with a developed correlation of the enhancement factor in terms of dimensionless field strength, frequency, and the drops' Reynolds number. The maximum deviation between experimental and predicted Sherwood numbers was +/- 5%.