Droplets Breakage And Its Effect On Liquid-Liquid Mass Transfer

Droplets breakage has an important impact on mass transfer efficiency for liquid-liquid extraction process. Fundamental research on droplets breakage phenomena is of great importance for the development of new liquid-liquid extraction equipment. For this reason, vibration and gas disturbance, which can strengthen the droplets broken process, were investigated in this paper.Based on our previous work, a novel extraction column, Liquid-Liquid extraction reciprocating structured packing column, was developed. Mass transfer performance of this equipment was tested in aΦ50 mm packing extraction column. 30% TBP (kerosene)-acetic acid-water was selected as the test system. The apparent height of mass transfer unit (HTU), holdup of dispersed phase and flooding holdup were measured with different operation conditions. Results show that the HTU of Liquid-Liquid extraction reciprocating structured packing column is lower than Reciprocating sieve plate column by 18% averagely, the holdups of dispersed phase and flooding holdup are higher than Reciprocating sieve plate column, by 30% and 20%, respectively.For the phenomenon that gas disturbance can strengthen droplets broken process, a new type of Gas-Liquid-Liquid extraction equipment was developed in this paper. Bubbles breakage in structured packing column was observed by taking photos. The bubble diameter is 2~3mm distributing uniformly. It is much smaller than that in plate column, which is 6~7mm. The mass transfer efficiency of medium interfacial tension system was researched in this equipment. Results show that the HTU of gas disturbance structured packing column is lower than no gas disturbance structured packing column by 15%. In addition, the mass transfer efficiency of high interfacial tension system was tested. Anthraquinone working solution was selected as the test system. Results show that the HTU of gas disturbance structured packing extraction column is lower than sieve plate extraction column by 65% ,while the holdups of dispersed phase is higher than sieve plate column by 25% under the same operation conditions.