The Research Of A New Style Extraction Process In Droplet-film Alternative Flow

For the liquid-liquid extraction process, the flowing pattern of the dispersed phase in continuous phase has important influence on mass transfer efficiency. Primary experiment revealed that the mass transfer process of 30%TBP(kerosene)-acetic acid-water was improved dramatically when dispersed phase realized droplet-film alternate flowing pattern using a new style hybrid structured packing. In this paper, further study of mass transfer performances by different systems in a hybrid structured packing has been done.Firstly, the mass transfer performance of the high interfacial tension toluene-acetone-water and the middling interfacial tension butyl acetate-acetone-water in a new hybrid structured packing was measured by experiment. Experiment was carried out in a square glass extraction tower. The apparent height of mass transfer unit (HTU) of different systems in different packing was tested. Result showed that the mass transfer performance of a novel hybrid structured packing was 6%~22% higher than that of non-hybrid packing in middling interfacial tension; but the result of the high interfacial tension was opposite.Secondly, mass transfer and flow pattern of droplet-film alternate flow were simulated using the computational fluid dynamic method. The toluene/acetone/water and butyl acetate/acetone/water were selected as the systems. The simulation of the flow process agrees well with the experimental phenomena; and in the same hybrid structured packing, the mass transfer efficiency of different systems demonstrate the higher the interfacial system, the lower the mass transfer efficiency.