Process intensification in reactive extraction by phase inversion in gas/liquid/liquid microdispersion system

Reactive extraction is widely applied to wastewater treatment, hydrometallurgy, and other industries. In this study, process intensification in reactive extraction of formic acid at an aqueous-to-oil phase ratio of 75:1 was conducted, by developing microdispersed liquid/liquid and gas/liquid/liquid systems with phase inversion. In two of the gas/liquid/liquid modes, the Murphree efficiency reached 90% within 2.0 s, which was below 28% within 28.3 s when it was carried out with millimeter-dispersed emulsion systems. The effects of phase inversion and the addition of microbubbles were systematically studied. Uniform correlations were developed to investigate the intensification effect of microbubbles in mass transfer during the formation stage in six gas/liquid/liquid dispersion methods and mass transfer during the flowing stage in four (G + O)/W emulsion systems. The most effective modes were recommended by studying process intensification fundamentals in different gas/liquid/liquid modes. This study provided simple and effective methods for process intensification of reactive extraction.