Background Membrane emulsification (ME) is an attractive membrane process to produce various kind of simple or multiple emulsions. The membrane utilized in ME process should have high dispersed phase flux, narrow pore size distribution and excellent antifouling property. Methods This work proposed a novel near-field electrospun (NFES) poly(tetrafluoroethylene) (PTFE) membranes with ordered rectangular pore geometry. Compared with other membranes, the order pore geometry of NFES PTFE membrane was helpful to obtain a more homogeneous and more stable water-in-oil (W/O) emulsion. Significant findings The droplet size was simply controlled by the NFES PTFE membrane pore size. And NFES PTFE membrane was more conducive to the formation of droplets with narrow droplet size distribution because of its unique straight rectangular membrane pore geometry. In addition, W/O emulsion droplet size be regulated in coordination with operating parameters and phase parameters. Results indicated that a smaller rectangular pore area of PTFE membrane would lead to a smaller droplet size. Introducing of shear stress in the continuous phase was contributed to the generation of monodisperse droplets. When the emulsifier (Span 80) content was 1wt%, the smallest droplet size (∼103.6 nm) was obtained.
As emerging green solvents, ionic liquids (ILs) have promising applications in many fields. However, its long reaction time and high price restrict its industrial application. The main reason for this is due to the generation of droplets during the synthesis reaction. Aiming at the process intensification of the 1-methylimidazole (MIM)-based ILs, this paper has studied the evolution behavior of the droplets during its synthesis according to droplet breakage theory. The results show that the droplet size distribution (DSD) and its number density are closely related to the reaction progress. By comparing the Kolmogoroff microscale and droplet size, the synthesis process can be divided into Reaction stage I, when the conversion of MIM is below 60%, and Reaction stage II, when the conversion of MIM is beyond 60%. High stirring speed and temperature increase have been put forward for each stage. The reaction time can be effectively reduced by 43.93%, which is instructive in improving the production efficiency of [BMIM]Br.
Yang Li,Jieliang Chen,Long Meng,Shirong Chen,Boren Tan,Tao Qi,Yong Wang
The pulse disc and doughnut columns (PDDC) require high energy input when dealing with systems where the dispersed phase is difficult to break, which limits its application. To address this, a novel extraction column, pulsed sieve − disc and doughnut column (PSDDC) was designed. The hydrodynamics and extraction performance in the PSDDC were investigated systematically using neodymium-iron-boron (NdFeB) magnet scraps acid leachate–PC-88A extractant system. The results indicated that inducing sieve plates effectively reduced droplet size at a mild pulse intensity. Furthermore, compared with the required pulse intensity of 1.5 cm/s to shift operation zone from mixer-settler zone to emulsion zone in PDDC, PSDDC only required 1.0 cm/s. In the mixer-settler zone, the dispersed phase holdup ( x d ) values were comparable in both columns, while in the emulsion zone the x d values in PSDDC were higher than those in PDDC. At a medium pulse intensity of 1.5 cm/s, the extraction performance of rare earth elements (REEs) in the PSDDC was enhanced, with an extraction efficiency of 65.19 %, representing a 6-fold increase over the PDDC. Additionally, new correlations were established for the Sauter mean droplet size ( d 32 ), x d and mass transfer coefficients of dispersed phase ( K od ) in PSDDC, yielding average relative residual errors ( AARE s) of 9.43 %, 10.96 %, and 10.04 %, respectively. Briefly, compared with PDDC, PSDDC exhibited excellent extraction performance for REEs in the NdFeB acid leachate–PC-88A system.
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