Intensified liquid-liquid extractions by continuous flows in small channels

Separations underpin materials processing and purification in many industrial sectors. Solvent extractions are particularly widespread because of their efficiency, selectivity and versatility in diverse application areas. Intensified continuous separations in small channels have emerged as a transformative solution for the transition to sustainable extractions, while they enable the industrial uptake of novel non-petroleum based solvents. The paper discusses recent work on intensified extractions in small channels using novel solvents such as ionic liquids and aqueous biphasic systems. Results on the two-phase hydrodynamics and their effects on extraction efficiency and mass transfer are presented for the separations of metals and of biomolecules. In the future, integration of sensors for in-line measurements coupled with predictive models will enable dynamic and adaptive process operations for continuous small channel extractions, forming the basis for development of digital twins for separations.