Enhancing interfacial mass transfer for high-viscosity fluids: Hydrodynamic and mass transfer by twin-liquid film

The twin-liquid film, which combines wall-bounded film supported by a solid wall and confined-free film through the opening window, has been investigated on a plate with multi-windows. The interaction of wall-bounded film and confined free film has been discussed and the optimal window configurations are obtained with consideration of mass transfer enhancement as well as film stability. The mass transfer rate of the opening window plate is increased by 1.9–2.6 times compared with the solid plate. The acceleration and thinning of the confined-free film are the primary causes of its mass transfer enhancement, with additional contributions from the thinning of the wall-bounded film. To achieve the highest mass transfer efficiency as viscosity increases and diffusion coefficient decreases, it is crucial to maximize the window size without compromising film formation. Twin-liquid films show promising applications in the reactors involving highly viscous fluids such as carbon capture and devolatilization.