Mass transfer with chemical reaction in conditions of spontaneous interfacial convection in processes of liquid extraction

Buoyancy-driven pattern formation in reactive immiscible two-layer systems

“…Under the action of gravity the denser liquid sinks into the less dense one inducing a convective pattern which progresses in time. Such chemically driven buoyancy-related patterns have received increasing attention during the last years both from experimental (Sherwood and Wei, 1957;Micheau et al, 1983;Kagan, 1984, 1995;Pons et al, 2000;Ermakov et al, 2001;Karlov et al, 2002) and theoretical (Citri et al, 1990;Pé rezVillar et al, 2000;Bees et al, 2001) point of view. Recently, convective phenomena related to such buoyancy effects due to an exothermic A þB-C neutralization reaction close to an immiscible liquid-liquid interface have been studied experimentally by Eckert and Grahn (1999), Eckert et al (2004), Bratsun et al (2005), Shi et al (2005), Eckert (2006, 2007).…”

Study on reaction kinetics of synthesis of thioether by a visualization technique

“…All of these resulted in a slow mass transfer rate and insignificant Marangoni flow. Ermakov suggested that reaction at the interface would change the phase resistance and break the force balance, resulting in an unstable interface and promote mass-transfer [22]. However, in this study, the reaction rate of thioether synthesis was relatively slow, and the enhancement for turbulence was limited, resulting in insignificant Marangoni flow.…”

Liquid-Liquid Extraction with and without a Chemical Reaction

“…a, as it will be seen in Section 2.3; -The ratio 0 Ka Ka ⋅ ⋅ represents the enhancement factor E; it is higher than 1, sometimes >>1, depending on the physical properties of the system (D A, K 0. a) and the constant of reaction rate; the values of E experimentally determined are useful for the calculation of the concentration of the reactant A at the interface c Ai (Eq.25) needed in further calculations. The intensification of the mass transfer during the chemical reaction was explained here in the frame of the film theory but in fact, the renewal of interface theory could better explain what happens: the interfacial tension depends on the concentration of the transferred substance and as a result, spontaneous interfacial convection is initiated, so a more intensive renovation of the interface and, correspondingly, an increase in the mass transfer coefficient is achieved (Ermakov et al, 2001) Slow reactions The slow reaction can take place in the film but more probably, in the bulk of the solvent phase 2. In Fig.3b, the reaction takes place in the film phase 2.…”