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Abstract: A toluene droplet rising in a continuous aqueous phase is studied both experimentally and numerically. The experiments have been performed in a small scale, high-speed measuring unit with a high magnification device to image the process in all details. Numerical simulations are performed with the aid of the level set method implemented in the commercial CFD tool COMSOL Multiphysics 3.3a by COMSOL AB. A new technique for quantitative comparison of experimental and numerical results with respect to the droplet shape is presented. Both terminal velocity and droplet shape in experiments and simulations are found to be in excellent agreement. Based on the experimental and numerical data obtained, an improvement of an existing terminal velocity correlation is suggested. The adjusted correlation can be used for the design and optimisation of liquid–liquid extraction units. [Copyright &y& Elsevier]

Abstract: Process intensification of liquid–liquid extraction columns using reactive extraction systems and population balance modelling approaches are discussed. As a means of process intensification, bulk organic solvents could be replaced by chemically reactive organic phases in order to enhance the extraction efficiency and selectivity. Moreover, extraction of speciality materials could be achieved by using either ionic liquids or solvent phases containing a controlled quantity of surfactants. For deep insight and hence better performance of liquid–liquid extraction columns, population balance modelling approaches can be utilized for process intensification, since the model parameter estimation is possible in small lab-scale devices instead of pilot plant experiments as it is state of the art. A significantly reduced time-to-market period and savings in costs will result. A further improvement can be achieved when the population balance model is coupled to computational fluid dynamics (CFD) where detailed flow fields and turbulent energy dissipation could be obtained. This will foster high-precision engineering, especially with large-scale industrial units. [Copyright &y& Elsevier]

The mass transfer into droplets in metal extraction is investigated in the system ZnSO4–H2SO4/di(2ethylhexyl)phosphoric acid in isododecane. Results of equilibrium measurements and stirred cell experiments are described in a mathematical model based on gradients of chemical potential. Concentration profiles measured with Laser Induced Fluorescence technology were calculated with the Maxwell–Stefan equations. Diffusion coefficients were estimated using the Wilke and Chang equation. Additional eddy diffusion coefficients measured in single droplet experiments in a venturi tube are described with different models known from literature. Whereas equilibria and mass transfer into droplets in stagnant conditions can be calculated with good agreement with the experimental results, none of the known models describes eddy diffusion in reactive extraction occurring in free moving droplets sufficiently well over a broad concentration range. [Copyright &y& Elsevier]

• Processing industrial leaching solutions from spent lithium-ion batteries. • Separation of manganese with saponified D2EHPA. • Influence of saponification degree on extraction yield and selectivity. • Equilibrium study for two extraction stages. • Overall extraction yield of manganese is 98.7%. Solvent extraction is used for the selective extraction of manganese from an industrial leaching solution based on active material from spent lithium-ion batteries. As solvent 100 g L−1 di-(2-ethylhexyl) phosphoric acid (D2EHPA) diluted in Isopar L and an addition of 5 vol% tributyl phosphate is used. D2EHPA is well studied for the separation of manganese from cobalt and nickel but no data can be found on the influence of saponification. The influence of the saponification degree on the extraction yield and selectivity is investigated for two extraction stages. An overall extraction yield of 98.7% is achieved. 40% saponified D2EHPA for the first and 20% for the second stage at a phase ratio of 2.33 shows the best performance in terms of extraction yield and selectivity. The saponification influences the pH shift during the extraction from initial 2.8 to 3.4. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: The thermo-sensitive poly(N-isopropylacrylamide) (poly(NIPAAm)) hydrogel is synthesized by free radical polymerization. As a model solute in the study of drug loading and release kinetics with hydrogels, the bovine serum albumin (BSA) protein was used to measure the volume changes and the release kinetics by thermal deswelling. Experiments are performed at different temperatures around the low critical solution temperature (LCST). The effect of the release temperature upon polymer characteristics and release properties was investigated. The BSA release coupled with shrinking of the hydrogel particles was modelled with a bi-dimensional diffusion model with moving boundary conditions. The influence of the variable diffusion coefficient is observed and leaded to better description of the kinetic curve in the case of important deformation around the LCST. A good correlation between experimental and calculated data was obtained. [Copyright &y& Elsevier]