Chemical Engineering & Technology

Editors' Choice

Every month, the Editors select two papers referring to current discussions in the scientific, public and economic communities and in view of the potential for further developments. The papers are freely accessible for one month.

Slug Flow of Ionic Liquids in Capillary Microcontactors

June 01, 2013

Liquid-liquid extraction is widely applied for separation tasks in analytical chemistry and biotechnology as well as in pharmaceutical, chemical, petroleum, hydrometallurgical, and food industry. An innovative approach for solvent extraction is the combination of two aspects arisen from the process intensification philosophy – slug-flow microcapillary contactors and ionic liquids (ILs) as clean solvent. Merging the two independent process intensification strategies by implementing IL extraction in slug-flow microcontactors appears synergetic because of the small holdup and efficient mass transfer in slug flow. F. Scheiff et al. investigated the slug flow of disperse IL slugs in continuous organic media in circular microcapillaries. The operating window of the slug-flow microcapillary contactor was ranged in terms of applicable flow rates. Additionally, the intensity of internal circulation was quantified by microscopic particle tracking as a function of superficial velocity, temperature, organic phase, and wall material. In the long run, this research affirms the fluid dynamic feasibility of microcapillary slug-flow extraction with ionic liquids.

F. Scheiff*, A. Holbach, D. W. Agar
Slug Flow of Ionic Liquids in Capillary Microcontactors: Fluid Dynamic Intensification for Solvent Extraction
Chem. Eng. Technol. 2013, 36 (6), 975–984.
DOI: 10.1002/ceat.201200600

 

Generating Gas-Liquid-Liquid Three-Phase Microflows

June 01, 2013

During recent years, micro-structured chemical devices have been described as effective technologies for intensification of chemical engineering processes in numerous applications, such as fine chemicals synthesis, nanomaterials preparation, drug development, and highly efficient separations. The generation of gas-liquid and liquid-liquid two-phase microflows has been quite sufficiently investigated. In addition to the gas-liquid and liquid-liquid two-phase systems, the gas-liquid- liquid three-phase system is also important in the industrial chemical engineering processes. These multiphase systems commonly exist in the organic synthesis reaction and extractive distillation process. G. S. Luo et al. investigated systematically the generation processes of gas-liquid-liquid three-phase microflows in a cross-junction microchannel. Six kinds of three-phase flow patterns were derived from the dispersed characteristics of bubbles and droplets. Mathematic models of average bubble and droplet volumes were established based on the previous knowledge of bubble/droplet size laws in two-phase microflows and the constant bubble/droplet number ratios in three-phase microflows.

K. Wang, Y. Lu, K. Qin, G. Luo*, T. Wang
Generating Gas-Liquid-Liquid Three-Phase Microflows in a Cross-Junction Microchannel Device
Chem. Eng. Technol. 2013, 36 (6), 1047–1060.
DOI: 10.1002/ceat.201200561