Influence of the plate-type continuous micro-separator dimensions on the efficiency of demulsification of oil-in-water emulsion
| Autor: | Jean-François Portha, Thibault Roques-Carmes, Philippe Marchal, Hubert Monnier, Laurent Falk |
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| Přispěvatelé: | Laboratoire Réactions et Génie des Procédés (LRGP), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2014 |
| Předmět: |
Coalescence (physics)
Buoyancy Chemistry General Chemical Engineering Aqueous two-phase system Analytical chemistry Separator (oil production) 02 engineering and technology General Chemistry engineering.material 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 6. Clean water 0104 chemical sciences Volumetric flow rate Physics::Fluid Dynamics Creaming Phase (matter) Emulsion engineering [CHIM]Chemical Sciences Composite material 0210 nano-technology |
| Zdroj: | Chemical Engineering Research and Design Chemical Engineering Research and Design, Elsevier, 2014, 92 (11), pp.2758-2769. ⟨10.1016/j.cherd.2014.02.001⟩ |
| ISSN: | 0263-8762 |
| DOI: | 10.1016/j.cherd.2014.02.001 |
| Popis: | International audience; The objective of this article is to find the optimal dimensions of rectangular plate-type micro-separators in order to enhance the continuous separation of immiscible liquids. The main structure of the separators contains two plates: a hydrophobic (PTFE) upper plate and a hydrophilic (stainless steel) bottom plate which formed the contact surfaces for the fluids in the channel. The devices have two outlets, one for the aqueous phase and the other for the organic phase enabling the continuous separation and withdrawal of the separated phases. Demulsification has been carried out using Shellsol/water emulsion in the presence of a non-ionic surfactant (Teen 80). The separation efficiency is investigated as a function of micro-separator sizes, channel depths, flow rates and plate configurations. The major parameter that controls the destabilization mechanism is the ratio between the droplet size and the channel depth. When the size of the dispersed droplets remains smaller than the height of the separator (channel depths: 25-100 mu m), creaming is the main demulsification mechanism. Creaming refers to the migration of the dispersed phase of an emulsion, under the influence of buoyancy. The particles float upwards and rise to the top due to the difference in the densities of the particles and the medium. The separation efficiency depends mainly on the residence time of the liquid/liquid mixture in the device regardless of the separator dimensions and channel heights. The separation rate is limited by the removal of the cream layer, formed at the top of the upper plate, from the separator. When the size of the dispersed droplets is larger than the depth of the separator (channel height of 9 pm), the separation performance and mechanism become different. The coalescence of the dispersed droplets occurs by passing through the device. The comparison of the data corresponding to creaming and coalescence phenomena emphasizes that the coalescence greatly enhance and accelerate the separation action. The phase separation in the micro-coalescer takes place considerably faster than in the micro-separators. |
| Databáze: | OpenAIRE |
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