Gas–Liquid Slug Flow Studies in Microreactors: Effect of Nanoparticle Addition on Flow Pattern and Pressure Drop

Colloidal suspensions of nanoparticles (e.g., metals and oxides) have been considered as a promising working fluid in microreactors for achieving significant process intensification. Existing examples include their uses microflow catalysts enhancing the reaction efficiency, or additives to mix with base (i.e., form so-called nanofluids) heat/mass transfer Thus, hydrodynamic characterization such suspension flow is high importance rational design operation system. In this work, experiments conducted investigate pattern pressure drop characteristics under slug between N 2 gas colloidal presence TiO Al O 3 through polytetrafluoroethylene (PTFE) capillary microreactors. The consisted water its mixture ethylene glycol. nanoparticle addition was characterized by lubricating liquid film around bubbles, contrast absence case -water flow. This shows that has changed wall wetting property be more hydrophilic. Furthermore, measured -nanoparticle well described model Kreutzer et al. (AIChE J 51(9):2428–2440, 2005) at Reynolds numbers ca. above 100 better predicted Warnier (Microfluidics Nanofluidics 8(1):33–45, 2010) lower given consideration effect thickness bubble velocity conditions latter model. Therefore, employed can stable pseudo single phase proper properties viscosity density) when it comes estimation.