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Parallel flow of immiscible liquids in a microreactor: modeling and experimental study

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Abstract

Two-phase parallel flow can be utilized in microreactor engineering for performing reactions and extractions, and also for achieving efficient phase separation at the exit of the microreactor. Typical laminar flow at the microscale allows two phases to flow in parallel without mixing, allowing highly controlled conditions for a specific chemical process. Since the liquid with the higher viscosity has a tendency to occupy a larger fraction of the microchannel, the position of the interface can be controlled through the adjustment of flow rates. The prediction of the position of the interface is important for microreactor design and operation and requires the solution of the governing equations of fluid mechanics. In this work, the theoretical description for two-phase parallel flow, based on the Navier–Stokes equations in three dimensions was expressed with a mathematical model and validated with experimental observations. The movement of the interface was achieved through the adjustment of fluid properties according to the position of the central streamlines. The predicted position of the interface was in good agreement with experimental data. A correlation for the flow rate ratio required for positioning the interface in the middle of the channel for various viscosity ratios was proposed, as well as a correlation for the prediction of the parallel to slug transition for a water/n-hexane system.

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Abbreviations

Bo :

Bond number (–)

Ca :

Capillary number (–)

D h :

Hydraulic diameter (m)

g :

Standard gravity (m/s2)

H :

Microchannel height (m)

Kn :

Knudsen number (–)

L :

Microchannel length (m)

p :

Pressure (Pa)

R 1 :

Radius of curvature (m)

R 2 :

Radius of curvature (m)

Re :

Reynolds number (–)

Re c :

Critical Reynolds number (–)

t :

Time (s)

u :

Velocity in the x direction (m/s)

uvw :

Overall flow field (m/s)

v :

Velocity in the y direction (m/s)

w :

Velocity in the z direction (m/s)

\( \bar{w}_{\text{h}} \) :

Average velocity of n-hexane at the inlet to the central channel (m/s)

\( \bar{w}_{\text{w}} \) :

Average velocity of water at the inlet to the central channel (m/s)

W :

Microchannel width (m)

We :

Weber number (–)

γ:

Interfacial tension (N/m)

μ :

Viscosity (Pa s)

ρ :

Density (kg/m3)

τ :

Artificial compressibility (s m/kg)

Φ 1 :

Flow rate of one phase (m3/s)

Φ 2 :

Flow rate of the other phase (m3/s)

References

  • Aljbour S, Yamada H, Tagawa T (2009) Simultaneous reaction–separation in a microchannel reactor with the aid of a guideline structure. Int J Chem Biol Eng 2:220–223

    Google Scholar 

  • Andreson JD Jr (1995) Computational fluid dynamics—the basics with applications. McGraw-Hill, New York

    Google Scholar 

  • Cheng P, Wu HY (2006) Mesoscale and microscale phase-change heat transfer. Adv Heat Transf 39:461–563

    Article  Google Scholar 

  • Galambos P, Forster F (1998) An optical micro-fluidic viscometer. International Mechanical Engineering Congress and Exposition, Anaheim. http://www.mendeley.com/research/optical-microfluidic-viscometer/

    Google Scholar 

  • Guillot P, Colin A (2005) Stability of parallel flows in a microchannel after a T junction. Phys Rev E 72:066301

    Article  Google Scholar 

  • Guillot P, Moulin T, Kotitz R, Guirardel M, Dodge A, Joanicot M, Colin A, Bruneau CH, Colin T (2008) Towards a continuous microfluidic rheometer. Microfluid Nanofluid 5:619–630

    Google Scholar 

  • Hibara A, Tokeshi M, Uchiyama K, Hisamoto H, Kitamori T (2001) Integrated multilayer flow system on a microchip. Anal Sci 17:89–93

    Article  Google Scholar 

  • Hitt DL, Macken N (2004) A simplified model for determining interfacial position in convergent microchannel flows. J Fluids Eng 126:758–768

    Article  Google Scholar 

  • Kashid M, Kiwi-Minsker L (2011) Quantitative prediction of flow patterns in liquid–liquid flow in micro-capillaries. Chem Eng Process. doi:10.1016/j.cep.2011.07.003

  • Kashid MN, Renken A, Kiwi-Minsker L (2011) Influence of flow regime on mass transfer in different types of microchannels. Ind Eng Chem Res 50:6906–6914

    Article  Google Scholar 

  • Lu Y, Xia Y, Luo G (2011) Phase separation of parallel laminar flow for aqueous two phase systems in branched microchannel. Microfluid Nanofluid 10:1079–1086

    Article  Google Scholar 

  • Münchow G, Hardt S, Kutter JP, Drese KS (2007) Electrophoretic partitioning of proteins in two-phase microflows. Lab Chip 7:98–102

    Article  Google Scholar 

  • Pohar A, Plazl I (2008) Laminar to turbulent transition and heat transfer in a microreactor: mathematical modeling and experiments. Ind Eng Chem Res 47:7447–7455

    Article  Google Scholar 

  • Pohar A, Plazl I, Žnidaršič Plazl P (2009) Lipase-catalyzed synthesis of isoamyl acetate in an ionic liquid/n-heptane two-phase system at the microreactor scale. Lab Chip 9:3385–3390

    Article  Google Scholar 

  • Tamamidis P, Zhang G, Assanis DN (1996) Comparison of pressure-based and artificial compressibility methods for solving 3D steady incompressible viscous flows. J Comput Phys 124:1–13

    Article  MATH  Google Scholar 

  • Zhao Y, Chen G, Yuan Q (2006) Liquid–liquid two-phase flow patterns in a rectangular microchannel. AIChE J 52:4052–4060

    Article  Google Scholar 

  • Žnidaršič-Plazl P, Plazl I (2007) Steroid extraction in a microchannel system—mathematical modeling and experiments. Lab Chip 7:883–889

    Article  Google Scholar 

  • Žnidaršič-Plazl P, Plazl I (2009) Modelling and experimental studies on lipase-catalyzed isoamyl acetate synthesis in a microreactor. Process Biochem 44:1115–1121

    Article  Google Scholar 

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Correspondence to Igor Plazl.

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Pohar, A., Lakner, M. & Plazl, I. Parallel flow of immiscible liquids in a microreactor: modeling and experimental study. Microfluid Nanofluid 12, 307–316 (2012). https://doi.org/10.1007/s10404-011-0873-7

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  • DOI: https://doi.org/10.1007/s10404-011-0873-7

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