Optimization of Flow in Microbial Fuel Cells: An Investigation into Promoting Micro-Mixer Efficiency with Obstacle

Chin-Tsan Wang; Cheng Kuang Shaw; Tzu-Yang Hu

doi:10.6180/jase.2011.14.1.04

Optimization of Flow in Microbial Fuel Cells: An Investigation into Promoting Micro-Mixer Efficiency with Obstacle

Chin-Tsan Wang This email address is being protected from spambots. You need JavaScript enabled to view it.¹, Cheng Kuang Shaw² and Tzu-Yang Hu¹

¹Department of Mechanical and Electromechanical Engineering, National I-Lan University, I-Lan, Taiwan 260, R.O.C.
²Department of Mechanical and Aerospace Engineering, University of California: Los Angeles

Received: June 16, 2009
Accepted: August 5, 2010
Publication Date: March 1, 2011

Download Citation: ||https://doi.org/10.6180/jase.2011.14.1.04

ABSTRACT

An important obstacle to overcome in the advancement of microbial fuel cell (MFC) technology is to improve the efficiency of the micro-channel and micro-mixer components in a MFC system. Through the use of a commercial computational fluid dynamics (CFD) simulator, this project analyzed three passive Y-type micro-mixer designs and collected data pertaining to velocity, pressure drop, and performance flow efficiency. Various factors considered in this study include inlet aspect ratios and varying inlet Reynolds ratios. When the micro-mixers were investigated, the introduction of mixing cylinders inside the micro-mixer increases mixing efficiency but also raises the pressure drop. In addition, the flow mixing would be enhanced with a lower Aspect ratio and a larger inlet Reynolds ratio. The side wall effect and shear stress would offer a positive effect on flow mixing. The concept of the cylinders embedded in the flow channel would be applied to MFCs for improvement of power performance.

Keywords: Passive Micro Mixer, Cylinder, Microbial Fuel Cell (MFC)

REFERENCES

[1] Dyer, C.-K., “Fuel Cells for Portable Applications,” J Power Sources, Vol. 106, pp. 3134 (2002).
[2] Chiao, M., Lam, K.-B. and Lin, L., “Micromachined Microbial Fuel Cells,” 2003 IEEE The Sixteenth Annual International Conference on Micro Electro Mechanical Systems, Kyoto, pp. 383386 (2003).
[3] Justin, G.-A., Zhang, Y., Sun, M. and Sclabassi, R., “Biofuel Cells: A Possible Power Source for Implantable Electronic Devices,” 2004 Proceedings of the 26th Annual International Conference of the IEEE EMBS, California, pp. 40964099 (2004).
[4] Lam, K.-B., Johnson, E.-A., Chiao, M. and Lin, L., “A MEMS Photosynthetic Electrochemical Cell Powered by Subcellular Plant Photosystems,” J Microelectromechanical S, Vol. 15, pp. 12431250 (2006).
[5] Chew, Y.-T., Xia, H.-M. and Shu, C., “Techniques to Enhance Fluid Micro-Mixing and Chaotic Micromixers,” Modern Physics Letters B, Vol. 19, pp. 1567 1570 (2005).
[6] Deshmukh, A.-A., Liepmann, D. and Pisano, A.-P., “Continous Micromixer with Pulsatile Micropumps,” IEEE Workshop on Solid-State Sensors and Actuators, pp. 7376 (2000).
[7] Vivek, V., Zheng, Y. and Kim, E.-S., “Novel Acoustic-Wave Micromixer,” 2000 The Thirteenth Annual international Conference on Micro Electro Mechanical Systems, Miyazaki, pp. 668673 (2000).
[8] Jen, C.-P., Wu, C.-Y., Lin, Y.-C. and Wu, C.-Y., “Design and Simulation of the Micromixer with Chaotic Advection in Twisted Microchannels,” Lab Chip, Vol. 3, pp. 7781 (2003).
[9] Li, L., Lee, J.-L., Castro, J.-M. and Yi, A.-Y., “Improving Mixing Efficiency of a Micromixer by Use of a Plastic Shim Divider,” Journal of Mechanics and Microengineering, Vol. 20, pp. 3501235020 (2010).
[10] Tofteberg, T., Skolimowski, M., Andreassen, E. and Geschke, O., “A Novel Passive Micromixer: Lamination in a Planar Channel System,” Microfluid Nanofluid, Vol. 8, pp. 209215 (2010).
[11] Heijne, A.-T., Hamelers, H. V. M., Wilde, V.-D., Rozendal, R.-A. and Buisman, C. J. N., “A Bipolar Membrane Combined with Ferric Iron Reduction as an Efficient Cathode System in Microbial Fuel Cells,” Enviorn. Sci. Technol., Vol. 40, pp. 52005205 (2006).
[12] Min, B. and Lagan, B.-E., “Continuous Electricity Generation from Domestic Wastewater and Organic Substrates in a Flat Plate Microbial Fuel Cell.” Enviorn. Sci. Technol., Vol. 38, pp. 58095814 (2004).
[13] Wang, H., Iovenitti, P., Harvey, E. and Masood, S., “Mixing of Liquids Using Obstacles in Microchannel,” Procesdings SPIE, BioMEMS and Smart Nanostructures, Vol. 4590, pp. 204212 (2001).