First steps towards a constructal Microbial Fuel Cell

Area of Science:

• Energy Conversion and Storage
• Electrochemistry
• Fluid Dynamics

Background:

• Microbial Fuel Cells (MFCs) are promising for sustainable energy generation.
• Optimizing reactor design is crucial for enhancing MFC performance and real-world applicability.
• Organic charge flow and entropy generation are key factors affecting MFC efficiency.

Purpose of the Study:

• To design and optimize a multi-channel reactor for Microbial Fuel Cells (MFCs) under real operating conditions.
• To apply constructal theory for minimizing entropy generation in the fluid distribution system.
• To evaluate the efficiency and robustness of the designed MFC.

Main Methods:

• A two-dimensional, feed-through double chamber reactor with four parallel channels was designed.
• Reticulated Vitreous Carbon was used as electrodes.
• Thermodynamical calculations and Hess-Murray law were employed to optimize the constructal-inspired distributor.
• Entropy generation was determined based on global hydraulic resistance.

Main Results:

• The constructal-inspired design effectively reduced entropy generation along the distributing path.
• Polarization, power, and Electrochemical Impedance Spectroscopy (EIS) confirmed the cell's robustness and efficiency.
• The study demonstrated the potential of the constructal approach in MFC design.

Conclusions:

• The optimized multi-channel MFC reactor shows significant potential for efficient organic charge flow.
• Constructal theory provides a valuable framework for improving MFC design and performance.
• Further design evolutions can lead to enhanced MFC systems.