Objectives/Goals of the project
The main objective of this project is to move forward the MFC technology for its practical implementation and integration to the current wastewater treatment practices. In order to accomplish this goal, a multiple air cathode MFC configuration is currently optimized, as a unit and as a part of a stack, in terms of simultaneous power production and wastewater treatment. In view of MFC commercialization, the cost is kept relatively low by replacing the expensive construction materials with cheap but effective ones. Moreover, a set of specific objectives have been defined that highlight where the project is focused on:
The construction and optimization of multiple air cathode MFCs.
The present research proposes the scaling–up of a single-chamber MFC with a special architecture, which has been already constructed and tested under the frame of a PhD research. This design aims at minimizing the electrochemical losses, which limit MFC performance, while reducing the capital cost of the system. The singularity of the four air cathode MFC configuration is in its design as well as in its specific selection and combination of its materials. This system lies in the usage of multiple cathode electrodes and the lack of membrane and expensive noble metal catalyst so that the cost is maintained low, while a high area per unit reactor volume is available for proton transfer. In particular, carbon granules serve as the anodic biofilm support and conducting material, conveying electrons to a graphite rod, inserted into the packed bed of granules. Four plexiglas tubes supporting the cathode electrodes, run through the chamber. The proposed design is further optimized under the scope of minimizing the electrochemical losses, which limit the MFC performance while keeping the capital cost low. In this direction the design is optimized in terms of dimensions etc. while different materials are investigated.
The stacking of the MFC units is an objective of primary importance, since it is a step towards scaling -up the technology. However, stacking the MFC units carries its own challenges, since issues like cell voltage reversal phenomenon arise. Voltage reversal occurs when one of the cells exhibits a much larger resistance than other cells in the stack. It therefore become
s vital how such stacks may be configured electrically and fluidically. The goal of this research is to construct a smart stack which will be able to address the voltage reversal phenomenon often observed in multiple electron devices connected together. The term smart lies in the special way that the stack will be constructed in order to avoid such obstacles.
The work plan of WHYMFC has been structured in 5 Work-Packages (WPs) that cover a 36 (3 years) time period. Particularly, during WP1 various MFC units are constructed and operated under various conditions. The main aim of WP1 is to produce the appropriate MFC unit for scaling up the technology through stacking. WP1 is strongly connected with all the other WPs since it acts like a tank for the materials produced during WP2 and WP3 and it produces all the appropriate data for WP4. The results from WP1 give feedback to WPs2 and 3, where further optimization of the materials occur. Specifically, during WP2 ceramics are produced for their use as medium for ion exchange and as structural material for cathodes and anodes. Furthermore, the main aim of WP3 is the optimization of anode and cathode reactions through the optimization of electrodes. WP5 focuses on the dissemination and exploitation of all the valuable data produced from the project.