The microbial fuel cell (PCM) is an electrochemical and biological system that produces electricity from the oxidation of organic compounds in the fuel (waste water). It consists of a reactor in which the bacteria present in the anode compartment degrade organic matter and release electrons which are directed through an external circuit connecting the two electrodes. Although this system allows the wastewater treatment and the production of electrical energy, many obstacles may delay its industrial application. The electric power generated by the PCM is dependent on several factors including the concentration of the substrate, the temperature and pH. These frequent and unavoidable disturbances make the internal resistance varying, therefore, affect the generated power.
In this study, the approach of the intermittent connection was used to manage the impedance mismatch problem and investigate the problem of power decrease in PCM continuous operation mode. A dynamic adjustment of the switch, which ensures the intermittent mode, allowed monitoring the optimum power at all times. Two scenarios were performed to compare the generated power of the continuous mode to the one generated in an intermittent mode of operation.
The first scenario is the terminals voltage control of the integrated switch between the PCM and the load (a capacitor in parallel with a resistor). The switch control has been possible thanks to the adjustment of minimum and maximum thresholds of the voltage reached by the capacitor. The experimental results aim to conclude that the intermittent connection of the PCM allows better long-term power performances.
The second scenario is the intermittent connection of the electrical equivalent model of the PCM to feed a battery. A BOOST converter has been built between the switch and the battery. Simulation results have shown that the duty cycle adjustment of the switch allowed the intermittent mode to achieve performance continuously. However, the equivalent electrical model of the PCM does not describe its biological aspect. It causes degradation in long-term performance when the PCM is connected continuously.
| Date | 30 Mar 2016 |
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| Original language | French |
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| Awarding Institution | - École de technologie supérieure
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| Supervisor | Lyne Woodward (Supervisor) |
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Sebei, S. (Author),
Woodward (Supervisor),
30 Mar 2016Student thesis: Master's thesis › Master in Engineering: Electrical Engineering