Design and fabrication of microbial fuel cell for generation of electricity

Vishnu Agarwal

doi:10.17485/ijst/2011/v4i3.7

Abstract

Energy need has been increasing worldwide exponentially. At present global energy requirements are mostly dependent on the fossil fuels, which eventually lead to foreseeable depletion of limited fossil energy sources. More recently, generation of electricity using microbial fuel cells (MFC) is seemingly gaining importance in the research. MFC is a biochemical-catalyzed system which generates electrical energy through the oxidation of biodegradable organic matter in the presence of either fermentative bacteria or enzyme under mild reaction conditions (ambient temperature and pressure) and bacterial energy is directly converted to electrical energy and to close the cycle, protons migrate through a proton exchange membrane (PEM) from anode to cathode. The present work deals with the designing and fabrication of two-chambered salt bridge microbial fuel cell with specific dimension. The efficiency of fabricated MFCs was checked by variation in current produced on different days of operation of MFC and effect of using dextrose in anodic chamber of MFC. The MFC was operated for 7 days with or without dextrose as carbon source. It was observed that while running MFC without dextrose the maximum current obtained was 13.6 μA and maximum voltage obtained was 146.8 mV. However while using 5% dextrose solution in the anodic-chamber the maximum current and voltage obtained was 170 μA and 216 mV respectively.

Highlights

Introduction outer-membrane redox proteins to Microorganisms act as a catalyst in the transfer of mediate the electron transfer to exocellular solid electrons from the substrate to the anode, the selection substrates upon contact (Luo et al, 2010)
It was observed that minimum current (18.1 μA) obtained on the first day was more than the maximum value of current (13.6 μA) of microbial fuel cell (MFC) operating without dextrose as carbon source
Basic reason for increase in current is that in initial phase anaerobic bacteria which were responsible for electricity generation were inactive in presence of oxygen but when they were inoculated under anaerobic conditions they starts activating themselves start degrading organic matters present in anode chamber

Summary

Introduction

Introduction outer-membrane redox proteins (e.g. cytochromes) to Microorganisms act as a catalyst in the transfer of mediate the electron transfer to exocellular solid electrons from the substrate to the anode, the selection substrates upon contact (Luo et al, 2010). Microbial fuel cells (MFCs) use microbes as anode findings extend the view of the exocellular catalysts. The key for bacterial cells to function as Anode chamber volume was calculated using equation catalysts in MFCs is their capability to use the fuel cell OLR = (CSO × feed rate)/reactor volume anode as terminal electron acceptor.

Results

Conclusion