Microbial Fuel Cell; Bacteria-based Alternative Energy

February 22, 2011

By UKM Student English Forum

Editor UKM Student English Forum

BANDUNG, itb.ac.id - Microbial Fuel Cells, or MFC, is an electricity-generating mechanism that utilizes bacterial interactions in the nature. Bacterias living in organic mediums convert organic materials into electricity. The capability of bacterias to break down organic mediums (enrichment media) in MFC can generate electrons and protons. These ions will then generate electric potential difference, which in turn can be utilized into becoming an energy source.

Generally, MFC consists of two chambers; each containing an anode and a cathode respectively. These two chambers are separated by a membrane where proton exchanges occur. This system has not fully worked because the only chamber containing bacterias is just the one with an anode in it. At this moment, the other chamber is still using chemical compounds such as Polyalumunium Chloride (PAC). Even so, recent developments in the MFC technology has utilized biocathodes; cathodes with bacterias. These bacterias will play the same role as any chemical compounds previously used.

In most MFC researches, the substance commonly used so that the bacterias can generate electricity is acetate. Acetate is more easily processed than other contenders such as waste water. Acetate is known to be a simple compound that can function as a source of carbon for the bacterias. Another benefit of using acetate is that the compound does not produce other reactions on the bacterias such as fermentation and methanogenesis in room temperature.

Biocathodes 'versus' Abiotic Cathodes

Using biocathodes is a good choice compared to using abiotic ones due to its lower production and operational cost. Also, some types of bacterias are able to produce oxygen through photosynthesis, lowering external oxygen use.

Biocathodes can prolong MFC ages because platinum plates used in abiotic cathodes can degrade slowly in age due to the sulphure mediator it's constantly exposed to. A type of microbe that can be utilized as biocathodes is the Acetobater aceti.

Still Requiring Further Research

Currently, MFC can only produce around 793 miliAmpere on 1.5 Volt of electricity after running for a week. Researchers hope that the newly developed technology would be able to produce around 12 Volt on 1 Ampere.

Taken and translated from the MFC research publication written by I Nyoman P. Aryantha, Ph.D and Shinta Asarina, S.Si titled Microbial Fuel Cell 9MFC) Based on Electrodes - Semisolid Microbial with 12 Volts and 1 Ampere Scale in the 2010 ITB Research Convention.