TITLE:
An Experimental Study of Microbial Fuel Cells for Electricity Generating: Performance Characterization and Capacity Improvement
AUTHORS:
Jessica Li
KEYWORDS:
Microbial Fuel Cells; Sustainable Energy Source; Renewable Electricity Production Capacity; Power Source of Environmental Sensors
JOURNAL NAME:
Journal of Sustainable Bioenergy Systems,
Vol.3 No.3,
September
13,
2013
ABSTRACT:
This paper studies the
electricity generating capacity of microbial fuel cells (MFCs). Unlike most of
MFC research, which targets the long term goals of renewable energy production
and wastewater treatment, this paper considers a niche application that may be
used immediately in practice, namely powering sensors from soils or sediments.
There are two major goals in this study. The first goal is to examine the
performance characteristics of MFCs in this application. Specifically we
investigate the relationship between the percentage of organic matter in a
sample and the electrical capacity of MFCs fueled by that sample. We
observe that higher percentage of organic matter in a sample results in higher
electricity production of MFCs powered by that sample. We measure the thermal
limits that dictate the temperature range in which MFCs can function, and
confirm that the upper thermal limit is 40℃. The new observation is that the
lower thermal limit is -5℃, which is lower than 0℃ reported in the
literature. This difference is important for powering environmental sensors. We
observe that the electricity production of MFCs decreases almost linearly over
a period of 10 days. The second goal is to determine the conditions under which
MFCs work most efficiently to generate electricity. We compare the capacity
under a variety of conditions of sample types (benthic mud, top soil, and marsh
samples), temperatures (0℃, 40℃, and room temperature), and sample sizes
(measuring 3.5 cm × 3.5 cm × 4.6 cm, 10.2 cm × 10.2 cm × 13.4 cm, and 2.7 cm × 2.7 cm × 3.8 cm), and
find that the electricity capacity is greatest at 0℃, powered by benthic mud
sample with the largest chamber size. What seems surprising is that 0℃ outperforms both room temperature and benthic mud sample outperforms marsh
sample, which appears to be richer in organic matter. In addition, we notice
that although the largest chamber size produces the greatest capacity, it
suffers from efficiency loss. The reasons of these observations will be
explained in the paper. The study demonstrates that the electricity production
of MFCs can be increased by selecting the right condition of sample type,
temperature, and chamber size.