Mar 17 2016
A new fuel cell that transforms urine into electricity could revolutionize bioenergy production, especially in developing countries. The research work, published in Electrochimica Acta, discusses a new microbial fuel, which is cheaper, smaller in size and more powerful than the conventional ones.
The world’s fossil fuel supply is decreasing and there is a greater need to discover new renewable energy sources. One example is bioenergy, which can be produced by microbial fuel cells.
Researchers from the University of Bath, Queen Mary University of London and the Bristol Robotics Laboratory, have designed a new microbial fuel cell that does not have the two drawbacks facing the conventional microbial fuel cells: low power production and high cost.
Microbial fuel cells have real potential to produce renewable bioenergy out of waste matter like urine. The world produces huge volumes of urine, and if we can harness the potential power of that waste using microbial fuel cells, we could revolutionize the way we make electricity.
Dr. Mirella Di Lorenzo, University of Bath
Microbial fuel cells utilize the natural processes of specific bacteria to transform organic matter into electric energy. Bioenergy can also be produce by other methods such as; fermentation, anaerobic digestion, and gasification. But microbial fuel cells can be operated at room temperature and pressure conditions. They are efficient, have a low cost of operation, and generate less waste compared to other methods.
Some limitations do exist. It is quite expensive to manufacture microbial fuel cells. Although the electrodes are generally made out of cost-effective materials, the cathode usually contains platinum, which is needed to accelerate the reactions for electricity generation. Additionally, microbial fuel cells produce less power in comparison to other bioenergy production methods.
The innovative miniature microbial fuel cell developed by the researchers does not use costly materials for the cathode. Titanium wire and carbon cloth are the cost-effective substitute materials. To accelerate the reaction and generate more power, the new fuel cell utilize a catalyst made up of ovalbumin and glucose, the former being a protein present in egg white. These are typical elements of food waste.
We aim to test and prove the use of carbon catalysts derived from various food wastes as a renewable and low-cost alternative to platinum at the cathode.
Dr. Mirella Di Lorenzo, University of Bath
The design was then changed slightly to determine how to generate more power. Extending the electrode length from 4 mm to 8 mm yielded 10 times more power. Additionally, stacking up three miniature microbial fuel cells increased the power output tenfold when compared to the power produced by individual cells.
Microbial fuel cells could be a great source of energy in developing countries, particularly in impoverished and rural areas. Our new design is cheaper and more powerful than traditional models. Devices like this that can produce electricity from urine could make a real difference by producing sustainable energy from waste.
Jon Chouler, University of Bath
“We have shown that the cell design has an incidence on performance and we want to further investigate the relevance of electrode surface area to volume ratio on performance. Our aim is to be able to effectively miniaturize the MFC and scale-up power production by generating compact batteries of multiple miniature units,” added Dr. Di Lorenzo.
Source: https://www.elsevier.com/