Research is being carried out into the construction of all types of fuel cells. Fuel cells are batteries. Unlike conventional batteries, fuel cells, as the name suggests, require fuel. In fuel cells, there is a fuel – ie methane is popular today – that is converted ionically, creating positively charged hydrogen atoms that are passed through a polymer material called PEM, or a proton exchange membrane. Yes! That quickly becomes a technology freak. But let’s just call the fuel cell a magic box for now – “fuel” goes in and electricity comes out.
Did you notice anything in the last sentence? How about a turbine and a generator? Talk about getting rid of the middle man!
Scientists have been working on fuel cells for a long time. The first fuel cell was already attributed to William Grove from Scotland in 1838. It was made of zinc and platinum for electrodes in a sulfuric acid bath. What I found as fascinating as his discovery was this: Where did you get platinum back then? His discovery was used early on for telegraphs. Interestingly, the original name for fuel cells was “gas cell”. OK, so what’s up with the microbes?
Well, microbial fuel cells came onto the market a little later, around 1911, by the former President of the British Mycological Society, Professor Micheal Cresse Potter. Very little is known about this man and that is a shame. His work has initiated what may be the most effective way to solve our energy and climate problems – ever. His discovery was that E. coli, a bacterium, could generate electricity. Since its discovery, a whole new chapter in energy production has opened up. Scientists around the world used this knowledge, which eventually turned into the manufacture of today’s MFCs.
MFC is still in its infancy. For now, it’s a matter of determining what applications are viable for MFC in its current technological evolution. An application of MFC is used to teach young students the basics of fuel cells. Students learn that electricity can come from both living organisms and abiotic, non-living sources. You will learn that fuel cells do not have a “Carnot efficiency”. In other words, this was the middleman mentioned at the beginning of this article, the turbine and generator, which require heat-based energy transfer from motion to electricity. You will learn something about the metabolism, i.e. the entire chemical reactions of a living organism. Consequently, they learn about the process of MFCs, and that is catabolism. Catabolism is the breakdown of a source of complex chemistry into a more digestible form that ultimately produces energy.
“Bioelectrochemical systems (BES) have recently developed into an exciting technology. In a BES, bacteria interact with electrodes using electrons that are either removed or supplied through an electrical circuit. The most commonly reported type of BES are microbial fuel cells (MFCs), in which useful energy is generated from electron donors such as those found in wastewater. This form of charge transport, known as extracellular electron transfer, has previously been extensively described in relation to metals such as iron and manganese. The importance of these interactions in global biogeochemical cycles is essentially undisputed. A variety of bacteria can participate in extracellular electron transfer, and this phenomenon is much more widespread than previously thought. The use of BESs in various research projects is helping to elucidate the mechanism by which bacteria transport electrons to the outside. New forms of interactions between bacteria have been discovered, showing how multiple populations within microbial communities can work together to produce energy. New environmental processes that were previously difficult to observe or study can now be simulated and improved via BES. While pure culture studies make up the majority of studies conducted to date, even greater contributions from BESs are expected to occur in natural settings and with mixed microbial communities. Because of their versatility, unmatched level of control, and ability to sustain novel processes, BES could very well serve as the basis of a new environmental biotechnology. While highlighting some of the key breakthroughs and addressing only recently obtained data, this report indicates that despite rapid progress, many questions remain unanswered.”
Wastewater treatment is the first major industry to have a ready fuel source for the MFC, the sludge.
MFC wastewater treatment applications serve two purposes. It minimizes the bacteria in the mud and generates electricity. Current research on MFC directly targets specific bacteria. It seems to come down to the fact that certain types of bacteria are better at producing energy than others. Recent studies show that cow dung has been shown to produce a bacterium that has a higher electrical potential than others. However, getting a higher voltage is now managed by PMS.
Hold tight! The PMS here are power management systems. They are designed to bring the low voltages generated in MFC to a practical working level with predictable consistencies for variations from the MFC.
Another interesting application was the use of MFC to power a cardiac pacemaker. This device was intended to use the person’s own internal “by-products” and power a pacemaker. I haven’t seen much since its inception, but as an engineer I could only see tremendous problems installing the device, maintaining the device in a hostile chemical environment, and then connecting to the heart from a source too far away. Ironically, the previously mentioned disadvantage of the low output voltage is an advantage here.
It’s too early to say if MFC has enough merit, but research is ongoing. Generating electricity from natural sources could lead to further advances. Perhaps we could actually breed electrically producing organisms. Perhaps advances in research could be applied to space. Research often leads to other discoveries. NASA has produced numerous by-products in its research that have aided the medical sciences, new materials and advances in solar cells on their way to the moon and the truly great afterlife with the Webb telescope.
James Bobreski of Penn Yan has been a process control engineer in power generation for 43 years. He is also the author of Alternative Energy and Climate Change in the Age of Trump, available at Longs’ Bookstore and on Amazon.com.