The use of fossil fuels, especially oil and gas for all human needs in recent years has accelerated and this triggers the global energy crisis. The need of using alternative power sources, which can gradually replace the traditional energy fuels, is need of the hour. At the present, fossil fuels such as coal, oil, natural gas and their derivatives satisfy almost 85% of the energy demands. Unfortunately, the earth reserves of these fuels are limited. Because of technical revolution and increasing people’s population, exploitation of these sources intensified, and after one and a half century, almost half of the existing fossil fuels on our planet will be consumed. The conventional carbon fuels shortage combined with the rising content of greenhouse gases in the atmosphere, leading to global warming, enforce the necessity of new alternative energy sources utilization. In addition, as supplies of fossil fuels dwindle and concerns about continued contributions of additional carbon dioxide to the atmosphere intensify, there is an increasing need for new sources of energy from renewable sources with minimal negative environmental impact. In this article, Dr. Jahangir Ahmad Rather, Assistant Professor in the Department of Chemistry of the College of Science at Sultan Qaboos University, speaks about microbial fuels cells and its applications.

• Could you explain the use of microorganisms to produce energy? How far has research in this field progressed?

Renewable bioenergy is viewed as one of the ways to decrease the current global warming crisis. It is well known that fuels, such as ethanol, butanol, methane and hydrogen can produce by microorganisms. However, the electricity production using microbes, which is known as microbial fuel cells (MFCs), is recent development in energy biology and highly attracting area. Microbial fuel cells put forward the possibility of harvesting electricity from organic waste and renewable biomass. Biomass, especially organic waste, is being considered as a valuable candidate. The use of biomass, in the case of waste organics, is environment friendly and regarded as a renewable energy source. Research on MFCs is at present receiving a striking increase in interest because these devices can directly convert a large diversity of organic compounds into electricity. MFCs possess a number of advantages over the currently used technologies for generating energy from renewable sources and have high conversion efficiency. The MFCs operate at ambient temperatures and do not pollute the environment. This is the reason why they have the potential for application in locations lacking electrical infrastructure. Except for getting energy, in the same time, they can be used for wastewater treatment; powering marine devices with oxidation of sea sludge; as bio-batteries; in spacecraft’s, etc.

• Do you think that microbial fuel as a promising field for the GCC countries?

The GCC nations have each set different strategic goals of producing certain share of their total energy from renewable sources within the next two decades. Amidst vulnerable oil prices, increased awareness of dwindling fossil fuel reserves and rising global environmental concerns, a switch towards more energy efficient ways and integration of alternative resources in the current energy mix is an impending call. The importance of reducing society's dependence on non-renewable energy sources is urgent especially due to the world’s energy crisis. Oman has 0.3% of the world’s crude oil reserve, which has started to decline from 2015. This is a matter of serious concern because the energy demand for the rapidly developing Omani society is increasing exponentially. Hence, an alternative and sustainable energy research is of strategic importance to the Sultanate. The country has to adopted policies to carry and sustain implementation of renewable energy projects across the Sultanate on a small, medium and large-scale.  In the future, the energy crisis faced by Oman can be minimized by using microbial fuel cells.  MFCs have operational and functional advantages over the technologies currently used for generating energy from organic matter. First, the direct conversion of substrate energy to electricity enables high conversion efficiency. Second, MFCs operate efficiently at ambient, and even at low, temperatures distinguishing them from all current bio-energy processes. Third, an MFC does not require gas treatment because the off-gases of MFCs are enriched in carbon dioxide and normally have no useful energy content. Fourth, MFCs do not need energy input for aeration provided the cathode is passively aerated.

• Can you summarize the applications of microbial energy?

Researchers have suggested that microbial fuel cells can be used for a wide range of applications, including serving as household electrical generators and powering items such as small portable electronic devices boats, automobiles, electronics in space and self-feeding robots. Another interesting area is developing large-scale microbial fuel cells for the conversion of sewage and other organic waste to electricity and the bioremediation of contaminated environments. At present, microbial fuel cells can produce enough current to power small electronic devices for short periods or to trickle-charge capacitors for applications with higher power demands.

The field of MFCs is in its infancy and this is an exciting time in microbial fuel cell research. The well coordination efforts of different scientific fields like electrochemists, materials scientists, engineers and microbiologists is well require in the development of the several potential practical applications of microbial fuel cells. Even, if the generation of high levels of electricity from microbial fuel cells is a long way off, an understanding of the coupling of organic matter oxidation to electron transfer to electrodes is likely to yield important insights into the diversity of microbial respiratory capabilities and might lead to as-yet-unforeseen applications in nano-electronics. We as electrochemists at the department of chemistry, SQU is now exploring the ways to collaborate with other scientists to develop microbial fuel cell devices for real applications to support the sultanate energy resources.