971281Electricity from waste using stacks of Microbial Fuel Cells (MFCs)ClosedSmall Business Research InitiativeInnovate UKElectricity from waste using stacks of Microbial Fuel Cells (MFCs) MFCs are a relatively new technology that harvests energy from organic waste, through the metabolic activity of constituent biofilm microorganisms. Up until recently, the technology was perceived as a laboratory curiosity, but we have already demonstrated how it can be realistically scaled up to meet the requirements of various applications. The breakthrough in this respect lies with miniaturisation & multiplication rather than enlarging single units. Using this approach we have already demonstrated that we can get useful amounts of practical power from small MFCs in a 48-unit stack. Through this work we have fostered the expertise and know-how to build truly useful large stacks (n=1000) using modular mass production based on inexpensive materials. Our MFCs have been constructed using the rapid prototype (RP) technology, and this will also be utilised as the first step in facilitating mass production of a stack system, for this project. It must be said that if funding is granted, this would be the world's first truly large-scale stack that fulfils all the main criteria regarding alternative, fossil-free energy (electricity) from waste biomass (e.g. from detritus to urine; stuff too-wet-to burn) and in addition synthesising water at the cathode. The proposed work is in perfect alignment with Dr. Ieropoulos's (Co-applicant) EPSRC Career Acceleration Fellowship (EP/I004653/1), as well as with our "Urine-tricity" project, funded by the Bill & Melinda Gates Foundation (OPP1044458). The principle of operation is based on electrodes colonised by biofilm organisms, which continue to grow and shed new daughter cells (progeny) for as long as the fuel (waste) is supplied. In other words, the inputs to the MFC are organic waste at the anode and oxygen at the cathode, and the outputs are electricity, CO2 (but avoiding fossil fuels) & treated waste from the anode, and water synthesised from the cathode. Progeny cells consist of the soluble elements (C, N, P, S and K) that have been removed from the waste and "locked-up" into the new biomass. The progeny can be separated (making good fertiliser) whilst the relatively clean residual solution can be safely returned to the environment or re-cycled by other means. In essence, our MFC stacks clean up waste and produce (rather than consume) energy and water. As such they will be of particular interest to the food, power and water sectors of the economy. All organic waste should now be seen as fuel, of which there is an abundance, and as such falls directly within the international priority for "excreta sludge management". Our aims in Phase 1 (first 13 weeks) are to build a modular stack, using ceramic & polymeric 3D printing, to produce up to 18 units within modules (or large "tile"). The other components include inexpensive carbon electrodes, gaskets, tubes and wires that will be assembled to make a module and in turn modules combined to make stacks and super-stacks. A 1000-unit system consisting of modules manufactured by different approaches will enable us to effectively assess performance parameters e.g. waste clean-up & power production and therefore calculate economies of scale and likely implementation in different market sectors. This will inevitably attract carbon credits (methane and CO2) and pave the way towards green electricity as well as clean water production for re-cycling. Note to reviewers:Please see Appendix A for images and references list