Efficiency of Microbial Fuel Cell Made from Inexpensive Materials vs Traditional Microbial Fuel Cell - Essay Example

Efficiency of Microbial Fuel Cell made from inexpensive materials is comparable to traditional MFCs The design study project will include the construction of a Microbial Fuel Cell (MFC) with inexpensive materials and the electricity generation capability will be compared to the traditional MFCs which require expensive membranes like Nafion by DuPont and Platinum cathodes. The simple MFC will be made from plastic containers, PVC pipes, agar or Gore-Tex membranes and galvanized metal mesh for cathodes. The experiment will include comparing the efficiencies defined by amount of energy per dollar spent in the construction and installation process of the traditional MFC, as provided by the college laboratory and the MFC built from common and less expensive substitutes. Key words: MFC designs, cheaper alternative MFC, bioremediation Introduction: We are, today, faced with an extraordinary situation in which the world population has reached a stage where the conventional sources of energy like fossil fuels have been depleted so much that there is little hope for the coming generations to be able to harness any of it. Therefore, there is an urgent need to discover sustainable sources of energy that will not only help in reducing the carbon footprint but can also be replicated in the developing nations. A literature review on such alternative sources of energy revealed that microbial fuel cells, which employ microorganisms to biodegrade pollutants from the environment to generate electricity, are a novel method of reclaiming natural resources along with providing a new means of generating energy. This design study will be an effort towards determining the cost-efficiency of traditional MFCs versus a simple, single chambered MFC comprising of cheaper components. The purpose of the experiment will be to popularize the inexpensive MFCs and show if scaled up, they can present a low-price energy source, which will at the same time be used for bioremediation of water resources polluted by effluents. Microbial fuel cells work on the principle that some microorganisms called electricigens produce electricity while metabolizing wastewater for their sustenance. The MFC consists of a semi-permeable membrane or cation exchange membrane that allows ions to pass through them but not the microbes; two electrodes, usually the cathode is made up of platinum and the anode is carbon graphite or carbon cloth. It is fitted by a wire to complete the external circuit (Microbal Fuel Cell, 2008). Wastewater is made to flow through the anaerobic compartment and the bacterial metabolic action on the wastewater allows electrons to become free and the cell starts conducting electricity. Aim: To compare the electricity outputs from a typical MFC (as present in the college lab) using expensive Platinum cathode and Nafion membrane v/s MFC made from inexpensive material such as Agar or Gore-Tex membrane and galvanized aluminum mesh for cathode. To test the hypothesis that a more cost effective MFC can be constructed from readily available materials, several strains of bacteria will be used to check for energy production. A power to cost ratio chart can then be collated to validate the hypothesis. Methodology and approach to be used: The method to be applied in conducting the experiment is to first make a microbial fuel cell with low-cost and easily available substitute components that have been tried before (Patra, 2008) and learnt about during the literature review process. The materials required include: For the chamber: A cylindrical jar or PVC pipes of 2-3inches, estimated cost approximately $0.75- $1.00 For the cathode: Galvanized aluminium grating like Kiwi-Mesh can cost as low as $12.00/m2 whereas the platinum cathode can cost about $2000/m2 (Patra, 2008). For the anode: Carbon mesh anodes are not very expensive and due to their greater surface area provide an efficient substitute of the carbon graphite rod in many conventional MFCs. The cost is expected to be approximately $620/m2. For the membrane: Agar and Gore-Tex membranes can be utilized to replace the more common but expensive Nafion membranes. Gore-Tex membrane would cost $165/m2 against $2500/m2 of Nafion membranes (Frequently asked questions). The solution used for both traditional and alternative MFC will be glucose solution. Bacteria to be tested are Geobacter sp., Shewanella sp. and co-culture of bacteria obtained from influent wastewater, which is available at almost zero cost versus the more expensive specific electricigen strains (Hou. et al, 2009). Some of the prices have been found online from websites like ScienceStuff.com, but a more elaborate research will be done after going through lab inventory, etc. The independent variables in the experiment are the three different strains of electricigen bacteria that will be tested for energy production; of this, one bacterial sample will be a co-culture obtained from influents. The dependent variable is the amount of voltage produced by the microbial fuel cell. It will be measured with a multimeter in voltage units. A cost-effective analysis will be done by comparing the amount of energy produced per dollar input cost for the traditional MFC and the cheaper substitute (NAPFEE, 2008). The control would be a voltmeter fitted to an MFC with glucose solution of the same strength as the others without any bacterial inoculation. Timeline Day 1: All the necessary materials to build the microbial fuel cell have to be gathered. Day 2: The anode and cathode, the MFC, the agar membranes have to be built. Day 3: The solution and bacterial inoculation have to take place for first set of bacteria. Day 5: Data for current and potential has to be gathered for all three MFCs. Day 6-8: Same steps for different bacterial strain. Day 9-11: Same steps for mixed bacterial culture from industrial influent. Flowchart: Steps to make inexpensive MFC from commonly available material: The data needs to be recorded for the inexpensive and laboratory MFCs using the three different strains of bacteria, separately. Each recording may be taken thrice to find concordant values. Independent variables: Electrodes, membrane, external circuit, MFC body, and the inoculum Constants: Temperature, amount of solution in each MFC Dependent Variable: Voltage produced based on the different factors. Although, the variables are many, the main comparison is between different kinds of MFCs. Table 1: To test design by noting the voltage and current changes in the low-cost MFC and comparing them to the control and traditional MFC from the Lab. Control MFC from Lab Inexpensive MFC Potential (V) Current (mA) Potential (V) Current (mA) Potential (V) Current (mA) Initial Final Initial Final Initial Final Initial Final Initial Final Initial Final Shewanella oneidensis Geobacter sulfurreducens Mixed culture from industrial wastewater According to Ohm’s law, power may be calculated as: P= I*V where, P= power in milliwatts; I is current in milliamps, V= potential in millivolts. The power to cost ratio can then be calculated and compared with the traditional MFC and control. Also the purpose of using the three different strains of bacteria will help establish whether or not the outcome is dependent on the microbe. The cost analysis will be done after referring to logs maintained in the laboratory and from receipts of materials purchased to make the alternative MFC. Safety procedures: 1. The use of rubber gloves is a must when dealing with electrical circuits and carbon mesh. 2. To avoid contamination of microbial samples, the inoculation preparation and introduction can be carried on in a laminar air flow chamber. 3. One must be careful when dealing with hot agar. 4. It is important not to allow skin contact with epoxy raisin. 5. The readings will have to be taken three times to get concordant values. Allowance will have to be made for bacteria which may remain inactive in the broth. Ethical consideration: Although a point of contention may arise if people consider living organisms being used to promote digitization, the bigger question remains that it is in the larger public interest that such studies be promoted. Sustainable alternatives can reduce our dependence on fossil fuels, and support clean fuels and greener environment, as well as help reduce the pollutants already present in our atmosphere. Hence, the pros of MFCs far outweigh any other points of view (Buttermore, 2012). Discussions: It is fast becoming imperative to identify and facilitate energy production using non-conventional and renewable sources in order to sustain the growth and development in nations across the globe. Depleted quantities of fossil fuels and rising fuel prices has spurred scientists to look for alternate resources. Inventions like microbial fuel cells which harness microorganisms to bioremediate polluted resources and in turn, provide energy, have encouraged rapid studies in finding more economical and efficient designs. The aim of this project design is to help decide whether low-cost and easily available materials can be used to build an MFC which is equally or more cost effective than the typical MFCs; and if yes, whether this design can be replicated on a bigger scale and introduced in developing nations that may not have enough resources to buy large scale MFCs to fuel their energy requirements and help in bioremediation. Resources: 1. Addisu, A., 2011. Type of Soil and Size of a Microbial Fuel Cell on Voltage Production, Rockdale Magnet School. [online]. Available at: [Accessed 14 March 2013]. 2. Buttermore, R. (2012). Microbial Fuel Cell: Improving Wastewater Treatment, [online]. Available at: < http://www.pitt.edu/~rwb31/trends.html> [Accessed 15 March 2013] 3. Chakhtoura, JRE., 2011. Harvesting electricity from the organic fraction of municipal solid waste using MFC, American University of Beirut.[pdf] Available at: [Accessed 15 March 2013] 4. Frequently asked questions about MFCs [pdf]. Available at: [Accessed 14 March 2013]. 5. Hou H, Li L, Cho Y, de Figueiredo P, Han A (2009) Microfabricated Microbial Fuel Cell Arrays Reveal Electrochemically Active Microbes. PLoS ONE 4(8): e6570. doi:10.1371/journal.pone.0006570 6. Logan, B. (2008). Make a Microbial Fuel Cell (MFC) - Part 1. Instructables, [online]. Available at: [Accessed 14 March 2013] 7. Logan, B. E., Hamelers, B., Rozendal, R., Schroeder, U., Keller, J., Freguia, S., Aelterman, P., Verstraete, W. and Rabaey, K. (2006, July 14). Microbial fuel cells: Methodology and technology, [online]. Available at: [Accessed 14 Marc 2013] 8. Microbial fuel cells. (2008). [online]Available at: [Accessed 14 March 2013] 9. National Action Plan for Energy Efficiency (NAPFEE), 2008. Understanding Cost-Effectiveness of Energy Efficiency Programs, [pdf]. Available at: < http://www.epa.gov/cleanenergy/documents/suca/cost-effectiveness.pdf > [Accessed 15 March 2013] 10. Patra, A., 2008. Low-Cost, Single-Chambered Microbial Fuel Cells for Harvesting Energy and Cleansing Wastewater, For the Future, From the Future, [pdf]. Available at: < http://www.wef.org/WorkArea/DownloadAsset.aspx?id=2709 > [Accessed 14 March 2013]. 11. Rabaey, K., Lissens, G., & Verstraete, W. (2005). Microbial fuel cells: Performances and perspectives. In P. Lens, Biofuels for fuel cells: renewable energy from biomass fermentation (pp. 377-391). Padstow: IWA Publishing. Read More