North Carolina State University is seeking an industry partner to further develop and commercialize an engineered biocomposite that provides an effective solution for compact renewable electricity generation.
The demand for low cost renewable electricity sources is constantly growing. An example of such renewable resources are microbial fuel cells (MFC), which convert waste organic materials and light energy into electrical energy. Although microbes and organic wastes are abundant, the following limitations hinder the commercial application of MFCs: (a) internal resistance of the fuel cell, (b) the effectiveness of the microbes to convert substrate into electrons, © the convective transport of materials in the substrate, (d) the volumetric loading of the microbes, and (e) the low electro-chemical potential across the bacteria membrane (1.1 v). To achieve sufficiently high voltage and current, the microbial fuel cells must be connected in series and have sufficient high density of bacteria to adequately transport current flow. None of the existing technologies can effectively solve these limitations. Therefore, there is a great commercial opportunity for an inexpensive technology that significantly enhances the cellular and current density of MFCs, while using minimal amounts of water and not compromising the porosity of the biocomposite.
Researchers at NC State University have developed a cellulose-based microbial paper biocomposite that could dramatically enhance the cellular density of microbial fuel cells. Engineering a mixture of nanofiber cellulose and wood fiber produces a synergistic effect that will allow for the creation of compact MFCs. The wet-lay process that produces this biocomposite is scalable, and it provides controlled drying conditions to entrap microbes within the paper in their living state. This technology enables layered MFCs that create 110 volts in a 2-cm stack, using inexpensive paper-based biocomposites. Furthermore, the production technique allows for addition of carbon fibers or other materials to make conductive biocomposites. A significant fraction of carbon fiber can be incorporated into these cellulose + cell paste composites, further enhancing their properties for fuel cell applications. This creates an entirely new intensified approach to create useful electrical energy from waste materials. In addition, these MFCs can be used as reactive biofilters, as current generating biosolar energy harvesting devices, and act as power generators in wastewater treatment facilities.
For the biotechnology, wastewater treatment, and energy industries who are looking for renewable and sustainable resources to generate electricity, this technology offers a scalable process to fabricate cellulose-based microbial fuel cells. Unlike the current MFCs that generate a limited amount of voltage, these biocomposites provide high living cell densities to provide significant electro-chemical potential, and have micropores that enable the transport of nutrients and gases.
- Cellulose-based microbial paper biocomposite
- Renewable source of energy with tailored embedded microbe and conductive properties
- Significantly increased cell density at the anode generating useful current density
- Synergistic effect of constituent materials for engineered microbial fuel cells
- Valuable applications in different industries such as power generation, biosolar energy harvesting, wastewater treatment, and MSW/food waste/biomass to electricity
- Scalable and established wet lay production process with controlled process parameters
About the Inventors
Dr. Joel J. Pawlak is an Associate Professor in the College of Natural Resources, Department of Forest Biomaterials, at North Carolina State University. His research interests focus on the material science and material engineering of multiphase materials. Current research interests include porous fibrous web structures, foams made from natural materials, natural super-absorbents, enzymatic manipulation of material structure, natural nano-scale fiber composites, and novel application of rheological phenomenon.
Dr. Michael C. Flickinger is a Professor in the Chemical & Biomolecular Engineering Department, and the Associate Director of Academic Programs Golden LEAF Biomanufacturing Training and Education Center (BTEC) at North Carolina State University. His research interests focus on biocatalytic coatings, nanostructured bioreactive materials, bioprocess intensification and miniaturization (BIM), coating/photo, microchannel and thin film bioreactor design, combined with microbial metabolic engineering.