Simultaneous Generation of Electricity and Hydrogen from Biomass and Sunlight via a Microbial Photoelectric CellEPA Grant Number: FP917152
Title: Simultaneous Generation of Electricity and Hydrogen from Biomass and Sunlight via a Microbial Photoelectric Cell
Investigators: Badalamenti, Jonathan Paul
Institution: Arizona State University - Main Campus
EPA Project Officer: Zambrana, Jose
Project Period: August 19, 2010 through August 18, 2013
Project Amount: $111,000
RFA: STAR Graduate Fellowships (2010) RFA Text | Recipients Lists
Research Category: Academic Fellowships , Fellowship - Science & Technology for Sustainability: Energy
The numerous and potentially severe environmental threats associated with meeting energy needs by the continued combustion of fossil fuels are clear. These energy needs must be met from renewable sources well before fossil fuel supplies are exhausted in order to significantly reduce anthropogenic emissions of CO2 into the atmosphere and mitigate harmful environmental impacts. This project will investigate the utilization of photosynthetic microorganisms in a microbial photoelectric cell (MPC) to generate electricity from biomass and, in a simultaneous process, use sunlight to re-energize electrons and produce hydrogen (H2).
Renewable energy is one of the greatest challenges facing human civilization in the 21st century. The sun is Earth’s most abundant power supply, yielding more energy in one hour than consumed by the planet in one year. This project seeks to develop a microbial photoelectric cell (MPC) to extract solar energy stored in waste biomass as electricity in a simultaneous process where photosynthetic microorganisms use sunlight to recapture electrical energy in a fuel such as hydrogen.
The first research stage will evaluate several consortia of photosynthetic bacteria for their ability to interact electrochemically with electrodes of a traditional microbial fuel cell (MFC). Bacterial electrochemical interactions with insoluble substrates, the mechanisms of which are poorly understood, appear to be ubiquitous in nature and occur among representatives of photosynthetic bacteria. MFCs generate electrical current when bacteria oxidize organic wastes and channel electrons to an electrode. In the reverse process, the reduction half-reaction can be catalyzed by bacteria fed electrons from an MFC to reduce oxidized contaminants such as nitrate, perchlorate, and uranium(VI). By overcoming unfavorable thermodynamics using sunlight as additional energy input to an MFC, the research will evaluate conditions under which photosynthetic bacteria may re-energize electrons from an MFC to yield a reduced product such as H2.
High throughput screening of diverse samples enables facile detection of electrochemically active photosynthetic bacteria by monitoring electrical current. With evidence for current-generating and/or -consuming activities of photosynthetic bacteria in an MFC, conditions favoring growth and phototrophy can be optimized and applied to several environmental samples to investigate the ubiquity of electrochemical interactions with insoluble substrates. Such an approach is easily adaptable to several variable inputs such as light regime, electrochemical potential, temperature, and salinity. Moreover, the MPC presents a novel tool for isolating photosynthetic bacteria directly from natural habitats. Combining these results with analyses of microbial ecology using molecular methods on conserved genetic markers identifies and quantifies key microbial players and thus targets for further study and improvement of system performance. These findings will be critical for designing a robust MPC which couples generation of electricity from organic waste and sunlight-driven recapture of electrons in H2.
Potential to Further Environmental/Human Health Protection
Climate change poses arguably the greatest threat to the protection of environmental and human health in this century. Direct contribution of human activities to climate change provides a convincing case for urgent investigation into substitution of fossil fuel-based energy infrastructure with renewable alternatives. The MPC establishes a potential framework to lessen dependence on combustion of fossil fuels, a major contributor to climate change, by generating energy from only renewable inputs.