Speaker: Bruce Logan

THE BREN SCHOOL OF Environmental Science & Management
at the University of California, Santa Barbara

Presents

Bruce Logan
Professor
Penn State University


Thursday, April 9, 2009
12:30-1:30 p.m.
Bren Hall 1414

"Opportunities for Bioenergy Production Using Microbial Fuel Cell Technologies"

Hosted by Patricia Holden

 

Abstract

Among the most basic needs in the world are water, food, and energy. Water is abundant, but energy requirements for treatment and distribution are increasing, and over 1 billion people lack adequate potable water. In the US alone, 5% of the electricity produced is used for the water infrastructure. Fortunately, there are readily available sources of waste organic matter than can be used to develop an energy-sustainable water infrastructure. One new approach to produce energy employs microbial fuel cells (MFCs). Naturally occurring exoelectrogenic bacteria can oxidize organic matter and release electrons outside the cell to an electrode (anode) of an MFC. These electrons flow to the counter-electrode (cathode), where they combine with oxygen and protons to form water, generating current and power. Sustained electricity generation is possible using virtually any type of biodegradable organic matter, including pure compounds (acetic acid and other volatile acids, glucose and sugars, amino acids and proteins, etc.), complex organic matter in wastewaters (domestic, animal, food and other industries), and agricultural materials (corn stover hydrolysates and cellulose). It is also possible to bioelectrochemically produce hydrogen or methane gas by bio-electrogenic processes in microbial electrolysis cells (MECs). By modifying the MFC and slightly boosting the voltage (>0.2 V) produced by the bacteria, hydrogen gas can be produced to obtain nearly 100% of the theoretical stoichiometric yield (based on electrons) from nonfermentable substrates such as acetic acid. Typically, two to four times more energy is recovered in the hydrogen gas produced than in the electrical energy used. We have found, based on combustion energies, that 64-82% of the energy in organic matter (including acetate, glucose, cellulose and other biodegradable materials) and the electrical energy added could be recovered in hydrogen gas. Using specific Archae on the cathode, we can alternatively produce methane. Significant challenges remain for scaling up both MFCs and MECs. In this presentation, I review advances in methods for increasing current densities in these devices and approaches for reducing costs and scaling up systems for commercial applications.

Biography

Bruce Logan is the Kappe Professor of Environmental Engineering at Penn State University, and director of Penn State’s Hydrogen Energy Center and the College of Engineering Environmental Institute. He has published over 200 journal papers and several books, in research areas that include bioenergy production, bioremediation, environmental transport processes, colloidal dynamics, and microbial adhesion. He is a visiting professor at Newcastle University in England and Harbin Institute of Technology in China, and an investigator with KAUST in Saudi Arabia. Prior to joining the faculty at Penn State in 1997, he was on the faculty at the University of Arizona in the Department of Chemical and Environmental Engineering.

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