Advances in anodes and cathodes move microbial fuel cells closer to practical uses.
Microbial fuel cells (MFCs) remain a laboratory curiosity—bugs powering bug-sized motors by converting sugar or other organic materials into electricity. In a move to scale up the power generated by MFCs, Bruce Logan and colleagues at the Pennsylvania State University developed two new electrodes. The work is described in a companion pair of papers published today on ES&T's Research ASAP website
Yi Zuo, Pennsylvania State University(es0627601 and es062644y).
Microbial fuel cells (MFCs) remain a laboratory curiosity—bugs powering bug-sized motors by converting sugar or other organic materials into electricity. In a move to scale up the power generated by MFCs, Bruce Logan and colleagues at the Pennsylvania State University developed two new electrodes. The work is described in a companion pair of papers published today on ES&T's Research ASAP website Yi Zuo, Pennsylvania State University(es0627601 and es062644y).
"We have followed this work with interest," says John Hruby, an environmental supervisor with Gerber Products Co. "These two papers are breakthroughs in engineering real systems applicable in today's world," he says. Hruby believes that eventually MFCs can help the food processing industry convert high-strength organic wastewater, which is expensive to treat and dispose of, into an asset. Logan's group achieved a power density of 2400 milliwatts per square meter, a new high for an air-cathode system. Power density was normalized to the area of the cathode rather than the anode, because "the anode surface area is so large that it no longer would affect power generation," says Logan. The cathode, likely to remain the most expensive component, "is what is limiting power on a surface-area basis." The MFC produced 73 watts per cubic meter of its reactor volume; a reactor the size of a typical refrigerator might produce 100 watts.
