New device turns sewage and sunlight into fuel
A new device combines a microbial fuel cell and photoelectrochemical fuel cell uses nothing but sunlight and waste energy to produce hydrogen gas.
A research team led by Yat Li of the University of California, Santa Cruz, has discovered a new device that could provide a new way of obtaining hydrogen gas as a fuel source. The system uses sunlight and waste water to produce the hydrogen using a combination of a microbial fuel cell and a photoelectrochemical cell.
In the first stage of the device, bacteria breaks down organic matter in the waste water, generating electricity in the process. The generated electricity is then used to drive the solar-powered component, which splits the remaining water into oxygen and hydrogen.
Both parts of the device can be used independently to produce hydrogen gas, but require an additional voltage to overcome the energy barrier that is required for proton reduction of the water into hydrogen gas. Unfortunately, this additional voltage requirement makes such a device not very cost effective, and this is where Li’s device finds it’s niche: Because both devices work together, it’s self sustaining and self powering.
Hydrogen is becoming an increasingly important fuel source.
“The only energy sources are waste water and sunlight,” explains Li, “The successful demonstration of such a self-biased, sustainable microbial device for hydrogen generation could provide a new solution that can simultaneously address the need for waste water treatment and the increasing demand for clean energy.”