Harvesting hydrogen from self-powered cells

BBC : Environmental engineers at the Pennsylvania State University are developing a process that involves a microbial fuel cell to treat wastewater and produce hydrogen gas without consuming electrical grid energy. In this method, bacteria break down wastewater by eating the organic material and releasing electrons as a byproduct. Bruce Logan and his coworkers’ prototype attempts to collect those electrons, along with the hydrogen gas produced, in the fuel cell. The electrons are directed through a circuit that can power a small device, such as a fan or a light bulb. Additional hydrogen can be produced from the wastewater by applying extra voltage to the system, which leads to the electrons produced by the bacteria to bond with protons found in the water.To avoid the need for external power, the team members are experimenting with a process called reverse electrodialysis, which generates electricity from the salinity difference between seawater and fresh water. “You’re actually creating energy and desalinating the water and treating the wastewater. It’s a triple play,” Logan was quoted as saying in an NSF press release . Logan hopes that within the next 5–10 years microbial fuel cells will generate enough electricity to power a wastewater treatment plant with energy left over to share with the nearby community.