More than half energy produced annually—whether it’s heat, gas, biomass, or methane—is wasted. Harvesting the wasted heat energy could reduce carbon dioxide emissions by 17 percent. Researchers from the Department of Civil and Environmental Engineering at Penn State are looking for new, environmentally friendly ways to harvest and recycle this wasted energy in an effort to create hydrogen gas.
“Existing methods are already very effective at making hydrogen gas,” says Bruce Logan, Evan Pugh Professor of Environmental Engineering. “The problem is that these methods consume fossil fuels in order to generate enough energy to create the hydrogen gas.”
By producing hydrogen gas via waste heat, the researchers eliminate the need for fossil fuels in production.
“Since the new system runs on waste heat, it is effectively carbon neutral and fossil fuel neutral,” says Logan.
This from Pennsylvania State University:
Ammonium bicarbonate and water are separated into high and low salt concentration streams using distillation, much like the process for distilling alcohol. Those streams are then fed into a reverse electrodialysis stack, which consists of a series of alternating charge (cation and anion) ion exchange membranes. This process creates an electrochemical reaction that splits the water forming both oxygen and hydrogen at the other electrode. That hydrogen can then be used on site, for example to make ammonia, or it can be compressed and containerized for a variety of other purposes.
Even though similar systems have been designed in the past, this is the first of its kind specifically created for hydrogen gas production.
“Many countries are limiting carbon emissions, and thus new carbon neutral methods are needed to produce transportable fuels,” says Logan. “This process can help with both of those goals.”
In order to make the novel device commercially viable, the researchers must now find a cost effective solution for the expensive membranes used.
