Researchers in the College of Engineering at Oregon State University have developed a new approach which uses several types of biowaste, including ordinary municipal sewage, to produce hydrogen at a much lower cost than the traditional “electrolysis” technology. Such a process would make it more viable for use in the hydrogen fuel cells that many believe will power automobiles of the future.
The process uses microbial electrolysis cell in a "membrane free" approach that costs less and is significantly more efficient than existing approaches. Naturally occurring microorganisms from sewage attach to the surface of an anode and degrade the waste in the sewage. The waste decomposes, eventually leaving protons that migrate to the cathode, combine with electrons and generate hydrogen.
The researchers believe that their approach could reduce the amount of energy needed to produce hydrogen by as much as 75 percent, compared with hydrogen production by water electrolysis. "In the laboratory we’re already quite close to the Department of Energy hydrogen cost goal of $2 to $3 per gasoline gallon equivalent," said Hong Liu, an OSU assistant professor of biological and ecological engineering. "And with some additional research it should be possible to scale these systems up to levels needed for commercial use."
While producing hydrogen from sewage, this system also cleans the water. Treatment plants could be developed that take in sewage at one end and send clean water and hydrogen fuel out the other.
Other forms of biowaste, including woody waste, could also be used.