Use of clean, carbon-neutral hydrogen on the horizonNovember 14th, 2007 - 10:39 am ICT by admin
“The energy focus is currently on ethanol as a fuel, but economical ethanol from cellulose is 10 years down the road,” claimed Bruce E. Logan, the Kappe professor of environmental engineering.
Logan and Shaoan Cheng, a research associate, suggest a method based on microbial fuel cells to convert cellulose and other biodegradable organic materials directly into hydrogen.
The researchers used naturally occurring bacteria in a microbial electrolysis cell with acetic acid - the acid found in vinegar.
Acetic acid is also the predominant acid produced by fermentation of glucose or cellulose. The anode was granulated graphite, the cathode was carbon with a platinum catalyst, and they used an off-the-shelf anion exchange membrane. The bacteria consume the acetic acid and release electrons and protons creating up to 0.3 volts. When more than 0.2 volts are added from an outside source, hydrogen gas bubbles up from the liquid.
“This process produces 288 percent more energy in hydrogen than the electrical energy that is added to the process,” says Logan.
For those who think that a hydrogen economy is far in the future, Logan suggests that hydrogen produced from cellulose and other renewable organic materials could be blended with natural gas for use in natural gas vehicles.
“We drive a lot of vehicles on natural gas already. Natural gas is essentially methane,” says Logan. “Methane burns fairly cleanly, but if we add hydrogen, it burns even more cleanly and works fine in existing natural gas combustion vehicles.”
The study appears in today’s issue of the Proceedings of the National Academy of Sciences online.
The researchers have filed for a patent on this work. Air Products and Chemicals, Inc. and the National Science Foundation supported this work. (ANI)
Tags: acetic acid, bacteria, bruce e logan, burns, carbon neutral, cellulose, electrolysis cell, ethanol, kappe professor, methane, microbial, national academy of sciences, natural gas combustion, natural gas vehicles, neutral hydrogen, organic materials, platinum catalyston exchange, proceedings of the national academy of sciences, volts