University Park, Pa.-Penn State University researchers have found that hydrogen as an everyday, environmentally friendly fuel source from cellulose and other biodegradable organic materials is closer than we think, and could be a method to produce fertilizer right on the farm. Bruce Logan, Kappe professor of environmental engineering, and research associate Shaoan Chang used a method based on microbial fuel cells to convert biodegradables directly into hydrogen. The researchers combined naturally occurring bacteria in a microbial electrolysis cell with acetic acid – the acid found in vinegar and the predominant acid produced by fermentation of glucose or cellulose. They used an anode of granulated graphite, a carbon cathode with a platinum catalyst, and 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,” said Logan. He and Chang believe that with microbial electrolysis cells, very large farms or farm cooperatives could produce hydrogen from wood chips, and then through a common process, use the nitrogen in the air to produce ammonia or nitric acid. Both of these are used directly as fertilizer – or the ammonia could be used to make ammonium nitrate, sulfate, or phosphate. The researchers have filed for a patent on this work, which was supported by Air Products and Chemicals Inc. and the National Science Foundation.
Transparency Across the Fertilizer Value-Chain