"The energy focus is currently on ethanol as a fuel, but economical ethanol from cellulose is 10 years down the road," says Bruce E. Logan, the Kappe professor of environmental engineering. "First you need to break cellulose down to sugars and then bacteria can convert them to ethanol."
Logan and Shaoan Cheng, research associate, suggest a method based on microbial fuel cells to convert cellulose and other biodegradable organic materials directly into hydrogen in today's (Nov. 12) issue of the Proceedings of the National Academy of Sciences online.
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.
Water hydrolysis, a standard method for producing hydrogen, is only 50 to 70 percent efficient. Even if the microbial electrolysis cell process is set up to bleed off some of the hydrogen to produce the added energy boost needed to sustain hydrogen production, the process still creates 144 percent more available energy than the electrical energy used to produce it.
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 range of efficiencies of hydrogen production based on electrical energy and energy in a variety of organic substances is between 63 and 82 percent. Both lactic acid and acetic acid achieve 82 percent, while unpretreated cellulose is 63 percent efficient. Glucose is 64 percent efficient.
Another potential use for microbial-electrolysis-cell produced hydrogen is in fertilizer manufacture. Currently fertilizer is produced in large factories and trucked to farms. 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.
Source: Penn State
Related stories:
How corals adapt to day and night
Researchers have uncovered a gene in corals that responds to day/night cycles, which provides some tantalizing clues into how symbiotic corals work together with their plankton partners.
Understanding Algae As An Alternative Fuel Source: Will The Real Algae X Please Stand Up
The recent creation of AXI, LLC is an alliance between Allied Minds, Inc. a seed investment company and the University of Washington. The alliance came about because of Professor Rose Ann Cattolico PhD, an algae-to-fuel expert. Professor Cattolico has been on the faculty and conducting algae research since 1975. Her research includes, chloroplast genome architecture and gene function in non-chlorophy b containing algae and functional genetic diversity within stramenopile population. Professor Cattolico has discovered a unique patented technology, she calls Algae X.
New process extracts pure hydrogen from contaminant in unrefined oil
A commercial-scale process to extract and reuse pure hydrogen from the hydrogen sulfide that naturally contaminates unrefined oil, including oil sands, is one step closer to reality thanks to a collaboration between the U.S. Department of Energy's Argonne National Laboratory and Kingston Process Metallurgy Inc. (KPM) of Kingston, Ontario.
Fuel cells: distant dream, but burning with promise
Some day, fuel cells may power your car and exhaust only water and perhaps carbon dioxide. More efficient and cleaner than an internal combustion engine, their emissions will be much lower. They may also run your home without the energy loss of power lines, or even power your laptop or cell phone. But not today or even tomorrow.
Power from Formic Acid
One of the central challenges of our time is the supply of enough environmentally friendly and resource-efficient energy to our society. In this context, hydrogen technology has taken on increased importance.
Scientists aim to boost world energy supplies -- with microbes
British and Canadian scientists expect to begin trials next month (May) to find out whether microbes can unlock the vast amount of energy trapped in the world's unrecoverable heavy oil deposits. An estimated six trillion barrels of oil remain underground because the oil has become either solid or too thick to be brought to the surface at economic cost by conventional means.
The price paid for higher energy is highly dangerous to teeth
For more than 10 years, energy drinks in the United States have been on the rise, promising consumers more “oomph” in their day. In fact, it is estimated that the energy drink market will hit $10 billion by 2010. While that may be great news for energy drink companies, it could mean a different story for the oral health of consumers who sometimes daily rely on these drinks for that extra boost.
Efficient Catalysts for Making Oxygen for 'Artificial Photosynthesis'
Scientists at the U.S. Department of Energy's Brookhaven National Laboratory and the Institute for Molecular Science in Japan are trying to mimic part of the complex natural process of photosynthesis with the goal of making non-polluting fuels such as hydrogen, for example, for use in fuel cells. In the March 10, 2008, web release of the journal
Inorganic Chemistry containing a Forum on "Making Oxygen," the scientists report they were able to mimic the "water oxidation catalysis" that occurs in natural photosynthesis.
