Researchers turn algae into high-temperature hydrogen source

Nov 12, 2009
This image shows the process by which Photosystem I in thermophilic blue-green algae can be catalyzed by platinum to produce a sustainable source of hydrogen. The system was highlighted in a paper by University of Tennessee, Knoxville research Barry Bruce, et al. in Nature Nanotechnology. Credit: Barry D. Bruce/University of Tennessee, Knoxville

In the quest to make hydrogen as a clean alternative fuel source, researchers have been stymied about how to create usable hydrogen that is clean and sustainable without relying on an intensive, high-energy process that outweighs the benefits of not using petroleum to power vehicles.

New findings from a team of researchers from the University of Tennessee, Knoxville, and Oak Ridge National Laboratory, however, show that - the process by which plants regenerate using energy from the sun - may function as that clean, sustainable source of .

The team, led by Barry Bruce, a professor of biochemistry and cellular and molecular biology at UT Knoxville, found that the inner machinery of photosynthesis can be isolated from certain and, when coupled with a , is able to produce a steady supply of hydrogen when exposed to light.

The findings are outlined in this week's issue of the journal Nature Nanotechnology.

Bruce, who serves as the associate director for UT Knoxville's Sustainable Energy and Education Research Center, notes that we already get most of our energy from photosynthesis, albeit indirectly.

The fossil fuels of today were once, millions of years ago, energy-rich plant matter whose growth also was supported by the sun via the process of photosynthesis. There have been efforts to shorten this process, namely through the creation of biomass fuels that harvest plants and covert their hydrocarbons into ethanol or biodiesel.

"Biofuel as many people think of it now -- harvesting plants and converting their woody material into sugars which get distilled into combustible liquids -- probably cannot replace gasoline as a major source of fuel," said Bruce. "We found that our process is more direct and has the potential to create a much larger quantity of fuel using much less energy, which has a wide range of benefits."

A major benefit of Bruce's method is that it cuts out two key middlemen in the process of using plants' solar conversion abilities. The first middle man is the time required for a plant to capture solar energy, grow and reproduce, then die and eventually become fossil fuel. The second middle man is energy, in this case the substantial amount of required to cultivate, harvest and process plant material into . Bypassing these two options and directly using the plant or algae's built-in solar system to create clean fuel can be a major step forward.

Other scientists have studied the possibility of using photosynthesis as a hydrogen source, but have not yet found a way to make the reaction occur efficiently at the high temperatures that would exist in a large system designed to harness sunlight.

Bruce and his colleagues found that by starting with a thermophilic blue-green algae, which favors warmer temperatures, they could sustain the reaction at temperatures as high as 55 degrees C, or 131 degrees F. That is roughly the temperature in arid deserts with high solar irradiation, where the process would be most productive. They also found the process was more than 10 times more efficient as the temperature increased.

"As both a dean and a chemist, I am very impressed with this recent work by Professor Bruce and his colleagues," said Bruce Bursten, dean of UT Knoxville's College of Arts and Sciences. "Hydrogen has the potential to be the cleanest fuel alternative to petroleum, with no greenhouse gas production, and we need new innovations that allow for hydrogen to be readily produced from non-hydrocarbon sources. Professor Bruce and his team have provided a superb example of how excellence in basic research can contribute significantly to technological and societal advances."

Source: University of Tennessee at Knoxville

Explore further: A new way to convert light to electrical energy

add to favorites email to friend print save as pdf

Related Stories

Renewable hydrogen energy - an answer to the energy crisis

Apr 19, 2007

Harvesting solar energy to produce renewable, carbon free and cost effective hydrogen as an alternative energy source is the focus of a new £4.2 million research programme at Imperial College London, it is announced.

Engineering algae to make fuel instead of sugar

Dec 17, 2008

In pursuing cleaner energy there is such a thing as being too green. Unicellular microalgae, for instance, can be considered too green. In a paper in a special energy issue of Optics Express, the Optical Society's (OSA) ...

Green diesel: New process makes fuel from plants

Jun 03, 2005

College of Engineering researchers have discovered a new way to make a diesel-like liquid fuel from carbohydrates commonly found in plants. Reporting in the June 3 issue of the Journal Science, Steenbock ...

Clemson research could help turn hydrogen hype into 'hy'ways

Feb 17, 2005

Americans will have a hard time driving on the future's highways if they don't have fuel. While hydrogen is the most abundant element in the universe, it's not readily available. Many researchers are working to develop fuel ...

Recommended for you

A new way to convert light to electrical energy

11 hours ago

The conversion of optical power to an electrical potential is of general interest for energy applications, and is typically accomplished by optical excitation of semiconductor materials. A research team has developed a new ...

Gold nanoparticle chains confine light to the nanoscale

Oct 29, 2014

A multidisciplinary team at the Centre d'Elaboration de Matériaux et d'Etudes Structurales (CEMES, CNRS), working in collaboration with physicists in Singapore and chemists in Bristol (UK), have shown that ...

Self-assembly of layered membranes

Oct 28, 2014

Techniques for creating complex nanostructured materials through self-assembly of molecules have grown increasingly sophisticated. But carrying these techniques to the biological realm has been problematic. ...

User comments : 5

Adjust slider to filter visible comments by rank

Display comments: newest first

powercosmic
3.8 / 5 (4) Nov 12, 2009
"New findings" show how algae "May be used"

WTF? What the hell sort of story and reporting is this?

Look, all this sort of pie in the sky reporting doesn't help. This story doesn't say if the paper provides pure hypothesis or direct, reproducible, lab work.

This is sloppy and lame reporting.
nrdufour
3.5 / 5 (2) Nov 12, 2009
Or it might be sloppy reading ;) The article talks about multiple experiments at different temperatures.
nrdufour
5 / 5 (2) Nov 12, 2009
Funny that the body of this article is actually copied from here http://www.utk.ed...-source/ ;)
gmurphy
4 / 5 (1) Nov 12, 2009
More detail would be nice tho, in particular, how did they isolate the inner machinery of photosynthesis from the algae and how did they couple this machinery with a platinum catalyst?, that's the real meat of the issue
PinkElephant
not rated yet Nov 13, 2009
More detail would be nice tho, in particular, how did they isolate the inner machinery of photosynthesis from the algae and how did they couple this machinery with a platinum catalyst?, that's the real meat of the issue


Not to mention, how long this isolated photosynthetic complex lasts before it degrades and stops functioning, and needs to be replenished (and, how easy is it to recover/recycle the platinum involved.)

Plus, there's still the limitation of how much solar energy can be gathered per unit area. Fossil fuels had accumulated over hundreds of millions of years; to sustainably produce equivalent energy from sunlight in "real-time" in sufficient quantities to power even today's world-wide car fleet (never mind the much larger fleet in a few decades), one would have to utilize truly VAST tracts of land.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.