|
Oak
Ridge, TN --- April 19, 2005 --- Zhiyu Hu believes
it is possible to match nature's highly efficient
method to convert chemicals into thermal energy at
room temperature, and he has data and a published
paper to support his theory.
In
a paper scheduled to appear in the May 18 print
issue of the American Chemical Society's Energy & Fuels, Oak Ridge National
Laboratory's Hu describes a novel method to achieve
spontaneous ignition and sustained combustion at room
temperature. He achieves this "nano-catalytic
reaction" with nothing but nanometer-sized particles
of platinum stuck to fibers of glass wool in a small
jar with methanol and air – with no source of external
ignition.
Although this began
as little more than a curiosity, Hu quickly realized
that the implications could be significant because
of the potential gains in energy conversion and utilization.
Hu now cites possibilities in the area of distributed
power generation and perhaps military and homeland
defense.
While additional research
needs to be performed to understand the phenomena,
Hu notes that natural organisms such as microbes,
plants and animals obtain energy from oxidation of
the same organic chemicals at their physiological,
or body, temperatures. Many of these biological reactions
also use metals as part of their enzyme catalysts.
Still, this is a surprising result in the field of
metal catalysis.
"Since the caveman
days, we have burned things to utilize their energy,
and the high temperatures and the entire process have
created a lot of problems that we're then forced to
deal with," said Hu, a physicist in the Life
Sciences Division of the Department of Energy's ORNL.
Citing
the wisdom of one of the all-time great scientists,
Hu noted that Albert Einstein once said, "Problems cannot
be solved at the same level of awareness that created
them." So, according to Hu, the best way to
solve the energy crisis is to replace our existing
fuel consuming method with one that has much higher
efficiency and less environmental impact.
Indeed, there is room
for efficiency improvement, Hu said, noting that an
internal combustion engine is only about 21 percent
efficient. The process also creates environmental
concerns because of nitrogen oxide emissions that
form because of the high combustion temperatures.
Even an advanced fuel cell is only about 50 percent
efficient, and it must be operated at a temperature
that is much higher than our body or room temperature,
which requires costly components able to withstand
harsh conditions.
"What we have
is the possibility of retrieving energy at a lower
temperature with greater efficiency and lower environmental
effects," Hu said.
The
method outlined in the paper "Nano-catalytic spontaneous ignition
and self-supporting room-temperature combustion," co-written
by ORNL's Vassil Boiadjiev and Thomas Thundat, was
discovered unintentionally. Hu was actually conducting
another experiment with platinum particles, methanol
and cotton swabs when he noticed the mixture produced
smoke. He consulted with Thundat and others who encouraged
him to figure out what was happening.
"This wasn't
research that was funded, so I worked evenings and
weekends to try to understand why and how this happened," Hu
said. He replicated the discovery numerous times
under different conditions and noticed that the reactions
can reach high temperatures of greater than 600 degrees
Celsius and low temperatures of just a few tenths
of a degree above room temperature.
Hu also learned that
he can control the reaction by varying the fuel-air
mixture, and he discovered that the process can be
dramatically changed by reducing the particle size
and changing the particle's morphology, or shape.
Oak Ridge National
Laboratory is managed by UT-Battelle for the Department
of Energy.
Media Contact:
Ron Walli
Communications and External Relations
865.576.0226
|
