Solar leaf that
converts CO2 into fuel
Carbon dioxide can
remove the greenhouse gas
from the atmosphere,
and provides a
sustainable type
of fuel.
All that is needed
now is to
remove the waste,
hot air
from congress
to get this on the market.
Scientists flip
energy equation with solar leaf that converts CO2 into fuel.
Researchers at the
University of Illinois at Chicago say the fuel from carbon dioxide can remove
the greenhouse gas from the atmosphere, and provides a sustainable type of fuel
that is as cheap as a gallon of gas.
By Ben Rosen, Staff
August 1, 2016
Courtesy of
University of Illinois at Chicago
It’s often smarter
to borrow from nature than reinvent the wheel.
That was the
approach of researchers at the University of Illinois at Chicago (UIC)
to remove carbon
dioxide (CO2 ) from the atmosphere, and convert it into an efficient,
inexpensive fuel.
The result:
an artificial leaf
that turns CO2 into fuel, "at a cost comparable to a gallon of
gasoline"
could render fossil
fuel obsolete, according to the researchers.
The “leaf” is one of
a growing number of inventions that mimic photosynthesis to remove excess
carbon from the atmosphere, and convert it into new, sustainable forms of
energy to power our world.
“The new solar cell
is not photovoltaic — it’s
photosynthetic,” said Amin Salehi-Khojin, an assistant professor of
mechanical and industrial engineering at UIC and the study’s lead author, in a
statement. “Instead of producing energy in an unsustainable one-way route from
fossil fuels to greenhouse gas, we can now reverse the process and recycle
atmospheric carbon into fuel using sunlight.”
The solar cells Dr.
Salehi-Khojin and his team built function like a plant’s leaves. Except instead
of converting carbon dioxide into sugar, the artificial leaf converts the
gaseous compound into synthesis gas — a mixture of hydrogen and carbon
monoxide. Synthesis gas, or syngas, could be burned for fuel, or converted into
diesel or other hydrocarbon fuels.
The concept of
reduction reaction — converting CO2 into a burnable form of carbon —
isn’t new. But scientists previously relied on silver and other expensive
precious metals to break gas into storable energy. UIC researchers took a
different approach. They relied on a nano-structured compound, a transition
metal dichalcogenide (TMCD), to break down carbon dioxide. They paired a kind
of TMCD — a nanoflake tungsten — with an ionic liquid inside a two-compartment,
three-electrode electrochemical cell.
When light strikes
the "leaf," hydrogen and carbon monoxide bubble from the cathode,
while free oxygen and hydrogen ions are released from the anode.
Leafs could be
spread throughout a solar farm, or used in smaller applications, the
researchers said.
The invention isn’t
the only one of late to use the concept of photosynthesis to create a new form
of energy. The researchers note the process they employed has been used to
create other forms of hydrogen energy. Researchers at Harvard University have
even created hydrogen through synthetic photosynthesis in a process they say is
10
times more efficient than in nature, as The Christian Science Monitor’s
Jason Thomson reported in June.
That process relies
on bacteria. The system is confined to a jar with just two electrodes,
Ralstonia eutropha bacteria, and water. When an electric current passes through
the electrodes, it breaks the water molecules down, releasing hydrogen gas.
“You can use
hydrogen as a source of energy, [and] burn it,” co-author Pamela Silver of
Harvard University told the Monitor. “Instead, we decided to take advantage of
bacteria that take in hydrogen and carbon dioxide and use them to grow.”
As they grow,
explains Dr. Silver, these organisms produce certain compounds. The bacteria
can be genetically engineered to make useful things like alcohol and plastic
precursors.
While the artificial
leaf UIC researchers invented is just artificial, not bionic, it’s
applicability isn’t confined to this world. They note it can even be used if
water is found on Mars. Mars’s atmosphere is mostly CO2 , after all.