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Cleaner Coal
Barring some science-fiction-type breakthrough, scientists
believe we're going to be dependent on fossil fuels to provide
energy for many years to come. However, that doesn't mean
we have to resign ourselves to high-polluting coal-fired power
plants. Omar M. Yaghi, Ph.D., professor of Chemistry and
Biochemistry, created a "new kind of chemistry," as he calls it,
that could dramatically reduce the carbon
dioxide that coal plants now release.
"It's a way to stitch molecules together
into extended networks to make porous
material," Yaghi says. These porous materials
can be designed to capture carbon dioxide
and store it like a reservoir. "No carbon
dioxide escapes. Nothing escapes unless you
want it to do so. We believe this is a turning
point in capturing carbon dioxide before it
reaches the atmosphere."
Yaghi's Center for Reticular Chemistry
has created new classes of materials with
weird-sounding names - ZIFs, COFs and
MOFs - that could solve a wide range of
problems. These "molecular sponges," as
Chemistry World magazine called them, have potential applications
ranging from selectively capturing carbon dioxide in
smokestacks to storing hydrogen as fuel for anything from
laptop computers to automobiles.
The most recent members of Yaghi's menagerie are zeolitic
imidazolate frameworks (ZIFs), which are porous crystalline
materials with a cage-like
structure. They work sort
of like a fishnet, letting
some materials in while
keeping others out.
Reticular chemistry
"allows us to design hundreds
of new structures"
where each of the components
are tailored for a specific
task, he says. "The
components of each structure
can be called a hub and
a strut, and the hubs are linked
with a strut to make extended
frameworks of any composition
and any functionality. So a
number of applications are now
being pursued that span all sectors
of the economy, from
health to petroleum refining to
renewable energy."
News of Yaghi's technology
spread rapidly after research
papers were published in several
leading journals, and "hundreds
of companies are very
interested in this chemistry," he says. His lab is working
closely with BASF, the global chemical company headquartered
in Germany, which partly funds his research at UCLA.
BASF is scaling up and marketing these compounds for various
uses, including the separation of gases and storage of
hydrogen and biofuels, as well as carbon dioxide capture. |
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