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Goldman explained that the breakthrough technology
employs a pair of catalytic chemical reactions that operate in tandem,
one of which captured the 2005 Nobel Prize in Chemistry. This dynamic
chemical duo revamps the Fischer-Tropsch (FT) process for generating
synthetic petroleum substitutes, invented in 1920 but never developed
to the point of becoming commercially viable for coal conversion.
The FT process recently gained national attention
through the efforts of Brian Schweitzer, governor of coal-rich
Montana, who has been publicly extolling the potential of
Fischer-Tropsch. The Goldman group's innovations eliminate
shortcomings in the process that can finally make it a workable
solution to dwindling domestic oil reserves.
"The key to energy independence in the next five
decades is Fischer-Tropsch chemistry, amended and enhanced," said
Goldman, a professor in the department of chemistry and chemical
biology at Rutgers, The State University of New Jersey. "The study of
catalysts, the little molecular machines that control chemical
reactions, is my field. With our new catalysts, one can generate
productive, clean burning fuels with Fischer-Tropsch, economically and
at unsurpassed levels of efficiency."
This discovery is reported in the April 14, 2006 issue of
the journal Science by Goldman and his colleagues. The work grew out
of a National Science Foundation-funded research consortium, the
Center for the Activation and Transformation of Strong Bonds, based at
the University of Washington.
Fischer-Tropsch yields a wide distribution of
molecular weight hydrocarbon products but without any way to control
the desired mix. The molecular weight is the weight of a molecule of a
substance, or the sum of the weights of all atoms in the molecule. The
low-weight and the high-weight Fischer-Tropsch products are useful –
the light as gas and the medium-heavy as diesel fuel, Goldman
explained.
"The problem – the greatest inefficiency of the
process – is that you also wind up with a substantial quantity of
medium-weight products that are not useful and you are stuck with them,"
Goldman said. "What we are now able to do with our new catalysts is
something no one else has done before. We take all these undesirable
medium-weight substances and convert them to the useful higher- and
lower-weight products."
Technically, this is accomplished by a catalyst
that removes hydrogen from the molecules. This converts the
hydrocarbons to olefins, products with double bonds which are
necessary for the creation of the desirable, useful end-products. The
beauty of the new process is that it is highly selective in which
hydrogen atoms it removes from the hydrocarbons, channeling the
reactions to produce specific, useful products.
The researchers combined this process with the
action of a second catalyst, one which promotes olefin metathesis, for
which the 2005 Nobel Prize was awarded. Metathesis means "to change
places" and, here, the double-bonding atom groups change places with
one another. Through this reaction, the second catalyst rearranges the
molecular weight distribution of the olefins. The first catalyst then
replaces the hydrogen atoms onto the new rearranged olefins; this
returns the olefins back to their original hydrocarbon form, but now
with a new, more desirable weight distribution. |
