`Green' chemistry research project receives national award
Craig Hill, professor of chemistry, and visiting scientist Ira A. Weinstock,
a chemist at the U.S. Department of Agriculture (USDA) Forest Service Forest
Products Laboratory (FPL), received a national research award this summer
that recognized the excellence of their research group's results and the
group effort itself. The USDA Group Honor Award for Excellence they received
was for their work to create a process that has immediate industrial applications
to convert trees to paper without pollution.
"This award recognizes our group research efforts which led to the
issuing of patents that put us in a position to work with industry; we have
a strong, viable, promising product," said Hill. Only one of these
awards is given each year for research excellence within the USDA.
Nearly a dozen researchers are involved with the project, which has received
some $10 million in funding from the USDA, the U.S. Department of Energy
(DOE) and other sources over the past five years. Research team members,
located at Emory, the Forest Products Lab and the University of Wisconsin,
are developing a new approach to the bleaching and conversion of wood pulp
to paper. "Basically, we're creating a process that mimics biology,"
said Hill.
This new approach involves the use of inorganic mineral cluster compounds
called polyoxometalates (POMs). The first step of the technology involves
the direct oxidative degradation of wood pulp by the POMs to separate the
two major components of wood--lignin, which imparts the color, texture and
other properties to trees, and cellulose, which imparts the strength to
trees and paper and is the basis for most paper materials. The partially
oxidized and degraded lignin fragments and POMs are then filtered off, leaving
white cellulose that is ready to be made into paper. The lignin fragments
and POMs are then treated with air at high temperatures and pressures to
turn the POM back into its original form and convert all the waste products
from the bleaching step into carbon dioxide and water. The technology is
environmentally friendly in that it uses oxygen, not chlorine, as the oxidant,
uses only water as a solvent, produces no toxic organic compounds and generates
only carbon dioxide and water.
Weinstock, who is spending this year at Emory as a visiting scientist, was
a student at MIT when he first connected with Hill. "Craig gave a talk
when I was a grad student, and I knew of his work on creating enzyme analogs
that could be used in industry," said Weinstock. "In 1991 I wrote
to him to see if he would be interested in working on this project, and
he was."
Hill and Weinstock have received three patents on their work so far. "Now
the work is moving out of the lab and into industry," said Hill. "There
are members of an international consortium of pulp and paper companies that
are going to fund pilot-scale trials," said Hill. "Our recent
patents deal with the engineering process design of making our science work
for industry. This program has promise and has the full support of industry
and government."
"In 1991, the Forest Service took a risk on funding our project and
committed several of our FPL scientists to work on it," said Weinstock.
"This project is in line with the U.S. Forest Service's commitment
since its inception early in this centry to use national forests as a managed
resource, in addition to recreation. Additionally, the Department of Energy
has given major support for our work because they see it as a way to reduce
the paper industry's reliance on electricity in the paper making process."
Hill's and Weinstock's research is part of the "green" chemistry
movement, which emphasizes developing chemical processes in ways that are
more sustainable. "We have an industrial process that mimics a natural
process," said Hill. "Ours is a post-industrial vision, a sustainable
way to come at these products. Using nature as a paradigm of what's possible,
there are things we can do that nature can't do, because we have access
to catalysts and systems that aren't abundant in nature. We're combining
molecular science with something that's actually useful."
--Jan Gleason
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