[GRRN] Fw: New Paper Bleaching Technology

Bill Sheehan (zerowaste@grrn.org)
Sat, 26 Jun 1999 06:15:00 -0400

----- Original Message -----
From: Billy Stern <billysun@wildrockies.org>

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NEWS for all interested in CLEAN pulp and paper PRODUCTION
FEATURING news, analysis, resources and contacts


A recent article in the Pittsburgh Post-Gazette offered an example of the
rapidly advancing technology that will allow the pulp industry to meet
stringent environmental standards in a cost effective manner.

Terry Collins, a chemist at Carnegie Mellon University, has found a way to
improve the bleaching power of hydrogen peroxide. Collins' research team
has developed catalysts that activate hydrogen peroxide and focus the
reaction on particular targets.

One version of the catalyst would greatly improve the abilities of hydrogen
peroxide in the bleaching process at wood pulping mills, helping to
eliminate the chlorine-based bleaches that result in the production of
dioxins and other organochlorines. Another catalyst might be used as a
laundry bleach activator. Collins hopes the activated hydrogen peroxide
might one day be used to purify drinking water, clean up toxic spills and
improve any number of industrial processes that rely on oxidation.


To create strong, bright wood pulp, lignin must be removed from the wood.
Historically, the methods to do this have focused on chlorine-based
chemicals. But these agents also produce toxic by-products and a dark
effluent that turns rivers the color of Coca-Cola. Regulations around the
world are pressuring mills to move away from chlorine gas and sodium
hypochlorite. In British Columbia, all emissions of chlorinated wastes must
be eliminated from liquid effluent by the year 2002.

The best environmental method to bleach pulp has been the subject of
vigorous and sometimes acrimonious debate. Chlorine dioxide is one of the
most developed alternatives, but it is expensive and requires careful
handling. It also is corrosive, which would dash industry hopes to begin
recycling effluent within three to five years, according to Richard
Presley, an employee of Solvay Interox and recent Chairman of the TAPPI
Bleaching Section. Ozone-, oxygen- and hydrogen peroxide-based processes
are being used in advanced mills around the world. These methods continue
to require bleaching at high temperatures and pressures. While clearly cost
effective for greenfield mills, high initial capital investment has
frightened off many North American mills.

Collins' process, by contrast, works at normal temperatures and pressures,
is not corrosive, and requires no special handling. It requires no capital
investment and could be implemented for $2 -to-$3 million per mill, Presley

These developments indicate that we are closer than ever to reaching
totally chlorine free, closed loop pulp mills and that governments should
not retreat from the strong regulations that are driving these changes.

* Jay Ritchlin with sources from the Pittsburg Post-Gazette and
conversation with Terry Collins.
Mill-Watch is sponsored by Reach For Unbleached! Canada to connect
people and re-sources working on pulp and paper issues.

Delores Broten,
Reach for Unbleached! Foundation,
Box 39, Whaletown BC Canada V0P 1Z0
Ph/fax: (250) 935-6992