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INDUSTRIAL TECHNOLOGIES PROGRAM

Nation

Allows more recycled fiber to be used

consumption and increasing the value of recycled paper products.

Reduction in operational costs of recycling mills

Major cost savings for stickies-control chemicals

j

•

•

•

With Mechanical Alternatives

during processing.

they lose their tack and become benign.

Boosting the productivity and competitiveness of U.S. industry through improvements and environmental performance

Benefits for Our Industry and Our

in papermaking, reducing energy

Applications in Our Nation’s Industry

Almost half of the content of the paper produced in the United States is recycled. The results of this pro ect will inform the development of recycling processes that benefit the large number of paper mills that use recycled fiber.

Replacing Chemicals in Recycle Mills

Mechanical Shock Waves Will Be Substituted for Chemicals in Pulp and Paper Recycling Operations

Wax and other sticky contaminants cause considerable downtime in mills utilizing secondary fiber, and several million dollars’ worth of minerals and polymers are added for handling and detackifying these “stickies”

A promising method for achieving the same result through mechanical means is the use of

pulsed power technology to deliver a shock wave to the pulp slurry. When a spark is discharged under water, it creates a plasma, which sets up a shock wave that also generates reactive hydroxyl radicals by splitting water. The shock wave can potentially be used to disperse stickies, while the hydroxyl radicals are able to oxidize stickies to the extent that

The photograph shows the effect of the shock wave on air bubbles in water.

INDUSTRIAL TECHNOLOGIES PROGRAM

Project Description

Goal: To study the feasibility and economics of applying pulsed power technology to the pulp and paper industry through two initial applications.

The two objectives to this research in the forest products industry were as follows:

1) Dispersion of stickies in whitewater systems. Researchers induced agglomeration of stickies and measure its rate, using two model stickies: a hot melt (polyvinyl acetate) and a pressure-sensitive adhesive (acrylate).

2) Detackification of stickies. Studies examined the potential detackification of stickies through energetic chemical species created by the shock wave. Shock waves were applied, and the detackification of stickies examined as a function of pulse energy and other parameters. Suspensions in water and in pulp slurries were also examined to determine the pulse level required for optimum detackification.

The laboratory-scale work of this two-year project was conducted at the Institute of Paper Science and Technology. Field work was carried out at commercial mills.

The success of this project resulted in federal support of field testing in a second phase, titled “Decontamination of Process Strams Through Electrohydraulic Discharge.”

Results

• A full-scale trial, run for five weeks in April/May 2000 at Visy Paper, Conyers, GA, showed that a single sparker unit placed in the stuff box was able to reduce stickies deposition on the dryer felts.

• Both sonication and sparking create hydroxyl radicals. Since both processes also detackify stickies, it is likely that hydroxyl radicals are responsible for the detackification

• Sparking caused a decrease in the tack of the deposits in one case, while lower bleach use occurred in two other mills. Sparking reduced the degree of ink reattachment to fiber.

• At one mill, sparking induced deposition of contaminants, which is a positive development if it can be controlled. The technique is also able to degas water and to oxidize odor-causing sulfur compounds.

• Second-order effects caused by the technology need to be defined further before the technology can be broadly applied.

Commercialization

This project resulted in the filing of a patent application and the negotiation of a licensing agreement with Spartec Environmental, Ontario.

Project Partners Sparktec Environmental Hamilton, Ontario Canada

Visy Paper, Inc Conyers, GA

For additional information, please contact

Drew Ronneberg, Ph.D. Industrial Technologies Program Phone: (202) 586-0205 Fax: (202) 586-9234 E-mail: Drew.Ronneberg@ee.doe.gov

Sujit Banerjee, Ph.D. Institute of Paper Science and Technology Phone: (404) 894-9709 Fax: (404) 894-4778 E-mail: s.banerjee@ipst.edu

A Strong Energy Portfolio for a Strong America Energy efficiency and clean, renewable energy will mean a stronger economy, a cleaner environment, and greater energy independence for America. Working with a wide array of state, community, industry, and university partners, the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy invests in a diverse portfolio of energy technologies.

January 2007 Project completed by June 2002 Full award # DE-FC36-99GO10381

For more information, visit www.eere.energy.gov/industry or call 1-877-337-3463