ECF Conversion at SAPPI Fine Paper North America, Skowhegan, Maine, 1999 Environmental Conference Proceedings

Douglas C. Pryke, Ray Hiltz, Tom Griffin, Dave Gallagher, Bertus Van Der Merwe--In July 1997, Sappi Fine Paper North America, Skowhegan, Maine, converted the bleaching process at their pulp and paper mill from 10% ClO2 substitution to ECF. The pulp mill bleaches hardwood at 17 kappa no. and softwood at 26 kappa no. on a campaign basis using a DEopDED sequence. The pulp mill produces approximately 450,000 tons per year at 89-90% ISO brightness for coated paper products.

An assessment of the conversion from 10% ClO 2 substitution to ECF for both hardwood and softwood pulp shows:

• Pulp quality was excellent; • Strength parameters were maintained;

• Hardwood brightness reversion and reversion variability decreased;

• Hardwood ionic trash and variability decreased; • The overall sequence Kappa factor for hardwood increased 23% and softwood 18%;

• Bleaching cost increased 25%;

Effluent properties improved substantially.

• 2,3,7,8-TCDD and 2,3,7,8-TCDF are not detected in bleach plant effluent;

• AOX decreased 80% to 0.3 kg/ADt;

• EPA’s list of polychlorinated phenols are not detected in bleach plant effluent at detection limits of 2.5-5 ppb;

• Chloroform in the bleach plant effluent declined 98% to < 0.5="" gm/adt;="" and="">

• Effluent color decreased 63%.

With conversion to ECF, the mill is in compliance with the recently released U.S. EPA “Cluster Rules” effluent guidelines, the State of Maine’s 1998 and 1999 bleach plant effluent dioxin and furan standards, and Maine’s 2001 final effluent color standard.