Forecasted Value Analysis for AQ and AQ/Polysulfide Pulping, 1995 Pulping Conference Proceedings

Gerry Katz Technical

Westvaco Corporation

Howard X. Deal

BE&K Engineering

James A Durkee

Westvaco Corporation

W. Rhett Smith

Westvaco Corporation

The use of anthraquinone (AQ) as a pulping additive is expanding at a rapid rate in North America. The addition of polysulfide to AQ pulping is being evaluated by several mills. These additive pulping technologies offer approaches for pulp yield selectivity that are not available by other pulping methods. However, the methodology for calculation of the forecasted value of implementing these technologies is not yet established. This paper presents the development of an economic model that can be used to determine the implications in the digester, recovery and bleach plant areas for the stepwise implementation of these new additive pulping technologies. Several operating cases are studied, including increased bleached pulp production for recovery limited operation, and for digester limited operation. The impact of increased wood costs is determined for the base case. Then the operating cases are calculated for recovery limited, digester limited, and production limited. Bleached pulp cases are applicable for hardwood and softwood pulping. The unbleached pulp case is applicable for softwood. The pulp production can be valued for a variety of products including bleached market pulp, uncoated fine paper, coated fine paper, and bleached board. For unbleached pulp the product is valued as linerboard. The model allows calculation of the impact of installation of these technologies into a base case operating system. The model calculates the impact on pulping, recovery, evaporation, causticizing, and bleaching. The overall economic impact on the total mill operation is projected using a Profit & Loss balance, in which estimated variations in cost or revenues are assumed to impact the bottom line of the P & L.