The origins of kraft wood fibre surface lignin were investigated. Results showed that the primary source of the enriched fibre surface lignin was the deposition of dissolved lignin back on the fibre surface from the spent pulping liquor. The remaining of middle lamella material had minimal effect on fibre surface lignin enrichment. The effectiveness of three novel catalysts in enhancing oxygen delignification was studied. Bleaching experiments were performed on a mill-produced hardwood kraft pulp under acidic conditions.
Various additives can control fireside deposit accumulation in recovery boilers.
The cleaning radius of a sootblower at any location in a recovery boiler can be estimated if the temperature dependence of deposit physical properties and the operating characteristics of the sootblower are known.