Enhanced Delignification Selectivity of Alkali-Oxygen Pulping by Wet-Storage Pretreatment with Bleaching Wastewater

Wet-storage is the most common way to maintain sugarcane bagasse in the pulping and paper-making industry, although there are few studies focused on the selectivity of delignification in pulping for bagasse treated by wet-storage. In this study, wet-storage of bagasse was carried out before alkali-oxygen pulping. The influence of wet-storage pretreatment on the chemical compositions, morphology of bagasse, and the consumption of NaOH in alkali impregnated bagasse meal were investigated. The wet-storage of bagasse resulted in significant improvement in delignification selectivity of alkali-oxygen pulping. After the bagasse was pretreated by wet-storage with bleaching water, the screened yield and crystallinity of the resulting alkali-oxygen pulp were increased.