Effect of prehydrolysis on pulping and bleaching of Acacia auriculiformis A. Cunn. ex Benth.

Prehydrolysis prior to pulping shows a beneficial effect in subsequent delignification and bleaching. Prehydrolysis of Acacia auriculiformis produced higher pulp yield in soda and soda-anthraquinone processes at similar kappa number than non-prehydrolyzed kraft process. In D 0 E p D 1 bleaching sequences, delignification (DoEp kappa) and bleachability were better for prehydrolyzed A. auriculiformis pulp in the pulping processes studied. The lignin from prehydrolyzed wood chips was characterized with lower molecular weight and slightly higher phenolic hydroxyl group. This suggested the depolymerization of lignin in prehydrolysis process.