Simultaneous obtaining of oxidized lignin and cellulosic pulp from steam-exploded sugarcane bagasse

Abstract Sugarcane bagasse was pretreated by steam explosion at 190 °C for 15 min and the resulting cellulignin was subjected to oxygen-assisted alkaline delignification in a 23 factorial design with three central points to investigate the effect of temperature, time and initial oxygen pressure on pulp yield, residual lignin content in the pulp and oxygen incorporation into the recovered lignin. Temperature and oxygen pressure had the greatest effect on the results, with optimal conditions resulting in a pulp yield of ∼41 % that contained residual lignin (3.7 %) and oxidized lignin with an oxygen content of 25 %. The procedure described here produces oxidized lignin with chelating properties and a cellulosic pulp with characteristics that favor pulp dissolution and easy bleaching in one additional step.