Pulping of sugar cane bagasse with acetic acid under atmospheric pressure

Pulping of bagasse with acetic acid under atmospheric pressure was studied and the effect of some parameters on pulp properties was investigated. The best delignification was achieved by using 0.1% HCl or 0.2% HBr with acetic acid for 4 hours. However, there was a better selectivity for delignification with HCl than with HBr. With HCl, the increase of acetic acid concentration from 80-92.5% improved the delignification process, whereas with HBr not less than 90% acetic acid had to be used. Impregnating bagasse in acetic acid before pulping led to deterioration of pulp properties. An alkaline extraction step E with NaOH before bleaching with H2O2 reduced hydrolysis of the carbohydrates, consumption of H2O2 during bleaching and increased the brightness of the pulps. The effectiveness of this step was more pronounced when in pulping the concentration of acetic acid decreased and HBr was the catalyst. However, the impregnation step had negative effects on the action of NaOH in the E step. Unbleached and bleached pulps had 3.2 km and 3.8 km breaking length, 13.4 and 16.7 burst factor, 22.5 and 31.5 tear factor respectively.