The physical, chemical, and morphological characteristics of Acacia auriculiformis were evaluated in terms of its suitability for papermaking. The fiber length ( mm) of A. auriculiformis in this study was within the range of tropical hardwoods. | Turk J Agric For 32 (2008) 339-347 © TÜB‹TAK Alkaline Pulping and Bleaching of Acacia auriculiformis Grown in Bangladesh M. Sarwar JAHAN1,*, Rowshan SABINA2, Arjumand RUBAIYAT2 1 Pulp and Paper Research Division, BCSIR Laboratories, Dhaka, Dr. Qudrat-I-Khuda Road, Dhaka-1205, BANGLADESH 2 Department of Applied Chemistry and Chemical Technology, Dhaka University, Dhaka, BANGLADESH Received: Abstract: The physical, chemical, and morphological characteristics of Acacia auriculiformis were evaluated in terms of its suitability for papermaking. The fiber length ( mm) of A. auriculiformis in this study was within the range of tropical hardwoods. The lignin content in A. auriculiformis was and α-cellulose , which was within the range of other acacias, but that of extractives was higher. Soda, soda-AQ, and kraft processes were studied in pulping. Screened pulp yield was increased with increasing active alkali. Acceptable pulp yield (43%-44%) and kappa number (22-24) were obtained at 20% alkali and h of cooking in soda, 16% alkali and h of cooking in soda-AQ, and 18% alkali in 2 h of cooking in kraft process. Soda-AQ pulp showed better strength properties than soda and kraft pulp. Soda, soda-AQ, and kraft pulps were bleached in DEpD and DEpDEpD (where D denotes Chlorine dioxide, E denotes peroxide reinforced alkaline extraction) bleaching in different kappa factors. In DEpD bleaching, kraft pulp showed better bleachability as compared to soda and soda-AQ pulp. However, in case of DEpDEpD bleaching, all pulps exhibited almost the same brightness. At the same kappa factor, final brightness of pulp increased from 72%-75% to 85%-86% with splitting DEpD and DEpDEpD sequences, respectively. Key Words: Acacia auriculiformis, pulp yield, kappa number, strength properties, bleachability, viscosity Introduction An ever-increasing demand for paper combined with a declining fiber supply from the forests of the world is forcing the pulp and paper .
