Alkaline pulping with additives of kenaf from Sudan

Soda-anthraquinone (soda-AQ), alkaline sulfite-anthraquinone (AS-AQ) and ASAM (alkaline sulfite-anthraquinone-methanol) cooking of kenaf core, bark and whole stalk from Sudan was carried out under different conditions and pulps with good to very good yields and mechanical properties were obtained. The AS-AQ process was particularly well suited for kenaf whole stalk and bark with yield, viscosity, brightness and strength properties superior to those of soda and soda-AQ pulping. ASAM pulping provided a further selective delignification with higher yield, lower K number and superior viscosity and brightness at high pulp strength level. Blending 90 and 70% kenaf core pulp with pulp from kenaf bark improved all the strength and optical properties, with the 70% blends better. The application of a totally chlorine free (TCF) bleaching sequence of OQ(1)(PO)Q(2)P on whole kenaf stalk soda AQ and ASAM pulps gave pulp very high brightness and strength properties. (C) 2002 Elsevier Science B.V. All rights reserved.