Soda-AQ pulping of reed canary grass

Delignification of reed canary grass (Phalaris arundinacea L.) was carried out by conventional soda-anthraquinone (AQ) pulping under varying conditions selected according to an orthogonal experimental design with four factors (cooking parameters) at three levels each L-9 (3(4)). The influence of these four parameters, i.e. effective alkali, EA (12, 15, and 18% on oven dried (o.d.) reed, as NaOH), maximum temperature (145, 155, and 165 degreesC), time to maximum temperature (70, 90, and 110 min), and time at maximum temperature (0, 15, and 30 min) on the pulp properties (yield, kappa number, and viscosity) was studied. Results indicated that, with respect to delignification, EA was the most important parameter, other parameters having a minor effect. It was also noted that, contrary to wood-based pulping, the viscosity of the reed canary grass pulp prepared in this study increased as the kappa number decreased. This finding might be explained by assuming that variations in hemicellulose content of the pulp resulted in the changes in viscosity, and that cellulose degradation was limited. (C) 2001 Elsevier Science B.V. All rights reserved.