SODA PULPING OF MISCANTHUS-SINENSIS - EFFECTS OF OPERATIONAL VARIABLES ON PULP YIELD AND LIGNIN SOLUBILIZATION

A simple system for the production of alkaline pulps from Miscanthus s inensis was studied. Miscanthus sinensis is a non-woody plant species of rapid growth with reported yields of up to 40 t ha(-1) year(-1). A first-order full-factorial design was used to analyse and evaluate the effects of variables on pulp yield and lignin solubilization. The var iables studied and their respectives ranges of variation were as follo ws: liquid to solid ratio, 6-10; temperature, 80-100 degrees C; time, 0-240 min; NaOH concentration, 1-2%. Good pulp yields (about 60%) and acceptable values of residual lignin (less than 10%) were obtained in the best conditions, which meant a percentage lignin solubilization cl ose to 80%. This study also showed that selectivity of the system was independent of the working conditions and this could be summarized in the following formula: dissolved lignin/weight losses = 0.4. Copyright (C) 1996 Elsevier Science Ltd.