Preparation of High Quality Bagasse Pulp by Using the ASAM Process

摘要

Bagasse was cooked by using the alkaline sulfite anthraquinone methanol (ASAM) process. Some pulping parameters were investigated and optimized to obtain pulps with low kappa number at high yield and viscosity. NaOH or Na_2CO_3 or both alkalis can be used as supporting alkali. The optimum methanol charge depends on the type of the supporting alkali. It was 15% for ASAM Ⅰ and 20% for ASAM Ⅱ and ASAM Ⅲ. The delignification process can be extended to 120 or 150 min (in dependence on the supporting alkali), without considerable degradation of the carbohydrates. 16 and 18% chemical charges and 0.7 alkali ratio are optimum conditions. Unbleached ASAM pulps possess high brightness (49-62% ISO). Papermaking properties of unbleached ASAM pulps were investigated at different beating times. ASAM pulps have 7998 - 9090 m breaking length, 43 - 48 burst factor, 78 -104 tear factor and are observed to be superior to kraft bagasse pulp.