STUDY ON THE ADDITIVES DURING SODA-AQ COOKING OF COTTON STALK

摘要

Soda-AQ cooking of whole cotton stalk with different additives was carried out in this paper. Alkaline lignin isolated from the black liquor of cotton stalk soda-AQ cooking was modified by purification and sulfonation and was used as cooking additive. The cooking effects with Nekal powder BX, lignin sulfonate, sodium oxalate and alkyl fatty alcohol polyethylene oxide (JFC) were compared. Better cooking effect was gained by adding formaldehyde and sodium sulfite during cotton stalk cooking. The pulp quality of soda-AQ cooking was effectively improved by adding 1.0% formaldehyde, 1.0% sodium sulfite and 0.2% lignin sulfonate. At this cooking condition, pulp yield increased 4.7%, pulp brightness increased 14.3%ISO and Kappa number decreased 7.72.