A comparison of soda and soda-AQ pulps from cotton stalks

In this study, cotton stalks (Gossypium hirsutum L.) were cooked using soda and soda-anthraquinone (AQ) process. Nine soda cooks were conducted by changing cooking conditions including active alkali charge and pulping time. Soda-AQ cooks were obtained by adding 0.075, 0.10, 0.15, 0.2% AQ (based on o.d stalks) to optimum soda pulping. Adding AQ to soda pulps led to the increase in regarding to pulp yield and kappa numbers. On the other hand, soda-AQ pulps made from cotton stalks showed higher mechanical properties than soda pulps. The results indicated a major increase in pulp brightness when soda pulping was modified with %0.15 AQ. Also, the results showed that better pulp and paper can be produced from cotton stalks by soda-AQ process compared to the soda process.