ABSTRACT
The present work evaluated different alkaline pulping conditions for Eucalyptus saligna wood. The objective was to evaluate the influence of the anthraquinone (AQ) on the reduction of the total reduced sulfur (TRS) in the aerial emissions, by reducing the sulfidity. The experiment consisted of 8 cooking with active alkali varying from 19 to 21%, sulfidity from 0 to 20% and anthraquinone from 0 to 0.1%, aiming to obtain kappa numbers in the range 15.5±1.5. The H factor was used to control the relation time/temperature along cooking. The addition of anthraquinone increased the delignification rate allowing sulfidity reduction. The kraft/AQ pulping with sulfidities of 5 and 10% presented satisfactory results, making it possible the replacement of conventional kraft cooking, giving a reduction in process sulfidity without harms in pulping. In spite of a slightly lower performance, the soda/AQ cooking has potential to be used where the smell is a critical problem in the industrial operation.
Key words:
anthraquinone; sulphidity; alkaline pulping; Eucalyptus saligna