Modification of Egyptian Bagasse Kraft Pulping Using Yield - increasing Additives Ι-Effect on Chemical Properties

Abstract

BAGASSE is one of the potential raw materials for pulp in Egypt. So, our target is to improve the chemical properties of Kraft pulp using yield- increasing additives as anthraquinone (AQ), polysulfide (PS) and sodium borohydride (NaBH4). The effect of the bagasse to liquor ratio B/L ratio was also examined. The yield gains for AQ, PS, NaBH4, AQ-PS and AQ-NaBH4 were 4.73%, 6.46%, 2.99%, 12.15% and 4.05%, respectively for 1:4 B/L ratio. While the yield gains at 1:10 B/L ratio were 1.42%, 2.65%, 5.2%, 6.9% and 5.3%, respectively. Combination of AQ-PS gave synergistic effect. AQ, NaBH4 and AQ-NaBH4 reduced the kappa number by 7%, 14%, 9%, 4.48%, 40.3% and 5.95% for 1:4 and 1:10 B/L ratios, respectively. More dissolution of lignin was promoted at higher B/L ratio. All additives preserved the carbohydrate yield more than the Kraft one, and showed higher delignification selectivity except for PS.

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