1. 1 Kraft Pulping Kinetics: Initial Phase

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3. 3 Kraft Pulping Kinetics: Bulk Phase

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5. 5 Kraft Pulping Kinetics: Residual Phase

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7. 7 Kraft Pulping Kinetics: In “Nutshell” PhaseLigninCarbohydrateAlkali Initial Rapid delignification Indep. of [OH-] and [HS-] Rapid carbohydrate degradation Some [OH-] dependence Indep.of [HS-] Rapid alkali consumption Bulk Moderate delignification rate Dep. on [OH-] and [HS-] Moderate carbohydrate degradation Moderate consumption of alkali

8. 8 Kraft Pulping Kinetics: In “Nutshell” PhaseLigninCarbohydrateAlkali Residual Very slow delignification Some dep. on [OH-] and ? [HS-] Substantial carbohydrate degradation – especially viscosity Re-deposition of Xylans Some alkali consumption