Kraft Green Liquor Pretreatment of Softwood Chips. Part III: Lignin Chemical Modifications
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W. Ban
Summary
Quantitative 31P NMR analysis of residual lignin structures isolated from pulps pretreated by green liquor (GL) as a function of various operating parameters are discussed. Uncondensed phenolics and condensed hydroxyl groups decreased as the GL charge increased, but increased with increasing pretreatment temperature. During the cooking of pulps employing variable sulfidities and the addition of anthraquinone (AQ) or polysulfide (PS), various hydroxyl groups exhibited no obvious differences in the case of AQ addition, but dramatic changes were observed at variable sulfidities when the PS was used. The results implied that PS can exert a stronger catalytic effect under a higher sulfidity and result in more cleavage of the lignin macrostructure. The results also demonstrated a correlation between the nature of residual lignin and the efficiency of oxygen delignification based on the finding that the residual lignin in GL modified pulp exhibited a higher reactivity toward oxygen delignification.
Copyright © 2003 by Walter de Gruyter GmbH & Co. KG
Articles in the same Issue
- Editorial
- Post-Harvest Chemical Staining in Blackwood (Acacia melanoxylon R. Br.)
- Albino Strains of Ophiostoma Species for Biological Control of Sapstaining Fungi
- Presence of a Distinct S3 Layer in Mild Compression Wood Tracheids of Pinus radiata
- A Method to Estimate Fibre Length Distribution in Conifers Based on Wood Samples from Increment Cores
- Inhomogeneities in the Chemical Structure of Hardwood Lignins
- Molecular Modeling of Lignin β-O-4 Model Compounds. Comparative Study of the Computed and Experimental Conformational Properties for a Guaiacyl β-O-4 Dimer
- Kraft Green Liquor Pretreatment of Softwood Chips. Part III: Lignin Chemical Modifications
- The Role of Ferulic Acid Removal during Bleaching of Wheat Straw Mechanical Pulp with Peroxygen Reagents
- Surface Fractal Dimensionality and Hygroscopicity for Heated Wood
- Evaluation of the Microclimate in a Stored Softwood Chip Pile for Biopulping
- Wettability of Heat-Treated Wood
- The Relationship between Longitudinal Growth Strain, Tree Form and Tension Wood at the Stem Periphery of Ten- to Eleven-Year-Old Eucalyptus globulus Labill.
- Effects of Thermal Conductivity Data on Accuracy of Modeling Heat Transfer in Wood
- Detection of the Fracture Path under Tensile Loads through in situ Tests in an ESEM Chamber
- Properties of Southern Pine Wood Impregnated with Styrene
- Takayoshi Higuchi 75 Years Old
- Literature Reports
Articles in the same Issue
- Editorial
- Post-Harvest Chemical Staining in Blackwood (Acacia melanoxylon R. Br.)
- Albino Strains of Ophiostoma Species for Biological Control of Sapstaining Fungi
- Presence of a Distinct S3 Layer in Mild Compression Wood Tracheids of Pinus radiata
- A Method to Estimate Fibre Length Distribution in Conifers Based on Wood Samples from Increment Cores
- Inhomogeneities in the Chemical Structure of Hardwood Lignins
- Molecular Modeling of Lignin β-O-4 Model Compounds. Comparative Study of the Computed and Experimental Conformational Properties for a Guaiacyl β-O-4 Dimer
- Kraft Green Liquor Pretreatment of Softwood Chips. Part III: Lignin Chemical Modifications
- The Role of Ferulic Acid Removal during Bleaching of Wheat Straw Mechanical Pulp with Peroxygen Reagents
- Surface Fractal Dimensionality and Hygroscopicity for Heated Wood
- Evaluation of the Microclimate in a Stored Softwood Chip Pile for Biopulping
- Wettability of Heat-Treated Wood
- The Relationship between Longitudinal Growth Strain, Tree Form and Tension Wood at the Stem Periphery of Ten- to Eleven-Year-Old Eucalyptus globulus Labill.
- Effects of Thermal Conductivity Data on Accuracy of Modeling Heat Transfer in Wood
- Detection of the Fracture Path under Tensile Loads through in situ Tests in an ESEM Chamber
- Properties of Southern Pine Wood Impregnated with Styrene
- Takayoshi Higuchi 75 Years Old
- Literature Reports
