Anthraquinone polymer catalysts for alkaline delignification of lignocellulosic matter. Part 3. Delignification of softwood and action on a phenolic β-O-4 lignin model in kraft pulping conditions
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Emmanuel Cazeils
Abstract
The delignification action of four new anthraquinone (AQ) polystyrene catalysts – three of them linear (CP-A, CP-B, CP-C) and one cross-linked (CP-3D) – were investigated on softwood (Pinus pinaster) chips under kraft pulping conditions, and their catalytic efficiency gains (EGs) were compared to that of AQ, with EGAQ=100. The catalytic EG of the hydrophobic polymers CP-B and CP-3D was 96%, while the inherent hydrophilic catalyst CP-C showed an EG of 30%. Interpretation: hydrogen sulfide anions presented in the kraft pulp liquor might participate in the delignification mechanisms as redox active mediators in the case of the hydrophobic polymers. Moreover, the latter could be recovered after pulping, and delignification tests with the recovered materials revealed that they preserved their catalytic properties. Mechanistic studies were carried out with a phenolic β-O-4 lignin model compound in the presence or absence of glucose (mimicking the carbohydrate end groups) and/or NaSH. It was shown that the cross-linked CP-3D polymer reacted with the lignin model through electron transfer reactions, a process most likely mediated by glucose and HS- redox active species. The concept of grafting AQ into polymeric substrates is discussed in terms of reusable delignification catalysts for large-scale pulping processes under kraft conditions.
©2012 by Walter de Gruyter Berlin Boston
Articles in the same Issue
- Masthead
- Masthead
- Original Papers
- Anthraquinone polymer catalysts for alkaline delignification of lignocellulosic matter. Part 1. Syntheses and characterizations
- Anthraquinone polymer catalysts for alkaline delignification of lignocellulosic matter. Part 2. Action in soda pulping conditions on softwood and phenolic β-O-4 lignin models
- Anthraquinone polymer catalysts for alkaline delignification of lignocellulosic matter. Part 3. Delignification of softwood and action on a phenolic β-O-4 lignin model in kraft pulping conditions
- Analysis of fibre deformation processes in high-consistency refining based on Raman microscopy and X-ray diffraction
- Distribution of wood polymers within the cell wall of transgenic aspen imaged by Raman microscopy
- Chemical improvement of surfaces. Part 2: Permanent hydrophobization of wood by covalently bonded fluoroorganyl substituents
- Testing of the superhydrophobicity of a zinc oxide nanorod array coating on wood surface prepared by hydrothermal treatment
- Properties of molding plates made with albizia wood particles impregnated with alcohol-soluble PF resins prepared from phenol-liquefied lignins
- Within-ring movement of free water in dehydrating Norway spruce sapwood visualized by neutron radiography
- Influence of hygromechanical history on the longitudinal mechanosorptive creep of wood
- Effects of systematic variation of wood adherend bending stiffness on fracture properties: Part 1. Influence of grain angle
- Effects of systematic variation of wood adherend bending stiffness on fracture properties. Part 2. Revisiting traditional DCB analysis methods
- Determination of adhesive energy at the wood cell-wall/UF interface by nanoindentation (NI)
- Short Notes
- Distribution of extracts including 4,8-dihydroxy-5-methoxy-2-naphthaldehyde in Diospyros kaki analyzed by gas chromatography-mass spectrometry and time-of-flight secondary ion mass spectrometry
- Southern pine impregnated with silicate solution containing cellulose nanofibrils
- Meetings
- Meetings
Articles in the same Issue
- Masthead
- Masthead
- Original Papers
- Anthraquinone polymer catalysts for alkaline delignification of lignocellulosic matter. Part 1. Syntheses and characterizations
- Anthraquinone polymer catalysts for alkaline delignification of lignocellulosic matter. Part 2. Action in soda pulping conditions on softwood and phenolic β-O-4 lignin models
- Anthraquinone polymer catalysts for alkaline delignification of lignocellulosic matter. Part 3. Delignification of softwood and action on a phenolic β-O-4 lignin model in kraft pulping conditions
- Analysis of fibre deformation processes in high-consistency refining based on Raman microscopy and X-ray diffraction
- Distribution of wood polymers within the cell wall of transgenic aspen imaged by Raman microscopy
- Chemical improvement of surfaces. Part 2: Permanent hydrophobization of wood by covalently bonded fluoroorganyl substituents
- Testing of the superhydrophobicity of a zinc oxide nanorod array coating on wood surface prepared by hydrothermal treatment
- Properties of molding plates made with albizia wood particles impregnated with alcohol-soluble PF resins prepared from phenol-liquefied lignins
- Within-ring movement of free water in dehydrating Norway spruce sapwood visualized by neutron radiography
- Influence of hygromechanical history on the longitudinal mechanosorptive creep of wood
- Effects of systematic variation of wood adherend bending stiffness on fracture properties: Part 1. Influence of grain angle
- Effects of systematic variation of wood adherend bending stiffness on fracture properties. Part 2. Revisiting traditional DCB analysis methods
- Determination of adhesive energy at the wood cell-wall/UF interface by nanoindentation (NI)
- Short Notes
- Distribution of extracts including 4,8-dihydroxy-5-methoxy-2-naphthaldehyde in Diospyros kaki analyzed by gas chromatography-mass spectrometry and time-of-flight secondary ion mass spectrometry
- Southern pine impregnated with silicate solution containing cellulose nanofibrils
- Meetings
- Meetings
