Handbook of Pulp. Volume 2. Edited by Herbert Sixta. WILEY- VCH WILEY-VCH Verlag GmbH & Co. KGaA

Transcription

1 Handbook of Pulp Volume 2 Edited by Herbert Sixta WILEY- VCH WILEY-VCH Verlag GmbH & Co. KGaA

2 VII Contents Preface XXIII List of Contributors XXVII List of Abbreviations XXIX Volume 1 Part I Chemical Pulping 1 1 Introduction 3 Herbert Sixta 1.1 Introduction The History of Papermaking Technology, End-uses, and the Market Situation Recovered Paper and Recycled Fibers Outlook 15 2 Raw Material for Pulp 21 Gerald Koch 2.1 Wood Chemical Composition of Wood Cellulose Hemicelluloses Lignin Extractives Inorganic Components Wood Structure and Morphology Ultrastructure and Distribution of Cell Wall Components Lignification of the Cell Walls Functional Elements of the Conducting System 46 Handbook of Pulp. Edited by Herbert Sixta (Ed.) Copyright 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim ISBN:

3 VIII I Contents The Microscopic Structure of Wood Cell Types Softwood and Hardwood Structure Reaction Wood Juvenile Wood Secondary Changes Outlook Nano-structure of Fibers Topochemical Distribution of Lignin and Phenolic Extractives 61 3 Wood Yard Operations 69 Jorg B. Ressel 3.1 Raw Material Storage Debarking Debarking Methods Drum Debarker Rotary Debarker Ring Debarkers Chipping and Screening Disc Chipper Drum Chipper The Andritz H Q - Sizer and Rechipper Chip Conditioner Chipper Canter Line: Profiling Line in Softwood Sawmills Chip screening Mechanical Screening Wind Screening Air Density Separator (ADS) Process Control and Automation Transport and Handling Systems Log Handling Stationary Conveyor Systems Chip Storage Chip Storage Systems Wood Yard Losses and Waste Reduction Specific Causes of Waste Generation Pollution Prevention Options Chemical Pulping Processes 109 Herbert Sixta, Antje Potthast, Andreas W. Krotschek 4.1 Introduction Kraft Pulping Processes General Description Kraft Cooking Liquors 113

4 Contents IX Mass Transfer in Kraft Cooking Purpose of Impregnation Heterogeneity of Wood Structure Steaming Penetration Diffusion Diffusion Model Effect of Impregnation on the Uniformity of Delignification Numerical Solution of the Diffusion Model Chemistry of Kraft Cooking 164 Antje Potthast Lignin Reactions Reactions of Carbohydrates Reactions of Extractives An Overview of Reactions During Kraft Pulping Inorganic Reactions Kraft Pulping Kinetics 185 Herbert Sixta Introduction Review of Kraft Cooking Models Structure of a Selected Kinetic Model for Kraft Pulping Process Chemistry of Kraft Cooking Standard Batch Cooking Process Modified Kraft Cooking Polysulfide and Anthraquinone Pulping Multistage Kraft Pulping Prehydrolysis Prehydrolysis: Kraft Pulping Pulping Technology and Equipment 366 Andreas W. Krotschek Batch Cooking versus Continuous Cooking Batch Cooking Technology and Equipment Continuous Cooking Technology and Equipment Sulfite Chemical Pulping 392 Herbert Sixta Introduction Cooking Chemicals and Equilibria Impregnation Chemistry of (Acid) Sulfite Cooking 405 Antje Potthast Reactions of Lignin Reactions of Carbohydrates: Acid Hydrolysis Reactions of Extractives Process Chemistry of Acid Sulfite Pulping 427 Herbert Sixta

5 X Contents Basic Technology Influence of Reaction Conditions Alternative Sulfite Pulping Concepts Magnefite Process Two-Stage Neutral Magnefite (Bisulfite-MgO) Sivola Processes Stora Processes (Hydrogen Sulfite or Monosulfite-Acid Sulfite) Alkaline Sulfite Pulping Pulp Washing 511 Andreas W. Krotscheck 5.1 Introduction Pulp Washing Theory Overview Drainage Compressive Dewatering Diffusion Sorption Principles of Washing Dilution/Extraction Washing Displacement Washing Compressive Dewatering Multi-Stage Washing Fractional Washing Washing Parameters Overview Dilution Factor Feed and Discharge Consistencies ph Entrainment of Air Temperature Equipment-Specific Parameters Washing Efficiency Overview Wash Yield Displacement Ratio Norden Efficiency Factor Standardized Norden Efficiency Factor Washing Equipment General Remarks Rotary Drum Washers Conventional Drum Washers Drum Displacer Belt Washers 551

6 Contents XI Diffusion Washers Atmospheric Diffuser Pressure Diffuser Roll Presses In-Digester Washing Pulp Screening, Cleaning, and Fractionation 561 Andreas W. Krotscheck 6.1 Introduction Screening Theory Introduction Flow Regime Fiber Passage and Reject Thickening Selective Fiber Passage Screening Parameters Equipment Parameters Screen Basket Rotor Operating Parameters Reject Rate Accept Flow Rate Feed Consistency Temperature Rotor Tip Velocity Furnish Parameters Pulp Fibers Contaminants Entrained Air Centrifugal Cleaning Theory Introduction Flow Regime Sedimentation Underflow Thickening Selective Separation Centrifugal Cleaning Parameters Cyclone Parameters Operating Parameters Flow Rate and Pressure Drop Feed Consistency Temperature Furnish Parameters Pulp Fibers Contaminants Separation Efficiency 588

7 XII Contents Screening and Cleaning Efficiency Fractionation Efficiency Removal Efficiency Fractionation Index Screening and Cleaning Applications Selective Contaminant Removal Knots Shives Bark Sand and Stones Metals and Plastics Fractionation Systems for Contaminant Removal and Fractionation Basic System Design Principles Systems for Contaminant Removal Arrangement Fiber Loss versus Efficiency Systems for Fractionation Screening and Cleaning Equipment Pressure Screens Atmospheric Screens Secondary Knot Screens Vibratory Screens Hydrocyclones 605 Volume 2 7 Pulp Bleaching 609 Herbert Sixta, Hans-Ullrich Suss, Antje Potthast, Manfred Schwanninger, and Andreas W. Krotscheck 7.1 General Principles Classification of Bleaching Chemicals Bleaching Operations and Equipment 613 Andreas W. Krotscheck Basic Rheology of Pulp-Liquor Systems Generic Bleaching Stage Set-Up Medium Consistency Pumps Medium Consistency Mixers High-Shear Mixers Static Mixers Atmospheric Steam Mixers Medium Consistency Reactors Atmospheric Upflow Reactors 623

8 Contents XIII Atmospheric Downflow Reactors Pressurized Reactors Blowtank Agitators Washing Oxygen Delignification Introduction Chemistry of Oxygen Delignification 632 Manfred Schwanninger Bleachability Lignin Structures and their Reactivity Oxygen (Dioxygen) and its Derivatives A Principal Reaction Schema for Oxygen Delignification Carbohydrate Reactions in Dioxygen-Alkali Delignification Processes Residual Lignin-Carbohydrate Complexes (RLCC) Inorganics (Metals) and their Role in the Protection/ Degradation of Cellulose Mass Transfer and Kinetics 671 Herbert Sixta Kinetics of Delignification Kinetics of Cellulose Chain Scissions Application of Surfactants A Model to Predict Industrial Oxygen Delignification Theoretical Base of the van Heiningen Model Case Study Process Variables Temperature Retention Time Alkali Charge ph Value Final ph Alkali Source Oxygen Charge, Oxygen Pressure Consistency Pulp Components and Impurities Effect of Metal Ion Concentration Residual Lignin Structures Carry-Over Xylan Content Selectivity of Oxygen Delignification Process and Equipment MC versus HC Technology Process Technology Process Equipment 731

9 XIV Contents Pulp Quality Chlorine Dioxide Bleaching A.I Introduction Physical and Chemical Properties and Definitions Behavior of Chlorine Dioxide in Aqueous Solution Inorganic Side Reactions during Chlorine Dioxide Bleaching of Wood Pulps A3 Generation of Chlorine Dioxide Chemistry of Chlorine Dioxide Treatment 745 Manfred Schwanninger Chlorination Products Performance of Chlorine Dioxide Bleaching Standard Chlorine Dioxide Bleaching Chlorine Dioxide Bleaching of Oxygen-Delignified Kraft Pulps Modified Chlorine Dioxide Bleaching Technology of Chlorine Dioxide Bleaching 770 Andreas W. Krotscheck 7A.7 Formation of Organochlorine Compounds Ozone Delignification Introduction Physical Properties of Ozone Ozone Generation Chemistry of Ozone Treatment 785 Manfred Schwanninger Ozone Decomposition Degradation of Lignin Degradation of Carbohydrates Process Conditions Mass Transfer Mixing and Mixing Time Effect of Pulp Consistency A Effect of ph Effect of Temperature Effect of Transition Metal Ions Effect of Carry-Over Effect of Pretreatments and Additives Effect of Sodium Borohydride after Treatment Effect of Alkaline Extraction Technology of Ozone Treatment 826 Andreas W. Krotscheck Medium-Consistency Ozone Treatment High-Consistency Ozone Treatment Ozone/Oxygen Gas Management Application in Chemical Pulp Bleaching Selectivity, Efficiency of Ozone Treatment of Different Pulp Types 829

10 Effect of Ozonation on the Formation of Carbonyl and Carboxyl Groups Effect of Ozonation on Strength Properties A Typical Conditions, Placement of Z in a Bleaching Stage Hydrogen Peroxide Bleaching 849 Hans-Ullrich Suss Introduction H 2 O 2 Manufacture Physical Properties Chemistry of hydrogen peroxide bleaching 853 Manfred Schwanninger Decomposition of H 2 O Residual Lignin Carbohydrates Process Parameters 860 Hans-Ullrich Suss Metals Management Alkaline Decomposition of H 2 O Thermal Stability of H 2 O 2 and Bleaching Yield Pressurized Peroxide Bleaching Technology of H 2 O 2 Bleaching 866 Andreas W. Krotscheck Atmospheric Peroxide Bleaching Pressurized Peroxide Bleaching Application in Chemical Pulp Bleaching 868 Hans-Ullrich Suss Stabilization of Brightness with H 2 O Catalyzed Peroxide Bleaching Application in TCF Sulfite Pulp Bleaching A Activators for H 2 O 2 Bleaching Peracetic Acid in Pulp Bleaching Hot Acid Hydrolysis Alternative Bleaching Methods Bleach Plant Liquor Circulation 887 Andreas W. Krotscheck Introduction Intra-Stage Circulation and Circulation between Stages Open and Closed Operation of Bleaching Stages Construction Material Compatibility Implications of Liquor Circulation 893 Contents XV

11 XVI Contents 8 Pulp Purification 933 Herbert Sixta 8.1 Introduction Reactions between Pulp Constituents and Aqueous Sodium Hydroxide Solution Cold Caustic Extraction NaOH Concentration Time and Temperature Presence of Hemicelluloses in the Lye Placement ofcce in the Bleaching Sequence Specific Yield Loss, Influence on Kappa Number Molecular Weight Distribution Hot Caustic Extraction Influence of Reaction Conditions on Pulp Quality and Pulp Yield NaOH Charge and Temperature in E, (EO), and (E/O) Treatments Xylan versus R18 Contents Purification versus Viscosity Purification versus Kappa Number and Extractives Composition of Hot Caustic Extract MgO as an Alternative Alkali Source Recovery 967 Andreas W. Krotscheck and Herbert Sixta 9.1 Characterization of Black Liquors Chemical Composition Physical Properties Viscosity Boiling Point Rise (BPR) Surface Tension Density Thermal Conductivity Heat Capacity [8,11] Chemical Recovery Processes Overview Black Liquor Evaporation Introduction Evaporators Multiple-Effect Evaporation Vapor Recompression Kraft Chemical Recovery Kraft Recovery Boiler Causticizing and Lime Reburning The Future of Kraft Chemical Recovery Sulfite Chemical Recovery 994

12 Contents XVII 10 Environmental Aspects of Pulp Production 997 Hans-Ulrich Suss 10.1 Introduction A Glimpse of the Historical Development Emissions to the Atmosphere Emissions to the Aquatic Environment Solid Waste Outlook Pulp Properties and Applications 1009 Herbert Sixta 11.1 Introduction Paper-Grade Pulp Dissolving Grade Pulp Introduction Dissolving Pulp Characterization Pulp Origin, Pulp Consumers Chemical Properties Supramolecular Structure Cell Wall Structure Fiber Morphology Pore Structure, Accessibility Degradation of Dissolving Pulps Overview of Pulp Specification 1060 II Mechanical Pulping 1069 Jurgen Blechschmidt, Sabine Heinemann, and Hans-Ulrich Suss 1 Introduction 1071 Jurgen Blechschmidt and Sabine Heinemann 2 A Short History of Mechanical Pulping 1073 Jurgen Blechschmidt and Sabine Heinemann 3 Raw Materials for Mechanical Pulp 1075 Jurgen Blechschmidt and Sabine Heinemann 3.1 Wood Quality Processing of Wood 1076

13 XVIII Contents Wood Log Storage Wood Log Debarking Wood Log Chipping Mechanical Pulping Processes 1079 Jurgen Blechschmidt and Sabine Heinemann 4.1 Grinding Processes Principle and Terminology Mechanical and Thermal Processes in Grinding Softening of the Fibers Defibration (Deliberation) of Single Fibers from the Fiber Compound Influence of Parameters on the Properties of Groundwood Grinders and Auxiliary Equipment for Mechanical Pulping by Grinding A.I Pocket Grinders Chain Grinders Pulp Stones Pressure Grinding Refiner Processes Principle and Terminology Mechanical, Thermal, and Chemical Processes in the Refiner Process Machines and Aggregates for Mechanical Pulping by Refining Processing of Mechanical Pulp and Reject Handling: Screening and Cleaning 1113 Jurgen Blechschmidt and Sabine Heinemann 5.1 Basic Principles and Parameters Machines and Aggregates for Screening and Cleaning Reject Treatment and Heat Recovery Bleaching of Mechanical Pulp 1123 Hans-Ulrich Suss 6.1 Bleaching with Dithionite Bleaching with Hydrogen Peroxide Technology of Mechanical Pulp Bleaching Latency and Properties of Mechanical Pulp 1137 Jurgen Blechschmidt and Sabine Heinemann 7.1 Latency of Mechanical Pulp Properties of Mechanical Pulp 1138

14 Contents XIX III Recovered Paper and Recycled Fibers 1147 Hans-Joachim Putz 1 Introduction Relevance of Recycled Fibers as Paper Raw Material Recovered Paper Grades Europe North America and Japan United States Japan Basic Statistics Utilization Rate Recovery Rate Recycling Rate Deinked Pulp Capacities Future Development of the Use of Recovered Paper Collection of Recovered Paper Pre-Consumer Recovered Paper Post-Consumer Recovered Paper Pick-Up Systems Drop-Off Systems Efficiency of Different Collection Systems Municipal Solid Waste Sources of Recovered Paper Sorting, Handling, and Storage of Recovered Paper Sorting Handling Storage Legislation for the Use of Recycled Fibers Europe United States of America Japan 1198 Appendix: European List of Standard Grades of Recovered Paper and Board (February, 1999) 1203

15 XX I Contents IV Analytical Characterization of Pulps 1211 Erich Cruber 1 Fundamentals of Quality Control Procedures The Role of QC Basics of QC-statistics Sampling Conditions for Testing and/or Conditioning Disintegration Determination of Low Molecular-Weight Components Moisture Inorganic Components Ashes Total Ash SulfatedAsh Acid-Insoluble Ash Determination of Single Elements Survey of Chemical Procedures Atomic Absorption Spectroscopy (AAS) X-ray Fluorescence Spectroscopy (XFS) Electron Spectroscopy for Chemical Application (ESCA) Extractives Water Extractives Test Water Cold Water Extraction Hot Water Extraction Analysis of Water Extracts Chlorine Compounds Macromolecular Composition Lignin Content Extent of Delignification Roe Number Chlorine Number Kappa Number (Permanganate Number) Alkali Resistance and Solubility Alkali-Soluble Components a-, P-, and y-cellulose Ri 8 and Si 8 values Composition of Polysaccharides Determination of Monosaccharides after Hydrolysis Gas Chromatography Thin-Layer Chromatography 1232

16 Liquid Chromatography Determination of Pentosans after Hydrolysis Determination of Uronic Acids after Hydrolysis Functional Groups Carbonyl Functions Copper Number Sodium Borohydride Method Hydrazine Method Oxime Method Girard-P Method Cyanohydrin Method Fluorescent Dying Carboxyl Functions Degree of Polymerization (Molecular Mass) Solvents for Cellulose CUOXAM CUEN Irori'Sodium Tartrate (EWNN) Diverse Average Values of Molecular Mass and Index of Nonuniformity Methods to Determine Molar Mass ("Molecular Weight") 1243 Contents I XXI Osmosis Scattering Methods Viscosity Measurements Solution Viscosity as a Measure of Macromolecular Chain Length Viscosity Measurements on Cellulose Pulps Molecular Weight Distribution Fractional Precipitation or Solution Size-Exclusion (Gel-Permeation) Chromatography Characterization of Supermolecular Structures Crystallinity Degree of Crystallinity X-Ray Diffraction Solid-phase NMR-Spectroscopy Reaction Kinetics Density Measurements Dimension of Crystallites Orientation of Crystallites Accessibility, Voids, and Pores Porosity Accessible Surface Water and Solvent Retention 1268

17 XXII Contents Total Water Uptake Free and Bound Water Fiber Properties Identification of Fibers Morphological Characterization Visible and UV Microscopy Electron Microscopy Fiber Dimensions Fiber Length and Width Microscopic Methods and Image Analysis Fiber Fractionation by Screening Coarseness Mechanical Properties Single Fiber Properties Wet Fiber Properties Mechanical Properties of Dry Fibers Sheet Properties Preparation of Laboratory Sheets for Physical Testing Determination of Mechanical Pulp Sheet Properties Optical Properties of Laboratory Sheets Papermaking Properties of Pulps Beating Drainage Resistance Drainage (Dewatering) Time Aging Accelerated Aging 1284 Index 1291