- •Recovered Paper and Recycled Fibers
- •Isbn: 3-527-30999-3
- •Introduction
- •Isbn: 3-527-30999-3
- •Isbn: 3-527-30999-3
- •2006, Isbn 3-527-30997-7
- •Volume 1
- •Isbn: 3-527-30999-3
- •4.1 Introduction 109
- •4.2.5.1 Introduction 185
- •4.3.1 Introduction 392
- •5.1 Introduction 511
- •6.1 Introduction 561
- •6.2.1 Introduction 563
- •6.4.1 Introduction 579
- •Volume 2
- •7.3.1 Introduction 628
- •7.4.1 Introduction 734
- •7.5.1 Introduction 777
- •7.6.1 Introduction 849
- •7.10.1 Introduction 887
- •8.1 Introduction 933
- •1 Introduction 1071
- •5 Processing of Mechanical Pulp and Reject Handling: Screening and
- •1 Introduction 1149
- •Isbn: 3-527-30999-3
- •Isbn: 3-527-30999-3
- •Isbn: 3-527-30999-3
- •Isbn: 3-527-30999-3
- •Introduction
- •Introduction
- •Isbn: 3-527-30999-3
- •1 Introduction
- •1 Introduction
- •1 Introduction
- •1 Introduction
- •1 Introduction
- •1 Introduction
- •150.000 Annual Fiber Flow[kt]
- •1 Introduction
- •1 Introduction
- •Introduction
- •Isbn: 3-527-30999-3
- •Void volume
- •Void volume fraction
- •Xylan and Fiber Morphology
- •Initial bulk residual
- •4.2.5.1 Introduction
- •In (Ai) Model concept Reference
- •Initial value
- •Validation and Application of the Kinetic Model
- •Inititial
- •Viscosity
- •Influence on Bleachability
- •Impregnation
- •Impregnation
- •Impregnation
- •Impregnation
- •Impregnation
- •Impregnation
- •Impregnation
- •Impregnation
- •Impregnation
- •Impregnation
- •Introduction
- •International
- •Impregnation
- •Influence of Substituents on the Rate of Hydrolysis
- •140 116 Total so2
- •Xylonic
- •Viscosity Brightness
- •Xyl Man Glu Ara Furf hoAc XyLa
- •Initial NaOh charge [% of total charge]:
- •Introduction
- •Isbn: 3-527-30999-3
- •Introduction
- •Isbn: 3-527-30999-3
- •Introduction
- •Introduction
- •Isbn: 3-527-30999-3
- •In 1950, about 50% of the global paper production was produced. This proportion
- •4.0% Worldwide; 4.2% for the cepi countries; and 4.8% for Germany.
- •1150 1 Introduction
- •1 Introduction
- •1 Introduction
- •Virgin fibers
- •74.4 % Mixed grades
- •Indonesia
- •Virgin fibers
- •Inhomogeneous sample Homogeneous sample
- •Variance of sampling Variance of measurement
- •1.Quartile
- •3.Quartile
- •Insoluble
- •Insoluble
- •Insoluble
- •Integral
- •In Newtonion liquid
- •Velocity
- •Increasing dp
- •2Α filter
- •0 Reaction time
- •Increasing interaction of probe and cellulose
- •Increasing hydrodynamic size
- •Vessel cell of beech
- •Initial elastic range
- •Internal flow
- •Intact structure
- •Viscosity 457
- •Isbn: 3-527-30999-3
- •1292 Index
- •Visbatch® pulp 354
- •Index 1293
- •1294 Index
- •Impregnation 153
- •Viscosity–extinction 433
- •Index 1295
- •1296 Index
- •Index 1297
- •Inhibitor 789
- •1298 Index
- •Index 1299
- •Impregnation liquor 290–293
- •1300 Index
- •Industries
- •Index 1301
- •1302 Index
- •Index 1303
- •Xylose 463
- •1304 Index
- •Index 1305
- •1306 Index
- •Index 1307
- •1308 Index
- •In conventional kraft cooking 232
- •Visbatch® pulp 358
- •Index 1309
- •In prehydrolysis-kraft process 351
- •Visbatch® cook 349–350
- •1310 Index
- •Index 1311
- •1312 Index
- •Viscosity 456
- •Index 1313
- •Viscosity 459
- •Interactions 327
- •1314 Index
- •Index 1315
- •Viscosity 459
- •1316 Index
- •Index 1317
- •Xylose 461
- •Index 1319
- •Visbatch® pulp 355
- •Impregnation 151–158
- •1320 Index
- •Index 1321
- •1322 Index
- •Xylan water prehydrolysis 333
- •Index 1323
- •1324 Index
- •Viscosity 459
- •Index 1325
- •Xylose 940
- •1326 Index
- •Index 1327
- •In selected kinetics model 228–229
- •4OMeGlcA 940
- •1328 Index
- •Index 1329
- •Intermediate molecule 164–165
- •1330 Index
- •Viscosity 456
- •Index 1331
- •1332 Index
- •Impregnation liquor 290–293
- •Index 1333
- •1334 Index
- •Index 1335
- •1336 Index
- •Impregnation 153
- •Index 1337
- •1338 Index
- •Viscose process 7
- •Index 1339
- •Volumetric reject ratio 590
- •1340 Index
- •Index 1341
- •1342 Index
- •Index 1343
- •1344 Index
- •Index 1345
- •Initiator 788
- •Xylose 463
- •1346 Index
- •Index 1347
- •Vessel 385
- •Index 1349
- •1350 Index
- •Xylan 834
- •1352 Index
6.1 Introduction 561
6.2 Screening Theory 563
6.2.1 Introduction 563
6.2.2 Flow Regime 564
6.2.3 Fiber Passage and Reject Thickening 566
6.2.4 Selective Fiber Passage 570
6.3 Screening Parameters 572
6.3.1 Equipment Parameters 572
6.3.1.1 Screen Basket 572
6.3.1.2 Rotor 573
6.3.2 Operating Parameters 575
6.3.2.1 Reject Rate 575
6.3.2.2 Accept Flow Rate 575
6.3.2.3 Feed Consistency 577
6.3.2.4 Temperature 577
6.3.2.5 Rotor Tip Velocity 577
6.3.3 Furnish Parameters 578
6.3.3.1 Pulp Fibers 578
6.3.3.2 Contaminants 579
6.3.3.3 Entrained Air 579
6.4 Centrifugal Cleaning Theory 579
6.4.1 Introduction 579
6.4.2 Flow Regime 580
6.4.3 Sedimentation 581
6.4.4 Underflow Thickening 584
6.4.5 Selective Separation 585
6.5 Centrifugal Cleaning Parameters 586
6.5.1 Cyclone Parameters 586
6.5.2 Operating Parameters 587
6.5.2.1 Flow Rate and Pressure Drop 587
6.5.2.2 Feed Consistency 587
6.5.2.3 Temperature 587
6.5.3 Furnish Parameters 587
6.5.3.1 Pulp Fibers 587
6.5.3.2 Contaminants 588
6.6 Separation Efficiency 588
Contents XI
6.6.1 Screening and Cleaning Efficiency 588
6.6.2 Fractionation Efficiency 590
6.6.2.1 Removal Efficiency 590
6.6.2.2 Fractionation Index 591
6.7 Screening and Cleaning Applications 592
6.7.1 Selective Contaminant Removal 592
6.7.1.1 Knots 593
6.7.1.2 Shives 593
6.7.1.3 Bark 593
6.7.1.4 Sand and Stones 593
6.7.1.5 Metals and Plastics 594
6.7.2 Fractionation 594
6.8 Systems for Contaminant Removal and Fractionation 594
6.8.1 Basic System Design Principles 594
6.8.2 Systems for Contaminant Removal 596
6.8.2.1 Arrangement 596
6.8.2.2 Fiber Loss versus Efficiency 598
6.8.3 Systems for Fractionation 599
6.9 Screening and Cleaning Equipment 601
6.9.1 Pressure Screens 601
6.9.2 Atmospheric Screens 604
6.9.2.1 Secondary Knot Screens 604
6.9.2.2 Vibratory Screens 605
6.9.3 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 609
7.2 Classification of Bleaching Chemicals 610
7.2 Bleaching Operations and Equipment 613
Andreas W. Krotscheck
7.2.1 Basic Rheology of Pulp-Liquor Systems 614
7.2.2 Generic Bleaching Stage Set-Up 616
7.2.3 Medium Consistency Pumps 617
7.2.4 Medium Consistency Mixers 619
7.2.4.1 High-Shear Mixers 620
7.2.4.2 Static Mixers 621
7.2.4.3 Atmospheric Steam Mixers 622
7.2.5 Medium Consistency Reactors 623
7.2.5.1 Atmospheric Upflow Reactors 623
XII Contents
7.2.5.2 Atmospheric Downflow Reactors 624
7.2.5.3 Pressurized Reactors 625
7.2.6 Blowtank 627
7.2.7 Agitators 627
7.2.8 Washing 628
7.3 Oxygen Delignification 628
7.3.1 Introduction 628
7.3.2 Chemistry of Oxygen Delignification 632
Manfred Schwanninger
7.3.2.1 Bleachability 634
7.3.2.2 Lignin Structures and their Reactivity 634
7.3.2.3 Oxygen (Dioxygen) and its Derivatives 641
7.3.2.4 A Principal Reaction Schema for Oxygen Delignification 649
7.3.2.5 Carbohydrate Reactions in Dioxygen-Alkali Delignification
Processes 657
7.3.2.6 Residual Lignin–Carbohydrate Complexes (RLCC) 666
7.3.2.7 Inorganics (Metals) and their Role in the Protection/
Degradation of Cellulose 668
7.3.3 Mass Transfer and Kinetics 671
Herbert Sixta
7.3.3.1 Kinetics of Delignification 672
7.3.3.2 Kinetics of Cellulose Chain Scissions 685
7.3.3.3 Application of Surfactants 687
7.3.4 A Model to Predict Industrial Oxygen Delignification 688
7.3.4.1 Theoretical Base of the van Heiningen Model 690
7.3.4.2 Case Study 695
7.3.5 Process Variables 701
7.3.5.1 Temperature 701
7.3.5.2 Retention Time 702
7.3.5.3 Alkali Charge 703
7.3.5.4 pH Value 704
7.3.5.5 Final pH 705
7.3.5.6 Alkali Source 706
7.3.5.7 Oxygen Charge, Oxygen Pressure 707
7.3.5.8 Consistency 708
7.3.6 Pulp Components and Impurities 708
7.3.6.1 Effect of Metal Ion Concentration 708
7.3.6.2 Residual Lignin Structures 713
7.3.6.3 Carry-Over 716
7.3.6.4 Xylan Content 719
7.3.6.5 Selectivity of Oxygen Delignification 720
7.3.7 Process and Equipment 721
7.3.7.1 MC versus HC Technology 721
7.3.7.2 Process Technology 722
7.3.7.3 Process Equipment 731
Contents XIII
7.3.8 Pulp Quality 733
7.4 Chlorine Dioxide Bleaching 734