Item Number: 0202FIN07 ISBN: 952-5216-07-1 649 pages Chapter 1 - General aspects and basic statistics 1 General aspects...12 2 Basic statistics...14 2.1 Utilization rate of recovered paper...16 2.2 Recovery rate of used paper and paper products...19 2.3 Deinked pulp (DIP) capacities...20 2.4 Future development of recovered paper utilization...21 References...23 Chapter 2 - Legislation for use of recycled fibers 1 Europe...26 1.1 Germany...29 1.2 Other European countries...35 1.2.1 Austria...35 1.2.2 Belgium...35 1.2.3 Finland...36 1.2.4 France...36 1.2.5 Sweden...37 1.2.6 The Netherlands...37 1.2.7 United Kingdom...37 2 United States...38 3 Japan...42 References...45 Chapter 3 - Collection systems, sources, and sorting of recovered paper 1 Collection systems and equipment...47 1.1 Pre-consumer recovered paper...47 1.2 Post-consumer recovered paper...48 1.2.1 Pick-up systems...48 1.2.2 Drop-off systems...49 1.3 Efficiency of different collection systems...50 1.4 Municipal solid waste...51 2 Sources of recovered paper...51 2.1 Germany...51 2.2 Western Europe...52 3 Sorting, handling, and storage of recovered paper...53 3.1 Sorting...53 3.2 Handling...55 3.2.1 Loose recovered paper...55 3.2.2 Baled recovered paper...56 3.2.3 Shredding of files...56 3.3 Storage...57 References...59 Page 1 of 10
Chapter 4 - Recovered paper grades, quality control, and recyclability 1 Recovered paper grades...61 1.1 Europe...61 1.2 United States and Japan...65 1.2.1 United States...65 1.2.2 Japan...66 1.3 Recovered paper grades in different countries...67 2 Quality control of recovered paper...67 2.1 Equipment for sampling...67 2.1.1 Sampling of baled recovered paper...67 2.1.2 Sampling of loose recovered paper...69 2.2 Quality characteristics...70 2.2.1 Moisture content...70 2.2.2 Composition and other characteristics...71 3 Recyclability of paper products...79 3.1 Determination of nonpaper components...80 3.2 PTS test method on recyclability...80 3.3 FINAT test method on recyclability...83 3.4 INGEDE test method on recyclability...83 3.5 Effect on process water...85 References...86 Chapter 5 - Unit operations and equipment in recycled fiber processing 1 General overview...91 2 Slushing and pulping...95 2.1 Objectives and system integration...95 2.2 Principles...96 2.3 Machinery and effects...97 2.3.1 Pulpers...97 2.3.2 Drum pulpers...104 3 Deflaking...106 3.1 Objectives and system integration...106 3.2 Principles...106 3.3 Machinery...107 3.3.1 Deflakers...107 3.3.2 Disk screens for deflaking...108 4 Screening and fractionation...109 4.1 Objectives and system integration...109 4.2 Principles...110 4.2.1 Separation probability...110 4.2.2 Influence of inflow conditions on cleanliness efficiency...111 4.2.3 Particle deformability and shear forces in the screen...112 4.2.4 Flow through screen openings...113 4.2.5 Uniform flow through cylindrical screens...114 4.2.6 Assessment of separation processes...115 4.2.7 Difference between screening and fractionation...118 4.3 Machinery and design versions...119 4.3.1 Coarse screening...120 4.3.2 Fine screening...124 4.3.3 Fractionation...127 Page 2 of 10
4.4 Screening results...127 4.4.1 Individual machines...127 4.4.2 Screening systems...130 4.4.3 Thickening...133 4.4.4 Deflaking...133 5 Centrifugal cleaning...134 5.1 Objectives and system integration...134 5.2 Principles...136 5.2.1 Hydrodynamic flow principles...136 5.2.2 Hydrocyclone theory...137 5.2.3 Assessment of cleaning results...140 5.2.4 Separation efficiency and cleaner operation...140 5.3 Machinery and cleaning effect...141 5.3.1 HC cleaners...143 5.3.2 MC cleaners...145 5.3.3 LC cleaners...145 5.3.4 Cleaner systems...148 5.3.5 Final stage cleaners...149 5.3.6 Centrifugal cleaners with rotating housing...150 5.3.7 Abrasion...150 6 Flotation...151 6.1 Objectives and system integration...151 6.2 Principles...153 6.2.1 Prerequisites for good flotation results...153 6.2.2 Flotation process...153 6.3 Flotation cells and their operating principles...158 6.3.1 Characteristics of different flotation cells...158 6.3.2 Flotation cells on the market...158 6.3.3 Foam deaeration...165 6.4 Assessment of flotation results...165 6.4.1 Main quality criteria of deinked pulp...166 6.4.2 Laboratory cells...167 7 Dewatering...168 7.1 Objectives and system integration...168 7.2 Principles...169 7.3 Machinery and effects...172 7.3.1 Belt and drum filters...172 7.3.2 Disk filters...173 7.3.3 Screw press...175 7.3.4 Other kinds of dewatering machinery...176 8 Washing...176 8.1 Objectives and system integration...176 8.2 Principles...177 8.3 Machinery...181 8.3.1 Belt filter type machines...181 8.3.2 Disk thickeners...184 8.3.3 Spray filters...184 8.3.4 Pressure screen type washers...185 9 Dispersion and kneading...185 9.1 Objectives and system integration...185 9.2 Principles...186 9.2.1 Particle shear strength...186 Page 3 of 10
9.2.2 Dispersion mechanisms...187 9.3 Machinery design...188 9.3.1 Dispersion subsystem...188 9.4 Dispersion results...191 9.5 Applications of disk and kneading dispergers...191 10 Refining...193 10.1 Objectives and system integration...193 10.2 Principles...195 10.2.1 LC refining...195 10.2.2 HC refining...196 10.3 Machinery and design versions...196 10.3.1 LC refining...196 10.3.2 HC refining...198 10.4 Refining results...199 10.4.1 Refining of recycled fiber pulp for packaging papers...199 10.4.2 Refining of recycled fiber pulp for writing and printing papers...200 11 Mixing and storing...201 11.1 Objectives...201 11.2 Principles...202 11.2.1 Mixing...202 11.2.2 Storing and prevention of demixing...202 11.3 Machine technology...202 11.3.1 Mixing...202 11.3.2 Storing and prevention of demixing...203 11.3.3 Prevention of winding of components...203 11.3.4 Storing suspensions with high stock consistency...204 12 Acknowledgement...204 References...205 Chapter 6 - Design of recycled fiber processes for different paper and board grades 1 Introduction...211 2 White paper grades...212 2.1 Standard newsprint and improved paper grades...212 2.1.1 Production level...213 2.1.2 Total plant concept...220 2.1.3 Rejects and sludge treatment...220 2.1.4 Water management...222 2.1.5 Process water clarification...224 2.2 High-quality writing and printing paper grades...226 2.3 Market pulp...226 2.4 Tissue...228 3 Packaging paper and board grades...230 3.1 Test liner...230 3.2 Fractionation systems...235 3.3 Boxboard...237 References...239 Chapter 7 - Deinking chemistry 1 Introduction...241 2 Pulping...242 Page 4 of 10
3 Ink redeposition on fibers...244 4 Flotation...244 5 Fatty acid collectors...246 5.1 Fats and fatty acids...246 5.2 Soap...247 5.3 Handling fatty acid and soap...249 5.4 Dosing point and dosage...251 5.5 Mechanism of function...252 5.6 Fatty acid composition...253 5.7 Soap collectors...253 5.8 Biodegradability...254 6 Synthetic collectors...254 7 Semi-synthetic collectors (emulsions)...256 7.1 Combination of soap and emulsion...257 8 Choice of collector...257 9 Carryover of fatty acids and wood resins...258 9.1 Case study...259 10 Influence of ph...260 11 Enzymes in the treatment of recycled fibers...261 12 Deinking by washing...262 13 Treatment of process water...263 References...264 Chapter 8 - Deinkability of printing inks 1 Definition of deinkability...267 2 Composition of inks...269 2.1 Inks for conventional printing processes...269 2.1.1 Carriers and binders...270 2.1.2 Colorants (pigments and dyes)...274 2.1.3 Additives...276 2.2 Inks for nonimpact printing processes...277 2.2.1 Toner printing...278 2.2.2 Ink-jet printing...280 2.2.3 Thermographic printing...281 2.2.4 Electrosensitive processes...282 3 Deinkability of printed products...282 3.1 Newspapers...282 3.1.1 Vegetable oil vs. mineral oil inks...283 3.1.2 Water-based flexographic inks for newsprint...284 3.2 Magazines...288 3.2.1 Coated and uncoated magazine paper...288 3.2.2 Toluene- vs. water-based rotogravure inks...290 3.3 Nonimpact inks...291 3.4 Effect of aging...293 4 Evaluation of deinking results...294 4.1 Yield of deinking processes...294 4.2 Optical parameters of deinked pulp...295 4.3 Particle analysis by image analysis...298 References...302 Chapter 9 - Bleaching of deinked pulps Page 5 of 10
1 Importance of DIP bleaching...307 1.1 Wood-containing DIP...308 1.2 Wood-free DIP...308 1.3 Special aspects of DIP bleaching...309 1.3.1 Chemical fibers...310 1.3.2 Mechanical fibers...311 1.3.3 Impurities...311 1.4 Conclusion...311 2 Lignin-preserving bleaching...313 2.1 Peroxide bleaching (P)...314 2.1.1 Chemistry...314 2.1.2 Peroxide stabilization...316 2.1.3 Process parameters...321 2.1.4 Point of application...322 2.1.5 Experiences from technical applications...324 2.2 Dithionite bleaching (Y)...326 2.2.1 Chemistry...327 2.2.2 Process parameters...332 2.3 FAS bleaching (FAS)...331 2.3.1 Chemistry...331 2.3.2 Process parameters...332 2.4 Combined bleaching stages...335 2.4.1 Two-stage bleaching...335 2.4.2 Multistage bleaching...339 3 Lignin-degrading bleaching...339 3.1 Bleaching with chlorine-containing chemicals...340 3.1.1 Hypochlorite bleaching (H)...341 3.1.2 Chlorine-Containing bleaching sequences...341 3.1.3 Chlorine dioxide bleaching (D)...342 3.2 Bleaching with oxygen chemicals...343 3.2.1 Oxygen bleaching (O)...344 3.2.2 Ozone bleaching (Z)...348 3.2.3 Alternative bleaching process...351 References...353 Chapter 10 - Papermaking potential of recycled fiber 1 Differences between virgin and recycled fibers...359 1.1 Introduction...359 1.2 Effects of recycling on chemistry and morphology of fibers...359 1.2.1 Hornification of fibers during drying and recycling...359 1.2.2 Changes in fiber morphology and flexibility...364 1.2.3 Effects of chemical conditions on fiber flexibility...367 1.2.4 Changes in surface chemistry of fibers...368 1.3 Effects of recycling on pulp sheet properties...371 1.3.1 Effects on strength properties in recycling...371 1.3.2 Effect on other properties...374 1.4 Validity of experimental simulations of actual paper recycling...375 1.4.1 Design of recycling experiments...375 1.4.2 Chemical conditions in recycling experiments...376 2 RCF quality related to remaining contaminants and inks...377 Page 6 of 10
2.1 Classification of contaminants...378 2.2 Removal techniques for contaminants...381 2.3 Effects on RCF quality...382 2.3.1 Effects of residual ink particles...382 2.3.2 Effects of colored fibers...384 2.3.3 Effects of stickies...384 2.3.4 Effects of other detrimental substances...385 3 Modeling of age distribution of RCF...387 3.1 One-parameter model...389 3.2 Two parameter model...393 3.3 Multiparameter model... 4 Recycled fiber in papermaking...398 4.1 General aspects...398 4.2 Downgrading and upgrading of of recovered paper...399 4.2.1 Downgrading...399 4.2.2 Upgrading...399 4.3 Effects of deinking process yield on pulp characteristics...400 4.3.1 Losses of fines and mineral pigments in deinking process...401 4.3.2 Fiber yield in deinking flotation...402 4.3.3 Effect of flotation on strength properties...402 4.4 Improving papermaking potential of RCF by mechanical treatment...403 4.4.1 Effects of refining on mechanical fibers...403 4.5 Effects of refining on deinked pulp...404 4.6 Effect of refining on hornified chemical fibers...405 4.6.1 Effect of chemical conditions on refining results...407 4.6.2 Effect of elevated temperature on RCF during dispersing or refining...408 4.6.3 Effect of high-consistency treatment on curl of RCF...409 4.7 Effects of recycled pulp on wet end chemistry of paper machine...410 4.7.1 Carryover of deinking chemicals...410 4.7.2 Return of used wet end chemicals back to papermaking...412 4.8 Reduction of water consumption in RCF process...413 4.8.1 Characteristics of anionic trash derived from recycled pulps...414 4.8.2 Chemical oxygen demand (COD) derived from recycled pulps...416 4.8.3 Effects of dissolved inorganics in recycled pulps...417 4.8.4 Removal of dissolved and colloidal material from recycled fiber circuits...419 4.9 Characteristics of deinked pulp fibers for runnability...421 4.9.1 Effect of DIP on dewatering in manufacture in printing grades...421 4.9.2 Performance of recycled chemical pulp as reinforcement fibers...422 4.10 Effects of growing RCF use on quality of printing paper grades...423 4.10.1 Effects of increasing recycling rate on quality of printing paper grades...423 4.10.2 Deinked pulp in magazine paper grades...426 4.11 Quality potential of RCF derived from office paper...427 4.12 Challenges for manufacturing of packaging grades from RCF furnish...428 4.12.1 Trends today and tomorrow...428 4.12.2 Optimization of refining for OCC pulps...429 4.12.3 Challenges for strength properties of packaging grades...430 References...433 Chapter 11 - Stickies in recycled fiber pulp 1 What are stickies?...441 1.1 Classification of stickies...442 Page 7 of 10
1.1.1 Size of stickies...443 1.1.2 Type of stickies...443 1.1.3 Behavior of stickies...444 1.2 Problems caused by stickies...445 1.3 Cost of impact stickies...445 2 Origins of stickies...447 2.1 Adhesives...447 2.1.1 Hot melt adhesives...449 2.1.2 Dispersion adhesives...449 2.1.3 Solvent adhesives...450 2.1.4 Pressure sensitive adhesives...451 2.2 Printing inks...452 2.3 Coating binders...453 2.4 Wood derivatives...453 2.5 Papermaking adhesives...453 2.6 Chemical substances in potential stickies...454 3 Adsorption of stickies...455 4 Characterization of stickies...458 4.1 Deposit analyses...459 4.2 Handsheet inspection methods...463 4.3 Screening methods...464 4.4 Adsorption methods...468 4.5 Extraction methods...469 4.6 Precipitation methods...470 4.7 Other methods...472 4.8 Conclusions...473 5 Control of stickies...473 5.1 Alteration methods...474 5.2 Avoidance methods...477 5.3 Removal methods...478 5.3.1 Screening...479 5.3.2 Cleaning...483 5.3.3 Flotation...485 5.3.4 Washing...489 5.3.5 Other techniques...490 5.4 Dispersion methods...491 5.5 Passivation methods...492 5.5.1 Minerals...492 5.5.2 Synthetic fibers...494 5.5.3 Zirconium chemicals...495 5.5.4 Other chemicals...495 5.6 Prevention methods...497 5.6.1 Coating of wires, felts, and rolls...497 5.6.2 Machine clothing cleaning...498 References...499 Chapter 12 - Final fate of waste from recovered paper processing and non-recycled paper products 1 Categories of paper mill waste...507 2 Use and final disposal of solid waste from recovered paper processing...509 2.1 Solid waste composition and characteristics...510 Page 8 of 10
2.1.1 Rejects...511 2.1.2 Deinking sludges...512 2.2 In-mill pre-handling...516 2.2.1 Dewatering...516 2.2.2 Drying...517 2.3 Energy recovery in internal and external combustion facilities...519 2.3.1 Grate combustion...521 2.3.2 Fluidized bed combustion...522 2.3.3 Multiple hearth combustion...524 2.3.4 Which combustion technology for which type of waste?...525 2.3.5 Emissions...525 2.3.6 Ash composition and ash use...529 2.3.7 Co-firing of sludges and rejects...530 2.4 Composting and agricultural use...531 2.4.1 Composting conditions...531 2.4.2 Compsting processes...533 2.4.3 Compost applications...535 2.4.4 Composting of rejects and sludges...536 2.4.5 Agricultural use...537 2.5 Use in other industries...538 2.5.1 Cement production...538 2.5.2 Brick production...541 2.6 Landfilling...542 2.6.1 Types of landfills...543 2.6.2 Landfill gas generation...544 2.6.3 Leakage generation...545 2.6.4 Landfill sealing systems...545 2.6.5 Landfilling of waste from recovered paper processing mills...546 2.7 New developments...547 2.7.1 Wet oxidation processes...547 2.7.2 Filler recovery from combustion ashes...551 2.7.3 Fermentation processes...552 2.7.4 Hydrolysis processes...552 2.7.5 Pyrolysis processes...553 2.7.6 Production of cat litter and absirber materials...553 3 Use and final disposal of nonrecycled paper products...554 3.1 Landfilling of nonrecycled paper as a component of MSW...557 3.2 Composting of nonrecycled paper as a component of biowaste fro households...558 3.3 Incineration of nonrecovered paper s a component of MSW...559 3.4 Incineration of nonrecycled paper...561 3.4.1 Nonrecycled paper as a biofuel...563 3.4.2 Pre-treatment of recovered paper as a biofuel...563 3.4.3 Emissions...564 4 Wastewater from recovered paper processing and wastewater treatment...567 4.1 Characterization of untreated wastewater...567 4.2 Wastewater treatment...570 4.2.1 Suspended solids removal...570 4.2.2 Biological treatment...572 4.3 Characterization of treated wastewater...580 4.4 Closed water circuits...581 References...588 Page 9 of 10
Chapter 13 - Environmental aspects 1 Paper recycling and ecological labeling...593 1.1 The German Blue Angel...594 1.2 The Nordic Swan...595 1.3 EU ecological labeling...597 2 Paper recycling and CO 2 balance...600 2.1 Causes and consequences of the greenhouse effect...606 2.2 Future strategies for counteracting with the greenhouse effect...602 2.3 CO 2 balance of the pulp and paper industry...606 3 Heavy metal content of recovered paper...611 3.1 Origin of heavy metals...611 3.2 Sinks of heavy metals in processing of recovered paper...616 4 Content of chloro-organics in recovered paper...619 4.1 Origin of chloro-organic compounds...619 4.1.1 AOX compounds...619 4.1.2 Dioxins and furans...621 4.1.3 Pentachlorophenol...622 4.1.4 Polychlorinated biphenyls...624 4.2 Sinks of chloro-organic compounds in processing recovered paper...625 4.2.1 OX balance...625 4.2.2 Dioxin and furan balance...626 References...627 Page 10 of 10