WOOD 120 Pulp and Paper

Raw material Paper products

Chemical pulp mill http://w3.upm-kymmene.com/upm/internet/cms/upmmma.nsf/lupGraphics/Botnia_Fray%20Bentos%20mill_1.jpg/$file/Botnia_Fray%20Bentos%20mill_1.jpg

Chemical pulp mill http://www.metsopaper.com/paper/MPwGeneral.nsf/WebWID/WTB-061228-2256F-E7612/$File/Total_scope_with_large_text.jpg

Composition of Paper Surface Section through paper sheet

Lignin “glues” wood cells together

fibers or fiber bundles wood

Pulping Mechanical Uses heat and mechanical energy Higher yield Lower quality Chemical Uses heat and chemical energy Lower yield Higher quality

World Pulp Production (2012) (x106 metric tonnes) Recovered paper 212.8 Mechanical pulp 28.9 Full chemical pulp 98.1 Kraft 94.7 Sulphite 3.4 Dissolving pulp 4.9 Non-wood fiber pulp 16.1

Raw material – wood supply Logs Chips http://www.partonlumber.com/images/000_0334.jpg www.panoramio.com/photos/original/3042908.jpg http://www.unitedeagle.cn/upimages/20083311435587662.jpg

Pulp and Paper – overview of production stages http://www.energysolutionscenter.org/gasirpaper/Images/PaperManfLine.jpg

Pulping http://www.energysolutionscenter.org/gasirpaper/Images/PaperManfLine.jpg

Pulp treatment http://www.energysolutionscenter.org/gasirpaper/Images/PaperManfLine.jpg

Papermaking http://www.energysolutionscenter.org/gasirpaper/Images/PaperManfLine.jpg

Mechanical pulping fibers or fiber bundles wood

Stone ground wood Refiner pulps Mechanical Pulping Stone ground wood Refiner pulps

Debarking Drum debarkers

Stone Ground Wood bolts of wood hydraulic pistons grinding stone pulp slurry http://chempatec-auhorn.com/images/pressurizedmechanicalpulpproduction001_480.jpg

Stone Ground Wood

Stone Ground Wood Raw material – short logs (bolts) High yield Low quality fibers or fiber bundles High energy input Pulp suitable for tissues

Refiner pulping

Pretreatment of chips

Refiner pulping http://www.globalequip.com/photos/bg_901371.001_2.jpg http://www.triple-r.co.nz/pop/pop_pulp09.html

Multiple refiners in parallel http://www.metsopaper.com/paper/MPwFiber.nsf/WebWID/WTB-041123-2256F-3E65B/$File/TMP_blue222.jpg

Refiner pulping Raw material – chips Lower yield than SGW Medium quality fibers or fiber bundles High energy input Pulp suitable for newsprint

The “Alphabet Pulps” RMP refiner mechanical pulp TMP thermo mechanical pulp CTMP chemi thermo mechancial pulp SGW stone ground wood PGW pressurized ground wood NSSC neutral sulfite semi chemical

Chemical pulping wood individual fibers

Sulfate process (Kraft) Sulfite process Chemical Pulping Sulfate process (Kraft) Sulfite process

Kraft process Delignifies wood by fragmenting lignin into smaller units adding chemical groups to increase the lignin’s solubility Tolerates wide range of species High strength pulp Lower yield than mechanical pulps

Kraft digester - continuous http://us.magnetrol.com/Images/Applications/PulpDigester.jpg http://www.outokumpu.com/35127.epibrw 

Kraft pulping – continuous digester Chips and pulping chemicals Steam Blow valve Gases Pulp

Kraft liquor recovery cycle Wood Pulping Pulp White liquor Washing Bleaching Evaporation Cauticising Bailing & Shipping Black liquor Green liquor Burning Green liquor recovery cycle

Bleaching / Brightening Beating (refining) Pulp treatment Bleaching / Brightening Beating (refining)

Pulp and Paper – overview of production stages http://www.energysolutionscenter.org/gasirpaper/Images/PaperManfLine.jpg

http://www.chmltech.com/pulppaper_files/pulp%20bleaching.jpg

Raw material Paper products

Bleaching vs. Brightening Continuation of pulping process Removal of residual lignin left after pulping More permanent Applied to chemical pulps Brightening Distinct from pulping process Impact chromophoric structures in lignin More temporary Applied to mechanical pulps

Bleaching/brightening chemicals C chlorine Cl2 D chlorine dioxide ClO2 O oxygen O2 Z ozone O3 P peroxide H2O2 E alkaline extraction NaOH

Bleaching/brightening sequences Classic e.g., C E D E D Elemental Chlorine Free (ECF) e.g., D E D E D Totally Chlorine Free (TCF) e.g., O Z E P

Bleaching Towers http://www.andritz.com/cir-pic-pk-ar-2002.jpg

Pulp Beating Flattens fibers to produce larger surface area – increases hydrogen bonding between fibers Unravels fibers to some degree Optimum beating time to achieve best paper properties

Pulp Beating Jordan refiner

Pulp Beating After beating Before beating Internal and external defibrillation take place

Papermaking Foudrinier machine - thinner paper sheet - faster production speed Cylinder machine - thicker paper sheet - slower production speed

Papermaking Foudrinier machine - thinner paper sheet - faster production speed

Foudrinier papermaking machine http://www.risiinfo.com/images/magazine/pp_mag/1102papermaking21A.jpg

Foudrinier - schematic http://www.astenjohnson.com/images/images_paper-machine.jpg

Blending of pulp stocks http://www.dkimages.com/discover/previews/767/108027.JPG

Foudrinier papermaking machine

Foudrinier – wet-end

Foudrinier – wet-end

Foudrinier - presses

Foudrinier – dry-end

Foudrinier – calendering and winding

Foudrinier – moisture loss in paper

Papermaking Cylinder machine - thicker paper sheet - slower production speed

Cylinder papermaking machine

Cylinder papermaking machine http://www.zangyeu.com.tw/2007/003.jpg

Schematic of cylinder machine Couch roll Paper layer forms on screen Level of pulp stock vacuum pressure Fibres in suspension Screen rotates Mold remains fixed

Cylinder papermaking machine Dryers

World Paper Production (2012) (x106 metric tonnes) Wrapping, packaging 214.4 and board Coated paper 42.4 Newsprint 30.1