Wood 120 Pulp and Paper 2013

Transcript Wood 120 Pulp and Paper 2013

WOOD 120 Pulp and Paper 1

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 5

Lignin “glues” wood cells together

wood fibers or fiber bundles

Pulping

Mechanical • Uses heat and mechanical energy • Higher yield • Lower quality Chemical • Uses heat and chemical energy • Lower yield • Higher quality 8

World Pulp Production (2012) (x10 6 metric tonnes) • Recovered paper • Mechanical pulp • Full chemical pulp Kraft 94.7

Sulphite 3.4

212.8

28.9

98.1

• Dissolving pulp • Non-wood fiber pulp 4.9

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

wood fibers or fiber bundles

Mechanical Pulping

• Stone ground wood • Refiner pulps 16

Debarking

Drum debarkers

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

Stone Ground Wood 19

Stone Ground Wood

• Raw material – short logs (bolts) • High yield • Low quality fibers or fiber bundles • High energy input • Pulp suitable for tissues 20

Refiner pulping 21

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 25

The “Alphabet Pulps”

• RMP • TMP refiner mechanical pulp thermo mechanical pulp • CTMP chemi thermo mechancial pulp • SGW • PGW stone ground wood pressurized ground wood • NSSC neutral sulfite semi chemical 26

Chemical pulping

wood individual fibers

Chemical Pulping

•Sulfate process (Kraft) •Sulfite process 28

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 29

Kraft digester - continuous http://www.outokumpu.com/35127.epibrw

http://us.magnetrol.com/Images/Applications/PulpDigester.jpg

Kraft pulping – continuous digester 1. Chips and pulping chemicals 2. Steam 3. Blow valve 4. Gases 5. Pulp 31

White liquor Wood

Kraft liquor recovery cycle

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

Pulp treatment

• Bleaching / Brightening • Beating (refining) 33

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

Bleaching • 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 37

Bleaching/brightening chemicals • C • D • O chlorine chlorine dioxide oxygen • Z ozone • P peroxide • E alkaline extraction Cl 2 ClO 2 O 2 O 3 H 2 O 2 NaOH 38

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 39

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 41

Pulp Beating

Jordan refiner 42

Pulp Beating

Before beating After beating Internal and external defibrillation take place 43

Papermaking

Foudrinier machine - thinner paper sheet - faster production speed Cylinder machine - thicker paper sheet - slower production speed 44

Papermaking

• Foudrinier machine - thinner paper sheet - faster production speed 45

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 - presses

Foudrinier – dry-end

Foudrinier – calendering and winding

Foudrinier – moisture loss in paper

Papermaking

• Cylinder machine - thicker paper sheet - slower production speed 55

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 Mold remains fixed Screen rotates 58

Cylinder papermaking machine Dryers

World Paper Production (2012) (x10 6 metric tonnes) • Wrapping, packaging and board • Coated paper • Newsprint 214.4

42.4

30.1