990 likes | 1.78k Views
WOOD 120 Pulp and Paper. Paper products. Raw material. Chemical pulp mill. http://w3.upm-kymmene.com/upm/internet/cms/upmmma.nsf/lupGraphics/Botnia_Fray%20Bentos%20mill_1.jpg/$file/Botnia_Fray%20Bentos%20mill_1.jpg. Chemical pulp mill.
E N D
Paper products Raw material
Chemical pulp mill http://w3.upm-kymmene.com/upm/internet/cms/upmmma.nsf/lupGraphics/Botnia_Fray%20Bentos%20mill_1.jpg/$file/Botnia_Fray%20Bentos%20mill_1.jpg
Chemical pulp mill http://www.metsopaper.com/paper/MPwGeneral.nsf/WebWID/WTB-061228-2256F-E7612/$File/Total_scope_with_large_text.jpg
Composition of Paper Surface Section through paper sheet
Pulping Mechanical • Uses heat and mechanical energy • Higher yield • Lower quality Chemical • Uses heat and chemical energy • Lower yield • Higher quality
World Pulp Production (2012)(x106 metric tonnes) • Recovered paper 212.8 • Mechanical pulp 28.9 • Full chemical pulp 98.1 Kraft 94.7 Sulphite 3.4 • Dissolving pulp 4.9 • Non-wood fiber pulp 16.1
Raw material – wood supply Logs Chips http://www.partonlumber.com/images/000_0334.jpg www.panoramio.com/photos/original/3042908.jpg http://www.unitedeagle.cn/upimages/20083311435587662.jpg
Pulp and Paper – overview of production stages http://www.energysolutionscenter.org/gasirpaper/Images/PaperManfLine.jpg
Pulping http://www.energysolutionscenter.org/gasirpaper/Images/PaperManfLine.jpg
Pulp treatment http://www.energysolutionscenter.org/gasirpaper/Images/PaperManfLine.jpg
Papermaking http://www.energysolutionscenter.org/gasirpaper/Images/PaperManfLine.jpg
Mechanical pulping fibers or fiber bundles wood
Mechanical Pulping Stone ground wood Refiner pulps
Debarking Drum debarkers
Stone Ground Wood bolts of wood hydraulic pistons grinding stone pulp slurry http://chempatec-auhorn.com/images/pressurizedmechanicalpulpproduction001_480.jpg
Stone Ground Wood • Raw material – short logs (bolts) • High yield • Low quality fibers or fiber bundles • High energy input • Pulp suitable for tissues
Refiner pulping http://www.globalequip.com/photos/bg_901371.001_2.jpg http://www.triple-r.co.nz/pop/pop_pulp09.html
Multiple refiners in parallel http://www.metsopaper.com/paper/MPwFiber.nsf/WebWID/WTB-041123-2256F-3E65B/$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 individual fibers wood
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 Bleaching Washing Evaporation Cauticising Bailing & Shipping Black liquor Green liquor Burning Green liquor recovery cycle
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
Paper products Raw material
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
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