轻化工程漂白Chapter-1

Chapter1TechnicalDevelopmentTendencyofPulpandPaperIndustry1.1GeneralDevelopmentTendencyofPaperScienceandTechnologyLargescale,Automation,Informationality,HighefficiencyOptimizedandsimplifiedprocesssystem,integrationandintelligenceofprocesscontrolReduceinvestmentandenergyconsumption,improveproductqualityanddecreaseproductioncostDevelopgreatlytotherecycledeconomyandcleanproduction,utilizeresourcesmoreefficiently,reduceenvironmentpollution,promotethesustainabledevelopmentofpaperindustry1.2DevelopmentTendencyofChemicalPulpingMainMethods:KraftandSoda-AQMainProcesses:RDH,Super-Batch,EMCC,Lo-Solids,DDSPurposeachieved:HighefficientdelignificationGooddelignifyingselectivityLowenergyconsumptionLessenvironmentalimpactChemicalsused:NaOHNa2SAQPolysulfide(Na2Sn)MinorMethods:SP,AS,NS,AS-AQProductionscale:singleline1milliont/aofwoodpulp3500t/dofwoodpulp750t/dofbamboopulpNewTechnologies:Kvaerner－CompactcookingDualoxtwo－stageoxygendelignificationAndritz－Lo-SolidscookingMetso－SuperBatchcookingOxytractwo-stageoxygendelignification1.3DevelopmentTendencyofMechanicalandChemimechanicalPulpingProcessesused:TMPCTMPBCTMPAPMP,PRC-APMPCMP,Bio-CMPChemicalsused:Na2SO3NaOH,H2O2EnzymeChelatingagents:EDTA,DTPA,DTPMPAPurposeachieved:HighyieldGoodstrengthGoodbrightnessLowpollutionPRC－APMP•P－Preconditioning•RC－Refinerchemical•APMP－AlkalinePeroxideMechanicalPulpProjectsbuiltorbeingconstructed•HunanYueyang100000t/a•HenanPuyangLongfeng100000t/aXinxiangXinya100000t/aJiaozuoRuifeng150000t/a•NingxiaMeili100000t/aPRC－APMPQualityControllablepulpqualitywhichcanmeetthedemandofdifferentspeciesofpaperPoplarPRC－APMP:beatingdegree55－80ºSR（SchopperRiegler）CanadianStandardFreeness（CSF）80-150mLBreakingLength3200m（Max6000m）Brightness78－80％ISO（Max82％ISO）LightScatteringCoefficient45m2/kg（Max54m2/kg）Attheconditionofhighbreakinglength,keepinghighbulk,average2.2cm3/g,max3.0cm3/gLowcontentofshive,average0.1%1.4DevelopmentTendencyofPulpBleachingBleachingsequences:ForChemicalPulp:OQPDQPD(EOP)DOD(EO)P,OD(EP)D,OD(EOP)DC(EP)H,C(EP)HPOHQPForTMP,CTMP,DIP:P,Y,FAS(Formamidinesulphinicacid)PYP-FASStageprobablyused:X,Pa,PxChemicalsused:ClO2O2H2O2NaOH,Na2SiO3DTPA,EDTAPa,Px,PxaXylanaseAdvancedBleachingSequencesGermanyStendalPulpMill0.6M•t/asoftwoodpulp87－89%ISOECF：Q－(OP)－D－(PO)TCF：Q－(OP)－Pa－(PO)SwedenOstrandTCF：Q－(OP)－(ZQ)－(PO)88-90％ISO,Effluentdischarged5-6m3/tpulpFinlandonepulpmillshort－sequencebleaching:D(EOP)D,Brightness85%,88%ISOand90%ISOGuizhouChitianhua:bamboopulpTCF:Q－(OP)－Q－(PO)ECF:Q－(OP)－D－(PO)Purposeachieved:HighbrightnessHighbrightnessstabilityHighbleachedpulpyieldLowviscositylossLowenergyandwaterconsumptionLowpollutionload(COD,BOD,SS,AOX)1.5DevelopmentTendencyofWastePaperRecyclingDrumPulper:lowshearforce,highconsistency15-18%HighefficientscreeningandcleaningScreeningwithlowandmediumconsistency,slot≤0.15mmCleanerforheavyorlightcontaminantsEffectiveremovalofstickiesHighefficientdispersingtechniqueHighefficient,lowenergyconsumptionfloatationequipmentOxidative－reductivebleaching:P、Y、FASorcombinedHighefficientwastewatertreatmentsystemFreshwaterconsumption≤5m3/tpulp1.6DevelopmentTendencyofPapermakingForpapermaking,stressonthedevelopmentofproductiontechniquescharacterizedbylowbasis-weight,highquality,lowconsumptionandhighefficiencyForpapermachineandpaperboardmachine,turntowardswidewidth,highspeed,highefficiency,lowconsumption,andtheincreaseofunitproductioncapacityaswellasthenewtechniqueofpapersurfacetreatment.(b)Purposesachieved:ImprovementofpapermachinerunnabilityIncreaseofpaperandpaperboardproductionImprovementofproductqualityEnhancementofenterprisecompetitivepowerPapermachineMaxwidthofnewsprintmachineandsupercalender:11.3mClosedoperationfromsheetformationtodrying,automaticsheettransferring,automaticreelchangingChangesofcoatingandcalenderingfromoutermachinetoinnermachineEnergyandwatersavingNewsprintstreamconsumption1.1－1.4t/twaterconsumption10－12m3/tImprovedqualityFuturedevelopmentfocusonhigherspeed,butnowiderThepapermachinespeedwillreach3000m/mininthenext10yearsNewtechniquesinculturepapermachineHighefficient,compactstockflowsystemSmallervolume,shorterflowpath,bettermixinganddegassing,moreaccuratefurnishandconsistencycontrolHydraulicheadboxwithdilutedwatercrossbasisweightcontrolNewgenerationoftwinwireformerwithvacuumformingrollandpressurizeddewateringplateShoepressIncreasethemachinespeedto1500m/min→1800m/minIncreasethedrynessofwetweb3~8%Savethedryingenergy12－32％Improvebulk,crossmoistureprofileDryingTechniqueSinglerowdryerRopefreesheettransferringSinglefelt(dryscreen)operationImprovetheuniformityofcrossshrinkageIncreasedryingcapacityCoatingandCalenderingTechniquesMergepapermaking,coatingandcalenderingintoamachine,realizetheon-lineproductionofcoatedpaperPremeasurementsizingpressDoublerollsoftcalenderingtechniqueSupercalendercoveredwithpolymerCurtaincoating,spraycoatingEngineeringpigment,nanometerpigment(c)TechnologiesandproductsfocusedonHighefficiency,lowenergyconsumption,mediumconsistencypulpbeating(especiallyfornon-woodandrecycled