轻化工程漂白Chapter-1

1、Chapter 1 Technical Development Tendency of Pulp and Paper Industry 1.1 General Development Tendency of Paper Science and TechnologylLarge scale, Automation, Informationality, High efficiencylOptimized and simplified process system, integration and intelligence of process controllReduce investment a

2、nd energy consumption, improve product quality and decrease production costlDevelop greatly to the recycled economy and clean production, utilize resources more efficiently, reduce environment pollution, promote the sustainable development of paper industry1.2 Development Tendency of Chemical Pulpin

3、gMain Methods: Kraft and Soda-AQMain Processes: RDH, Super-Batch, EMCC, Lo-Solids, DDSPurpose achieved: High efficient delignification Good delignifying selectivity Low energy consumption Less environmental impactChemicals used: NaOH Na2S AQ Polysulfide (Na2Sn)Minor Methods: SP, AS, NS, AS-AQProduct

4、ion scale: single line 1 million t/a of wood pulp 3500 t/d of wood pulp 750 t/d of bamboo pulpNew Technologies: KvaernerCompact cooking Dualox twostage oxygen delignification AndritzLo-Solids cooking MetsoSuper Batch cooking Oxytrac two-stage oxygen delignification 1.3 Development Tendency of Mechan

5、ical and Chemimechanical PulpingProcesses used:TMPCTMPBCTMPAPMP, PRC-APMPCMP, Bio-CMPChemicals used:Na2SO3NaOH, H2O2EnzymeChelating agents: EDTA, DTPA, DTPMPAPurpose achieved: High yieldGood strengthGood brightnessLow pollutionPRCAPMP PPreconditioning RCRefiner chemical APMPAlkaline Peroxide Mechani

6、cal PulpProjects built or being constructed Hunan Yueyang 100000 t/a Henan Puyang Longfeng 100000 t/a Xinxiang Xinya 100000 t/a Jiaozuo Ruifeng 150000 t/a Ningxia Meili 100000 t/aPRCAPMP QualitylControllable pulp quality which can meet the demand of different species of paperlPoplar PRCAPMP: beating

7、 degree 5580SR（Schopper Riegler） Canadian Standard Freeness （CSF）80-150mLlBreaking Length 3200m （Max 6000m）lBrightness 7880ISO （Max 82ISO）lLight Scattering Coefficient 45m2/kg （Max 54m2/kg）lAt the condition of high breaking length, keeping high bulk, average 2.2 cm3/g , max 3.0 cm3/glLow content of

8、shive, average 0.1% 1.4 Development Tendency of Pulp BleachingBleaching sequences:For Chemical Pulp:OQP DQP D(EOP)D OD(EO)P, OD(EP)D, OD(EOP)D C(EP)H, C(EP)HP OHQP For TMP, CTMP, DIP: P, Y, FAS (Formamidine sulphinic acid) PYP-FASStage probably used: X, Pa, PxChemicals used: ClO2O2H2O2NaOH, Na2SiO3D

9、TPA, EDTAPa, Px, PxaXylanaseAdvanced Bleaching SequenceslGermany Stendal Pulp Mill 0.6Mt/a softwood pulp 8789%ISO ECF：Q(OP)D(PO) TCF：Q(OP)Pa(PO)lSweden Ostrand TCF：Q(OP)(ZQ)(PO) 88-90ISO, Effluent discharged 5-6m3/t pulplFinland one pulp mill shortsequence bleaching :D(EOP)D, Brightness 85%, 88%ISO

10、and 90%ISOlGuizhou Chitianhua: bamboo pulp TCF: Q(OP)Q(PO) ECF: Q(OP)D(PO)Purpose achieved: High brightnessHigh brightness stabilityHigh bleached pulp yieldLow viscosity lossLow energy and water consumptionLow pollution load (COD, BOD, SS, AOX)1.5 Development Tendency of Waste Paper RecyclinglDrum P

11、ulper: low shear force, high consistency 15-18%lHigh efficient screening and cleaning Screening with low and medium consistency, slot0.15mm Cleaner for heavy or light contaminants Effective removal of stickieslHigh efficient dispersing techniquelHigh efficient, low energy consumption floatation equi

12、pmentlOxidativereductive bleaching: P、Y、FAS or combinedlHigh efficient waste water treatment system Fresh water consumption 5m3/t pulp1.6 Development Tendency of Papermaking For papermaking, stress on the development of production techniques characterized by low basis-weight, high quality, low consu

13、mption and high efficiency For papermachine and paperboard machine, turn towards wide width, high speed, high efficiency, low consumption, and the increase of unit production capacity as well as the new technique of paper surface treatment.(b) Purposes achieved:Improvement of paper machine runnabili

14、tyIncrease of paper and paperboard productionImprovement of product qualityEnhancement of enterprise competitive powerPaper machineuMax width of newsprint machine and supercalender: 11.3muClosed operation from sheet formation to drying, automatic sheet transferring, automatic reel changinguChanges o

15、f coating and calendering from outer machine to inner machineuEnergy and water saving Newsprint stream consumption 1.11.4t/t water consumption 1012 m3/tuImproved qualityuFuture development focus on higher speed, but no wider The paper machine speed will reach 3000m/min in the next 10 yearsNew techni

16、ques in culture paper machineuHigh efficient, compact stock flow system Smaller volume, shorter flow path, better mixing and degassing, more accurate furnish and consistency controluHydraulic head box with diluted water cross basis weight controluNew generation of twin wire former with vacuum formin

17、g roll and pressurized dewatering plateuShoe press Increase the machine speed to 1500m/min1800m/min Increase the dryness of wet web 38% Save the drying energy 1232 Improve bulk, cross moisture profileDrying TechniqueuSingle row dryeruRope free sheet transferringuSingle felt (dry screen) operationuIm

18、prove the uniformity of cross shrinkageuIncrease drying capacityCoating and Calendering TechniquesuMerge papermaking, coating and calendering into a machine, realize the on-line production of coated paperuPremeasurement sizing pressuDouble roll soft calendering techniqueuSupercalender covered with p

19、olymeruCurtain coating, spray coatinguEngineering pigment, nanometer pigment(c) Technologies and products focused on High efficiency, low energy consumption, medium consistency pulp beating (especially for non-wood and recycled pulp) New technique of producing high grade, light-coated writing and pr

20、inting paper (offset newsprint, offset printing paper, light-weight coated paper, Chinas art paper, etc) Coating formation and advanced coating technology of paper and paperboard New technique of producing high grade packaging paper and paperboard (coated folding board, coated white board, Kraft lin

21、er board, high strength corrugating medium, etc) Advanced technology of producing specialty paper, functional paper product and paper-base composite (carbonless copy paper, thermosensitive paper, pressure sensitive paper, computer-printing paper, special synthetic paper, pulp mould products) Advance

22、d technology of producing high grade tissue paper and disposable products(d) Paper Chemicals used:l lSizing agents Dispersing rosin sizeAlkyl ketone dimmer (AKD)Alkenyl succinic anhydride (ASA)l lWhite mineral pigmentsCalcium carbonate( GCC, PCC)Titanium dioxideKaolinTalcl lPaper strength agentsStar

23、ch (OS, CS, AS, AmS)PAM (CPAM, APAM, AmPAM)PVA (Polyvinyl alcohol)PAE (Polyamideamine-epichlorohydrine)PEI (Polyethyleneimine)l l Retention-aids and drainage-aidsCompozilTMCPAMAPAMCS (Cationic Starch)PEO (polyethylene oxide)PEO/CF (co-factor)Some Co-factors: PFR (phenolformaldehyde resin) MPFR (Modi

24、fied phenolformaldehyde resin) SNS (Sodium naphalence sulphonate)1.7 Development Tendency in Pollution Control and Environmental ProtectionMore and more attention will be paid in pollution control and environmental protection in the future. 3RReduce,Reuse,RecyclePulp and paper clean production Alkal

25、i recovery from black liquor of both wood and non-wood pulpBiorefinery- a new way of fully utilization of plant fiber resources Lignin modification and utilization Treatment and utilization of solid-waste Treatment of screening, cleaning and bleaching effluent with coagulating-biochemical process Treatment and reusing of white water in paper making process1.8 Development Tendency in Process Energy Saving and Carbon Reducing Energy saving and heat recovery in chemicol pulping Energy saving and heat recovery in mechanical pulping and chemimechanical pulping Energ