environmental standards in the pulp and paper sector

Environmental standards in the Pulp and Paper Sector

Almut Reichart German Federal Environment Agency

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“BAT in textile and pulp and paper sector” – 18th – 29th November 2013 A. Reichart, Umweltbundesamt

Outline

Overview over the pulp and paper industry in Europe

Status of the BREF Pulp & Paper Industry

Structure of the BREF

Examples for Best Available Techniques for Recovered Paper Processing, Papermaking and related Processes

Concluding remarks

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Overview over the European Pulp and Paper sectorShare of world Paper & Board production - development 2000-2010 (Cepi 2012, RISI)

Worldwide paper production: 370 mio. tEurope: 104,8 mio. tGermany: 22 mio. t

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Overview over the European Pulp and Paper sector

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Environmental issues of the sector in Europe Increase of production by 50% electricity consumption, primary

energy consumption have increased

The water consumption and some emissions like and NOxand CO2 emissions stay around the same high level

other emissions are decreasing significantly like COD, SO2, BOD, AOX

Substantially environmental improvements in the production have lead to a partially decoupling of environmental impacts from the production

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Best Available Techniques (BAT) Reference Document for the Production of Pulp, Paper and Board

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Status and scope of the BREF Pulp and Paper

The BREF Pulp and Paper Industry is the major outcome of the European information exchange on BAT for the sector

The BREF provides a lot of information on available techniques.

Information source for permitting authorities, public, and operators

First Edition BREF Pulp and Paper was published in 2001

First Revision of the document will be published in 2014

• Final draft from July 2013• Technical discussion is finalized• Political adoption in 1st. Quart. 2014

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Scope and status of the BREF Pulp and Paper industry

Related activities:• Power and steam

generation

• Raw water treatment

• Waste water treatment

• Waste handling and on-site treatment

• Storage and handling of chemicals

Download of the BREF: http://eippcb.jrc.ec.europa.eu/reference/BREF/PP_BREF_FD_07_2013.pdf

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The structure of the BREF

Best available techniques (BAT) conclusions (chapter 8)

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Examples for BAT in recycled fibre paper mills

1. Water use and waste water management2. Fibre recovery from paper machine effluents3. End of pipe - waste water treatment4. Waste management, incineration of residues5. Energy efficiency

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1. Water and waste water management

BAT 5: In order to reduce fresh water use and generation of waste water, BAT is to close the water system to the degree technically feasible in line with the pulp and paper grade manufactured by using a combination of the techniques….

• Monitoring an optimisation of water use• Evaluation of recirculation options • Balancing the degree of closure of water circuits and potential draw

backs • Separation from less contaminated waters and reuse, e.g. sealing

water from pumps, cooling water• In line treatment of process water to improve water quality to allow

recirculation

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BAT 5: associated environmental performance levels for the waste water flow at the point of discharge

subsector BAT –AEPL in m³/ Air dried ton

Recycled fibre (RCF) paper mills without deinking

1.5 ‐ 10

RCF paper mills with deinking

8 ‐ 15

RCF‐ based tissue mills with deinking

10 ‐ 25

non‐integrated paper mills

3.5 ‐ 20

Techniques to reduce fresh water consumption:a. Separation of the water systemsb. Countercurrent flow of process water and

water recirculationc. Partial recycling of treated waste water after

biological treatmentd. Clarification of white watere. Continuous control of process water qualityf. Prevention of biofilms by using methods that

minimise emissions of biocidesg. Removal of calcium by a controlled

precipitation of calcium carbonate

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Example: Separation of water loops and counter current flow Countercurrent flow: White water goes into

the opposite direction than the product flow In many paper mills fresh water is only used

for dilution of chemicals and at the paper machine for clean spray pipes and edge sprays

Short circulation on the paper machine Long circulation to the stock preparation Separation is done by thickeners (e.g.

filtration, wire and presses) Save-alls are filtration (e.g. microfiltration),

flotation (dissolved air flotation) or sedimentation units to clean the water from fibers etc.

Advantages: less water consumption, (RCF without deinking 2-6

m³/t, RCF with deinking below 10 m³/t) Lower volumes for effluent treatment, decreased fibre an filler losses, elevated process temperature reduced energy

demand

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Example: In-line biological process water treatment for closed water loop

1 mill Germany Production of 400.000 t/a case material and testliner, 2 paper machines, zero effluent

Partial stream of process water is cooled preacified anaerobic reactors (UASB) (optional decarbonisation stage) aerobic treatment sedimentation sand filter COD concentration in the water circuit 7 000 – 8 000 mg/l

Benefits: less excess sludge, energy for aeration can be saved, Biogas from anaerobic treatment can be used for steam production on site

Risks: uncontrolled precipitation of calcium, optimisation of water-fibre system is complex and needs years

Costs: capital and operational costs total EUR 1.8/ton paper and 0.7/m³ process water

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2. Efficient fibre and filler recovery (BREF sec.7.3.4)

1. Screening in stock preparation and recycling to pulping unit2. Short water circulation in paper machine, reuse of untreated water

containing not-retained fibres3. Wet end save alls (drum or disc filter, flotation, microfiltration,

sedimentation) collection of fibres in a chest recycling to paper machine or next lower quality unit

4. Wet and dry end broke handling recycling5. Further integrated measures:

1. Tuning of refining and screening (heavy refining increases amount of short fibres)2. Control of even paper web across the machine width3. Efficient use of chemical additives for better retention of fibres4. Suitable size of white water and broke storage (run of 2-3 hours production) equals

out sudden peak fibre discharges5. Collection and recycling of broke after the coating unit

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Example: efficient fibre and filler recovery

Achievable min. solid losses: 10 – 20 kg/t produced paper

(i.e. 1 – 2% loss)

Benefits: return of raw material to the

process, less waste to dispose, improved runability of paper

machine, lower solid content in the

excess water for treatment

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Example: Cleaning and recycling of white water -Dissolved Air filtration (DAF)

Cleaning of white water for recycling

Anionic trash and fines are agglomerated into physically treatable flocs

The suspended solids are attached to air bubbles to the surface of a basin scraped off dewatered incineration

Clarified water is taken from the bottom recirculated to a suitable place in the water cycle

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Diskfilter

DENSIDISC ® is a product by O.M.C. Collareda Srl - Div. Aqua Engineering.

Stainless steel gravity filter, filtering by metal wire

Application Solids separation from liquids Fibres separation from fillers and

fines Sludge and supension thickening Effluent filtration Pulp thickening in stock preparation

Rotation of disks provides friction for cleaning action and preventing the wire clogging

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Example Microfiltration unit (ALGAS)

Corrugated surface increasing filtration area

Inside to outside filtration, slowly turning drum (stainless steel), small motor, no vacuum

Cleaned by full width showers

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Example: other Membrane filtration

Efficient removal of suspended solids from white water is a prerequisite for further recirculationof treated water to production and a preliminary measure for closing up water circuits.

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3 . Emissions to water – waste water treatment

BAT 13-16 and BAT 43 – 49 are relevant BAT is to substitute chemical additives with high nutrient contents

(nitrogen, phosphorus) Pretreatment of effluents containing coating colors Optimised fibre, filler and pigment recovery In order to reduce emissions of pollutants into receiving waters, BAT is

to use: 1. primary (physico- chemical) treatment and2. secondary (biological) treatment

When further removal of organic substances, nitrogen or phosphorus is needed, BAT is to use tertiary treatment (e.g. filtration, flocculation/precipitation or advanced oxidation processes)

Proper design and operation and control of WWTP is BAT

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BAT AELs for RCF mills - emissions to water

Parameter RCF with deinking in kg/t as yearly average

RCF without deinking in kg/t as yearly average

Chemical oxygen demand (COD)

0.4 ‐ 1.4 0.9 – 3.0(4.0 for tissue)

Total suspend solids (TSS) 0.02 – 0.2 0.08 – 0.3(up to 0.4 for tissue)

Total nitrogen 0.008 – 0.09 0.01 – 0.1(up to 0.15 for tissue)

Total phosphorus 0.001 – 0.005 0.002 – 0.01 (up to 0.015 for tissue)

Adsorbable organically bound halogens (AOX)

0.05 for wet strength paper 0.05 for wet strength paper

For mills with closed water circuits, there are no emissions of COD.The BOD concentration in the treated effluents is expected to be low (around 25 mg/l as 24‐hour composite sample)

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modified by A. Reichart original source: Efinger D., Der R2S-Reaktor – Funktion und erste Erfahrungen; IN: PTS-Seminar „Betrieb biologischer Abwasserreinigungsanlagen – Anaerobtechnologieund Betrieb von Anaerobanlagen“, 13. – 14.10.2008, PTS München, PTS-Manuskript AR 819, G. Weinberger, H.-J. Öller (Hrsg.)

COD[mg/l]

10 20

15.000

4.000

2.000

DIP, white, newsprint, SC

brownpaper

TissueDIP, Mixed, without DIP Speciality p.,

primary fibre

Ca2+

[mg/l]

1.200

600

300

53specific water consumption in l/kg

Choice of biological waste water treatment technique depends on the kind of paper produced

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Example: Anaerobic biological waste water (pre)-treatment

When concentrations are high > 1.000 mg/l COD, and SO4 is low (<1000 mg/l) anaerobic treatment works economically

Typical reactors: • Upflow anaerobic sludge blanket (UASB)• Extended granular sludge blanket (EGSB), e.g. internal current (IC) or BIOBED

reactor Advantages: reduction of organic pollution load compared to only

aerobic treatment, less excess sludge (minus 70 %) and less energy consumption, biogas production (400 – 600 m³/t COD removed)

Draw backs: sulphate reduction to sulfite is a potential inhibitor of methanogenesis, reduction of biogas production

Effluent of an anaerobic reactor never has sufficient quality for direct discharge aerobic treatment has to follow (activated sludge reactor)

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Example: Chlorine free bleaching chemicals for recycling fibres processing mills

reduction of AOX was achieved by a combination of several measures

the use of molecular chlorine has been completely replaced by chlorine dioxide and the use of chlorine-free bleaching chemicals such as molecular oxygen, hydrogen peroxide, ozone or peracetic acid.

RCF – Bleaching: Reductive bleaching: Na2S2O4 sodiumdithionite, pH < 6Oxidative beaching: H2O2 hydrogenperoxide, pH > 8 Complexing agents stabilise H2O2

AOX emissions are below 10 g/t product

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4. Waste management, treatment of residues

“Waste material is simply raw material in the wrong place”BAT 12 is to implement a waste assessment and management so

as to facilitate 1. waste reuse, 2. waste recycling, or 3. other recovery, including a combination of the following techniques:

a. Separate collection of different fractionsb. Merging suitable fractions for better utilisationc. Pretreatment before reuse or recycling ( e.g. dewatering, shredding,

biological stabilisation)d. Recovery or recycling on site (e.g. fibre or coating recovery)e. Energy recovery on- or offsite from wastes with high organic contentf. External material utilisationg. Pretreatment of waste before disposal

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Waste management, treatment of residues

Council Directive 99/31/EC dumping of waste with organic content > 5% is not allowed

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Example: incineration of residues with high calorific value

Incineration combined with power and steam generation is environmental and economically attractive

Pretreatment of rejects is necessary: dewatering (50% SC), crushing, screening

RCF mills with deinking have high amounts of deinking sludge, and process water treatment sludge up to 40% residue related to input material

Sludge contains: short fibres, fillers, coatings, ink particlesDifferent types of incineration possible e.g.:

• Separate mill reject incineration plant• Co-incineration in on-site coal fired power plants• Co-Incineration off-site in the cement or brick industry

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Example: Incineration of residues - pretreatment of rejects

grate firing5 -25 MW heat capacity

fluidised bed firing25 MW heat capacity

Mixed systems are also possible

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2012

Magnetseparator

Screwpress

Disc filter

Screwpress

Shred-ding

Screen

MagnetSeparator (NE)

Silo fibersludge

Silo Coarserejects

Gravity table

SPP Screens & cleaner rejects

Surplus aerationbiosludge

Mill´s U-drain

Pre Shredding

SPP Pulperrejects

PulperRagger

SPP= Stock Preparation Plant

Example SIPAPER Rejekthandling - source: Siemens AG 2012 Dr. H Schwarz

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Example: Reject Split feeded to Reject Power at Saica UK

Coarse Rejects(mainly Plastics):50% of total rejectsLHV: ca.13000kJ/kgSC: 55% - 60%Mech. Dewatering via Screw presses andmech. preparation

Biosludge:20% of sludgeamountLHV: < 300kJ/kgSC: 50 - 55%Mech. Dewatering w/ fiber sludge

Fiber rejects :80% of sludgeamountLHV: ca. 5000kJ/kgSC: 50 - 55%

Capacity of solid reject fuel: ca. 80.000 t/aBased on 2010 planning data

Biogas of AnaerobicEffluent treatment:Ca. 5MWth max. , Ca.65% Methane, 30% CO2, biologicaldesulfurisation

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Example: SIPAPER Reject Power Technology

TechnologyReject Power Firering source : Siemens AG Dr. H Schwarz 2012

EconomiserBoiler

Cyklon

Grate

Spin wheel

Bag filter

Fuel-dosing

2 sec. Residence Time Pilot unit

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Example incineration of rejects - flue gas treatment

Flue gas needs treatment: Flue gas recirculation

SNCR (urea injection) NaHCO3, coal and zeolite

are added as adsorbensfor acid gas, dioxins, furans

bag filter continuous monitoring of

dust, SO2, NOx, TOC, HCl

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Advantages of reject incineration

No landfillUtilisation of high heating value of residues 22- 24 MJ/kgAsh can by used in road constructionSteam generationLow emissionssavings of 1.3 EURO /aInvestment cost: 6 mio. EURO + 0.6 mio. EURO/a operation

(for treatment plant treating 15.000 t/a) Refer also to BREF section 6.3.14

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5. Energy consumption and efficiency

BAT 6 Implementation of an energy management system e.g. ISO 50001• Incineration of residues with high calorific value• Use as far as possible the cogeneration of heat and power (CHP) • Use of excess heat for the drying of biomass, sludge, process water, buildings• Use thermo compressors• Insulation of steam and condensate fittings

BAT 46: • high consistency pulping for disintegrating RCF into separate fibres• efficient coarse and fine screening smaller equipment with lower energy consumption• Extracting impurities as early as possible

BAT 53: • best practice refining with heat recovery,• Optimised vacuum system for dewatering in the press section• Condensate recovery and efficient exhaust air heat recovery system,• Optimised pumping design, • Steam box heating of the paper web• Use of high efficiency motors• Preheating shower water with a heat exchanger• Use waste heat for sludge drying• Heat recovery from axial blowers, Yankee hood, infrared exhaust air (if used)

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Example: Energy consumption assessment and optimisation

1. Assessment of the initial situation

2. method for locating, quantify of potentials and optimizing

3. Monitoring and sustainable safeguarding of achieved savings

MeasuresMeasures

RealisationRealisation

Data

acquisition

Tools

Potential assesmentPotential

assesmentConsumption valuesConsumption values

Purpose / functionPurpose / function

Process flowsProcess flows

Technical equipmentTechnical equipment

Waste heatWaste heat

Heat sinksHeat sinks

Distribution networkDistribution network

Process managementProcess management

Functional assessmentFunctional assessment

Pinch analysisPinch analysis

BenchmarkingBenchmarking

EfficienciesEfficiencies

Heat networkHeat network

Compressed airCompressed air

Refrigerating plantsRefrigerating plants

Dewatering performanceDewatering performance

Drives for pumpsDrives for pumps

RefiningRefining

Vacuum systemVacuum system

Steam & condensatesystem


Hood ventilationHood ventilation

Hall ventilationHall ventilation

Power plantPower plant

Focal

analysis

points

EconomicassessmentEconomic

assessment

Action planAction plan

Assessment &

optimisation

MeasuresMeasures

RealisationRealisation

Data

acquisition

Tools

Potential assesmentPotential

assesmentConsumption valuesConsumption values

Purpose / functionPurpose / function

Process flowsProcess flows

Technical equipmentTechnical equipment

Waste heatWaste heat

Heat sinksHeat sinks

Distribution networkDistribution network

Process managementProcess management

Functional assessmentFunctional assessment

Pinch analysisPinch analysis

BenchmarkingBenchmarking

EfficienciesEfficiencies

Heat networkHeat network

Compressed airCompressed air

Refrigerating plantsRefrigerating plants

Dewatering performanceDewatering performance

Drives for pumpsDrives for pumps

RefiningRefining

Vacuum systemVacuum system



Hood ventilationHood ventilation

Hall ventilationHall ventilation

Power plantPower plant

Focal

analysis

points

EconomicassessmentEconomic

assessment

Action planAction plan

Assessment &

optimisation

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Energy consumption and efficiency

Type of RCF paper mill Energy consumption level for process heat in kWh/t

Energy consumption level for electricity in kWh/t

RCF without deinking ( packagingpaper, e.g. testliner and /or corrugated medium)

1100 ‐ 1500 350 ‐ 450

RCF without deinking (cardboard or folding boxboard(1) coated and uncoated)

1200 ‐ 1600 400 ‐ 500

RCF with deinking (graphic paper, e.g. newsprint (1)

1 000 – 1800 900 ‐ 1300

RCF with deinking (folding boxboard) (1)

1 000 – 1100 450 ‐ 550

(1) Figures refer to mills that do not produce mechanical pulp on‐site

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Example: Energy saving screening techniques

Energy saving screens: Hole screens with multi stage

fine screening with higher consistency from 1.5 to 2.5 %lower water content to press section less energy demand for drying

Higher separation efficiencies lower rotations speed needed less electrical power demand

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Example: Use of steam boxUsed to heat up paper web for

improved drainage properties of the web for higher dewatering capacities of the following press

The alternative would be to increase the white water temperature by direct steam heating

Advantage: only a small amount of water has to be heated not the whole white water circuit

Savings 4 % reduction of specific energy consumption

Investment 600.000 EUROPayback 2.6 a

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Thank you for your attention!

[email protected]

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Useful links

BREF for the Production of Pulp, Paper and Cardboard: http://eippcb.jrc.ec.europa.eu/reference/pp.html

Cleaner production Germany:http://www.cleaner-production.de/en.html

Blue Angel for paper products: http://www.blauer-engel.de/en/products_brands/search_products/produkttyp.php?id=434http://www.blauer-engel.de/en/products_brands/search_products/produkttyp.php?id=459

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Papermaschine

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AOX content in wet strength agents based on Epichlrohydrinefrom research projects – PTS

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Deinking

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Progress of the paper industry – reduction in emissions reached so far

Source: CEPI Annual statistics 2012

environmental standards in the pulp and paper sector

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