Transcript Techniques to consider in the determination of BAT - IQ

PULP AND PAPER INDUSTRIES
Group 4
Cynthia Alcántara
Lucía Escorial
Sara Gómez
Michael Moreau
Marta Pérez
General Information
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
• Main consumer of natural resources:
– Wood (as raw material)
– Fossil, fuel, electricity (as energy)
– Water
• Wood contains:
– 50% water
– 45% cellulose
– 25% hemicelluloses
– 25% lignin
– 5 % other organic a inorganic materials
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Classification of pulp and paper
mills
•Kraft pulping process
• Sodium sulphate
•Sulphite pulping process:
• Magnesium sulphite pulping
•Mechanical and chemi-mechanical
• mechanical energy applied to the wood
matrix
•Recycled fibre processing (recovered fibre)
•Non integratepaper mills
• paper manufacturing independently
from pulp manufacturing.
Non integratepaper mills
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
• Paper and board manufacturing is described
independent from pulp manufacturing.
•Most paper mills in Europe are nonintegrated mills.
•All types of paper and board-making
processes have the following basic units:
• Stock preparation
• Approach flow system
• Paper and board machine
• Calenders, coaters, a coating colour kitchen,
winders, rewinders and a roll wrapping station.
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Applied Processes and
Techniques
• Stock preparation
• Is conducted to convert raw stock into finished
stock
• The pulp is prepared for the paper machine
• Including the blending of different pulps,
dilution and the addition of chemicals
• Is based on the removal of impurities
•Paper machine
• The paper is formed
• Most of the properties of the paper are
determined.
Applied Processes and
Techniques
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
•Water circuits and fibre recovery
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3 process water circuits in a paper mill:
primary circuit (short circulation)
secondary circuit (long circulation)
tertiary circuit (excees water from secondary)
• Broke system
• Return the paper fibre back to the process
• The amount of broke produced during
papermaking is normally 5 - 20 % of the
machine capacity
• Wet broke: normal operation
• Dry broke: in finishing operations
Introducción
Introduction
Classification
Process
Consumption
Techniques
Applied Processes and
Techniques
•Sizing (optional)
• agents are applied to the fibre matrix to
increase the strength of the base paper
• and tomodify the surface properties with
respect to liquid uptake during writing,
printing or coating
•Coating (optional)
BAT
Emerging
• application of a mixture of water, white
pigments, binder…to create specific surface
qualities
•Dyeing (optional)
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
• For coloured papers
Introducción
Introduction
Classification
Process
Consumption
Applied Processes and
Techniques
•Addition of chemicals
• To achieve certain paper properties
• To improve operations in the production
process
•Calendering (optional)
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
• The objective is to produce a smooth paper
surface that meets the printing and writing
requirements for the intended use.
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Consumption and emission levels
• Consumption of major raw material
–Fibres, water and chemical additives
• Water use
–Cleaning water, solvent, cooling …
• Use of additives
• Energy demand
• Wastewater emissions:
–Rejects from stock cleaning
–Temporary and accidental discharges
–Cooling and sealing waters
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Consumption and emission levels
•Solid waste generation wastewater:
–Rejects from stock preparation
–Sludge from water treatment
•Atmospheric emissions:
–Air emissions from paper machines
–Air emission from energy generation
–Odour from vapours and from wastewater
treatment
•Noise from paper machines (local)
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Techniques to consider in the
determination of BAT
•Techniques currently commercially available
for prevention or reduction of:
– emissions/waste
–reducing consumption of energy
–reducing consumption of raw materials
1) Internal treatment of white water by use of
membrane filtration and recycling of treated process
water
–Micro-filtration
–Ultra-filtration
–Nano-filtration (NF)
–Reverse osmosis (RO)
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Techniques to consider in the
determination of BAT
2) Water management and minimising the use of
water for different paper grades
–Efficient separation of cooling waters from process
water.
–The shower water system is usually the biggest
consumer of fresh water: most of the fresh water
must be replaced by clarified white water.
–Recycling part of the vacuum pump sealing water.
–Design and maintenance of piping and storage
chests.
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Techniques to consider in the
determination of BAT
3) Reduction of fibre and filler losses
–Tuning of the pulp refining and screening just
ahead of the feed to the paper machine to
maintain proper balance of different types of
fibres in pulp.
–Efficient control of paper machine headbox
–Sufficient use of paper chemicals to reach
improved fibre retention in order to get a good
paper web formation.
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Techniques to consider in the
determination of BAT
4) Recovery and recycling of coating colourcontaining effluent
–The pigments are expensive, so the recovery of
a part of the coating colour for reapplication and
minimisation is cost-effective
–One method is ultra-filtration: water and
chemicals are separated from each other by
using a semi-permeable membrane.
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Techniques to consider in the
determination of BAT
5) Energy savings through energy efficient
technologies
•There are opportunities for energy saving in
many stages of the process.
•Example: Energy savings through heat recovery
systems
–The purpose: to lower the mill' s consumption
of primary energy by using waste energy from
the process
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Techniques to consider in the
determination of BAT
6) Measures for noise reduction
– For internal noise sources:
• Installations of a new closed hood with higher
sound insulation
– For external noise control:
• Installation of absorptive silencers
• Installation of pipe resonators to reduce noise
levels from exhaust air fans and vacuum pumps,
• Silencers and sound insulation hoods for the fans
on the building roof.
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Techniques to consider in the
determination of BAT
7) Others techniques are:
• Control of potential disadvantage of closing up the water systems
• Separate Pre-treatment of Coating Wastewaters
• Measures to reduce the frequency and effects of accidental discharges
• Measurement and automation
• Installation of an equalisation basin and primary treatment of wastewater
• Secondary or Biological Treatment - Aerobic Methods
• Chemical precipitation of wastewater from paper mills
• Substitution of potentially harmful substances by use of less harmful
alternatives
• Pre-treatment of sludge (de-watering) before final disposal or incineration
• Options for waste treatment.
• Installation of low NOx technology in auxiliary boilers (oil, gas, coal)
•Use of combined heat and power generation
•Optimisation of de-watering in the press section of the paper machine
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
BAT: Best Available Techniques
• General measures:
1.Training, education and motivation of staff and
operators.
2.Process control optimisation.
3.Sufficient maintenance has to be ensured.
4.Environmental management system which
clearly defines the responsibilities for
environmentally relevant aspects.
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
BAT: Best Available Techniques
• Measures for reducing emissions to water:
1.Minimising water usage for different paper
grades by increased recycling of process waters.
2.Control of potential disadvantages of closing up
the water systems.
3.Construction of a balanced white water, filtrate
and broke storage system and use of
constructions, design and machinery with reduced
water consumption when practicable.
4.Measures to reduce frequency and effects of
accidental discharge.
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
BAT: Best Available Techniques
• Measures for reducing emissions to water:
5.Collection and reuse of clean cooling and sealing
waters or separate discharge.
6.Separate pre-treatment of coating wastewaters.
7.Substitution of potentially harmful substances by
use of less harmful alternatives.
8.Effluent treatment of wastewater by installation
of an equalisation basin and primary treatment.
9.Secondary or biological treatment of wastewater
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
BAT: Best Available Techniques
• Measures for reducing emissions to air:
1.Installation of low NOx technology in auxiliary
boilers.
2.Reducing SO2 emissions from steam boilers by
using low sulphur oil and coal or controlling S
emissions.
3.Use of combined heat and power generation.
4.Using renewable sources like wood or wood waste
to reduce the emissions of fossil CO2 (only applicable
if papermaking is integrated with virgin pulp
production).
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
BAT: Best Available Techniques
• Noise attenuation:
–BAT is the reduction of noise levels audible in
the vicinity of paper mills.
–The measures applied will depend to a large
extent on the specific noise problem of a mill
and the targets set.
–Usually they will be much stricter when the mill
is located adjacent to a residential area.
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
BAT: Best Available Techniques
• Chemical usage:
1.Ensure the availability of a database for all
used chemicals and additives .
2.Application of the principle of substitution: less
hazardous products are used when available.
3.Measures to avoid accidental discharges to soil
and water from handling and storage of
chemicals.
4.Design and operation of facilities in such a way
that dangerous substances cannot escape.
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Emerging Techniques
• Some “promising techniques” are addressed
that can not (yet) be considered BAT due to the
stage of development of these techniques.
• The paper mill of the future can be probably
described by the following characteristics:
–Decrease in paper mill water consumption and specific
emissions by means of increasing water re-use, closed
water loops and internal water treatment
–Increase in electricity consumption (specific to
production)
–Decrease in paper mill noise level
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Emerging Techniques
• Minimum effluent paper mills - optimised
design of water loops and advanced
wastewater treatment technologies.
• Impulse technology for dewatering of
paper.
• Condebelt ® process.
• Internal heat pumps.
• Total site integration tools.
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Emerging Techniques
• Minimum effluent paper mills - optimised
design of water loops
– To apply a combination of membrane filtration,
ozonation and evaparation
–Can reduce fresh water consumption
– Are only applied in pilot-scale.
– Full scale expierences are limited to a few
examples in the world
– There are still operation problems and
relatively high costs
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Emerging Techniques
• Impulse technology for dewatering of
paper
– Dryness levels of 55-65% before the drying
section (15-25 % more than ordinary press
section)
– Decrease the heat consumption
– The development work is still at an early stage.
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Emerging Techniques
• Condebelt ® process
–The Condebelt ® drying process is a new way to dry
paper and board.
–The paper web coming from the press section is
dried between two steel belts instead of traditional
steam cylinders.
– In 1999 there was two Condebelt ® drying
processes in commercial operation
– More square meters from the same amount of
fibres can be manufactured without loosing
product quality
– Higher potential for energy recovery
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Emerging Techniques
• Internal heat pumps
– Are used for pumping heat from one medium
(air) to another (for example water)
– Investment costs are quite high
Introducción
Introduction
Classification
Process
Consumption
Techniques
BAT
Emerging
Departamento de
INGENIERÍA QUÍMICA y
TECNOLOGÍA
del MEDIO AMBIENTE
Emerging Techniques
• Total site integration tools
– Try to combine the whole energy, water, fibre,
chemicals, system to create a good integration of
the mill
– Lower emissions to air and water and at the
same time to reduce the formation of solid
waste and energy
– The total site integration tool software is not a
big investment.
Thank you for your attention!