‘Аbsorbing the Potential of Wood Waste in EU
Regions and Industrial Bio-based Ecosystems —
BioReg’
D2.4: RECOMMENDATIONS FOR INDUSTRY
STAKEHOLDERS
To the attention of the Research Executive Agency
Organization
EUBIA
Due date
31.08.2017
This project has received funding from the European Union’s H2020 research and innovation programme
under grant agreement no 727958
Document information
Nature of the deliverable
Dissemination Level
the Commission Services)
Document Approval
Document Review
Date
Version
Reviewers
29.06.2018
1
Ana Luisa FERNANDO
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ACKNOWLEDGEMENT
This report forms part of the deliverables from the project "BioReg" which has received funding from the European
Union’s Horizon 2020 research and innovation programme under grant agreement n° 727958. The Community is
not responsible for any use that might be made of the content of this publication.
BioReg project proposes to create a platform of stakeholders who are able to influence and develop their regions
towards bio-based industries and products.
The project runs from January 2017 to December 2019, it involves 8 partners and is coordinated by “le C BINET
D'ETUDES SUR LES DECHETS ET L'ENERGIE” (CEDEN).
More information on the project can be found at http://bioreg.eu/project/.
ABSTRACT
On the basis of the conclusions of WP1 and tasks 2.1 and 2.2 in WP2 as well asand the feedback from visits of some
waste centers, the current document aims at bringing out relevant lessons regarding technical aspects in order to
share them with industrials.
Recommendations proposed in the current deliverable are intended to industrials from the regions of Normandie
(France), Alentejo (Portugal) and Lubelskie (Poland) and available at the BioReg Platform. Yet, the lessons and
recommendations highlighted can be useful to any European region, especially Eastern European countries.
EXECUTIVE SUMMARY
Wood waste demand is increasing (recycling and energy) and industrials must anticipate this evolution by adapting
equipment and designing preparation chains enable to meet requirements of end users. This document provides a
series of practical information, recommendations, and examples for industry stakeholders about grading, sorting,
handling, and processing of waste wood. While in the past the most of wood waste was disposed of into landfills,
or reused and recycled locally, nowadays increasing volumes of wood waste are traded at both domestic and
international level. The two main end uses for waste wood are recycling for the panel board industry and energy.
Careful sorting and handling of different materials is essential to ensure the compliance with the quality
requirements of the different end uses. Along the value chain, recommendations address wood waste preparation,
but not collecting (upstream) and outlets (downstream), and classification. The recommendations include the
following technical aspects:
-
Classification,
-
Mode of preparation depending of requirements of the end user,
-
Equipment,
-
Dust, etc.
The recommendations are rather general because the techniques, technologies but especially the strategies of
preparation (combinations, equipment complementary or adapted to the waste of wood, mode of grinding and
screening, adjustments of the equipment of optical sorting) evolve constantly and fall under the industrial secret.
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CONTENTS
1
Context
5
2
Classification of wood waste
7
3
Quality requirements for recycling and for energy use
10
4
waste wood sorting and treatment platforms
11
5
Mixed Waste collection centers
13
6
Case study: Veolia Seine Multirecycling Centre
14
7
Conclusion
17
8
References
18
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1
CONTEXT
According to a 2015 EU parliament Briefing1 the European amount of wood waste produced in 2012 was
52.9 Mt. These volumes were disposed of by land-filling (37%), burning with energy recovery (30%) and
particleboard manufacture
(30%). Energy and particleboard manufacturing are two competing
industries, but their requirements can be different: the energy sector requires a material with low metal
content, low chlorine and low contaminants, in order to ensure a sustainable energy generation with
reduced atmospheric emission. The panel industry is interested more in the physical quality of wood
waste, preferring solid wood in its supplies. Solid wood comes mainly from buildings (construction and
demolition) and contains more pollutants than the waste wood from furniture (mainly reconstituted
wood). Therefore, the separation between recycling and energy is not so clear. Often the operators on
the sorting platforms dilute their waste wood with clean wood like pallets (or low treated wood like
waste wood coming from household) in order to achieve requirements for the panel industry.
Figure 1. Use of waste wood by source in Europe. (Source: WBPI)
While a decade ago most wood waste was reused
and recycled locally, today significant volumes are
shipped across Europe. Wood waste trade
predominantly occurs in Western Europe, in
countries with established wood recycling sectors
and relevant consumer base
- be it the panel
industry, energy sector, or other users. Most
European countries have particleboard
(or
chipboard) production facilities. However, not every
producer is using wood waste, due to insufficient
availability of locally affordable virgin wood, low
quality of the waste wood feedstock for high-quality panel manufacture, or long transportation distance.
Nowadays, the use of recycled wood in panel has become a sales argument (“plus product” given to the
environmental asset) and in France for example, a tax could be applied when panel don’t contain
enough recycled wood in their composition (eco modulation/eco participation). This tax could incite the
panel industry to increase the rate of recycled wood in their panel.
There is often a competition for feedstock between the biomass energy industry and the particleboard
manufacturing industry although the quality requirements can be different:
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Table 1.
Wood waste consumption in particleboard production. (Source: WBPI)
The energy sector requires a material with no metal content, low chlorine, and low contamination, in
order to ensure a sustainable energy generation with low atmospheric emission. The panel industry
requires a material with low contaminants and at the same time with high physical quality, especially for
solid wood.
Figure 2. Wood waste stream in Europe for energy (to the left) and panel industry
(to the right). (Source: WBPI - POYRY)
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Recommendations
Good waste management principles require waste hierarchy to be followed: materials are
first re-used and recycled into new products, before energy recovery and disposal. This
principle should also apply to waste wood.
Cascading use principle should be applied whenever national/local conditions allow (ex: if
there is no panel industry locally, better to recover in energy in order to avoid long
transportations)
Know your market: the energy sector and the particle board sectors require different
qualities of recycled waste wood: this affects the production process or waste wood.
Efficient and effective collection and pre-treatment are essential steps to ensure local
availability of sufficient quantities of high-quality waste wood and for stable end use
markets.
Germany and France are the leading producers of particleboard in Western Europe (Tab.1), and both
have a good supply of virgin wood. Both countries have experienced increasing prices for all wood feed
stocks, driven by increasing competition from bioenergy during the last decade. Yet there is still no
significant shift towards the use of wood waste in particleboard production due to concerns over panel
quality. France has become the key supplier of wood waste for panel production in neighbouring
Belgium and Italy (Fig.2), while domestically the share of wood waste used in the raw material mix
remains low.
2
CLASSIFICATION OF WOOD WASTE
Wood waste comes mainly from the wood industry, construction and demolition, and packaging.
Depending on its quality grade, wood waste can be recycled (e.g. as panels or mulching), incinerated
with energy recovery, or treated at special facilities for disposal. Therefore, sorting and segregating
wood waste according to different quality classes is very important. The European Waste Catalogue
introduced by the Waste Framework Directive is a common tool that can be used to classify waste
wood. However, there can be differences in the grading systems adopted by Member States and some
countries have specific regulations and classifications of the wood waste that take in account their
quality and destinations. All national classification systems include at least two categories of waste
wood:
1) clean wood (based on different approaches depending on the country, in terms of definition or
limit values of contaminants);
2) hazardous waste which includes creosoted, impregnated wood waste with metal salts. The
definition of impregnated wood remains subject to interpretation, since 2004some types of
impregnated wood, especially for private households, no longer contain arsenic or creosote, but
may still contain copper and organo-halogen complexes.
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Table 2. Limit values for Class B waste wood in France
In many cases the national classifications include
also one or two intermediate categories, with
fairly similar criteria:
Class "B" or "2" includes wood waste
0,2
which does not contain heavy metals in
4
higher percentage than virgin wood and
does not contain any organo-halogenated
5
or preservative agents.
30
For example, in France, the threshold to
30
respect in order to be in class B are shown
in table 2:
50
Class "C" or "3" includes treated wood
200
with preservatives and contains metals in
900
higher proportion than virgin wood, and
organo-halogens.
3
In some countries, the National classification
2
system is not available, while some other
countries such as France are in the process of setting it up. Table 3 shows the current scheme proposed
for the French classification of waste wood. The scheme proposes four categories of wood waste, which
match the categories adopted by the British and the German systems:
Table 3. Proposed scheme for classification of waste wood in France.
Class B or 2 is in general assimilated to biomass according to the directive IED of 2010. But it is necessary
to prove that the resource respect some threshold (which match in fact with the composition of virgin
wood): hence analyses are required like in France for example: cf. table 2 - Maximum content of metals
for class B waste wood in France).
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At European level, all Member States have transposed the EU Waste Framework Directive (Dir. 98/2008
EC) into their national legislations; the directive set a list of wastes classified by specific codes, which
include also some types of wood wastes, as shown in table 4.
Recommendations
Different categories of waste wood can be utilized to different end uses. Clean wood can be
recycled or converted into energy, contaminated wood can be sometimes used for energy or
disposed of into landfills, hazardous waste must be landfilled.
For a processor of waste wood, it is vital to be capable of sorting products into different
classes in compliance with the classification system in place in its country, as this determines the
end use that waste wood can have.
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3
QUALITY REQUIREMENTS FOR RECYCLING AND FOR ENERGY USE
Depending on the ways of valorization of wood waste, there can be different quality requirements for
the feedstock. Nevertheless, there are many common parameters for the different end uses, in
particular for the content of heavy metals, chlorine and other contaminants.
For the panel industry, the EPF (European Panel
Federation) has sets maximum levels of
contaminants in the wood waste used in the
composition of panels as well as in the finished
products.
25
The EPF standard also sets maximum levels of
50
undesirable elements (2%) and moisture (20%),
however, in some countries, National regulations
25
can set more binding thresholds
(ex. in
40
Germany).
90
The pulp and paper industry can also be an
25
additional recycling route for waste wood; in this
(F)
100
case the feedstock must be of very high quality.
The main requirements are indicated in table 6.
1000
5
Regarding
the energy
use of
waste
wood regulations differ across Member States
0.5
and depending on the type of installation. In
general, waste wood is not considered as solid
ry
biofuel, such as woodchips or wood pellets.
Therefore, the quality criteria regulating the use
of waste wood for energy are related to the
European Waste Catalogue, which applies to
incineration
and co-incineration
plants.
Regarding the quality of wood waste, the
plastics)
thresholds and parameters used to qualify clean
wood are not the same from one country to
another. For incineration, there are no
thresholds for incoming wood waste.
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4
WOOD WASTE SORTING AND TREATMENT PLATFORMS
Processing of wood waste has two main objectives: one is to obtain a suitable granulometry for the end
use and the second is to improve the final quality of the product in relation to the requirements of the
end use. In large facilities for particle board manufacturing or for energy production, sorting occurs
directly at the plant, upstream of the production or energy conversion plants and often at outdoor
platforms. At these platforms, wood waste is handled, shredded, and screened.
Handling
Handling of bulk and heterogeneous material
at sorting sites can be done with shovels
equipped with a grapple or with bucket
loaders
(left). Bucket loaders feed the
shredders and the screens, manipulate
material
(fine fraction, shredded material)
and load trucks for evacuation.
Shredding
The aim of grinding and shredding is to
reduce the particle size of incoming wood
waste and to facilitate the removal of iron.
Grinding is often performed in two steps: a
slow grinding first, in order to avoid
breakage and to facilitate the recovery of
metal contaminants, followed by rapid
grinding
to
obtain
the
desired
granulometry. The shredders are generally
equipped with one or more magnetic
rollers enabling the removal of ferrous
contaminants.
The two shredders are arranged in series
with conveyor belts which convey the
material from the slow shredder towards
the fast shredder. The rapid shredder is
generally equipped with a grid to calibrate
the final product. The meshes are often as
wide as 250 mm for wood waste but can be
also of smaller size
(up to
80mm). The
smaller the mesh, the more "fine fraction"
is produced and the more metals are
recovered.
This project has received funding from the European Union’s H2020 research and innovation programme
under grant agreement no 727958
Screening
Depending on the requirements of the end user, the shredded material can be recovered directly, or
submitted to screening, by which fine particles are removed and the output material is more
homogeneous in size. This can be done with
simple drum screens, which separate the
incoming material into a fine fraction and a
coarser fraction. The meshes are round or
square and in general between 10 and 30
mm.
Adjusting the feed rate and drum rotation
will influences the amount of fine fraction
obtained.
Recommendations
Different processing steps are necessary to obtain a suitable granulometry and to improve
the quality of waste wood in relation to the requirements of the end use.
Different equipment is available for handling, shredding and screening of waste wood.
Accurate design of the process is necessary to minimize costs and maximize productivity.
Screening (extraction of fine particle > 8-20 mm) improves the quality of products, even
though this step entrails the generation of 20 % of by-products (fine fraction), more polluted
and very difficult to valorise.
One or two-stages shredding? One stage of shredding is less expensive, is sufficient and
avoids reducing the size of the products too much. It is sufficient to prepare products for
energy use with a granulometry> 200 mm. Two-stage shredding generates smaller particles
and improves the efficiency of removal of ferrous and non-ferrous contaminants from the
feedstock.
Separation of two types of wood on platforms before preparation for energy (reconstituted
wood) and for panel industry (solid wood). This strategy is interesting to achieve the different
requirements of industry and energy. Solid wood comes mainly from building and is more
polluted than reconstituted wood: hence, the mobilization of solid wood can increase the
amount of heavy metal or organo-halogen compounds.
Set up of electric stationary equipments instead of mobile ones. This solution enables to
save money during operation (low energy consumption) and has a very low impact on
environment. Stationary equipment reduce dust emissions thanks to aspiration systems and
confining.
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5
MIXED WASTE COLLECTION CENTERS
In some cases, sorting can be performed at
dedicated mixed waste collection centres
usually held indoor, where mixed waste is
collected and then separated into different
groups depending on its quality and its final
use. At these facilities, sorting can be either
manual, mechanized, or also assisted by
optical devices. Collection and sorting centres
usually perform a pre-sorting of wood waste
by means of a grapple or a clamp mounted-up
on a shovel. The pre-sorted waste is then introduced into a hopper feeding a separation chain which
separates different materials: wood, heavy inert, cardboard, plastics. Optical sorting and manual sorting
make it possible to separate different categories of wood (based mainly on the colour). Conveyor belts
allow different materials to flow from one piece of equipment to another. The mechanised sorting
centres for mixed waste contain generally optical sorting equipment to separate the wood fraction from
other types of waste. Two main techniques are to detect contaminants in wood and to separate
different types of wood waste: Near Infrared spectroscopy and XRF (X-ray fluorescence). The optical
sorting makes it possible to improve the quality of the resource, to respond as closely as possible to the
requirements of the various users. Tests showed that NIR optical sorting can separate clean wood when
it is mixed with glued wood waste (panel residues) and coated wood waste. For XRF, tests have shown
that the technology can detect even wood inorganic preservative treatments (copper and chromium).
Wood waste dust is made of very fines particles
which are harmful for human health. Dust is
generated all along the preparation chain and in
particular while shredding and truck loading.
Authorities are more and more demanding on
this concern. Different types of solutions and
actions can be implemented to address this
issue, and they are mainly based on the
execution of those processes in confined
environment equipped with dust aspiration
system.
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6
CASE STUDY: VEOLIA SEINE MULTIRECYCLING CENTRE
The Seine multi-recycling centre in Oissel (France), is a
high-performance sorting centre owned and operated
by Veolia. Started in 2013, it employs 28 people and
covers an area of 41,600 m2. The centre treats 76.000
tons of mixed waste every year, 20.000 tons of which
is
represented by recycled wood
(furniture,
demolition, and construction etc.) The sorting centre is
adjacent to an outdoor wood waste treatment
platform which performs a first selection of wood
waste for energy use, disposal, and recycling. The
wood waste that can be recycled is transported from
the platform to the sorting centre, for separation from
inerts and contaminants. At the centre, the waste
material undergoes the following processes:
1) Reception: the waste is initially received in a dedicated area where a first selection with a loader
is performed;
2) Mechanical separation: the waste is separated mechanically by using a disposer, a mechanical
sieve and an aerolitic separator;
3) Selection of recyclable material: the material which can be recycled is screened through an
additional sieve then is processed by optical sorting machine, followed by an overband and
finally separated with Eddy current.
4) Quality control and storage: at the end of the separation chain, the quality of the recycled
material is checked by cabin operators and automatically stored in silos.
The center provides differents categories of prepared wood waste, to panel production industrials
(Belgium) and to energy production plants (Belgium, Sweden, UK, France). The center has the specifity
of treating end of life furnitures.
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Recommendations
Process has to be designed depending of types of wastes received. The process for wood
waste alone will be less thorough than mix waste (wood with glass, plastic, ferrous, etc.).
However, the process has to anticipate evolution of types of waste.
Process has to be designed depending on outlets and has to make it possible to achieve the
demand and requirements of each of them (recycling, energy, cimentery, etc.), which are
systematically different.
The risks of fire must be taken into account in a very serious and rigorous way. Many fires
have occurred on this type of centres, due to the presence of dust, waste, plastics and
machinery in confined areas.
Dust must be collected via suitable ventilation equipment and pipe network, and stored. Dust
is harmful for human health. Dust can be valorized in cimentery or hazardous waste
impregnation. An endless screw enables to evacuate fine particles without generating dust.
Optical sorting is expensive and must be implemented if need be. Settings are complicated,
very sensitive and require specific recommendations for preparation (particle size, mix level,
etc.) in order to make the sorting as efficient as possible.
The capacity of these centres must be greater than 50 000 t/year to amortize heavy
investments.
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Figure 12. Veolia Seine multirecylcingcentre in Oissel. Reception area where the waste is selected with
loader (up left) and fed into a conveyor belt (up right); separation with aerolitic system (middle left)
and optical system (middle right); quality control (bottom left) and storage of non-recyclable waste
(bottom right). The recycled wood is stored in silos outdoor.
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7
CONCLUSION
The recommendations proposed in the current document mainly concern the wood waste preparation stage which
is crucial in the value chain. Wood waste preparation has been relatively straightforward so far but is changing
rapidly with increasing demand for wood waste. In fact, in order to valorize the resource, industrials have to
respond to the increasingly strong and different constraints according to buyers (thresholds in pollutants,
percentage of fine particles, size of the grinds more or less large, absence of MDF, etc.). To stand out, they develop
preparation strategies and techniques to maintain a competitive edge. Thus, for some years, the preparation lines
are more and more complex and include increasingly sophisticated equipment (optical sorting, aeraulic sorting,
screen "3 fractions", flip flop screen, suitable mixtures, dust collection, etc.).
The current deliverable presents recommendations to industrialists which may be of a rather general nature for
industrials who already have extensive knowledge in this field, but may be particularly useful to waste
professionals who plan to treat this type of waste, or those in certain regions (recipient regions of Bioreg or
Eastern European regions) where there is not yet the knowledge already acquired in the so-called model regions.
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8
REFERENCES
BOULDAY D., VARGAS A. 2017 - BioReg State of the Art Technical Report
VV.AA. 2012 - PAS 111-2012 Specifications for The Requirements and Test Methods for Processing Waste Wood.
British Standard Institution and Wood Recyclers Association UK
A. BROMHEAD - The Wood Recycling Industry Code of Practice. Wood Recyclers Association UK
M.HOLDER, 2016 - Heating Up. Wood Recycling Magazine Spring/Summer 2016
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