Michael Jansen
Processing of plastic packaging waste
1st International EIMPack Congress
Lisbon, 29th – 30th November 2012
Processing of plastic packaging waste – from
material following the DKR specifications to
milled goods
Dipl.-Ing. Michael Jansen
Michael Jansen
Processing of plastic packaging waste
• Introduction
• Methodology
• Results
• Conclusion
Table of content
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Michael Jansen
Processing of plastic packaging waste
• Article 11(2a) of Directive 2008/98/EC of the European Parliament
sets a recycling quota for plastic packaging waste (PPW) of 50 % by
2020
• Recent developments in several member states allow for alternative
collection schemes to source separation
– For example in Spain, France, Austria and the Netherlands
• The calculation of the quota is based on the input of certified
recyclers (Certification now on EU-level with EuCertPlast)
Legal basis
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Michael Jansen
Processing of plastic packaging waste
The PPW recycling chain
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Consumer
Source separated PPW
Sorting plant
MBT plant
MSRW
Sorting plant
PPW preconcentrate
Reprocessing plant Reprocessing plant
Polymer concentrate(HDPE, PP, PET, film, mix)
Polymer concentrate(HDPE, PP, PO, PET, film, mix)
Polymer concentrate(PO, film)
Plastic granulate Plastic granulate
• Studies regarding the source
of the plastic packaging
waste, success of the source
separation and potential in the
MSW
• Studies regarding recovery in
MBT plant
• Efficiency of sorting plants
issue of past publications
• Reprocessing has not been
described so far
Michael Jansen
Processing of plastic packaging waste
Development of recycling process
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• Production of granulates often
includes addition of additives
to influence properties
• Process was split into two
parts
– Mechanical re-processing is
subject of studies of the
RWTH Aachen
– Polymer technological re-
processing is subject of
studies of the TU Eindhoven
• Due to certain requirements to
the milled good process
stages were set
Mechanical re-processing
Polymer technological re-
processing
Milled good
Plastic granulate
Polymer concentrate
Re-processing plant
Michael Jansen
Processing of plastic packaging waste
• The milled good needs to be clean, i.e. no surface adhering
contaminants (mechanical properties, odour)
• Certain polymers have to be removed (e.g. PVC during PET
recycling; certain combinations are allowed e.g. HDPE + PP)
• The milled good needs to be dry (foaming during remelting due to
evaporation of water)
• Paper, metals, stones, etc. have to be removed to prevent high wear
rates, blocking or breakage of machines
• Energy consumption should be as low as possible
• Yield should be as high as possible
Comminution, Screening, Washing, Density media separation, Drying
(centrifugal, thermal)
Requirements to the mechanical process
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Michael Jansen
Processing of plastic packaging waste
• Obtain a mass balance
– Recovery of mass
– Yield of recyclable material
• Measure energy consumption
of each stage
• Measure water use and
estimate treatment costs
• Compare source separated
and recovered samples, i.e.
work with real waste samples
instead of artificially
generated ones
Goals of the experiments
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Recovery: 20 % Yield: 93 %
Michael Jansen
Processing of plastic packaging waste
• The potential in the input is
difficult to measure (multi-
material packaging, e.g. PET-
bottle with PE-lid and PP-
label)
• The losses in the process
stages are difficult to measure
due to particle size and colour
Issue
• Screening was believed to
have the largest impact on the
yield
• Other losses of recyclable
material were assumed to be
negligible
• The sink-float-split observed
during density media
separation was transferred to
screening
• Other methods were checked
but were found to be less
precise
Workaround
How to calculate the yield?
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Michael Jansen
Processing of plastic packaging waste
Origin of sample material and DKR-no.
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Sample
number
Source PE 329 PP 324 PO 321 PET Film
310
Mixed
plastics
350 MSRW Source
separation
system
1 x x x x 328-3 x
2 x x x 325 x x
3.1 x x x 328-1 x x
3.2 x x x 328-1 x x
4.1 x x x
4.2 x x x
5 x x x 328-2 x x
n = 22
Screening vs. No screening
Hot washing vs. Cold washing
Michael Jansen
Processing of plastic packaging waste
Mass balances HDPE samples
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0,0%
10,0%
20,0%
30,0%
40,0%
50,0%
60,0%
70,0%
80,0%
90,0%
100,0%
1 2 3.1 3.2 5
Sh
are
of
pro
du
cts
fro
m t
ota
l m
ass
Sample number
Soluble substances [%]
Water [%]
Filter residues [%]
Sink product [%]
Float product [%]
Screen loss [%]
Recovery of mass [%]
Yield of recyclable material [%]
Michael Jansen
Processing of plastic packaging waste
Screening
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• Screening is able to reduce
the amount of dirt in the
intermediate product
• High losses of plastic with a 8
mm screen deck
Screening is suggested but
with finer screen deck
0%
5%
10%
15%
20%
25%
30%
35%
40%
Screen loss [%]
Sh
are
of
inp
ut
< 8
mm
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Fine - Plastic Fine - Water Fine - Dirt Coarse -Plastic
Coarse -Water
Coarse - Dirt
Sh
are
of
pla
sti
c/w
ate
r/d
irt
fro
m
fin
e/c
oars
e m
ate
rial
Michael Jansen
Processing of plastic packaging waste
Recovery and yield
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• Around 75 % of the input got
recovered
• Around 90 % of the recyclable
material yielded into the
product
• Recovered samples are dirtier
• Therefore lower recovery but
the same yield
0%
5%
10%
15%
20%
25%
Water and dirt [%] (sourceseparated)
Water and dirt [%](recovered from MSRW)
Sh
are
of
wate
r an
d d
irt
fro
m t
he
inp
ut
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Recovery of mass [%] Yield of recyclable material[%]
Sh
are
of
mass r
eco
vere
d i
nto
th
e p
rod
uct
Sh
are
of
recycla
ble
mate
rial
yie
lded
in
to
the p
rod
uct
Michael Jansen
Processing of plastic packaging waste
Energy use HDPE samples
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• Main consumers are the
shredder, the hot washing
stage and the thermal drying
stage
• Heat loss is strongly
influenced by the calculation
model for wash water
management
• 18 kWh/Mg were used to
remove 1 % of moisture from
the product
• Drying equipment in the lab
different to industrial
equipment
5
15
25
35
45
Drying efficiency[kWh/(t*%)]
En
erg
y u
se [
kW
h/t
]
-
50
100
150
200
250
300
350
En
erg
y u
se [
kW
h/t
]
Michael Jansen
Processing of plastic packaging waste
Total energy use
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0
500
1000
1500
2000
2500
3000
3500
4000
4500
Energy per ton of input [kWh/t] Energy per ton of product[kWh/t]
En
erg
y u
se [
kW
h/t
]
60%
70%
80%
90%
100%
Fraction of heat from totalEnergy consumption [%]
• Around 500 kWh/Mg energy
investment for processing
• 90 % of the energy provided
has to be heat
• Huge variations between
different polymers (e.g. LDPE
>> HDPE)
• Potential for optimisation due
to process design and
equipment selection
Michael Jansen
Processing of plastic packaging waste
• For the first time re-processing of PPW was studied under
consideration of recovery, yield, energy use, water use and waste
water quality
• It was proven that recovered and source separated PPW can be
treated (and in a similar manner)
• Recovery of around 75 % is possible (recovered PPW is app. 7 %
dirtier)
• Yield potentially as high as 90 % (no matter of the origin of material)
• Around 500 kWh/Mg have to be invested (mainly for shredding, hot
washing and drying)
Conclusions
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Michael Jansen
Processing of plastic packaging waste
Any Questions?
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Thank you for
your attention!
Dipl.-Ing. Michael Jansen
Department of Processing and Recycling (I.A.R.)
RWTH Aachen University
Wüllnerstraße 2
D-52062 Aachen
www.iar.rwth-aachen.de