15th European Roundtable on Sustainable Consumption and Production
(15th ERSCP)
2012, May 2 – 4, Bregenz, Austria
End of Life and Waste Management of Bio-based Products and
Composites
Gernot Kreindl
Montanuniversitaet Leoben, Institute for Sustainable Waste Management and Technology (IAE)
Franz-Josef-Straße 18
8700 Leoben
Austria
[email protected]
Abstract
During recent years a new group of packaging materials has been introduced to the market.
Biopolymers for short-life applications are already commercially available. Eco-friendly materials
especially for food grade packaging as well as service packaging for retail are going to replace pure
fossil-based foils and bottles gradually. The Input of biopolymers in existing municipal waste
management systems raises a series of questions dealing with recycling or disposal strategies. The
differentiation between biological origin and biodegradability is important. Waste material
classification and the development of an effective collection system for preventing littering problems
is a big issue in today’s waste strategies. For this reason several end-of-life options for biopolymer
lightweight packaging coexist. All these treatment strategies have their pros and cons and require an
efficient and standardized waste collection system. This paper should point out different waste
management strategies for biopolymer packaging and their impacts on the Austrian waste
management infrastructure.
Note
Because my Thesis has not been approbated yet, I cannot go into detail too much. Apart from that I
will give a comprehensive presentation about biopolymer packaging and the resulting end of life
issues at the next ISWA World Congress 2012 in Florence (www.iswa2012.org).
Keywords: Austria, waste management, biopolymers, separate collection, composting, incineration;
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Gernot Kreindl, End of Life and Waste Management of Bio-based Products and Composites
Introduction
The amounts of biopolymers for packaging applications are currently increasing. There is a shift
towards sustainability and substitution of fossil-based raw materials by renewable resources. Crude
oil, natural gas as well as coal are endless resources. Today, driven by EU environmental legislation,
the decrease in the dependence of fossil-based materials is a present but also future focus of
individual EU Member States. Biopolymers can support a sustainable development. Not only the
production (energy and raw material consumption), but also the phase of use and recycling as well as
disposal approaches should be considered. This includes the entire life cycle. The focus of this paper
is equal to the topic of my PhD-Thesis and is dealing about the end of life-scenarios of biopolymer
(packaging) waste in modern waste management systems. Therefore, the impacts of existing
collection, transportation, treatment - and disposal methods on the fate of biopolymers are
investigated. Currently the amount of bioplastics in different plastic-rich waste streams is difficult to
determine. It is clear that to date the emergence and the market penetration of biopolymer packaging
is negligible compared to other waste materials. The ongoing trend, especially in the field of
packaging, is towards lager use of bioplastics. Market volumes and the development of production
quantities are part of this paper.
Terminology
The terminology in the context of bioplastics is complex and for outsiders often confusing.
Biopolymers are in general divided in three groups, based on their source: renewable resources,
petrochemical raw materials and mixtures of renewable and fossil resources (blends). The term
“bioplastic” does not necessarily say something about the biodegradability of the material. There are
biopolymers as well as conventional petro-based polymers which are biodegradable. That means that
under specific conditions decomposition to CO2, water and residual biomass takes place. Figure 1
gives a classification of various types of polymers. The biodegradability sets the focus here.
Figure 1: Classifications of (bio-)polymers
Besides the broad classification of different polymers, there are some terms describing the properties
of bioplastics to be considered. Table 1 lists important definitions relating to biopolymers.
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Table 1: Definitions
Term
Description
bio-based
material partly or completely derived from biomass
renewable raw material
after the end of life returning to the natural cycle
bio-composite material
composites with a regenerative, renewable material content
biomass, bio-based carbon content
material of biological (renewable) origin composed of
biogenic carbon (14C-radiocarbon dating)
biodegradation
biological activity driven by enzymatic reactions forces
significant change in the material structure
biodegradability
sum of all (natural) anaerobic and aerobic decompositions
processes
compostability
ability of complete biodegradation
Standards
Most of the definitions listed in Table 1 are copied from standards. Today a lot of different European
(German, Austria) and International (US, Australia) Standards exist for bioplastics. They are mainly
dealing with natural degradation under specific environmental conditions, particularly for packaging
waste. The following review highlights some standards.
 DIN V54900:1997 - Examination of Biodegradability of Plastics
This German standard DIN V54900 (1-5) is rather old (1997) and has been replaced by European
Standard DIN EN 13432.
 EN 13432:2000 - Requirements for Packaging Recoverable Through Composting and
Biodegradation – Test Scheme and Evaluation Criteria for the Final Acceptance of
Packaging
The standard is specially adapted to the biological utilization of packaging materials. It contains
testing schemes and evaluation criteria for packaging and has totally replaced DIN V54900. EN
13432 contains requirements for material characterization, a description of the biological
decomposition as well as the influence of biodegradable polymers on compost qualities.
 EN 14995:2006 - Plastics – Evaluation of Compostability – Test Scheme and Specifications
This standard is not only for packaging material, but also for various kinds of plastic products.
The topics of EN 14995 are quite diverse, in terms of chemical characterization, biological
degradability, disintegration and ecotoxicity.
 ISO 17088:2008 - Specifications for Compostable Plastics
The standard has implemented the same testing scheme as Standard EN 13432 or ASTM D6400
and deals with the compostability of plastic products in general.
 ASTM D6400:2004 - Standard Specification for Compostable Plastics
The American Standard covers specifications for compostable polymers and derived products. In
addition to some definitions describing biopolymers, requirements are set for the complete
disintegration of the polymer material.
 ASTM D6868:2011 - Standard Specification for Labeling of End Items that Incorporate
Plastics and Polymers as Coatings or Additives with Paper and Other Substrates Designed
to be Aerobically Composted in Municipal or Industrial Facilities
This American Standard covers biodegradable polymers and products (including packaging) in
which plastic films are combined with carrier materials. This is made by lamination or by
Gernot Kreindl, End of Life and Waste Management of Bio-based Products and Composites
extrusion coating directly onto the paper. Thus, the entire product or the foil is composted in
industrial composting plants.
 AS 4736:2006 - Biodegradable Plastics – Biodegradable Plastics Suitable for Composting
and Other Microbial Treatment
The Australian Standard focuses on the biodegradable packaging and specifies methods for the
determination of biodegradability. There is a reference to Standard EN 13432.
Bioplastic market
All present standards are used to define and standardize testing schemes in context with composting
of polymer (packaging) materials. There is no binding rule that specifies the minimum content of
renewable raw materials in bioplastics. New approaches go towards the complete or partly
substitution of fossil-based raw materials by renewable resources. Today, blends are very common for
production of biopolymers. The new branch of the so called “green polymers” is based on advanced
manufacturing processes. Polymers, like Bio-PE, Bio PET, Bio-PA, etc. with a green image are used
for well-known applications, especially in the packaging industry. The next Figure 2 illustrates the use
of 46.4 Mio. t of plastics in Europe 2010. The packaging industry is the leading sector for the use of
plastics.
Figure 2: European plastics demand 2010 by segment [Source: PlasticsEurope, 2011]
For Austria, plastic consumption is shown in Table 2. Packaging has a market volume of about
429,000 t. A minor, but specific part consists of biopolymers. It is estimated that the total amount of
bioplastic packaging in Austria collected by the ARA-system is about 300 t/y. Reliable information on
the actual content of bioplastics in different plastic-rich waste streams does not exist so far. Currently
the biopolymer content is certainly less than 1 m-%. Most plastic packaging is collected separately by
household collection. The total amount collected in Austria is about 184,706 t of lightweight
packaging in 2011.
Table 2: Plastic consumption by sector [Source: Denkstatt, 2010; Kreindl, 2012]
Field of application
Market volume [t]
Packaging
429,000
Building & Construction
226,600
Automotive
82,500
Electrical & Electronic
61,600
Others
Total
300,000
1,100,000
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Today, 3-4 types of biopolymers are widely used for packaging. Polyhydroxyalkanoates (PHA)
derived from sugar beets are commonly used for food packaging and medical applications
(biodegradable implants in human bodies). In general, they are well biodegradable, printable and in
contrast to some other biopolymers they have better barrier properties against water vapor
permeability.
The feedstock for polylactic acid (PLA) is cornstarch. PLA is suitable for injection molded parts,
like everyday goods made out of plastic, office supplies, etc. A major application for PLA-material is
the beverage bottle production. The benefits of this material are the high elasticity coefficient, the
scratch resistance and the printability together with heat sealability as well as high transparency. A
good water vapor permeability of PLA leads to a limited scope in the field of packaging. Accordingly,
there are also some applications benefiting from this property (extension of the life period of fresh
fruit and bread). Coatings are currently the key to build up a kind of barrier layer to reduce
permeability.
Thermoplastic starch (TPS) and starch blends are made from native starch and used for loose fill
chips, catering products (disposable tableware) and various applications in the agricultural sector.
A classification by material groups in 2010 shows that there is an ongoing trend towards green
polymers. Production capacities of biodegradable starch blends as well as PLA are still growing.
Figure 3 is taken from a market analysis done by the European Bioplastics Association in cooperation
with the University of Applied Sciences in Hannover and is based on the production capacity by type.
Figure 3: Classification of biopolymers by materials groups 2010 [Source: European Bioplastics,
2011] Amounts are given in tonnes and %.
Looking at the end of life options for biopolymers, different recovery and disposal paths coexist. In
Austria as well as in other high developed European countries, no separate collection system for
biopolymers is established. Although production capacities of biopolymer packaging are increasing,
the current penetration of the market is still low. Impacts and effects cannot be measured at the
moment. However, for biopolymers a 2-digit growth per year (see Figure 4) is predicted. In 2010
about 724,500 t are produced – out of this nearly 60 % are non-biodegradable, but bio-based.
Gernot Kreindl, End of Life and Waste Management of Bio-based Products and Composites
Figure 4: Global production capacity of bioplastics [Source: European Bioplastics, 2011]
End of life options & labeling
In Austria, high developed separate collection systems for packaging waste exist. Littering of plastic
waste is a minor problem. The recycling rates are one of the highest in Europe. Waste management is
working properly. The different treatment options for biopolymers are shown in Figure 5. Depending
on the disposal behavior of consumers, after collection two treatment paths are possible: (feedstock)
recycling or thermal utilization.
Figure 5: Collection and treatment options for biopolymers in Austria [Source: Kreindl, 2012]
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Beside residual waste, the mixed plastic fraction from waste sorting can be supplied to waste
incineration. The resulting steam can be used in energy production as well as district heating. A part
of the plastic-rich fraction can also be used in solid recovered fuel (SRF) production. SRF replaces
primary fuels in cement plants. The share of renewable resources is crucial for the CO2 neutrality of
energy recovery. Apart from that, at present, the CO2 emission trading market for CO2-certificates has
reached a low level (approx. 7 €/t CO2).
Recycling in terms of feedstock recycling as well as cascade use of biopolymer packaging is also
possible. This approach requires separate collection systems (lightweight fraction). There are
approaches for non-biodegradable and even biodegradable plastics. The problem is, in addition to
minor amounts, a wide range of bioplastics with different material compositions exists on the market.
This means that some of the biopolymers are biodegradable, some of them are not. Furthermore,
blends with different renewable material content complicate recycling. For effective recycling and in
order to obtain revenues from it, pre-selected and pure bioplastic waste with high contents of
secondary raw materials is needed: the higher the purity, the better the recycling results. Today, the
recycling of biopolymers is at its beginning. Right now, the market penetration is not high enough to
make recycling of biopolymers profitable. Furthermore, modern recycling processes, which are state
of the art for commercial polymers, have to be adapted (process management, glass transition
temperature, etc.) to handle bioplastics properly. New bioplastic materials show their own behavior
during complex recycling processes. Keeping the decomposition as well as the depolymerization
within certain limits, are still a challenge. Currently, owners of recycling plants make an effort to
ensure, that no mixed PLA- and PET-fractions are getting into bottle to bottle recycling. This has to
do with different processing schemes.
Composting is also an option for biodegradable plastics. This should be considered after material
recycling and before thermal utilization. The production of humus-rich compost from different
organic waste is a kind of material use. Most of biodegradable polymers are only usable for industrial
composting. That has to meet certain standards. Non-biodegradable materials in addition to fossilbased polymers have a negative impact on the composting process. In recent years, some labeling for
(biodegradable) bioplastics was developed. Figure 6 shows different labels for compostable
biopolymers (in extracts). The labels presented below are some examples only and don’t necessarily
give information about the renewable material content.
Figure 6: “Seedling” (European bioplastics), compostability labels (Vinçotte)
Today, costumers are often overwhelmed by various types of labels. They are confronted with a lack
of information about the collection and possible treatment options for bioplastics. They often do not
know what do to with biopolymer packaging. Home composting rarely leads to success in terms of
complete decomposition in an adequate period of time. Owners of composting plants are not always
pleased with the development and introduction of biodegradable plastics either. Mixed plastic
fractions (petro-based and biogenic plastics) have a negative influence on the compost quality. There
are problems to visually allocate degradable from non-degradable plastics in biowaste. Sensor-based
near-infrared sorting is a key technology to detect and separate bioplastics in waste streams, but it is
connected to high investments. Therefore, plastics in general are contaminants and cause disturbances
during composting. They have to be separated before the composting process starts.
Near-infrared (NIR) sorting
High performance, sensor-based sorting technologies are state of the art in modern waste management
business. Today, a large variety of high speed sorting systems for plastic separation out of mixed
waste streams (yellow bin/bag) exists. The NIR-technology is based on the principle of transmission
Gernot Kreindl, End of Life and Waste Management of Bio-based Products and Composites
and reflection of radiation (light) in the range from 800 to 2,500 nm. At certain wavelengths, a variety
of materials show very specific reflection properties. The observed effect is that molecules begin to
vibrate and send out light at a specific wavelength. The part of the non-absorbed light spectrum can be
detected by sensors. The removal of detected materials is done by directed air pulses. By utilizing this
effect, it is possible to clearly determine different types of materials in real time. Similar to a material
specific fingerprint, the spectra, which are represented by the reflected light, are unique for each type
of material. [Kreindl, 2011] Figure 7 illustrates the fundamentals and technical features and gives an
overview of different NIR-spectra.
Figure 7: NIR material recognition (left) and NIR-spectra for different conventional types of polymers
(right) [Kreindl, 2011]
My PhD-Thesis is also about the recording of different NIR-spectra associated with biopolymers. As
you can see in the lower picture (see Figure 8) there is a clear difference in the NIR-spectra of various
types of PLA material. Sorting tests showed that the material detection of state of the art NIR-sensor
is able to distinguish between different types of plastics (bio- as well as petro-based polymers). This is
a necessary first step towards recycling.
Figure 8: Different NIR-spectra for PLA-materials [Kreindl, 2012]
Conclusion & workshop results
The introduction of biopolymers, especially on the packaging market, is an important step out of the
perspective of a sustainable resource policy and development. The gradually substitution of fossil raw
materials by renewable biogenic raw materials will become a major challenge in the future
development of various industries. LCAs for different bioplastic materials usually show a positive
effect on the environment. It is often a matter of setting specific boundaries in the overall system. The
production of biopolymers should never be in direct competition with food. Worldwide the amounts
of packaging are increasing. Referring to the hierarchical principle of the EU Waste Framework
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Directive 98/2008, prevention (avoidance) and reuse of packaging materials are better than recycling
or thermal treatment approaches. Landfill of packaging waste, even bio-based and/or biodegradable, is
not an option in modern waste management strategies. Biodegradability of plastic can be useful under
certain circumstances. It is not suitable to prevent littering. Today, the critical mass for recycling of
biopolymers is still too small. The ongoing expansion of production capacities will continuously
adapt the price levels for biopolymers (approaching conventional polymers) and has also an influence
on the economic efficiency of recycling. Recycling of bioplastics is a big challenge for the future.
Therefore, sensor-based sorting technologies are useful and do support recycling.
At the moment, there is a discussion going on about the forced introduction of bioplastics on the
packaging sector. Less degradability, more the green image of renewable raw materials is the driver of
this development. Future production in terms of sustainability thinking is to replace fossil-based
resources by natural raw materials. New approaches accompanied by a nearly 100 % substitution of
ending resources are in the focus. The use of vegetable and animal (production) waste becomes an
important role. During the workshop and critical dialogue on the future of packaging – What roles
have biopolymers in future packaging industry? – some positions from the perspective of different
share- and stakeholders had been discussed. Questions are dealing with the following topics (no
priority ranking):
1.) How many labels does the market need?
2.) Must bio-based products be biodegradable?
3.) What about sustainability of biopolymers?
4.) What end of life scenarios for biopolymers exist?
5.) Which compromises have to be made today and in the mid-term when there is a shift of
packaging products towards bio-based plastics?
ad 1.)
There is a need in educating all shareholders (policy, trade, business, consumers, actors in waste
management). Today a great variety of labels for biopolymer packaging coexists. They often have
different meanings. Statements about re-use options or preferred disposal methods should be
consistent and easy to understand. The goal is to implement a transparent, comprehensible and
distinctive label to characterize the two main groups of biodegradable and non-biodegradable
biopolymers.
ad 2.)
Biodegradability can be an advantage in certain fields of applications. It depends on the waste
management infrastructure and the existing recycling capacity. However, decomposition influenced
by external parameters does not necessarily mean, that biodegradable polymers are suitable for home
composting or even for industrial composting. Degradation under industrial composting conditions is
only possible for biodegradable biopolymers. Conventional non-biodegradable polymers (misthrow)
in biowaste fraction interfere with the composting process. An optical distinction between
biodegradable and non-biodegradable plastics is not possible. Again, public education and a rigorous
information policy are mandatory in order to operate a functioning waste management.
ad 3.)
Clear definitions related to biopolymers have to be made. There are numerous life cycle analyses
(LCA) for bioplastics. Positive or negative impacts on the environment are in most cases, depending
on the chosen system boundaries. There is a need for a uniform certification system. For this reason,
these studies should be critically examined. Sometimes emotions and the media preload of the topic
(film plastic planet) play an important role in this context. Today, biopolymer blends often consist of
a quite low content of renewable raw materials. The future challenge is to reduce the dependence on
fossil-based resources.
ad 4.)
In order to push different end of life scenarios for biopolymer packaging, it is necessary to integrate
consumers into the development process. Consumers are the link between the products on market and
waste management. Different end of life options for biopolymers exist: feedstock recycling or cascade
Gernot Kreindl, End of Life and Waste Management of Bio-based Products and Composites
use is better than thermal utilization, composting/fermentation or even landfilling. Today, the market
penetration of bioplastics is too low to make recycling profitable. Economic incentives (packaging
ordinance) should be created to support a sustainable development in the future.
ad 5.)
Different price levels for conventional and renewable packaging materials have an influence on the
bioplastic market. The short-time availability in addition to the technical performance of biopolymers
plays a significant role. All in all, the consumer defines the rules of the game. The acceptance by the
consumer coupled with a positive image of the product and its packaging are very important.
Bioplastics should never be in competition with food production. Besides ethic aspects, fair trade
associated with the assurance of credibility are important to successfully establish bioplastics in the
market.
References
Endres, H-J. (2011): Engineering Biopolymers: Markets, Manufacturing, Properties and Applications.
Carl Hanser Verlag, Munich.
Plastics Europe (2011): Plastics –the Facts 2011. Plastics Europe, Brussels.
Windsperger, A.; Brandt, B. (2010): KLIKU Klimaschutzpotentiale beim forcierten Einsatz biogener
und konventioneller Kunststoffe. Neue Energien 2020, Wien/St.Pölten.
Homepage European Bioplastics (2011): http://www.european-bioplastics.org
Kreindl, G. (2011): Technische Möglichkeiten der Nahinfrarotsortierung von gemischten Industrieund Gewerbeabfällen. In: Rohstoffe und Recycling – Tagungsband 3. TK Verlag, Berlin.
Kreindl, G. (2012): Entwicklung eines umfassenden Sammlung und Entsorgungskonzeptes für
biologisch abbaubare Kunststoffverpackungen unter Berücksichtigung der abfallwirtschaftlichen
Situation in Österreich – Heute und in der Zukunft (Working title). Thesis (previously unreleased),
Leoben.
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