6 The Increased use of cogeneration would optimize the energy efficiency of incinerators.
7 Improved recycling technology could reduce the energy needs for the recycling process or minimize the part of the collected
waste that ends up as residual waste.
4.3 Relevance of findings in the UK context for plastics
The plastic waste category is dominated by plastic packaging, estimated to comprise around 8% of the household
waste stream in the UK. Of this, around 22% is collected for recycling. At the time of writing, the target for
plastic packaging is a recycling rate of 29%. The study has clearly highlighted that mechanical recycling is the
preferable option for managing plastic waste, shown in the table below. The indicators that have been chosen to
be displayed in Table 91 are those corresponding to the main environmental issues the UK is facing. It is
interesting to note that the ranking presented below also corresponds to the findings from study no 2 (Shonfield,
2008) which was conducted in a UK context. Nevertheless, in that specific study, pyrolysis appeared preferable to
recycling for both energy demand and eutrophication while incineration performed worse than landfill regarding
climate change.
Table 91 Overview of the best and worst end-of-life options for managing plastic waste based on the results of the study^Plastic^ waste^ management^
Indicator Best option Worst option
Number of
studies
Climate change Recycling Incineration/Landfill 8
Depletion of natural resources Recycling Landfill 4
Energy demand Recycling/Pyrolysis Landfill 7
Acidification Recycling Landfill 4
Eutrophication Recycling/Pyrolysis Landfill 4
Recycling and material quality
The analysis conducted highlighted that mechanical recycling is indeed the best option regarding climate change,
depletion of abiotic resources and acidification. As CO 2 emissions and air pollution are issues of specific interest in
the UK it would be beneficial to further develop plastic recycling.
There is some concern about the need to wash the material prior to recycling, especially for packaging which
represents around one-third of the plastic consumed in the UK as illustrated in Figure 48. Washing needs have
not been taken into account in the selected studies but could affect the energy balance in the event that hot
water is used for washing.
Additionally, in the case of plastic waste arising from electronic and electrical equipment or end-of-life vehicles,
the preliminary recovery operations prior to the recycling process (sorting, crushing, etc.) may require some
energy. Incineration could then become a preferable option on this aspect, since the balance between the two
was already tight. The plastic waste recovered from these types of wastes can also be of low quality (mix of
different plastic types and colours), thus leading to low quality recycled products for which an end-market might
not be available. However, certain WEEE recycling channels seem promising. For instance a recent LCA found
that significant environmental benefits can be gained from producing recycled high-impact polystyrene
resin from discarded televisions compared with producing virgin high-impact polystyrene resin (Frey & Dowling,
2009), despite the transport and recycling impacts. Nevertheless, the data for recycled resin was confined
to one manufacturer in that study therefore the LCA results cannot be generalised and further research is needed
to come up with reliable conclusions regarding the recycling potential of WEEE.
Another problem has also arisen due to the European Commission REACh^5 regulation which came into force in
2007 and that regulates the production and use of chemical substances. The regulation does not apply to wastes
themselves but some questions remain to be answered regarding the recycling of products containing substances
covered by REACh. Indeed the content of those substances will have an influence on the recycled products
quality and thus on their value.
(^5) European Commission Regulation on the Registration, Evaluation, Autorisation and Restriction of Chemical Substances
(REACh)