PUBLIKASJON

Publikasjonsnummer

OR.07.22

Publiseringsår

2022

Type

Publikasjon

Life cycle assessment of household plastic waste treatment in Norway

This study was commissioned by Plastretur (Green dot Norway) and was carried out by NORSUS. The overarching goal has been to quantify the environmental impacts of Plastretur’s system for collection and material recycling of plastic packaging waste from households in Norway, and to identify factors which have large impacts on the results.

Life cycle assessment (LCA) methodology was applied to calculate the environmental impacts of collection and treatment of plastic waste resources, as well as the avoided emissions when recycled material substitute virgin material, and when energy from waste substitute other energy carriers. The current system of sorting and recycling plastic waste was compared with an alternative with no sorting, where plastic waste goes to incineration with energy recovery together with residual waste. The assessment is made for the treatment of the amount of plastic waste sorted from Norwegian households during a year.

The plastic collection of household plastic waste in Norway consists of three systems, and each system is analysed and summarised to quantify the annual environmental impacts:

  • sorted at source versus incineration
  • sorting at ROAF sorting facility versus incineration and
  • sorting at IVAR sorting facility versus incineration

Note that the results for the three systems are not comparable since different functional units (representing different plastic compositions and quality) have been used for each system.

Specific data were collected, e.g. from Plastretur, ROAF and IVAR, to represent these systems to the extent possible. When specific data were unavailable, generic data were utilized. Four environmental impacts were assessed, including climate change, freshwater eutrophication, fossil resource scarcity and fine particulate matter formation.

The results from the study show that the Norwegian system for sorting and material recycling of plastic waste contributes to a reduction in greenhouse gas emissions of approximately 72 300 tonnes CO2 equivalents compared to the alternative with no sorting where all plastic is incinerated instead. The system for sorting in households contributes to a reduction of approximately 51 000 tonnes CO2 equivalents, and the sorting facilities of ROAF and IVAR contribute to a reduction of approximately    10 500 and 10 800 tonnes CO2 equivalents, respectively, compared to incineration. In municipalities with sorting in households, each kg sorted contributes on average to an emission reduction at 2.0 kg CO2 equivalents compared to the same amount being incinerated.

The results from this study show that sorting and recycling of household plastic waste is preferable to incineration with energy recovery in terms of climate change and fossil resource depletion. In terms of fine particulate matter formation and freshwater eutrophication, on the other hand, incineration with energy recovery gives lower impacts. For fine particulate matter formation, this is a result of higher avoided impacts from incineration compared to avoided impacts from recycling and incineration of plastics in the systems for sorting and recycling of plastics. For freshwater eutrophication, this is due to impacts from the resources needed for recycling processes, such as electricity, while incineration avoids contributions to freshwater eutrophication when substituting Norwegian district heat generation.

Critical factors affecting the results include:

  • Sorting rates for each plastic type
  • The quality of the plastic and what it substitutes
  • The market for recycled plastics

Transport and energy use have low impacts on the results.

In the future, Plastretur is advised to collect more specific data from the sorting- and recycling facilities, which to various extent had to be modelled using generic data. More information on recycling rates per plastic type, the quality and market of recycled materials and what type of material that is substituted by these recycled materials would be beneficial. Furthermore, Plastretur is advised to select sorting- and recycling facilities that produce high quality recycled material that in turn can substitute virgin plastics.

This project has not included a comparative assessment of the different sorting systems (sorting at source compared with residual waste sorting facilities). In such a study the comparison must be done based on the amount of plastic waste generated in the households. As more data is available for the different systems, it is recommended to set up analyses with the aim of a direct comparison of the different systems to better understand the implications of choosing one system over the other. In such a study, it would be interesting to address under what circumstances that one of these systems becomes preferable to the other. This could be done by, for example, assessing how well consumers need to sort the household plastic waste for the sorted at source system to be environmentally preferable over a sorting facility system where plastics are disposed with the residual waste.

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