LCA of beverage container production, collection and treatment systems
The primary objective of this study is to assess and compare the potential environmental impact of beverage container production with different collection and treatment systems in Norway. Three major systems for collection and treatment of PET bottles have been analysed:
• Collection of PET bottles using Infinitum’s existing deposit system with Reverse Vending Machines in grocery stores. This system is modelled using actual, known collection rates.
• Collection of PET bottles using Green Dot Norway’s kerbside system for plastic packaging (no deposit). This system is modelled using two different scenarios for collection rates.
• Collection of PET bottles together with residual waste to incineration. This system is modelled as a hypothetical system where bottles and cans follow the residual waste stream and no recycling is done.
Furthermore, the project has analysed different optimisation scenarios with regard to increased collection rates in Infinitum’s system and rates of recycled PET in the bottles. Similar optimisation scenarios have been analysed for Infinitum’s collection system for aluminium cans.
The study has been commissioned by Infinitum AS, the corporation that runs the deposit recycling scheme for beverage containers in Norway. The container types included in their scheme are made of aluminium, steel and plastic (PET). A reference group was established in order to ensure that the assumptions regarding the different systems were objective and comparable, which is also a requirement for comparisons of systems in accordance with LCA standards.
Life Cycle Assessment (LCA) has been performed to assess the potential environmental impact of the systems for the following impact categories: Global Warming Potential (GWP), Abiotic Depletion Potential (ADP), Acidification Potential (AP) and Eutrophication Potential (EP). The systems are modelled according to the Cut-Off System Model, which follows the “polluter pays principle”. The underlying philosophy for this approach is that the primary (first) production of a material is always allocated to the primary user of the material. If a material is recycled, the primary producer does not receive any credit for the provision of any recyclable materials. As a consequence, recycled materials bear only the impacts of the recycling processes. Nevertheless, the incineration of waste is allocated completely to the treatment of the waste. The burdens lay with the waste generator, according to the polluter pays principle.
The functional unit for all the analyses is: Production, collection and treatment of PET bottles and aluminium cans used for distributing 1000 litres of beverage to consumers.
The Infinitum system gives clearly the lowest climate impact as the increased impact is 11%, 24% and 78% for the Green Dot Norway systems with 70% and 50% collection rates and the Incineration system, respectively. Based on Norwegian consumption of PET beverage containers for 2015, these figures represent potential annual increased climate impact of about 7 000 tons, 15 000 tons and 50 000 tons CO2-eq, respectively. Production of virgin PET is the major contributor to climate impact, but incineration of PET (not collected for recycling) is also a notable contributing activity. Hence, the Infinitum system performs better than the GPN system due to higher collection rate, which means less emissions from incineration of PET not collected for recycling. For the other environmental indicators assessed (Abiotic Depletion, Acidification and Eutrophication Potential), as well as for littering volumes, the Incineration system performs worst, mainly due to the assumption of 100% virgin PET in the bottles compared to 80% in the recycling systems.
In order to focus on the differences between the systems with regard to collection and treatment, the results are also presented without the contribution from PET production. The Infinitum system performs clearly best with regard to climate impact due to the lowest incineration emissions. For ADP (use of fossil energy) and Acidification, the Infinitum and Incineration systems perform best due to lowest transport burdens while the Green Green Dot Norway system performs best for Eutrophication. For climate impact, incineration is the dominating activity while transport is dominating for ADP (use of fossil energy). For Acidification and Eutrophication, the reverse vending machine (mostly production of electric components) gives the major contribution in the Infinitum system, while incineration and transport are both significant in the GPN and Incineration systems. It should be noted that the collection and treatment activities represent less than 10% of the total impact (when including PET production) for the systems (except for climate impact). Thus, one should carefully look at these results without considering them as part of the complete systems.
Production of virgin PET is the major contributor to all the analysed environmental indicators. Hence, the most important factor for improving the environmental impact of PET bottles systems is to produce PET bottles with as high share of recycled material as possible. Furthermore, high collection rates of the used bottles are also important, as the higher the collection rates, the better environmental performance is achieved. This is documented by analysing optimised scenarios for Infinitum’s PET bottle system and also for the aluminium can systems. The major reason for the large improvements when shifting to recycled material at the expense of virgin material is that recycled material production has a much lower environmental impact compared to virgin production.
However, increasing the share of recycled PET (rPET) and aluminium also depends on the available rPET/recycled aluminium at the market, which again is affected by the supply of recyclates with a sufficient quality for new bottle/can production. It is therefore important to implement collection systems which are able to contribute to closing the loop for these products. Hence, when comparing different systems, one should look beyond the collection rate as such, also taking into consideration the collection systems’ potential of supplying the market with high quality recyclates acceptable for new bottle/can production.
This is particularly important for the PET system, as the collection system to a large extend might affect the quality of the collected material. When PET bottles are collected together with other packaging (both food and non-food packaging), the quality and possibilities for reaching food grade quality of the recycled material is harder. Hence, from a hygienic point of view, the input material for bottle-to-bottle recycling should preferably be bottles or containers from food applications. It is therefore likely to assume that the quality of PET recyclates collected together with other non-food packaging is lower compared to the quality of PET collected in a deposit system. On the basis of this, it can be concluded that the Green Dot Norway system has a lower potential of closing the loop for PET bottles by delivering bottle-grade recycled PET “back to the system” as the collected PET material most likely will be recycled into other applications.
The existing Infinitum system has a large potential for environmental improvements. This is illustrated by assuming increased rPET shares in the bottles from the assumed existing rate of 20% to 60% due to more bottle-to-bottle recycling. This seems likely, as the existing collection rate is 87%. The reduced climate impact is calculated to 45 kg CO2-eq per functional unit, which on an annual basis (based on data for 2015) represents 27 243 tons CO2-eq. This amount equals the annual CO2-emissions from about 18 500 passenger cars. Similarly, increasing the recycled content in the aluminium cans from 20% to 60% represents an annual reduction potential of 80 500 tons CO2-eq, which corresponds to annual CO2-emissions from about 50 000 passenger cars.
A prerequisite for achieving high rates of recycled PET in bottles is that they are easy to recycle, thus not containing unnecessary additives, coatings, colours, etc. Design for recycling is therefore an important issue for preform producers.
The environmental impact of littering has not been assessed in this study as the included environmental impact categories do not measure this effect. However, based on data from 2015, the potential annual littered PET volume from the Infinitum and Green Dot Norway systems, as well as the Incineration scenario have been calculated to about 500 tons, 1000 – 1250 tons, and 1500 tons PET, respectively. These littering volumes might cause problems related to microscopic plastic fragments available for fish and animals, as well as esthetical problems. In addition, they represent a loss of resources.