A Circular Economy for Coffee Capsule Waste

A qualitative exploration of chemical recycling and advanced sorting of plastic aluminium coffee capsule waste and an analysis of the system barriers and potential interventions to transition to circularity

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Abstract

In recent years, an increasing amount of plastic packaging waste has drawn attention from consumers, media and policymakers alike. To tackle this, the concept of a circular economy (CE) is well established in Europe through the implementation of the European Strategy for Plastics in the Circular Economy. The strategy places an importance on improving recycling to increase the amount of high value materials in circular loops. An innovation intended to achieve this is chemical recycling, which provides an alternative to the current mechanical recycling system. Improvements in recycling are also being met with innovations in the sorting of the plastic packaging waste to improve overall recyclability. One such packaging waste that can benefit from these innovations is composite plastic aluminium packaging. The example taken in this report is that of single-use coffee capsules. These are incinerated due to their poor recyclability in current mechanical recycling systems, leading to a loss of materials, counteractive to the CE approach. This review outlines the end-of-life of such packaging and explores chemical recycling and sorting technologies that can help to realise a CE for the waste. The work also includes a qualitative exploration of the overall packaging waste system to analyse barriers towards a CE and propose interventions for the CE transition. The work gathers information on different chemical recycling and sorting technologies through semi-structured interviews with practitioners and a review of scientific publications. In line with CE strategies, solvent dissolution is chosen as a potential chemical recycling technology for the coffee capsules. Subsequently, the collection and sorting of the capsules is outlined through flow diagrams, and a sorting protocol is drawn up for isolating a feedstock of the capsules for recycling with solvent dissolution. Two promising sorting technologies are highlighted here: NIR scanners with deep learning and packaging markers. The overall packaging waste system of the coffee capsules is then explored in three main steps; (1) a mapping of stakeholders and flows of materials, money and influence, (2) semi-structured stakeholder interviews and (3) mapping of CE barriers along four key pillars: technological, regulatory, market and cultural. The results of the system study reveal a variety of interconnected barriers across different system levels. While key technological barriers exist in the form of limited industrial demonstration, several other barriers were found more insightful. These include a regulatory focus on material circularity, limited stakeholder awareness for the environmental impacts of different CE strategies, a lack of design guidelines for composite packaging waste, limited funding for industrial experimentation and a lack of consumer awareness of packaging sustainability and preference for convenience. Following these findings, four system interventions are proposed to overcome the mentioned barriers and facilitate recycling of the coffee capsule. Overall, it is seen that any intervention requires significant further work and an understanding of the root causes, as the identified barriers are interconnected, and one may cause a chain reaction to others. The interventions proposed here should be taken as a guiding point of departure, and further work is needed to validate the interventions and their potential impact for change.