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Collection, as the first stage of the recycling process, and pre-processing to increase waste stream purity constitute key operations for achieving high recycling rates and a closed loop in the circular economy. For wastepaper recycling in Hong Kong, it is the semi-formal-informal recycling (SFIR) sector that plays a central role in both stages. This study analyses the so far little explored SFIR stakeholder network in Hong Kong and sheds light on value chains, recovered waste paper quantities and the impact of policies on the sector. The findings show that SFIR stakeholders reclaim 55.6 t/recycling station/month of wastepaper and thereby achieve about a 5.7 times higher reclaim rate than the formal-private recycling system. Critical to this achievement is the SFIR transaction network, which enables its stakeholders to develop a value chain and thereby generate an added value of around 1900 HKD (243.9 USD/t) for wastepaper. Given limited circular structures in Hong Kong, financial subsidies are critical to sustain the SFIR's operations over the short-term. However, over the long-term legalization and integration of its stakeholders are necessary to ensure an economically and socially sustainable wastepaper recovery system in Hong Kong. [Display omitted] • Qualitative & quantitative analysis of the semi-formal-informal recycling (SFIR) sector. • The SFIR's wastepaper value chain achieves a cumulative added value of 1900 HKD/t. • The SFIR recovered 5.7 times higher capacities than the formal system in 2021. • Financial support can enhance the SFIR sector's recovery capacities. [ABSTRACT FROM AUTHOR]

The inclusion of the informal recycling sector (IRS) in a circular economy (CE) is challenging and it is gaining increasing attention by the academic community in an exponential yet fragmented way. In this narrative review, we demarcate the direct and indirect contributions of the IRS to various domains of the CE by drawing knowledge from relevant literature. First, we capture the modi operandi of different forms of recycling value chains into a typology. We do so based on distinct foci and policy approaches towards the IRS which have been adopted across different countries. Second, we synthesize various threads of information on reported forms of collaboration, tensions, and challenges in the context of urban waste management, into a conceptual framework to facilitate transitions towards circular and inclusive wise-waste systems. Finally, we discuss important aspects related to circular business models and integration approaches towards the IRS, and we propose avenues for further research. [ABSTRACT FROM AUTHOR]

[Display omitted] • Inequalities affecting the circular economy of plastic waste remain largely unknown. • We address this gap through a case study of Thailand. • Social inequalities are embedded in and perpetuated by the circular economy model. • These inequalities therefore compromise the model's overall objectives. • State deficiencies exacerbate informal sector inequalities. [ABSTRACT FROM AUTHOR]

By 2030 the sales of electric vehicles (EV) are set to increase 6 to 30 folds compared to the levels of 2019 thereby leading to an increase of discarded EV batteries. This creates a challenge to sustainably handle the waste by repurpose and recycling the EV batteries. In this paper, a method to analyze the usage of EV batteries throughout their life cycle in light of their contributions to a circular economy is proposed. The study is divided into two stages which are modelled with mixed-integer linear optimization. Stage 1 considers the optimal charging strategy for an EV and stage 2 represents the second-life of the EV battery as stationary energy storage in a residential building. Six scenarios were created for both stages; stage 1 includes smart charging and/or Vehicle to Grid (V2G) and stage 2 adds demand side management and/or PV self-consumption maximization to stage 1. A sensitivity analysis is performed to assess the impact of electricity prices. The results are analysed to assess the operational lifetime and economic savings for an EV owner. The results show that using second-life batteries in a residentail building can extend the lifetime of an EV battery by 3–5 years while allowing savings above 23%. • A two stage algorithm was developed for optimal charging strategy of an EV and SLB. • Six scenarios were modelled to quantify the savings and lifetime of an EV battery. • The usage of an EV battery for SLB can extend the lifetime from 3 to 5 years. • Compared to the baseline scenario SLB can result in economic savings of 24%–77%. [ABSTRACT FROM AUTHOR]