In the face of increasing environmental challenges such as resource scarcity, biodiversity loss and water, air and soil pollution, the current consumption rate of resources is testing the earth’s physical limits (Bansal and Song, 2017; Geissdoerfer et al., 2017; Esposito, Tse and Soufani, 2018). Of all products, electrical and electronic devices are especially challenging for sustainability considering their demand, resource usage and the challenges in waste management. In the EU 12.4 million tons of EEE is put on the market, of which 4.7 million tons of WEEE is collected. This is about 10.5 kg of collected e-waste per person, per year in the EU alone (Eurostat, 2020). Especially for small electronics the substitution rate is high and products are replaced before reaching their functional lifetime because of the introduction of newer, better performing models.
To address these challenges the concept of the circular economy emerged as an alternative to turn this single-use lifestyle into one in which resources are circulated (Geissdoerfer et al., 2017). Electronics also provide an especially interesting product group regarding the circular economy, not only for the challenges listed above but the development phase for electronics is also highly time-consuming when circularity is a requirement. Considering this industry, the transition to the circular economy requires the implementation of circular strategies in the day-to-day business as well as along the product lifecycle. Clear guidance on how to achieve this is however not always easy to find in academic literature. Every circular economy expert has a different area of expertise, creating a scattered range of guidelines, frameworks, indicators and approaches for designing, measuring and implementing circular economy principles in business. Business in practice therefore requires a navigation aid to select and properly implement circular economy methods for a particular business. This thesis therefore answers the research question “How can appropriate circular economy methods be selected by OEMs to support the transition towards a circular economy in electronics?”
This thesis studies six companies within the electronics industry on their use of CE methods to eventually develop a navigational aid for original equipment manufacturers in the electronics industry. The case comparison led to four distinctive groups on how companies select and apply CE methods as well as a set of generic insights. Together these were applied in the development of the Circular Economy Method Compass. The CE Method Compass is a holistic approach to navigating circular economy methods that offers original equipment manufacturers (OEMs) in the electronics industry guidance in the transition to the circular economy and the development process of circular products and services. The CE Method Compass summarizes a comprehensive overview of available circular economy methods over five categories of CE methods: differentiation, collaboration, physical architecture, consumer engagement, and evaluation and assessment methods. The categories hereby cover the development process from the initiation of a circular vision to the final assessment of a product or service. The five categories combined have the opportunity to enable the R-strategies, creating circularity. The CE Method Compass can furthermore be used by both companies that wish to enhance their circular economy strategy as by companies new to the circular economy. The CE Method Compass hereby supports the use of CE methods by OEMs in the electronics industry and has the ability to increase the circularity of the sector.
This is valuable because achieving circularity in electronics is a challenging assignment. The CE Method Compass hereby provides an overview of where and how circular value can be achieved. Overall, the CE Method Compass facilitates navigation and broad application of CE methods. The compass is however only a first iteration of such a navigational aid and future research is needed to develop it further.

The municipality of Amsterdam is swiftly advancing its climate neutrality aspirations within the EU’s Climate Neutral Cities Mission. To accelerate this transition, the municipality has set the target to fully utilize suitable rooftop surfaces for solar panels by 2050. Yet, economic incentives prompt households to replace PV panels prematurely, leading to functional panels being discarded for low-value recycling. This study focuses on evaluating the environmental consequences of lifetime extension strategies at city scale, using Amsterdam as a case study. Employing an innovative prospective Life Cycle Assessment (LCA) approach, this research examines net environmental impact across multiple scenarios, derived from a General Morphological Analysis (GMA). The findings indicate that, despite rapid technological advancements, retaining older panels on buildings proves environmentally preferable to early disposal. Moreover, re-installing functionally disposed panels holds the potential to drive a significant reduction of 790 to 1910 million kilograms of CO2-equivalent emissions, or 126 to 327 million euros in shadow costs. To seize the opportunity for reuse, the municipality is advised to initiate pilot projects urgently and collaborate with European end-of-life management stakeholders. Future research is needed to incorporate the influence of novel recycling practices, emerging circular technologies, regional market shifts toward Europe, and the implications of resource independence. This study underscores the need for sustainable PV panel management strategies to accelerate Amsterdam’s climate-neutral journey.

Mountains of solid waste in landfills and rivers of plastic in oceans have become a symbol of modern society, more so in developing countries.

Asia is responsible for 71% of the world’s mismanaged plastics (Neo et al., 2021) with India ranking 12th in the world (Shanker et al., 2022). In contrast, several studies have determined that India has one of the world's highest plastic waste recycling rates, between 40-60% (Shanker et al., 2022). These two seemingly contradictory pictures make India, an interesting choice for a case study on plastic waste management in the developing context.

There are unrecognised warriors in the Global South who have been instrumental in achieving high plastic recycling rates. These are the informal waste workers who work outside the mainstream formal system and collect recyclable material from households, garbage dumps, or even landfills directly. In fact, India owes its successful plastic recycling rate in part to the informal sector.

While there have been studies to quantify the plastic waste management system of India, there is little known about the extent of the contribution of the informal sector to plastic recycling due to the ‘invisible’ nature of its operations.

This study attempts to expand the existing body of knowledge on the contribution of informal sectors in achieving high plastic waste recycling rates in India, by focusing on the test case of the city of Chennai in South India.

In that regard, this paper aims to address the following two sub-research questions related to the plastic recycling value chain: (1) What are the material flows of household plastic waste along the formal and informal recycling value chain of plastic waste in Chennai, and where do exchanges between the two sectors occur? (2) What are the data gaps in estimating the material flows, and the barriers and challenges in building a comprehensive MFA of plastic waste in the developing context?

To answer the first question, the tool Material Flow Analysis (MFA) is used to estimate the recycling value chain of plastic waste generated in Chennai. The plastic waste flows from the stage of waste generation in households to End-of-Life management are covered. The interplay between formal and informal waste sectors is included wherever present. To obtain data for the MFA model, secondary data from peer-reviewed literature, and other literature like reports, government publications, etc. are combined with primary data collected via field visits and interviews with experts.

Data unavailability is one of the biggest barriers to building a comprehensive MFA of plastic waste management system in Chennai, particularly the contribution of the informal sector. Thus, qualitative data obtained from the interviews about the barriers to data collection and the social issues that keep the system hidden from the outside is used to discuss the second research question. Finally, possible solutions to circumvent these issues are explored to promote the flow of information among internal and external stakeholders to envision a more effective and fair plastic waste management system.

The study highlights the importance of involving informal waste pickers in the plastic waste management process, as they play a significant role in achieving a circular economy through recycling plastic waste. By recognizing the contributions of the informal waste sector, this study also aims to improve the lives of waste pickers and promote their inclusion in the formal waste management sector.

Today’s society relies significantly on the use of plastics of all kinds. While the material provides many benefits, plastic pollution poses a heavy threat to the environment. To reduce the environmental impact of plastics while still benefitting from their use, various certifications aim at labelling different plastic products as sustainable. To ensure that those certifications really label plastics that contribute to sustainable development, it is important to analyse which labels are scientifically sound and useful instruments to enhance environmental standards, and which might contribute to greenwashing. However, a certification can only be as good as the practical implication it has. The example of Berdal Rubber & Plastics BV, a Dutch producer of plastic buckets and tubs, shows that a key challenge arises from communicating the importance of adopting such certifications to business customers, in their case, especially in the building and DIY industry. Hence, this research tackled the following research question: How can the scientific soundness of sustainable plastics certifications in the European building and DIY industry be assessed and how can the importance of using such certifications be successfully communicated to the buyers and end-users of plastic products? To answer this research question, inductive research making use of a mixed-methods approach has been conducted, in which Berdal served as a case study. As a first step, this research developed an analysis framework for certifications, then, it researched what a successful communication strategy for certifications that includes said framework can look like. A major challenge that has been identified is to change the sometimes still unfavourable attitudes towards certifications and sustainability found within the building and DIY industries. Additionally, the low understandability of certifications limits their use, while being difficult to target by communication strategies. However, communication on certifications and sustainability can be more successful when it considers certain aspects. Especially the dialogue with stakeholders and credibility through proactiveness are seen to be important. Target group specific communication that focusses on personal relevance is found to be another aspect to consider. Here, the role of the framework can be to present information in a clear and detailed way, and to be an instrument to point out the advantages a specific certification can have for the communication’s receiver. For the specific situation of the case study of Berdal, it has been found that setting up a reciprocal dialogue, especially with their buyers, and emphasising the credibility of their message about certifications by focussing on their reliability and standard setting can be beneficial. Additionally, the focus of communication should lie on the personal benefits of their stakeholders individually. The framework for Berdal as a plastics producer can be used to transparently show why certain certifications have been chosen or how they compare to others.

Aquacultures are rapidly increasing worldwide to meet the rising protein demand caused by population growth. However, commonly used fish feed products are known to harm the environment while depleting natural species. Various microbial protein forms are thus being investigated, such as those using hydrogen-oxidising bacteria, referred to as MP. This study investigates MP’s environmental performance over conventional feed products as overall
advantages and disadvantages remained unclear based on previous publications.

A four-phase explorative scenario framework for assessing novel technologies was used, further developed from recent studies. Based on a literature review of MP’s environmental performance, the ammonia and heat source used needed further evaluation. At the same time, previous studies displayed limitations related to CO2 allocation, continuous energy and nutrient supply, energy
grid stability, the readiness of the assessed technologies, the cost of production, and other influencing socio-economic factors. An attributional cradle-to-gate life cycle assessment (LCA) was conducted to determine an optimal system performance at a pilot-scale rooted in the literature findings. Subsequently, technical and socio-economic parameters were evaluated to influence MP’s progressive environmental performance.

Consequently, an ex-ante LCA compared MP production scenarios over time, differing in energy sources and production scales, against soybean meal (SBM). Even at high technical development, comparative results closely aligned, yet MP using geothermal energy showed a slight overall advantage over SBM after normalisation, in contrast to hydro and bioenergy displaying no real benefit. When oxygen (O2) was recycled, the former showed an overall
advantage over the incumbent at high production capacity. A total disadvantage would be expected for the latter, considering continuous H2 and NH3 supply. Further research should focus on integrating recycled phosphate, green H2 in the steel industry, differences in databases regarding water use for hydropower plants, and scenario analysis of the incumbent system. Besides these findings, the developed framework contributes toward the comparative assessment
of novel technologies against established ones.

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.

Life Cycle Assessment (LCA) models are inherently uncertain due to the model structure interacting with the model inputs and modeling choices. The methods of sensitivity analysis (SA) aim at retracing the causes of the uncertainty of the results of a model. This work takes apart the methods of uncertainty propagation, SA, and LCA, and identifies the requirements of appropriate SA methods for LCA. Global input space assessment and inclusion of correlation are identified as important factors which both analytical and sampling SA methods have issues addressing. An analytical expression for covariance is formulated that combines research on the uncertainty propagation methods to address the posed requirements. Its performance is tested and shown to be promising, but further manipulation is required for practical application in SA for LCA in the future.

In May 2019, the Dutch Council of State rejected the national approach for reducing nitrogen emissions in Dutch nature. Farmers were targeted by the policy change: all licenses for agricultural expansion were revoked, affecting the financial livelihoods of farmers. Farmers did not take this well and, using social media platforms, started organising large-scale demonstrations. Twitter flushed with posts about the demonstrations, and pictures and videos of the event went viral. Demonstrations result from social unrest, and social unrest starts with public dissatisfaction. The Nitrogen Crisis showed it is in the interest of decision-makers to monitor what negative feelings the public holds towards policies and act on these, before these feelings grow into social unrest. Twitter is a social media platform many users come to for expressing their opinions. Because of this, this study looks at what insights can be derived from Twitter about events, like demonstrations, that took place during the Nitrogen Crisis. For this, this study applies two Natural Language Processing methods: sentiment analysis and topic modelling (LDA). These methods are combined in order to create more insightful and interpretable results than the methods individually could provide. Two interviews are held with an expert on the Nitrogen Crisis to provide context on the crisis and to identify major events that received a lot of media attention. The events are plotted with- and compared to the results of sentiment analysis and topic modelling. In doing so, the following research question is answered:
How can sentiment analysis and topic modelling be applied to Twitter data to provide insights for decision-makers retrospectively about major events during the Dutch Nitrogen Crisis?
For sentiment analysis, two Dutch sentiment analysis tools are implemented and compared to the sentiment scores of 100 tweets by three annotators to select the best performing one. For topic modelling, a grid search is performed to choose the combination of timeframe and number of topics that result in the set of topic models that have the highest mean topic coherence. Also, a method is proposed for using topic models to represent changes in the topics discussed on Twitter over time. This is used not only to compare subsequent topic models per sentiment that are one week apart, but also topic models that are 4 weeks apart.
This research develops a fully functioning pipeline for collecting and processing tweets, applying sentiment analysis and topic modelling and plotting the outcomes. This pipeline has been validated at various points, leading to a scientifically viable methodology.
Unexpectedly, it is not sentiment analysis or topic modelling results that have the most obvious connection with the events identified: it is an increase in tweets during events. Therefore, while lacking better tools, decision-makers are recommended to monitor pre-determined topics on Twitter and implement a way to be notified when a significant change in volume of tweets takes place. The combination of sentiment analysis and topic modelling as implemented in this research is either not advanced enough to provide useful information to decision-makers, or sentiment analysis and topic modelling simply cannot provide insightful results on the Dutch Nitrogen Crisis. However, because there is an extensive amount of research applying these methods to social media data around various political events with valuable results, it is recommended to perform more experiments with this approach, and the quality of each research step needs to be further improved in order to draw final conclusions on the usefulness of the combination of sentiment analysis and topic modelling for decision-makers during policy crises. Various improvements for each step in this research are suggested to gain more precise, insightful and interpretable results. In summary, this study and the pipeline it proposes can serve as a solid basis for further development into a process that provides ready-to-use information to decision-makers.

The aim of this research is to implement the effects of artificial light at night on moths in a model that functions as an impact category in the life cycle assessment methodology. The model defines the attraction of moths in a specific region of influence. This attraction might result in multiple direct and indirect effects that could lead to the reduction of moth population, due to an increase in mortality. The region of influence is expressed in square meters and is the area where the intensity of streetlight is higher than the intensity of the background light, which includes the moon- and starlight combined with skyglow of a certain region. The first prototype is tested in two districts of Berlin to demonstrate how the method is used in a region and to show the limitations and the different scenarios per intensity class and mounting height of the streetlight. Practitioners should be able to use this model to implement this in life cycle impact assessment. Weather conditions, moon phase, and skyglow are spatially dependent and should therefore be assessed per region. Including the wavelength of the lamp type of the streetlight and including other objects such as vegetation are seen as limitations in this research and could extent this model by doing further research.

This thesis examines the production of an alternative liquid hydrocarbon fuel, namely CO2-methanol, produced utilising DAC, CO2 electrolysis, H2O electrolysis and thermo-catalytic synthesis. The reason for such research lies in a persistent growth in global energy demand, a significant share of which comes from liquid fuels, in the present context of global climate change.
We answer the main research question ‘What is the comparative environmental performance of DAC methanol, natural gas methanol and biomethanol?’ by meeting three research objectives. The first objective provides a two-level analysis of the mass and energy flows within the system and opens the black-box process of the DAC. The second objective leads to undertaking a life cycle assessment of CO2-methanol. Last, the third objective evaluates the suitability of LCA for the environmental assessment of realistic industrial processes.
The results of objective one show that mass and energy balances on the DAC process contain inaccuracies and help to identify unknowns in the remaining parts of the CO2-methanol production. The second objective illustrates that the CO2-methanol performs better than fossil methanol and biomethanol in terms of climate change impact and land use. Additionally, CO2-methanol causes a lower extent of environmental impact on human toxicity (non-carcinogenics) and resource depletion (water) in comparison with biomethanol, however, scores worse on these impact categories when compared with fossil methanol. The environmental performance of CO2-methanol inferior compared to both biomethanol and fossil methanol in terms of freshwater ecotoxicity, human toxicity (carcinogenics) and resource depletion (mineral, fossils, and renewables). Finally, the third objective points to imperfect LCA software available, not sufficient to model realistic industrial processes.