The rare-earth elements (REEs) are Europe’s most critical raw-materials group due to the high supply dependency on the Chinese REEs near-monopoly. The NdFeB permanent magnet in EOL hard disk drivers (HDDs) is an actual source of REEs. However, REEs recycling routes are still under development. Hydrometallurgical routes are attractive because they are versatile, but concerns arise regarding their chemical consumption and the implication to the environment. An ex-ante environmental analysis supports the launch and consolidation of the route in an environmentally sound manner. This work aims to identify the environmental hotspots of a theoretical hydrometallurgical recycling route for REEs, which uses acetic acid for leaching and oxalic acid for precipitation. The route also allows chemical recycling through a loop within it. The ultimate goal is to draw recommendations toward improving the environmental profile of the technology before it gets implemented. The evaluation is carried using the Life Cycle Assessment (LCA) methodology according to a dedicated framework for ex-ante analysis, including upscaling. The analysis highlights as hotspots the oxalic acid in the precipitation stage and the direct dust emissions and its treatment in the fragmentation of HDDs. Moreover, results indicate that acetic acid regeneration within the system is more burdensome than use the chemical produced from raw materials. The premature assessment also indicates that the environmental profile of the emerging technology is potentially inferior to the established primary production. A limitation of the model arises from the economic allocation for multifunctional processes due to the approach developed to stipulate the price of some co-products. Overall, the uncertainties carried with the ex-ante LCA prevent any assertive declaration regarding the recycling route’s environmental performance. However, the exercise contributes to the problem-solution space. It gives directions to the next steps: better data collection for the RE recovery phase, less dust production in the fragmentation phase, other means for precipitation of REEs, and variation in the leaching solid-liquid ratio.

The building and civil engineering sector is the most polluting sector in the Netherlands. Therefore, there is an increasing need for circular and sustainable products and processes. High demand for raw materials and high environmental pressure of this sector could be reduced by implementing the Circular Economy (CE) principles in the public procurement, which is called circular public procurement (CPP). There are different ways to circular public procurement (CPP), among which is the implementation of new business concepts such as Product-Service System (PSS). An example of a business concept that is relatively new in the Dutch infrastructure sector, is the concept of infrastructure-as-a-service, which is a type of PSS. Even though some of CE principles are incorporated in PSS, PSS does not always lead to higher circularity or environmental improvements. Therefore, in this study, the following research question is answered: Does PSS lead to a higher circularity and lower environmental pressure when implemented in the municipal procuring process of a slow traffic road? The research question was answered by performing semi-structured interviews with the experts from the field, by providing the first comparative LCA of a traditional road and its product-service alternatives, and by calculating and comparing the Material Circularity Indicator (MCI) of each alternative.

The scope of this study considers the upper layer of the road and the following life cycle stages: extraction of raw materials, transport of raw materials, production and transport of road components, use, maintenance, replacement, transport of waste and other released material, recycling and waste treatment. The function studied was the availability of 11,200 m2 of paving brick slow traffic road surface for 40 years’.

Based on the set scenarios, the LCA results showed that product-service alternatives do have significant environmental benefits over the reference system. The product-service scenarios were based on the two environmental strategies that were mentioned in both the interviews and in literature: i) extending the useful lifetime of the product and ii) reducing waste and optimizing end-of-life treatment. Relative to the baseline scenario, the biggest environmental gains and the biggest increase in circularity can be achieved when the currently downcycled material is reused or repurposed instead of recycled. By reusing all residual paving material at the end of its use, the CO2-eq emissions can be reduced by 77%, and circularity can be increased by 8%. The other two assessed improvements of the use and end-of-life phase were the reduction of breaking percentage and the increased utility of concrete components through a material passport. The last initiative led to 3% higher circularity but it did not lead to significant environmental improvements while the reduction of breaking percentage did lead to improved environmental impacts but it did not lead to a change in circularity. When combining all three initiatives, which was done in the product-service++ scenario, CO2-eq emissions can be reduced by 95%, freshwater aquatic ecotoxicity by 98% and stratospheric ozone depletion by 90%, relative to the baseline scenario. In addition, this study identifies the supply of road components that includes extraction of raw materials, production and transport as the hotspot of each alternative, which indicates the importance of material reuse. Furthermore, over the whole life cycle of each alternative, electricity was identified as the biggest contributor to the characterization results due to the high share of fossil fuels in its generation.

Even though the possible product-service scenarios lead to improved environmental performance and circularity, the results from the interviews indicated that the concept of infrastructure-as-a-service is still in its infancy and that several issues need to be addressed before it can be implemented on a large scale. The issues that need to be addressed are the separation of economic and legal ownership by law, additional burden in contract management and contractual risk inclusion. Furthermore, the concept of infrastructure-as-a-service seemed to fit more to infrastructural objects that are located in the countryside because an object in the countryside has less direct connections to other infrastructure meaning the influences from the surroundings are minimized, which poses less risk to the provision of the functional unit. Before the above-mentioned issues are solved, infrastructure-as-a-service is not recommendable. Instead, municipalities as the owner of an infrastructure should take their responsibility to properly reuse paving material.

Resilience has been gaining importance as a key element that prepares the supply chains to respond after disruptions. In this thesis, the material supply chain resilience framework is used to study the supply chain of tin before and during the disruption caused by the COVID-19 pandemic. Tin is a small-scale market compared to other major metals but its importance is increasing thanks to its possible applications in the next-generation lithium-ion batteries, fundamental for the energy transition. Besides, Tin is one of the main elements used in the semiconductor industry which is at the centre of the trade war between the US and China. In order to increase its potential and be used in “next-gen” batteries, tin supply chains must show resilience. Using qualitative and quantitative data and modelling, this paper aimed to explore the resilience of the supply chain of tin. The research showed that Tin demonstrated considerable resilience during the COVID-19 disruptions ,thanks to the semiconductors and Chinese demand, both of which increased during the second quarter of 2020. Currently, almost half of tin production goes to solders, which explains the high dependency between the tin market and the semiconductor market. China is the biggest producer and consumer of tin, which makes the demand for tin dependent on Chinese demand. The analysis of the resilience mechanisms showed stockpiling and diversity of supply are integrated into the supply chain but their contribution to resilience remain low. Substitution could not be considered a resilience mechanism due to the lack of substitutes for tin solders. The resilience mechanisms would gain importance in the future of tin if it would be used in new technologies. The model presented in this thesis estimates the amount of tin that will be used by 2030. With this in mind, recycling of tin must be increased to support the future demand. Consequently, Governments and companies must invest in technologies in order to increase the recycling of E-waste. Lastly, the development of the relations between the US and China will also interest the tin supply chain. In this regard, three different sub scenarios are analysed: complete decoupling, partial decoupling, and no-decoupling.
 

Acceleration of the energy transition requires increased mining of materials. An important material for the energy transition is nickel, used in the stainless steel required for all energy infrastructure and an important component for both stationary batteries and batteries used in electric vehicles. Previous research has been done on the global nickel requirements for the energy transition at a high level of aggregation. In this thesis, exploratory system dynamics modelling and analysis was used to assess the resilience of the nickel supply chain and its nexus with the energy system at the level of individual mines. The development of the global nickel supply chain, and its energy requirements and greenhouse gas emissions, was modelled and explored between 2015 and 2060 under different disruption scenarios, sustainability policies and uncertainties. A nickel demand of 6 - 18 million tonnes per year is projected by 2060 for the BAU scenario, with projections up to 38 million tonnes per year in the scenarios that aim to limit global temperature increase to 1.5 °C. The main contributors to this large demand are electric vehicle batteries. The nickel system is conditionally resilient to the energy transition, given sufficient exploration and annual capacity increase. To increase the resilience of the nickel system, policies that support innovation in battery material composition and lifetime and good end of life waste management of batteries can play an important role. Modelling the nickel supply chain at mine level leads to different behaviour compared to previous research where mines were aggregated. Insights obtained from the detailed modelling in this thesis include a higher demand than previously projected; the possibility of the average ore grade increasing over time as mines with lower ore grades are decommissioned; average final energy requirements that can decrease, increase or increase rapidly depending on a varying average ore grade, a varying composition of processing methods and a varying composition of by-products; average energy costs that differ depending on the projected electricity mix in the countries containing deposits; and a reduction in end of life nickel recycling rate for most scenarios due to an increasing share of batteries. The most important contribution of this thesis is not in the data and assumptions, but in the model itself, which can be adapted and refined in further research, where more stakeholder input is included, to make the outcomes more robust and useful for decision making. Other important avenues for further research include determining how much exploration is possible and how quickly mining capacity can be increased.

The Dutch government aims to become fully circular in 2050 and to reduce the virgin material demand by 50% in 2030 (Rijksoverheid, 2016). For a country that has relied on a linear economy for centuries, this will prove to be a major challenge (Circle Economy, 2020; Rijksoverheid, 2016). Simultaneously, due to urbanization, the Dutch government intends to build one million dwellings between 2016 and 2030 (Ministerie van Binnenlandse Zaken, 2020). These two goals conflict because the first one aims to reduce material demand, whereas the second indirectly increases it. So far no study has paid attention to the impact of different circular construction solutions on the abiotic material demand. This is the gap that this thesis aims to fill, using the city of Leiden as a use case.
To help solve this problem, three steps were taken: 1) create a baseline of the total material demand for the residential sector, starting from the assumption that we continue to build in a linear way; 2) examine the views on circular solutions among experts; and 3) quantify the impact of certain circular solutions on the baseline in order to assess whether the goals defined by the government can be reached. The main aim of this thesis is to create a model that enables us to quantify the impact of five solutions in six different scenarios. In the first scenario the research on the potential of urban mining materials from Verhagen et al. (2020) is expanded and followed up by a second scenario in which the loadbearing structure was replaced by a (partly) wooden alternative. Thirdly, other elements of the building (e.g. facade and interior walls) were replaced by a biobased variant. In the fourth scenario the floor area of the apartments is decreased and in the fifth scenario the basements commonly built under high-rise apartment buildings are removed, whereas in the sixth, and last, scenario the first five are combined. From the analysis results that the two goals mentioned above are only achievable through a combination of multiple solutions. The total virgin abiotic material demand for an average year between 2020 and 2030 would be around 155,000-tons in the business-as-usual scenario. The biggest impact came from switching the concrete loadbearing structure to a wooden (CLT) alternative, which leads to a reduction of 46% of the virgin abiotic material demand. The second largest impact resulted from converting the low- and high-rise apartments into micro-apartments in combination with downsizing the single-family dwelling size by a quarter, which leads to a reduction of 27% of the virgin abiotic material demand. Similar to this solution is excluding basements for parking under high-rise apartment buildings, which gives a 24% reduction. This is followed by the Urban Mining scenario, in which the released circular demolition waste is recycled/reused. This scenario had an impact of 19% on the total virgin abiotic material demand but is less difficult to implement compared to downsizing living space or parking spots. The scenario with the lowest impact was replacing abiotic material in the fit-out of a building, which only yields 7% of the virgin abiotic material demand. All solutions combined the total reduction was 91%, which clearly transcends the absolute goal of 69%. The results of the quantitative part of this thesis were in line with the results from the interviews, where changing the structure was mentioned as “the biggest fish” and changing the fit-out “rumbling in the margins”.

In the Netherlands, almost half of the energy supplied to households is used for space heating. Since natural gas supplies heating fuel to almost 95% of residential buildings Dutch municipalities have to investigate the possibilities of diversifying their heating infrastructure in order to comply with government environmental goals. Possible heating alternatives included in this study are; biogas, district heating and all-electric. In this thesis, a geospatial model was constructed to analyse the energy demand of the city of Leiden and its energy infrastructure. By combining various governmental datasets in Python and GeoPandas an analysis on the city scale is possible. The main focus of the thesis is material demand for each heating alternative and the associated environmental impact of those materials. The current heating system of natural gas scores lowest on total material demand and embedded carbon. Of the investigated alternatives the district heating scenario has most materials embedded into the infrastructure and also the highest carbon footprint. The all-electric scenario completely replaces heating infrastructure by only utilising electricity for heating. This results in a significant system change with average material consumption. However, the all-electric scenario scores highest for demand in REE’s. A combination of heat pumps and biogas resulted in the lowest material consumption of the researched alternatives. This scenario combines the relatively simple conversion to biogas for older houses with the most efficient heating utilising heat pumps for new houses. The major drawback for this scenario would be the sourcing of biomass required for biogas production.
In terms of embedded CO2 the sustainable heating alternatives proposed in this thesis score higher than the current system. However, the embedded carbon of the building materials would be compensated for in the first year if use-phase emissions are taken into account. The emissions associated with the construction of the supporting energy infrastructure were found to be significantly smaller compared to the use-phase emissions. Together with factors such as heat source availability, investment costs and social acceptance of the heating alternatives municipalities have to decide which heating alternative has its preference.

In the Netherlands, many cities aim to promote cycling as a solution for sustainable mobility. However, the bicycle parking shortage is common. The popularity of ‘car-free city’ concept provides the opportunity to solve the problem by replacing car parking spaces to bicycle parking spaces. This study used a GIS-based location-allocation method to optimally locate the bicycle parking facility in car parking spaces. Through a case study in the city centre of Leiden, the results show with the small amount of car parking spaces, bicycle parking shortage can be largely relieved.

Electric Vehicles are shaping the clean energy goals and have become the poster for climate change and the energy transition. Its not only cars that is making an impact but more importantly, micro-electric vehicles spearheading first/last mile solutions. These vehicles reduce net emissions on the environment. This market needs further literature and information to integrate and have better solutions. This thesis explored the ecosystem surrounding the micro-mobility market just to underpin the lack of literature available and the need for further research on this topic. All stakeholders were studied, vehicles were investigated, business cases were discussed and environmental impacts were approximated. The policy side to this market is very crucial to its growth and this has been highlighted in this thesis. The safety impacts indicate that the market has taken a huge hit in many countries the necessity for regulatory structure has become more integral. The vehicles will get better with time and safer, and if implemented in cleaner ways, can have a huge impact on short distance mobility space. The market is poised for growth but in the Netherlands there are many roadblocks and these need further exploration. The study concluded that these vehicles are bound to stay and grow and implementation depends on regulatory climate, enforcement of safety standards, technology standards and infrastructure. Technology trends also project better vehicles in the future. Innovation in types of implementation of shared micro-mobility is still a big question. When these factors are addressed, micro-electric mobility can grow and have a huge impact in the creation of Smart Cities and better, cleaner, more efficient mobility options.

This thesis researches the possibilities of changing end-of-life strategies for leftover paint chain in Amsterdam using a sustainable business model framework. It compares three scenarios by evaluating their economic, environmental and social impact. The existing business models are mainly focused on the economic value. The purpose of this thesis is to develop a new practical sustainable business model that encompasses sustainable elements. The aim is to provide a guidance for waste management studies to quantify their research and make practical decisions regarding the best end-of-life strategies. The research aspires to integrate sustainability in the company business model as an essential part. Hopefully, this will lead to new sustainable business models in the future that can be applied.