The research is conducted with the case of Shell Netherlands Refinery (SNR), which has already implemented certain NOx reduction measures such as steam injection in gas turbines and Low NOx Burners in furnaces. The decisions to implement these technologies were primarily based on the level of NOx emissions and financial considerations. This thesis aims to support decision-makers by providing a comprehensive comparison of multiple NOx abatement systems based on multiple criteria. SNR has various emission sources for NOx, such as burners in furnaces with the emission point being the stack. Each emission point and NOx source within SNR has its own technical limitations and possibilities, which have been carefully assessed to determine the appropriate NOx abatement systems for each emission point. The Multi-Criteria Decision Analysis (MCDA) approach was employed to answer the above research question. MCDA is a structured approach that evaluates and compares different options or alternatives based on a set of criteria. It enables decision-makers to make informed and objective decisions by considering multiple criteria and weighting their relative importance. The study concludes that combustion-based systems, specifically ULNB for furnace burners and (U)DLN burners for gas turbines, are more advantageous than end-of-pipe systems for NOx reduction in SNR. However, in cases where combustion-based technologies are not technically feasible, the integration of end-of-pipe systems is necessary. In such scenarios, the ClO2 wet scrubber is recommended due to its high final utility score. SCR, SNCR, and LOTOX technologies are generally not advised due to their lower final utility scores but SCR or LOTOX could be viable when high NOx emission reductions are required (>90%). According to outcomes of MAUT, the ULNB was identified as a particularly effective NOx abatement technology, showcasing a consistently high final utility score at numerous emission points, specifically O, P, Q, N, L, I, J, E, M, F, D, B, and H. in contrast, at emission points R, A, E, G, K, S, and W, the most efficient solution was found to be the ClO2-based wet scrubber system, which achieved the highest final utility score. For the final emission points, namely T, U, and V, the (U)DLN burners scored the highest final utility score, thereby earning the recommendation as the preferred NOx abatement technology for these emission points. However, this study had its limitations. The cost analysis conducted was somewhat superficial. A more in-depth exploration of the CAPEX and OPEX, coupled with the use of complexity factors per emission point, could refine the MCDA outcomes. It is recommended that future studies integrate Cost-Benefit Analysis (CBA) into the MCDA for a more rigorous examination. Another constraint was the limited scope and quality of data used. It is recommended that subsequent research take a more rigorous approach to data collection, including engaging factories that have already implemented NOx abatement systems. Such an approach could yield a more comprehensive dataset, enhancing the reliability of MCDA outcomes.

Power-to-methanol (PtM) technologies have a potential to store excess renewable energy in methanol molecules. However, there is a lack of understanding about the role of these technologies in the course of energy transition. In this research, the influence of PtM technologies on power grid’s reliability and CO2 reduction are studied. An agent-based model is developed in order to explore possible future scenarios created by deployment of PtM technologies, in case green methanol is primarily supplied to the shipping sector as an alternative low-carbon fuel. The model outcomes are explored using two sets of experiments representing two hypothetical cases: "flexible grid" experiments in which the power grid is assumed to have several flexibility options, and "low flexibility" grid that the grid cannot easily adapt to high levels of renewable power production. The results show that deployment of PtM technologies can help with absorbing excess renewable energy and improving the reliability of the power grid. However, PtM alone is not sufficient to keep the grid reliable. PtM is shown to be successful in enabling high levels of CO2 reduction. The results obtained in this research can be used as the starting point to open up a discussion between system operator and policy makers in order to define a proper support plan for PtM or other Power-to-X (PtX) options.

As of 2016, governments globally adopted the task to achieve social, economic and environmental sustainability by committing to the targets from the UN Sustainable Development Goals (SDGs). The SDGs incorporate a set of 17 goals and 169 targets accompanied with more than 200 indicators that can guide towards achieving sustainable development by 2030. Sustainable development and human wellbeing fundamentally rest on the capacity of the biosphere to sustain us. In other words, the economy or society related SDGs can only be reached if the biosphere related SDGs, in which they are embedded, are respected. To ensure the achievement of all SDGs, the environmental impact as a result of human activity needs to be reduced to safe levels. Doing so requires quantification of both impacts and safe operating spaces in the environmental domain. However, from the SDG framework it does not become clear what safe operating spaces are because for many of the environmental issues addressed, quantitative targets based on ecological boundaries are lacking. Life-Cycle Assessment (LCA) is a method that enables holistic analysis of the environmental impact of product-systems by analyzing the impacts over the complete life cycle. Yet, as a comparative method it can only identify the most sustainable product system relative other alternative product-systems. In contrast, there have been developments to develop Absolute Life Cycle Assessment (ALCA), in which the environmental impact of a product-system is compared against a benchmark based on the earth’s ecological carrying capacity, in order to define if the system is absolutely sustainable. Such a benchmark is obtained by allocating a share of the environmental carrying capacity to the product system, using a specific allocation principle. The most recognized expression of environmental carrying capacity has been provided by the planetary boundary (PB) framework, offering a set of quantitative biophysical limits for nine critical earth system processes (ESP). The functioning of these ESPs is critical to keep the earth in its stable Holocene state, which is required for anthropogenic prosperity. Using the LCA method to quantify impacts, and the PB framework to provide quantitative ecological boundaries, ALCA could be useful to identify absolutely sustainable product-systems and support contributions from product-systems towards environmental SDG targets. Yet, an overview showing the availability of different ALCA methods and their applicability at the product level is lacking. Therefore, this master thesis provides a systematic literature review of ALCA methods and applications, that use the planetary boundary (PB) framework as an implementation of carrying capacity. The main research question is formulated as: To what extent is absolute life cycle assessment possible and does it enable a comparison of environmental impact against product-level benchmarks based on the PB-framework, to support the identification of absolute sustainable products contributing to the UN SDGs? With a database search on Web of Science (WoS) and a snowballing approach, possibly relevant publications were identified. Afterwards, 14 key publications were selected that entail either an ALCA method or application. The review was conducted with criteria primarily based on an absolute environmental sustainability assessment (AESA) framework identified from literature. The criteria cover aspects related to LCA, the PB framework and allocation approaches needed to obtain benchmarks at the product-level. The results showed that there are 5 dominant methods, and 9 applications of these methods. Only one of these methods includes a direct comparison of impact against a benchmark specifically allocated to the assessed product-system. Therefore, we concluded that only one method can truly be considered as an ALCA method that is also potentially usable in the context of SDGs. However, even claims of absolute sustainability that are made using this method are not fully conceptually consistent because a comparison is made between an annual benchmark (derived from the PB framework) and LCA impacts that are in reality exerted over many years. Other methods were considered usable for different purposes. Some methods only facilitate a comparison of impact against a per-capita benchmark, representing the occupation of an individual’s environmental budget by the product-system. These methods are rather usable for identifying sustainable consumption patterns. Some methods only enable the determination of impact reduction targets against which future impact reductions might be compared. Others do not involve any form of absolute sustainability comparison and are rather usable in conventional comparative LCA. We provided a terminology proposition for PB related concepts because there seemed to be inconsistencies across publications regarding the use of PB-related concepts and their terminology. Also, there were inconsistencies in the terminology for different allocation principles. We stated that all allocation principles could be classified in three main categories. Yet, further research is recommended to find common ground on the choice for specific allocation principles to obtain benchmarks for product-systems. Also, we recommend further research to focus on getting insights in linkages between LCA impact categories, PB’s and SDGs and combining these insights with the knowledge on ALCA methods that has been provided in this thesis. Such a combination would be the next step to find the potential of ALCA methods for supporting contributions from product-systems towards environmental SDG(-target)s.

As the energy transition evolves, more fossil-driven base-load generation is being replaced with intermittent renewable energy sources. Peak power plants will continue to play a crucial role in future renewable energy systems to complement renewable energy supply. The focus of this thesis is on alternative fuels that can be utilized in conventional gas turbines. Several alternatives fuels exist, such as hydrogen, methanol and bio-fuels, and each alternative fuel has different technical, economic, social and environmental implications for the energy system and the society as a whole. Decision makers across the energy sector face difficult trade-offs between quantitative and qualitative criteria when selecting and alternative technology to invest in. This paper applies the analytical hierarchy process (AHP) to select an alternative fuel for a peak power plant in Rotterdam. The fuels analysed are methanol and hydrogen, and are ranked according to nine sub-criteria. Two contributions are proposed to improve the AHP method. Firstly, incorporating a technology readiness level indicator to quantify the technological maturity. Secondly, multiple perspectives are incorporated from key stakeholders in the criteria weighting. A sensitivity analysis is then performed on the most relevant criteria.

Heavy-duty road transport needs to make a transition to become climate neutral in 2050. Not considering the negative impact on the environment, road transport remains a competitive way of transportation in the hinterland of maritime ports. Policymakers and strategists of the Port Authority have a lack of knowledge to decarbonize heavy-duty transportation in the hinterland, without deteriorating the competitive position of a maritime port as a transit node. Various studies are made about the transition in the heavy-duty road transport segment. However, a social cost-benefit analysis that assesses social-economic welfare effects of energy carriers to decarbonize heavy-duty road transport in the hinterland of maritime ports remains unaddressed in the literature. This resulted in the following main research question: What is the socio-economic feasibility of strategies for decarbonization of heavy-duty road freight transport in the hinterland of maritime ports towards 2050? In the literature review promising energy carriers and technologies to decarbonize heavy-duty freight were: battery electric vehicles that drive on renewable electricity, a catenary electric road system that supplies more direct electricity, fuel cell electric vehicles that drive on green hydrogen and conventional trucks that use e-diesel. Considering the availability and the total cost of ownership of these energy carriers and technologies, strategies are developed in which the usage is mandated or stimulated by subsidies. The strategies are compared with the continuation of diesel (the zero-alternative) in a social cost-benefit analysis. The costs and the benefits included are the direct, indirect effects and the societal costs from a tank-to-wheel scope and external effects from a well-to-wheel scope in order to ensure that the emissions do not shift to another part of the chain. The results show that at the current CO2-valuation, all proposed strategies are not welfare enhancing and have severe losses of tax on fossil fuels. However, at an increased CO2-valuation of 500 euro per ton emitted CO2, the strategy in which battery electric vehicles are stimulated by subsidy would be feasible from socio-economic perspective. The social cost-benefit analysis provides insights for infrastructure investments in port areas.

Energy storage systems can play a vital role in the implementation of a sustainable energy grid by allowing the wide scale implementation of fluctuating renewable energy sources like wind and solar. Therefore it is expected that in the coming years, the total amount of energy storage systems will drastically increase. Analysing the sustainability of these storage systems before widespread implementation is therefore of great importance. In this thesis such a life cycle assessment has been conducted to assess the environmental sustainability of one type of energy storage system: the Organic Redox Flow Battery produced by the Baliht research group.

Low-grade heat sources are abundant on earth but are majorly untapped due to lower thermodynamic efficiency at low temperatures and cost considerations. A cost-effective technology is needed to convert this energy resource into useful forms of energy. This work aims at optimizing Organic Rankine Cycle (ORC) based heat engine and a cogeneration system developed to produce electricity and refrigeration from a heat source below 100℃, from both thermodynamic and economic point of view. Exergoeconomics, an algebraic thermoeconomic method, was used to analyze and optimize the systems for cost-effectiveness and exergetic efficiency. Also, the prototype of the cogeneration system was experimentally tested. The results exergoeconomic optimization show that the cost-effectiveness of the cogeneration system can be significantly improved by design parameter changes. The experimental results obtained were comparable with the results obtained from theoretical simulations.