Over the past few decades, sustainable development has become one of society's most important challenges. In an effort to become sustainable, many companies experience an increasing need to measure, manage and improve the negative economic, environmental and social impacts caused by their organizational behavior along corporate supply chains and product life cycles. Sustainability performance assessment methods are a means for business decision-makers to meet such needs. While sustainability performance assessment methods for economic and environmental dimensions are well-developed, the social dimension of sustainability is lacking in that regard. Social sustainability entails issues such as equity and human rights of company stakeholders such as employees, customers, local community members, value chain actors and society. There is an increasing concern to incorporate social sustainability by businesses so as to become sustainable in all three dimensions; however, an empirical tool is needed to for measuring the social impacts of the company operations and making improvements. The Social Life Cycle Assessment (S-LCA) tool was developed for the assessment of the social dimension of sustainability in a meaningful way for application in the business world. United Nations Environment Program (UNEP) and the Society for Environmental Toxicologists and Chemists (SETAC) developed S-LCA Guidelines and Methodological Sheets in 2009 and 2013, respectively, for assessing the social impacts of products and services across the life cycle. The UNEP/SETAC S-LCA methodological framework has been considered the “landmark in the field” of social sustainability assessment because it provides a view of the value chain, an aspect lacking in other social sustainability assessment tools. Even with recent increasing publications by S-LCA practitioners, however, S-LCA is still at an early stage of research and the UNEP/SETAC Guidelines leave a lot of room for interpretation. Thus, it is urged to conduct more research in the field of S-LCA, and a main way to contribute to its further development is through case studies. This research aims to contribute in this way by developing and applying a S-LCA methodology to a case study of the ZERO BRINE project in the Netherlands. The ZERO BRINE project is a European Union-funded partnership that works on zero liquid discharge technology for water, salt and magnesium recovery from brine effluents in the chemical process industry. The main objective of this thesis is to assess the social sustainability performances of the organizations in the ZERO BRINE system in the Netherlands using the UNEP/SETAC S-LCA framework as a reference, so as to determine the social impacts associated with the project as well as to contribute to the further development of the S-LCA methodology. Despite some limitations, in general, the approach proposed in this thesis succeeds in providing a profile of social sustainability which highlights the social hotspot areas that need improvements along the value chain. The results of the case study show the potential social hotspots in the ZERO BRINE chain, which should be considered when implementing the ZERO BRINE project. Personalized recommendations are offered per organization on how those hotspots can be improved. In this way, the advice may be valuable for members of management of the organizations wishing to increase the social sustainability of the business. In particular, the ZERO BRINE system may show a more positive social sustainability outcome if the recommendations of this thesis are implemented strategically.

Increasing ship emissions are of big concern because they contribute to the effects of climate change and have an impact on the local and regional environment. Due to these concerns, stricter regulations are enforced upon the shipping sector by the International Maritime Organisation and the European Union. However, since new regulations are enforced, stakeholders have been slow to react. A key reason why investment decisions are not taking place is that of uncertainty in regulations and policy. Besides, the availability of bunker infrastructure in ports is key to the development of alternative fuels. The objective of this study is to obtain insight into what possible future scenarios of the deployment of alternative fuels for the short sea shipping might arise and to provide insight into the effects of collaborative port strategies on the emergence of alternative fuels European maritime short sea sector taking into account regulatory and technological uncertainties. By means of an agent-based modelling approach and exploratory modelling and analysis approach, the influence of these uncertainties and policies is addressed. This enables to obtain a better understanding of where the system might go. The findings of this study show the effect of regulation enforcement and the need for a well-developed methanol bunker infrastructure across Europe to enable the transition to alternative fuels.

The Dutch container glass industry is an energy- and capital-intensive industry which accounts for about 350 kt of carbon dioxide (CO2) emissions on an annual basis. The fluctuating energy prices during the past decades as well as the implementation of the European Emission trading scheme (ETS) are pushing towards the deep decarbonisation of container glass-making activities. However the uncertainty which surrounds the transition strategies hinders the decarbonisation efforts, leading investment decisions in CO2-reducing technologies to postponement. In this study, a set of optimally robust-performing policy options is identified for the effective decarbonisation of the container glass industry by 2050. By conducting techno-economic analysis on the processes of Dutch production sites, alternative technology options and their combinations are compared on the basis of their technical and financial feasibility. The robustness of decarbonisation strategies is determined on the basis of carbon emissions, energy consumption, product cost and return of investment and assessed under a wide spectrum of potential future events using a many-objective robust decision making technique. The study concludes on the importance of using alternative fuels (i.e. biomethane, electricity and syngas) as well as the coupling of waste heat recovery options with innovative furnaces for improving the melting activity. Further development of breakthrough technologies is necessary to achieve greater carbon emissions reduction, which will be supported by a sound regulatory framework for technology deployment. The study can be leveraged by industry stakeholders and policymakers on the future of the container glass sector and the industry in a broader sense in a competitive low-carbon economy.

The Netherlands aims to accelerate the energy transition. Accordingly, ambitious targets have been set for the industrial sector. This will require additional investments in the Dutch industry which is expected to reduce the CO2 emissions at limited costs in comparison with other sectors. However, the ambition to reduce the emissions can create a risk of loss of activity and jobs if the industrial businesses prospects are not ensured. Power-to-heat technology provides an opportunity to the industry to reduce the emissions for heating processes. This technology can be implemented in hybrid configurations to ensure the electrification of heat. Hybrid configurations are characterised by their ability to switch between natural gas and electricity which could cost-effectively reduce the emissions consuming electricity at low prices. In this research, a techno-economic evaluation of hybrid boiler systems is performed to analyse the potential of this technology to cost-effectively reduce the CO2 emissions for steam generation in a production process, in 2030. To this end, the operation of hybrid boiler systems was simulated and assessed. The performance of hybrid configurations was compared to alternative options. Finally, the hybrid systems were analysed under different scenarios for 2030. The results for the case study presented, showed that hybrid configurations saved operation costs and reduced the direct CO2 emissions by almost 20%. Therefore, the hybrid boiler could cost-effectively reduce the emissions. However the potential benefits of hybrid boilers are subjected to variation of electricity, natural gas and CO2 prices.

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.

Negative emission technologies aim to remove historic CO2 from the atmosphere. Bioenergy with carbon capture and storage (BECCS) is regarded as a possible negative emission technology. This thesis aims to study the technological and economic feasibility of implementing BECCS in the cement industry. Four different types of biomass - rice husk pellets, wood pellets, sewage sludge, and municipal solid waste were chosen to substitute 30% of the coal in a model of a European cement plant. With an emphasis on retrofitting, three CO2 capture technologies, absorption using monoethanol amine (MEA), calcium looping (CaL) based capture, and oxyfuel combustion capture were chosen. This thesis compares the techno-economic performance of the BECCS technologies in a cement plant using the key performance indicators (KPIs) of specific primary energy consumption per CO2 avoided (SPECCA), cement production costs and costs of CO2 avoided. Mass balance results and estimates of capital and operating expenses were used to calculate the KPIs. The parameters for each biomass-CO2 capture combination are compared to each other and compared to the reference value of a cement plant which uses 100% coal without CCS. The results were subjected to sensitivity analysis. CO2 accounting was performed for a defined boundary to estimate the carbon footprint of the BECCS technologies. The BECCS technologies studied have a lower rate of cement production as a result of co-firing biomass in existing boilers. This can be attributed to the low calorific value of biomass. Of the three CO2 capture technologies, oxyfuel combustion capture is the least energy consuming option (1.8 MJ/tCO2, with wood pellets) and the highest range of SPECCA is visible in the case of MEA (8.6 MJ/tCO2, with municipal solid waste). The cement production costs increase by 42 to 89% compared to the costs without CO2 capture. The cost of CO2 avoided is between 45 €/tCO2 (wood pellets with oxyfuel) to a higher range of 96 €/tCO2 (sewage sludge with MEA). The variation in costs is significantly affected by the type of biomass used. CaL technology has a moderate performance in energy consumption and costs. SPECCA obtained for CaL process is in the range of 4.1 to 4.4 MJ/tCO2 and the cost of CO2 avoided is in the range of 57 to 74 €/tCO2. CaL also entails the highest CO2 capture rates, in comparison with MEA and oxyfuel technologies. In terms of total CO2 emissions avoided, CaL based CO2 capture gives the highest CO2 avoided for the system boundary defined. Therefore, when the CO2 removed from the atmosphere through the growth of biomass is included, the net CO2 emissions are the least for CaL capture technology. The reason is the additional thermal energy requirements for the retrofitted CaL process units, which are met with 100% biomass. Although theoretically, a net negative value of CO2 emissions was visible in the case of CaL, it must be noted that upstream process emissions are not included. But in practice, it is still unclear as to whether negative emissions are attainable with the information at hand.

This research provides insight into the implementation of CCS in industrial production from a consumer perspective (i.e., the cost impact on the final product). The impact of implementing CCS in two different industries (e.g., cement and steel) to produce a final product is analyzed. Also, this research provides insight into CCS implementation in industries with high consumption products. It can be concluded that implementing CCS in industrial processes offers a solution to decarbonize industrial processes with a small impact on the final product cost.

Life cycle assessment (LCA) has been the primary tool for the quantification and comparison of the environmental impact of product systems. Despite ongoing development of the LCA methodology, uncertainties are often not adequately addressed in LCA research. The large variety of approaches to treat uncertainties and the lack of uniform guidelines prevent a widespread adoption of uncertainty analysis, while its importance is generally acknowledged. Especially in the agricultural sector, where LCA is often used as policy support, uncertainties are of great importance. This thesis aims to provide guidelines for practitioners of agricultural LCA in developing countries, as agriculture is often an important sector there. To this end four different method of uncertainty propagation are tested on a case study of sugarcane cultivation methods in Thailand. These methods are compared and evaluated on their suitability for agricultural LCA in developing countries, complemented by an expert survey in a Thai LCA research network. The results show that there is a general lack of knowledge among LCA practitioners on uncertainty analysis, while primary data is often abundant. Also, sampling methods can provide great insight into the output uncertainties, but are also complex and data intensive. Analytical or fuzzy interval methods could be a good alternative when knowledge or resources are lacking. LCA practitioners should be better guided in choosing and performing the most suitable propagation method for their situation. To this end, a decision tree for choosing the most suitable method depending on the user and the type of study closes this thesis.

This thesis researches the influence of various communication channels, considering the psychological aspect of consumers, to the adoption process of residential PV system, using agent-based modeling case study in the Netherlands. Agent-based model is used to explore how PV adoption dynamic behavior emerges as the result of information transfer between individuals on a new technology. Diffusion of innovation theory is used as the basic framework on how the usage of new technology can spread and theory of planned behavior is utilized to get better understanding on consumer's psychological decision making process. Further discussion with a representative of power utility and interviews with 2 PV installers are done to obtain more knowledge on the system. The study shows that mass media has important role in spreading information to speed-up the adoption, more importantly in providing initial knowledge to households that have not had interest on PV yet. The role of information is further shown as there is indication that households' interest tend to increase with more knowledge available on the internet, and at the same time, leads to the increase of adoption rate. A crucial role of communication channel is to draw PV installer together with potential adopter. Finally, the adoption rate is strongly slowed down by household's basic reluctance on new technology and lower income level.

The energy system is a complex socio-technical system, characterised by a multitude of stakeholders, different goals, long-term investments, and large scale sub systems with long lifetimes. The government of the Netherlands aims to support the transition of the energy system of the Netherlands towards a sustainable system by implementing policy measures. Recently, companies have voiced their concerns on the fluctuating effects of policy measures in the Netherlands and have asked for a more long term vision of policy measures. This long term vision can be (partly) provided by analysing the interference in the energy system. Another component of a policy strategy is that to develop and implement a long term policy strategy, multiple governmental organisation have to collaborate. The policy measures are designed by different ministries within the Netherlands. In order to implement the coherent policy strategy, collaboration between these ministries is essential. This research proposes a methodology to identify five types of interference and to analyse the effects of the identified interference on the Dutch energy system. This categorization of interference allows for a discussion on the unavoidable nature of interference. Moreover, it shows which types of interference can prove to be beneficial at certain times. A conceptual theoretical framework for factors that influence interorganizational collaboration between public parties has been constructed based on literature, and is tested and validated within the case study. The research into interorganizational collaboration also includes a focus on the relations between the identified factors. The relations can provide insight into the more complex system view of the factors that influence interorganizational collaboration between public parties. Both researches are based on a view of the world in systems, and for both is searched for links between sub-systems. Finding the link between the technical energy system and the collaborations required in policy making was based on this system perspective. These two topics are invariably linked together. The integrations in the energy system increases the need for collaboration, whereas collaboration can increase (the effectiveness of) the integrations in the energy system.

Reducing carbon emissions in the power generation sector can be done by generating energy from renewable sources such as wind and sun. However these sources alone cannot provide a reliable electricity system and therefore an energy storage system is needed. Power-to-gas is a concept in which surplus renewable electricity is used for the production a gas fuel. The gas can be stored and is used for electricity production when there is a deficit in renewable electricity. When CO2 exhaust gases form reactants for new production of gas, the system has no net CO2 emissions. The gas functions as an energy carrier for electrical energy. Methane could be an interesting gas for large scale energy storage as there is much knowledge about methane transport, storage and combustion and the gas is easier to store than hydrogen. Power-to-gas-to-power conversions come with great electricity losses. Therefore it is interesting to investigate what waste heat streams can be extracted from the process to use for external purposes. The aim of this thesis is to map the input and output energy streams of a power-to-methane-to-power system operating in 2030 to find the efficiency of the system and to see how efficiency could be maximized by using waste heat streams for external purposes. Also, a power-to-methane-to-power system requires a lot of gas storage capacity. Therefore it is useful to estimate the capacity of the gas storage facility to find if the system is technically feasible and to see what gas storage does with the efficiency of the system. Last, since the aim is to reduce carbon emissions the (small) CO2 emissions of the system are determined and analyzed. The system is scaled up to a scenario in which it provides a fully renewable electricity grid in the year 2050, to explore the feasibility in terms of carbon emissions and required gas storage capacity. The system is also compared to a power-to-hydrogen-to-power system to find the most feasible solution. The round trip energy efficiency of the system in 2030 is 88.0%, which is the sum of an electrical efficiency of 30.0% and a thermal efficiency of 57.1% The total energy efficiency can only be achieved when streams modeled as usable heat output streams can actually be used. This depends highly on the location of the system. The carbons emissions of a system with a 44MW output in 2030 are 56.3kt and the required gas storage capacity is 5.09 x 10^5 m3 of underground salt caverns. When scaling up the system to provide a fully renewable electricity grid, the total gas storage capacity is 9.34 x 10^7 m3, which is 5.5% of the total potential salt cavern volume in the Netherlands. The carbon emissions are 2.78 kt/y, which is 0.0056% of the current annual carbon emissions caused by the Dutch power generation sector. Compared to a hydrogen system the methane system performs worse in term of electrical efficiency, gas storage capacity and carbon emissions.

In this thesis the goal is to determine the mitigation potential, below 100$ per ton of CO2e, of nine climate mitigation measures in 2030 for the G20 and world regions across six sectors. The mitigation potentials for these measures was determined using a bottom-up approach utilizing recent literature, and where needed by up-scaling found results along assumed variables. The determined mitigation potentials are compared with the emissions gaps between a current policy scenario and scenarios limiting temperature rise below 1.5 and 2 degrees compared to pre-industrial levels. These emission gaps are estimated to be 18-22 GtCO2e, and 24-27 GtCO2e, respectively. Further, the found mitigation potentials are compared with the nationally determined contributions (NDCs) to the Paris climate accord of the G20 member states. It was found that the global mitigation potential for the nine treated measures in 2030 is 19-27 GtCO2e. Subsequently, it is concluded that the emission gaps can both be closed if the mitigation potentials for the nine measures are realized, and that the NDCsof the G20 countries can be achieved in 2030 by a large margin. Finally, it is concluded that the G20 has a mitigation potential of 14.4-20 GtCO2e in 2030 and thus has a significant share in the envisioned mitigation potential.

As the world grapples with the escalating challenges of climate change, Carbon Capture and Storage (CCS) emerges as a crucial solution, especially for decarbonizing dominant industries such as steel, cement, and petrochemicals. The Intergovernmental Panel of Climate Change (IPCC) and the International Energy Agency (IEA) have highlighted the potential of CCS in addressing the pressing need for large-scale decarbonization. However, the widespread adoption of CCS is hindered by various challenges, including financial, organizational, technical, and governance aspects. Within this context, the research delves into the central question: "How can an evaluation framework combining both project- and policy-related factors provide a better understanding of the deployment of full-chain CCS projects, and how is it developed and implemented?" To address this pivotal question, the study employs a multifaceted methodology. Literature research, semi-structured expert interviews, the Best-Worst Method, and a project maturity table are utilized to derive comprehensive insights. Factors influencing CCS projects are systematically categorized into six groups: political-legal, economic, social, technical, ecological, and organizational. Additionally, the research presents two in-depth case studies, ROAD and Longship, offering a practical lens into the challenges and triumphs of real-world CCS projects. The culmination of the research is a robust evaluation framework that provides a systematic approach to assess various facets of CCS projects. This framework emphasizes critical areas for resource allocation, stakeholder communication, legal clarity, and financial stability. In essence, this research not only addresses its foundational question but also crafts a multifaceted tool that stands to benefit stakeholders, guiding informed decision-making and enhancing the prospects of CCS projects' success and longevity.

In line with the Paris Agreement goals that were signed in 2015 by a total of 195 countries,among which the Netherlands, governments worldwide are formulating plans to reducetheir CO2 emissions. In the Netherlands the Dutch industry accounts for 40% of the total CO2 emissions and therefore decarbonisation of this sector is highly relevant. The Port of Rotterdam is home to a large variety of power plants and chemical companies producing all sorts of essential products, such as fuels, platform chemicals and polymers. Polyvinylchloride (PVC) is one of the polymers produced in the Port and on average 100 ktonne of CO2 is emitted every year during the manufacturing. PVC manufacturing companies have a significant responsibility to reduce their CO2 emissions and explore more environmental-friendly production methods. This research aims to aid in the transition by exploring decarbonisation pathways through which PVC manufacturers in the Netherlands can reduce their direct CO2 emissions.  This study will answer the main research question: How can selected hydrogen and biomass decarbonisation configurations reduce direct CO2emissions in the Dutch PVC industry and how do these perform in a grey-box techno-economicanalysis? To answer the main research question, secondary research questions were formulated, which are systematically answered throughout this study:• What are the main steps of the production of PVC in the Netherlands and which step is the primary source of CO2 emissions?• Which three selected hydrogen and biomass decarbonisation configurations are promising for decarbonisation of the Dutch PVC industry and where do they fit in the PVC production process?• How do the selected hydrogen an biomass decarbonisation configurations compare in a grey-box techno-economic analysis?  This was done by carrying out a literature study on the current PVC production process ofShin-Etsu in the Port of Rotterdam, followed by a Mass Flow (MFA) and Energy Flow Analysis (EFA) which identified the thermal cracking of ethylene dichloride (EDC) to vinylchloride monomer (VCM) as the main source of CO2 emissions in the production process. Next, three decarbonisation configurations were proposed that make use of several renewable energy technologies, such as solid oxide fuel cells (SOFC), solid oxide electrolyser cells (SOEC), electric furnaces (EF) and hydrogen furnaces (HF):• Configuration A: A hydrogen-fed SOFC system with an electric furnace.• Configuration B: A biomass-fed SOFC system with an electric furnace.• Configuration C: A electricity-fed SOEC system with a hydrogen furnace. These configurations were modelled using grey-box modelling and compared in a techno-economic analysis using the following parameters: Net Present Value (NPV), Payback Period (PBP), Technology Readiness Level (TRL) and Energy Efficiency (EE). The main results and conclusions of the study are as follows: • PVC production in the Netherlands can be split in two main production steps: VCM production and PVC polymerisation. It was found that thermal cracking of EDC to VCM during VCM production is the main source of CO2 emissions.• Under the assumption that indirect heating technology will continue to be developedand pilot tested, electric furnaces with a supporting SOFC system could see implementation in the future. The energy efficiency of this configuration was estimated at 51%. This setup has the potential to negate direct CO2 emissions from the traditional cracking furnaces. However, the economic viability of hydrogen fed SOFC systems will be highly dependent on lower hydrogen market prices. In order to avoid shifting CO2 emissions from inside the gate to outside the gate an infrastructure where affordable, green hydrogen is available is key. Close collaboration between all the stakeholders in this supply chain will be important.• Biomass-fed SOFC systems combined with an electric furnace showed a positive NPV due to the lower price of biomass compared to hydrogen. The energy efficiency of this configuration was estimated at 45%. Sufficient availability of biomass in the Netherlands would benefit the potential of biomass-fed SOFC systems in the future, but this is not certain. Furthermore, the debate whether or not the use of biomass is carbon neutral continues as scientists call for caution since burning biomass is instant, while depending on the type of biomass it might take decades before the same amount of CO2 is drawn from the air. Biomass should therefore be used carefully. The future price of electric furnaces are subject to uncertainty and the economic viability of configurations using this technology should be reaccessed once the technology is closer to maturity.• A SOEC system supporting a hydrogen cracking furnace showed the highest NPV and the shortest pay back period of all three configurations. The energy efficiency was estimated at 61% which is the highest of all three configurations. SOEC is reaching high TRL and it is expected that by 2030 1+ MW systems are commercially available. If hydrogen cracking furnaces will also continue to strongly develop in the future, this configuration could be successful. Availability of renewable electricity and storage methods to deal with the intermittent nature of wind and solar are important enablers that could help SOEC systems gain momentum. Access to renewable electricity will also avoid displacement of direct CO2 emissions from the PVC industry to indirect CO2 emissions sources.

Uncertainty has an obstructing role in the decision-making of electrification investments for industrial actors. Future research by analysts is required to explore the potential of electrified industrial systems in their uncertain environments. In order to enable research to uncertainty in electrified industrial systems, the identification and exploration of uncertain factors is required. In this research, a method is proposed to identify and explore uncertain factors in electrified industrial systems. The development of the method is based on literature analyses. The findings in the current work about the conceptualisation, identification and exploration of uncertainty are synthesised with the specific characteristics of industrial environments. This led to the development of the Industrial uncertainty scan. The method was applied to a case-study to discuss its value.

This thesis compares the performance of hypothetical biorefineries in Brazil and Scandinavia that produce biofuel for use in large marine vessels using one of three thermochemical technologies—hydrothermal liquefaction (HTL), fast pyrolysis with hydrodeoxygenation (FP), and gasification with Fischer-Tropsch synthesis (GFT)—and one of ten lignocellulosic residues from forestry and agriculture. The biorefineries were modeled using black-box mass balances for biofuel production and electricity and heat cogeneration. The results of this model, along with local costs factors, were used to estimate the economic performance of biorefineries in each country where each feedstock is available. Estimates of capital expenses, operating expenses, and annual earnings were used to calculate the minimum selling price of the biofuel, which is used as an indicator of economic performance. The environmental performance of each combination was estimated using the indicators of life cycle greenhouse gas emissions, sulfur dioxide emissions, nitrogen oxide emissions, and non-renewable energy use. The economic and environmental indicators for each feedstock-technology-country combination are compared to each other and also compared to reference values for other marine emission-reducing technologies, including liquid natural gas, emission scrubbers, and soy biodiesel. The results are subject to sensitivity analysis to determine the influence of uncertainty of capital costs, feedstock costs, biorefinery scale, biorefinery siting, biorefinery configuration, biofuel yields, biofuel blending, and environmental impact allocation. The biofuels modeled in this study have significantly lower life cycle greenhouse gas and sulfur dioxide emissions and non-renewable energy use than those of heavy fuel oil, but have higher life cycle nitrogen oxide emissions, due to the lower quality of the fuel produced and combusted. Economically, none of the biofuels are competitive with current fossil fuel prices when estimated with the scale and cost factors in this study. The feedstock-technology-country combinations with the lowest minimum biofuel selling price, when considered as a ratio to the current local price of marine gas oil, are the hydrothermal liquefaction of barley straw in Sweden, and the fast pyrolysis of corn stover and rice residues in Brazil. Each of those combinations has a minimum biofuel selling price ratio of 3.2 times that of marine gas oil. Performance trends between technologies and feedstocks are weak, and superior economic performance does not correlate with superior environmental performance.

The capture of carbon dioxide before or after it is emitted has been regarded as a crucial mitigation pathway to prevent the rapidly increasing accumulation of CO2 in the atmosphere. The valorisation of the captured CO2 into value added products such as methanol provides an additional economic incentive to continue developing these technologies. The company Zero Emission Fuels B.V. (ZEF) is currently developing a mass-producible miniature methanol plant that houses a Direct Air Capture and CO2-compression unit, an Alkaline Electrolysis Cell, a Methanol Reactor, and a Distillation unit. Potential benefits of this approach are in the economies of scale of production, and autonomous operation in areas of high solar irradiation due to direct integration with PV systems. To validate the microplant-concept from an environmental perspective, a research project was executed with the goal to establish the environmental profile of the microplant, to identify hotspots for impact mitigation, and to assess the position of the microplant’s environmental profile in relation to results of comparable technologies reported in literature. To do so, multiple technological development pathways were considered that project the current microplant’s performance into a range of future states. The impact assessment of the future PV-powered air-to-methanol plant, suggests that it is likely that methanol produced using this approach will exhibit a low (negative cradle-to-gate) climate change impact along its production chain, especially compared to conventional methanol produced via the steam reforming of natural gas. Environmental trade-offs are incurred by the additional material demand compared to conventional methanol, instilled both by the electricity generation from PV panels and the added material demand of the thousands of micro-plants that need to be produced for sufficient methanol production volume. Using polyamine sorbents for the process of capturing CO2 from the atmosphere inevitably leads to sorbent degradation which in turn can cause emissions of various substances. Using rough estimations via a worst/best case approach, it was analysed that emissions from the capture unit are relevant in three impact categories. Overall, the additional material demand and sorbent-related emissions introduce significant trade-offs in between 5-8 impact categories, depending on the followed technological scenarios. Additional technological improvement may reduce the trade-off effect, leading to a reduction of trade-off categories to a number of four. The analysis concluded that it is likely that there are benefits to using the microplant-approach to methanol production, though additional research is critical to iron out the large uncertainties that are paired with future-oriented life cycle assessment.

Green hydrogen has a pivotal place in the energy transition, addressing carbon emissions in hard-to-abate sectors. As global hydrogen demand rises, decarbonizing green production becomes vital. This study explores the influence of design choices and local weather patterns on the Carbon Footprint (CF) and Levelised Cost of Hydrogen (LCOH) for green hydrogen production. An optimisation model is developed, simulating the production chain (cradle-to-gate) and optimising it for low CF and LCOH based on location-specific wind and solar data. Three locations (Duqm, Groningen, Dakhla) and three design choices (electrolyser, PV type and wind-solar ratio) are assessed. Results indicate that local weather patterns significantly affect system performance. Dakhla boasts low production costs due to consistent solar and wind energy. Groningen has a low CF but high LCOH due to ample offshore wind but inconsistent sun. Duqm has a low LCOH but high CF due to abundant sun but inconsistent wind. Design choices, particularly the solar-wind energy ratio, strongly impact both LCOH and CF. PV technology selection also matters, with CI(G)S performing well overall. Alkaline electrolysis is preferred over PEM. The research demonstrates that design choices can substantially influence the CF, resulting in serious CF reduction at prices comparable to blue hydrogen. Future research should include storage, transportation, and off-taker aspects and expand impact categories, including social and critical raw material depletion impact categories.