Decarbonizing the building stock is critical for realizing the climate-neutral target for the Netherlands. This thesis uses multi-source data, mainly including GIS data of building footprints and... Show moreDecarbonizing the building stock is critical for realizing the climate-neutral target for the Netherlands. This thesis uses multi-source data, mainly including GIS data of building footprints and the archetypes representative of Dutch residential buildings, to develop a series of bottom-up building stock models to track future material stock and flows, energy demand, electricity generation, and GHG emissions. Results demonstrate the great potential for decarbonizing the Dutch residential building sector, while decarbonization strategies should be effectively and extensively implemented. Saving space heating energy consumption is the most direct way to reduce annual GHG emissions. Considering that most existing residential buildings will still be in use in 2050, renovating them with high energy performance standards is required. Despite the great potential of renovation, it alone is not enough to realize the climate-neutral target in the residential building stock because the upstream fossil fuel-based energy systems still emit large amounts of GHG. Replacing fossil fuels with renewable energy sources is a critical path, mainly involving onsite natural gas combustion for space heating and offsite natural gas and coal combustion for electricity and heat (in heat networks) generation. Urban mining cannot contribute to as much GHG emission reduction as energy transition strategies, though, should still be implemented as it can reduce the primary material consumption and CDW landfill. In addition to the technical aspects considered in this thesis, it is also necessary to develop feasible policies in terms of socioeconomic aspects to guarantee the effective and quick deployment of these technical strategies. Show less
Material circularity and energy efficiency are highly relevant and intertwined issues for the transition towards a carbon-neutral and circular built environment. In the Netherlands, the building... Show moreMaterial circularity and energy efficiency are highly relevant and intertwined issues for the transition towards a carbon-neutral and circular built environment. In the Netherlands, the building sector has been rendered a priority towards a circular and low-carbon society. This thesis explored potential solutions for these twin issues in light of a novel technological system. This system presents an energy–material efficiency solution for energy renovation of building stocks with prefabricated concrete elements (PCEs) with recycled CDW as feedstock. Life cycle assessment (LCA) and life cycle costing (LCC) were combined with dynamic material flow analysis (MFA) to estimate the economic and environmental implications at both a product level and a national level. Show less
In-use stocks of products can be considered as intermediaries between human needs and the physical world. During use, they fulfil important functions, but they can also be seen as a source of... Show moreIn-use stocks of products can be considered as intermediaries between human needs and the physical world. During use, they fulfil important functions, but they can also be seen as a source of materials for the future: the production of secondary materials. This idea of an urban mine is applied to copper in China in this dissertation. Taking into account that most modern technologies rely on copper, consumption of diverse copper-containing products in China is increasing rapidly. The in-use copper stocks have become a large reservoir for urban mining. It is of crucial importance to secure future supply by closing copper cycles, thereby also reducing environmental pressure. Therefore, the aim of this research is to explore how the stocks and flows related to the Chinese copper cycle can be transformed into a sustainable and circular economy. The material flow analysis and life cycle assessment approaches are used to quantify the in-use stocks, demand and waste generation for copper under the Chinese policies related to general economic development, the energy transition and ambitions with regard to circular economy, and assess associated environmental impacts as well as identify potential options to realize the dematerialization and environmental sustainability of the copper cycle in China. Show less
LCA has become an important method to study environmental impacts of human activities. Still, there are several methodological issues in LCA that can adversely affect the results reliability.... Show moreLCA has become an important method to study environmental impacts of human activities. Still, there are several methodological issues in LCA that can adversely affect the results reliability. Three of these issues relate to a) allocation, b) the representation of the time dimension and c) the interpretation of results in LCA. Uncertainties play a fundamental and underlying role for these issues. It is widely-agreed that correctly dealing with these different uncertainty sources is a vital step towards increasing the usefulness and reliability of LCA results. Practical ways to deal with uncertainty are needed. The aim of this thesis is to deepen the understanding of the uncertainty dimension of current LCA. By means of addressing different sources of uncertainty not yet addressed, with new methods, a clearer picture of the implications of different sources of uncertainty in LCA is provided. This thesis departed from broad domains of uncertainty including risk, uncertainty as conventionally described, ignorance and indeterminacies. The selected sources of uncertainty are in the domains of risk and conventional uncertainty i.e. those due to incomplete scientific knowledge and that are to some extent quantifiable. This does not mean that all can be known or quantified as ignorance and indeterminacies exist. Show less
The overall framework of the thesis is to develop an approach to compare the impacts between leaving biomass residues in fields and utilizing them for bioenergy. In this regard, residue-based... Show moreThe overall framework of the thesis is to develop an approach to compare the impacts between leaving biomass residues in fields and utilizing them for bioenergy. In this regard, residue-based bioenergy should be managed differently from product-based bioenergy. The objectives of this thesis are to identify the key issues when conducting a life cycle assessment (LCA) of residue-based bioenergy and to propose improvement in LCA procedures, specifically in the areas of life cycle inventory (LCI), life cycle impact assessment (LCIA), and methodological choices in the comparative LCA. It was discovered that the key issues associated with residue-based bioenergy relate to four primary characteristics with respect to its raw materials (biomass residues), i.e., excessive removal from plantation fields which can affect soil fertility; valuation (relative to biomass products); competing uses (bioenergy, feed, fiber, fertilizers); and treatment of biogenic carbon (assumptions of carbon neutrality vs. complete inventory). These unique features require specific LCA approaches which vary from those of conventional product-based bioenergy. These approaches include: [1] solutions to the existing dissimilar practices in the LCI of biogenic carbon; [2] an LCIA method of removing biomass residues from soil on biomass productivity; and [3] methodological choices in comparative LCA of biomass residues utilization. Show less
In the last three decades, the Life Cycle Assessment (LCA) framework has grown to establish itself as the leading tool for the assessment of the environmental impacts of product systems.LCA studies... Show moreIn the last three decades, the Life Cycle Assessment (LCA) framework has grown to establish itself as the leading tool for the assessment of the environmental impacts of product systems.LCA studies are now conducted globally both in and outside the academia and also used as a basis for policy making.Now that the science behind existing and established impact assessment models is more solid, LCA modellers may work on deepening and broadening LCA, and on tackling the issues that make the framework incomplete or uncertain.This work of thesis deals with the complete modelling of stressors that are not related to the standard extraction/emission pattern, thus that do not relate to the extraction of a certain quantity of matter or to the emission of matter to the environment.These stressors may be defined in this acceptation as matter-less.The thesis analyses the development of impact assessment models for the case of sound emissions determining noise impacts, radio-frequency electromagnetic emissions leading to electromagnetic pollution, and light emissions determining ecological light pollution.Through the study of these matter-less stressors the computational structure and other methodological topics of the LCA framework are put to the test. Show less
Environmental life cycle assessment (LCA) is a method for the quantitative assessment of the environmental impacts of products. A number of impact categories are related to toxic effects of... Show moreEnvironmental life cycle assessment (LCA) is a method for the quantitative assessment of the environmental impacts of products. A number of impact categories are related to toxic effects of chemicals. Multimedia models for substance fate, supplemented with models for human exposure, have been developed in the context of human and environmental risk assessment (HERA). Different authors have adapted such models for use in LCA, largely on a continental level. It has sometimes been suggested to merge LCA toxicity assessment and HERA into one common tool. Here, it is demonstrated that LCA and HERA cannot be merged, due to a fundamental difference concerning their respective goals. Subsequently, adaptations to existing multimedia models are proposed to make it possible to extend multimedia models with a module for metals. The core of the thesis is formed by the GLOBOX model: a global, regionally differentiated fate, intake and effect model for LCA toxicity assessment. For emissions of any organic chemical or metal to any compartment in any country or at any sea, this model calculates region-specific characterisation factors. Finally, an updated set of LCA normalisation factors is provided, with which the relative contributions of a product to the different impact categories can be evaluated. Show less
To understand the contribution of biomass refining to sustainable development, the technical, environmental and economic aspects are summarized in this thesis. This work begins from life cycle... Show moreTo understand the contribution of biomass refining to sustainable development, the technical, environmental and economic aspects are summarized in this thesis. This work begins from life cycle assessment (LCA) of bioethanol from lignocellulosic feedstocks such as corn stover, sugarcane and bagasse, and switchgrass. The findings from these studies present a clear example of problem shifting – solving the problems of oil depletion and ozone layer depletion at the expenses of increasing agricultural related emissions. Then this work continues with energy analyses of bioethanol from lignocellulosic feedstocks in comparison with selected literature studies. The results indicate that a single-product (ethanol) system can be optimized only to a certain extent due to the fixed process options and relatively low price of ethanol. Therefore, the last part of this thesis focuses on design and system analysis of a lignocellulosic feedstock biorefinery producing fuel, chemicals and power in one plant, and analyzes the environmental and economic potential of such a refinery. The outcomes demonstrate that multi-product biorefining is indeed more feasible and profitable than single-output productions such as ethanol plant. Social aspects are beyond the scope of this study. Show less
