Carbon dioxide is released by natural and anthropogenic processes, such as the production and combustion of fossil fuels. Production of biogas also generates carbon dioxide, but of biogenic origin. The global, yearly emissions of greenhouse gases are regularly increasing, although agreements such as the Paris Agreement is signed by parties globally. Sweden has the goal to reach net-zero emissions by 2045, and thereafter to only obtain negative emission levels. To reach these goals the biogenic version of Carbon Capture and Storage (CCS) called Bioenergy with Carbon Capture and Storage (BECCS) is considered to be an essential strategy. Using carbon dioxide, through Carbon Capture and Utilization (CCU), in for example products, can complement BECCS since the strategy can increase the value of carbon dioxide. These strategies make it possible to reduce the climate impact of biogas production.  This master thesis aimed to chart different techniques in CCS and CCU to examine how they can be used to utilize or store carbon dioxide from biogas plants. What technical demands different solutions create was explored. The different techniques were assessed through a multi criteria analysis by a technological, environmental, marketable and economical standpoint to investigate which ones were the most suitable for a specific, studied case – Tekniska verken’s biogas plant. One suitable technique within CCU was analyzed through a screening of actors in the region. An environmental assessment of one technique in CCS and one in CCU were compared with the reference case Business as usual, to explore how a simulated biogas plant’s climate impact can change through the implementation of CCS and CCU.  The charting of literature gave findings of 42 different techniques, which were sifted down to 7; algae farming for wastewater treatment, BECCS in saltwater aquifers, carbon dioxide curing of concrete, bulk solutions, production of methanol, production of methane through Power To Gas and crop yield boosting in greenhouses. The multi criteria analysis pointed out carbon dioxide curing of concrete and BECCS in saltwater aquifers as suitable solutions for the studied case. The implementation of these techniques requires a liquefaction plant, infrastructure for transportation as well as business partners.  A life cycle assessment of the studied cases climate impact was given through modelling and simulation of a model plant of the studied case, with the functional unit 1 Nm3 biomethane. The reference case Business as usual had a climate impact of 0,38 kg CO2 eq, which corresponds to approximately one eighth of the climate impact of fossil fuels such as gasoline or diesel. By storing the carbon dioxide through BECCS in saltwater aquifers the climate impact decreased to - 0,42 kg CO2 eq. By utilizing the carbon dioxide through curing of concrete the biomethane’s climate impact decreased to -0,72 kg CO2 eq. The results thereby evince that Swedish biogas producers can improve their climate performance through CCS and CCU. / Koldioxid släpps ut av såväl naturliga som antropogena processer, exempelvis vid produktion och förbränning av fossila bränslen. Även vid biogasproduktion uppkommer koldioxid, men av biogent ursprung. Årliga globala utsläpp av växthusgaser ökar regelbundet, trots överenskommelser som Parisavtalet som syftar till att begränsa klimatförändringarna. Sverige ska nå nettonollutsläpp senast 2045 och därefter ha negativa utsläppsnivåer. För att uppnå detta mål anses en biogen version av Carbon Capture and Storage (CCS), det vill säga avskiljning och lagring av koldioxid, kallad Bioenergy with Carbon Capture and Storage (BECCS) vara en essentiell strategi. Tillvaratagande av koldioxid, genom Carbon Capture and Utilization (CCU), kan ge ett bra komplement till BECCS eftersom det nyttiggör koldioxid i produkter och kan öka värdet av koldioxid. Tekniker inom CCS och CCU möjliggör minskad klimatpåverkan inom biogasproduktion.  Detta examensarbete syftade till att kartlägga olika alternativ inom teknikerna CCS och CCU för att undersöka hur dessa kan användas för att nyttiggöra eller lagra koldioxid från biogasanläggningar, samt att undersöka vilka tekniska krav som ges av lösningarna. Utifrån en multikriterieanalys bedömdes vilka lösningar som var tekniskt, miljömässigt, marknadsmässigt och ekonomiskt motiverade för tillvaratagande av koldioxid. Bedömningen genomfördes genom att studera specifikt fall som var Tekniska verken i Linköpings biogasanläggning. Den lösning som valdes ut som lämplig inom CCU analyserades ur ett marknadsmässigt perspektiv genom en översiktlig kartläggning av aktörer i regionen. Därefter studerades klimatpåverkan från en förenklad modell av Tekniska verkens biogasanläggning för att undersöka hur denna förändras vid implementering av en lämplig lösning inom CCS respektive CCU.  Genom en screening av lösningsförslag identifierades 42 lösningsförslag inom CCS och CCU som sållades ner till sju stycken; algodling vid vattenrening, BECCS i saltvattenakviferer, betong härdad av koldioxid, bulklösning, metanoltillverkning, tillverkning av metan genom Power To Gas samt växthusodling. Multikriterieanalysen visade att koldioxidhärdad betong inom CCU och BECCS i saltvattenakviferer inom CCS var lämpliga lösningar för det studerade fallet. För implementering av förslagen krävdes bland annat en förvätskningsanläggning, infrastruktur för transport och samarbetspartners.  De studerade scenariernas klimatmässiga livscykel erhölls genom modellering och simulering av en modellanläggning av det studerade fallets biogasanläggning i programvaran SimaPro med användning av den funktionella enheten 1 Nm3 fordonsgas. Resultatet visade att fordonsgasen i referensfallet har en klimatpåverkan på 0,38 kg koldioxidekvivalenter. Fordonsgasens klimatpåverkan var cirka en åttondel av fossila bränslen såsom bensin och diesels klimatpåverkan. Vid lagring av koldioxid genom BECCS i saltvattenakviferer förändrades klimatpåverkan till - 0,42 kg koldioxidekvivalenter. När koldioxid användes till härdning av betong förändrades fordonsgasens klimatpåverkan till -0,72 kg koldioxidekvivalenter. Detta innebär att svenska producenter av biogas kan förbättra sin klimatpåverkan genom såväl lösningar inom CCS som CCU.

I denna avhandling studeras en ny teknik för att hantera växthuseffekten. Den nya tekniken heter koldioxidavskiljning och lagring (CCS) och granskades av FN:s klimatpanel 2005 och tillskrevs då möjligheterna att stå för 15-55% av alla CO2-reducering fram till 2100 och detta till en 30% lägre kostnad än vad som annars vore möjligt. EU är en framträdande pådrivare av CCS och för fram att växthuseffekten inte kan hanteras utan att CCS implementeras skyndsamt. CCS beskrivs i dessa sammanhang som en hållbar teknik. CCS är emellertid förbunden med långtidslagring, en betydande teknisk komplexitet och tillämpas främst på kolkraftverk. Storskaliga satsningar på CCS kan medföra att kolanvändningen ökar. Syftet med avhandlingen är att analysera de vetenskapliga och politiska ansträngningarna att visa att CCS är en eftersträvansvärd teknik för att hantera växthuseffekten. Utifrån perspektivet ekologisk modernisering och genom granskning av studier av vetenskapliga rapporter, artiklar i massmedia, politiska dokument och intervjuer genomförs studien. Scenerier och prognoser har en central funktion för att kunna påvisa att CCS är en eftersträvansvärd teknik. I flera av dessa scenarier framställs en närmast linjär teknikutveckling och flera betydelsefulla problem och hinder bortses från. CCS framstår som en teknik med stor teknisk och ekonomisk potential och i massmedia beskrivs CCS ofta som oumbärlig. En mer nyanserad bild framträder vid intervjuer med CCS-experter då fler osäkerheter och hinder lyfts fram. Förståelsen för varför denna teknik för stöd av många starka aktörer blir även tydligare. Den dominerande beskrivningen av CCS egenskaper och inverkan på energisystemen ligger i linje med det som är utmärkande för den ekologiska modernisering och således även för det dominerande sättet att bedriva energi- och klimatpolitik idag. / In this dissertation an emerging technology to manage climate change is studied. The technology is carbon dioxide capture and storage (CCS) and was reviewed by the IPCC in 2005. IPCC claims that CCS could contribute 15–55% to the cumulative mitigation effort worldwide until 2100 and reduce the costs of stabilizing CO2 concentrations by 30%. The EU promotes CCS and believes that climate change cannot be managed unless CCS is promptly implemented. In this context CCS is labelled as a sustainable technology. However CCS deals with long-term waste disposal, a significant technological complexity and is meant to be installed mainly in coal-fired power plants. Large scale implementation of CCS might lead to a rise in coal usage and concerns are raised this will impede the development of renewable energy. The aim of this dissertation is to analyze the scientific and political efforts to show that CCS is a rational and viable solution to the climate change problems. The study is conducted from the perspective of ecological modernization and is undertaken through a review of scientific reports, mass media articles, political documents and interviews. Scenarios and prognoses have a central position in making a future of large-scale CCS implementation plausible: through the scenarios, a linear development trend is visualized in which technological and scientific problems are assumed to be solved as CCS is implemented. CCS is described as a technology with substantial potential and is in the mass media often pictured as indispensable. A more nuanced picture appears when analyzing interviews with CCS-experts. The understanding of why this technology is supported by several influential actors is deepened. The dominating description of CCS and impact on the energy systems is compatible to the characteristics of ecological modernization and thus also to the predominating way of practising energy and climate politics today.

Hydrogen (H2) represents an energy carrier endowed with the potential to contribute to the design of a robust and reliable global energy system by complementing electricity as well as liquid fuels use in an environmentally responsible manner provided that the pertinent H2 production technologies (conventional and new ones) can reach techno-economically attractive performance levels in the presence of irreducible (macroeconomic, fuel market, regulatory) uncertainty. Indeed, the role of H2 in the global energy economy is widely recognized as significant in light also of fast-growing demand in the petrochemical and chemical processing sector as well as future regulatory action on greenhouse gas emissions. Pd and Pd/Alloy-based catalytic membrane reactor (CMR) modules potentially integrated into H2 production (HP-CMR) process systems offer a promising technical pathway towards H2 production with enhanced environmental performance in a carbon-constrained world. However, the lack of accumulated operating experience for HP-CMR plants on the commercial scale poses significant challenges. Therefore, any preliminary attempt to assess their economic viability is certainly justified. A comprehensive techno-economic performance assessment framework has been developed for HP-CMRs with CO2 capture capabilities. A functional Net Present Value (NPV) model has been developed first to evaluate the economic viability of HP-CMRs. The plant/project value of HP-CMR is compared to other competing technology options such as traditional coal-gasification and methane steam reforming-based hydrogen production plants with and without CO2 capture. Sources of irreducible uncertainty (market and regulatory) as well as technology risks are explicitly recognized and the effect of these uncertainty drivers on the plant’s/project’s value is taken into account using Monte-Carlo techniques. Therefore, more realistic distribution profiles of the plant’s economic performance outcomes are generated rather than single-point value estimates. It is shown that future regulatory action on CO2 emissions could induce appealing NPV-distribution profiles for HP-CMRs in the presence of uncertainty and technology risks. Finally, the valuation assessment is complemented with a sensitivity analysis for different representative values of the discount rate that span a reasonable range associated with business and financing risks. It apparently indicates that creatively structured financing mechanisms leading to a reduction of the cost of capital/discount rate could induce more appealing economic performance outcomes and valuation profiles. Furthermore, the proposed research work aims at the development of a methodological framework to assess the economic value of flexible alternatives in the design and operation of HP-CMR plants with carbon capture capabilities under the aforementioned sources of uncertainty. The main objective is to demonstrate the potential value enhancement associated with the long-term economic performance of flexible HP-CMR project investments by managing the uncertainty associated with future environmental regulations. Within the proposed context, promising design flexibility concepts for HP-CMR plants are introduced and operational as well as constructional flexibility options are identified and assessed. In particular, operational flexibility will be realized through periodic and temporary shutdowns of the carbon capture unit in response to regulatory uncertainties. Constructional flexibility will be realized by considering the installation of a carbon capture unit at three strategic periods: 1) installation in the initial design phase, 2) retrofitting at a later stage and 3) retrofitting with preinvestment. Monte Carlo simulations and financial analysis will be conducted in order to demonstrate that, in the presence of irreducible uncertainty, design flexibility options could lead to economic performance enhancement of HP-CMR plants by actively responding to the above sources of uncertainty as they get resolved over the plant’s lifetime.

L'atténuation du changement climatique est l'un des défis majeurs de notre époque. Les émissions anthropiques de gaz à effet de serre ont augmenté de façon continue depuis la révolution industrielle, provoquant le réchauffement climatique. Un ensemble de technologies très diverses doivent être mises en œuvre pour respecter les accords internationaux relatifs aux émissions de gaz à effet de serre. Certaines d'entre elles ont recours au sous-sol pour le stockage de diverses substances. Cette thèse traite plus particulièrement de la dynamique du stockage souterrain du dioxyde de carbone (CO2) et de l'hydrogène (H2). Des modèles numériques de transport réactif et multiphasiques ont été élaborés pour mieux comprendre la migration et les interactions des fluides dans des milieux poreux de stockage souterrain. Ils fournissent des recommandations pour améliorer l'efficacité, la surveillance et la sécurité du stockage. Trois modèles sont présentés dans ce document, dont deux dans le domaine du captage et du stockage du CO2 (CCS pour Carbon Capture and Storage), et le troisième s'appliquant au stockage souterrain de l'hydrogène (UHS pour Underground Hydrogen Storage). Chacun d'entre eux traite plus spécifiquement un aspect de la recherche : Modèle multiphasique appliqué au CCS L'efficacité et la sécurité à long terme du stockage du CO2 dépend de la migration et du piégeage du panache de CO2 flottant. Les grandes différences d'échelles temporelles et spatiales concernées posent de gros problèmes pour évaluer les mécanismes de piégeage et leurs interactions. Dans cet article, un modèle numérique dynamique diphasique a été appliqué à une structure aquifère synclinale-anticlinale. Ce modèle est capable de rendre compte des effets de capillarité, de dissolution et de mélange convectif sur la migration du panache. Dans les aquifères anticlinaux, la pente de l'aquifère et la distance de l'injection à la crête de l'anticlinal déterminent la migration du courant gravitaire et, donc, les mécanismes de piégeage affectant le CO2. La structure anticlinale arrête le courant gravitaire et facilite l'accumulation du CO2 en phase libre, en dessous de la crête de l'anticlinal, ce qui stimule la mise en place d'une convection et accélère donc la dissolution du CO2. Les variations de vitesse du courant gravitaire en raison de la pente de l'anticlinal peuvent provoquer la division du panache et une durée différente de résorption du panache en phase libre, qui dépend de l'endroit de l'injection. / Climate change mitigation is one of the major challenges of our time. The anthropogenic greenhouse gases emissions have continuously increased since industrial revolution leading to global warming. A broad portfolio of mitigation technologies has to be implemented to fulfill international greenhouse gas emissions agreements. Some of them comprises the use of the underground as a storage of various substances. In particular, this thesis addresses the dynamics of carbon dioxide (CO2) and hydrogen (H2) underground storage. Numerical models are a very useful tool to estimate the processes taking place at the subsurface. During this thesis, a solute transport in porous media module and various multiphase flow formulations have been implemented in COMSOL Multiphysics (Comsol, 2016). These numerical tools help to progress in the understanding of the migration and interaction of fluids in porous underground storages. Three models that provide recommendations to improve the efficiency, monitoring and safety of the storages are presented in this manuscript: two in the context of carbon capture and storage (CCS) and one applied to underground hydrogen storage (UHS). Each model focus on a specific research question: Multiphase model on CCS. The efficiency and long-term safety of underground CO2 storage depend on the migration and trapping of the buoyant CO2 plume. The wide range of temporal and spatial scales involved poses challenges in the assessment of the trapping mechanisms and the interaction between them. In this chapter a two-phase dynamic numerical model able to capture the effects of capillarity, dissolution and convective mixing on the plume migration is applied to a syncline-anticline aquifer structure. In anticline aquifers, the slope of the aquifer and the distance of injection to anticline crest determine the gravity current migration and, thus, the trapping mechanisms affecting the CO2. The anticline structure halts the gravity current and promotes free-phase CO2 accumulation beneath the anticline crest, stimulating the onset of convection and, thus, accelerating CO2 dissolution. Variations on the gravity current velocity due to the anticline slope can lead to plume splitting and different free-phase plume depletion time is observed depending on the injection location. Injection at short distances from the anticline crest minimizes the plume extent but retards CO2 immobilization. On the contrary, injection at large distances from anticline crest leads to large plume footprints and the splitting of the free-phase plume. The larger extension yields higher leakage risk than injection close to aquifer tip; however, capillary trapping is greatly enhanced, leading to faster free-phase CO2 immobilization. Reactive transport model on convective mixing in CCS. Dissolution of carbon-dioxide into formation fluids during carbon capture and storage (CCS) can generate an instability with a denser CO2-rich fluid located above the less dense native aquifer fluid. This instability promotes convective mixing, enhancing CO2 dissolution and favouring the storage safety.

Dans un contexte de croissance effrénée de la demande mondiale d'énergie et de pression environnementale pour lutter contre le réchauffement climatique, cette thèse étudie une des technologies envisagées pour réduire les émissions de dioxyde de carbone (CO2) : la capture et le stockage géologique du carbone (CSC). Nous étudions principalement l’application de cette technologie à la production des bioénergies (BCSC) car ce procédé permet d’épurer l’atmosphère tout en fournissant un substitut énergétique non polluant aux énergies fossiles. La première partie de ce travail analyse le potentiel économique et environnemental de la technologie de BCSC. Tout d'abord, une évaluation économique et environnementale de la BCSC dans le secteur de la production de bioéthanol en France est conduite.Ensuite, grâce à un modèle bottom-up d’optimisation TIAM-FR, nous étudions le potentiel global et régional de cette technologie dans le secteur de l'électricité. Enfin, les incitations économiques à mettre en place pour assurer son développement sont mises en évidences. Dans la deuxième partie, un modèle d'équilibre général calculable est utilisé pour évaluer les politiques environnementales. Nous construisons le modèle théorique en introduisant les technologies de CSC et de BCSC ainsi qu’une large variété d’instruments économiques. Le modèle est ensuite calibré pour comparer l’efficacité économique des instruments de politique environnementale à un niveau mondial et à un niveau français. / In a context of unbridled growth of global energy demand and environmental pressure in the fight againstglobal warming, this thesis studies one of the proposed technologies to reduce carbon dioxide (CO2)emissions: carbon capture and geological storage (CCS). We therefore consider the application of thistechnology to the production of bioenergies (BCCS) because this technology allows purifying theatmosphere while providing a clean energy alternative to fossil fuels. The first part of this work analyzesthe economic and environmental potential of BCCS. First, an economic and environmental assessment ofBCCS in the bioethanol production in France is conducted. Then, using the bottom-up optimization modelTIAM-FR, we study the global and regional potential of this technology in the electricity sector. Finally,the economic incentives that need to be provided to ensure BCCS deployment are highlighted. In thesecond part, a general equilibrium model is used to evaluate environmental policies. We construct thetheoretical model by introducing the CCS and BCCS as well as a wide range of economic instruments.The model is then calibrated to compare the effectiveness of environmental policy instruments at a globallevel and at a French level.

Au cœur de cette thèse réside l'application des méthodes d'optimisation et d'études empiriques pour traiter des questions de développement durable dans le secteur de l'électricité du Vietnam pour les 30 prochaines années. On examine les moyens des options énergétiques durables pour le secteur de l'électricité. La thèse s'organise en deux parties. (i) Dans la première partie, nous développons le modèle " bottom-up " de planification intégrée des ressources (IRP) pour fournir une évaluation plus exhaustive de l'état actuel et des perspectives d'avenir pour le secteur de l'électricité du Vietnam dans les trois prochaines décennies. Puis, en utilisant une analyse comparative et une analyse de la vulnérabilité qui est basée sur la simulation IRP, nous analysons les vulnérabilités auxquelles le développement du secteur devra faire face, en termes de dimensions économiques et socio-environnementales. Nous avons en outre développé le modèle IRP, représentant les coûts marginaux de réduction des émissions de carbone de manière réaliste en tenant compte des valeurs non nulles de carbone et de limitation des émissions de carbone, afin de simuler des options d'approvisionnement énergétique soutenables pour le secteur de l'énergie. (ii) Dans la deuxième partie, nous étudions les principaux obstacles contre une adoption plus large des énergies soutenables à l'aide d'enquêtes formelles parmi les experts nationaux. Ensuite, nous utilisons une approche d'analyse empirique pour examiner les différents outils politiques appropriés, y compris des instruments d'incitation / régimes et la réforme du secteur pour une telle durabilité du secteur de l'énergie. Pour la fin, nous analysons l'accès aux sources de financement possibles pour le développement durable dans le secteur de l'électricité du Vietnam.

Today’s carbon constrained world with its increasing demand for cheap energy and a fossil fuel intensive fleet of power producers is making carbon capture and storage (CCS) desirable. Several CCS technologies are under investigation by various research and development groups globally. One of the more promising technologies is oxy-fuel combustion, since it produces a CO2 rich flue gas which requires minor processing to meet storage condition requirements. In this study the economics of an advanced super critical oxy-coal power plant burning lignite, simulated in-house was assessed. A robust and user-friendly financial tool box has been developed with commonly acceptable default parameter settings. Capital, operation and maintenance costs were estimated along with corresponding levelized cost of electricity and CO2 avoidance costs calculated using the detailed financial model developed. A levelized cost of electricity of 131 $/MWhrnet along with a levelized CO2 avoidance cost of 64 $/tonne was estimated for an ASC oxy-coal power plant with CO2 capture. Also a levelized cost of electricity of 83 $/MWhrnet was estimated for an ASC air-fired coal power plant without CO2 capture capabilities as the base plant. The price of electricity was observed to increase from 83 $/MWhrnet to 131 $/MWhrnet translating into a 57% increase. The sensitivity of the overall economics of the process was assessed to several parameters. The overall economics was found sensitive to the choice chemical engineering plant cost index (CEPCI), capacity factor, size of power plant, debt ratio, fuel price, interest rate, and construction duration.

The primary objective was to predict the relative storage capacity of carbonate rocks relevant for carbon dioxide sequestration. To achieve this, a detailed pore scale characterization of model carbonate rocks, Indiana Limestone and Pink Dolomite, was conducted utilizing micro-computed tomography (microCT) data using pore network modeling and invasion percolation simulations. For the first time in literature, Pink Dolomite’s pore space characteristics were analyzed. A secondary objective was to compare thresholding techniques as applied to carbonates which exhibit dual porosity (porosity at multiple length scales). The analysis showed the sensitivity of existing methods to the thresholding technique, imaging method and material. Overall, the contributions of this work provide an assessment of two carbonates relevant for carbon capture and storage at the pore scale; and a preliminary assessment into thresholding dual porosity carbonates.

The primary objective was to predict the relative storage capacity of carbonate rocks relevant for carbon dioxide sequestration. To achieve this, a detailed pore scale characterization of model carbonate rocks, Indiana Limestone and Pink Dolomite, was conducted utilizing micro-computed tomography (microCT) data using pore network modeling and invasion percolation simulations. For the first time in literature, Pink Dolomite’s pore space characteristics were analyzed. A secondary objective was to compare thresholding techniques as applied to carbonates which exhibit dual porosity (porosity at multiple length scales). The analysis showed the sensitivity of existing methods to the thresholding technique, imaging method and material. Overall, the contributions of this work provide an assessment of two carbonates relevant for carbon capture and storage at the pore scale; and a preliminary assessment into thresholding dual porosity carbonates.

Today???s carbon constrained world with its increasing demand for cheap energy and a fossil fuel intensive fleet of power producers is making carbon capture and storage (CCS) desirable. Several CCS technologies are under investigation by various research and development groups globally. One of the more promising technologies is oxy-fuel combustion, since it produces a CO2 rich flue gas which requires minor processing to meet storage condition requirements. In this study the economics of an advanced super critical oxy-coal power plant burning lignite, simulated in-house was assessed. A robust and user-friendly financial tool box has been developed with commonly acceptable default parameter settings. Capital, operation and maintenance costs were estimated along with corresponding levelized cost of electricity and CO2 avoidance costs calculated using the detailed financial model developed. A levelized cost of electricity of 131 $/MWhrnet along with a levelized CO2 avoidance cost of 64 $/tonne was estimated for an ASC oxy-coal power plant with CO2 capture. Also a levelized cost of electricity of 83 $/MWhrnet was estimated for an ASC air-fired coal power plant without CO2 capture capabilities as the base plant. The price of electricity was observed to increase from 83 $/MWhrnet to 131 $/MWhrnet translating into a 57% increase. The sensitivity of the overall economics of the process was assessed to several parameters. The overall economics was found sensitive to the choice chemical engineering plant cost index (CEPCI), capacity factor, size of power plant, debt ratio, fuel price, interest rate, and construction duration.