Abstract Energy production in combustion power plants is a significant source of anthropogenic carbon dioxide emissions. The targets of international climate agreements call for utilizing all available technologies to achieve rapid and cost-effective emission reductions. Carbon capture and storage is one of the possible technical solutions applied in combustion power plants. Circulating fluidized bed boilers have gained increasing popularity due to advantages in availability, emission control, fuel flexibility and option for using challenging fuels, and the possibility of using high-efficiency steam cycles. In the novel process of oxy-combustion, combustion air is replaced by a mixture of oxygen and recycled flue gas to facilitate the capture of carbon dioxide from the flue gas flow. Additional degrees of freedom become available for combustion control as the gas flow and composition can be controlled separately for fluidization and combustion purposes. In the research for this thesis, self-optimizing control was applied for the control structure design of a circulating fluidized bed boiler. Self-optimizing control offers a systematic tool for the early phases of control design, in which decisions have traditionally been made based on intuition, heuristics and previous experience. The self-optimizing control approach searches for controlled variables without a need for constant setpoint optimization when the process is affected by disturbances and implementation errors. Results presented in the thesis show that self-optimizing control can be applied in the control structure design of circulating fluidized bed combustion. A range of control structure alternatives were evaluated using steady-state approximations of a validated process model. For the novel oxy-combustion process, promising control structures were identified and could be dynamically demonstrated. / Tiivistelmä Energiantuotanto polttovoimalaitoksissa on merkittävä hiilidioksidipäästöjen lähde. Kansainväliset ilmastotavoitteet edellyttävät kaikkien käytettävissä olevien teknologioiden hyödyntämistä päästövähennysten aikaansaamiseksi nopeasti ja kustannustehokkaasti. Hiilidioksidin talteenotto on yksi mahdollisista teknisistä ratkaisuista polttovoimalaitoksissa. Kiertoleijukattilat ovat saavuttaneet kasvavaa suosiota etuinaan hyvä käytettävyys, tehokas päästöjen hallinta, soveltuvuus erilaisten haastavienkin polttoaineiden hyödyntämiseen ja mahdollisuus tehokkaiden höyrykiertojen käyttöön. Uudessa happipolttoprosessissa palamisilma korvataan hapen ja kierrätetyn savukaasun seoksella, mikä mahdollistaa hiilidioksidin talteenoton savukaasuista. Kiertoleijupolton säädön kannalta vapausasteet lisääntyvät, sillä leijutukseen ja polttamiseen käytettävän kaasun määrää ja koostumusta voidaan säätää erikseen. Väitöstutkimuksessa käytettiin itseoptimoivaa säätöä kiertoleijukattilan säätörakenteiden suunnitteluun. Itseoptimoiva säätö tarjoaa systemaattisen menetelmän säätösuunnittelun alkuvaiheeseen, jossa päätöksenteko on perinteisesti tehty esimerkiksi intuition, heuristiikan ja aiempien ratkaisujen perusteella. Menetelmän tavoitteena on löytää säädettävät muuttujat, joiden asetusarvot eivät vaadi jatkuvaa optimointia, vaikka prosessiin vaikuttavat erilaiset häiriöt ja mittausvirheet. Väitöstutkimuksen tulokset osoittavat, että itseoptimoiva säätö soveltuu kiertoleijupolton säätörakenteiden suunnitteluun. Erilaisten säätörakenteiden toimivuutta arvioitiin käyttäen validoidun prosessimallin tasapainotilan approksimaatioita. Uudelle happipolttoprosessille löydettiin lupaavia säätörakenteita, joiden toimintaa voitiin demonstroida myös dynaamisesti.

Submitted by Morgana Andrade (morgana.andrade@ufes.br) on 2016-04-08T19:15:45Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) tese_9214_Pedro Junior Zucatelli - verso final.pdf: 4865384 bytes, checksum: 570b50189e5399bc757b7e56ec6fff81 (MD5) / Approved for entry into archive by Patricia Barros (patricia.barros@ufes.br) on 2016-05-13T13:42:31Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) tese_9214_Pedro Junior Zucatelli - verso final.pdf: 4865384 bytes, checksum: 570b50189e5399bc757b7e56ec6fff81 (MD5) / Made available in DSpace on 2016-05-13T13:42:31Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) tese_9214_Pedro Junior Zucatelli - verso final.pdf: 4865384 bytes, checksum: 570b50189e5399bc757b7e56ec6fff81 (MD5) / Conforme reconhecido pelo Protocolo de Kyoto, planejar um futuro energético ecologicamente correto é o grande desafio do Século XXI. Os padrões atuais de recursos energéticos e de uso de energia se mostram prejudiciais para o bem-estar da humanidade ao longo prazo. A integridade dos sistemas naturais essenciais já está em risco devido às mudanças climáticas causadas pelas intensas emissões dos Gases de Efeito Estufa na atmosfera. Neste contexto, o Sequestro Geológico de Carbono (ou Carbon Capture and Storage – CCS) é uma atividade promissora que visa contribuir para a redução da emissão dos gases causadores do efeito estufa e a mitigação das alterações climáticas, por meio da captura, transporte e armazenamento de CO2 em formações geológicas adequadas (aquíferos salinos, reservatórios de hidrocarbonetos e reservatórios de carvão). Portanto, inserida neste cenário, esta Dissertação teve como objetivo analisar o potencial técnico do sequestro geológico de CO2 na Bacia do Espírito Santo onshore e offshore abordando os ambientes geológicos propícios para a aplicação de projetos de CCS, as fases que compõem estes projetos, seus investimentos e custos operacionais. Além disso, foi realizada a modelagem matemática da potencialidade de armazenamento assim como a estimativa de rentabilidade financeira com a execução do projeto de armazenamento por meio da venda do óleo extra produzido pela técnica de recuperação avançada de petróleo e pela comercialização dos Créditos de Carbono. Para isso, este projeto teve como estratégia metodológica: a xviii pesquisa exploratória e a revisão da literatura relacionada com o tema, a coleta de dados secundários, via análise de documentos, e a coleta de dados primários, via entrevistas com experts e participações em congressos nacionais e internacionais voltados para o tema. Sendo assim, conclui-se que os projetos de CCS são possíveis de implantação no estado do Espírito Santo, isto porque além da estrutura geológica dos reservatórios de petróleo e gás da bacia capixaba contribuir para bons resultados (pois, na maioria dos casos, são reservatórios areníticos com presença de rocha selante), o potencial dos aquíferos salinos capixabas e o potencial dos campos de hidrocarbonetos estudados nesta dissertação (Campo de Golfinho, Inhambú, Fazenda Alegre, Cação, Canapu, Cangoá, Peroá e Camarupim) merecem destaque nacional; entretanto, a falta de maturidade dos setores privado e público, com relação ao gerenciamento dos projetos desta natureza e ao seu uso em larga escala, impede o avanço de tais tecnologias no estado do Espírito Santo e, por consequência, no Brasil. / According to the Kyoto Protocol, planning an ecologically sustainable future is the greatest challenge of the 21st Century. Current patterns of energy resources and energy use are shown detrimental to the welfare of mankind in the long run. The integrity of essential natural systems is already at risk because of the climate change caused by the intense emission of greenhouse gases into the atmosphere. In this context, the Carbon Capture and Storage (CCS) technology is a promising activity that aims to reduce the emission of gases responsible by the greenhouse effect and climate change mitigation through CO2 capture, transport and storage in suitable geological formations (saline aquifers, coal reservoirs, oil and gas reservoirs). Therefore, inserted in this context, this dissertation has how objective analysis of the technical potential for carbon capture and geological sequestration of Espírito Santo onshore and offshore basin addressing amenable geologic environments to the application of CCS projects, phases that make up these projects, their investments and operational costs and the development of mathematical modeling for the calculations regarding the storage capability and calculation of estimated financial profitability along with its execution through the sale of extra oil produced by the advanced recovery technique of oil and the sale of carbon credits. For that, this project had how methodological strategy: the exploratory research and review of the literature on the subject, the collection of secondary data, via document analysis, and xx collecting primary data via interviews with experts and participation in national and international congress geared for the theme. Therefore, it is concluded that CCS projects are possible deployment in the state of Espírito Santo, this is because in addition to the geological structure of oil and gas reservoirs in the Espírito Santo basin contribute to good results (as, in most cases, are sandstone reservoirs with presence of seal rock), the potential of saline aquifers and the potential of hydrocarbon fields studied in this dissertation (Golfinho, Inhambú, Fazenda Alegre, Cação, Canapu, Cangoá, Peroá and Camarupim) deserve national recognition; however, the lack of maturity of the private and public sectors, with respect to the management of projects of this nature and their widespread use, prevents the advancement of such technologies in the state of Espírito Santo and therefore in Brazil.

Given the growing worldwide interest in fossil fuels on one hand and mitigation of climate change on the other hand, it is necessary to research into new technologies as Carbon Capture and Storage. This technology became a matter of interest as an option to diminish greenhouse gas emissions of power plants. It is essential to find out about the costs of Carbon Capture and Storage and expected future costs of power plants with CCS. Impact of this techology is not only in the sphere of capital and operational costs, but it also influences power plant efficiency and fuel consumption in negative way. Analysis of reductions in the costs of this technology as a result of learning-by-doing is observed on Experience Curves. This study observes influence of CCS on costs of mainly PC, IGCC and NGCC type of power plant. CCS technology has positive impact not only on environment, but it is possible to assess Enhanced Oil, Methane or Gas Recovery, which can partly offset costs of this technology.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21129号 / 工博第4493号 / 新制||工||1698(附属図書館) / 京都大学大学院工学研究科化学工学専攻 / (主査)教授 宮原 稔, 教授 山本 量一, 教授 佐野 紀彰 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Utsläpp av CO2 till atmosfären bidrar till ökningen av globala temperaturer. Industrisektorn står för 20 % av utsläppen och utav dessa kommer 6 % från pappers- och massaindustrin. För att lyckas minska den globala temperaturhöjningen till under 1,5 °C hjälper det inte bara att minska utsläppen. Även negativa utsläpp måste genereras. Syftet med denna studie är att undersöka implementeringen av CLG för att separera CO2 på ett energieffektivt sätt och samtidigt generera H2 och elektricitet. Processanalyser genomfördes för att undersöka möjligheten att implementera CLG-processen till ett typiskt massabruk. Processmodeller togs fram for att undersöka CLG, värmeåtervinning samt elektricitetsgenerering. Processmodellerna utvecklades med hjälp av Aspen Plus och Aspen HYSYS. De framtagna modellerna analyserades sedan med avseende på olika designparametrar inom CLG-processen. På ett typiskt massabruk som producerar 800 000 adt varje år kan 375 kg CO2/adt separeras och då uppnå negativa utsläpp, genom att byta ut multi-fuel forsrännaren med en CLG process. Den framtagna processmodellen skulle också kunna generera 360-504 kWh/adt av H2 beroende på de designparametrar som används för CLG-processen. Enligt modellen kan värme som återvinns från processen användas för att fånga upp ytterligare 13 % av CO2 från andra delar av bruket. Processanalys för olika designparametrar inom CLG systemet så som temperatur, luftflöde och flödet av syrgasbärare har presenterats. Nyckeltalen som undersöktes var den mängd CO2 som kunde fångas upp, mängd H2 genererad samt överskottet av elektricitet som produceras när multi-fuel förbränningen byts ut mot en CLG-process på ett typiskt massa bruk. / Emissions of CO2 to the atmosphere are contributing to the global temperature rise. The industrial sector contributed to 20 % of the emissions and out of that, 6 % are generated from the pulp and paper industry. To limit the temperature increase below 1,5 °C, the emissions not only need to be reduced but also negative emissions should be generated from different sectors. The purpose of this study is to realize the implementation of Chemical Looping Gasification (CLG) to separate CO2 (for permanent storage) in an energy-efficient way while co-generating H2 as well as electricity. Process analysis was carried out to investigate the possibility of substituting the multifuel boiler in a typical pulp mill with a CLG process. Process models for the CLG, heat recovery and electricity generation process were developed using AspenPlus and Aspen HYSYS. The process was analysed for different design conditions (temperature, autothermal condition, air flow, oxygen carrier flow) in the CLG process. It was found that in a typical pulp mill producing 800 000 adt per year, 375 kg- CO2/adt (14 % of total emissions from the process) can be inherently separated for storage to achieve negative emissions, if the multi-fuel boiler is replaced with a CLG unit. This process will also be able to generate 360-504 kWh/adt H2 depending on the design conditions in the CLG process. Heat recovered from the CLG unit can be utilized in capturing approximately 13 % additional CO2 from other sources in the pulp mill. Process analysis for different design conditions in CLG (temperature, airflow, oxygen carrier flow) have been presented. The key performance indicators were CO2 capture rates, H2 generated and net electrical output from the process.

Utveckling av en innovativ teknologi för koldioxidavskiljning med användning av aerosoldroppar av en kaliumkarbonatlösning. Laboratorieexperiment för att studera koldioxidabsorptionsprocessen under olika driftsförhållanden (temperatur, K2CO3- och CO2-koncentration, mängd genererad aerosol) / Development of an innovative technology for carbon capture using aerosol droplets of a potassium carbonate solution. Laboratory experiments to study CO2 absorption process with various operating conditions (temperature, K2CO3 and CO2 concentration, amount of aerosol generated)

Jordens befolkning behöver kraftigt reducera koldioxidutsläppen till atmosfären för att förhindra klimatförändringar. Klimatmål har sats upp av unioner och länder där de bland annat vill förhindra en global temperaturökning över 1.5 grader. För att uppnå dessa klimatmål menar forskare och institutioner på att stora mängder koldioxid kommer att behöva avskiljas vid utsläppskällor och lagras geologiskt (eng. carbon capture storage, förkortad CCS). I Sverige har ett fåtal CCS-projekt tagit fart men CCS är fortfarande inte kommersiellt tillgängligt. Frågeställningen för det här arbetet var därför: vilka är de mest relevanta utmaningar som kommersiellt tillgänglig CCS står inför idag i Sverige?Metoderna som användes var en litteraturstudie och tre\newline intervjuer. Personerna som intervjuades var en forskare från Chalmers Tekniska högskola, en chef från företaget Stockholm Exergi och en civilingenjör från projektet Northern lights. Utmaningarna delades in i kategorierna: tekniska-, politiska-, ekonomiska- och övriga utmaningar, för att enklare identifieras och jämföras. Resultaten visade att det fanns utmaningar i samtliga kategorier. Den tekniska utmaningen låg framförallt i att bygga upp och anpassa den tillgängliga CCS-tekniken till olika tillämpningsbara industrier. Politiskt var utmaningen främst att övertyga politiker att satsa på CCS, men också att införskaffa tillräckligt stora ekonomiska styrmedel, incitament och investeringar. Detta eftersom de som existerar idag antingen saknades helt eller ansågs vara för små. De ekonomiska utmaningarna var att stimulera investerare samt att bygga upp en fungerande och hållbar ekonomisk plan för CCS. I kategorin övriga utmaningar var den främsta utmaningen att övertyga befolkningen och att sprida kunskap kring CCS och dess potential. Avgränsningar i det här arbetet var framförallt bristen på resurser och tid. Fler intervjuer och en djupare litteraturstudie hade varit önskvärd för att fördjupa studien men begränsades av tid och möjligheter för kursens omfattning. / The world population need to reduce its carbon dioxide emissions to the atmosphere in order to prevent a climate change. Climate targets have been set by unions and countries to reduce carbon dioxide emissions before the average temperature rise exceeds 1.5 degrees Celsius. To achieve these climate goals, researchers and institutions believe large amounts of carbon dioxide needs to be stored below ground (carbon capture storage, abbreviated CCS). In Sweden have a small number of projects taken off, but CCS is still not commercially available. The question for this work was therefore: what are the most relevant challenges that commercially CCS currently faces in Sweden?The methods used were a literature study and three interviews.The persons interviewed were a researcher from Chalmers Tekniska university, a manager from the company Stockholm Exergi and an engineer from the Northern Lights project. The challenges were divided into four categories: technical-, political-, economic-, and other challenges, to make it easier to identify and compare. Results showed that there were challenges in all four categories. The technical challenge was mainly to build and adapt the available CCS technology to different types of industries. Politically, the challenge was primarily to increase their interest and support towards CCS. This along with the challenge of acquiring financial instruments, incentives and investments that was currently lacking or was too small. The economic challenges were to stimulate investors from both private and political quarters and to organize and operate a functioning and sustainable financial plan. In the category other challenges, the most mentioned challenge was convincing the population and to spread knowledge about CCS and its potential. Delimitations in this work was above all the lack of resources and time. More interviews anda deeper literature study would have been desirable to deepen the study but was limited by time and opportunities for the scope of the course.

Utsläpp av CO2 till atmosfären bidrar till ökningen av globala temperaturer. Industrisektorn står för 20 % av utsläppen och utav dessa kommer 6 % från pappers- och massaindustrin. För att lyckas minska den globala temperaturhöjningen till under 1,5 °C hjälper det inte bara att minska utsläppen. Även negativa utsläpp måste genereras. Syftet med denna studie är att undersöka implementeringen av CLG för att separera CO2 på ett energieffektivt sätt och samtidigt generera H2 och elektricitet. Processanalyser genomfördes för att undersöka möjligheten att implementera CLG-processen till ett typiskt massabruk. Processmodeller togs fram for att undersöka CLG, värmeåtervinning samt elektricitetsgenerering. Processmodellerna utvecklades med hjälp av Aspen Plus och Aspen HYSYS. De framtagna modellerna analyserades sedan med avseende på olika designparametrar inom CLG-processen. På ett typiskt massabruk som producerar 800 000 adt varje ˚ar kan 375 kg CO2/adt separeras och då uppnå negativa utsläpp, genom att byta ut multi-fuel forsrännaren med en CLG process. Den framtagna processmodellen skulle också kunna generera 360-504 kWh/adt av H2 beroende på de designparametrar som används för CLG-processen. Enligt modellen kan värme som ˚återvinns från processen användas för att fånga upp ytterligare 13 % av CO2 från andra delar av bruket. Processanalys för olika designparametrar inom CLG systemet så som temperatur, luftflöde och flödet av syrgasbärare har presenterats. Nyckeltalen som undersöktes var den mängd CO2 som kunde fångas upp, mängd H2 genererad samt överskottet av elektricitet som produceras när multi-fuel förbränningen byts ut mot en CLG-process på ett typiskt massa bruk. / Emissions of CO2 to the atmosphere are contributing to the global temperature rise. The industrial sector contributed to 20 % of the emissions and out of that, 6 % are generated from the pulp and paper industry. To limit the temperature increase below 1,5 °C, the emissions not only need to be reduced but also negative emissions should be generated from different sectors. The purpose of this study is to realize the implementation of Chemical Looping Gasification (CLG) to separate CO2 (for permanent storage) in an energy-efficient way while co-generating H2 as well as electricity. Process analysis was carried out to investigate the possibility of substituting the multifuel boiler in a typical pulp mill with a CLG process. Process models for the CLG, heat recovery and electricity generation process were developed using Aspen  Plus and Aspen HYSYS. The process was analysed for different design conditions (temperature, autothermal condition, air flow, oxygen carrier flow) in the CLG process. It was found that in a typical pulp mill producing 800 000 adt per year, 375 kg- CO2/adt (14 % of total emissions from the process) can be inherently separated for storage to achieve negative emissions, if the multi-fuel boiler is replaced with a CLG unit. This process will also be able to generate 360-504 kWh/adt H2 depending on the design conditions in the CLG process. Heat recovered from the CLG unit can be utilized in capturing approximately 13 % additional CO2 from other sources in the pulp mill. Process analysis for different design conditions in CLG (temperature, airflow, oxygen carrier flow) have been presented. The key performance indicators were CO2 capture rates, H2 generated and net electrical output from the process.

It is known that the decarbonization of our economy is crucial for our quest to mitigate climate change and build a sustainable society. Governments are reviewing strategies to eliminate, or at least minimize, the release of carbon emissions into the atmosphere. These efforts are not limited to national energy networks, but also extended to industry and other carbon-intensive sectors. In general, the Pulp & Paper industry is regarded as bio-based and relatively sustainable since most of its raw materials are recycled or come from biogenic sources. However, this is an energy-intensive industry, and even though bioenergy covers most of the energy needs at pulp plants, recycled paper mills do not count on the same resources and rely heavily on fossil fuels to power their operations. This study was performed to assess and compare different decarbonization pathways available for a recycled paper mill. For this, operational data was gathered to characterize the thermal and electric demands and assess locally available resources. Simultaneously, scientific literature was consulted to assemble a technology portfolio, from which the most suitable technologies were selected. Carbon capture and storage, electrification, and hydrogen were chosen to be tested, under different scenarios, using an energy modelling software. Finally, the combinations were evaluated and compared. It was found that under ideal conditions it is possible to achieve an emissions reduction of almost 100% via electrification and hydrogen-based options. However, this would represent a significant increase in the operating cost of the energy system and would depend on the development of the necessary infrastructure. The most promising alternative for this site was a combination of electrification and green electricity purchase agreements. However, further work is needed to improve the efficiency of the energy use and generation, to achieve a carbon-neutral operation without incurring elevated costs. / Det är känt att avkarboniseringen av vår ekonomi är avgörande för vår strävan att mildra klimatförändringarna och bygga ett hållbart samhälle. Regeringar ser över strategier för att eliminera, eller åtminstone minimera, utsläpp av koldioxid i atmosfären. Dessa ansträngningar är inte begränsade till nationella energinät, utan sträcker sig även till industrin och andra kolintensiva sektorer. Massa- och pappersindustrin är biobaserad och relativt hållbar eftersom de flesta av dess råvaror återvinns eller kommer från biogena källor. Detta är dock en energiintensiv industri, och även om bioenergin täcker det mesta av energibehovet vid massafabrikerna, räknar inte återvunnet pappersbruk med samma resurser som är starkt beroende av fossila bränslen för att driva sin verksamhet. Denna studie utfördes för att bedöma och jämföra olika avkolningsvägar tillgängliga för ett återvunnet pappersbruk. För detta samlades operativa data in för att karakterisera de termiska och elektriska kraven och bedöma lokalt tillgängliga resurser. Samtidigt konsulterades vetenskaplig litteratur för att sammanställa en teknologiportfölj, från vilken de mest lämpliga teknologierna valdes ut. Kolavskiljning och lagring, elektrifiering och väte valdes ut för att testas, under olika scenarier, med hjälp av en mjukvara för energimodellering. Slutligen utvärderades och jämfördes kombinationerna. Man, fann att det under ideala förhållanden är möjligt att uppnå en utsläppsminskning på nästan 100 % via elektrifiering och vätebaserade alternativ. Detta skulle dock innebära en betydande ökning av driftskostnaden för energisystemet och skulle bero på utvecklingen av den nödvändiga infrastrukturen. Det mest lovande alternativet för denna plats var en kombination av elektrifiering och köp av grön el. Det krävs dock ytterligare arbete för att effektivisera energianvändningen och energiproduktionen, för att uppnå en koldioxidneutral drift utan förhöjda kostnader.

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.