No description available.

The Paris Agreement has ambitious targets to limit the global warming below 1.5 °Cin the 21st century. This goal is reflected in the national climate targets, for example, Sweden aims to achieve net zero greenhouse gas emissions by 2045, and thereafter achieve negative emissions. One of the pivotal ways to achieve these goals is by applying the mature bioenergy with carbon capture and storage (BECCS) technology to large-scale industries that emit CO2. Around 6% of the global emissions arise from the pulp and paper industry making them one of the largest localized emitters of biogenic CO2. This makes them suitable for retrofitting BECCS technologies and post-combustion capture (PCC) is one among them. This study presents a techno-economic assessment of an absorption-based PCC unit in SCA Östrand pulp mill. Chemical absorption using MEA and chilled ammonia process (CAP) using NH3 as the solvent are considered in this study. For both the processes, mass and energy balances using Aspen HYSYS were done and validated against published data in literature. Heat integration by applying excess or waste heat from the mill is also considered in this work. CO2 capture from flue gas originating from various emission sources in the mill (recovery boiler, lime kiln and multi-fuel boiler) are considered in different combinations in the analysis. The main key performance indicator (KPI) evaluated in this work is the cost of CO2capture for all the different cases for both the MEA- and chilled NH3-based absorption processes. The minimum cost of CO2 capture for MEA-based absorption process was found to be in the range 37-41 €/tCO2 and for CAP, it was found to be in the range 73-81 €/tCO2. For MEA-based absorption process, the excess low pressure steam from the mill satisfies the steam demand in all the cases, except the one where CO2 is captured from all the three emission sources. For CAP, sufficient excess low pressure steam is present in the mill for all the capture cases due to a lower reboiler duty compared to MEA-based absorption process. An optimal process configuration and capture scenario for the existing design conditions in the mill are derived and justified. A sensitivity analysis was carried out to find the associated bottlenecks from the breakdown of the cost of CO2 capture for each process. The overall BECCS cost is also sensitive to CO2 transport & storage costs. However, it is also clear that incentives for negative emissions will make BECCS an attractive solution for the pulp and paper industry.

Due to the increasing climate change concerns, biofuels have attracted more attention in the energy field as potential alternative energy sources. Particularly, microalgal biofuel has stood out because of its higher fuel yield potential and lower water and land demand than terrestrial biomass. Because of its outstanding photosynthetic efficiency, the microalgal technology is also investigated by researchers around the world as a potential biological solution for carbon capturing in the industrial sector. To explore the prospects of microalgal technology in a local context, this research lays it focus on investigating the potentiality of microalgal biofuel in the cement industry on Gotland, which is the largest emitter of greenhouse gases on the island. For this purpose, the thesis implements a series of estimations based on the emission data of Cementa AB, Slite, a picture of the potential production of algal biomass and biofuel was created, followed by comparisons to the energy situation on Gotland. While practical data of the selected microalgae species are presented, the results indicate a high potential of microalgae in the production of algal biofuel and the possibility for algal biofuel to power the industrial sector of Gotland, or even the island entirely. Although the estimations are made based on an assumption where all controlling parameters are assumed to be perfectly manipulated, the results still indicate the significance of microalgal technologies in the near-future bioeconomy and global energy system.

Accelerated carbonation is a new CO2 storage method under development as a solution for climate change caused by anthropogenic activities. In accelerated carbonation an alkaline source such as minerals or industrial residues react with carbon dioxide in a presence of slightly acidic solution to produce stable solid carbonates. There are varieties of accelerated carbonation routes which differ in process condition.</p><p>The aim of this study was to evaluate and compare the potential of a slurry route process and a wet route process for the carbonation of basic oxygen furnace (BOF) slag using the CO2 emitted by a conventional natural gas power plant.</p><p>For this purpose a life cycle assessment (LCA) study was performed based on principles and guidelines provided by ISO 14040:2006 and routines and data provided by the SimaPro v8 software package. The material and energy requirements for each of the steps involved in the carbonation process, i.e. pre-treatment of raw material, CO2 compression, transportation, carbonation step, after-treatment and landfill, were calculated and included in the LCA study.</p><p>The slurry and wet route resulted in net CO2 reduction of 87.4% and 72.3% respectively.  However, a positive contribution to other environmental issues was observed with the wet route leading to higher impact mainly due to high heating requirement. An exception was contribution of slurry route to abiotic resource depletion, which was higher for the slurry route due to high water requirement. A general conclusion was that the electricity consumption is the main cause of environmental issues. Sensitivity analyses showed that the environmental impacts are dependent on the transportation distance and electricity source, while no dependence was observed with respect to construction of the carbonation plant.

Carbon dioxide from biogas production is currently considered to be without value and isbecause of this released into the atmosphere in the biogas upgrading process. The residualgas is a potential carbon source and can create value in the biogas manufacturing process.By finding a suitable value-creating process that utilizes carbon dioxide, it can be possibleto provide both economic and environmental incentives for companies to develop theiroperations. This project explored the possibility to create value from this CO2. Through anevaluation of the technical maturity of CCU technologies, a recommendation could be givenat the end of the project. An analysis of technical barriers, such as pollutants in the gas, aswell as barriers in the form of competence and corporate culture were examined in orderto provide a reasoned recommendation. The project mapped which value-creating systemswould be suitable for biogas producers in a Swedish context. This included established methaneand carbon dioxide upgrading techniques currently in use and suitable CCU techniquesthat can interact with the selected upgrading processes and serve as value creators. Based onthis survey, it was then possible to identify common, critical variables for these systems. Thereafter,a recommendation of an appropriate CCU technology could be given depending onthe CO2 composition produced. One conclusion from the study was that carbon dioxide concentrationsfrom the residual gas was often high (approx. 97-98 %) and did not contain anycorrosive or toxic components, and that this largely depends on how the digestion reactor ishandled in the production process. Thus, questions were raised about what the actual limitationsof the CCU are, as they did not seem to be technical. CCU techniques that proved to beof particular interest were pH regulation of sewage plants, CO2 as a nutrient substrate for thecultivation of microalgae, and manufacturing of dry-ice for refrigerated transports. All of thesetechnologies currently have a sufficiently high degree of technical maturity to be installedalready today. Other CCU techniques, such as "’Power to gas”, require a high CO2 concentrationand were discarded as the literature review did not suggest the economic potential forthem as they require additional CO2 upgrading steps. Instead, CCU techniques were chosenthat could be implemented directly with the existing CO2 quality. Furthermore, it was concludedthat one reason why CCU technologies have not been widely implemented is internalbarriers between distributors and manufacturers (or users) of CCU technologies. Thus, theuse of carbon dioxide from biogas production and implementation of CCU technologies canbe promoted by eliminating barriers in companies, such as a lack of both knowledge andfinancial incentives. / Koldioxid från biogasproduktion betraktas i dagsläget som utan värde och släpps ut i atmosfärenvid uppgradering av biogas. Restgasen är en potentiell kolkälla och kan vara värdeskapandeför biogasprocessen. Genom att finna en lämplig värdeskapande process som utnyttjarkoldioxid går det att ge både ekonomiska och miljömässiga incitament till företag att utvecklasin verksamhet. I detta projekt undersöktes möjligheten att skapa värde av denna CO2.Genom en utvärdering av den tekniska mognadsgraden hos CCU-tekniker kunde en rekommendationges vid projektets slut. En analys av tekniska hinder, såsom föroreningar i gassammansättningen,såväl som hinder i form av kompetens och företagskultur undersöktes för attkunna ge en motiverad rekommendation. I projektet kartlades vilka värdeskapande systemsom skulle passa för biogasproducenter i en svensk kontext. Detta inkluderade etableradeuppgraderingstekniker för metan- och koldioxid som används i dagsläget. I projektet undersöktesäven lämpliga CCU-tekniker som kan samverka med de valda uppgraderingsprocessernaoch och agera värdeskapande. Utifrån denna kartläggning kunde det sedan anges vilkagemensamma, kritiska variabler som finns för dessa system. Därefter kunde en rekommendationav lämplig CCU-teknik ges beroende på den producerade CO2 sammansättningen. Enslutsats i projektet var att koldioxid från restgasen ofta var av hög koncentration (ca. 97-98 %)och ej innehöll några korrosiva eller toxiska komponenter, och att detta till stor del beror påhur rötkammaren är hanterad i produktionsprocessen. Således väcktes frågor kring vilka defaktiska begränsningarna för CCU är, då de inte torde vara tekniska. CCU-tekniker som visadesig vara av särskilt intresse var pH-reglering av avloppsverk, CO2 som näringssubstratför odling av mikroalger, samt tillverkning av kolsyreis för kyltransporter. Samtliga dessatekniker har tillräckligt hög teknisk mognadsgrad för att kunna installeras i dagsläget. AndraCCU-tekniker, såsom ”Power to gas”, kräver en hög CO2-koncentration och avfärdades dålitteraturstudien inte talade för den ekonomiska potentialen i dessa eftersom de kräver ytterligareuppgraderingssteg för CO2. Således valdes istället CCU-tekniker som skulle gå attimplementera direkt med den befintliga CO2 kvalitén. Vidare drogs slutsatsen att en anledningtill att CCU-tekniker inte har blivit vida implementerade till stor del är interna hindermellan distributörer och tillverkare (eller utnyttjare) av CCU-tekniker. Således kan användandetav koldioxid från biogasproduktion och implementering av CCU-tekniker främjasgenom att eliminera hinder hos företag. I projektet yttrade sig detta som bristande ekonomiskaincitament och okunskap. Ett ökat användande av CCU-tekniker kan också uppnås genomatt införa lagar och regler som begränsar användandet av föråldrade tekniker som drivs avfossila bränslen, och som kan ersättas av klimatvänliga CCU-tekniker.

Global CO2 emissions produced by energy-related processes, mainly power plants, have increased rapidly in recent decades; and are widely accepted as the dominant contributor to the greenhouse gas (GHG) effect and consequent climate changes. Among countermeasures against the emissions, CO2 capture and storage (CCS) is receiving much attention. Capture of CO2 is the core step of CCS as it contributes around 75% of the overall cost, and may increase the production costs of electricity by over 50%. The reduction in capture costs is one of the most challenging issues in application of CCS to the energy industry. Using limestone in CaO-looping cycles is a promising capture technology to provide a cost-effective separation process to remove CO2 content from power plants operations. Limestone has the advantage of being relatively abundant and cheap, and that has already been widely used as a sorbent for sulphur capture. However, this technology suffers from a critical challenge caused by the decay in the sorbent capture capacity during cyclic carbonation/calcination, which results in the need for more sorbent make-up; hence a reduction in cost efficiency of the technology. The performance of sorbent influenced by several operating and reaction conditions. Therefore, much research involves investigation of influencing factors and different methods to reduce the sorbent deactivation. Cont/d.

This study provides independent analysis of Residual Oil Zones (ROZs) in the Permian Basin from a regional perspective, focusing on the formation mechanism and present ROZ locations. Results demonstrate widespread potential for ROZs, defined here as thick volumes of reservoir rock containing near-residual saturations of predominantly immobile oil formed by natural imbibition and displacement of oil by dynamic buoyant or hydrodynamic forces. Previous work suggests hydrodynamic forces generated by regional tectonic uplift drove widespread oil remobilization and ROZ creation. To test the hypothesis, uplift and tilting are quantified and the resulting peak regional potentiometric gradient used as a physical constraint to compute and compare predicted ROZ thicknesses from hydrodynamics for several ROZ-bearing San Andres fields with known ROZ thicknesses. Late-Albian Edwards Group geologic contacts, which are interpreted to have been deposited near sea level prior to uplift, are used as a regional datum. Approximate elevations determined for the present datum show ~1800 m of differential uplift since Edwards deposition, with an average regional slope of ~0.128˚. This post-Edwards tilting increased the pre-existing regional structural gradient of the San Andres Formation to ~0.289˚. Using the calculated post-Edwards gradient results in to prediction of ROZ thicknesses from hydrodynamics that is consistent with measured ROZ thicknesses at several fields. When compared with countervailing buoyancy forces, hydrodynamics is calculated to be the more dominant driving force of oil movement for reservoirs with structural dips less than 1.5˚, which is the common dip for San Andres Formation platform deposits where ROZs have been identified. To predict the location of ROZs, ROZ-related oil field properties were identified and analyzed for over 2,800 Permian Basin reservoirs. A strong basin-wide correlation between API and crude sulfur content is consistent with the expected outcome of oil degradation driven by oil-water interaction, and supports the use of API and sulfur content as proxies for ROZ potential in the Permian Basin. Spatial analysis of sulfur data shows that the highest probability for ROZ existence exists in Leonardian through Guadalupian-age reservoirs, distributed primarily in shelf and platform areas of Permian structures. Combined, these results support the widespread potential for ROZs across the Permian Basin generated primarily by regional scale tilting and resultant hydrodynamic forces. / text

La conversion de la biomasse en énergie génère des flux de gaz carbonique qui peuvent être captés,transportés puis stockés dans des strates géologiques. Ce procédé, nommé BCCS (Biomass Carbon Captureand Storage), réduit drastiquement les émissions carbonées et dans certaines conditions le puits artificiel peutstocker plus de carbone que le système de conversion n’en aura produit (émissions négatives). Ainsi, le BCCSrend plus envisageable l’obtention de certains plafonds de concentrations de CO2 atmosphériques inférieurs ouégaux à 450ppm. Des incitations économiques sont nécessaires pour déclencher l’investissement dans leBCCS de la part d’acteurs du secteur privé. Ceux-ci sont confrontés à une incertitude de grande ampleurconcernant le prix du carbone. Nous étudions dans cette thèse le comportement d’un décideur ayant le choixd’investir dans une variante du BCCS, à savoir la production de bioéthanol à partir de betteraves sucrières.Après une analyse déterministe sur un cas réel, nous étudions l’influence de différentes incertitudes sur le profild’investissement via une approche par options réelles. Nous analysons notamment l’influence de l’incertitudedu progrès technique via une loi de Poisson et montrons que l’investisseur tend à attendre l’innovation. Nousdistinguons ensuite progrès de court terme et de long terme. Puis, nous nous intéressons à l’incertitude derégulation climatique. Le marché du carbone est alors modélisé par un mouvement de retour à la moyenneavec des sauts de prix à dates fixes / Using biomass to produce energy emits carbon dioxide. These emissions can be captured, transported andstored into geological formations. This process is named BCCS (Biomass Carbon Capture and Storage). Itleads to massive reductions and the whole system carbon balance system could be negative given specificassumptions, which is called ‘negative emissions’. BCCS may help to achieve low CO2 concentration target,even below the 450ppm threshold. Providing suitable incentives is necessary to trigger private investment.Private investors are facing considerable uncertainty, about the carbon market. We study in this dissertation thebehavior of decision makers who can invest in a specific variant of BCCS, which is the production ofbioethanol coming from sugar beets. After a deterministic analysis based on a real case study, we consider theinfluence of different kinds of uncertainties on the investment profile through a real option approach. Thetechnical progress uncertainty has been modeled with Poisson jumps. We show that investors tend to wait forinnovations. We distinguish two cases depending on the progress rate: early or delayed technical progressrate. First allowance price is driven by geometric Brownian motion. Second, the price follows a mean revertingprocess with jumps at specific fixed dates, to take into account the international round of negotiations aboutclimatic change, as a kind of climate regulation uncertainty.

Políticas de mudanças climáticas estabeleceram diversas metas de redução de gases de efeito estufa (GEE) que estão vigentes atualmente. Dentre estas, a 21º Conferência das Partes realizada pela Convenção-Quadro das Nações Unidas sobre Mudança do Clima (em Paris, 2015) foi um marco na universalização dos esforços internacionais, e promoveu o protagonismo regional como suporte ao alcance das metas propostas nas contribuições nacionalmente determinadas. No Estado de São Paulo, diferentemente do quadro nacional, o setor de energia representa mais da metade do saldo total de emissões de GEE. Estudos de baixo carbono para o setor energético têm proposto cenários audaciosos, baseados em tecnologias não plenamente maduras e alta demanda por fontes renováveis. O presente trabalho propõe uma abordagem alternativa visando a mitigação das emissões de GEE, além de analisar os impactos na demanda energética total do Estado, até o presente não analisada na sua totalidade no âmbito regional. O objetivo do estudo foi produzir dois cenários de baixo carbono para o setor energético do Estado de São Paulo até 2050. O primeiro cenário (CBC1) buscou averiguar se é possível cumprir as metas de redução por uma ótica conservadora. O segundo cenário (CBC2), de caráter exploratório, visou ser mais audacioso em relação ao CBC1, tomando medidas radicais para atingir o máximo resultado de mitigação. O cenário de referência (BAU) teve como base a demanda energética final em 2015, projetada até 2050 através do Plano Decenal de Expansão de Energia. As tecnologias de baixo carbono no CBC1 foram levantadas na base de metodologias provadas para o Mecanismo de Desenvolvimento Limpo (MDL), e expandidas para o CBC2 com base em uma revisão da literatura. No CBC1, as três medidas de mitigação propostas seriam capazes de reduzir 16% das emissões totais do cenário BAU no período de análise, entretanto as emissões continuariam no mínimo 19% acima da emissão do setor no ano base de 2005. Por outro lado, o CBC2 possui seis medidas capazes de reduzir 69% das emissões do cenário BAU e, a partir de 2044, as emissões líquidas são negativas, disponibilizando aos demais setores 5% da mitigação total até 2050. A implantação do baixo carbono também reduz a demanda total energética em até 2% no ano final, entretanto há demandas específicas, como a de biodiesel, que são consideravelmente aumentadas. O trabalho discute os resultados à luz da literatura e apresenta as principais barreiras impostas aos cenários propostos, assim como as incertezas e limitações da análise. Além disto, contribui metodologicamente para que futuros estudos possam avaliar a possibilidade de cumprimento de metas de redução em outras regiões ou setores da economia, considerando uma ótica conservadora baseada no MDL / Climate change policies have established several greenhouse gas (GHG) reduction targets. Among them, the 21st Conference of the Parties of the United Nation Framework Convention on Climate Change (held in Paris in 2015) was a milestone for the universalization of international efforts, and the promotion of a regional activism in supporting to the goals proposed by the national determined contributions. In the State of Sao Paulo, in opposition to the national profile, the energy sector represents more than half of the total GHG emissions. Low carbon studies for the energy sector have proposed audacious scenarios based on not yet mature technologies and high renewable energy demand. The present work proposes an alternative GHG mitigation approach, and in addition it analyzes the impacts on Sao Paulos total energy demand, which was not yet entirely analyzed by other regional studies. The study has aimed to produce two low carbon scenarios for State of Sao Paulos energy sector by 2050. The first scenario (LCS1) attempted to verify whether GHG reduction targets can be reached by a conservative approach. The second scenario (LCS2) is exploratory and has aimed to be more audacious than LCS2, through radical measures aiming to the maximum mitigation result. The business-as-usual (BAU) scenario has been based on the States final energy demand, beginning in 2015 and forecasted until 2050 with data from the Decennial Energy Expansion Plan. Low carbon technologies for LCS1 have been selected among the Clean Development Mechanism (CDM) proven methodologies. The framework has been expanded for LCS2 based on a literature review. On the one hand, three measures proposed in LCS1 would be able to reduce 16% of BAU total emission in the analyzed period; however, emissions remain at least 19% above 2005 baseline emission. On the other hand, LCS2 has six measures able to reduce 69% of BAU total emissions and, from 2044; net emissions would be negative, which enables 5% of total mitigation for other sectors by 2050. The low carbon implementation also reduces total energy up to 2% in the 2050, although there are specific demands, such as biodiesel, that will significantly increase. The work discusses the results vis-à-vis the literature and presents the main barriers imposed to low carbon scenarios, as well as uncertainties and limitations of the analysis. Moreover, it methodologically contributes to future studies that may assess the potential of a conservative approach based on CDM, regarding other regional and sectorial contexts

A captura e uso do dióxido de carbono é uma das formas de ajudar a frear as emissões de gases do efeito estufa (GEE) e destiná-lo a um fim útil. Um possível uso para o CO2 seria como fertilizante agrícola, uma vez que as plantas quando em maiores concentrações deste gás ceteris paribus apresentam um incremento de biomassa. Os biocombustíveis são opções que contribuem para a mitigação das mudanças climáticas em detrimento ao uso de combustíveis fósseis e entre os biocombustíveis a produção de etanol a partir de cana-de-açúcar se destaca devido a vantagens quanto à emissão de GEE e energia acumulada. Essas vantagens podem ser ainda maiores com o uso do CO2 proveniente de suas biorrefinarias na forma de insumo agrícola. O objetivo deste trabalho é avaliar esta nova técnica de uso de carbono por meio da metodologia da Avaliação do Ciclo de Vida (ACV) e da pegada de carbono de produtos para encontrar suas contribuições no balanço de energia e carbono do sistema. Um modelo de dispersão de gases foi utilizado para saber se é possível manter a concentração de CO2 no campo dentro dos parâmetros necessários para o incremento de biomassa. A análise indica que um sistema adaptado de irrigação por gotejamento pode manter a concentração deste gás dentro do nível desejado quando a emissão fica em 22,5 g ha-1s-1, mas que uma mesma área não é autossuficiente para o fornecimento de CO2 para fase de crescimento dos colmos. Através da ACV e da pegada de carbono da cana-de-açúcar em um cenário onde o incremento de biomassa é médio em relação aos experimentos encontrados, a tecnologia reduz em 13,5% a demanda de energia e 11,8% as emissões de GEE por MJ de bioenergia produzida se comparada ao sistema tradicional. O balanço de energia para o sistema tradicional e com reciclagem de CO2 foi de 170 GJ/ha e 206 GJ/ha, enquanto o balanço de carbono foi de -13950 kgCO2eq/ha e -17019 kgCO2eq/ha, respectivamente. Considerando as possíveis variações de incremento de biomassa, para cada MJ produzido a emissão de GEE pode variar em 8,9% e o consumo de energia em 10,9%. Essa nova técnica de uso de carbono do ponto vista teórico pode ser aplicada em campo e implica em um aumento entre 13 a 30% do balanço de energia para um hectare de cana-de-açúcar, consequentemente uma menor quantidade de terra será necessária para atingir as metas energéticas estipuladas / Carbon capture and use (CCU) may slow down greenhouse gas (GHG) emissions and direct them to a useful end. A possible CO2 application is as plant fertilizer because ceteris paribus biomass increases when plants grow under high CO2 concentrations. Compared to fossil fuels, biofuels mitigate climate change, and the use of sugarcane ethanol stands out due to its low lifecycle GHG emissions and Cumulative Energy Demand (CED). Such benefits might be enhanced with the use of CO2 from the biorefinery as a crop fertilizer. The objective of this study is evaluating this new CCU scheme based on a life cycle assessment (LCA) and a carbon footprint to determine its energy and carbon balances. An air pollution dispersion model was used to verify whether it is possible to maintain the CO2 concentration on the field so that biomass increase takes place. The analysis demonstrates that a drip irrigation system can keep the concentration of gas within the desired level when the emission is 22.5 g ha-1s-1, but that the same area is not self sufficient to supply CO2 for the complete growth phase of the stalks. Results from the LCA and the carbon footprint demonstrate that compared to the traditional system, the scheme decreases CED and GHG emissions by 13,5% and 11,8%, respectively. The energy balance of the traditional and the recycling system were 170 GJ/ha and 206 GJ/ha, respectively, whereas the carbon balance was -13,950 kgCO2eq/ha and -17,019 kgCO2eq/ha, respectively. Considering the range of growth responses, for each MJ produced GHG emissions vary 8,9% whereas energy consumption varies 10,9%. These CCU scheme might be applied on the field and implies in improvements between 13 and 30% in the energy balance of 1ha of sugarcane; thus, a smaller land area will be needed than with the traditional system to achieve the energy goals