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Att begränsa globala uppvärmningen till 1,5°C kommer kräva negativa koldioxidutsläpp. En metod för att generera negativa koldioxidutsläpp är så kallad Bio-Energy Carbon Capture and Storage (BECCS). En direkt implementering av BECCS är att fånga in CO2 från rökgas som genereras vid förbränning av biomassa i en så kallad post-combustion capture-konfigurering. Post-combustion BECCS har skapat en stor resonans hos kraftverksoperatörer och pappersproducenter. Stockholm Exergi, som ägs av Fortum och Stockholms Stad, siktar på att fånga in upp till 800 kt CO2 per år från deras biomass-eldade CHP-anläggning i Värtaverket vid 2024. Planen är att fånga in CO2 från rökgasen genom en absorptionsprocess och sedan skeppa det till Norge för geologisk förvaring. Mastersexamensarbetet följde en experimentskampanj driven av Stockholm Exergi som siktade på att uppnå experimentell validering av en absorptionsprocess för koldioxidinfångning från rökgas vid förbränning av biomassa. En testenhet konstruerades och tester genomfördes från december 2019 till maj 2020. Examensarbetet fokuserade på rollen absorptionsmedlet hade på infångningshastigheten. Tester med tre olika lösningsmedel genomfördes och de experimentella resultaten analyserades genom en kombination av jämviktsmodeller och Murphree-effektiviteter. Resultatet visar att ett absorptionsmedel baserat på vattenlöslig K2CO3 är kompatibel med rökgas från förbränning av biomassa, eftersom infångningshastigheter mellan 5 och 13 % uppmättes. De undersökta hastighetspromotorerna (3 vikt% H3BO3 + 1 vikt% V2O5) visade dock inte den förväntade effekten på infångningshastigheter, och på grund av tidsbegränsningar testades inte olika vikt% av promotorn under det här examensarbetet. Ingen tydlig slutsats drogs därför med hänsyn till promotorer. Baserat på Murphree-effektiviteterna som beräknats genom experimenten med konstant förhållande mellan vätske- och gasflöde uppskattas en 28–35 m hög kolonn fånga 90% av CO2 i rökgasen. / Limiting global warming to 1.5°C will require negative carbon emissions. One way for generating negative carbon emissions is through bio-energy carbon capture and storage (BECCS). A direct implementation of BECCS is to capture CO2 from the flue gas originating from the combustion of biomass in a post-combustion capture configuration. Post-combustion BECCS has generated considerable resonance among power plant operators and paper manufactures. Stockholm Exergi, owned by Fortum and Stockholm Stad, aims at capturing up to 800 kt CO2 per year from their biomass-fired CHP plant in Värtaverket by 2024. The plan foresees to capture CO2 from the flue gas utilizing an absorption process and shipment of the captured CO2 to Norway for geological storage. The Master thesis project followed an experimental campaign run by Stockholm Exergi that aimed at experimental validation of an absorption process for carbon capture from flue gas originating from the combustion of biomass. A test unit was constructed, and test trials were run from Dec. 2019 to May 2020. The thesis focused on the role of the absorption solvent on the capture rate. Test trails with three different solvents were conducted, and the experimental results were analyzed using equilibrium models combined with Murphree efficiencies. The results show that an absorption solvent based on aqueous K2CO3 is compatible with the flue gas derived from biomass combustion, i.e., capture rates ranging from 5 to 13 % were measured. However, the investigated rate promoters (3 wt.% H3BO3 + 1 wt.% V2O5) did not show the expected effect with regards to capture rates and due to time constrain different wt.% of the promoter were not tested within the scope of this thesis. Therefore, no firm conclusion was given with regards to promoters. Based on the Murphree efficiency calculated from the experiment with keeping a constant liquid to gas flow ratio, a column height of 28-35 m is estimated to capture 90% of CO2 from the flue gas.

A catalytic route to hydrogen production via thermochemical water splitting is highly desirable because it directly converts thermal energy into stored chemical energy in the form of hydrogen and oxygen. Recently, the Davis group at Caltech reported an innovative low-temperature (max 850°C) catalytic cycle for thermochemical water splitting based on sodium and manganese oxides (Xu, Bhawe and Davis, PNAS, 2012). The key steps are thought to be hydrogen evolution from a Na₂CO₃/MnO mixture, and oxygen evolution by thermal reduction of solids formed by Na⁺ extraction from NaMnO₂. Our work is aimed at understanding the fundamental chemical processes involved in the catalytic cycle, especially the hydrogen evolution from water. In this project, efforts are made to understand the interactions between the key components (Na, O₂, CO₂, and water) in the hydrogen evolution steps on a well-defined MnO(100) single crystal surface, utilizing x-ray photoelectron spectroscopy (XPS), low energy electron diffraction (LEED) and temperature programmed desorption (TPD). While some of the behavior of the catalytic system is observed with the model system developed in this work, hydrogen is only produced from water in the presence of metallic sodium, in contrast to the proposal of Xu et al. that water splitting occurs from the reaction of water with a mixture of Na₂CO₃ and MnO. These differences are discussed in light of the different operating conditions for the catalytic system and the surface science model developed in this work. / Ph. D.

Cette méta-analyse révise et accroit le corpus de données d’analyses de la teneur isotopique du collagène osseux (δ 13C et δ 15N) et du carbonate des os et de l’émail dentaire (δ 13C et δ 18O) mesuré sur quatre collections ostéologiques canadiennes, afin d’étudier l’identité culturelle et l’adaptation alimentaire dans la vallée du Saint-Laurent, du XVIIe au XIXe siècle. Ces sites correspondent aux trois gouvernements de la colonie du Canada : le Vieux Cimetière de Trois-Rivières (1650-1865) et le cimetière de la première église paroissiale de Notre-Dame à Montréal (1691-1796), ouverts durant la période de la Nouvelle-France, et le cimetière Saint-Matthew à la ville de Québec (1771-1860) apparu au début du Régime Britannique. Le site de Sainte-Marie-de-Beauce (1748-1878) ajoute un comparatif, en contexte rural, à ces sites urbains. Dans un premier temps, la compilation des données démontre une incompatibilité entre les chercheurs en ce qui concerne les δ 15N du collagène et les δ 13C du carbonate osseux mesurés. Pour explorer la variation en δ 15N, l’effet de l’utilisation d’un agent acidifiant (acide chlorhydrique, HCl) a été testé, de même que la reproductibilité des résultats. Un enrichissement en 15N a été observé chez les échantillons traités avec du HCl à 2 % et 5 %. La variabilité des mesures entre les séquences d’analyses, malgré la constance de la mesure de l’étalon interne, n’a pu être expliquée. Dans un deuxième temps, la diversité culturelle des sites a été explorée. Par l’analyse des comportements migratoires et alimentaires à l’enfance (δ 18O et δ 13C de l’émail dentaire, respectivement), des « identités culturelles » ont été suggérées, soit : possiblement Autochtone, Inuit, Canadien Français ou Anglais, Nord-Américain (Acadien, Louisianais ou Terre-Neuvien), prisonniers de la Nouvelle-Angleterre, individu de descendance Africaine et Européen. L’hypothèse de la mise en esclavage de certains de ces individus, basée sur trois caractéristiques, le lieu d’origine, le décès avant l’âge de 17 ans et un changement drastique d’alimentation, a permis de considérer cet aspect de l’histoire canadienne. Dans un troisième temps et finalement, l’étude du carbonate des os (δ 13Ccarb) de même que du collagène osseux (δ 13Ccoll et δ 15N) a permis d’aborder l’adaptation alimentaire au Québec ancien. Globalement, les quatre sites suggèrent une rétention des traditions alimentaires Européennes (alimentation de type C3), tendance similaire à ce qui a été observé pour des sites coloniaux nord-américains, situés en contexte continental (tels que la Louisiane et l’Ontario). Les Canadiens français de Montréal semblent consommer plus de ressources C4 (telles que le maïs, la canne à sucre ou le rhum) que les migrants intracontinentaux (de l’Amérique du Nord tels que les Acadiens et Louisianais). Inversement, à Québec, les immigrants des Îles Britanniques ont consommé plus de ressources C4 que les individus nés localement. Comme les ressources marines étaient consommées par des individus à Montréal, une explication a été proposée en relation avec les restrictions alimentaires du calendrier liturgique Catholique. / This meta-analysis reviews and expands the dataset and analysis of bone collagen (δ 13C and δ 15N) and carbonate content of bone and tooth enamel (δ 13C and δ 18O) measured on four key sites, to study dietary adaptation in the St. Lawrence Valley from the 17th to the 19th centuries. These sites correspond to the three governments of the colony of Canada: The Old Cemetery of Trois-Rivières (1650-1865) and the cemetery of the first parish church of Notre-Dame in Montreal (1691-1796), both opened during the New France era, while the Saint-Matthew cemetery in Quebec City (1771-1860), belongs to the British Regime. The Sainte-Marie-de-Beauce cemetery (1748-1878) adds a rural comparison to these urban sites. Firstly, a compilation of the data demonstrated incompatibilities between some researchers concerning the bone collagen δ 15N and the bone carbonate δ 13C measured. The effect of various concentrations of an acidifying agent (hydrochloric acid, HCl) on δ 15N was tested, as was the reproducibility of the results. Enrichment in 15N was observed in samples treated with 2 % and 5 % HCl. The variability of measurements between analytical sequences, despite the consistency of the internal standard measurement, could not be explained. Secondly, the population diversity of the sites was explored. Based on the analysis of migratory and dietary behaviors at childhood (from tooth enamel δ 18O and δ 13C, respectively), the following "cultural identities" were suggested: Indigenous, Inuit, French or Anglo-Canadians, North American (as Acadians, Louisianians or Newfoundlanders), prisoners from New England, individual of African descent and European immigrants. The hypothesis of enslavement for some of these individuals was based on the following conditions: origin, death before the age of 17 years and a major shift in diet. This allowed for a deeper comprehension of this aspect of Canadian history. Thirdly and finally, bone carbonate (δ 13Ccarb), and bone collagen (δ 13Ccoll and δ 15N) were used to address the central theme of the thesis, which is the dietary adaptation. Overall, the four sites suggest a retention of European dietary traditions (C3-type diet), a trend similar to what has been perceived at other North American colonial sites located in continental settings (such as Louisiana and Ontario). The French Canadians in Montreal would have consumed more C4 resources (as maize, sugar cane or rum) than the intracontinental migrants (from North America as Acadians or Louisianians). Conversely, the British Isles immigrants consumed more C4 resources that the locally born individuals in Quebec City. Finally, as marine resources were consumed by some individuals in Montreal, an explanation was proposed in relation to Catholic food restrictions.

No / The latest advances in mesocrystal formation and non-classical crystallization of pre-synthesised nanoparticles have been reviewed with the focus on providing a fuller description of a number of complex systems and their properties and applications through examination of the crystallisation mechanisms at work. Two main crystallization principles have been identified; classical crystallization and particle based aggregation modes of non-classical pathways. To understand the non-classical pathways classical crystallization and its basics are introduced before non-classical pathways, such as oriented attachment and mesocrystal formation, are examined. In particular, the various destabilization mechanisms as applied to the pre-synthesized building blocks in order to form mesocrystalline materials as well as the interparticular influences providing the driving forces are analyzed and compared to the mechanisms at work within classical crystallization. Furthermore, the new properties of the mesocrystalline materials that derive from the collective properties of the nanoparticular building units, and their applications potential are presented. It is shown that this new class of materials has the potential to impact in a number of important areas such as sensor applications, energy conversion, photonic crystals as well as for energy storage, optoelectronics and heterogeneous catalysis or photocatalysis.

No / Raman spectroscopy was evaluated as a non-destructive analytical tool for the characterisation of white substances in burials. In addition, Fourier transform Raman spectroscopy was used to assess the conversion of hydrated lime into calcium carbonate. Fourteen samples of white substances from archaeological and forensic sites were analysed and characterised. The results show that not all white residues in burials are lime. Lime can easily be mistaken for other building materials (gypsum), for minerals (brushite) or degraded metal (cerussite). This study highlights the need for chemical analysis of white residues when encountered in burials. Analytical information derived from Raman spectra of white substances can further assist in the interpretation of the taphonomic processes of burials and their funerary context. Copyright (c) 2014 John Wiley & Sons, Ltd.

Le développement de technologies électrosynthétiques pour la production de H2O2 est attrayant du point de vue de la durabilité. L’utilisation de dioxyde de carbone et/ou d’espèces carbonatées comme médiateurs dans l’oxydation de l’eau en peroxyde est apparue comme une voie viable pour y parvenir, mais de nombreuses questions demeurent quant au mécanisme qui doit être abordé avant que des systèmes pratiques n’émergent. À cette fin, ce travail combine des méthodes électrochimiques et spectroscopiques pour étudier les voies de reaction possibles et les facteurs influençant l'efficacité de cette réaction. Nos résultats électrochimiques indiquent que le CO32- est l'espèce clé qui subit une oxydation électrochimique, avant de réagir avec l'eau loin de la surface du catalyseur vers la production de H2O2. Grâce à des expériences spectroélectrochimiques infrarouges et Raman, nous avons noté que l'épuisement du CO32- est un facteur clé qui limite la sélectivité du procédé. À son tour, l'application de l'électrolyse pulsée peut augmenter cela, avec un ensemble initial de paramètres optimisés augmentant la sélectivité de 20 % à 27 %. Dans l’ensemble, ces travaux contribuent à ouvrir la voie au développement futur d’un système électrosynthétique H2O2 pratique. / The development of electrosynthetic technologies for H2O2 production is appealing from a sustainability perspective. The use of carbon dioxide and/or carbonate species as mediators in water oxidation to peroxide has emerged as a viable route to do so but still many questions remain about the mechanism that must be addressed before practical systems emerge. To this end, this work combines electrochemical and spectroscopic methods to investigate possible reaction pathways and factors influencing the efficiency of this reaction. Our electrochemical results indicate that CO32- is the key species that undergoes electrochemical oxidation, prior to reacting with water away from the catalyst surface en route to H2O2 production. Through spectroelectrochemical infrared and Raman experiments, we noted that CO32- depletion is a key factor that limits the selectivity of the process. In turn, showed how the application of pulsed electrolysis can augment this, with an initial set of optimized parameters increasing the selectivity from 20% to 27%. In all, this work helps pave the way for future development of practical H2O2 electrosynthetic system.

The kraft pulping process is the most dominant pulping process consisting of 90% of the chemical virgin pulp production in the world. This process is extensive, especially considering the large chemical recycling, and improvements are constantly ongoing [1]. In 1966, G.H. Tomlinson II published a patent in where a white liquor of 100% sulphidity was used, i.e. only sodium sulphide (Na2S) as a cooking chemical and not sodium hydroxide (NaOH). A higher sulphidity gives an improved delignification and a stronger pulp with a higher yield. In addition, when NaOH is not used in the process, the causticizing plant can be eliminated. According to Tomlinson II, this would mean lower investment and operating costs.  The smelt from the recovery boiler undergoes leaching or evaporating to separate the sodium carbonate (Na2CO3) and Na2S. Na2CO3 recirculates to the black liquor to reduce the sulphur/sodium ratio, which is necessary for the function of the recovery boiler. A sufficiently high proportion of recirculated Na2CO3 is used to ensure that no SO2-emissions occur from the recovery boiler [2]. The purpose of this thesis is to investigate different cases of high sulphidity processes through heat and mass balances and compare it with a reference case of kraft pulp, in order to potentially find a more efficient process. The high sulphidity cases vary with e.g. dry solids content, effective alkali charge and the amount of recirculated Na2CO3. Also, a combination between the conventional kraft pulping process and high sulphidity process will be investigated. Tools for these calculations are given from AFRY and is done in excel. The focus is on the recovery boiler, since it is the most critical aspect in the process, but overall flow charts will also be made.  It turns out that the amount of recirculated Na2CO3 is one of the major factors that determine the outcome of the results. An increased amount of Na2CO3, which contains inert carbon, leads to a lower heating load in the recovery boiler, resulting in too low temperatures. For the high sulphidity process to be feasible, a lower effective alkali charge is required in the digester to reduce the amount of chemicals in the process. This can be achieved through a pre-impregnation step in the digester. All high sulphidity cases also resulted in a decrease in CAPEX and OPEX compared to the reference case. The most interesting result is a combination between the high sulphidity and kraft pulping process, as the results was comparable with the reference case, but at the same time containing advantages of the high sulphidity process. / Kraftmassaprocessen är den dominerade massaframställningen bestående av 90% av världens kemiska jungfrumassa. Denna process är omfattande och förbättringar pågår ständigt, särskilt med tanke på den stora kemikalieåtervinningen [1]. 1966 publicerade G.H. Tomlinson II ett patent där en vitlut av 100% sulfiditet användes, alltså endast natriumsulfid (Na2S) och inte natriumhydroxid (NaOH) som kokkemikalie. En högre sulfiditet ger en förbättrad delignifiering och därmed en starkare massa med ett högre utbyte. När NaOH inte används i kokeriet kan dessutom kaustiseringen elimineras. Det skulle, enligt Tomlinson II, innebära lägre investerings- och driftskostnader.  Smältan som kommer ut från sodapannan genomgår en laknings- eller indunstningsprocess för att separera ut natriumkarbonatet (Na2CO3) och Na2S. Na2CO3 återcirkulerar till svartluten innan sodapannan för att på så sätt minska på svavel till natriumkvoten, vilket är nödvändigt för sodapannans funktion. En tillräckligt hög andel av Na2CO3 återcirkuleras för att inga SO2-emissioner ska förekomma [2]. Syftet med denna rapport är därför att undersöka olika fall av högsulfiditetsprocesser genom värme och massbalanser och jämföra med ett referensfall av kraftmassa, för att i slutändan undersöka en potentiellt mer effektiv process. Fallen varierar med torrhalt på svartluten, effektiv alkali laddning, och mängden återcirkulerad Na2CO3. Ett kombinerat fall mellan den konventionella kraftmassa- och högsulfiditetsprocessen kommer även att undersökas. Verktyg för dessa beräkningsbalanser fås via AFRY och används i Excel. Fokuset ligger på sodapannan då denna del av processen är avgörande för processens genomförbarhet.  Övergripande flödesscheman kommer även att göras för de olika fallen.  Det ska visa sig att mängden återcirkulerad Na2CO3 är en av de större faktorerna till förändringar i resultatet. En ökad mängd Na2CO3, som innehåller inert kol, ger en lägre värmebelastning i sodapannan, och därmed för låga temperaturer i pannan. För att högsulfiditetsprocessen ska kunna vara genomförbar krävs en lägre effektiv alkali laddning i kokeriet för att minska på mängden kemikalier i processen, detta kan göras via ett förimpregneringssteg i kokeriet. Alla högsulfiditetsfall gav även en minskning i CAPEX och OPEX jämfört med referensfallet. Mest intressant resultat gavs av en kombination mellan högsulfiditet och kraftmassaprocess, då den mest efterliknade referensfallet, men samtidigt innehåller fördelar av högsulfiditetsfallet.

Cette thèse porte sur la synthèse de polyuréthanes thermoplastiques plus durables à partir de dérivés des huiles végétales. La première voie étudiée est basée sur la réaction, largement utilisée, entre un diol et un diisocyanate. Aussi, pour s’affranchir de l’utilisation des diisocyanates toxiques, une approche via la polyaddition entre un bis carbonate cyclique et une diamine a également été étudiée. Pour ce faire des précurseurs bi-fonctionnels : diols, bis carbonates cycliques à 5 et 6 chainons et diamines ont été préparés à partir de dérivés de l’huile de tournesol (oléate de méthyle) et de l’huile de ricin (undécénoate de méthyle et acide sébacique). Les propriétés thermo-mécaniques des polyuréthanes et poly(hydroxyuréthane)s thermoplastiques obtenus ont pu être ajustées par le choix adapté de la structure chimique des précurseurs (gras) utilisés. Les travaux réalisés démontrent un effet de la taille du cycle du carbonate sur la réactivité. En effet, les (bis) carbonates cycliques à 6 chainons se sont avérés plus réactifs que leurs homologues à 5 chainons. De plus, la synthèse de diamines via un intermédiaire dinitrile semble très prometteuse pour le « design » d’une plateforme de diamines issues d’acides gras et de poly(hydroxyuréthane)s entièrement bio-sourcés. / This thesis aims to synthesize more sustainable thermoplastic polyurethanes from vegetable oil derivatives. The first route that has been investigated is based on the well-known reaction between a diol and a diisocyanate. Then to avoid the use of diisocyanates, the route via the polyaddition of a bis cyclic carbonate and a diamine have been studied as well. For this purpose, bifunctional precursors such as diols, bis 5- and 6-membered cyclic carbonates and diamines have been prepared from sunflower oil derivative (methyl oleate) and castor oil derivatives (methyl undecenoate and sebacic acid) The thermo-mechanical properties of the PUs have been modulated by designing and selecting the chemical structure of the (fatty acid-based) monomers. The performed model reaction kinetics revealed the higher reactivity of the 6-membered cyclic carbonates compare to the 5-membered ones. Finally, the developed route to fatty acid-based diamines via dinitriles synthesis in mild conditions was really efficient and this route is really promising to develop a fatty acid based-diamines platform and fully bio-based poly(hydroxyurethane)s.