The purpose of the research was to design, build, test, and recommend a process to economically separate CO from a gas mixture of CO, CO2, and O2. The general method considered in this research to accomplish the separation was liquid absorption in a packed column. Several experiments were performed to identify the best process solution to use in a prototype. The experiments, based on the COSORB process, consisted of CuCl mixed with a complexing agent (metal tri-chloride) and a solvent (metal tetra-chloride, toluene, ethanol, etc.). The best method consisted of an aqueous solution of CuCl and MgCl2, which has previously been used for CO absorption experiments reported in the literature. The absorption takes place at elevated pressure (30 psig) and ambient temperature, and the stripping occurs at approximately 75 ºC. Using the apparatus at approximate design conditions, the highest removal of CO was 88% with a product composition of 48%. The highest product composition achieved was 84%; in this case CO removal was 66%. Product composition was low because a significant amount of CO2 physically absorbed into solution (which also decreased the pH of the solution to about 4, according to calculation). The removal of CO should increase with a taller column and higher liquid flow through the column; however, this might decrease the product composition. Advantages of this process are that the raw materials used are relatively cheap, heating and cooling requirements are lower than similar processes, and operation is relatively simple.

Background: Repeated sprint training in hypoxia has shown to be superior to training in normoxia. However, both natural and simulated altitude training are strategies that are not always accessible and expensive due to traveling or the need for advanced equipment. A possible way of simulating hypoxic conditions is to administer carbon monoxide (CO) prior to training as it has been shown to reduce the oxygen transport and delivery to the muscle similar to systemic hypoxia. It is therefore hypothesized that inhaling a small bolus of CO prior to repeated-sprint exercise will potentiate the acute physiological responses during the training, thus induce performance improvements associated with repeated sprint ability compared to placebo control. Methods: 23 endurance-trained individuals (18 men and 5 women), age 33.2 ± 6.9 years, body mass 78.3 ± 11.0 kg, height 180.7 ± 7.3 cm, performed a 3-week supervised repeated sprint exercise protocol on electromagnetically braked cycle ergometers. A repeated sprint ability test was conducted pre-and post-training intervention. Participants were randomly assigned to either inhaling CO (INCO group) or inhaling a sham gas (NOCO group). Analysis of covariance (ANCOVA) was conducted to determine statistical significance by controlling for pre-test values. Results: Periodic inhalation of CO prior to repeated sprint exercise led a medium, significant difference in mean power decrement (INCO -2.63%, NOCO 8%; p <0.05, ηp2 = 0.19) and fatigue index (INCO 0.28%, NOCO 8.2%; p <0.05, ηp2 = 0.24) compared to sham gas, despite that both groups increased in number of sprints (INCO 16.58%, NOCO 27.60%; p <0.05; ηp2 = 0.71) with no difference between groups. Conclusion: Our findings in this study showed a positive effect on an improved ability to sustain power output during repeated sprints when periodic inhalation of CO is administered. Therefore, it is suggested that periodic inhalation of CO prior to repeated sprint exercise might be a nuanced way to induce favorable physiological adaptations, thus improving performance associated with repeated sprint ability.

No description available.

The central aim of this thesis is to give further insights into the structural properties of the calcite(104) surface and especially to unravel its surface reconstruction by clarifying the contradicting reports of the (2 × 1) and row-pairing reconstruction. Within this thesis, the pristine as well as the CO and H2O-covered calcite(104) surface is investigated for the first time with non-contact atomic force microscopy (NC-AFM) operated at 5 K. CO terminated tips are used in the measurements to benefit from the improved contrast capabilities and detailed understanding of contrast formation with these tips.

Concentrations of CO, CO₂, and O₂ in woodstove flue gases are some of the measured inputs required by algorithms used to calculate woodstove efficiency by the stack loss method. Since these algorithms have been shown to be very sensitive to small errors in these input values, it was necessary to determine whether measurements of these compounds are subject to interference. Concentrations of CO, CO₂, and O₂ in a series of flue gas samples were measured using a variety of independent measurement techniques for each compound. The concentrations indicated by each of the measurement techniques for each compound and sample were compared to check for agreement. Disagreement among the measurement techniques for a given compound could indicate interference if some trend could be established. Tests were conducted on four samples taken randomly during each of three stove firings. / M.S.

No description available.

Excessive carbon dioxide (CO₂) emission into the atmosphere is the dominant factor in the global warming effect. The quick development in industries, anthropogenic activities, expansion of electric cars, and AI-Generated Content (AIGC) market significantly increase the energy demand. The emission of CO₂ gas into the atmosphere bounced back to a new high level after the economic recovery across the world following COVID-19. The zero-carbon policies were carried out by more countries to keep the temperature rise within 1.5 ℃ according to the Paris Agreement. However, fossil fuels still occupy the first place in emitting CO₂ into the air, though a lot of renewable appliances have started to run in recent years. Apart from controlling and diminishing the emission of CO2, capture and utilization technologies are the most significant strategy to achieve carbon neutrality before 2050. The utilization of CO₂ has become various, including direct CO2 electrolysis, two-step tandem CO₂ electrolysis, and hybrid process. Some technologies require concentrated CO₂, and the desorption of CO₂ is now becoming an unavoidable and energy-consuming process. In response to the excessive CO₂ emissions into the atmosphere, 2019 is the ninth year in a row that the global mean sea level has risen compared to the year before, setting a new record with a peak of 87.6 mm in the middle of the year. To meet the 1.5 ℃ objective, we should develop novel technologies to capture and convert CO₂ with new heating technology for tandem utilization or skip the specific desorption process to directly produce the value-added chemicals. Carbon materials are widely used in different industrial fields. Since graphene, graphene oxide, and carbon nanotubes have such remarkable properties, these three carbon-based materials have been highly interesting research subjects in recent years. Graphene stands out for its toughness, flexibility, lightness, high resistance, electrical conductivity, and heat conduction. The applications of graphene are very broad: they include electronics to improve the chip performance, flexible screens to enhance the user experience, construction materials to improve safety and save energy, and medical treatment for drug delivery. Thus, the process of producing premium graphene is the remaining problem blocking the development of graphene applications. Graphene is primarily made through two methods: chemical vapor deposition (CVD) and oxidation-reduction (Redox). The substance needed to make graphene using CVD is methane (CH4), and the temperature is around 1000℃, which makes this an energy-intensive method. The oxidation-reduction (Redox) method will need much stronger acids and oxidants to oxidize the graphite and then reduce the graphene oxide to get reduced graphene with defects, which also has a huge demand for energy. The proposed strategy is preparing the graphene by re-carbonization of asphaltene molecules extracted from crude oil or asphalt paving materials. This strategy saves a lot of energy and improves the use rate of abundant asphalt materials. During the synthesis process of graphene, we choose the natural montmorillonite as the substrate material to provide the designed space for re-carbonization reactions. Using this new method and these materials, we can get low-layer (< 3) graphene sheets with remarkable 2D scale. Using a scalable process to generate graphene of superior quality with neglectable defects, the applications of graphene in various fields would be largely enhanced and facilitated. Besides the above applications, graphene has become familiar as a composition of absorbent in the Carbon Capture Utilization and Storage (CCUS) field. To reach the goal of carbon-zero before 2050, the studies of CCUS have prevailed in the past years. The emission of CO2 comes from industry, agriculture, transportation, and other human activities. To overcome the challenge of removing the greenhouse effect, the CO₂ capture technologies are the most important part of the realm of CCUS. CO₂ capture technologies are primarily designed based on the main existing form, such as 3 to 8 % emitted by natural gas power plants, 10 to 18 % coal-fired plants, and 400 ppm (0.04%) in the atmosphere. Hence, a lot of sorbents were designed and produced for various CO₂ sources. Compared with the capture process, the demand for CO₂ desorption is becoming the most energy-intensive process. For example, the amine sorbents can only desorb the CO₂ at a high temperature around 100 to 120 ℃. The alkaline sorbents need protons to generate CO₂. With regard to the heating method, conventional heating, including vapor heating and induction heating, also consumes a lot of energy. To overcome the energy demand challenge, using microwave irradiation to desorb CO₂ becomes a potential solution to reduce the energy demand. Therefore, modified graphene-doped solvent-impregnated polymers (SIPs) were created to capture CO₂ and desorb CO₂ with a faster speed and lower energy consumption. Graphene is extraordinarily responsive to microwave irradiation. Carbon can be quickly heated to >1200℃ using a power of 1000 W at 2.45 GHz within 1 minute. Among the graphene (GN), graphene oxide (GO), and carbon nanotubes (CNTs), the low-layer graphene demonstrates a remarkable ability to absorb the microwave to generate heat to desorb CO₂ and a highly efficient ability to dissipate heat. The synthesized SIPs/GN absorbent can capture 400 ppm, 7%, 15%, and 100% CO₂ with great capacities and desorb the CO₂ with a power of 100 W microwave irradiation within 5 minutes at 50 ℃ for long-term use (50 cycles), accompanying no degradation of amine groups. With a fast and energy-saving heating method, the SIPs/GN sorbents would be one of the longest-lasting materials for industrial applications. In the tandem utilization of CO₂, the high concentration of CO₂ is a foundational reactant for following reactions to value-added products. So, the graphene-doped SIPs give a valuable strategy to lessen the energy demand. Except for the necessity of pure or high concentration of CO₂ for subsequent CO₂ utilizations, the direct conversion of CO₂ is also the other solution to convert the captured CO₂. The dual functional solid materials are one of the current feasible approaches to directly reduce CO₂ by introducing H₂ and catalyst at high temperatures to get CO or CH₄. With the rising trend of electrochemical electrolysis of CO₂, a dual functional liquid absorbent-based electrolyte can be the candidate to directly reduce CO₂. With a relatively slow CO₂ desorption rate compared to 2M MEA and 8 wt.% PEI solutions, the 10 wt.% NOHMs is made to serve as the electrolyte. This is an excellent electrolyte possessing a high conductivity to directly reduce the CO₂ to CO with 0.5 M NaCl and 83.3% less concentration than 2 M MEA + 3 M KCl. Thus, it realizes the same ∼ 20 % Faradaic Efficiency of CO and production rate of CO at 25 ℃. The study of direct reduction of 10 wt.% NOHMs gives inspiration for future large-scale continuous reduction in a flow cell. The high CO2 partial pressure in the reservoir and suitable pH value range would be adopted to convert the CO₂. In addition, the 10 wt.% NOHMs also saves at least 38.63% and 77.71% energy compared to 8 wt.% PEI and 2 M MEA solutions. When the adjusted cathode contact area and the stable current density of CO can give the same product rate of CO with the CO₂ desorption rate, the balance between the desorption rate and conversion rate would be achieved. In sum, the results of this thesis show the combined strategy to capture and convert various CO₂ sources efficiently. Due to the limitation of liquid NOHMs solution to capture and convert the 400 ppm CO₂, the 10 wt.% NOHMs solution is a good approach for 10 to 18 % CO₂ source. The solid SIPs/GN absorbent has a high capacity when capturing 400 ppm CO₂, which is one of the most effective ways for direct air capture (DAC). With the comprehensive capture technologies and excellent conversion rate to CO, the future CCUS technologies will be focused on the combinations of capture, conversion, and storage, with considerations of energy efficiency, process cost and production efficiency.

Dans ce travail nous avons étudié des réactions chimiques sur la surface de deux métaux : le platine et l'or, en utilisant la microscopie ionique à effet de champ électrique (FIM) et la spectrométrie de masse de désorption par champ pulsé (PFDMS). En complément de ces données expérimentales, nous apportons des résultats obtenus par la théorie de la fonctionnelle de la densité (DFT). La taille et la morphologie de nos échantillons font qu’ils sont de bons modèles de grains de phase active dans un catalyseur réel. Sur le platine nous avons observé l'interaction du monoxyde d'azote. En présence d'un champ électrique, la dissociation du NO est promue, laissant sur la pointe une couche d'oxygène que l'on peut titrer par la suite avec du NO pour former du dioxyde d'azote. L'interaction de l'hydrogène avec une pointe de platine est différente en fonction de la température. A basse température (<200 K), l’hydrogène met en image la pointe avec un assombrissement de petites régions de la pointe. A partir de 200 K, l'hydrogène induit une transformation de la pointe : les faces denses s'élargissent au détriment des faces rugueuses, avec une rangée d'atomes le long des lignes de zone [100] et le pôle central passe d’une forme circulaire à une forme carrée. L'hydrogène est supposé être à l'état atomique sur la surface; sous sa forme moléculaire, il ne contribue qu'à la mise en image. C’est sous sa forme atomique qu’il contribue aux transformations observées. La réaction NO+H2 sur le platine conduit à l'observation d'instabilités cinétiques pour des pressions et températures données. Les régions d'amorçage ont été identifiées comme étant tout ensemble de sites de cran situé le long des lignes de zone [100]. L'observation de phénomènes oscillants n'est pas liée exclusivement à une morphologie de type polyédrique : il est possible d’observer ces instabilités cinétiques sur des pointes de rayon de courbure différent, ces pointes ne subissent pas nécessairement un changement de morphologie. L'analyse chimique au cours de la réaction a révélé la présence d'oxydes de surface ce qui nous a conduit à penser que la surface du catalyseur de platine doit être oxydée plutôt que de rester à l'état métallique. Une étape intermédiaire dans le mécanisme de site vacant a été proposée pour permettre de rendre compte de l'apparition de phénomènes oscillants. L’étape déterminante est la décomposition du monoxyde d’azote adsorbé à la surface. L’apport d’hydrogène atomique nécessaire à la formation d’eau n’est pas une étape lente, au contraire l’hydrogène semble être largement présent sous forme atomique. L’influence du champ électrique reste important, ce qui pourrait expliquer les différences de gammes de température auxquelles d’autres groupes et le nôtre observons des oscillations. L'étude de l'interaction du CO seul sur l'or a été motivée par l'observation de la réaction CO+O2 sur pointe d'or. Sous nos conditions expérimentales, il est possible de former des mono- et dicarbonyles d’or sous forme cationique. En présence d'un champ électrique, la formation de carbonyles d'or est promue au niveau des sites de cran de la surface. Les résultats obtenus par DFT sont concordants avec les résultats expérimentaux. A l'instar du Pt, nous avons étudié l'interaction du monoxyde d'azote sur pointe d'or. Nous avons observé la formation de protoxyde d'azote et d'un dimère de monoxyde d'azote. Le mécanisme de formation de ces espèces reste encore inconnu. Une couche d'oxygène adsorbée à la surface peut être titrée par du NO en formant du dioxyde d'azote. En présence d'oxygène seul sur une pointe d'or sans champ électrique, les spectres de masse ne révèlent que la présence d'oxygène moléculaire. En présence d'un champ électrique, il est possible de détecter de l'oxygène atomique sans toutefois avoir la formation d'un oxyde d'or. Il est possible de former de l'ozone à partir d'une pointe recouverte d'oxygène atomique en présence d'oxygène moléculaire gazeux. Les calculs par DFT nous laissent à penser que la formation du cation O3+ ne se fait pas à la surface mais à proximité. Ils montrent entre autres que le champ électrique déstabilise l'oxygène atomique, ce qui pourrait le pousser vers des régions où l'effet du champ est le moins intense (la tige de la pointe).

No description available.

L'assimilation de données permet de combiner d'une manière optimale un modèle numérique décrivant l'évolution de la composition chimique de l'atmosphère et les mesures disponibles. Dans cette thèse, l'assimilation de données est utilisée afin de caractériser les distributions troposphériques et stratosphériques de l'ozone (O3) et du monoxyde de carbone (CO). Le Modèle de Chimie Transport (CTM) MOCAGE (MOdèle de Chimie Atmosphérique à Grande échelle) est utilisé dans une configuration à deux domaines imbriqués avec les résolutions de 2◦ (global) et de 0.2◦ (régional). La technique variationnelle du 3D-FGAT est utilisée pour toutes les études que constituent cette thèse. Nous avons évalué la complémentarité des mesures satellites au limbe et au nadir aujourd'hui disponibles pour la caractérisation de l'UTLS (Haute Troposphère Basse Stratosphère) en assimilant ces deux types de mesures simultanément. Nous nous sommes en particulier intéressé à la propagation de l'information provenant des mesures assimilés dans le modèle et plus particulièrement, aux impacts de l'assimilation de mesures stratosphérique d'ozone en troposphère aux moyennes latitudes. Les principaux objectifs de cette thèse ont été de montrer la valeur ajoutée de l'augmentation de la résolution modèle pour l'assimilation de données et les effets synergiques de l'assimilation combinée d'un sondeur au limbe et au nadir. Des développements au niveau du système d'assimilation en domaine imbriqué à 0.2◦ ont été effectués. L'assimilation des données dans le domaine global est maintenant prise en compte et les conditions aux bords provenant des champs assimilés montre un impact significatif sur le domaine imbriqué. Dans un premier temps, nous avons assimilé les profils d'ozone stratosphériques mesurés au limbe provenant de MLS (Microwave Limb Sounder) afin d'étudier deux cas d'échange entre la Stratosphère et la Troposphère (STE). / Data assimilation combines in an optimal way a numerical model describing the evolution of the atmospheric chemical composition and the available trace gases measurements. In this thesis, data assimilation is used to characterize the ozone (O3) and the carbon monoxide (CO) distributions in the stratosphere and in the troposphere. The Chemistry Transport Model (CTM) MOCAGE (MOdèle de Chimie Atmosphérique à Grande Echelle) is used in a configuration with two nested domains at 2◦ (global) and at 0.2◦ (regional). To perform the assimilation experiments a 3D-FGAT variational method is used. We evaluate the complementarity of limb and nadir measurements available at the present day at characterizing the UTLS (Upper Troposphere Lower Stratosphere) region by assimilating simultaneously the two type of measurements. We particularly focus on the impacts of data assimilation of stratospheric ozone measurements on troposphere and conversely of tropospheric data assimilation on stratosphere. Showing the added value of the increased horizontal resolution in the UTLS assimilated fields and the synergistic effects of limb and nadir assimilation were the main objectives of this work. Development in the assimilation system have been made in the assimilation system with the nested domain. Data assimilation in the global domain is now taken in account and the boundary condition from the assimilated fields show significant impacts on the regional domain. Firstly, we assimilate stratospheric ozone profiles from MLS (Microwave Limb Sounder) to investigate two Stratosphere-Troposphere Exchange (STE) case studies. .