Letteratura scientifica selezionata sul tema "Adsorption et séparation de CO2"
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Articoli di riviste sul tema "Adsorption et séparation de CO2"
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Delprat-Jannaud, Florence. "Le captage et le stockage du CO2". Reflets de la physique, n. 77 (febbraio 2024): 78–85. http://dx.doi.org/10.1051/refdp/202477078.
Testo completoAbstract (sommario):
Le captage et le stockage géologique du gaz carbonique ne sont pas des technologies nouvelles : le captage et la séparation du CO2 sont appliqués dans l’industrie depuis des décennies, et l’injection de CO2 est pratiquée depuis les années 1970 pour la récupération assistée du pétrole. Toutefois, des verrous restent à lever pour leur déploiement à grande échelle. Cet article propose une revue des technologies existantes, qu’elles soient matures ou en cours de développement, ainsi qu’une discussion sur les enjeux à adresser : réduction des couts et de la pénalité énergétique pour le captage du CO2, mutualisation des infrastructures pour le transport, démonstration de la faisabilité du stockage massif ainsi que perspectives en matière d’utilisation.
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Berthod, Alain, Jun Xiang, Serge Alex e Colette Gonnet-Collet. "Chromatographie à contre courant et micelles inverses pour la séparation et l'extraction de cations métalliques". Canadian Journal of Chemistry 74, n. 2 (1 febbraio 1996): 277–86. http://dx.doi.org/10.1139/v96-031.
Testo completoAbstract (sommario):
Countercurrent chromatography (CCC) is a separation technique in which the stationary phase is a liquid. Diethylhexyl phosphoric acid (DEHPA) forms reverse micelles in heptane. Metallic ions, located in an aqueous phase, can be extracted into the aqueous core of the reverse micelles in the heptane phase. A CCC apparatus can be considered as a powerful mixing and extracting machine with efficiency above several hundreds of theoretical plates. La3+, Ce3+, Pr3+, and Nd3+ lanthanide cations were separated using CCC with a DEHPA-containing heptane stationary phase. Studying the retention variations with aqueous mobile phase pH, it was possible to determine the lanthanide extraction constants and separation coefficients. Overloading conditions are described. Frontal chromatography was performed using a Co2+ and Ni2+ solution. The Co2+ ions were concentrated in the heptane + DEHPA stationary phase, a part of the solution was deionized, and another part was enriched in only Ni2+ ions. This method also produced the extraction constants and separation coefficients. The use of CCC with a complexing stationary phase can be applied to any cation for ion filtering and concentration, or for deionization of aqueous phases. Key words: countercurrent chromatography, CCC; ion extraction, ion filtering, deionization, lanthanides, transition metals.
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Jean-Baptiste, Philippe, e René Ducroux. "Potentiel des méthodes de séparation et stockage du CO2 dans la lutte contre l'effet de serre". Comptes Rendus Geoscience 335, n. 6-7 (giugno 2003): 611–25. http://dx.doi.org/10.1016/s1631-0713(03)00086-5.
Testo completo
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Kukulka, Wojciech, Krzysztof Cendrowski, Beata Michalkiewicz e Ewa Mijowska. "Correction: MOF-5 derived carbon as material for CO2 adsorption". RSC Advances 9, n. 59 (2019): 34349. http://dx.doi.org/10.1039/c9ra90077b.
Testo completo
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Jinzhang, Jia, e Xiao Lingyi. "Retraction: Research on CO2/CH4/N2 competitive adsorption characteristics of anthracite coal from Shanxi Sihe coal mine". RSC Advances 14, n. 52 (2024): 38581. https://doi.org/10.1039/d4ra90145b.
Testo completoAbstract (sommario):
Retraction of ‘Research on CO2/CH4/N2 competitive adsorption characteristics of anthracite coal from Shanxi Sihe coal mine’ by Jia Jinzhang et al., RSC Adv., 2024, 14, 3498–3512, https://doi.org/10.1039/D3RA08467A.
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Kottititum, Bundit, Thongchai Srinophakun, Niwat Phongsai e Quoc Tri Phung. "Optimization of a Six-Step Pressure Swing Adsorption Process for Biogas Separation on a Commercial Scale". Applied Sciences 10, n. 14 (8 luglio 2020): 4692. http://dx.doi.org/10.3390/app10144692.
Testo completoAbstract (sommario):
Pressure swing adsorption (PSA) appears to be an effective technology for biogas upgrading under different operating conditions with low greenhouse gas emissions. This study presents the simulation of biomethane adsorption with the adsorption bed filled with a carbon molecular sieve (CMS). A six dual-bed six-step PSA process was studied which produced a high purity of biomethane. The design of the adsorption bed was followed by the real process of which the biomethane capacity was more than 5000 Nm3/h. For the adsorbent, a CMS-3K was used, and a biomethane gas with a minimum 92% purity was produced at 6.5 bar adsorption pressure. To understand the adsorption characteristics of the CH4 and CO2 gases, the Langmuir isotherm model was used to determine the isotherm of a mixed gas containing 55% CH4 and 45% CO2. Furthermore, the experimental data from the work of Cavenati et al. were used to investigate the kinetic parameter and mass transfer coefficient. The mass transfer coefficients of two species were determined to be 0.0008 s−1 and 0.018 s−1 at 306 K for CH4 and CO2, respectively. The PSA process was then simulated with a cyclic steady state until the relative tolerance was 0.0005, which was then used to predict the CH4 and CO2 mole fraction along the adsorption bed length at a steady state. Moreover, the optimal conditions were analyzed using Aspen Adsorption to simulate various key operating parameters, such as flowrate, adsorption pressure and adsorption time. The results show a good agreement between the simulated results and the real operating data obtained from the company REBiofuel. Finally, the sensitivity analysis for the major parameters was presented. The optimal conditions were found to be an adsorption pressure of 6 bar, an adsorption time of 250 s and a purity of up to 97.92% with a flowrate reducing to 2000 Nm3/h. This study can serve as a commercial approach to reduce operating costs.
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Lin, Wenjuan, Guo-Qing Tang e Anthony R. Kovscek. "Sorption-Induced Permeability Change of Coal During Gas-Injection Processes". SPE Reservoir Evaluation & Engineering 11, n. 04 (1 agosto 2008): 792–802. http://dx.doi.org/10.2118/109855-pa.
Testo completoAbstract (sommario):
Summary Our study has two features. First, laboratory experiments measured the change of the permeability of coal samples as a function of pore pressure and injected-gas composition at constant effective stress. Second, adsorption-solution theory described adsorption equilibria and aided interpretation. The gases tested include pure methane (CH4), nitrogen (N2), and carbon dioxide (CO2), as well as binary mixtures of N2 and CO2 of different compositions. The coal pack was initially dry and free of gas, then saturated by each test gas at a series of increasing pore pressures at a constant effective stress until steady state was reached. Thus, the amount of adsorption varied, while the effective stress was held constant. Results show that, (i) permeability decreases with an increase of pore pressure at fixed injection-gas composition, and, (ii) permeability change is a function of the injected-gas composition. As the concentration of CO2 in the injection gas increases, the permeability of the coal decreases. Pure CO2 leads to the greatest permeability reduction among all the test gases. However, 10 to 20% by mole of N2 helps to preserve permeability significantly. According to the mixed-gas adsorption isotherms, adsorption and the selectivity of a particular gas species on coal surfaces is a function of pressure and the gas composition. Therefore, we conclude that loading coal surfaces with adsorbed gas at constant effective stress causes permeability reduction. Finally, gas adsorption and permeability of coal are correlated, simply to extend the usefulness of study results. Introduction Coalbed methane (CBM) has grown to supply approximately 10% of US natural-gas production and is becoming important worldwide as an energy source (EIA 2006). Conventional CBM-recovery procedures stimulate wells and produce CH4 by depressurizing the coalbed. A full understanding of the mechanisms underlying CBM production has yet to be established. Injection of CO2, N2, or mixtures of the two gases enhances CBM recovery significantly (Stevens et al. 1998; Stevens 2001). Coalbeds also present a potential sink for greenhouse gases (GHGs), such as CO2. One issue of particular interest for CO2 injection, and the subject of our study, is the sensitivity of coal permeability to the partial pressure of CO2 in the injection gas.
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Nguyen, Thi Hong Trang, Oriol Gutiérrez Sanchez, Vana Chinnappa Chinnabathini, Dimitra Papamichail, Deepak Pant, Didier Grandjean e Trang Nguyen. "Gas-Phase Pd Clusters-Modified Mesoporous Copper Oxide Hollow Spheres As Electrocatalysts for CO2 Reduction to Ethylene". ECS Meeting Abstracts MA2023-02, n. 57 (22 dicembre 2023): 2756. http://dx.doi.org/10.1149/ma2023-02572756mtgabs.
Testo completoAbstract (sommario):
Renewable energy-driven electrochemical CO2 conversion to value-added chemicals is a prospective strategy for addressing global carbon emission and energy consumption issues worldwide. Until today, only copper-based electrocatalysts can successfully transform CO2 into C2H4 or other desirable C2+ products, but their stability and product selectivity remain insufficient.1 Oxide-derived Cu mesoporous foam catalysts currently show the best selectivity toward C2+ product formation at particularly low overpotentials due to the availability of specific surface sites for C−C coupling in their structure and to the temporal trapping of gaseous intermediates inside the mesoporous catalyst material during CO2 electrolysis.2 To further improve their stability and product selectivity their surface can be modified with metallic clusters that can promote the adsorption of CO2 and the subsequent formation of intermediates. In particular, Pd clusters provide a favorable surface for the initial adsorption of CO2,3 while inducing a continuous restructuring of the Cu surface that maintains its catalytic properties for CO2 reduction to hydrocarbons.4 Herein, we report a novel highly efficient electrocatalyst for CO2 conversion in C2+ products based on mesoporous oxygen-rich copper hollow spheres prepared by a colloid templating method, whose surface is uniformly modified by the deposition of different loadings of well-defined Pd clusters of ca. 3 nm diameter using the laser ablation cluster beam deposition (CBD) technology.5 Primary electrochemical results show that these electrodes are able to reduce CO2 to ethylene with a faradaic efficiency of more than three times higher than that of commercial Cu2O nanoparticles under the same reaction conditions. A clear phase transition from CuO to Cu2O and metallic Cu is occurring under CO2 electro-reduction conditions as highlighted by XRD. These remarkable performances are likely originating from the facile gas charge transport via the mesoporous structure of the oxygen-rich copper spheres as imaged by SEM (Figure 1) as well as from their high surface area, which allows a high catalytic activity and a uniform accommodation of the metallic clusters. As CBD is a versatile technique that allows the deposition of virtually any type of well-defined cluster on a large variety of support, this work provides an attractive avenue to achieve stable selective multicarbon products via rational electrode design. References Kuhl KP, et al., Energy and Environmental Science, 2012;5 (5):7050-7059. Abhijit Dutta, et al., ACS Catal. 2016, 6, 3804−3814 Sichao Ma, et al., J. Am. Soc. 2017, 139, 47−50 Zhe Weng, et al., Angew. Int. Ed. 2017, 56, 13135 –13139 Chinnabathini V. C., et al., Nanoscale, 2023, DOI: 10.1039/D2NR07287D. Figure 1
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Nieszporek, Krzysztof. "Application of the Integral Equation Approach to the Study of Enthalpic Effects Accompanying Mixed-Gas Adsorption on Heterogeneous Solid Surfaces". Adsorption Science & Technology 20, n. 3 (aprile 2002): 243–60. http://dx.doi.org/10.1260/026361702760254432.
Testo completoAbstract (sommario):
The possibilities of the Integral Equation approach for describing mixed-gas adsorption equilibria are presented. In this study, the energetic heterogeneity was described through the use of the Gaussian-like adsorption energy distribution function. As a result, very simple equations describing the isosteric heats of mixture components were obtained. The advantage of the model presented is the possibility of predicting the phase diagrams and enthalpic effects accompanying mixed-gas adsorption from a theoretical viewpoint based on pure-component adsorption data. New equations for isosteric heats of component mixtures were examined using the experimental data obtained by Dunne et al. (1996a, b, 1997), i.e. C2H6, CH4 adsorbed on silicalite and CO2, C2H6 adsorbed on NaX zeolite. The calculations are relatively simple and can be applied industrially.
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Hefti, Max, Lisa Joss, Zoran Bjelobrk e Marco Mazzotti. "On the potential of phase-change adsorbents for CO2 capture by temperature swing adsorption". Faraday Discussions 192 (2016): 153–79. http://dx.doi.org/10.1039/c6fd00040a.
Testo completoAbstract (sommario):
We investigate the potential of a class of recently discovered metal–organic-framework materials for their use in temperature swing adsorption (TSA) processes for CO2 capture; the particularity of the considered materials is their reversible and temperature dependent step-shaped CO2 adsorption isotherm. Specifically, we present a comprehensive modeling study, where the performance of five different materials with step-shaped isotherms [McDonald et al., Nature, 2015, 519, 303] in a four step TSA cycle is assessed. The specific energy requirement of the TSA process operated with these materials is lower than for a commercial 13X zeolite, and a smaller temperature swing is required to reach similar levels of CO2 purity and recovery. The effect of a step in the adsorption isotherm is illustrated and discussed, and design criteria that lead to an optimal and robust operation of the considered TSA cycle are identified. The presented criteria could guide material scientists in designing novel materials whose step position is tailored to specific CO2 separation tasks.
Tesi sul tema "Adsorption et séparation de CO2"
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Venet, Saphir. "Stockage du CO2 et séparation CO2/CH4 par des matériaux de silice à porosité et fonctionnalité contrôlées : étude expérimentale et modélisation de dynamique moléculaire". Thesis, Pau, 2018. http://www.theses.fr/2018PAUU3027/document.
Testo completoAbstract (sommario):
Ce travail vise à évaluer les performances de matériaux à base de silice et à rationaliser leur synthèse en fonction des propriétés d’adsorption recherchées (capacité et/ou sélectivité) en combinant des approches expérimentales et la modélisation de dynamique moléculaire. Ces matériaux devaient idéalement présenter une capacité d’adsorption CO2 mais également une sélectivité CO2 /CH4 élevées. Les différentes étapes de ce travail ont été :- la synthèse et la fonctionnalisation des matériaux de silice,- leur caractérisation texturale et chimique,- la détermination des capacités d’adsorption du CO2, de leur sélectivité CO2/CH 4 ,- les caractérisations par différentes techniques spectroscopiques et microscopiques des échantillons pour essayer de localiser l’adsorption du CO2 et mesurer sa mobilité,- l’identification microscopique par modélisation moléculaire des facteurs physico-chimiques influant sur l’adsorption préférentielle du CO2 et sa diffusivité dans le matériau hôte ainsi que sur le rôle du caractère hydrophile/hydrophobe du matériau de silice par le biais de sa fonctionnalisation.Ces objectifs ont nécessité la préparation de matériaux à surfaces spécifiques élevées par le biais d’un procédé sol-gel simple. Ces matériaux ont été modifiés afin d’obtenir un taux de fonctionnalisation par des groupements -CH3 suffisant pour modifier le caractère hydrophile du matériaux tout en conservant une surface spécifique suffisante. L’influence de la taille des pores a également été sondée.Les capacités d’adsorption des gaz sous pression ont été réalisées pour les gaz purs mais également sur des mélanges CO2/CH4 dans différentes proportions. La sélectivité CH 4 /CO 2 , souvent estimée à partir des isothermes des corps purs et/ou la méthode IAST, a dans ce cas été déterminée à partir de la mesure directe des isothermes des mélanges de gaz. Il est apparu que l’eau joue un rôle crucial sur les capacité et sélectivités d’adsorption. Ce paramètre est l’un de ceux qui a été étudié à travers les simulations de dynamiques moléculaires. L’influence de l’introduction de groupements hydrophobes a également été exploré.Les résultats obtenus par dynamique moléculaire sont dans l’ensemble en bon accord avec les données expérimentales. Ces deux approches parallèles expérience/théorie ont mis en évidence la sélectivité de l’un des matériaux pour des applications où l’effluent gazeux est peu chargé en CO 2This work aims to evaluate the performance of silica-based materials and to rationalize their synthesis according to their desired adsorption properties (capacity and/or selectivity) by combining experimental approaches and the management of the molecular animal. These materials are ideally suited for CO2 adsorption capacity but also CO2/ CH4 selectivity. The different stages of this work were:- the synthesis and functionalization of the silica materials,- their textural and chemical characterization,- the determination of CO2 adsorption capacities, of their CO2/ CH4 selectivity.- the characterizations by various spectroscopic and microscopic techniques of tests to try to locate the adsorption of CO2 and to measure its mobility,- microscopic identification by the factor of physic-Factors influence the preferential adsorption of CO2 and its diffusivity in the role of hydrophilic / hydrophobic character in silica by functional.These objectives required the preparation of high specific surface materials through a simple sol-gel process. These materials have been modified in order to obtain a degree of functionalization with -CH3 groups sufficient to modify the hydrophilic nature of the material while maintaining a sufficient specific surface area. The influence of pore size was also probed.The adsorption capacities of the gases under pressure were carried out for pure gases but also on CO2/ CH4 mixtures in different proportions. The CH4/ CO2 selectivity, often estimated from the pure body isotherms and / or the IAST method, was in this case determined from the direct measurement of the isotherms of the gas mixtures. It has become apparent that water plays a crucial role in adsorption capacity and selectivity. This parameter is one of those studied through molecular dynamics simulations. The influence of the introduction of hydrophobic groups has also been explored.The results obtained by molecular dynamics are on the whole in good agreement with the experimental data. These two parallel experience / theory approaches have highlighted the selectivity of one of the materials for applications where the gaseous effluent is little loaded with CO2
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Orsikowsky, Sánchez Alejandro. "Propriétés d'adsorption de différents substrats microporeux à la séparation de gaz modélisation, caractérisation et méthodologie de sélection". Thesis, Pau, 2019. http://www.theses.fr/2019PAUU3037.
Testo completoAbstract (sommario):
L'objectif de cette thèse est de caractériser et modéliser l'adsorption de gaz (dioxyde de carbone, méthane et azote) sur un adsorbant donné et d’extrapoler les résultats obtenus au comportement macroscopique d'un mélange gazeux dans un procédé d’adsorption industriel afin de mieux comprendre les phénomènes liant la structure des adsorbants à la performance du procédé. Puisque le développement de la méthodologie nécessite la description des mécanismes d’adsorption, il a été décidé de démarrer l’étude avec la famille d’adsorbants la mieux connue et la plus répandue dans l’industrie du fait de son bas coût, sa nature microporeuse et sa stabilité chimique et thermique : les zéolithes.A partir de la revue bibliographique, cinq zéolithes avec des propriétés structurales (cations contenus dans leur structure, morphologie des pores, taille des pores et ratio Si/Al) différentes ont été sélectionnées sous deux morphologies (poudre et billes) pour l’obtention des informations indispensables à la détermination des paramètres clés des modèles d’adsorption. Dans un premier temps, les analyses par porosimétrie gaz avec l’argon à 87 K comme molécule sonde ont permis d’accéder aux propriétés structurales des différents adsorbants (volume poreux, distribution en tailles de pore et surface BET). Une méthode basée sur des analyses couplées de porosimétrie gaz avec du CO2 à 273 K et avec l’argon à 87 K a été proposée pour l’évaluation de l’impact de la mise en forme de l’adsorbant sur l’adsorption du CO2. Dans un deuxième temps, l’adsorption des composés purs a été mesurée sur un intervalle très large de pressions (de 10-5 à 80 bar) et de températures (de 253 K à 363 K) par combinaison de la manométrie à basse pression et haute résolution et de la gravimétrie à haute pression. Ces mesures couplées à celle de la chaleur différentielle d’adsorption et à celle de l’équilibre d’adsorption des mélanges ainsi qu’à des études microscopiques disponibles dans la littérature, ont permis d’identifier et d’analyser les différents mécanismes d’adsorption des gaz considérés. Dès lors, les modèles macroscopiques d’adsorption les plus largement utilisés dans la modélisation et la simulation des procédés de séparation de gaz par adsorption comme ceux de Toth, Sips et bi-Langmuir ont été analysés sur l’ensemble des données expérimentales et des mécanismes d’adsorption identifiés. Ces modèles n’étant pas représentatifs des phénomènes physico-chimiques mis en jeu, ils ne permettent pas une représentation cohérente de plusieurs isothermes et des chaleurs d’adsorption mises en jeu. Ainsi, une nouvelle méthodologie de modélisation de l’adsorption des gaz purs et des mélanges, basée sur des modèles représentatifs des mécanismes d’adsorption a été proposée. Cette nouvelle méthodologie permet de prédire l’adsorption de mélanges de gaz à partir de deux isothermes d’adsorption mesurées pour les gaz purs dans les limites de la gamme de température d’intérêt.Enfin, la dernière partie de l’étude se focalise sur l’intégration des modèles dans un logiciel de simulation des procédés dynamiques d’adsorption et sur leur validation avec des essais de courbes de percée. A cette fin, une nouvelle colonne d’adsorption a été conçue et intégrée dans un pilote existant. Ces tests dynamiques d’adsorption se focalisent sur la séparation CO2/N2 et ont été réalisés sur deux échantillons de billes de zéolithes. L’exothermie de l’adsorption du CO2 étant très significative, le paramètre de transfert thermique entre le gaz et la paroi de la colonne a été identifié comme le paramètre limitant de la Zone de Transfert de Masse (MTZ). Ce paramètre de transfert thermique optimisé a été confronté à différentes corrélations afin de pouvoir le prédire. Ainsi, de façon générale, le modèle dynamique reproduit de manière très satisfaisante les résultats expérimentauxThe aim of this PhD (Cifre) is to describe and model the adsorption of several gases (carbon dioxide, methane and nitrogen) on a given adsorbent and to extrapolate the results to the macroscopic behavior of their mixture in an adsorption industrial process in order to better understand the phenomena linking the adsorbent structure with the adsorption industrial processes performance. Since the study requires the description of the adsorption mechanisms, it was decided to start with the best known and most widespread family of adsorbents in the industry because of its low cost, its microporous nature and its chemical and thermal stability: the zeolites.From the bibliographic review, five zeolites with different structural properties (cations contained inside their structure, pore morphology, pore size and Si / Al ratio) were selected under two shapes (powder and beads) to obtain the essential information for determining the key parameters of the adsorption models. In a first step, gas porosimetry with argon at 87 K as the probe molecule, enabled to get access to the structural properties of the different adsorbents (pore volume, pore size distribution and BET surface). A method based on the coupling of gas porosimetry with CO2 at 273 K and argon at 87 K has been proposed for assessing the impact of adsorbent shaping on CO2 adsorption.In a second step, the adsorption equilibria of pure compounds were measured over a very wide range of pressures (from 10-5 to 80 bar) and temperatures (from 253 K to 363 K) by combining high resolution low pressure manometry and high pressure gravimetry. These experimental methods coupled with the measurement of the differential heat of adsorption and the mixture adsorption equilibria as well as with some microscopic studies available in the literature, enabled to identify and to analyze the various adsorption mechanisms. Then, the performance of the macroscopic adsorption models the most widely used in the simulation of adsorption-based gas separation processes - such as those of Toth, Sips and bi-Langmuir - were analyzed over all the experimental data and the identified adsorption mechanisms. Since these models are not representative of the observed physicochemical phenomena, a new methodology for the modeling of pure gases and mixtures adsorption based on representative models of adsorption mechanisms is proposed. This new methodology makes the prediction of gas mixture adsorption possible from only two pure gas adsorption isotherms measured at the extremes of the temperature range of interest.Finally, the last part of the study focuses on the integration of the proposed models in a dynamic adsorption processes simulation software and on their validation with breakthrough curves tests. To this end, a new adsorption column has been designed and integrated into an existing pilot. These dynamic adsorption tests focus on CO2 / N2 separation only and were carried out on two beads of zeolites. Since the exothermicity of CO2 adsorption is very significant, the thermal transfer parameter between the gas and the column wall has been identified as the limiting parameter of the Mass Transfer Zone (MTZ). The optimized heat transfer parameter has been confronted with different correlations in order to predict it. Thus, the dynamic model reproduces very satisfactorily the experimental results
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Garcia, Edder. "CO2 adsorption from synthesis gas mixtures : understanding selectivity and capacity of new adsorbents". Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10195.
Testo completoAbstract (sommario):
Le développement de nouveaux adsorbants écologiques et efficaces pour la séparation du CO2 nécessite un lien quantitatif entre les propriétés des adsorbants et ses propriétés d'adsorption. Dans ce travail, nous développons une méthodologie qui prend en compte explicitement les propriétés des adsorbants, tels que le diamètre de pore, la densité, la forme de pore et la composition chimique. L'objectif est d'établir des corrélations quantitatives entre les paramètres mentionnés ci-dessus et les forces qui gouvernent la physisorption dans les milieux poreux, c'est à dire les interactions van der Waals et les interactions électrostatiques. Ainsi, les propriétés optimales des adsorbants pour la séparation du CO2 sont identifiées. En parallèle à ces études théoriques, une série d'adsorbants potentiellement intéressants pour la séparation du CO2 par PSA ont été testées expérimentalement. Une étude systématique de l'influence du centre métallique sur les séparations de mélanges CO2/CH4 et CO2/CH4/CO a été réalisée sur MOFs présentant sites coordinativement insaturés. Dans le cas des zéolithes, l'effet de la composition chimie (rapport Si / Al) sur les propriétés de séparation a été étudiés. Les capacités cycliques et des sélectivités ont été déterminées par des expériences de perçage. Les matériaux présentant un bon compromis entre la sélectivité et la capacité de travailler dans les conditions typiques de PSA ont été identifiés. Finalement, une comparaison entre la prédiction du modèle d'adsorption et les expériences a été faiteThe design of new environmentally friendly and efficient adsorbents for CO2 separation requires a quantitative link between the adsorbent properties and adsorption capabilities. In this work we develop a methodology, which explicitly takes into account the adsorbent properties, such as the pore diameter, density, pore shape and chemical composition. The objective is to establish quantitative correlations between the above-mentioned parameters and the forces that govern physisorption in porous media, i.e. van der Waals forces and electrostatic interactions. Thus, the optimal properties of the adsorbent for CO2 separation are identified. In parallel to these theoretical studies, a series of potentially interesting adsorbents for CO2 separation by PSA were tested experimentally. A systematic study of the influence of the metal center on the separations of CO2/CH4 and CO2/CH4/CO mixtures was carried out on MOFs presenting coordinatively unsaturated sites. In the case of zeolites, the effect of the framework composition (Si/Al ratio) on the separation properties was studied. The cyclic capacities and selectivities were determined by breakthrough experiments. Materials presenting a good compromise between selectivity and working capacity under typical PSA conditions were identified. Finally, a comparison between the prediction of the adsorption model and the breakthrough experiments is carried out
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Madariaga, Calles Luis Fernando. "Particules imprégnées : mise en œuvre et application aux procédés de séparation de mélanges gazeux en lit fixe". Thesis, Vandoeuvre-les-Nancy, INPL, 2009. http://www.theses.fr/2009INPL036N/document.
Testo completoAbstract (sommario):
Ce travail de thèse repose sur l'étude d’un objet original : des particules solides poreuses imprégnées de liquide non volatil. L'objectif principal de cette thèse est de démontrer le potentiel d’un tel système pour des applications innovantes dans le domaine du traitement de gaz en lit fixe en particulier. Le premier axe de recherche de notre travail concerne l’étude détaillée des processus d’imprégnation de particules de silice par un liquide. Une partie importante du travail est dédiée à la caractérisation des particules imprégnées par une méthode innovante basée sur la rhéologie des poudres très sensible aux changements de surface qui permet de décrire de façon précise l’état d’une particule imprégnée et de comprendre la dynamique du processus d'imprégnation. Une évolution en trois étapes est proposée : adsorption du polymère, infiltration dans les pores et enrobage de la particule. Une seconde partie concerne une étude des propriétés thermodynamiques de plusieurs systèmes liquide – gaz pour identifier le type d’application et le type de composés pour lesquels ce système pourrait s'avérer intéressant. Le système N2-CO2 avec une amine polymère a été choisi pour l’étude expérimentale. Dans la dernière partie, un modèle du procédé est présenté pour simuler les performances de nos particules imprégnées en lit fixe. Ce modèle est validé avec nos résultats expérimentaux. L'objectif de ces simulations est d'identifier les conditions opératoires optimales des différents cycles d'absorption-désorption pour lesquelles les pourcentages de récupération et de concentration du CO2, pour notre application expérimentale, sont maximauxThis work is about an original object: porous particles impregnated with a non volatile liquid. The aim of this work is to show the potential of such a system for applications in the area of gas treatment on fixed beds. The first part of our work is dedicated to the impregnation process and the characterization of such particles by an innovative technique based on powder rheology. This technique is very sensitive to changes on the surface of the particles and helps to understand the impregnation process. Three stages of impregnation are proposed: adsorption of the polymer, filling of the pores and coating of the outer surface. The second part is focused on a thermodynamic study of the properties of some gas-absorbent systems in order to identify the systems for which the retention capacity would be important. The absorbents are compared to activated carbon. A system N2-CO2 with a polymer amine was selected to impregnate the particles and carry out the experimental tests. A model of the process is presented in order to simulate and anticipate the performance of the particles for different operating conditions. The goal of this simulation is to identify the optimal conditions for the absorption-desorption cycles in which the values of recuperation and concentration of CO2 would be maximal
5
Chabanon, Élodie. "Contacteurs à membranes composites et contacteurs microporeux pour procédés gaz-liquide intensifiés de captage du CO2 en post-combustion : expérimentation et modélisation". Paris, ENMP, 2011. http://www.theses.fr/2011ENMP0061.
Testo completoAbstract (sommario):
La réduction des émissions de CO2 anthropique est un des enjeux majeurs du 21eme siècle pour de nombreux pays. De nombreux procédés sont développés pour le captage du CO2, parmi lesquels l'absorption gaz-liquide par contacteur membranaire. L'utilisation d'une membrane permet d'intensifier le transfert grâce à une aire interfaciale développée 2 à 10 fois plus élevée (1000 à 5000 m2. M-3) que celle d'une colonne d'absorption (procédé de référence). Deux types de fibres sont étudiées : microporeuses et composites. Dans une partie expérimentale, l'influence de la nature des matériaux, des paramètres géométriques et opératoires sur les propriétés de transfert de matière et sur la stabilité des performances de captage des contacteurs membranaires est étudiée. Les résultats obtenus pour des durées d'expérimentation courte (dizaine d'heures de temps de contact), sont en adéquation avec les résultats présents dans la littérature. Bien que l'ajout d'une peau dense à un support poreux constitue une résistance supplémentaire au transfert de matière, une étude dédiée, effectuée sur des temps de contact importants (plusieurs centaines d'heures), a permis pour la première fois de valider le concept de résistance au mouillage des fibres à peau dense, comparativement aux fibres microporeuses (PP et PTFE). Dans une partie modélisation, une étude comparative d'approches mathématiques de complexité croissante a été menée. Un seul paramètre ajustable a été délibérément retenu : le coefficient de transfert de matière dans la membrane (km). Cette étude a estimé des valeurs de km obtenues par ajustement des données expérimentales dans la plage de données rapportées dans la littérature (10-2 à 10-5 m. S-1). Cependant, l'hypothèse d'une valeur caractéristique du km qui dépend du régime de fonctionnement est posée et commentée. Cette approche diffère singulièrement des travaux rapportés dans la littérature, qui postulent le plus souvent une valeur unique pour un matériau membranaire donné. Dans ces conditions, l'intérêt des fibres composites, qui présentent une valeur constante et vraisemblablement prédictible du coefficient de transfert membranaire de par leur résistance aux phénomènes de mouillage, apparaît comme particulièrement prometteur pour intensifier les procédés de captage du CO2 en post-combustion par absorption gaz-liquideThe decrease of the CO2 anthropogenic emissions is one of the main aims of the 21st century. Different processes are developed in order to capture CO2, but gas-liquid absorption in packed columns is considered as the reference postcombustion technology. Membrane contactors, which could potentially decrease by a factor 2 to 10 the size of the absorption units due to an increased interfacial area (1000 to 5000 m2. M-3 ), a so-called intensification effect, have been investigated in this study. Two kind of hollow fibers are studied: microporous and composite membranes (i. E. A dense polymeric skin coated on a porous support). In a first part, a series of experiments is reported to evaluate the influence of some geometric and operating parameters on the process capture performances and on the mass transfer characteristics. Results obtained on short time scale experiments are in agreement to the literature results. Even though a dense skin layer on a porous support generates an additional resistance to the mass transfer, a dedicated study carried out on long time scale (several hundreds hours) show for the first time that mass transfer performances of composite fibers can be similar to microporous unwetted membranes. Moreover, the wetting resistance of the composite fibers compared to microporous hollow fibers (PP and PTFE) is clearly demonstrated. In a second part, a comparative study of different mathematical models with increasing complexity is carried out. One parameter is used to fit the experimental results: the membrane mass transfer coefficient (km). Km values obtained through curve fits are in the range of data reported in the literature (10-2 to 10-5 m. S-1). However, the assumption of a km effective value which would depend of the operating conditions is addressed and discussed. This approach is different from the studies reported in the literature which generally postulates a single value for a given membrane material. Under these conditions, the composite membrane interest, which shows a constant and probably predictable value of the membrane mass transfer coefficient due to their wetting resistance, seems to be promising to intensify the gas-liquid absorption process in CO2 postcombustion capture
6
Le, Guillouzer Clement. "Etude spectroscopique de membranes à matrice mixte polymère/MOF pour la séparation CO2/N2". Thesis, Normandie, 2017. http://www.theses.fr/2017NORMC242/document.
Testo completoAbstract (sommario):
Dans le cadre de la réduction des émissions de gaz à effet de serre, une des approches possibles consiste en l’utilisation de membranes pour séparer le CO2 de mélanges gazeux. Durant ce travail de thèse, la séparation CO2 / N2 dans des conditions de post-combustion a été étudiée pour des membranes à matrice mixte composées de matériaux organométalliques poreux, les MOF, insérés dans des polymères. Plus spécifiquement, la thèse porte sur la caractérisation de ces membranes à l’aide des spectroscopies vibrationnelles (IR et Raman). Différentes membranes polymériques et membranes à matrice mixte basées sur des polymères commerciaux comme le Matrimid ou le PEBAX ou des nouveaux polymères comme le PIM-1 ou 6FDA-DAM plus performants ont ainsi été étudiées. La spectroscopie Raman a d’abord été utilisée pour contrôler l’homogénéité des membranes et la bonne dispersion du MOF au sein du polymère à l’aide du Raman. Les interactions entre le polymère et le MOF ont également été étudiées à l’aide des spectroscopies IR in situ et Raman, notamment pour des composites modèles permettant de maximiser les interactions entre les deux composés. La deuxième partie du travail a été axée sur la caractérisation spectroscopique (IR operando) de ces membranes dans les conditions de post-combustion, simultanément à la mesure de leurs performances en séparation. Un système de mesures dédié a donc été spécialement développé. Cette méthodologie permet de comparer directement les données d’adsorption et de séparation des membranes. En développant une nouvelle approche couplant les aspects cinétiques et thermodynamiques de l’adsorption et de la perméation, les données expérimentales ont été modélisées afin de déterminer les paramètres d’adsorption et de diffusion des différentes membranesIn the frame of the abatement of greenhouse gases, one of the possible approaches concern the use of membranes to separate CO2 from gas mixtures. During this PhD work, CO2 / N2 separation in post-combustion conditions has been studied for Mixed Matrix Membranes constituted by porous organometallic materials, MOFs, inserted into polymers. More specifically, this work aims at the characterization of these membranes using vibrational spectroscopies (IR and Raman). Different membranes, purely polymeric or Mixed Matrix Membranes, based on commercial polymers such as Matrimid or PEBAX as well as new polymers such as PIM-1 or 6FDA-DAM have been studied. Raman spectroscopy was first used to control the homogeneity of the membranes and the good dispersion of the MOF within the polymer. The interactions between the polymer and the MOF were also studied using IR in situ and Raman spectroscopies, notably for composites allowing maximizing the interactions between the two components. The second part of the work focused on the characterization of these membranes under operating post-combustion conditions, simultaneously with the measurement of their separation performance. For this purpose, a specifically designed measurement system has been developed in order to be able to test the membranes using IR operando. This methodology allows the direct comparison of adsorption and separation data. By the development of a new approach coupling kinetic and thermodynamic aspects of adsorption and permeation, experimental data were modelled to determine adsorption and diffusion parameters of the various membranes
7
Magisson, Aymeric. "Synthèse de nanοzeοlithes à petits pοres sélectifs". Electronic Thesis or Diss., Normandie, 2024. http://www.theses.fr/2024NORMC253.
Testo completoAbstract (sommario):
L'objectif principal de cette thèse de doctorat est le développement de zéolithes à petits poresde taille nanométriques, ciblant une sélectivité d'adsorption élevée pour le CO2. Les deuxpremiers chapitres présentent l'état de l'art actuel sur diverses caractéristiques et propriétés deszéolithes, leurs voies de synthèse et applications. Les procédures de synthèse réalisées dans cetravail de thèse et les techniques de caractérisation utilisées sont également présentées. Letroisième chapitre décrit le comportement d'adsorption du CO2 à faible pression partielle dansle réseau poreux de la chabazite nanométrique (CHA) synthétisée en présence de cationscalcium et baryum utilisés comme agents structurants. Le quatrième chapitre détaille lacristallisation des phases pures et échantillons imbriqués de chabazite (CHA)/phillipsite (PHI).Les performances des zéolithes obtenues sont évaluées en adsorption de dioxyde de carbone etd'azote. Enfin, le cinquième chapitre présente le développement d'une procédure de synthèseautonome pour des zéolithes nanométriques, et détaille les étapes suivies afin d’optimiser sesconditions opératoires. Cette synthèse réalisée par un robot se situe à l'interface entre la synthèseà grande échelle et l'expérimentation par criblage, offrant les moyens de reproduire facilementdes synthèses exigeantesThe main objective of this PhD thesis is the development of small-pore nanosized zeolitestargeting a high adsorption selectivity towards CO2. The first two chapters present the currentstate of the art on various features and properties of zeolites, their synthesis routes, andapplications. The syntheses procedures carried out in this work and the characterisationtechniques used are presented. The third chapter describes the low partial pressure adsorptionbehaviour of CO2 in the porous network of nanometric Chabazite (CHA) synthesised in thepresence of calcium and barium cations used as structure-directing agents. The fourth chapterdetails the crystallisation of pure phases and intergrown chabazite (CHA)/Phillipsite (PHI)zeolite samples. The performance of the obtained zeolites is evaluated in adsorption of carbondioxide and nitrogen. Finally, the fifth chapter presents the development of an autonomoussynthesis procedure for nanosized zeolites and details the steps involved in optimising itsoperating conditions. This synthesis carried out by robot stands at the interface between largescalesynthesis and screening experimentation, providing the means to easily reproducechallenging syntheses
8
Boucif, Noureddine. "Modélisation et simulation de contacteurs membranaires pour les procédés d'absorption de gaz acides par solvant chimique". Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0280/document.
Testo completoAbstract (sommario):
L'objectif primordial de cette thèse est la recherche de modèles mathématiques qui sont à mieux de décrire le processus d'absorption gaz-liquide dans un contacteur membranaire à fibres creuses poreuses ou denses. La configuration géométrique de ces contacteurs combinée à leur compacité, et de leur faible consommation d'énergie leur permet de se substituer progressivement aux procédés conventionnels tels les colonnes à garnissage et autres tours d'absorption. Notre but est d'étudier la performance de ces processus novateurs par l'élaboration de modèles mathématiques de plus en plus rigoureux. Pour cela, nous avons étudié plusieurs cas de figures où l'hydrodynamique d'écoulement des fluides, la nature du soluté et/ou du solvant ont été changées. Dans un premier temps, il n'a été tenu compte que de l'hydrodynamique du compartiment côté fibre pour deux types de processus d'absorption avec et sans réaction chimique. Par la suite, l'hydrodynamique d'écoulement des fluides dans le côté fibre comme côté calandre a été prise en considération. Des modèles ont été développés pour l'absorption classique de gaz carbonique dans des solutions de monoéthanolamine (liquide d'absorption de référence) où l'écoulement du fluide côté calandre est assimilé à un écoulement piston dans un premier cas, obéissant au modèle dit de surface libre "modèle de Happel" dans un deuxième cas, et enfin caractérisé par des équations de moments de Navier-Stokes dans un troisième cas. La comparaison des résultats numériques de ces modèles a montré que ceux du troisième cas de figure sont les plus proches des résultats d"essais expérimentauxThe overarching objective of this thesis is the research of mathematical models which are better to describe the process of gas-liquid absorption in a membrane contactor with porous or dense hollow fibers. The geometric configuration of these contactors, combined with their low energy consumption and their compactness, allows them to gradually replace conventional processes such as packing towers and absorption columns. Our goal is to study the performance of these innovative processes by developing more rigorous mathematical models. In this scope, we studied several cases where the hydrodynamics of fluid flow, the nature of the solute or solvent have been changed. First, only the hydrodynamics of the fibre side compartment has been taken into account for two types of an absorption process with and without chemical reaction. Subsequently, the hydrodynamics of fluid flow in both the fiber side as shell side were taken into consideration. Models have been developed for classical carbon dioxide absorption in monoéthanolamine solutions (liquid absorption of reference) where the flow fluid in the shell were is assumed to obey a plug-flow in a first case, described by the surface free model known as "Happel model" in a second case, and finally characterized by the momentum Navier-Stokes equations in a third case. The comparison of the numerically simulated results collected from the three models showed that those of the third case matched very closely with the laboratory experimental results
9
Coupan, Romuald. "Clathrates d’Hydroquinone : aspects fondamentaux et appliqués pour la séparation du CO2 d’un mélange CO2/CH4". Thesis, Pau, 2017. http://www.theses.fr/2017PAUU3033/document.
Testo completoAbstract (sommario):
Les clathrates organiques, particulièrement ceux formés entre l’hydroquinone (HQ) et les gaz, sont des entités supramoléculaires montrant un potentiel intéressant comme matériau alternatif pour les applications de stockage et de séparation de gaz. Cette étude traite de l’évaluation du clathrate d’HQ pour la séparation du CO2 contenu dans les mélanges CO2/CH4 par réaction gaz-solide. D’un point de vue fondamental, différentes propriétés des clathrates d’HQ-CO2, -CO2/CH4 et -CH4 ont été analysées: signatures spectroscopiques, structures cristallines, morphologies, capacités de stockage de gaz, températures de relargage de gaz et températures de transition structurales. Ce travail offre aussi de nouveaux éléments de compréhension des mécanismes de formation et de dissociation des clathrates d’HQ. Il est montré que, pour capturer efficacement et sélectivement le CO2, la réaction d’enclathration doit être faite en utilisant l’intermédiaire « clathrate vide » formé à partir du clathrate d’HQ-CO2. D’un point de vue pratique, les courbes d’équilibre, les enthalpies de dissociation, et les occupations dans les conditions d’équilibre ont été déterminées pour les clathrates d’HQ-CO2 et -CH4 dans une gamme étendue de température allant de 288 à 354 K. De plus, la cinétique de la réaction d’enclathration a été étudiée expérimentalement et modélisée. Dans cette optique, un matériau composite à base d’hydroquinone a été développé, et permet de capter et stocker le gaz de manière réversible, et d’améliorer significativement la cinétique d’enclathration. Le procédé de séparation de gaz basé sur la formation du clathrate d’hydroquinone a aussi été étudié. L’influence des paramètres opératoires (i.e. temps de réaction, pression, température et composition du gaz d’alimentation) sur la cinétique de capture, la sélectivité et la capacité de stockage de gaz ont été évaluées à travers des expériences menées à l’échelle piloteOrganic clathrate compounds, particularly those formed between hydroquinone (HQ) and gases, are supramolecular entities recently highlighted as promising alternatives for applications such as gas storage and separation processes. This study deals with an evaluation of the HQ clathrates to separate CO2 from CO2/CH4 gas mixtures through direct gas-solid reaction. On the fundamental point of view, new insights into several properties of the CO2-, CO2/CH4-, and CH4-HQ clathrates were studied: spectroscopic signatures, crystal structures, morphologies, gas storage capacities, guest release temperatures and structural transition temperatures. This work also offers new elements of understanding HQ clathrate formation and dissociation mechanisms. It is shown that, for capturing CO2 the most selectively and efficiently, the enclathration reaction has to be done with the “guest-free intermediate” derived from the CO2−HQ clathrates. On a practical point of view, the equilibrium curves, the dissociation enthalpies, and the occupancies at the equilibrium clathrate forming conditions, were determined for the CO2- and CH4-HQ clathrates in an extended range of temperature from about 288 to 354 K. Moreover, the kinetics of the gas-solid enclathration reaction were studied experimentally and modelled. In this way, HQ-based composite materials were developed and allows to reversibly capture and store gases, and to significantly improve the enclathration kinetics. The hydroquinone clathrate based gas separation (HCBGS) process was also investigated. The influence of the process operating parameters (i.e. reaction time, pressure, temperature and feed gas composition) on the CO2 capture kinetics, the selectivity toward CO2, and the storage capacity were assessed through experiments performed at pilot scale
10
Peralta, David. "Evaluation des Metal-Organic Frameworks en adsorption et séparation des hydrocarbures". Phd thesis, Université de Haute Alsace - Mulhouse, 2011. http://tel.archives-ouvertes.fr/tel-00730462.
Testo completoAbstract (sommario):
L'objectif de cette thèse était d'évaluer quelques Metal-Organic Frameworks (MOFs), choisis en fonction de leur taille de pores, de leur volume poreux et de leur stabilité thermique, en adsorption et séparation des hydrocarbures. Pour étudier le comportement général des MOFs nous avons choisi des MOFs avec des centres métalliques insaturés, des MOFs à charpente anionique et des ZIFs neutres et avons étudié leur sélectivité en séparation de trois familles d'hydrocarbures, à savoir alcanes, alcènes, aromatiques. Les MOFs à centre métallique insaturé se comportent généralement comme des zéolithes polaires, les ZIFs comme des zéolithes apolaires et/ou comme des tamis moléculaires. Les adsorbants les plus prometteurs sont testés sur des séparations d'intérêt industriel telles que la séparation des isomères de xylène, la séparation des paraffines linéaires, monobranchées et di-branchées et l'adsorption sélective du thiophène en vu de l'évaluation de ces adsorbants en désulfuration des essences.
Capitoli di libri sul tema "Adsorption et séparation de CO2"
1
Johnston, Keith P., e C. T. Lee. "Interfacial Phenomena with Carbon Dioxide Soluble Surfactants". In Green Chemistry Using Liquid and Supercritical Carbon Dioxide. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780195154832.003.0013.
Testo completoAbstract (sommario):
A fundamental understanding of colloid and interface science for surfactant design in CO2-based systems is emerging on the basis of studies of interfacial tension and surfactant adsorption (da Rocha et al., 1999) along with complementary studies of colloid structure (Chillura-Martino et al., 1996; Meredith and Johnston, 1999; Wignall, 1999) and stability (Meredith and Johnston, 1999; O’Neill, 1997; Yates et al., 1997). The interfacial tension, γ, between a supercritical fluid (SCF) phase and a hydrophilic or lipophilic liquid or solid, along with surfactant adsorption, play a key role in a variety of processes including nucleation, coalescense and growth of dispersed phases, formation of microemulsions and emulsions (Johnston et al., 1999), particle and fiber formation, atomization, foaming (Goel and Beckman, 1995), wetting, adhesion, lubrication, and the morphology of blends and composites (Watkins et al., 1999). The first generation of research involving surfactants in SCFs addressed water/oil (w/o) microemulsions (Fulton and Smith, 1988; Johnston et al., 1989) and polymer latexes (Everett and Stageman, 1978) in ethane and propane (Bartscherer et al., 1995; Fulton, 1999; McFann and Johnston, 1999). This work provided a foundation for studies in CO2, which has modestly weaker van der Waals forces (polarizability per volume) than ethane. Consequently, polymers with low cohesive energy densities and thus low surface tensions are the most soluble in CO2: for example, fluoroacrylates (DeSimone et al., 1992), fluorocarbons, fluoroethers (Singley et al., 1997), siloxanes, and to a lesser extent propylene oxide. Since CO2 is nonpolar (unlike water) and has weak van der Waals forces (unlike lipophilic phases), it may be considered to be a third type of condensed phase. Surfactants with the above types of “CO2-philic” segments and a “CO2-phobic” segment have been used to form microemulsions (Harrison et al., 1994; Johnston et al., 1996), emulsions (da Rocha et al., 1999; Jacobson et al., 1999a; Lee et al., 1999b), and organic polymer latexes (DeSimone et al., 1994) in CO2. Microemulsion droplets are typically 2–10 nm in diameter, making them optically transparent and thermodynamically stable, whereas kinetically stable emulsion droplets and latexes in the range of 200 nm to 10 mm are opaque and thermodynamically unstable.
Atti di convegni sul tema "Adsorption et séparation de CO2"
1
Liu, Zhiyuan, Haifeng Zhao, Yanqi Sun e Lu Xiao. "Quantitative Analysis of the Effect of CO2 Adsorption on the Permeable Characteristics of Coal Under True Triaxial Stress Conditions". In 57th U.S. Rock Mechanics/Geomechanics Symposium. ARMA, 2023. http://dx.doi.org/10.56952/arma-2023-0022.
Testo completoAbstract (sommario):
ABSTRACT As a heterogeneous porous medium, the anisotropy of the coal body increases the difficulty of retesting and studying the mechanism of internal gas migration. Therefore, in this paper, we analyzed the mechanism of carbon dioxide adsorption properties in the evolution of coal body deformation and permeability. The results of this study are as follows: (1) The adsorption pressure of the coal body was divided into slow increase zone, stable increase zone, and rapid increase zone. (2) With the increasing pressure of the gas, there are two distinct turning points in the changing trend of coal permeability, which is divided into the slow increase zone and the rapid increase zone. (3) the effect of gas adsorption on the permeability of coal consisted of sensitive and insensitive areas. When the gas pressure was less than 1MPa, the impact of gas adsorption on the coal sample permeability was insignificant, while the effect was significant when the gas pressure was in the range of 1-2 MPa. INTRODUCTION Carbon dioxide (CO2) and methane (CH4) are the main components of greenhouse gases, which are mainly derived from the burning of non-coal fuels and exhaust from coal mines, respectively. The rapid increases in these two types of gases will trigger global warming issues. Implementation of CO2 capture and sequestration technology (CO2 capture and sequestration, CCS) can reduce CO2 emissions from the energy industry by 20% (Haszeldine, 2010; Oschatz & Antonietti, 2017). CO2 can be sealed in depleted oil and gas layers, and uneconomical coal seams(Konstantinovskaya et al., 2014; Rutqvist et al., 2008; Yamamoto et al., 2013). In particular, when sealed in coal seams, CBM can be replaced. Therefore, the intensive extraction of coal seam gas (CH4) and the realization of CO2 sequestration technology (CO2 sequestration in coals with enhanced coal-bed methane recovery, CO2-ECBM) have attracted extensive research attention from researchers in China and abroad (Li et al., 2011; P. Liu et al., 2019; Onoja et al., 2019; Raziperchikolaee & Mishra, 2019; Vilarrasa et al., 2010)
2
Fakher, Sherif, Abdulla Hassanin, Sara Tamer, Mohamed Eltohamy, Bassel Abdelaty, Aseel Alsakkaf e Shams Eldakar. "Direct Carbon Dioxide Capture at Atmospheric Conditions via Adsorption Desorption Hysteresis Using Shape-Dependent Prozzolanic Material". In 57th U.S. Rock Mechanics/Geomechanics Symposium. ARMA, 2023. http://dx.doi.org/10.56952/arma-2023-0199.
Testo completoAbstract (sommario):
ABSTRACT One of the main solutions for carbon dioxide (CO2) emissions is carbon capture and storage. Carbon capture technologies, although abundant, are very costly and therefore their application is limited. This research introduces a novel technique for carbon capture that is extremely low in cost and applicable at atmospheric conditions with no pressurization requirements. This method is designed based on the utilization of waste material for sustainability and reduction in environmental impact. The selection of the material was the first step into determining the CO2 storage potential. The material selected was a fly ash produced as a byproduct of clinker manufacturing. The fly ash was then used in three different shapes including powder, cube, and hemi-spherical shape. Following this, the CO2 storage capacity was quantified based on the CO2 adsorption to the material. The shape was one of the most significant findings in this project as changing the shape and size of the fly ash resulted in a significant alteration of the adsorption capacity. The cycles of adsorption and desorption had no significant impact on the fly ash itself which indicated that it does not need to be replaced. This research introduces a small working model for a new design that can assist in carbon capture at ambient conditions. INTRODUCTION The carbon capture, utilization, and storage (CCUS) initiative highlighted to importance of reducing greenhouse gas emissions by capturing the CO2 from different sources, utilizing the captured CO2 in different industries, and the storing the excess CO2 in different forms (Fakher, S. et al., 2020; 2021; 2022). Although CCUS is a widely researched topic, there are still some major challenges associated with this topic especially carbon capture. Although many technologies have been introduced for carbon capture, many of which are in pilot stage, the majority of these methods are extremely costly (Fakher, S., 2020). This is the main limitation that has resulted in the low level of global implementation. It is therefore important to find advancements that can reduce the overall cost of carbon capture in order to globalize the CCUS initiative in the near future.
3
Tian, Jianwei, e Yanan Gao. "A THM Model for CH4-CO2 Transport in Fractured Coal". In International Geomechanics Conference. ARMA, 2024. https://doi.org/10.56952/igs-2024-0655.
Testo completoAbstract (sommario):
ABSTRACT: In the context of the global energy transition and the drive towards achieving net-zero carbon emissions, unconventional gas extraction methods have gained significant attention. This paper presents an advanced fully coupled thermo-hydro-mechanical (THM) model for enhancing methane (CH4) production and simultaneously storing carbon dioxide (CO2) in fractured coal seams. Our innovative approach integrates the complex interactions between thermal, hydraulic, and mechanical processes within the fracture network, addressing the dynamic evolution of matrix and fracture permeability ratios. By injecting CO2 into coal seams, methane is desorbed and produced more efficiently, while CO2 is securely stored within the fractures and pores of the coal matrix. The proposed model investigates the dual benefits of enhanced CH4 production and CO2 storage, offering a sustainable solution for energy production and greenhouse gas mitigation. Comprehensive simulations demonstrate the model's effectiveness in improving gas recovery rates and provide insights into the long-term stability of CO2 storage in geological formations. This study highlights the critical role of THM coupling in fracture networks and the dynamic permeability changes, ensuring a robust and efficient process for both gas extraction and CO2 sequestration, thereby contributing to the goals of the energy transition and net-zero carbon targets. 1. INTRODUCTION The burgeoning energy demands of rapidly developing nations such as China and India have propelled coal seam gas (CSG), primarily methane (CH4), to the forefront as a significant energy resource. Simultaneously, escalating concerns over climate change have underscored the urgency for effective carbon dioxide (CO2) sequestration methods. Injecting CO2 into coal seams emerges as a promising strategy that not only facilitates long-term CO2 storage but also enhances CH4 recovery, offering a dual benefit of energy production and greenhouse gas mitigation (Gunter et al., 1998; Luo et al., 2013). Despite the potential, the application of CO2 enhanced CH4 recovery and the simultaneous decarbonization faces substantial obstacles. Key among these are the complex multiphysics phenomena inherent in the process, including gas adsorption/desorption, diffusion, and the mechanical deformation of coal matrices (Bustin et al., 2016). The multiscale heterogeneity of coal seams—characterized by variations in porosity, permeability, and the presence of natural fractures—further complicates predictive modelling and optimization efforts. These challenges necessitate sophisticated modelling approaches to accurately simulate and manage the gas transport and storage mechanisms within coal seams.
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Xie, Yonggang, XuHao Fan, Changjing Zhou, Haizhu Wang, Zelong Mao, Bin Wang, Fengxiang Mao, Sergey Stanchits e Alexey Cheremisin. "Study on Fracture Initiation and Expansion of Coal Rock by CO2 Foam Fracturing". In 58th U.S. Rock Mechanics/Geomechanics Symposium. ARMA, 2024. http://dx.doi.org/10.56952/arma-2024-1023.
Testo completoAbstract (sommario):
ABSTRACT: To investigate the crack initiation and propagation mechanism of CO2 foam fracturing coal rock. In this study, experiments were conducted on CO2 foam fracturing of coal rock using custom-designed indoor quasi-triaxial and true-triaxial fracturing equipment. The resulting fracture parameters (fracture area, width, fractal dimension) were quantitatively analyzed through CT scanning and topography scanning. The research investigated the influence of varying foam quality, temperature, and flow rate on the initiation and propagation of fractures in coal rock. The results indicate that with a higher CO2 foam mass fraction, the fractures exhibit a higher level of complexity and lower fracturing pressure. Specifically, the initiation pressure at 70% foam mass is 7.1% lower than that at 40% foam mass, As the quality of CO2 foam improves, the post-fracturing fracture area and fractal dimension increase, indicating a rougher fracture surface and enhanced conductivity. As the temperature rises, the foaming volume of the foam decreases, leading to a shorter half-life, reduced interaction with coal rock, and slightly higher initiation pressure; CO2 foam fracturing can maintain larger fracture widths and has a greater fractal dimension compared to conventional fracturing fluids. This study reveals the fracture initiation and propagation mechanism of coal rock by CO2 foam fracturing. 1. INTRODUCTION The rapid development of China's economy and society drives a surge in oil and gas consumption, while conventional resources dwindle. This reliance on foreign oil and gas constrains China's economic and social progress. Coalbed methane products mainly comprise methane, an associated gas generated during coal production. Coalbed methane products primarily consist of methane, an associated gas formed during coal production. Comparable to natural gas, this clean energy source boasts high heat levels (Zonghu, 2006). The energy generated per 1000m3 of coalbed methane is equal to the energy generated by 1 ton of fuel oil and 1.25 ton of standard coal. With a calorific value of up to 33.44MJ/m3, CBM matches the quality of high-grade coal (Bozhang, 2005). Aligned with the "double carbon" objective, the exploration and exploitation of coalbed methane embody key values of "economy, safety, and environmental protection", contributing to a reduction in greenhouse gas emissions. Positioned as a pivotal facet and growth trajectory within the energy sector, coalbed methane holds immense promise for expansion and implementation, poised to emerge as a vital avenue addressing societal energy needs in the years ahead (Lei, 2018). China possesses abundant coalbed methane resources, ranking second globally after Russia and Canada (Qingbo & Wenguang, 2008; CHO and KIM, 2013), surpassing the United States and Australia by a significant margin. Despite this abundance, China has maintained relatively low production of coalbed methane. The inherent characteristics of Chinese coalbed methane reservoirs, characterized by low pressure, low saturation, low permeability, and high adsorption, constitute the primary bottleneck hindering the accelerated development of coalbed methane (Yali et al., 2021). Based on statistical data, China's geological coalbed methane resources stand at 29.8×10^12 m3, with technically recoverable resources estimated at 11.2×10^12 m3. The majority of these resources are situated within the three main regions of Northeast China, North China, and Northwest China. The top four regions with the most significant deposits include Ordos Basin, Qinshui Basin, Eastern Yunnan and Western Guizhou, and Junggar Basin, accounting for 24.4%, 13.4%, 11.6%, and 10.4% of total reserves, respectively (Xiaozhi et al., 2022). Currently, the development of coalbed methane faces a number of challenges, including the unclear migration mechanism and stimulation process for horizontal wells. The conventional method of hydraulic fracturing is often utilized, but it yields limited fractures, higher initial fracturing pressure, and simplistic fracture networks. Further, this approach wastes significant amounts of water resources and can even damage surface environments (Shaokai & Deli, 2019; Johnson & Johnson, 2012; Bostrom et al., 2014; Shibing et al., 2014; Haizhu et al., 2015; Zhonghou et al., 2010; Xiaojiang et al., 2017; Zhonghou et al., 2011). In response to diverse geological and technological demands, a range of CO2 fracturing technologies have surfaced, including CO2 foam fracturing, pre-CO2 energy-increasing fracturing, quasidry CO2 fracturing, dry CO2 fracturing, and various other variants. Notably, CO2 foam fracturing involves the injection of liquid CO2 into the well using a dedicated CO2 pump truck. This liquid CO2 is combined with gel fluid during the process and utilized for sand fracturing purposes (Changlin et al., 2016; Ting et al., 2016; Jidong et al., 2004). Due to the distinctive structure of the foam system, it boasts exceptional capabilities in minimizing sand sedimentation rates, even under high sand ratios. This unique structure enables excellent suspension and efficient transport of sand particles within the system (Shaohua, 2014; Siwei et al., 2024; Bo et al., 2023). Based on field data, the CO2 foam fracturing process has demonstrated significant advantages over conventional water-based fracturing methods. It enables complete self-flowing drainage post-fracturing, resulting in a high flowback rate and shorter drainage time. Moreover, this process causes minimal damage to the formation and fractures, while yielding remarkable fracturing outcomes (Hui & Xuxing, 2018; Xuxing et al., 2019; Zhandong, 2010; Honglian et al., 2022; Junping et al., 2019). The fracture characteristics observed in laboratory-scale experiments can offer insights into field construction scenarios. However, the in-depth exploration of the fracture initiation mechanism in CO2 foam fracturing of coal rock remains relatively limited. This study aims to address this gap by conducting CO2 foam fracturing experiments on coal rock using self-designed indoor quasi-triaxial and true-triaxial fracturing experimental equipment. The integration of CT scanning and morphology scanning allows for the quantitative analysis of fracture parameters, such as fractal dimension, fracture width, and fracture area. Furthermore, the study investigates the influence of various factors, including foam quality, temperature, stress differential, and flow rate, on the initiation and propagation patterns of cracks in coal rock. The experimental findings uncover the laws governing crack initiation and propagation in coal rock fractured by CO2 foam, offering an experimental foundation for the application of CO2 foam fracturing in coalbed methane development and contributing to the advancement of CO2 foam fracturing technology.
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Margaux, Kerdraon, Chevallier Eloise, Gland Nicolas e Batot Guillaume. "Co2 Foams in Carbonate Reservoirs at High Temperature: Boosting Cationics Formulation Performances By Additives". In SPE Conference at Oman Petroleum & Energy Show. SPE, 2022. http://dx.doi.org/10.2118/200052-ms.
Testo completoAbstract (sommario):
Abstract Injection of foams can be used to optimize different gas injection processes such as CCUS (Carbon Capture Use & Storage) and possibly to boost oil recovery kinetics in heterogenous or naturally fractured reservoirs (Enick R.M. 2012). In this case, foams, which are more viscous and dense than gases, aim at limiting early gas breakthrough during field operation by improving the sweeping efficiency of reservoirs and by blocking the most permeable areas of the latters (A. Al Sumaiti 2017, Chabert M. and D'Souza D. 2016). A large part of the world oil reservoirs that have already been operated by primary and secondary recovery methods are carbonate reservoirs and are mostly located in the Middle East (Talebian S.H. 2014). In these reservoirs, which are often operated by CO2 injection, the adsorption of surfactants on positively charged carbonates may be a major hindrance to foam injection (Pownall 1989, Cui L. and Ma K. 2014). That is why, cationic surfactants have been developed for these CO2 foam applications (Chen Y. 2016). However, these cationics are often hardly soluble at pH>6 (Jian G. 2019) and/or not industrially avalaible (Cui et Dubos 2018). For this study, we selected three different cationic surfactants. Using automated robotic platforms, we explored a large range of surfactant combination (combining each cationic surfactant with a whole co-surfactant portfolio) at high temperature and in a hard concentrated brine (120g/LTDS, [Ca2+]= 8100ppm). We show that adding co-surfactants to each of these cationics boosts their foaming properties in porous media as well as their solubility at high pH (pH=8) while maintaining low levels of adsorption on carbonates. While a high shear rate is required for cationic surfactants to generate foam in sandpacks, formulations combining cationics and co-surfactants form foams at much lower shear rates. Moreover, the fact that these formulations are soluble at pH=8 means that, on field, the water would no longer need to be acidified at the wellhead to solubilize the surfactant blend. Thus, pipe corrosion induced by the flow of acidified solutions in the surface facilities is prevented. Lastly, all the molecules that are tested in this study are industrially available.
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Bai, Bing, Bowen Yao, Mian Chen, Yan Jin, Di Liu, Yu Zhang e Mingwei Sun. "A Multi-Physics Fields Coupling Model for Supercritical CO2 Seepage in Shale Formation". In International Geomechanics Symposium. ARMA, 2022. http://dx.doi.org/10.56952/igs-2022-176.
Testo completoAbstract (sommario):
Abstract Supercritical carbon dioxide (ScCO2) can protect shale formation from hydration damage. When ScCO2 is utilized to develop shale oil and gas resources, it is necessary to establish the multi-physics fields coupling model to describe ScCO2 seepage in shale formation. The multi-physics model describing water-based fluid seepage is not capable explaining ScCO2 flow because of a great variation in physical properties of ScCO2 with pressure and temperature. In this study, a thermal–hydro–mechanical coupling model is constructed to describe ScCO2 seepage based on the transport and thermodynamic properties of CO2, combined with the effect of ScCO2 on mechanical properties of shale. The finite element method is used to solve the distribution of formation temperature, pore pressure and stress with time and position. The results show that compared with water seepage, the variation of formation temperature is greater, the pore pressure is lower, the stress difference near the wellbore in the direction of minimum in-situ stress is bigger, and the tangential stress in the direction of maximum in-situ stress is lower when adsorption-induced strain is neglected. The radial stress and tangential stress decrease with increasing time. This research can provide theoretical basis for wellbore stability analysis and fracturing evaluation when using ScCO2 as the drilling fluid and fracturing fluid, separately. Introduction As one of the unconventional resources, shale oil and gas resource is an important alternative to widely used conventional resources, which is attracting worldwide attention (Jin and Chen, 2019). Currently, the commercial exploitation technologies are massive hydraulic fracturing and horizontal drilling for developing shale gas resource. However, shale formation contains clay mineral, the hydration damage will be produced when clay mineral meets water. In the process of drilling or fracturing with water–based fluid, wellbore collapse or poor fracturing stimulation may be encountered due to hydration swelling. Meanwhile, hydraulic fracturing operation will consume a large amount of water resource, which limits the application of hydraulic fracturing in water–lacking area. In order to avoid formation damage and conserve water resource, the technology of drilling or fracturing with supercritical CO2 is proposed (Wang et al., 2018; Wen et al., 2020).
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Kang, Ying, Zhengfu Ning, Fangtao Lyu e Zejiang Jia. "Continuous in Situ Characterization by AFM of Surface Mechanical and Electrical Features of Shale Organic Matter Under Different Atmospheres". In 58th U.S. Rock Mechanics/Geomechanics Symposium. ARMA, 2024. http://dx.doi.org/10.56952/arma-2024-0681.
Testo completoAbstract (sommario):
ABSTRACT: Unconventional reservoirs, which are the mainstay of CO2 enhancement and carbon sequestration, are not well characterized in terms of micro-surface electrical properties. In this study, the micro-surface morphology and potential of organic matter (OM) under three atmospheres: dry, water-wet, and ScCO2 were characterized in detail using atomic force microscopy (Tapping mode, KPFM). The results showed that the micro-surface morphology of the OM fluctuated in the range of less than ten nanometers, and the micro-surface roughness under dry and ScCO2 conditions was higher than that under water-wet conditions, which indicated that the ScCO2 extraction and induced swelling were effective. In addition, the contact potential difference of the organic surface under water-wet and ScCO2 conditions was positive, and there was no correlation with the change of surface morphology. Combined with the reduction of Young's modulus, the difference of organic surface potential and the reduction of Young's modulus provide a good physical basis for the emergence of micro-cracks and other defects under the external forces, and provide a new idea for revealing the adsorption characteristics of unconventional reservoirs and realizing the long-term and stable carbon geologic sequestration. 1. INTRODUCTION Due to the decrease of conventional oil and gas resource production rates and the impact of the greenhouse effect in recent years, unconventional oil and gas reservoirs, such as shale, have become an important option for enhancing resource production rates and realizing carbon geologic sequestration (Farokhpoor et al., 2013; J. Zhang et al., 2023). A large number of studies have been carried out on rock damage, fracture generation and other related phenomena, but most of these studies have focused on the macro-scale level and lacked detailed analysis of related changes at the micro- and nano-scale (J. He et al., 2020; Yin et al., 2023; Gu et al., 2023). For unconventional reservoirs such as shale, which is both a key target for the implementation of CO2 enhanced recovery measures and an ideal place to realize efficient and stable carbon geological storage. Direct surface characterization of them can provide a better understanding of the CO2 action mechanism.
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Cunqi, Jia, Alsousy Abdulhamid e Sepehrnoori Kamy. "Mechanism Comparisons of Underground Hydrogen Storage in Heterogeneous Aquifers". In 57th U.S. Rock Mechanics/Geomechanics Symposium. ARMA, 2023. http://dx.doi.org/10.56952/arma-2023-0519.
Testo completoAbstract (sommario):
ABSTRACT Hydrogen provides a practical solution to reduce climate crisis causing by utilization of fossil fuels. Underground spaces provides a practical solution to large-scale and long-time of hydrogen storage. This work is motivated to study the influence of different physical mechanisms on the underground storage process, including geomechanical process, hydrogen adsorption on solid phase, hydrogen dissolution in water phase, hydrogen diffusion in water phase, hysteresis (relative permeability and capillary pressure), and capillary trapping. Results show that an obvious difference exists in hydrogen recovery factor with and without all physical mechanisms. Values of hydrogen recovery factor with all physical mechanisms are lower than values without different physical mechanisms. Hydrogen recovery factor without geomechanical process do not show an obvious difference with values with all physical mechanisms. Underground hydrogen storage process in aquifers is not dominated by the geomechanical process. Storage mechanisms, including hydrogen adsorption on solid phase, hydrogen dissolution in water phase, and hydrogen diffusion in water phase, have less influence on the hydrogen storage process. By contract, underground hydrogen storage process in aquifers is dominated by the hysteresis and capillary trapping mechanisms. INTRODUCTION Hydrogen, a clean energy carrier, has attracted lots of interest recently (Pan et al. 2021b, Tarkowski and Uliasz-Misiak 2022). Especially hydrogen utilization provides a practical solution to releasing CO2 emission duo the heavy use of fossil fuels (Li et al. 2021, Li et al. 2023, Tang et al. 2023). Underground geological structures, such as aquifers and depleted petroleum reservoirs, gradually obtain more attention from the scientific community and industry (Delshad et al. 2022). Because they can provide long-time, large-scale, and safe storage spaces for hydrogen, which further promotes the potential possibility of practical hydrogen utilization. Some scientific studies have been conducted to test and answer concerns about underground hydrogen storage. Lysyy et al. (2021) examine different storage mediums for underground hydrogen storage. Different storage schemes are conducted within the gas, oil, and water domains. Results show that the final hydrogen recovery factor has a larger value in the gas domain, followed by the oil domain. Withdrawal hydrogen has the worst behavior in the water domain. As for a sensitive study, the effect of the working rate is relatively well studied. But there is still no unanimous conclusion. Kanaani et al. (2022) take three different working rates to compare the difference between hydrogen recovery factor. Results suggest that a larger value of hydrogen recovery factor can be obtained using a higher working rate. Wang et al. (2022) also use three different rates to study the effect of the working rate on hydrogen storage behavior. But the results are different with Kanaani et al. (2022). In this study, compared to using a high working rate, more hydrogen can be produced when a low working rate is adopted. Cushion gas is another common topic discussed in the literature on underground hydrogen storage. Zamehrian and Sedaee (2022) indicate that the utilization of cushion gas mainly affects the hydrogen behavior in the first injection and production cycle. The final hydrogen recovery factor is less affected by the use of cushion gas. Different cushion gases have different behaviors. Results show that when nitrogen is adopted as a cushion gas, more hydrogen can be produced during the first production process compared to CO2 as a cushion gas. Ershadnia et al. (2023) also study the effect of the cushion gas during the underground hydrogen storage process. Results show that the whole cycle of hydrogen production amount can be affected by the use of cushion gas. More hydrogen can be produced when using cushion gas. In this study, CH4 and CO2 are selected as cushion gases. By contrast, choosing CH4 as a cushion gas has better behavior than CO2. Heinemann et al. (2021) mention that the hydrogen recovery factor can be affected by cushion gas. If more cushion gas can be used, less water can be produced. Hagemann et al. (2016) mention that the injection of hydrogen can stimulate the chemical reactivity induced by different microorganisms and bacteria. Ebigbo et al. (2013) address the activity of methanogenic microorganisms that can consume some hydrogen and carbon dioxide due to metabolism, which can change the composition of the hydrogen storage system. In addition, there are also some studies that have also contributed to improving the understanding of the underground hydrogen storage process. Sainz-Garcia et al. (2017) compare the hydrogen storage behavior using different well types. Results reveal that when a horizontal well is used to perform a hydrogen storage cycle, a lower recovery factor can be obtained than a vertical well system. Meanwhile, a horizontal well system reduces hydrogen injection capacity. Alhotan et al. (2023) conduct a sensitive study on permeability heterogeneity. Iglauer (2022) optimum the geological storage depth for structural hydrogen storage. 1000 m depth is finally suggested. Luboń and Tarkowski (2021) analyze the dynamic carbon dioxide and hydrogen injection capacity using a reservoir model from Poland. Results show under the same injection time, the CO2 distribution area is much larger than H2. Also, some experimental measurements are conducted to build an underground hydrogen storage database (Li et al. 2015, Li et al. 2017, Pan et al. 2021a).
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Zhang, Kunming, e Shimin Liu. "Determination of Thermo-Mechanical Coal Deformations and Implication for CO2 Storage in Deep Coal Formations". In 58th U.S. Rock Mechanics/Geomechanics Symposium. ARMA, 2024. http://dx.doi.org/10.56952/arma-2024-0409.
Testo completoAbstract (sommario):
ABSTRACT: CO2 sequestration along with enhanced coalbed methane (ECBM) has received considerable attention for energy recovery and CO2 storage. CO2 injection not only reduces permeability due to the swelling effect but modifies the temperature field, resulting in coupled thermo-mechanical coal deformations. Limited efforts have been devoted towards the understanding of thermo-mechanical deformations in the coalbed methane (CBM) industry. This study proposed a theoretical model of thermal expansion coefficients through energy principle. Direct measurements of coal deformations with variations in temperature and pressure were carried out. The results indicate that thermo-induced deformation linearly correlates with temperature variations with estimated thermo-deformative coefficients between 8×10-5/K to 10×10-5/K, falling within the theoretical bounds. Additionally, the coal matrix retains its elastic properties after thermal cycling. The mechanical compression at different temperatures exhibits similar trends, increasing linearly with pressure. The matrix bulk modulus increases with pressure cycles at elevated temperatures, indicating that the coal becomes stiffer due to residual strain and gradually increases with pressure depletion. Anisotropic matrix deformation was observed when the temperature was above 273.15 K. The deformation of the coal can have significant implications on the evolution of effective stress, permeability, and localized failure, ultimately controlling CO2 sequestration and long-term CBM production. 1. INTRODUCTION CBM is an unconventional natural gas resource stored within coal seams. Over the past four decades, CBM has developed rapidly and become an important energy source in the United States, Canada, Australia, China, et al. (Yang & Liu, 2021). CBM is known for its relatively low risk associated with low costs due to the maturity of CBM exploration, drilling, completion, and stimulation processes (Flores, 2013). In the United States, CBM production peaked at 1.97 trillion cubic feet (TCF) in 2008, and as of 2022, it still contributes 0.72 TCF, accounting for 2% of the overall U.S. natural gas production (U.S. Department of Energy, 2022, 2023). ECBM was first proposed by Puri (Puri & Yee, 1990) to address the inefficiencies resulting from the reservoir pressure reduction during the late time reservoir depletion. More recent attention has focused on the CO2-ECBM technology and CO2 storage, as depicted in Figure 1 (a) (Jessen, Tang, & Kovscek, 2008; Lin, Ren, Cheng, & Nemcik, 2021; Mazzotti, Pini, & Storti, 2009). CO2 can displace methane attributed to its higher affinity for coal, effectively enhancing methane recovery, particularly in low-permeability CBM reservoirs (White, Strazisar, Granite, Hoffman, & Pennline, 2003). Furthermore, this innovative process has a long-term environmental benefit of sequestering and storing CO2 within underground coal seams. The storage potential of CO2 in unminable coal seams is considerable, with estimated capacities ranging from 3 to 200 GtCO2, making it a relevant option for mitigating anthropogenic CO2 emissions (Mazzotti et al., 2009; Metz, Davidson, De Coninck, Loos, & Meyer, 2005). Many researchers have considered that during the CO2 injection process, CO2 adsorption can induce a significant matrix swelling (Figure 1 (b)), resulting in cleat closure and reduction in permeability (Pekot & Reeves, 2002; J.-Q. Shi & Durucan, 2005; Siriwardane, Gondle, & Smith, 2009; G. X. Wang, Wei, Wang, Massarotto, & Rudolph, 2010; White et al., 2005). This reduction in permeability limits the CO2 injection rate, which is critical for the success of CO2-ECBM (Bai et al., 2022; Lu & Connell, 2008; Zhang & Ranjith, 2019). Indeed, in addition to sorption-induced strain, the coal deformation can also be influenced by fluid composition, temperature, and water saturation, as demonstrated in Figure 1 (c), (d), and (e).
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Meybodi, M. Kalantari, K. S. Sorbie, O. Vazquez, K. Jarrahian e E. J. Mackay. "Coupled Adsorption/Precipitation Modelling of Phosphonate Scale Inhibitors in a Batch Reactive System". In SPE International Conference and Exhibition on Formation Damage Control. SPE, 2024. http://dx.doi.org/10.2118/217904-ms.
Testo completoAbstract (sommario):
Abstract Scale inhibitor squeeze treatments are one of the most common ways to prevent scale deposition. The mineral scale will be inhibited if the concentration of the scale inhibitor (SI) in the produced water is above a certain threshold, known as the Minimum Inhibitor Concentration (MIC), which is controlled by scale inhibitor retention. Therefore, accurate modelling of the SI retention through adsorption (Γ) and precipitation (А) is critical to the successful design and implementation of squeeze treatments. In this study, an equilibrium model has been developed to simulate the coupled adsorption-precipitation (Ð/А) of phosphonate scale inhibitors in reactive formations, such as carbonates, in the presence of calcium and magnesium cations. In this approach, the scale inhibitor (SI) was considered as a poly weak acid that may be protonated (HnA), resulting in the complexation with Ca/Mg ions, leading to the precipitation of SI_Ca/Mg complexes. All these reactions occur in an integrated system where carbonate system reactions and adsorption of the soluble species are occurring in parallel. In the adsorption process, all the SI derivatives remaining in the solution, including free and complex species, are considered to participate in the adsorption process, described by an an adsorption isotherm model (e.g., Freundlich). For the precipitation part, the model considers the following reactions: (i) the carbonate system, (ii) SI speciation, considered as weak polyacid, HnA, (iii) the SI-metal (Ca and Mg) binding complexes, and (iv) subsequent precipitation of the SI-Ca/Mg complex. The system charge balance and the mass balances for calcium, magnesium, carbon, and SI are considered, to numerically equilibrate the system (excluding the adsorbed species), by solving a determined set of non-linear equations numerically. Following the algebraic reduction of the equations, the system is reduced to three non-linear equations that may be solved by the Newton-Raphson method. The precipitation of the SI-Ca/Mg is modelled in the equilibrium model based on the solubility of SI in the solution, determined from the lab experiments. The reliability of the proposed model was established by comparison with experimental results from a previous study (Kalantari Meybodi et al., 2023) on the interactions of DETPMP in a Calcite/brine (containing free Ca/Mg) system, where the final concentration of SI, Ca2+, Mg2+, CO2 and pH were compared. The modelling showed good general agreement with the experimental results, and a further sensitivity analysis was performed to examine the behaviour of some uncertain parameters, such as the stability constant of complexes.
Rapporti di organizzazioni sul tema "Adsorption et séparation de CO2"
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Stavland, Arne, Siv Marie Åsen, Arild Lohne, Olav Aursjø e Aksel Hiorth. Recommended polymer workflow: Lab (cm and m scale). University of Stavanger, novembre 2021. http://dx.doi.org/10.31265/usps.201.
Testo completoAbstract (sommario):
Polymer flooding is one of the most promising EOR methods (Smalley et al. 2018). It is well known and has been used successfully (Pye 1964; Standnes & Skjevrak 2014; Sheng et al. 2015). From a technical perspective we recommend that polymer flooding should be considered as a viable EOR method on the Norwegian Continental Shelf for the following reasons: 1. More oil can be produced with less water injected; this is particularly important for the NCS which are currently producing more water than oil 2. Polymers will increase the aerial sweep and improve the ultimate recovery, provided a proper injection strategy 3. Many polymer systems are available, and it should be possible to tailor their chemical composition to a wide range of reservoir conditions (temperature and salinity) 4. Polymer systems can be used to block water from short circuiting injection production wells 5. Polymer combined with low salinity injection water has many benefits: a lower polymer concentration can be used to reach target viscosity, less mechanical degradation, less adsorption, and a potential reduction in Sor due to a low salinity wettability effect. There are some hurdles when considering polymer flooding that needs to be considered: 1. Many polymer systems are not at the present considered as green chemicals; thus, reinjection of produced water is needed. However, results from polymer degradation studies in the IORCentre indicates that a. High molecular weight polymers are quickly degraded to low molecular weight. In case of accidental release to the ocean low molecular weight polymers are diluted and the lifetime of the spill might be quite short. According to Caulfield et al. (2002) HPAM is not toxic, and will not degrade to the more environmentally problematic acrylamide. b. In the DF report for environmental impact there are case studies using the DREAM model to predict the transport of chemical spills. This model is coupled with polymer (sun exposure) degradation data from the IORCentre to quantify the lifetime of polymer spills. This approach should be used for specific field cases to quantify the environmental risk factor. 2. Care must be taken to prepare the polymer solution offshore. Chokes and vales might be a challenge but can be mitigating according to the results from the large-scale testing done in the IORCentre (Stavland et al. 2021). None of the above-mentioned challenges are server enough to not consider polymer flooding. HPAM is neither toxic, nor bio-accumulable, or bio-persistent and the CO2 footprint from a polymer flood may be significantly less than a water flood (Dupuis et al. 2021). There are at least two contributing factors to this statement, which we will return in detail to in the next section i) during linear displacement polymer injection will produce more oil for the same amount of water injected, hence the lifetime of the field can be shortened ii) polymers increase the arial sweep reducing the need for wells.