Role of Impurities on CO2 Injection: Experimental and Numerical Simulations of Thermodynamic Properties of Water-salt-gas Mixtures (CO2 + Co-injected Gases) Under Geological Storage Conditions

International audienceRole of impurities on CO 2 injection: experimental and numerical simulations of thermodynamic properties of water-salt-gas mixtures (CO 2 + co-injected gases) under geological storage conditions Abstract Regarding the hydrocarbon source and CO 2 capture processes, fuel gas from boilers may be accompanied by so-called "annex gases" which could be co-injected in a geological storage. These gases, such as SOx, NOx, or oxygen for instance, are likely to interact with reservoir fluids and rocks and well materials (casing and cement) and could potentially affect the safety of the storage. However, there are currently only few data on the behaviour of such gas mixtures, as well as on their chemical reactivity, especially in the presence of water. One reason for this lack comes from the difficulty in handling because of their dangerousness and their chemical reactivity. Therefore, the purpose of the Gaz Annexes was to develop new experimental and analytical protocols in order to acquire new thermodynamic data on these annex gases, in fine for predicting the behaviour of a geological storage of CO 2 + co-injected gases in the short, medium and long terms. This paper presents Gaz Annexes concerning acquisition of PVT experimental and pseudo-experimental data to adjust and validate thermodynamic models for water / gas / salts mixtures as well as the possible influence of SO 2 and NO on the geological storage of CO 2. The Gaz Annexes s new insights for the establishment of recommendations concerning acceptable content of annex gases

Étude par dynamique moléculaire du comportement d'aluminosilicates tubulaires hydratés : structure et dynamique du système eau-imogolite

The structure and the dynamics of the water molecules confined in aluminosilicates of tubular (imogolite) and spherical (allophane) shapes, were studied with the use of the molecular dynamics method at the microscopic level. For this purpose, structural and potentiel models for the hydrated aluminosilicates were developed.The study of the vibrational dynamics of imogolite provide results that are in an agreement with the experimental data. An attribution of some bands in the infrared and Raman spectra of imogolite was proposed on the basis of the simulations. The calculated Raman spectra show a low-frequency band whose position depends on the value of the nanotube's diameter. This band is assigned to the radial breathing mode of the nanotube.Results of the simulations of the water/imogolite systems show the hydrophilic and hydrophobie character of the internal and the external surfaces of the solid, respectively. Consequently, the water molecules near these surfaces have different behaviors. While the intertube water molecules behave similarly to their counterparts in bulk liquid water. the structural and dynamical characteristics of the water inside imogolite are strongly influenced by the internal surface.Although the internal surfaces of allophane and imogolite are very similar to each other, the mobility of the water molecules is higher inside the spherical aluminosilicate than in the tubular one. This result suggests weaker host-guest interactions in the water/allophane system than in the water/imogolite one.La structure et la dynamique des molécules d'eau confinées dans des aluminosilicates de formes tubulaire (imogolite) et sphérique (allophane) ont été étudiées à l'échelle microscopique par la méthode de la dynamique moléculaire. Pour ce faire, des modèles structuraux de ces aluminosilicates ainsi que des modèles d'interactions ont été développés. La simulation de la dynamique vibrationnelle de l'imogolite fournit des résultats en accord avec ceux expérimentaux. Ainsi, certaines bandes des spectres infrarouge et Raman ont pu être attribuées. Les spectres Raman calculés pour ces structures montrent une bande située aux basses fréquences dont la position varie en fonction du diamètre du nanotube. Cette bande est attribuée à la vibration de respiration radiale de la structure. Les résultats des simulations sur les systèmes eau/imogolite montrent des caractères hydrophile et hydrophobe respectivement pour les surfaces interne et externe de l'imogolite. Par conséquent, les molécules d'eau proches de ces surfaces ont des comportements différents. Alors que les molécules d'eau entre les nanotubes se comportent de façon similaire aux molécules d'eau dans l'eau liquide, les caractéristiques structurales et dynamiques des molécules à l'intérieur de l'imogolite sont fortement influencées par la surface. Bien que la composition chimique de la surface interne de l'imogolite et de l'allophane soit similaire, une plus grande mobilité des molécules d'eau est constatée dans le cas de la structure sphérique traduisant des interactions eau/surface plus faibles que pour le système eau/imogolite

Evaluation des pratiques en antibiothérapie aux urgences de l'hôpital de Douai

LILLE2-BU Santé-Recherche (593502101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Machine learning based models for accessing thermal conductivity of liquids at different temperature conditions

Combating the global warming-related climate change demands prompt actions to reduce greenhouse gas emissions, particularly carbon dioxide. Biomass-based biofuels represent a promising alternative fossil energy source. To convert biomass into energy, numerous conversion processes are performed at high pressure and temperature conditions and the design and dimensioning of such processes requires thermophysical property data, particularly thermal conductivity, which are not always available in the literature. In this paper, we proposed the application of Chemoinformatics methodologies to investigate the prediction of thermal conductivity for hydrocarbons and oxygenated compounds. A compilation of experimental data, followed by a careful data curation were performed to establish a database. The support vector machine algorithm has been applied to the database leading to models with good predictive abilities. The SVR model has then been applied to an external set of compounds, i.e. not considered during the training of models. It showed that our SVR model can be used for the prediction of thermal conductivity values for temperatures and/or compounds that are not covered experimentally in the literature

Étude par dynamique moléculaire du comportement d'aluminosilicates tubulaires hydratés (structure et dynamique du sytème eau-imogolite)

La structure et la dynamique des molécules d'eau confinées dans des aluminosilicates de formes tubulaire (imogolite) et sphérique (allophane) ont été étudiées à l'échelle microscopique par la méthode de la dynamique moléculaire. Pour ce faire, des modèles structuraux de ces aluminosilicates ainsi que des modèles d'interactions ont été développés. La simulation de la dynamique vibrationnelle de l'imogolite fournit des résultats en accord avec ceux expérimentaux. Ainsi, certaines bandes des spectres infrarouge et Raman ont pu être attribuées. Les spectres Raman calculés pour ces structures montrent une bande située aux basses fréquences dont la position varie en fonction du diamètre du nanotube. Cette bande est attribuée à la vibration de respiration radiale de la structure. Les résultats des simulations sur les systèmes eau/imogolite montrent des caractères hydrophile et hydrophobe respectivement pour les surfaces interne et externe de l'imogolite. Par conséquent, les molécules d'eau proches de ces surfaces ont des comportements différents. Alors que les molécules d'eau entre les nanotubes se comportent de façon similaire aux molécules d'eau dans l'eau liquide, les caractéristiques structurales et dynamiques des molécules à l'intérieur de l'imogolite sont fortement influencées par la surface Bien que la composition chimique de la surface interne de l'imogolite et de l'allophane soit similaire, une plus grande mobilité des molécules d'eau est constatée dans le cas de la structure sphérique traduisant des interactions eau/surface plus faibles que pour le système eau/imogoliteLILLE1-BU (590092102) / SudocSudocFranceF

Thermodynamic study of binary systems containing sulphur dioxide: measurements and molecular modelling

International audienceIn the present work, we report isothermal vapour-liquid equilibrium data for two binary systems: nitrogen-sulphur dioxide and oxygen-sulphur dioxide at four temperatures (323.15, 343.15, 373.15, and 413.15 K) and pressures up to 85 MPa. These data were simultaneously obtained from experimental measurements and molecular simulations. The compositions of coexisting phases were experimentally determined using an apparatus based on the "static-analytic" method. At the same time, Gibbs ensemble Monte Carlo (MC) simulations were performed on these binary mixtures, using force fields based on pure component properties. An original force field is proposed for sulphur dioxide molecule, involving three Lennard-Jones centres and three electrostatic charges. The experimental and simulation results appear in good agreement, allowing reliable and accurate predictions at higher pressures with molecular simulations

Thermodynamic study of SO2/O2 and SO2/N2 systems from experiments and Monte Carlo molecular simulations

In CCS (Carbon dioxide Capture and Storage) operations, the captured CO2 stream from industrial installations is a contaminated CO2: it contains: SO2, NOx, H2S, N2, O2, Ar... This exhausted CO2 may have quite different thermo-physical properties with respect to pure CO2. This may have impacts on the different stages of the CCS chain: capture, transportation, compression, injection and storage [1]. For a global account of these impacts and for a precise specification of maximal amounts of contaminants that can be tolerated in CO2 flues, further investigations are strongly required. Accurate knowledge of the phase equilibrium (Vapor-Liquid equilibrium: VLE) of contaminant-contaminant is part of the required studies in order to assess this problem. In this communication, we have chosen to present VLE of two binary mixtures: SO2/O2 and SO2/N2. Results are obtained using Monte Carlo molecular simulations and an experimental device based on the “static-analytic” method [2]. For these binary systems, data were generated for temperatures between 323 and 413 K and pressures up to 20 MPa. Phase envelopes have been calculated at the same temperatures and for pressures from 5 to 90 MPa. Good agreement is obtained between simulated and experimental data. For mixtures containing SO2, experimental data are scarce and molecular simulations are an interesting tool to overcome limits of experimental devices

Theoretical prediction of physico-chemical properties of chemicals for regulatory purposes

The use of alternative methods to experimental testing was encouraged by REACH for the gathering of (eco)-toxicological properties but also for physico-chemical properties in order to allow the use of substances in EU market before 2018. Indeed, taking into account the number of substances and properties, the timing, the economic costs, the feasibility at the R&D level and the risks for the manipulator, the measurement of all the data was not realistic. If QSPR methods were particularly targeted by REACH, molecular scale modeling, in general, can play a critical role. In this context, a detailed review of the literature of the molecular modeling approaches (group-contributions, QSPR, equations of states, COSMO-RS/SAC and molecular simulations) available for the theoretical prediction of physico-chemical properties required by the REACH regulation (annexes VII and IX) was performed within the French PREDIMOL project (http://www.ineris.fr/predimol/), apart from 3 properties that are not directly dependent on the molecular scale properties of the substance. The objective was to stress onto required input information, performances and limits of each approach for all these properties and to give practical information to one user. From this work, a review for Chemical Reviews was written by the partners of this project and revealed that these predictive methods are pertinent alternative/complementary approaches to provide quick and reliable predictions of the physico-chemical properties of substances based only on the knowledge of their molecular structures. Authors indicated also that the selection of a method should be guided by the property to predict and the targeted compound

A general guidebook for the theoretical prediction of physicochemical properties of chemicals for regulatory purposes

International audienceThis document aims at reviewing the molecular modeling approaches available as a fast and reliable alternative approach to experiments for the physicochemical properties required by the REACH regulation