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International audience; Chemical absorption with alkanolamines processes are commonly applied for natural gas purification. The knowledge of CO 2 , H 2 S, hydrocarbons and mercaptans solubilities in aqueous alkanolamine solutions is important in acid gas removal process simulation and design. In previous works, alkanes, aromatics and mercaptans solubilities in different aqueous alkanolamine solutions have been successfully represented by using the PR-CPA EoS. In this work, the PR-CPA EoS with a pseudo-chemical reaction approach is developed and applied to describe the solubility of acid gases in aqueous alkanolamines solutions. The results are in good agreement with a wide range of experimental data. Other relevant properties such as water content, electrolytes speciation and enthalpy of absorption are accurately predictd by PR-CPA EoS.

International audience; This study focuses on the chemical compositions of volcanic gases and aerosols emitted by Lascar volcano (Northern Chile). The sustained volcanic plume was sampled in April 2009, April 2011 and November 2012 through filter packs and analyzed for major gaseous species (SO2, HCl, and HF) and trace elements. During fieldwork, SO2 flux measurements were also performed by UV spectrometry (DOAS). The Lascar volcano is a significant and sustained emitter of SO2 (between 150 and 940 t/d), HCl (between 170 t/d and 210 t/d) and HF (up to 100 t/d). Combining the SO2-normalized trace element concentrations and the SO2 emission rates, we evaluate that the quiescent degassing of Lascar is an important local source of trace metals to the atmosphere with contributions to global volcanic fluxes generally less than 2%.Our data were used to infer the origin of the gas emitted at Lascar. Two major degassing sources were identified: a deep magmatic reservoir and a shallow hydrothermal system. The variable interaction between these two sources is the most likely scenario for explaining the compositional ranges in acid gases but also in a volatile and fluid–mobile trace element such as B. These variations are related to changes in volcanic activity: an extensive interaction between the hot ascending magmatic gases and the shallow aquifer occurred in 2009, possibly due to a long period of quiescence, before magmatic activity renewed in 2011 and 2012. Our study highlights, therefore, that filter-pack measurements may be used to study changes in subsurface processes that probably play a key role in triggering volcanic eruptions.

International audience; This paper gives the first step of the development of a rigorous multicomponent reactive separation model. Such a model is highly essential to further the optimization of acid gases removal plants (CO2 capture, gas treating, etc.) in terms of size and energy consumption, since chemical solvents are conventionally used.Firstly, two main modelling approaches are presented: the equilibrium-based and the rate-based approaches.Secondly, an extended rate-based model with rigorous modelling methodology for diffusion-reaction phenomena is proposed. The film theory and the generalized Maxwell-Stefan equations are used in order to characterize multicomponent interactions. The complete chain of chemical reactions is taken into account. The reactions can be kinetically controlled or at chemical equilibrium, and they are considered for both liquid film and liquid bulk.Thirdly, the method of numerical resolution is described. Coupling the generalized Maxwell-Stefan equations with chemical equilibrium equations leads to a highly non-linear Differential-Algebraic Equations system known as DAE index 3. The set of equations is discretized with finite-differences as its integration by Gear method is complex. The resulting algebraic system is resolved by the Newton- Raphson method.Finally, the present model and the associated methods of numerical resolution are validated for the example of esterification of methanol. This archetype non-electrolytic system permits an interesting analysis of reaction impact on mass transfer, especially near the phase interface. The numerical resolution of the model by Newton-Raphson method gives good results in terms of calculation time and convergence. The simulations show that the impact of reactions at chemical equilibrium and that of kinetically controlled reactions with high kinetics on mass transfer is relatively similar. Moreover, the Fick’s law is less adapted for multicomponent mixtures where some abnormalities such as counter-diffusion take place.

International audience; In this work, vapor-liquid equilibrium (VLE) measurements of propyl mercaptan (PM) in pure water were performed at three different temperatures, (303, 323, and 365) K, with a pressure variation from (1 to 8) MPa. The total system pressure was maintained by CH4. The inlet mole fraction of propyl mercaptan in all experiments was the same, around 4.5 center dot 10(-4) in the liquid phase. The objective was to provide experimental VLE data points of the propyl mercaptan + methane + water system for modeling since there is a lack of available data. These data will allow the industrial modeling of sulfur emission. The thermodynamic model used for the description of VLE is the extended UNIQUAC model. The model parameters are valid in the temperature range similar to the measured data and a pressure range up to 8 MPa.

National audience; Coal power stations as well as waste incinerators produce humid acid gases which condensate in industrial chimneys. These condensates may cause corrosion of the internal cladding made of stainless steels, nickel base alloys or non metallic materials. In the aim of polluting emission reduction and material optimal choice, it is necessary to determine all the phenomena which occur throughout the chimney such as condensation and dissolution of acid gases (in this particular case, sulphur dioxide SO2). The production of energy from fossil fuels (coal, petroleum, natural gas, etc.) brings about the emission of gas containing sulphur compounds (SO2, SO3) as well as chlorine and fluorine compounds. To avoid this atmospheric pollution and its harmful effects (acid rains, impact on the health) due to hydrochloric, sulphuric and hydrofluoric acids produced in the presence of air, it is necessary to steam these flue gases. Nevertheless, a considerable quantity of residual acid gases remains in the gas discharge which also contains large amounts of water vapour. Thus, condensation may occur and by the way an acid attack of the internal cladding of the chimney. This results in high costs of maintenance and a reduction of their structural stability. The knowledge of the phenomena of heat and mass transfer during the condensation of these acid gases in chimney is essential for their conception and materials choice.