Rigorous CO₂ absorption models were developed for aqueous 4.5 m K+/4.5 m PZ, monoethanolamine (7m - 9m), and piperazine (8m) in Aspen Plus® RateSepTM. The 4.5 m K+/4.5 m PZ model uses the Hilliard thermodynamic representation and kinetics based on work by Chen. The MEA (Phoenix) and PZ (5deMayo) models incorporate new data for partial pressure of CO₂ vs. loading and kinetics from wetted wall column data. They use reduced reaction sets based on the more relevant species present at the expected operating loading. Kinetics were regressed to match reported carbon dioxide flux data using a wetted wall column (WWC). Density and viscosity were satisfactorily regressed to match newly obtained experimental data. The activity coefficient of CO₂ was also regressed to include newly obtained CO₂ solvent solubility data. The models were reconciled and validated using pilot plant data obtained from five campaigns conducted at the Pickle Research Center. Performance was matched within 10% of NTU for most runs. Temperature profiles are adequately represented in all campaigns. The calculated temperature profiles showed the effect of the L/G on the location and magnitude of the temperature bulge. As the L/G is increased the temperature bulge moves from near the top of the column towards the bottom and its magnitude decreases. Performance improvement due to intercooling was validated across the campaigns that evaluated this process option. Absorber intercooling was studied using various solvent rates (Lmin, 1.1 Lmin and 1.2 Lmin). It is most effective at the critical L/G where the temperature bulge without intercooling is in the middle of the column. In this case it will allow for higher absorption by reducing the magnitude of the bulge temperature. The volume of packing to get 90% removal with L/Lmin =1.1 at the critical L/G is reduced by 30% for 8m PZ. For MEA and a solvent flow rate of 1.1 Lmin packing volume is increased with intercooling at constant L/G. This increase is compensated by higher solvent loadings that suggest lower stripping energy requirements. The critical L/G is 4.3 for 8m PZ, 6.9 for 9m MEA and 4.1 for K+/PZ. / text

Yes / It has been globally recognized as necessary to reduce greenhouse gas (GHG) emissions for mitigating the adverse effects of global warming on earth. Carbon dioxide (CO2) capture and storage (CCS) technologies can play a critical role to achieve these reductions. Current CCS technologies use several different approaches including adsorption, membrane separation, physical and chemical absorption to separate CO2from flue gases. This study aims to evaluate the performance and energy savings of CO2capture system based on chemical absorption by installing an intercooler in the system. Monoethanolamine (MEA) was used as the absorption solvent and Aspen HYSYS (ver. 9) was used to simulate the CO2capturing model. The positioning of the intercooler was studied in 10 different cases and compared with the base case 0 without intercooling. It was found that the installation of the intercooler improved the overall efficiency of CO2recovery in the designed system for all 1-10 cases. Intercooler case 9 was found to be the best case in providing the highest recovery of CO2(92.68%), together with MEA solvent savings of 2.51%. Furthermore, energy savings of 16 GJ/h was estimated from the absorber column alone, that would increase many folds for the entire CO2capture plant. The intercooling system, thus showed improved CO2recovery performance and potential of significant savings in MEA solvent loading and energy requirements, essential for the development of economical and optimized CO2capturing technology.

Les travaux de cette thèse s’inscrivent dans le cadre de la mise en place d’une méthodologie innovante de gestion thermique globale des véhicules automobiles. Ils portent plus particulièrement sur l’analyse de la réduction des émissions de polluants et l’amélioration des performances énergétiques d’un moteur à combustion, notamment dans les charges partielles ou en régime transitoire. Le premier objectif vise la mise en évidence de l’effet de la température d’admission sur le fonctionnement du moteur. Le deuxième objectif est relatif à la prédiction de l’apparition des phénomènes de condensation inhérents aux procédés de recirculation des gaz d’échappement à l’admission moteur. Enfin le troisième objectif est la modélisation et la mise en œuvre d’un circuit d’eau refroidit par la boucle de climatisation dont la fonction est de sous refroidir les gaz d’admission du moteur. Le premier chapitre est consacré à la présentation du système thermique véhicule et de la démarche de conception en V adoptée dans ce travail. Dans le second chapitre, et après avoir mis en évidence les effets d’un sous refroidissement des gaz admission sur le rendement thermodynamique du moteur, on montre à l’aide d’une étude technologique et numérique de la boucle de climatisation qu’il est possible d’opérer ce refroidissement par un système embarqué capable de se régénérer thermiquement lors d’un freinage. Le troisième chapitre est dédié à la modélisation du système à l’aide d’une modélisation énergétique centrée sur l’utilisation du langage bond graph. Le dernier chapitre est dédié au volet expérimental afin de valider d’une part le modèle de condensation et d’autres part un démonstrateur d’hybridation thermique et ses stratégies de pilotage / The work of this thesis is part of the development of an innovative methodology in the field of global thermal management for motor vehicles. It focuses specifically on the analysis of the reduction of pollutant emissions and improving energy efficiency of a combustion engine, especially in partial load or transient operation. The first objective is to analyze the effect of inlet temperature on the engine performance. The second objective relates to the prediction of the condensation processes inherent to exhaust gas recirculation into the engine intake. Finally, the third objective is the modeling and implementation of a water circuit cooled by the air conditioning loop and whose function is to cool the gases in at the engine intake.The first chapter is devoted to the presentation of the vehicle thermal management system and the design process adopted in this work. In the second chapter, after having shown the effects of intake gas cooling on the thermodynamic efficiency of the engine, it is shown with a numerical and technological study of the air conditioning loop that is possible to operate an onboard cooling system that is capable of regenerating heat when braking. The third chapter focuses on system modeling using an energy modeling focuses on the use of bond graph language. The final chapter is dedicated to the experimental part with the objective of validating the model of gas condensation and a demonstrator of thermal hybridation and its control strategies